Published: December 06, 2011 This article not subject to U.S. Copyright. Published 2011 by the American Chemical Society 747 dx.doi.org/10.1021/ac202903d | Anal. Chem. 2012, 84, 747–778 REVIEW pubs.acs.org/ac Environmental Mass Spectrometry: Emerging Contaminants and Current Issues Susan D. Richardson National Exposure Research Laboratory, U.S. Environmental Protection Agency, Athens, Georgia 30605, United States ’ CONTENTS Introduction 747 Major Analysis Trends 748 Sampling and Extraction Trends 748 Chromatography Trends 748 Use of Nanomaterials in Analytical Methods 748 Other Trends with Emerging Contaminants 749 General Reviews 749 Sucralose and Other Artificial Sweeteners 749 Antimony 750 Nanomaterials 751 General Reviews 751 Nanosilver and Nanogold 751 Fullerenes and Other Carbon-Based Nanomaterials 752 Nanomaterials in Foods, Plants, and Biota 752 PFOA, PFOS, and Other Perfluorinated Compounds 752 Measurements in Biota 753 Paper Coatings for Food Packaging 754 Drinking Water 754 Landfill Leachates 754 Seawater and Sediments 755 Air and Soils around a Fluorochemical Manufacturing Plant 755 Sewage Sludge 755 New PFC Substitutes 755 Fate and Sources 755 New Methods 756 Pharmaceuticals and Hormones 756 Environmental Impacts of Pharmaceuticals 756 General Reviews 757 New Methods 757 Illicit Drug Methods 758 Marine Sample Methods 758 Biota Methods 758 Direct Analysis and Novel Approaches 759 Occurrence Studies 759 Fate of Pharmaceuticals: Wastewater Treatment, Drinking Water Treatment, and Photolysis 760 Hormones 762 Drinking Water and Swimming Pool Disinfection Byproducts 762 Drinking Water DBPs 762 Combining Chemistry with Toxicology 763 Discovery of New DBPs 763 N-DBPs 763 Nitrosamines 764 Alternative Disinfection Technologies Using Iodine, UV, and Other Treatments 765 Other Formation/Fate Studies 765 DBPs of Pollutants 765 New Swimming Pool Research 766 Sunscreens/UV Filters 767 Brominated Flame Retardants 767 Benzotriazoles 769 Dioxane 769 Siloxanes 769 Naphthenic Acids 769 Musks 770 Pesticide Transformation Products 770 Perchlorate 771 Algal Toxins 772 Microorganisms 773 Biography 773 Acknowledgment 773 References 774 ’ INTRODUCTION This biennial Review covers developments in environmental mass spectrometry for emerging environmental contaminants over the period of 20102011. Analytical Chemistry’s policy is to limit reviews to a maximum of 250 signi ficant references and to mainly focus on new trends. Even with a narrow focus, only a small fraction of the quality research publications could be discussed. As a result, as with the previous review on Environmental Mass Spectrometry in 2010, 1 this Review will not be comprehensive but will highlight emerging contaminant groups and discuss representative papers. I write a similar review article on Water Analysis, which also focuses on emerging contaminants. 2 That review article is somewhat different from this one, in that it focuses on only water contaminants and Special Issue: Fundamental and Applied Reviews in Analytical Chemistry
Transcript
Published: December 06, 2011
This article not subject to U.S. Copyright.Published 2011 by the American Chemical Society 747 dx.doi.org/10.1021/ac202903d |Anal. Chem. 2012, 84, 747–778
REVIEW
pubs.acs.org/ac
Environmental Mass Spectrometry: Emerging Contaminants andCurrent IssuesSusan D. Richardson
National Exposure Research Laboratory, U.S. Environmental Protection Agency, Athens, Georgia 30605, United States
’CONTENTS
Introduction 747Major Analysis Trends 748
Sampling and Extraction Trends 748Chromatography Trends 748Use of Nanomaterials in Analytical Methods 748Other Trends with Emerging Contaminants 749
General Reviews 749Sucralose and Other Artificial Sweeteners 749Antimony 750Nanomaterials 751
General Reviews 751Nanosilver and Nanogold 751
Fullerenes and Other Carbon-Based Nanomaterials 752Nanomaterials in Foods, Plants, and Biota 752
PFOA, PFOS, and Other Perfluorinated Compounds 752Measurements in Biota 753Paper Coatings for Food Packaging 754Drinking Water 754Landfill Leachates 754Seawater and Sediments 755Air and Soils around a Fluorochemical
Pharmaceuticals and Hormones 756Environmental Impacts of Pharmaceuticals 756General Reviews 757New Methods 757Illicit Drug Methods 758Marine Sample Methods 758Biota Methods 758Direct Analysis and Novel Approaches 759Occurrence Studies 759Fate of Pharmaceuticals: Wastewater Treatment,
Drinking Water Treatment, and Photolysis 760
Hormones 762Drinking Water and Swimming Pool Disinfection
Byproducts 762
Drinking Water DBPs 762Combining Chemistry with Toxicology 763Discovery of New DBPs 763N-DBPs 763Nitrosamines 764Alternative Disinfection Technologies Using
Iodine, UV, and Other Treatments 765
Other Formation/Fate Studies 765DBPs of Pollutants 765New Swimming Pool Research 766
This biennial Review covers developments in environmentalmass spectrometry for emerging environmental contaminants overthe period of 2010�2011. Analytical Chemistry’s policy is to limitreviews to a maximum of 250 significant references and to mainlyfocus on new trends. Evenwith a narrow focus, only a small fractionof the quality research publications could be discussed. As a result,as with the previous review on Environmental Mass Spectrometryin 2010,1 this Review will not be comprehensive but will highlightemerging contaminant groups and discuss representative papers.I write a similar review article onWater Analysis, which also focuses onemerging contaminants.2 That review article is somewhat differentfrom this one, in that it focuses on only water contaminants and
Special Issue: Fundamental and Applied Reviews in AnalyticalChemistry
includes additional analytical methods beyond mass spectrometry.This Review on environmental mass spectrometry focuses onmethods and occurrence/fate studies utilizing mass spectrometrybut also includes the study of air, soil/sediment, and biologicalsamples, in addition to water. I welcome any comments you haveon this review ([email protected]).
Numerous abstracts were consulted before choosing the bestrepresentative ones to present here. Abstract searches werecarried out using Web of Science, and in many cases, full articleswere obtained. A table of acronyms is provided (Table 1) as aquick reference to the acronyms of analytical techniques andother terms discussed in this Review.Major Analysis Trends. One of the hottest trends continues to
be the use of high resolution mass spectrometry (MS) with liquidchromatography (LC) to identify unknown contaminants, typicallyenvironmental transformation products. In this regard, time-of-flight(TOF) and quadrupole (Q)-TOF mass spectrometers, as well asOrbitrapmass spectrometers, are increasing in use. In addition, thereis increased use of nuclearmagnetic resonance spectroscopy (NMR)with LC/MS/MS to confirm tentative structures proposed byLC/MS/MS. Because NMR is not as sensitive as MS, preparativeLC is often used to collect enough material in fractions to enablethe analysis of unknowns in complex environmental mixtures.Examples in this Review include the identification of pharm-aceutical and pesticide transformation products.Atmospheric pressure photoionization (APPI) is also increas-
ingly being used with LC/MS because it provides improvedionization formore nonpolar compounds, such as polybrominateddiphenyl ethers (PBDEs) and musks discussed in this Review.Sampling and Extraction Trends. Solid phase extraction
(SPE) remains the most popular means of extraction and concentra-tion, and a new SPE device called Bag extraction was reported duringthe last 2 years. This bag-SPE consists of polystyrenedivinylbenzeneenclosed in a woven polyester fabric, which can be immersed inwater samples for solid phase extraction. Measured concentrationsof pharmaceuticals have been shown to be comparable for bag-SPEvs Oasis HLB extraction. Benefits include the ease of handling,unattended water extraction, and that no filtration is needed. Inaddition, new SPE sorbents are available, including Oasis MCXand hypercrosslinked polymer resin (HXLPP), that are being usedto capture a broader range of analytes within a single extraction.Solventless extraction techniques, such as solid phase microextrac-tion (SPME), also continue to be used in many applications.Chromatography Trends. Ultraperformance liquid chroma-
tography (UPLC) continues to increase in use. UPLC uses smalldiameter particles (typically 1.7 μm) in the stationary phase andshort columns, which allow higher pressures and, ultimately,narrower LC peaks (5�10 s wide). In addition to providingnarrow peaks and improved chromatographic separations,UPLC dramatically shortens analysis times, often to 10 min orless. Another significant chromatography trend is the use of two-dimensional GC (GCxGC). GCxGC enables enhanced separa-tions of complex mixtures through greater chromatographicpeak capacity and allows homologous series of compoundsto be easily identified. It also enables the detection of tracecontaminants that would not have been identified throughtraditional GC. TOF-MS is often used as the detector forGCxGC because of its rapid acquisition capability. An exampleof the use of GCxGC in this Review includes the identification ofnaphthenic acids.Use of Nanomaterials in Analytical Methods. In addition to
nanomaterials being a class of emerging contaminant, they are alsobeing applied in creative ways to aid in the measurement of otheremerging contaminants. For example, as described later in thisReview, gold nanoparticle labeling was used with inductivelycoupled plasma mass spectrometry (ICPMS) to measure E. coliO157:H7 in water. This method took advantage of the signalamplification property of gold nanoparticles, monoclonal antibody
recognition, and the high sensitivity of ICPMS. Silica-supportedFe3O4 magnetic nanoparticles were also used to extract andpreconcentrate pharmaceuticals from environmental waters.Other Trends with Emerging Contaminants. The analysis
of environmental transformation products has become a majortrend in environmental chemistry, and increasingly, researchersare taking this a step further in proposing complex transforma-tion pathways, with detailed mechanisms deduced by LC/MS/MS and sometimes confirmed by NMR. In addition, moreresearchers are combining toxicology with chemistry, in parti-cular with the testing of transformation products and disinfectionbyproducts for toxicity, but also in effect-directed research toidentify unknowns responsible for adverse environmental effects.There are also significant advances the last 2 years for nanoma-terials, such that uptake in plants and animals (even humans) isnow being demonstrated. Finally, a major trend in the area ofperfluorinated chemicals is in investigating potential sources andtheir fate in the environment. New types of PFCs are also beinginvestigated, including perfluorinated iodides.
’GENERAL REVIEWS
This section includes general reviews relating to environmen-tal mass spectrometry and emerging contaminants. Reviews thatrelate to specific areas (e.g., PFCs, pharmaceuticals, DBPs) canbe found in those specific sections. Many reviews have beenpublished over the last 2 years that relate to environmental massspectrometry, and some focus specifically on emerging contami-nants. Because of the large number of reviews, only a few could becited here. My other biennial review onWater Analysis publishedin 2011 (together with Thomas Ternes) discussed advances inmass spectrometry research for the same emerging contaminantsdiscussed in this current Review, along with ionic liquids.2
Another biennial review published in Analytical Chemistry byBallesteros-Gomez and Rubio covers new developments inenvironmental analysis and provides excellent discussions ofsampling, sample preparation, separation, and detection tech-niques (including mass spectrometry).3 This review includesmethods for a much broader range of environmental contami-nants, such as volatile organic compounds (VOCs), pesticides,polycyclic aromatic hydrocarbons (PAHs), polychlorinated bi-phenyls (PCBs), nitroaromatics, phthalates, organotins, andheavy metals, in addition to some emerging contaminants.
Emerging contaminants were the focus of several reviews thepast 2 years. For example, Alvarez and Jones-Lepp published anew review on sampling and analysis of emerging contaminantsin surface water, groundwater, and soil and sediment pore water.4
Personal care products were the focus of two reviews. One byBrausch and Rand included discussions of environmental con-centrations and toxicity,5 and the other by Pedrouzo discussedanalytical methods for measuring them in environmental waters.6
Emerging food contaminants were the focus of another review byKantiani et al., which included PFCs, PBDEs, nanomaterials,pharmaceuticals, and marine biotoxins.7 Clarke and Smith pub-lished a review of emerging contaminants in biosolids and rankedthe chemicals based on their environmental persistence, humantoxicity, bioaccumulation, ecotoxicity, and the number andquality ofinternational studies.8
Several reviews were related to the use of different massspectrometry techniques for emerging contaminants. Mass spec-trometry analysis of phenolic endocrine disruptors and relatedcompounds was the focus of a review by Gallart-Ayala et al.,
which included practical aspects of the use of GC/MS and LC/MS with different ionization and monitoring modes.9 Petrovicet al. reviewed LC/MS methods used for pharmaceuticals, drugsof abuse, polar pesticides, PFCs, and nanomaterials.10
While not reviews themselves, other papers are worthy of notefor broad applicability in the analysis of emerging contaminants.For example, Hernandez et al. discussed the use of GC with highresolution-TOF-MS for wide-scope target screening and un-known identification in environmental and food samples.11 Diazet al. presented optimal experimental conditions for the creationof an empirical TOF-MS library to aid in the identification ofenvironmental contaminants by UPLC or LC/MS/MS.12 Exactmass data for protonated or deprotonated molecular ions and upto 5 product ions, along with UPLC retention times, arepresented for approximately 230 chemicals, including pharma-ceuticals, hormones, pesticides, and transformation products.Palma et al. reported recent developments and applications of theuse of electron ionization (EI) with LC/MS.13 In particular, twomodern approaches, supersonic molecular beam and direct-EILC/MS, can offer several advantages to classic atmosphericpressure ionization techniques (including electrospray ionization[ESI], atmospheric pressure chemical ionization [APCI], andatmospheric pressure photoionization [APPI]). These direct EIapproaches allow automated library identification, easier identi-fication of unknown compounds (through extensive fragmenta-tion information), and lack of matrix interferences that causeproblems with traditional LC/MS approaches.
Effect-directed analysis is increasing in use. Examples includethe identification of 8 androgen-disrupting compounds14 and aneurotoxic brominated ether in river sediments.15 In the firststudy by Weiss et al., androgenic and antiandrogenic assays werecoupled with LC/accurate mass-MS, which enabled the identi-fication of the chemicals responsible for the androgen-disruptingeffects. In the second study by Qu et al., a neurotoxicity assay-directed analysis was coupled to LC/APCI-MS/MS, whichenabled the identification of tetrabromobisphenol A diallyl etheras the causative toxicant in sediment samples collected from ariver near a brominated flame retardant plant in China.
’SUCRALOSE AND OTHER ARTIFICIAL SWEETENERS
Sucralose (also known as Splenda or SucraPlus) is a relativelynew artificial sweetener that is nowwidely used inNorth Americanand Europe. It may seem like an odd compound to include as anemerging contaminant, but it is now being found in environmentalwaters and is extremely persistent (half-life up to several years).2 Itis made by chlorinating sucrose, where three hydroxyl groups arereplaced by chlorine atoms. Sucralose is heat stable, which is why ithas replaced other artificial sweeteners (such as aspartame) forbaking and is now widely used in soft drinks because of its longshelf life. Several research groups have reported measurements ofsucralose in the environment (including river water, groundwater,and coastal waters), and research has expanded to include otherartificial sweeteners, such as acesulfame, saccharin, cyclamate, andaspartame. Due to its stability in the environment, sucralose hasreceived a lot of attention as a potential tracer of anthropogenicinputs into environmental waters.
A very interesting paper by Soh et al. follows the fate of sucralosethrough various environmental processes (microbial degradation,hydrolysis, sorption), water treatment processes (chlorination,ozonation, sorption to activated carbon, and UV irradiation),and impact on plants.16 Results showed some degradation due
to hydrolysis, ozonation, and microbial processes, but it was slow,suggesting that sucralose will be persistent in the environment andcan be used as a tracer for anthropogenic activity. Sucralose wasnot found to inhibit plant uptake of sucrose in a variety of plantcotyledons investigated, nor did sucralose exhibit any toxicity onaquatic plant species studied. The authors brought up an interest-ing point that sucralose is one of very few contaminants that arehighly persistent but do not bioaccumulate and have little or noreported toxicity at environmentally relevant concentrations.Then, an intriguing question is posed: “Is persistence reasonenough for concern or regulation?”, but at the same time, it isrecognized that the risks of chronic low-dose exposure to sucraloseare unknown.
Torres et al. investigated the fate of sucralose in wastewatertreatment from 7 wastewater treatment plants in Arizona.17
Sucralose did not degrade in aerobic or anaerobic biologicalreactors, either metabolically or cometabolically after 42�62days. Prolonged exposure to UV radiation did not oxidizesucralose significantly, and chlorine and ozone only showed aslow oxidation, such that, under typical wastewater treatmentconditions, no significant sucralose degradation would be ex-pected. Average treatment plant effluent levels were 2.8 μg/L.Two artificial sweeteners, sucralose and acesulfame, were includedwith 4 other contaminants (carbamazepine, diatroic acid, 1H-benzotriazole, and tolyltriazole) in a study tracing their fate fromwastewater treatment plants to receiving waters to riverbankfiltration wells.18 Data were collected over 7 months at 7 samplinglocations on the Rhine and Main Rivers in Germany. Sucralose,acesulfame, and carbamazepine showed pronounced stabilityduring activated sludge wastewater treatment, and the concentra-tions for acesulfame and carbamazepine were well correlated, suchthat ratios could be used to identify a carbamazepine point source.In addition, soil aquifer treatment was tested at a site in Israel,where sucralose was found to degrade somewhat, possibly due tobiodegradation or slow hydrolysis in the upper layer of therecharge basins, rather than by sorption. However, remaininglevels were relatively high (2.1�3.5 μg/L), such that sucralosecould still be used as an anthropogenic marker.
Ferrer andThurman developed a SPE-LC/TOF-MSmethod tomeasure sucralose, aspartame, and saccharin in wastewater, surfacewater, groundwater, and soft drinks.19 The presence of the artificialsweeteners could be confirmed by accurate mass measurements.Analysis of several wastewater, surface water, and groundwatersamples revealed relatively high levels of sucralose, up to 2.4 μg/L.Sucralose was frequently detected, whereas saccharin was onlydetected in one wastewater sample and aspartame was notdetected in any samples. It is likely that aspartame and saccharinare easily biodegraded, due to reactive chemical moieties in thesemolecules. Zygler et al. created a method to analyze for 9 artificialsweeteners in various food products (e.g., beverages, dairy, and fishproducts).20 Acesulfame, sucralose, aspartame, alitame, cyclamate,dulcin, neohesperidin dihydrochalcone, neotame, and saccharinwere measured using LC/ESI-MS/MS.
Buerge et al. used LC/MS/MS to analyze sucralose, acesul-fame, saccharin, and cyclamate in soils to estimate inputs fromagriculture and households, degradation, and leaching togroundwater.21 It is interesting to note that saccharin is registeredas an additive in piglet feed, and it is largely excreted and can befound inmanure up to 12mg/L, with stability during 2months ofstorage. As a result, saccharin has a high probability of winding upin significant quantities from the application of manure toagricultural land. Sweeteners can also get into soils from the
irrigation of wastewater-contaminated surface water or throughleaky sewers. In this study, half-lives ranging from 0.4 to 124 dayswere reported for the sweeteners. Data suggested that thedetection of saccharin in the groundwater was most likely dueto the application of manure but that the high levels of acesulfamewere primarily due to infiltration of wastewater-contaminatedsurface water through stream beds.
Van Stempvoort et al. investigated the presence of artificialsweeteners in groundwater from 8 urban sites in Canada.22
Acesulfame was detected at all 8 urban sites, and data suggestedthat it might be a good tracer for “young” wastewater (<20 yearsresidence time). Three other sweeteners (sucralose, saccharin, andcyclamate) were also consistently detected in urban groundwaters.Finally,Oppenheimer et al. compared the suitability of sucralose toother anthropogenic contaminants as wastewater indicators.23 Ofthe 85 trace organic compoundsmeasured, sucralose was the mostconsistently detected in source waters with known wastewaterdischarges and also in septic samples, making it the best choice ofthe 85 chemicals for use as an indicator.
’ANTIMONY
Antimony, which can have both acute and chronic toxicityeffects, is regulated in drinking water in the United States,Canada, Europe, and Japan at action levels ranging from 2 to6 μg/L. Antimony contamination can result from copper or leadsmelting, petroleum refineries, or the manufacture of plastics andflame retardants. Antimony can also be present in air particulatematter from automobile emissions (engines and brake linings).24
New studies, however, have shown that it can also leach frompolyethylene terephthalate (PET) plastic water bottles, produ-cing the highest levels of human exposure to antimony, up to∼10 μg/L.2 Antimony trioxide is used as a catalyst in themanufacture of PET plastics, which can contain >100 mg/kgof antimony. Recent studies have shown that antimony can leachfrom these plastic bottles over prolonged storage and especiallyat warm temperatures.2 This is a concern because of the growingpopularity of bottled water. Compared to PET bottles, lowdensity polyethylene bottles contain much lower levels (∼1%)of antimony.24
Human exposure to antimony was reviewed by Belzile et al.,who discussed sources and intake of antimony through airparticulate matter, drinking water, bottled water, and food.24
Exposure from bottled water (with PET bottles) was highlightedas a major source of antimony, especially after prolonged storage.High levels have also been observed in fish and in food grown nearcontaminated sites. Reimann used ICPMS to investigate the typeof bottle on the leaching of antimony (and othermetals/elements)into bottled water.25 Glass bottles, hard PET bottles, and soft PETbottles of different colors were investigated by purchasing bottledwaters in supermarkets across Europe, rinsing the bottles andrefilling with high purity (deionized) water at pH 6.5, and also atpH 3.5 to investigate the effect of pH. Antimonywas found to havea 21� higher concentration when sold in PET bottles, but glasscould also leach antimony in acidified waters, up to 0.45μg/L after150 days in a dark green glass bottle. For plastic bottles, the softPET bottles and dark blue hard PET bottles leached the mostantimony at near-neutral pH (6.5). Finally, Cheng et al. assessedantimony and other metal leaching into water from plastic bottlesthat had been previously recycled.26 They investigated factors thatcould affect leaching, including cooling with frozen water, heatingwith boiling water, microwaving, having low pH, exposure to
outdoor sunlight irradiation, and exposure to in-car storage.Heating and microwaving led to the highest antimony leachingrelative to controls, whereas low-pH, outdoor sunlight irradiation,and in-car storage had no significant effect. Results also revealedpartial antimony leaching from PET bottles comes from thesurface of plastic during the manufacturing process, while majorantimony leaching comes from conditional changes.
’NANOMATERIALS
Nanomaterial research continues to rise exponentially, withcompanies and universities expanding their efforts. Universitydepartments have been developed around the study of nanoma-terials, and government investment in nanotechnology hasdramatically increased in the last 10 years. In my searching onWeb of Science this year, nearly 5000 citations appeared in theliterature for just the last 2 year period that this Review covers.This included >500 review articles on nanomaterials. There iseven a monthly journal called ACS Nano (created in 2008).Special issues of journals highlighted nanomaterials, as well asnumerous symposia held at scientific meetings the last 2 years.Most nanomaterial research is centered on developing new usesfor nanomaterials and new products with unique properties, buton the other side, there is also significant concern regardingnanomaterials as environmental contaminants. As such, nano-materials are the focus of a large initiative at the U.S. EPA, underwhich research on nanomaterial fate, transport, and health effectsis being conducted. Nanomaterials are 1 to 100 nm in size andcan have unique properties, including high strength, thermalstability, low permeability, and high conductivity. In the nearfuture, nanomaterials are projected to be used in areas such aschemotherapy, drug delivery, and labeling of food pathogens(“nanobarcodes”). The chemical structures of nanomaterials arehighly varied, including fullerenes, nanotubes, quantum dots,metal oxanes, TiO2 nanoparticles (NPs), nanosilver, nanogold,and zerovalent iron NPs.
Most environmental concerns center on the potential humanand ecological effects, and most methods use techniques otherthan mass spectrometry, such as transmission electron micro-scopy (TEM), scanning electron microscopy (SEM), atomicforce microscopy (AFM), quartz crystal microbalance, energydispersive X-ray spectroscopy (EDS), X-ray photoelectron spec-troscopy, static light scattering (SLS), particle electrophoresis,LC/UV, Raman spectroscopy, and NMR spectroscopy. In addi-tion, most studies are carried out in “clean” systems and not inreal environmental systems. Mass spectrometry techniques usedfor measuring nanomaterials include ICPMS and single particle-ICPMS (for metal-containing nanomaterials) and ESI- andAPPI-MS/MS for fullerenes.
Previous studies have shown the release of nanosilver from socksand other clothing treated with nanosilver, as well as from otherconsumer products including toothpaste, shampoo, anddetergent.2
One particularly important finding this year was the discovery thatzinc NPs in sunscreens can penetrate the skin and get transportedinto the bloodstream.27 In this fascinating study, Gulson et al. usedhuman volunteers to test sunscreen formulations containing radi-olabeled zinc (68Zn) in outdoor settings on a beach. One formula-tion contained ZnO NPs (which is commonly used in sunscreensthat go on clear, rather than white and pasty), and the othercontained larger ZnO particles (>100 nm). After 2 days ofsunscreen application, 68Zn was observed in all the volunteers’blood and urine, not only from the nano-ZnO but also from the
larger size ZnO formulations. Levels in the blood were low, but it isclear that the zinc can penetrate the skin, which was not believedpossible before. This study highlights the possibility for internalexposures to NPs (as well as slightly higher sized particles).General Reviews.As mentioned earlier, there were numerous
reviews published for nanomaterials, even in the environmentalarena. As a result, only a very few reviews could be cited here,such that I could also highlight new studies. In 2011, two specialissues ofTrends in Analytical Chemistry (TrAC), edited by Barceloand Farr�e, focused on characterization, analysis, and risks ofnanomaterials in environmental and food samples. In one ofthese special issues, Farr�e et al. led off with a review of the analysisand assessment of the occurrence, fate, and behavior of nano-materials in the environment.28 Qualitative and quantitativemethods were detailed, along with recent studies. In addition,the authors discuss a number of research gaps and issuesregarding the assessment of engineered NPs, including the lackof analytical methods capable of quantifying real environmentalsamples (and therefore, lack of real concentration data), the needfor standards and reference materials, the need for transparencyof data with full documentation of experimental procedures,sample preparation, and analysis, and the need for analyticalprocedures to distinguish the origins of NPs.In 2010, a special series of nano papers was published in
Journal of Environmental Quality. Top experts in the field led offthis special issue with a review of the environmental occurrence,behavior, fate, and ecological effects of NPs.29 Within this reviewarticle, there are discussions of risks and release of engineerednanomaterials, key research areas and needs, and sustainabledevelopment of engineered nanomaterials. Important questionsraised include: How much will be released? In which environ-mental compartments will they reside? What are the environ-mentally relevant forms? How do environmental conditionsdetermine the form of nanomaterials?Peralta-Videa et al. also wrote an excellent review on nano-
materials in the environment and summarized work on riskassessment/toxicity, characterization and stability, toxicity, fate,and transport of nanomaterials in terrestrial ecosystems, as wellas new engineered nanomaterials.30 Gottschalk and Nowackpublished a review, which included discussion of life cycleconsiderations of nanomaterials (from production, use in pro-ducts, and recycling/disposal), release scenarios, models topredict their release into the environment, and experimentalmeasurements of nanomaterial release in the environment.31
Nanosilver and Nanogold. Fabrega et al. reviewed thebehavior and effects of silver NPs in the aquatic environment.32
Included is a discussion of the synthesis and characterization ofsilver NPs, their release in the environment, and uptake and effectsin aquatic organisms, including fish. Farkas et al. measured silverNPs released in effluents from a new commercially available silvernanowashing machine.33 This washing machine released silver atan average of 11 μg/L, as measured by ICPMS. The presence ofsilver NPs was confirmed by single particle ICPMS, as well as ionselective electrode measurements and filtration techniques. Theaverage size measured was 60�100 nm, and the effluent wasshown to have an adverse effect on a natural bacterial community.Consumer aerosol sprays were the subject of another study byLorenz et al., who used ICPMS to measure inorganic NPs in anantiperspirant, shoe impregnation sprays, and a plant strengthen-ing agent.34 Nanosized aerosols were observed in products thatcontained propellant gas. Highest levels were found in the anti-perspirant containing nanosilver.
In a newmethod for silver NPs, Poda et al. used flow-field flowfractionation and ICPMS to measure silver NPs in aqueoussuspensions and in biological tissues from aquatic organisms.35
Flow-field flow fractionation produced comparable results toother established sizingmethods, and ICPMS provided increasedsensitivity and selectivity relative to other detection techniques.Laborda used single particle detection with ICPMS in a newmethod to measure nanosilver in aqueous samples.36 Size limitsfor the detection of pure silver NPs were 18 nm, and detectionlimits were 1 � 104 particles/L. In another method, Chao et al.used cloud point extraction and ICPMS to measure silver NPs inantibacterial products and environmental waters.37 Limits ofquantification for antibacterial products were 0.4 μg/kg and0.2 μg/kg for silver NPs and total silver, respectively. Thismethod was then used to measure nanosilver in 6 differentantibacterial products. Interestingly, results revealed NPs in only3 of the 6 tested products, even though all 6 were labeled ascontaining NPs.The first evidence of trophic transfer of NPs from a terrestrial
primary producer to a primary consumer was demonstrated in anew study, along with the first evidence of biomagnification of ananoparticle within a terrestrial food web. In this interesting fate-uptake study, Judy et al. used tobacco plants and tobacco hornworms to investigate plant uptake and the potential for trophictransfer of 5, 10, and 15 nm diameter gold NPs.38 ICPMS, laserablation-ICPMS, and X-ray fluorescence were used for measure-ment of the gold NPs. Results revealed trophic transfer andbiomagnification of the nanogold from the plant to the animal byfactors of 6.2, 11.6, and 9.6 for the 5, 10, and 15 nm-sizedparticles. Due to these findings, the authors highlighted theimportance of considering dietary uptake as a pathway fornanoparticle exposure and also potential issues with long-termland application of biosolids containing NPs.Fullerenes andOther Carbon-BasedNanomaterials. Pycke
reviewed strategies for quantifying C60 fullerenes in environ-mental and biological samples, along with implications forstudies in environmental health and ecotoxicology.39 Theauthors stressed that our ability to quantify fullerenes in biolog-ical samples largely depends on our ability to extract thesecompounds from the complex matrixes, and so far, liquid�liquidextraction is considered the most robust method for fullereneextraction. However, there is a need for automated SPE extrac-tions to improve detection limits for low-level environmentaldeterminations and reduce solvent consumption. In anotherreview, Scida et al. highlighted recent novel applications ofcarbon-based nanomaterials, including their use in sample pre-paration, separation, and detection.40 This included such appli-cations as the extraction of flavonoids, proteins, peptides, andphosphopeptides using SPE with C60 fullerenes bound to silicaparticles; separation of chiral compounds through the use ofcarbon nanotubes coated with β-cyclodextrins; and the applica-tion of carbon nanotubes to the electrochemical detection oforganic compounds.Cosmetics were the focus of another investigation by Benn et al.,
whomeasuredC60 andC70 fullerenes using LC/APCI-MS/MS.41
C60 was detected in four commercial cosmetics (face serums/creams), ranging from 0.04 to 1.1 μg/g, and C70 was qualitativelydetected in two samples. A single use (0.5 g) can contain up to0.6 μg of C60.Hydroxylated fullerenes were the subject of a new LC/MS/
MSmethod developed by Chao et al.42 A hydrophilic interactionliquid chromatography (HILIC) column was used to achieve
good separation of the commercial fullerols, and method detec-tion limits of 0.19 ng/L were achieved. This method was thentested in the presence of Suwannee River fulvic acid (as a modelfor natural organic matter commonly present in environmentalwaters), which significantly interfered with LC/UV measure-ments but only minimally impacted the LC/MS/MS measure-ment. Finally, van Wezel et al. developed an LC/linear ion trap(LTQ)-Orbitrap-MS method for measuring C60 fullerene and itstransformation products in environmental waters.43 This meth-od enabled measurements as low as 5 ng/L and revealed that C60
transformation products can exceed levels of their parent com-pounds in freshly prepared aqueous standards and also instandards stored at room temperature in light for 1�2.5 h.Transformation products resulted from oxidation and could bedetermined with accurate mass measurements. However, no C60
or its transformation products were detected in a wide array ofsurface waters collected in The Netherlands. This was attributedto the possibility of low emissions or losses in the aqueoussolution phase by sedimentation, sorption, or transformation.Nanomaterials in Foods, Plants, and Biota. Determination
of nanomaterials in food was the subject of a review by Blasco andPico.44 This review highlighted current applications of nanoma-terials in foods, food additives, and food-contact materials anddiscussed analytical methods for measuring them. Food matrixesincluded bread, biscuits, fish, and food packaging. In a ground-breaking study, Rico et al. demonstrated the first evidence fordifferential biotransformation and genotoxicity of ZnO andCeO2 NPs in terrestrial plants.45 In this study, ZnO and CeO2
NPs affected the growth of soybean plants. CeO2 NPs werefound in the roots, and ZnO NPs biotransformed. Both weregenotoxic to the soybean plants. In a separate review by Rico et al.,the interaction of NPs with edible plants and their possibleimplications in the food chain were addressed.46 Several studieshave shown effects on seed germination, but few have shownbiotransformation of NPs in food crops. Possible transmission ofNPs and potential biomagnification from edible plants is notknown. Finally, Cassee et al. reviewed the exposure, health, andecological effects of cerium and CeO2NPs associated with its useas a fuel additive.47 CeO2 NPs have been used as an additive indiesel fuels since 1999 to increase mileage by performing as acombustion catalyst, increasing fuel combustion efficiency, anddecreasing diesel soot emissions. However, engine tests haveshown that small amounts of nano-CeO2 can be released inparticulate matter in the exhaust. Ongoing exposure is occurringin large populations, but the impacts to environmental and publichealth are not known.
’PFOA, PFOS, AND OTHER PERFLUORINATEDCOMPOUNDS
Perfluorinated compounds (PFCs) (also referred to as fluoro-telomer-acids, alcohols, and sulfonates) have been manufacturedformore than 50 years and have been used tomake stain repellents(such as polytetrafluoroethylene and Teflon) that are widelyapplied to fabrics and carpets. They are also used in the manu-facture of paints, adhesives, waxes, polishes, metals, electronics,fire-fighting foams, and caulks, as well as grease-proof coatings forfood packaging (e.g., microwave popcorn bags, French fry boxes,hamburger wrappers, etc.). PFCs are unusual chemically, in thatthey are both hydrophobic (repel water) and lipophobic (repellipids/grease), and they contain one of the strongest chemicalbonds (C�F) known. Because of these properties, they are highly
stable in the environment (and in biological samples) and haveunique profiles of distribution in the body. During 2000�2002, anestimated 5 million kg/yr was produced worldwide, with 40% ofthis in North America. Two of these PFCs, perfluorooctanesulfonate (PFOS) and perfluorooctanoic acid (PFOA), havereceived the most attention. PFOS was once used to make thepopular Scotchgard fabric and carpet protector, and since 2002, itis no longer manufactured in the U.S., due to concerns aboutwidespread global distribution in the blood of the general popula-tion and in wildlife, including remote locations in the Arctic andNorth Pacific Oceans. Like PFOS, PFOA is ubiquitous at lowlevels in humans, even in those living far from any obvioussources.1
In January 2005, the U.S. EPA issued a draft risk assessment ofthe potential human health effects associated with exposure toPFOA (www.epa.gov/oppt/pfoa/pubs/pfoarisk.html), and inJanuary 2006, the U.S. EPA invited PFC manufacturers toparticipate in a global stewardship program on PFOA and relatedchemicals (www.epa.gov/oppt/pfoa/pubs/stewardship). Parti-cipating companies agreed to commit to reducing PFOA fromemissions and product content by 95% by 2010 and to worktoward eliminating PFOA in emissions and products by 2015.The U.S. EPA has now listed PFOA and PFOS on the newContaminant Candidate List (CCL-3), a priority list for consid-eration for future regulation in drinking water (http://water.epa.gov/scitech/drinkingwater/dws/ccl/ccl3.cfm). In Europe, theEuropean Food Safety Authority has established tolerable dailyintakes for PFOA and PFOS (www.efsa.europa.eu), and there arenew restrictions on the use of PFOS as part of the EuropeanUnion’s REACH program (http://ec.europa.eu/enterprise/sectors/chemicals/files/reach/restr_inventory_list_pfos_en.pdf).
Potential health concerns include developmental toxicity,cancer, and bioaccumulation. Research questions include under-standing the sources of PFOA and other PFCs, their environ-mental fate and transport, pathways for human exposure anduptake, and potential health effects. It is hypothesized that thewidespread occurrence of PFOA and other fluoro-acids is partlydue to the atmospheric or oceanic transport of the more volatilefluorinated telomer alcohols (FTOHs) and subsequent transfor-mation into PFOA and other fluoro-acids via metabolism andbiodegradation. Recent studies support this hypothesis. In addi-tion, there is evidence that PFOA itself is volatile (can sublime inits solid form) and that it can also partition from water to air.48
Even the ammonium salt form of PFOA can sublime into air. Inaddition to providing another unexpected mechanism for atmo-spheric transport for PFOA, these results also suggest that extracare should be taken in manufacturing facilities that make or usePFOA in formulations in order to minimize workplace exposurefrom inhalation.
PFOS, PFOA, and other PFCs are included in the NationalHealth and Nutrition Examination Survey (NHANES) con-ducted by the Centers for Disease Control and Prevention(CDC) to provide a better assessment of the distribution ofthese chemicals in adults and children in the United States (www.cdc.gov/nchs/nhanes.htm). This survey is carried out on acontinual basis, with blood and urine collected from thousandsof participants in the United States. The most recent reportthat includes population serum levels of PFCs can be foundat www.cdc.gov/exposurereport/pdf/FourthReport.pdf. TheNational Toxicology Program is also studying PFOA and severalother perfluorocarboxylic acids (PFCAs) and perfluorosulfonates(PFSAs) to better understand their toxicity and persistence in
human blood (http://ntp.niehs.nih.gov). Unlike other contami-nants that accumulate in humans (e.g., dioxins, polychlorinatedbiphenyls), PFCs do not accumulate in fatty tissues but bind toserum proteins and accumulate instead in blood. As such, theyhave unique profiles of distribution in the body, owing to theirunique chemical properties.
While PFOS and PFOA were the first fluorinated surfactantsto receive considerable attention, research has rapidly expandedbeyond these two contaminants to other long-chain perfluori-nated acids and various precursors. In addition, there is increasedfocus on shorter-chain forms, e.g., perfluorobutanoic acid (PFBA)and perfluorobutane sulfonate (PFBS), as manufacturers arebeginning to shift to lower molecular weight PFCs that are notbioaccumulative.
Butt et al. published a nice review detailing the levels andtrends for PFCs in the Arctic environment.49 This review detailsmeasurements in snow from various regions of the Arctic, lakewater and sediments, seawater and marine sediments, marineecosystems, freshwater ecosystems, and terrestrial ecosystems.Transport pathways are also discussed. The authors point outthat the detection of PFCAs and PFSAs in snow deposition isconsistent with the volatile precursor hypothesis. Gaps in ourknowledge include lack of knowledge regarding PFCs in theRussian Arctic, lack of measurements in abiotic systems, andlimited measurements in seawater. Pico et al. published a reviewon the global perspective of PFCs in food.50 Food contaminationlevels and dietary intake risks posed by PFCs are outlined, as wellas specific methods for their determination.Measurements in Biota. Studies continue to investigate
PFCs in biota. Thomsen et al. examined changes in PFC levelsin breast milk during 12 months of lactation for 9 mothers livingin Oslo, Norway.51 This study was the first to measure depura-tion rates of PFOS and PFOA from human milk. Significantdecreases in breast milk concentrations per month were ob-served, with depuration rates of 3.8 and 7.8% per month forPFOS and PFOA, respectively. After one year of breast feeding,concentrations were reduced by 37 and 94%, respectively, suchthat lactation was an important route of excretion for mothers.However, infants receive approximately 112 and 61 ng/day, suchthat lactation is a significant source of exposure for them. Humanmilk from China was the focus of another study by Liu et al., whomeasured 10 PFCs in 24 pooled samples from 1237 individualhuman milk samples collected from 12 provinces in China.52
PFOS and PFOA were the dominant PFCs found in all samples,with a mean of 46 pg/mL for each. High levels included 814 pg/mL for mothers living in rural areas and 616 pg/mL for thoseliving in urban settings (e.g., Shanghai). The estimated mean andmaximum dietary intake were 17.8 ng/kg/d and 129.1 ng/kg/d,respectively.In another study by Harada et al., blood serum samples were
collected from women in Japan, Korea, and Vietnam to assessPFOS and PFOA levels since the voluntary phase-out by 3 MCorporation of PFOS in 2002 in the region.53 Serum PFOSlevels ranged from 4.86 ng/mL in Japan to 9.36 ng/mL in Korea(2007�2008). Serum PFOA levels ranged from 0.575 ng/mLin Vietnam to 14.2 ng/mL in Japan. PFOA levels increased inKorea from 1994 to 2008, but PFOS levels did not change.Serum PFOS levels from Japan in 2008 showed significantdecreases (by 22�67%) compared to 2003/2004 levels. PFOAtrends were mixed, as one highly exposed area of Japan showeda clear decline from 2003 to 2008, but low-exposure areasshowed no change.
Freberg et al. reported a fascinating human exposure studyinvolving professional ski waxers from two national winter sportsteams participating in the World Cup.54 Perfluorinated alkanesare used with petroleum-derived straight-chain aliphatic hydro-carbons in ski waxing products, and ski waxes are widely used byski teams to increase performance. The product is applied eitherthrough the use of solid blocks, which are melted and drippedonto the ski using a heated iron, or through the use of powders,both of which are heated with an iron to create a smooth surface.During this process, significant aerosols can be generated,creating a risk for inhalation of PFCs. This human exposurestudy involved themeasurement of 11 PFCAs and 8 PFSAs in theserum of 13 professional ski wax technicians. Highest medianlevels were for PFOA (50 ng/mL), which were 25� higher thanbackground levels. Perfluorotetradecanoic acid was also reportedfor the first time in human serum. Positive, statistically significantassociations were observed for years exposed as a ski waxer and 7PFCAs in human serum. During an 8-month interval where noexposures were occurring, C8�C11 PFCAs decreased by 5�20%.This study was the first to link PFCAs in ski waxers’ serum toexposure from work room aerosols. In a related study fromSweden, Nilsson et al. investigated inhalation exposure to PFCsin air collected from the breathing zone of ski wax techniciansduring work.55 Air samples were collected with cartridges con-nected to portable air pumps. PFCAs were measured using LC/MS/MS, and FTOHs (6:2, 8:2, and 10:2) were measuring usingGC/MS/MS. Daily inhalation exposures of 8:2 FTOH were800� higher than for PFOA. Overall levels ranged from 830 to255 000 ng/m3. Together with other results showing increasedlevels of PFOA in blood serum, these results suggest thebiotransformation of 8:2 FTOH to PFOA.PFCs in bird eggs were the focus of two recent studies. In the
first, Holmstrom et al. investigated the temporal trends of PFCs inSwedish Peregrine falcon eggs from 1974 to 2007.56 This was thefirst study to establish temporal trends for PFCs in terrestrial biota.PFCAs, PFSAs, and perfluorooctane sulfonamide (PFOSA) weremeasured. PFOS was predominant (83 ng/g wet weight insamples from 2006), followed by perfluorotridecanoic acid(PFTrA) (7.2 ng/g wet weight) and perfluoroundecanoic acid(PFUnA) (4.2 ng/g wet weight). PFCA concentrations increasedexponentially over time, whereas PFOS and PFHxS leveled offafter the mid-1980s. In the second study, Gebbink et al. measuredlinear and branched PFOS isomer patterns in herring gull eggsfrom bird colonies in different regions of the Great Lakes (U.S.).57
Eggs were collected in 2007 from 15 bird colonies, and linearPFOS was consistently the dominant isomer in all eggs, compris-ing 95�98% of the total PFOS isomers. Linear PFOS wasenriched in the gull eggs relative to technical PFOS, and higherproportions were observed in eggs from the lower lakes (Lake Erieand Lake Ontario).Fernandez-Sanjuan et al. used a solid�liquid extraction-LC/
MS/MS method to evaluate the occurrence of PFOS, PFOA,perfluorononanoic acid (PFNA), PFHxS, and PFBS in aquaticorganisms.58 Freshwater organisms were studied along with thosefrom marine ecosystems and included insect larvae, oysters, zebramussels, sardines, and crabs. Among the organisms studied, noneof the bivalves accumulated PFCs, but instead, insect larvaecontained the highest levels, followed by fish and crabs, rangingfrom 0.23 to 144 ng/g wet weight for PFOS and 0.14 to 4.3 ng/gwet weight for PFOA, with only traces of PFNA and PFHxS. PFBSwas not detected in any of the organisms. Fish were the focus ofanother occurrence study published by Schuetze et al.59 Wild fish
(including eels) were caught from different rivers in NorthernGermany, as well as from the North Sea and Baltic Sea. PFOA wasnot found in any of the fish filet samples above the quantificationlimit of 0.27 μg/kg (fresh weight), whereas PFOSwas detected upto 225 μg/kg (fresh weight), particularly from densely populatedareas. Marine samples and samples from remote locations showedfewer positive detections, with a maximum to 50.8 μg/kg. On thebasis of a provisional tolerable daily intake proposed by theEuropean Food Safety Authority, 33 of the 112 fish samples mightbe classified as a potential risk for consumers with high fishconsumption.Paper Coatings for Food Packaging.Trier et al. explored the
identity of PFCs used for food contact materials used to impartoil and water repellency.60 Information was combined frompatents, chemical suppliers, and analyses of industrial blends(using UPLC/MS/MS). More than 115 compounds were foundin industrial blends from the European Union, U.S., and China.PFCs identified included polyfluoroalkyl-mono- and diesterphosphates (monoPAPS, diPAPS, and S-diPAPS), -ethoxylates,-acrylates, -amino acids, -sulfonamide phosphates, and -thioacids, together with residuals and synthesis byproducts. In addi-tion, a large number of starting materials, such as perfluorooctanesulfonamide N-alkyl esters, were analyzed. Fourteen differentproducts were then tested for PFC migration, including micro-wave popcorn (from 6 manufacturers), a hamburger box, cho-colate cake mix, bread mix, prepackaged frozen dinners, noodles,and coffee cups. Standardized migration testing used for plastics(60 �C, 2 h test, 1 dm2) was used to evaluate potential migrationfrom the coated paper/cardboard packaging. Of the 14 samples,diPAPS and S-diPAPS were detected in 5 and 4 food migratesamples, respectively, with highest levels from microwave pop-corn bags, up to 0.7 mg/kg. Besides microwave popcorn, the onlyother product that showed migration was a hamburger box, butlevels were much lower. While PFOS and its derivatives are nowprohibited for manufacture in the U.S. and in Europe, thesederivatives were still present in the food packaging for theseproducts sold in the U.S. and Europe. Because diPAPS are knownto metabolize to PFCAs, the authors suggest that more types ofPFCs should be monitored in order to map the sources inhumans and the environment.Drinking Water. Thompson et al. conducted an extensive
drinking water occurrence study from 34 locations acrossAustralia, including capital cities and regional centers.61 SPEwith LC/MS/MSwas used for measurement, and a wide range ofPFCs were measured. PFOS and PFOA were the most com-monly detected, present in 49 and 44% of the samples, respec-tively. PFOS was found at the highest level, up to 16 ng/L, withPFHxS and PFOA up to 13 and 9.7 ng/L, respectively. Thecontribution from drinking water for PFOS and PFOA was2�3%, with a maximum of 22 and 24%, respectively.Landfill Leachates. Because many PFC-containing products
(paper packaging, nonstick coated pans, etc.) are disposed of inmunicipal landfills, there is a concern regarding PFCs leachinginto groundwater and surface waters. Landfill leachates were thefocus of two new studies. Busch et al. measured 43 PFCs in 22landfill sites in Germany.62 Total PFC concentrations rangedfrom 31 to 12 819 ng/L in untreated leachate and from 4 to 8060ng/L in treated leachate. Dominant compounds were PFBA andPFBS. PFC discharges varied according to the type of treatmentused. Membrane treatment (reverse osmosis and nanofiltration)and activated carbon released the lowest concentrations into theenvironment than those using wet air oxidation or only biological
treatment. Mass flows of total PFCs ranged from 0.08 to 956mg/day. Another landfill leachate study by Huset et al. used SPE withdispersive carbon sorbent cleanup and LC/MS/MS to measure24 PFCs in landfill leachates from 4 locations in the U.S.63 Inaddition, leachate generated in a laboratory bioreactor containingresidential refuse was investigated. All 7 leachates showed higherlevels of short-chain PFCAs or PFSAs (C4�C7) as compared tolonger-chain homologues (gC8). PFCAs were the most abun-dant, followed by the PFSAs, with PFBS levels up to 2300 ng/L.Sulfonamide derivatives were also observed, at ∼8% of the totalPFCs measured.Seawater and Sediments. The distribution of PFCs in sea-
water from the North Sea and the Baltic Sea was the focus of astudy by Theobald et al.64 Observed gradients could be explainedby oceanographic mixing processes and currents, with large riversas major sources. For example, 9 ng/L PFOA and 8 ng/L PFOSwere found at the mouth of the river Elbe, but concentrationsdecreased to 3.8 and 1.8 ng/L, respectively, along the coast, anddropped to 0.13 and 0.09 ng/L, respectively, toward the open sea.Along the Dutch coast, high PFBS levels (3.9 ng/L) wereobserved. In the Baltic Sea, even distributions of PFCs wereobserved, with PFOA and PFOS predominant. In another study,Zushi et al. investigated time trends of PFCs from sediment corestaken from Tokyo Bay, Japan from the 1950s until 2004.65 Theauthors demonstrated that sediment cores can serve as a tool forreconstructing past PFC contamination and provided evidenceon their environmental dynamics and time trends. Concentra-tions of 24 PFCs were measured. PFOS decreased gradually fromthe early 1990s, and its precursors, N-ethyl perfluorooctanesulfonamide acetate (N-EtFOSAA) and N-methyl perfluorooc-tane sulfonamide acetate (N-MeFOSAA), decreased rapidly inthe late 1990s, whereas PFOA increased rapidly. Observed trendsrevealed a shift from perfluorooctyl sulfonyl fluoride (PFOSF)-based product to telomer-based products after the phase-out ofPFOSF-based products in 2001.Air and Soils around a Fluorochemical Manufacturing
Plant. An interesting study by Ruan et al. investigated thepresence and partitioning behavior of polyfluorinated iodides(PFIs) in environmental matrixes around a fluorochemicalmanufacturing plant in China.66 This study confirmed thepresence of 4 perfluorinated iodine alkanes (FIAs) and 3 poly-fluorinated telomer iodides (FTIs) in the environment. Thermaldesorption-GC/high resolution-MS was used for air measure-ments, and a SPME-GC/low resolution-MSmethod was used forsoil. Ambient air collected around the plant showed a wideconcentration range, from 1.4 to 3.08 � 104 pg/L for FIAs and1.39 to 1.32 � 103 pg/L for FTIs. In surrounding soils, most ofthe PFIs were not detected, with only a few higher carbon-chainanalytes sporadically detected, up to 499 pg/g. Measurementssuggest unintentional release of PFIs during the telomer-basedmanufacturing process. Because a majority of the PFIs partitionto the gas phase, it is likely that these PFCs are transportedatmospherically. In addition, PFIs have the potential to beconverted into PFCAs. Because perfluorooctane iodide was alsodetected in fluorotelomer raw materials at high ppm levels, theseother PFC sources should be investigated further.Sewage Sludge. Sun et al. developed a method based on
solvent extraction and LC/MS/MS to measure long-chain PFCsin digested sewage sludge from Switzerland.67 Total PFCAsranged from 14 to 50 μg/kg dry matter, and PFOS ranged from15 to 600 μg/kg. In three wastewater treatment plants, PFOSlevels were 6�9� higher than those from other plants. Because
the elevated PFOS levels did not correlate with higher levels ofPFCAs, different local sources were suggested.New PFC Substitutes. As mentioned earlier, due to the
phase-out of PFOS and PFOA, there has been a transition inmanufacturing toward shorter-chain PFCs that are not bio-accumulative or are more biodegradable. Quinete et al. recentlyinvestigated the degradability of 5 new perfluorinated surfac-tants: PFBS, fluorosurfactant Zonyl (a fluorinated alkyl ether),two fluoroaliphatic esters (NOVEC FC-4430 and NOVEC FC-4432), and 10-(trifluoromethoxy)decane-1-sulfonate using ad-vanced oxidation based on UV, hydrogen peroxide, or combina-tions, followed by more conventional biodegradability tests,including a fixed-bed bioreactor, biological oxygen demand,and the closed-bottle test with microorganisms from the RhineRiver.68 Most of these fluorinated surfactants are well establishedin the marketplace and have been used in applications asalternatives to PFOS- and PFOA-based surfactants. LC/MS/MS was used to measure the degradation of the parent PFCs.Results showed that PFBS is not biodegradable. However, micro-organisms could degrade 10-(trifluoromethoxy)decane-1-sulfo-nate in 6 days. The fluoroaliphatic ether and esters degradedslowly and did not meet the criterion for ready biodegradation.PFBS degradation by UV and oxidation was not significant within120 min; other PFCs degraded upon exposure to UV, especiallywhen coupled with hydrogen peroxide. In another study, Arakakiet al. investigated themicrobial degradation of a new fluorotelomeralcohol, 1H,1H,2H,2H,8H,8H-perfluorododecanol.69 A mixedbacterial culture obtained from activated sludge was used to testfor biological degradation, and LC/MS was used to analyzemetabolites. PFBA, perfluoropentanoic acid, and perfluoropenta-nedioic acid were found as degradation products. The parentperfluorinated surfactant was cleaved into two short-chain fluori-nated carboxylic acids that have less bioaccumulative potential andlower toxicity that the biodegradation products of 8:2 FTOH.Fate and Sources. Lee et al. investigated the biodegradation
of polyfluoroalkylphosphates (PAPs) as a source of PFCAs to theenvironment.70 Headspace sampling revealed production of thefluorotelomer alcohols (FTOHs) from the hydrolysis of the PAPphosphate ester linkages. Analysis of the aqueous phase revealedmicrobial transformation to the final PFCA products. Mostproducts were consistent with beta-oxidation-like mechanisms,but the detection of odd-chain PFCAs suggested that otherpathways are likely. Results suggest that PAP-containing com-mercial products may be a significant contributor to the increasedPFCA mass flows observed in wastewater treatment effluents.Fr€omel and Knepper examined the biotransformation of fluoro-telomer ethoxylates (FTEOs) as sources of PFCs in the environ-ment.71 The fluorotelomer ethoxylates are high productionchemicals but have not been seriously considered as potentialsources of PFCs in the environment. Experiments showed thatthe FTEOs are aerobically degraded, with a half-life of 1 d.Structural elucidation of the transformation products was madeusing LC/ESI-MS/MS, and a pathway was proposed. In addi-tion to short-chain FTEO carboxylates, perfluorohexanoic acid(PFHxA) and PFOA were detected but were likely formed bydegradation of residual fluorotelomer alcohols present in thecommercial product.Sea spray was investigated in another study byWebster and Ellis
as a means of generation of PFCAs into the gas phase.72 Usingobserved concentrations of perfluorooctanoate in oceans of theNorthern Hemisphere and estimated spray generation rates, thismechanism was shown to have potential for contributing large
amounts of PFOA to the atmosphere and may contribute to theconcentrations observed in remote locations.Thompson et al. examined the fate of PFSAs and PFCAs in
two water reclamation plants in Australia.73 One plant usesadsorption and filtration with ozonation, and the second usesmembrane processes and advanced oxidation to produce purifiedrecycled water from treated wastewater. Concentrations of PFOSand PFOA were reduced somewhat after treatment with ozone,and all PFCs were removed in the finished water by reverseosmosis.New Methods. New methods continue to be developed for
PFCs. Gosetti et al. developed an automated online SPE-UPLC/MS/MS method for measuring 9 PFCs in biological, environ-mental, and food samples.74 Limits of detection ranged from 3 to15 ng/L, and the method was used to measure PFCs in riverwater, blood serum, blood plasma, and fish. Chromatographicseparations could bemade in 7min. Lacina created a newUPLC/MS/MS method for measuring 23 PFCs in milk and fish.75
Limits of quantification were 1�6 ng/L and 2�13 ng/L for milkand fish, respectively. This method was then used to measurePFCs in milk and canned fish samples, which revealed a widespectrum of PFCAs, PFOS, and perfluoro-1-octanesulfonamide(PFOSA) in canned fish.Umbilical cord blood was the focus of a new UPLC/MS/MS
method by Lien et al.76 This method allowed limits of quantifica-tion of 0.15 to 3.1 ng/mL for 12 PFCs. PFOA, PFOS, PFUnA,and PFNAwere then detected in 68% of umbilical cord plasma insamples from the Taiwan Birth Panel Study. Beser developed amicrowave-assisted extraction-LC/MS/MS method to measure12 per- and polyfluorinated compounds in airborne particulatematter.77 Recoveries ranged from 83 to 120%, and quantificationlimits of 1.4 pg/m3 were achieved. This method was then used tomeasure PFCs in air samples collected in Valencia, Spain. Eight ofthe 12 PFCs were quantified in at least one sample, with levelsranging from 1.4 to 34.3 pg/m3.Llorca et al. used pressurized solvent extraction with LC/MS/
MS in a method to measure 13 PFCAs, 4 PFSAs, and perfluoro-octane sulfonamide in sewage sludge.78 Method detection limitsof 15 to 79 ng/kg were achieved, and the method was sub-sequently used to measure PFCs in 5 different sludge samples.Results showed all 18 PFCs present in all sludge samples, butmany were below the limit of quantification. PFOSwas present atthe highest level, up to 121 μg/kg.Matrix-assisted laser desorption ionization (MALDI)-TOF-
MS was used in a new method by Cao et al. to measure PFCs inenvironmental waters.79 In this method, 1,8-bis(tetramethyl-guanidino)-naphthalene was used as the matrix, and SPE wasused for preconcentration of PFCs. Very low limits of detectionof 0.015 ng/L for PFOS were obtained, which were lower thanLC/MS/MS methods. Finally, Sun et al. used derivatization withbenzylamine and LC/MS in a new method to measure perfluor-ooctane sulfonyl fluoride (PFOSF) in environmental samples.80
Detection limits of 2.5 pg were possible, and the derivatizationwas selective for PFOSF.
’PHARMACEUTICALS AND HORMONES
Pharmaceuticals and hormones have become important emerg-ing contaminants, due to their presence in environmentalwaters (following incomplete removal in wastewater treatmentor point-source contaminations), threat to drinking water, andconcern about possible estrogenic and other effects, both to
wildlife and humans. A major concern for pharmaceuticals alsoincludes the development of bacterial resistance (creation of“Super Bugs”) from the release of antibiotics to the environment,and there are also new concerns that antibiotics will decreasebiodegradation of leaf and other plant materials, which serves asthe primary food source for aquatic life in rivers and streams. It isestimated that approximately 3200 different substances are usedas pharmaceutical ingredients, including painkillers, antibiotics,antidiabetics, betablockers, contraceptives, lipid regulators, anti-depressants, chemotherapy drugs, and impotence drugs. How-ever, only a very small subset of these compounds has beeninvestigated in environmental studies so far. Pharmaceuticalsare introduced not only by humans but also through veterinaryuse for livestock, poultry, and fish farming. Various drugs arecommonly given to farm animals to prevent illness and diseaseand to increase the size of the animals. One lingering question iswhether the relative low environmental concentration levels ofpharmaceuticals (generally ng/L range) would cause adverseeffects in humans or wildlife. Pharmaceuticals and hormones arenow included on the U.S. EPA’s final CCL-3 (http://water.epa.gov/scitech/drinkingwater/dws/ccl/ccl3.cfm). One antibiotic(erythromycin) and one explosive (nitroglycerin) that is alsoused as pharmaceutical and 8 natural and synthetic hormones(17α-ethinylestradiol [EE2], 17α-estradiol, 17β-estradiol [E2],equilenin, equilin, estriol [E3], estrone, mestranol, andnorethindrone) are included as priority drinking water contami-nants, on the basis of health effects and occurrence in environ-mental waters. For the revision of the priority substances listwithin the EU water framework directive (2000) describing thechemical status of European rivers, streams, and lakes, twopharmaceuticals (diclofenac and ibuprofen) and two hormones(EE2 and E2) are suggested. There are also increasing “source-to-tap” studies considering the fate of pharmaceuticals fromwastewaters to river waters, to source waters, and to finisheddrinking water, such that the complete cycle of pharmaceuticalfate is being considered.
Innovative analytical instrumentation, such as hybrid massspectrometry, enables the identification and quantification oforganic pollutants, including pharmaceuticals and hormones,down to the lower ng/L and ng/kg range in environmentalmatrixes and drinking water. While most organic contaminantsenter wastewater without being metabolized, pharmaceuticals arefrequently transformed in the body and a combination of non-altered pharmaceuticals and their metabolites are excreted byhumans. Microbial transformation products (TPs) of pharmaceu-ticals and hormones can be formed during biological wastewatertreatment, from contact with sediment and soil, as well as duringbank filtration. Furthermore, TPs can be formed byUV irradiationin surface waters and during oxidative treatment processes, such asozonation and chlorine disinfection. Still, LC/MS/MS is themethod of choice for the determination of all classes of pharma-ceuticals in aqueous matrixes. ESI and APCI are the mostcommonly used LC interfaces. Major innovations have beenmadeinmodern hybridmass spectrometry systems (e.g., linear ion trap/FT-MS, Q-TOF-MS) coupled to liquid chromatography, provid-ing accurate masses of the analytes and information for massfragments, which can be used to identify the chemical structures.Further innovations have beenmade in rapid online extraction andbag extraction, as well as online derivatization techniques incombination with GC/MS(/MS) detection.Environmental Impacts of Pharmaceuticals. Research on
pharmaceuticals continues to grow exponentially, and this is
again evidenced by the vast number of reviews published the last2 years, as well as the number of special issues of journalscovering them. While many pharmaceuticals can have an acuteor chronic effect on aquatic or other organisms, most of thelowest observed effect concentrations (LOECs) are substantiallyabove the environmental concentrations that have been observed(ng/L to low μg/L). However, there are a few notable excep-tions, where chronic toxicity LOECs approach levels observed inwastewater effluents. For chronic toxicity, these include salicylicacid, diclofenac, propranolol, clofibric acid, carbamazepine, andfluoxetine. For example, for diclofenac, the LOEC for fish toxicitywas in the range of wastewater concentrations, and the LOEC ofpropranolol and fluoxetine for zooplankton and benthic organ-isms was near the maximum measured in wastewater effluents.The antibiotic ciprofloxacin has also been shown to have effectson plankton and algae growth at environmentally relevantconcentrations.1 Estrogenic effects on wildlife are quite possiblewith the contraceptive α-ethinylestradiol (EE2), as it can induceestrogenic effects in fish at extremely low concentrations (lowand sub-ng/L). Effects include alteration of sex ratios and sexualcharacteristics and decreased egg fertilization in fish.1 An articlein Nature (Oaks, J. L.; Gilbert, M.; Virani, M. Z.; Watson, R. T.;Meteyer, C. U.; Rideout, B. A.; Shivaprasad, H. L.; Ahmed, S.;Chaudhry, M. J. I.; Arshad, M.; Mahmood, S.; Ali, A.; Khan, A. A.Nature 2004, 427, 630�633) highlighted that residues of veter-inary used diclofenac probably caused renal failure of vulturesand hence lead to a dramatic decline (>95%) of the vulturepopulation in India and Pakistan. Experts estimate the vultureloss at 40 million, and it is being called the “worst case of wildlifepoisoning ever”, far eclipsing the numbers of birds affected byDDT a few decades ago. Reviews were published the last 2 yearssummarizing ecotoxicity to aquatic organisms. For example,Santos et al. presented a nice comprehensive listing and discus-sion of many pharmaceuticals from different classes, includingknown ecotoxicity data for the parent drugs as well as metabolitesand environmental transformation products.81 Reported con-centration ranges in the environment were also included. Cor-coran et al. presented a review on the presence and reportedbiological effects of pharmaceuticals in fish.82
General Reviews. A thought-provoking critical review by Ortet al. raised the question: “Sampling for pharmaceuticals andpersonal care products (PPCPs) and illicit drugs in wastewatersystems: are your conclusions valid?”83 Issues discussed includedthe importance of short-term pollutant variations and whetherreported variations can be attributed to real variations or if theysimply reflect sampling artifacts. In another review, Howard andMuir identified commercial pharmaceuticals that might bepersistent and bioaccumulative and were not being consideredin current wastewater and environmental measurement studies.84
Two models, KOWWIN and BIOWIN1/BIOWIN5 (from EPISuite software) were used to predict their potential bioaccumula-tive ability and persistence. A database of 3193 pharmaceuticals wasdeveloped from twoU.S. Food &Drug Administration databasesand lists of top-selling drugs. Of the 3193 pharmaceuticals, 275have been found in the environment, and 92 of these were ratedas potentially bioaccumulative, 121 as potentially persistent, and99 as high production volume (HPV) pharmaceuticals. Otherthan these 275 pharmaceuticals, 58 HPV compounds wereidentified that were both persistent and bioaccumulative, and48 others were identified as persistent only. Of the non-HPVcompounds, 364 were identified as persistent and bioaccumula-tive. As a result, the authors highlighted several pharmaceuticals
that should be considered for future environmental studies. Adetailed listing of these compounds was provided.In a mass spectrometry-focused review, Niessen detailed the
fragmentation of toxicologically relevant drugs in positive-ionLC/MS/MS.85 The MS/MS spectra for ∼570 compounds wasinterpreted, and fragmentation was discussed. Fatta-Kassinoset al. presented a review of pharmaceuticals in environmentalwaters andwastewater.86 Occurrence of many pharmaceuticals ofdifferent classes is discussed, with concentration ranges given, aswell as the ability of different treatment technologies to removethem. The occurrence, transformation, and fate of antibiotics inmunicipal wastewater treatment plants was reviewed by Zhangand Li.87 Major removal pathways included adsorption, biode-gradation, disinfection, and membrane separation, and themajority of antibiotics are only partially eliminated in wastewatertreatment. Daughton published a review on pharmaceuticalingredients in drinking water and discussed their occurrenceand significance for human exposure.88 The 6 pharmaceuticalswith the highest consistently reported concentrations were:ibuprofen, triclosan, carbamazepine, phenazone, clofibric acid,and acetaminophen (paracetamol). Except for ibuprofen and itsmethyl ester metabolite, all of these pharmaceuticals were <1 μg/L. Transformation products and disinfection byproducts are alsooutlined in this review.Illicit drugs have received a great deal of attention since they
were reported in the environment first by Jones-Lepp of the U.S.EPA (2004) and then by Castiglioni et al. from the Mario NegriInstitute in Milan, Italy (2006). A new book on illicit drugs in theenvironment has just been published by Castiglioni et al.89
This book features informative chapters authored by manyresearchers from the U.S. and Europe who are active in this area.Chapters cover environmental occurrence (wastewater, riverwater, groundwater, drinking water, air, and particulate matter)in several countries, analytical methods for measuring illicitdrugs, implications for ecotoxicology, and the use of massspectrometry as a tool to track drug use patterns.Chemotherapy drugs are starting to gain attention in environ-
mental studies, and Kosjik and Heath published a nice review ontheir occurrence, fate, and determination.90 These drugs aregenerally not biodegradable and are designed to be particularlypotent, such that they damage DNA, inhibit DNA synthesis, andinterrupt cell replication. As a result, the potential for ecologicaleffects is real, although the consumption of cytostatic drugs is lowcompared to other pharmaceutical classes.The fate of antibiotics in recycled water was the focus of
another review by Le-Minh et al.91 Advanced treatment pro-cesses included ozonation, chlorination, UV irradiation, activatedcarbon adsorption, and nanofiltration/reverse osmosis filtration.Finally, de Witte et al. reviewed analytical methodologies todetect advanced oxidation products of pharmaceuticals.92
New Methods. Helbling et al. developed a complementarytarget�nontarget procedure for high-throughput elucidation ofTP structures for a diverse group of pharmaceutical andpesticides.93 Pharmaceuticals and pesticides were spiked intobatch reactors seeded with activated sludge, and TPs wereanalyzed using LC/linear ion trap-Orbitrap-MS/MS. CandidateTPs were initially identified using an innovative postacquisitionprocessing method based on target and nontarget screening offull-scan MS data. Using this new method, structures wereproposed for previously unreported microbial TPs for bezafi-brate, diazepam, levetiracetam, oseltamivir, and valsartan. Garcia-Lor published a rapid, multiclass UPLC/MS/MS method for
measuring 47 pharmaceuticals in environmental water andwastewater.94 Pharmaceuticals included analgesic, anti-inflam-matory, and cholesterol-lowering statin drugs, lipid regulators,antidepressants, antiulcer agents, psychiatric drugs, tranquilizers,cardiovasculars, and 26 different antibiotics from differentchemical classes. From a single injection, all analytes could bedetermined in only 10 min.Illicit DrugMethods. Several new methods have been created
the last 2 years for measuring illicit drugs in environmentalsamples. For example, Baker and Kasprzyk-Hordern created aSPE-UPLC/ESI-MS/MS method for measuring 65 stimulants,opium and morphine derivatives, benzodiazepines, antidepres-sants, dissociative anesthetics, drug precursors, human urineindicators, and their metabolites in wastewater and surfacewater.95 All compounds could be separated in ∼23 min, andmethod detection limits ranged from 0.1 ng/L (e.g., cocaine,benzoylecgonine, norbenzoylecgonine, 2-oxo-3-hydroxy-LSD)to 100 ng/L (e.g., caffeine). This method was then used tomeasure the illicit drugs in wastewater and river water from theUK, where 36 of the 65 analytes were detected in river water.Fontanals et al. published a fully automated, online SPE-LC/MS/MS method using HILIC for illicit drugs and other polardrugs in environmental waters.96 Using this method, up to 10mLof environmental waters could be analyzed for low ng/L detec-tion of analytes. The method also yielded ∼100% recoveries.Enantiomeric analysis of illicit and other drugs was made
possible in a method by Kasprzyk-Hordern et al., who used chiralchromatography with SPE-LC/MS/MS to measure structur-ally related amphetamines (amphetamine, methamphetamine,4-methylene dioxymethamphetamine [MDMA], 3,4-methylenedioxyamphetamine [MDA], and 3,4-methylenedioxy-N-ethyl-amphetamine [MDEA]), ephedrines (ephedrine, pseudoephed-rine, and norephedrine), and venlafaxine in wastewater.97 Achiral-CBH UPLC column was used for separations underisocratic conditions. The measurement of enantiomeric fractionsof these chiral drugs showed that they had variable, nonracemiccomposition, and analysis of treated wastewater revealed enan-tioselective processes.GC/MS/MS is still used occasionally for measuring drugs in
environmental samples, often in combination with derivatizationprocesses. For example, Gonzalez-Marino created a SPE-GC/iontrap-MS/MS method for measuring illicit drugs and theirmetabolites in wastewater and surface waters, using N-methyl-N-(trimethylsilyl)trifluoroacetamide (MSTFA) derivatization.98
Limits of detection ranged from 0.8 to 15 ng/L.Marine SampleMethods.Marine sea salts and seawater were
the focus of anothermethod by Serrano et al., who used GC/highresolution-TOF-MS for nontarget screening of organic contami-nants, including compounds used in pharmaceutical and perso-nal care product formulations.99 After dissolving samples inwater, SPE was used to achieve a 250-preconcentration factor.This method allowed detection of contaminants without pre-selection of target pollutants, through the use of accurate-massmeasurements and matching of full-scan spectra with theoreticalMS libraries. This method allowed the identification of manydifferent kinds of contaminants in seawater and marine saltsobtained from solar saltworks and from a pristine sea shoresaltmarsh along the Spanish Western Mediterranean coast. Willeet al. developed a LC/MS/MS method to quantify 13 multiclasspharmaceuticals in seawater.100 Limits of quantification rangedfrom 1 to 50 ng/L, and the method was used tomeasure seawaterand estuarine water samples collected along the Belgian coast.
Using this method, seven pharmaceuticals that had not beenpreviously reported in marine environments were detected, withsalicylic acid and carbamazepine being the most predominant, upto 855 ng/L.Biota Methods. Interesting methods continue to be devel-
oped formeasurement of pharmaceuticals in biota, including fish,shrimp, and mussels. Zhang et al. systematically investigatedmatrix effects observed with the SPME-LC/ESI-MS/MS analysisof fish tissues (fish muscle, brain tissue, blood, and bile) andenvironmental waters (tap water, surface water, wastewaterinfluent/effluents) and were able to offer an improved methodthat corrected for these matrix effects.101 Both enhancementand suppression of ionization were observed with biological andenvironmental samples, and the use of isotopically labeledinternal standards allowed a more accurate quantification ofpharmaceuticals in these types of samples. Unlike a previousisotope dilution approach that added isotopically labeled stan-dards before SPME extraction, this method adds these standardsto the final sample extracts, which simplifies the approach andstill compensates for matrix effects. Li and Kiljak published a newmulticlass, multiresidue LC/MS/MS method for measuring21 veterinary drugs in shrimp.102 Matrix-matched standards wereused for external calibration, except for oxytetracycline, tetra-cycline, norfloxacin, and ciprofloxacin, where an isotopicallylabeled internal standard was used.Wille et al. published a new method using UPLC/MS/MS
for quantifying 11 pharmaceuticals and 14 pesticides in bluemussels.103 Pressurized liquid extraction was used to extract theanalytes from the mussel tissues; limits of quantification rangedfrom 0.1 to 10 ng/g, with good recoveries (90�106%). Usingthis method, 5 pharmaceuticals were found in mussels col-lected from the Belgium coast, with salicylic acid and paracetamol(acetaminophen) found at the highest levels, up to 288 ng/g(dry weight).While this might be considered more of a veterinary method
than for environmental biota, the following paper is worthmentioning. Hamscher et al. developed and validated a LC/ESI-MS/MS method for measuring chemotherapy drugs in dogurine.104 As mentioned earlier, chemotherapy drugs are by theirvery nature extremely toxic and teratogenic, and the introductionof these drugs through animals to the environment has not beenfully appreciated in the scientific literature yet. With improveddiagnostics and medical treatment, chemotherapy drugs havebeen increasingly used for pets (dogs and cats) to treat cancer,and these drugs are excreted in their urine, which can then serveas a source of exposure for the environment, as well as to the petowners and veterinary doctors and technicians. The cytostaticdrugs, vincristine, vinblastine, cyclophosphamide, and doxorubi-cin, were included for this new method, which was tested onurine collected from dogs with lymphoma or mast cell tumorsthat were being treated with chemotherapy drugs. This alsoserved as the first clinical study to investigate concentrations ofcytostatic drugs in canine body fluids. Limits of detection rangedfrom 0.25 to 0.5 μg/L, and the method demonstrated that allinvestigated drugs were found in the urine of dogs undergoingchemotherapy. In samples from day 1, as much as 63 μg/Lvincristine, 111 μg/L vinblastine, and 762 μg/L doxorubicincould be detected. Cyclophosphamide showed only minorconcentrations on day 1 but up to 2583 μg/L directly afterchemotherapy. Consequently, these results indicate that chemo-therapy drugs used by pets might be a potential for environ-mental contamination not previously considered.
Direct Analysis and Novel Approaches. Two methods weresingled out for their use of new, cutting edge techniques. Beissmanet al. used direct analysis in real time (DART) to analyze forpharmaceuticals directly in river water and treated wastewaterextracts.105 Ionization suppression was shown to be <11% formost analytes, which was similar or better than other ESI, APCI,and APPI methods. In another novel method by Moliner-Martinez et al., silica-supported Fe3O4 magnetic NPs were usedto extract and preconcentrate acetylsalicylic acid, acetamino-phen, diclofenac, and ibuprofen from environmental waters.106
Samples were subsequently analyzed by LC/MS. The use of themagnetic NPs enabled concentration factors of 100 and detec-tion limits of 50�150 ng/L, and they could be reused 20 timeswithout loss in extraction efficiency. Recoveries ranged from80 to 110%.Occurrence Studies. Loos et al. reported the first pan-
European survey of the occurrence of polar organic persistentcompounds, including pharmaceuticals, in European ground-water from 23 countries.107 Carbamazepine was the only phar-maceutical present above the quality standard for pesticides ingroundwater of 0.1 μg/L.Several studies have also reported the occurrence of new
drugs. For example, new antiviral drugs were the focus of anewmethod and occurrence study by Prasse et al., who used LC/ESI-MS/MS to measure acyclovir, abacavir, lamivudine, nevira-pine, oseltamivir, penciclovir, ribavirin, stavudine, zidovudine,and one active metabolite in wastewater and surface waters.108
A significant reduction in concentration was observed foracyclovir, lamivudine, and abacavir in treated wastewater. Con-centrations in river water ranged from low ng/L to 190 ng/L (foracyclovir). The ratios of oseltamivir to its metabolite, oseltamivircarboxylate, were approximately 10� higher for the Rhine Rivervs other German rivers, which indicated a significant contribu-tion from other sources, such asmanufacturing discharges. Ferrerand Thurman reported the discovery of a new antidepressant andits glucuronide metabolite in environmental waters.109 For thiswork, a new chlorine mass filter technique used with accuratemass, and high resolution-MS aided in the identification oflamotrigine in wastewater and drinking water. Lamotrigine is arelatively new drug used for the treatment of epilepsy and type Ibipolar syndrome. This was also the first report of a glucuronideof an antidepressant surviving wastewater treatment and becom-ing a groundwater and surface water contaminant.Two interesting occurrence studies investigated drugs at
locations not previously investigated: a fitness center and aprison. In the first study, Schroder et al. measured anabolicsteroids, doping drugs, and “lifestyle” illicit drugs for the first timein wastewater from a fitness center, as well as the sewagetreatment plant influent and effluents.110 SPE with LC/highresolution-MS and LC/MS/MS methods achieved quantifica-tion limits of 5 ng/L. Results showed testosterone, methyltes-tosterone, boldenone, ephedrine, amphetamine, and MDMAwere observed up to 5 μg/L (ephedrine). Salbutamol (a beta-agonist) and furosemide and hydrochlorothiazide (diuretics)were also confirmed in extracts. Very high levels of phospho-diesterase type V inhibitors, sildenafil, tadalafil, vardenafil, andtheir metabolites were found in the fitness center discharges, upto 1.9 μg/L, whereas levels in the municipal wastewater did notexceed 35 ng/L.In the second study, Postigo et al. measured drugs of abuse in
prison sewage waters for the first time.111 This study allowed theunderstanding of drug abuse in a penal complex and evaluated
the suitability of this approach to track and control illicit drugs insuch facilities. Online SPE-LC/MS/MS was used for theirmeasurement. Daily use was observed for methadone (averageof 156 doses/day/1000 inhabitants), alprazolam (129 doses/day/1000 inhabitants), ephedrine (46 doses/day/1000 in-habitants), cannabis (33 doses/day/100 inhabitants), and co-caine (3 doses/day/1000 inhabitants). Sporadic consumptionwas observed for heroin, amphetamine, methamphetamine, andMDMA (ecstasy). This study provided near real-time informa-tion on collective drug use in an anonymous way.Another interesting study by Ginebreda et al. involved the
combination of chemistry and toxicology for assessing the risk ofpharmaceuticals in rivers.112 Twenty-nine pharmaceuticals be-longing to different therapeutic classes were measured in 7sampling points of the Llobregat River basin in Northeast Spain,and the macroinvertebrate community status of the same pointswas assessed. Fish, Daphnia magna, and algae were collected insediment and water samples, and hazard indexes were obtained,on the basis of ecological status (expressed in terms of diversity)and chemical contamination. Each bioassay showed its ownsensitivity with respect to certain pharmaceuticals, with algaebeing the most sensitive. Some compounds, such as ibuprofen,diclofenac, clofibric acid, and gemfibrozil showed effects in all3 bioassays; others, such as erythromycin, only for Daphniamagna or sulfamethoxazole for algae. In general, hazard quotientsincreased when going downstream, and results showed a clearinverse correlation between macroinvertebrate diversity indexesand hazard quotients, which can be tentatively interpreted ascause�effect.The diurnal variability of pharmaceuticals, personal care
products, estrogens, and alkylphenols in wastewater treatmentwas investigated by Nelson et al.113 Hourly samples of tertiarywastewater effluent were analyzed to better understand the rateat which these compounds enter the environment. Severaldistinct patterns of daily cycling were observed. Trimethoprim,sulfamethoxazole, naproxen, estrone, and triclosan varied greatlyduring daily cycles, with less extreme cycles for other com-pounds, such as azithromycin, atenolol, iopromide, and gemfi-brozil. Peak concentrations for most compounds occurred inearly evening (5�8 pm), but some compounds, such as carba-mazepine, primidone, fluoxetine, and triclocarban, showed littleor no variability. This study highlights the importance of under-standing the specific cycles of pharmaceuticals, which could aid indeveloping effective sampling strategies to more accuratelycapture their fate and occurrence in wastewater treatment.Hospital wastewater has become of increasing interest. Lin
et al. measured narcotics and drugs that can be drugs of abuse in 5hospital effluents in Taipei, Taiwan, along with two wastewatertreatment plants and two rivers.114 Of the target drugs, mor-phine, codeine, methamphetamines, and ketamine were found insignificant quantities in hospital effluents, up to 1240, 378, 260,and 206 ng/L, respectively. Six other compounds, includingmetabolites, were found at trace levels but below methodquantification limits. Methamphetamine, codeine, and ketaminewere also found at relatively high levels in river waters, up to 405,57, and 341 ng/L, respectively. This study demonstrated thathospital wastewaters can be a significant source of controlledsubstances for environmental waters. Hospital wastewaters werealso sampled in China for antibiotics, along with sewage samplesfrom a nursery, slaughter house, and wastewater treatmentplant.115 LC/MS/MS was used for measurement. Ofloxacinwas found at the highest levels in hospital wastewater, up to
4.24 μg/L Antibiotics were found in highest concentrations atwastewater treatment plants, followed by hospital effluent, theslaughter house, and the nursery. Removal at wastewater treat-ment plants ranged from 18 to 100%.Two new studies investigated the occurrence of illicit drugs in
urban air environments. Cecinato et al. measured illicit psycho-tropic drugs in airborne particulates from 28 cities in Italy.116
Cocaine was found almost everywhere, even though some siteswere rural or suburban. The maximum was recorded in Milan inwinter (0.39 ng/m3), and high values in the northern cities and inRome were approximately 0.16 ng/m3. Besides cocaine, othercannabinoids were also monitored, including Δ9-tetrahydrocan-nabinol, cannabidol, and cannabinol, which were also foundoccasionally but at lower levels than cocaine. Levels were 6�lower in June than in the winter, which is believed to be due to thelower boundary layer in winter and also due to increasedoxidation capacity during the summer. Viana et al. measuredcocaine, heroin, cannabinoids, amphetamines, and other drugs ofabuse in airborne particulates in urban environments in Spain.117
Daily mean concentrations of cocaine were 204�480 pg/m3,which were up to 1 order of magnitude higher than in Italy andPortugal; cannabinoids were present at 27�44 pg/m3, amphet-amine at 1.4�2.3 pg/m3, and heroin at 9�143 pg/m3. Resultsshowed common consumption trends for cocaine and cannabis(weekend maxima) but markedly different consumer groups. Airlevels were not sufficient to cause harm for individuals’ publichealth.Harman et al. investigated trends in illicit drug use over 1 year
using polar organic chemical integrative samplers (POCIS)deployed in wastewater treatment plants in Norway.118 Elevenout of 13 target drugs were detected. Amphetamine andmethamphetamine showed similar peaks in concentration duringthe course of a year, as did cocaine and two of its metabolites.Low levels of ecstasy were also observed, with a prominent peakin May and steady increase to the end of the year. An anti-histamine also showed a clear increase in use during the summermonths, as expected. Estimations of cocaine use averagedbetween 0.31 and 2.8 g/day per 1000 inhabitants.One concern related to pharmaceuticals is the use of sludge/
biosolids from wastewater treatment for land application andpotential entry into groundwater or crops. Two new studiesaddressed this concern. Karnjanapiboonwong et al. measuredpharmaceuticals and personal care products in soil and ground-water at a land application site that receives treated wastewatertreatment effluent in West Texas.119 This site has been receivingtreated wastewater for 70 years to remove nutrients and irrigatenonedible crops. Ibuprofen, EE2, ciprofloxacin, triclosan, andother compounds were measured quarterly for 9 months. Con-taminants were found up to 319 ng/g and 1745 μg/L in soil andgroundwater, respectively. Data indicated that PPCPs can trans-port both vertically and horizontally in the soil and eventuallyreach groundwater following land application. Another study byWu et al. analyzed 14 PPCPs in biosolids and soils receivingbiosolids application in the U.S.120 Pressurized liquid extraction,SPE, and LC/MS/MS were used for measurement. Except forcarbamazepine-10,11-epoxide, all target compounds were de-tected in the biosolids. Diphenhydramine, fluoxetine, triclosan,and triclocarban were detected up to 23 μg/g (triclocarban).Several of the PPCPs were also detected in agricultural soilsamended with these biosolids, and some (carbamazepine, di-phenhydramine, and triclocarban) were persistent. Levels oftriclocarban were found up to 0.2 μg/g, with the others at low
ng/g. Levels in the soil were generally 2�3 orders of magnitudelower than in biosolids, likely due to dilution, degradation, andleaching.Wetlands were the focus of a new study by Vazquez-Roig et al.
in Valencia, Spain.121 In this study, 17 pharmaceuticals weremeasured. Fifteen of the 17 were detected, at concentrations upto 17 μg/L; several pharmaceuticals were also detected in thesediments. Surface water, wastewater, and sediments were thefocus of another study by Langford and Thomas, who measuredpharmaceutical metabolites in the Norwegian aquatic environ-ment.122 Metabolites of carbamazepine (carbamazepine-10,11-epoxide), metoprolol (alpha-hydroxy metoprolol), and simvastatin(hydroxy simvastatin) were detected in surface waters fromOslofjord at concentrations up to 108 ng/L. Alpha-hydroxymetoprolol and simvastatin hydroxy carboxylic acid were alsodetected in sediments at low ng/L levels. These data show that, inaddition to the parent drugs, pharmaceutical metabolites are alsobeing discharged into marine surface waters and sediments ofNorway.Several other studies investigated the presence of pharmaceu-
ticals in biota. For example, Schultz et al. measured the uptake ofantidepressants in fish from twoU.S. effluent-impacted streams.123
Brain tissue from native white sucker fish was sampled fromBoulder Creek, CO, and Fourmile Creek, Iowa. Antidepressantswere not present in waters upstream from the effluent outfalls butwere present at points downstream at ng/L levels, even as far as8.4 km downstream. Fluoxetine, sertraline, and their degradateswere the primary antidepressants observed in fish brain tissue, atlow ng/g levels. This study demonstrated that the composition ofantidepressants in brain tissue from exposed fish differs substan-tially from that observed in streamwater and sediment, suggestingselective uptake. Lahti et al. measured uptake of low levels of fivepharmaceuticals (diclofenac, naproxen, ibuprofen, bisoprolol, andcarbamazepine) in rainbow trout exposed in an experimentalstream.124 Blood plasma and bile were monitored for uptakeand bioaccumulation. The average bioaccumulation factor inplasma ranged from below 0.1 to 4.9; bioaccumulation in fish bilewas 2�4 orders of magnitude higher. In another study from Sweden,Fick et al. investigated pharmaceutical plasma levels of fish exposedto treated sewage effluents.125 Of interest was whether bloodplasma levels could reach human therapeutic levels. LC/MS/MSand GC/high resolution-MS were used for measurement. Theprogestin, levonorgestrel, was quantified in fish blood plasma at8.5�12 ng/mL, which exceeded the human therapeutic plasmalevel and is higher than levels shown to reduce fertility in fish.Uptake in plants was the focus of a study by Jones-Lepp et al.,
who conducted greenhouse experiments on food crops exposedto 3 antibiotics through their water and also a field study of foodcrops irrigated with wastewater effluent known to containemerging contaminants.126 Plants included lettuce, spinach,and carrots (greenhouse study) and peppers, tomatoes, melons,lettuce, watermelon, spinach, and carrots (field study). Green-house results revealed the potential for uptake of one or more ofthe antibiotics evaluated but at very low levels. For crops irrigatedwith treated wastewater, only an industrial flavoring agent,N,N0-dimethylphenethylamine, was consistently found.Fate of Pharmaceuticals: Wastewater Treatment, Drink-
ing Water Treatment, and Photolysis. The investigation oftransformation products (TPs) continues to be a hot area ofresearch for pharmaceuticals. In these studies, LC/MS/MSfragmentation and sometimes accurate mass data are used totentatively identify the TPs. Ternes’ group has also been taking
this a step further by collecting repeated LC fractions with apreparative LC system until there is enough material to obtainadditional NMR spectra to confirm tentative structures. Thestate-of-the-art in this area also typically includes completeproposed transformation pathways. For example, Kormos et al.identified 46 TPs from four X-ray contrast media (iopromide,iomeprol, iopamidol, and iohexol) in aerobic soil�water andriver sediment�water batch systems and used LC/Qq-linear iontrap-MS, along with 1H and 13C NMR, to identify the TPs.127
Detailed reaction pathways were proposed. Fifteen of the TPswere subsequently detected in drinking water, up to 120 ng/L.Biotransformation products of two antiviral drugs, acyclovir andpenciclovir, were identified in another study by Prasse et al. usingLC/linear ion trap-Orbitrap-MS and 1H and 13CNMRNMR.128
For acyclovir, only one TP was found, but 8 TPs were identifiedfor penciclovir, which involved the oxidation of terminal hydro-xyl groups and beta-oxidation followed by acetate cleavage. Oneof these TPs, carboxy-acyclovir, was subsequently found insurface water and drinking water, with concentrations up to3200 ng/L and 40 ng/L, respectively.Kosjek et al. used complementary MS techniques to identify
phototransformation products of ketoprofen, a nonsteroidalanti-inflammatory drug.129 This drug rapidly transformed duringUV irradiation into benzophenone derivatives. GC/MS, GC/MS/MS, and LC/Q-TOF-MS were used to obtain accurate massand fragment information to propose structures for 22 TPs. Withthis information, an overall reaction pathway was constructed.Patterson et al. investigated the fate of 9 recycled water organics,including several pharmaceuticals, EE2, carbamazepine, oxaze-pam, iohexol, and iodipamide.130 For this study, a large-scalelaboratory column experiment was carried out to simulate naturalattenuation during aquifer passage associated with managedaquifer recharge. Carbamazepine and oxazepam did not degradeunder either aerobic or anaerobic conditions, and these resultswere validated in field studies.Sorption onto wastewater sludge solids was investigated by
Stevens-Garmon for 34 contaminants, including amitriptyline,clozapine, verapamil, risperidone, and hydroxyxine, whichshowed high sorption potentials, compared to negatively chargedcompounds.131 Solid-water partitioning coefficients (Kd) werequantified, and 19 of the chemicals studied did not havepreviously reported values. Kim et al. conducted a simulatedrainfall study to evaluate surface runoff as a possible transportmechanism for veterinary antibiotics.132 Of the seven antibioticsstudied, monensin showed the highest concentration in runoffwater (0.22 mg/plot), while erythromycin showed the highestconcentration in runoff sediment samples (0.08 mg/plot). All ofthe antibiotics penetrated the subsurface, but no residuals werefound for sulfamethazine, suggesting that it penetrated deeperinto the soil. These results indicated that aqueous or sedimenterosion control might reduce the transport of veterinary anti-biotics in the environment.Fate in drinking water treatment was the focus of several
studies. For example, Huerta-Fontela used SPEwithUPLC/MS/MS to measure their removal of pharmaceuticals and hormonesin drinking water treatment.133 Thirty-five of the 55 drugs weredetected in the raw source waters, up to 1200 ng/L, and all but 5of these compounds were removed in treatment with prechlori-nation, coagulation, sand filtration, ozonation, granular activatedcarbon filtration, and postchlorination. Phenytoin, atenolol, andhydrochlorothiazide were the most frequently detected pharma-ceuticals in finished drinking water, at ∼10 ng/L. Sotalol and
carbamazepine epoxide were found in <50% of the drinkingwater samples. TPs were not proposed in this study. In anotherstudy, Kleywegt et al. used LC/MS/MS to measure pharmaceu-ticals, hormones, and bisphenol A in 17 drinking water systemsfrom Ontario, Canada.134 Twenty-seven of the 48 target con-taminants were found in source water, finished drinking water, orboth. Drinking water systems using river and lake source watershad the most (>90%) detections, with carbamazepine, gemfi-brozil, ibuprofen, and bisphenol A the most frequently detectedin finished drinking water. Removal efficiencies from the use ofgranular activated carbon and UV irradiation were also evaluated.The first data on the occurrence of pharmaceuticals and steroidsin French drinking water was reported by Vulliet et al.135
Twenty-seven of the 51 target compounds were found in sourcewaters, and 25 compounds were found in drinking water,including salicylic acid, carbamazepine, and atenolol. The effec-tiveness of the different treatments was also discussed.Products resulting from the reaction of gemfibrozil with chlo-
rine were reported by Krkosek et al., who used GC/MS, LC/ESI-MS/MS, and 1H NMR to identify the disinfection byproducts.136
Reactions were consistent with electrophilic aromatic substitutionand one, two, or three chlorine atoms incorporated into thearomatic ring. The following DBPs were identified: 5-(4-chloro-2,5-dimethylphenoxy)-2,2-dimethylpentanoic acid), 5-(4,6-di-chloro-2,5-dimethylphenoxy)-2,2-dimethylpentanoic acid, and5-(3,4,6-trichloro-2,5-dimethylphenoxy)-2,2-dimethylpentanoicacid. Chlorine dioxide reactions with fluoroquinolone antibioticswas investigated by Wang et al.137 Reaction kinetics were highlypH dependent, with a reactivity trend of ofloxacin > enrofloxacin> ciprofloxacin∼ norfloxacin∼ lomefloxacin. pipemidic acid.The piperazine ring was the primary reactive group towardchlorine dioxide. Reaction pathways were proposed, but anti-bacterial activity is likely not eliminated because there was littledestruction of the quinolone ring.Chemical and toxicity evaluation of the reaction of ozone with
the antibiotic sulfamethoxazole was investigated by Gomez-Ramos et al.138 Two main transformation pathways were pro-posed, which involved the preferential attack of molecular ozoneor OH radicals, leading to the formation of 6 intermediates thatwere identified using LC/Q-TOF-MS. Reactions involved hy-droxylation of the benzene ring, oxidation of the amino group onthe benzene ring, oxidation of the methyl group and the doublebond in the isoxazole ring, and S�N bond cleavage. Reaction ofantibiotics with potassium permanganate was the focus ofanother study by Hu et al.139 LC/MS/MS was used to identifyseveral DBPs, including 12 from ciprofloxacin, which wereconsistent with oxidation of the tertiary aromatic and secondaryaliphatic amine groups on the piperazine ring and the cyclopro-pyl group. Seven DBPs were identified for both lincomycin andtrimethoprim. Detailed oxidation pathways were proposed.Subsequent bacterial growth inhibition assays showed that theproducts had lost most of their antibacterial potency, suggestingthat permanganate could be effective for eliminating theirpharmaceutical activity in drinking water.Dioxin photolysis products had been reported for triclosan
recently, and Buth et al. followed up this work by investigat-ing sediment cores for their presence in real environmentalsamples.140 In this study, two sediment cores from a waste-water-impacted depositional zone of the Mississippi River wereanalyzed for triclosan using UPLC/MS/MS and for a suite ofpolychlorinated dioxins and furans using GC/high resolution-MS. 2,8-Dichlorodibenzo-p-dioxin was detected at levels that
correlated with the use of triclosan since the 1960s. Three otherdioxin congeners, 2,3,7-trichlorodibenzodioxin, 1,2,8-trichloro-dibenzodioxin, and 1,2,3,8-tetrachlorodibenzodioxin, which areknown photoproducts of chlorinated derivatives of triclosan,were also detected with similar trend profiles. The profiles didnot correlate with higher chlorinated dioxin homologues or anychlorinated furan homologues but were consistent with thephotolysis of triclosan and its chlorinated derivatives that formduring wastewater chlorine disinfection. These dioxin derivativeshave increased over time, such that they now constitute up to31% of the total dioxin pool.The photolysis of diclofenac was investigated by Schulze et al.141
Effect-directed analysis revealed that the photolysis product,2-[2-(chlorophenyl)amino]benzaldehyde, was responsible for theenhanced toxicity to green algae observed following the reaction.LC was used to fractionate products in the reaction mixture,and GC/MS was used to identify this TP. Its EC50 was a factor of10� lower than for diclofenac. Photolysis products of the drugTamiflu (oseltamivir) and oseltamivir carboxylate were investi-gated by Goncalves et al., who used UPLC/Q-TOF-MS topropose their structures.142 Reactions involved hydration of thecyclohexane ring, ester hydrolysis, intramolecular cyclization, andcleavage of the ethylpropoxy side chain. Finally, Yuan et al. studiedthe photodegradation and toxicity changes of 3 antibioticswithUVand UV/H2O2 treatment.143 GC/MS was used to identify thephotoproducts. Toxicity, as assessed usingVibrio fischeri, increasedfollowing UV photolysis, with the photoproducts preserving thecharacteristic structure of the parents. On the other hand, UV/H2O2 treatment resulted in more extensive reactions and subse-quent detoxification.Hormones. Wise et al. reviewed sources of estrogens in
surface water, source waters, and drinking water and posed thequestion: “Are oral contraceptives a significant contributor to theestrogenicity of water?”144 The removal of estrogens throughwater disinfection process and formation of byproducts was thefocus of another review by Pereira et al.145 Oxidative treatmentsare effective for removing estrogens, but DBPs are generated.Structures of 46 natural estrogen and synthetic estrogen (EE2)DBPs are presented, along with the oxidation/disinfectionprocesses that give rise to them. Liu et al. created a new methodfor 28 steroids, including 4 estrogens, 14 androgens, 5 progesto-gens, and 5 glucocorticoids in surface water, wastewater, andsludge.146 LC/MS/MS was used, combined with SPE, ultrasonicextraction, and silica gel cleanup. Method detection limits rangedfrom 0.01 to 1.4 ng/L and 0.08�2.1 ng/g for environmentalwaters and sludge, respectively. Langdon et al. published anextensive, Australia-wide survey of personal care products andendocrine disruptors in biosolids, including estrone (E1), E2, E3,and EE2.147 Levels were higher in samples from anaerobictreatment than aerobic treatment. E1 was the only hormonedetected, in 4 of the 14 samples, up to 0.28 mg/kg in thebiosolids. GC/MS with isotope dilution was used for analysis.
’DRINKING WATER AND SWIMMING POOL DISIN-FECTION BYPRODUCTS
Drinking Water DBPs. Drinking water DBPs are formed bythe reaction of disinfectants (chlorine, chloramines, ozone,chlorine dioxide, etc.) with natural organic matter (NOM) andbromide or iodide in source waters. They can also form by thereaction of disinfectants with other organic contaminants, andthere is an increasing amount of research in this area. One
particularly important discovery in this regard was the formationof high levels of N-nitrosodimethylamine (NDMA) in drinkingwater that resulted from the reaction of ozone with a fungicide(tolylfluanide) used in Europe.2 New areas in drinking waterDBP research include the study of highly genotoxic or carcino-genic DBPs that have been recently identified, issues withincreased formation of many of these with the use of alternativedisinfectants (e.g., chloramines and ozone), and routes ofexposure besides ingestion. In this regard, there have been severalrecent studies of DBPs in swimming pools. Other trends includethe development of UPLC/MS/MS methods and the combina-tion of analytical chemistry with toxicology to account fortoxicological effects with DBPs measured. In addition, nearreal-time methods are being developed, which could give drink-ing water utilities a better understanding and control over DBPlevels received by consumers and improve exposure character-izations for epidemiologic studies.Toxicologically important DBPs include brominated, iodin-
ated, and nitrogen-containing DBPs (“N-DBPs”). BrominatedDBPs are generally more carcinogenic than their chlorinatedanalogues, and new research is indicating that iodinated com-pounds are more toxic than their brominated analogues.1 Bro-minated and iodinated DBPs form due to the reaction of thedisinfectant (such as chlorine) with natural bromide or iodidepresent in source waters. Coastal cities, where groundwaters andsurface waters can be impacted by salt water intrusion, and someinland locations, whose surface waters can be impacted by naturalsalt deposits from ancient seas or oil-field brines, are examples oflocations that can have high bromide and iodide levels. Asignificant proportion of the U.S. population and several othercountries now live in coastal regions that are impacted bybromide and iodide; therefore, exposures to brominated andiodinatedDBPs are of growing interest. This year, another sourceof iodine has been discovered, X-ray contrast media, whichcontributes to the formation of iodo-DBPs. This new discoveryis detailed in the section on DBPs of Pollutants.Early evidence in epidemiologic studies indicates that bromi-
nated DBPs may be associated with reproductive and develop-mental effects, as well as cancer. Brominated and iodinated DBPsof interest include iodo-acids, bromonitromethanes, iodo-trihalo-methanes (iodo-THMs), brominated forms of MX (3-chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone), haloaldehydes,and haloamides. Iodinated DBPs are increased in formation withchloramination, and bromonitromethanes are increased with theuse of preozonation. Besides haloamides, otherN-DBPs of interestinclude NDMA and other nitrosamines, which can form witheither chloramination or chlorination (if nitrogen-containingcoagulants are used in treatment). Five nitrosamines (NDMA,N-nitrosodiethylamine, N-nitrosodipropylamine, N-nitrosodiphe-nylamine, and N-nitrosopyrrolidine), as well as formaldehyde(which is a DBP from treatment with ozone, chlorine dioxide,or chlorine), are currently listed on the U.S. EPA’s new Con-taminant Candidate List (CCL-3) (http://water.epa.gov/scitech/drinkingwater/dws/ccl/ccl3.cfm). Chloramination has become apopular alternative to chlorination for plants that have difficultymeeting the regulations with chlorine, and its use has increasedwith the new Stage 2Disinfectants (D)/DBPRule (www.epa.gov/safewater/disinfection/stage2).Potential health risks from DBPs include cancer and repro-
ductive/developmental effects, with bladder cancer showing themost consistency in human epidemiologic studies from severalcountries. While this Review does not typically cover toxicology
or epidemiology studies, an important epidemiologic study wasjust published that bears mentioning here. Cantor et al. con-ducted a new case-control bladder cancer study and found anenhanced risk for bladder cancer (odds ratio 5.9) for people witha particular genotype, which can be found in approximately 25%of the U.S. population.2 Their study also found that dermal/inhalation exposure from showering, bathing, and swimming wasa significant risk factor. The findings strengthen the hypothesisthat DBPs cause bladder cancer and suggest possible mecha-nisms, as well as classes likely to be implicated.Several reviews have been published the last 2 years on DBPs.
Charrois published a nice review on the analysis of emergingDBPs in drinking water, which included detailed discussions ondifferent analytical techniques that can be used to measurethem.148 In addition, Charrois presented a nice historical per-spective on the beginnings of this research area, with mention ofthe Water Chlorination Conferences begun by Robert Jolley(also published in a series of books), on up to the establishmentof a Gordon Research Conference on Drinking Water DBPs in2006. Swimming pool DBPs were also discussed.Richardson published a new review on DBP formation and
occurrence in drinking water.149 This review provides a compre-hensive listing of >600 DBPs identified from different disinfectantsand disinfectant combinations (updating a 1998 encyclopediaarticle containing these original comprehensive lists) and includesdiscussion of formation and occurrence, issues with alternativedisinfectants, route of exposure, and formation of “pollutant”DBPs.Combining Chemistry with Toxicology. More studies are
combining DBP identification/measurement efforts with toxi-cology to understand their potential health effects. For example,Pressman et al. reported the second phase of a large integratedmultidisciplinary study (called the Four Lab Study) involving thecollaboration of chemists, toxicologists, engineers, and riskassessors from the 4 National Research Laboratories of theU.S. EPA, as well as collaborators from academia and the waterindustry.150 This paper described a new procedure for producingchlorinated drinking water concentrates for animal toxicologyexperiments, the comprehensive identification of >100 DBPs,and quantification of 75 priority and regulated DBPs. Complexmixtures of DBPs were produced by concentrating natural sourcewaters with reverse osmosis membranes, followed by addition ofbromide and treatment with chlorine. By concentrating theNOM first and disinfecting with chlorine afterward, DBPs(including volatiles and semivolatiles) were formed and main-tained in a water matrix suitable for animal studies. DBPs wererelatively stable over the course of the animal studies (125 days)with multiple chlorination events (every 5�14 days), and asignificant proportion of the total organic halogen was accountedfor through a comprehensive identification approach. ManyDBPs were reported for the first time, including previouslyundetected and unreported haloacids and haloamides. Thenew concentration procedure not only produced a concentrateddrinking water suitable for animal experiments but also provideda greater TOC concentration factor (136�), enhancing thedetection of trace DBPs that are often below detection usingconventional approaches.Discovery of New DBPs. Increasingly, ESI-MS/MS is being
used to discover new, highly polar DBPs. For example, Zhao et al.identified three new haloquinone DBPs in drinking water usingLC/ESI-MS/MS: 2,6-dichloro-3-methyl-1,4-benzoquinone, 2,3,6-trichloro-1,4-benzoquinone, and 2,6-dibromo-1,4-benzoquinone.151
Following their discovery in chlorinated drinking water, they were
quantified, along with 2,6-dichloro-1,4-benzoquinone. Levels ran-ged from 0.5 to 165 ng/L. An unusual feature about thesecompounds is that, using negative ion-ESI, they form (M + H)�
ions through a reduction step, rather than the classic (M � H) �
ions that are typically observed. The authors used tandem-MS andaccurate mass measurements to confirm the identity of theseunusual ions. This effort was followed up by an interesting study toinvestigate interactions of these haloquinones with oligodeoxy-nucleotides to understand potential binding to DNA.152 Asmeasured using ESI-MS, the binding affinity of 2,6-dibromo-1,4-benzoquinone to oligodeoxynucleotides was similar to that ofethidium bromide, a carcinogen that is well-known for intercalat-ing with DNA. Tandem MS confirmed the formation of 1:1 and2:1 complexes of 2,6-dibromo-1,4-benzoquinione with oligodeox-ynucleotides. The chlorobenzoquinones also formed 1:1 adducts,but their binding was much weaker. Binding affinities followed theorder: 2,6-dibromo-1,4-benzoquinone. 2,6-dichloro-1,4-benzo-quinone > 2,6-dichloro-3-methyl-1,4-benzoquinone ∼ 2,3,6-tri-chloro-1,4-benzoquinone. Zhai and Zhang used precursor ionscans with UPLC/MS/MS to identify new polar brominatedDBPs formed in chlorinated water, including 2,4,6-tribromophe-nol, 3,5-dibromo-4-hydroxybenzoic acid, 2,6-dibromo-1,4-hydro-quinone, and 3,3-dibromopropenoic acid.153 In this study, variouspolar brominated DBPs were found to reach maximum levels atdifferent chlorine contact times, suggesting that high molecularweight brominatedDBPsmight undergo decomposition or furtherreactions to form lower molecular weight DBPs and finally tohaloacetic acids and trihalomethanes. Reaction pathways weresuggested for the formation of brominated DBPs from SuwanneeRiver humic acid, bromide, and chlorine.A newly synthesized chloroformate derivatizing agent was
used in another paper to aid in the identification of 13 unknownhighly polar DBPs in ozonated fulvic and humic acid solutionsand ozonated drinking water.154 This derivatizing agent wasspecifically designed to derivatize carboxyl, hydroxyl, and aminegroups, forming multiply substituted nonpolar derivatives thatcan be easily extracted from water and determined by GC/negative chemical ionization (NCI)-MS.N-DBPs. Bond et al. published a review on the occurrence and
control of N-DBPs in drinking water.155 It was stressed that theimpact of water treatment processes on N-DBP formation iscomplex and variable, such that coagulation and filtration canefficiently remove cyanogen halide precursors, but they are lessefficient for removing other N-DBP precursors, such as aminoacids and amines. Oxidation before final disinfection can increasehalonitromethane formation but decrease NDMA forma-tion. Chloramination can increase both NDMA and cyanogenhalides relative to chlorination. Several new studies focused onthe formation and source of N-DBPs. Yang et al. investigated theformation of cyanogen chloride, dichloroacetonitrile, and chloro-picrin during chloramination of several different precursors,including alpha-amino acids, amines, dipeptides, purines, andpyrimidines.156 Reaction pathways were proposed. 15N-labeledmonochloramine revealed that the nitrogen in N-DBPs canoriginate from both NH2Cl and organic-N compounds. Allprecursors formed cyanogen chloride, with highest levels fromglycine; dichloroacetonitrile was formed from the chloramina-tion of glutamic acid, cytosine, cysteine, and tryptophan, andmost precursors generated chloropicrin. Aldehydes and nitrileswere identified as intermediates using negative ion-ESI-MS.Chu et al. investigated precursors of dichloroacetamide, themost
common haloamide formed in chlorinated and chloraminated
drinking water.157 In a reservoir in China, dissolved organic matterwas separated into 6 fractions by a series of resin elutions. Thehydrophilic dissolved organic matter fraction formed the highestlevels of dichloroacetamide. Fluorescence excitation�emissionmatrix spectra revealed protein-like substances in this fraction,made up of amino acids, which were likely the dichloroacetamideprecursors. Subsequent reactions of 20 amino acids with chlorinerevealed that 7 amino acids (aspartic acid, histidine, tyrosine,tryptophan, glutamine, asparagine, and phenylalanine) could formdichloroacetamide during chlorination, with yields of 0.231, 0.189,0.153, 0.104, 0.078, 0.058, and 0.050 mmol/mol amino acid.Nitrosamines. Nitrosamines continue to be of interest, since
they were discovered to be DBPs in 2002. NDMA is a probablehuman carcinogen, and there are toxicological concerns regard-ing other nitrosamines. NDMA was initially discovered inchlorinated drinking waters from Ontario, Canada, and has sincebeen found in other locations. The detection of NDMA indrinking water is largely due to improved analytical techniquesthat have allowed its determination at low ng/L concentrations.NDMA is generally present at low ng/L in chloraminated/chlorinated drinking water, but it can be formed at much higherlevels in wastewater treated with chlorine. It was also recentlyshown to form when waters containing a microbial degradationproduct of the fungicide, tolylfluanide, were ozonated.2 NDMA isnot currently regulated in the United States for drinking water,but the U.S. EPA has recently made a preliminary decision torecommend it for regulation in drinking water, along with a groupof other nitrosamines, for which the U.S. EPA has nationaloccurrence and toxicity data. NDMA is regulated in Ontario,Canada (at 9 ng/L), under Ontario’s Safe Drinking Water Act(http://www.e-laws.gov.on.ca/html/regs/english/elaws_regs_030169_e.htm), and a Canadian national drinking water guide-line for NDMA is also under development (www.hc-sc.gc.ca/ewh-semt/consult/_2010/ndma/index-eng.php). NDMA wasincluded in the U.S. EPA’s second Unregulated ContaminantMonitoring Rule (UCMR-2), along with 5 other nitrosamines(N-nitrosodiethylamine, N-nitrosodibutylamine, N-nitrosopropyl-amine, N-nitrosomethylethylamine, and N-nitrosopyrrolidine),and national occurrence data are currently available (http://water.epa.gov/lawsregs/rulesregs/sdwa/ucmr/data.cfm#ucmr2010). Inaddition, NDMA and 4 other nitrosamines are also on the U.S.EPA’s final CCL-3 (http://water.epa.gov/scitech/drinkingwater/dws/ccl/ccl3.cfm).Nawrocki and Andrzejewski published an excellent review on
nitrosamines, which included methods for their analysis, occur-rence in drinking water and wastewater, precursors of NDMA indrinking water and wastewater, removal of nitrosamine precur-sors in water treatment, mechanisms of formation for NDMA,and methods to remove NDMA.158 The authors conclude with alist of research needs, which includes the need to identify specificN-containing groups present in NOM, systematic research onthe presence of secondary amines in surface water and theirbehavior in drinking water treatment, and the investigation ofNDMA contamination in surface and groundwaters in Europe.A new GC/MS nitrosamine method, capable of measuring 9
nitrosamines, was created using GC/CI-ion trap-MS/MS.159
Because NDPhA decomposes at common GC injection porttemperatures (and is why this nitrosamine is not included in theEPA Method that also uses GC/CI-MS/MS), the authorsmonitor its decomposition product, diphenylamine, to enableits determination. It also uses methanol as the CI reagent gas anddoes not require large volume injectors. Detection limits for
NMEA were 2 ng/L; all of the other nitrosamines could bedetected down to 1 ng/L. The method was subsequently used tomeasure nitrosamines in drinking water and in swimming poolwater, where NPYR was found in all samples at concentrationsgreater than 50 ng/L.Several studies examined the formation and fate of nitrosa-
mines. Patterson et al. examined the fate of trace organiccompounds, including NDMA and NMOR, in recycled waterduring managed aquifer recharge.130 NDMA andNMOR did notdegrade under either aerobic or anaerobic conditions (half-life >50 days), such that natural attenuation during aquifer passagealone may not allow extracted water to meet regulatory limits.Van Huy et al. investigated the formation potential for NDMA ingroundwater and river water in Tokyo.160 Twenty-three ground-waters and 18 river waters were collected, and NDMA wasanalyzed using LC/MS/MS. NDMA precursors ranging from4 to 84 ng-NDMA equivalents/L in groundwater and from 11 to185 ng in river water. Molecular size fractionation of the riverwaters revealed that NDMA precursors were mostly in the<0.5 kDa fraction, followed by 0.5�3 kDa.Templeton and Chen reported the first measurements of
NDMA and seven other nitrosamines in the United Kingdom.161
NDMA was found only in a few samples from one distributionsystem, slightly above the detection limit of 0.9 ng/L. Otherwise,the majority of the samples collected from 6 systems containedno detectable levels. However, N-nitrosobutylamine (NDBA)was consistently detected in one distribution system, up to 6.4ng/L. A fascinating study by Kemper et al. investigated the role ofseveral consumer products (shampoos, laundry detergents, dishwashing liquids, and fabric softeners) in the formation ofnitrosamines.162 This study was conducted in order to addressthe question surrounding relatively high levels of nitrosamines intreated wastewaters that are correlated with wastewaters impacts,rather than total dissolved organic nitrogen. Nitrosamines wereformed from several of these products when they were reactedwith monochloramine or chlorine, and the authors showed clearevidence that quaternary amines (including polymers) used inthese products form nitrosamines. In fact, the quaternary aminepolymers were more reactive than the monomers, and preozona-tion or prechlorination did not significantly reduce nitrosamineformation. EPAMethod 521 (GC/CI-MS/MS) was used for themeasurements. There was also important new information onthe reaction of monochloramine and chlorine with polyDAD-MAC polymers used as coagulants in drinking water treatment.Results showed that the polymers themselves are reacting withchlorine to form NDMA and other nitrosamines. This wasproven by synthesizing polyDADMAC (to control the purityand eliminate contribution of monomers). These findings areimportant because nitrosamine formation is often attributed tolower order amine impurities, but these results clearly show thatquaternary amine polymers can form NDMA.Finally, an interesting paper was published on tobacco-specific
nitrosamines in water.163 While these nitrosamines would origi-nate not as DBPs from drinking water treatment but as watercontaminants from the use of cigarettes and smokeless tobacco.In particular, smokeless tobacco products can contain high levelsof tobacco-specific nitrosamines (up to 90 mg/kg in the U.S. andhigher in other countries). NDMA can be excreted in urine andenter wastewaters. Tobacco-specific nitrosamines include N0-nitrosonornicotine and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone, which are carcinogenic. There are currently no data ontheir occurrence, fate, and removal in wastewater and drinking
water treatment plants, and the authors suggest that they are anunderappreciated contaminant that may pose an environmentalhealth risk.Alternative Disinfection Technologies Using Iodine, UV,
and Other Treatments. Two papers investigated DBP forma-tion from point-of-use treatments. In the first, Smith et al.measured the formation of iodo-DBPs (iodo-THMs and iodo-acids) and nitrosamines from 3 different iodine point-of-usetreatments that are used for the military in remote locations(iodine tincture), campers and hikers (iodine tablets), and thenew Lifestraw, a reusable device marketed toward rural con-sumers in developing countries that uses an iodinated anionexchange resin with activated carbon post-treatment.164 Con-trolled laboratory experiments were carried out using fourdifferent source waters with widely ranging dissolved organiccarbon, specific UV absorbance (SUVA), and bromide levels.GC/EI/MS and derivatization with GC/NCI-MS were used tomeasure the iodo-THMs and iodo-acids, respectively; GC/CI-MS/MS (EPA Method 521) was used to measure the nitrosa-mines. Total organic chlorine (TOCl), total organic bromine(TOBr), and total organic iodine (TOI) were also measuredusing the combustion-IC method described earlier. Iodoformwas the predominant iodo-DBP formed and was substantial, atroughly 20�60% on a molar basis of the chloroform formationobserved during treatment of the same waters with a 6-foldhigher chlorine dose. Iodine tincture produced the highest levelsof iodoform, which ranged from 114 to 268 μg/L. Despite higheriodine residuals, iodoform formation during treatment withiodine tablets was lower, ranging from 74 to 132 μg/L. Whiledichloroiodomethane and chlorodiiodomethane were detected,they were more than an order of magnitude lower concentrationthan iodoform. Iodoacetic acid, bromoiodoacetic acid, diiodo-acetic acid, (E)-3-bromo-3-iodopropenoic acid, and (E)-2-iodo-3-methylbutenedioic acid were also formed with iodine tincturetreatment, with diiodoacetic acid and iodoacetic acid dominant inthis class, but present at <11% of the iodoform levels. Lifestraw,which showed no iodine residual, produced the lowest iodo-DBPs among the 3 iodine treatments, with iodoform detected inonly one of the disinfected waters at 23 μg/L. TOI dominatedwith iodine tincture, while TOCl dominated with chlorine andchloramine treatment, carried out for comparison. On the basisof previous measurements of mammalian cell cytotoxicity of theindividual THMs, a person consuming drinking water treatedwith iodine tincture would receive the same THM-associatedcytotoxic exposure in 4�19 days as a consumer of the samewaters treated with a 6-fold higher dose of chlorine over 1 year.Finally, nitrosamines were measured in samples from the Life-straw because nitrosamines can form from the contact of oxidantswith ion-exchange resins. While nitrosamines were initiallyobserved in the first few flushes of water through the Lifestraw,they rapidly declined to low levels (4 ng/L).UV treatment is gaining popularity in the U.S. because it is
effective against resistant pathogens, including Cryptosporidium,and it has not been found to directly produce DBPs. However,studies are finding that when UV (particularly medium pressure-UV) is used along with postchlorination, it can enhance theformation of some DBPs. Low-pressure UV emits only 254 nm,but medium-pressure UV emits a much broader spectrum (often200�400 nm). Shah et al. investigated the impact of UVdisinfection coupled with chlorination or chloramination onthe formation of halonitromethanes and haloacetonitriles indrinking water.165 Medium pressure-UV with postchlorination
increased chloropicrin formation by an order of magnitude abovethe 0.19 μg/L median level from EPA’s Information CollectionRule database. Formation was 2.5� higher for postchlorination vspostchloramination. Experiments indicated that the nitratingagent, NO2 radical, was generated during nitrite photolysis andwas primarily responsible for halonitromethane promotion. Lowpressure-UV treatments did not enhance its formation. Whenwaters were prechlorinated prior to treatment with mediumpressure-UV, chloropicrin formation doubled, but effects onhaloacetonitrile formation were not significant. In another study,Reckhow observed an increase in formation of trichloronitro-methane (chloropicrin) and 1,1,1-trichloropropanone whenmedium-pressure UV was followed by chlorination.166 In contrast,low-pressure UV did not cause an increase in trichloronitromethaneformation. The authors propose that photonitration leads to theformation of new nitroorganics during UV treatment and theseform halonitromethanes during subsequent chlorination.Other Formation/Fate Studies. The effects of enhanced
coagulation on polar halogenated DBPs during chlorination wasthe focus of another paper by Xiao et al.167 UPLC/ESI-MS/MSwas used with precursor ion scans to identify the polar DBPs.While enhanced coagulation is generally used to remove NOMand lower the formation of DBPs, these results showed thepresence of several polar DBPs in the water treated by enhancedcoagulation that were not formed with coagulation. In addition,enhanced coagulation altered the speciation of several halogenatedDBPs, such that the ratio of bromine-containingDBPs to chlorine-containing DBPs was increased. This phenomenon was observedfor both polar and nonpolar DBPs, but polar DBPs were impactedmore. DBPs formed from algal matter was the focus of a study byWei et al.168 Model algal cellular compounds (bovine serumalbumin, fish oil, and starch) and Microcystis aeruginosa and itsextra-cellular organic matter were chlorinated in the presence orabsence of bromide. All brominated THMs were generated, alongwith bromochloro- and dibromoacetic acid, and there was a goodcorrelation between the model compound data and data fromspecific algal species. DBPs formed from wastewater organics wasthe focus of another study by Liu and Li, who used real wastewaterinfluent, effluent, and model compounds (humic acid, tannic acid,glucose, starch, glycine, and bovine serum albumin) to representdifferent types of organic pollutants in wastewater discharges.169
While biodegradation occurring during wastewater treatmentremoved some DBP precursors, it also formed some new pre-cursors, in the formof solublemicrobial products, whichmay be animportant source of DBP precursors in natural waters.DBPs of Pollutants. Studies of DBPs are going beyond the
“classic” DBPs formed by the reaction of NOM with disinfec-tants, such that reactions of environmental pollutants withdisinfectants are increasingly being studied. Contaminant DBPshave been recently reported from pesticides, pharmaceuticals,personal care products, microcystins, and terpenoids. Some ofthis research has been conducted in order to find ways to degradeand remove these contaminants from wastewater effluents anddrinking water sources, but some of this research is beingconducted to determine the fate of these contaminants indrinking water treatment. It is not surprising that DBPs canform from these contaminants, as many of them have activatedaromatic rings or other structural groups that can readily reactwith oxidants like chlorine and ozone. However, until recently,these types of DBPs were not investigated.Duirk et al. discovered the formation of highly toxic iodo-
DBPs (iodo-acids and iodo-THMs) when iodinated X-ray
contrast media are treated with chlorine or chloramines.170 Thisdiscovery came about from a curiosity in a previous occurrencestudy, which showed the presence of ppb levels of iodo-DBPs infinished water but nondetect or barely detectable iodide in thesource waters. As a result, other sources of iodine were con-sidered, and X-ray contrast media were subsequently found athigh levels in these drinking water reservoirs, up to 2700 ng/L.LC/MS/MS was used to measure them for the first time indrinking water source waters. Of the X-ray contrast media,iopamidol was found the most often and at the highest levels.In subsequent controlled laboratory experiments, it was alsothe most reactive with chlorine and chloramines, forming thehighest levels of iodo-DBPs. NOM also appears to play arole in their formation, with much higher iodo-DBP levels whenNOM was present in the treated waters. In addition, toxicityexperiments revealed that the reaction mixtures containingiopamidol were much more genotoxic than those without,supporting the formation of these highly genotoxic andcytotoxic DBPs.Krkosek et al. identifiedDBPs from the chlorination of the lipid-
regulator drug, gemfibrozil.171 GC/MS and LC/ESI-MS/MSwithaccurate mass were used to propose structures, and 1H NMR wasused to provide confirmation for isolates. Reactions involved theincorporation of one, two, or three chlorine atoms into thearomatic ring of gemfibrozil, and 3 products were identified:5-(4-chloro-2,5-dimethylphenoxy)-2,2-dimethylpentanoic acid,5-(4,6-dichloro-2,5-dimethylphenoxy)-2,2-dimethylpentanoic acid,and 5-(3,4,6-trichloro-2,5-dimethylphenoxy)-2,2-dimethylpenta-noic acid. Xu reported 6 new chlorination products for theherbicide, chlorotoluron.172 Purge-and-trap-GC/MS was used withUPLC/ESI-MS/MS to identify chloroform, dichloroacetonitrile,1,1-dichloropropanone, 1,1,1-trichloropropanone, dichloronitro-methane, and trichloronitromethane. Reaction pathways were alsoproposed. Chlorination products of phenothiazine and relatedheterotricyclic aromatic hydrocarbons were the focus of anotherstudy by Sekizawa and Onodera, who used GC/MS for theiridentification.173 Oxidation reactions began with the formationof dioxides, followed by chloro-substitution. Two DBPs, 10H-phenothiazine and 10H-phenoxazine, were shown to be weakmutagens in the Ames assay.Wang et al. investigated the DBP formation of the pesticide
aldicarb upon reaction with chlorine, monochloramine, chlorinedioxide, hydrogen peroxide, permanganate, and UV irradiation.174
Aldicarb sulfoxide was formed by reaction with chlorine, mono-chloramine, ozone, and hydrogen peroxide; aldicarb sulfone wasformed by permanganate, and N-chloro-aldicarb was formed bychlorine. Reactions of the pesticide methiocarb with chlorinedioxide were examined by Tian et al.175 Methiocarb sulfoxideand methiocarb sulfone were the major byproducts and formedsimultaneously in the reactions. Reactionmixtures demonstrated ahigher toxicity than the parent pesticide.Also, several other examples were highlighted earlier in the
Pharmaceuticals and Hormones Section. These included chlo-rine byproducts of gemfibrozil, chlorine dioxide byproducts fromfluoroquinolone antibiotics, and ozone and permanganate by-products of antibiotics.New Swimming Pool Research. Swimming pools are being
recognized as an important source of exposure to DBPs. Healthconcerns include increased risk of bladder cancer from exposureto indoor pools and increased risk of asthma for indoor andoutdoor pools.1 Swimming pools continue to be an intense areaof study. LaKind et al. discussed competing issues of health
benefits of swimming vs potential health risks from DBPs andpathogens.176 Pool disinfectants were summarized, along withknown pool DBPs, and recommendations were proposed forimproving the swimming pool environment. Swimming poolwaters were recently shown to be more genotoxic and cyto-toxic than their corresponding tap waters in a new study,which compared chlorination to UV�chlorination and bromo-chlorodimethylhydantoin treatment for indoor and outdoorpools.177,178 The brominated disinfectant, bromochlorodi-methylhydantoin, produced the highest genotoxicity, suggestingthat brominated disinfectants should be avoided. The combina-tion of UV with chlorine reduced the overall toxicity of thetreated waters, and sunlight exposure lowered the cytotoxicity,suggesting photolysis of DBPs to less toxic compounds. Humanalveolar lung cells were used in another study by Schmalz et al. toevaluate potential lung cell damage due to trichloramine andindoor pool air.179 Cell viability decreased with increasingtrichloramine concentration, and inflammatory responses oc-curred at concentrations >10 mg/m3. Indoor pool exposurescaused similar inflammatory effects to lung cells but with muchlower levels, suggesting that trichloramine is not the only agentinducing lung cell damage, but a combination of trichloraminewith other DBPs is likely responsible.Cardador andGallego developed a newheadspace-derivatization-
GC/MS method to measure 9 HAAs in urine. Dimethylsulfateand tetrabutylammonium hydrogen sulfate were used as deriva-tizing agents, yielding detection limits of 0.01 to 0.1 μg/L.180 Thismethod was subsequently demonstrated in a study of swimmersand nonswimmers. No HAAs were detected in the urine ofnonswimmers or swimmers before entering the pool. As a result,HAAs observed in volunteers after swimming could be directlyrelated to swimming pool exposures. Cardador and Gallego usedthis method for a fascinating study of swimmer and workerexposures to HAAs in swimming pools.181 HAAs appear in urineafter 20�30 min of exposure and were eliminated within 3 h. Inthe indoor pool, worker’s urine contained 300 and 120 ng/L ofdichloroacetic acid and trichloracetic acid, respectively, due toexposure to HAA-containing aerosols. Levels were much lower(∼50 ng/L dichloroacetic acid), however, from exposure to theoutdoor pool. After 1 h of swimming in the indoor pool, chloro-,dichloro-, and trichloroacetic acid were present in the swimmers’urine at approximately 560, 2300, and 4400 ng/L, respectively.Exposure estimates indicated that accidental ingestion is themajor route of exposure to HAAs (∼94%), followed by inhala-tion (∼5%) and dermal exposure (∼1%).Richardson et al. carried out a comprehensive DBP character-
ization and mutagenicity assessment for two public swimmingpools, one chlorinated and one brominated, that were part of ahuman exposure study focused on respiratory and genotoxicitybiomarkers.182 More than 100 DBPs were measured, includingmany nitrogenous DBPs likely formed from human inputs(urine, sweat, skin cells). In addition, several new DBPs wereidentified that have not previously been reported for eitherswimming pool water or drinking water. Bromoform levels werehigher in the brominated pool, but brominated DBPs were alsoidentified in the chlorinated pool, due to source waters (fromBarcelona) that were already high in bromide. Surprisingly, thesepool waters had mutagenicity similar to chlorinated drinkingwater, but the toxicity was higher.Schmalz investigated reactions and processes involved in the
formation of trichloramine in swimming pools and the resultingexposure of bathers.183 Formation of trichloramine was favored
over dichloramine andmonochloramine even below substoichio-metric molar ratios of Cl to N. The reaction of chlorine with ureawas relatively slow under conditions relevant for swimmingpools, and the mass transfer of trichloramine to the gas phasewas also relatively slow, with a mass transfer of 20 h for a roughpool water surface or 5.8 days for a still surface. Because a pooltreatment cycle is shorter (∼6�8 h), processes to removetrichloramine could minimize exposure to bathers. Klupfel testedthe removal of DBPs and their precursors using 3 differentnanofiltration membranes.184 One of the membranes success-fully removed dissolved organic carbon and adsorbable organiccarbon by 70 and 80%, respectively.
’SUNSCREENS/UV FILTERS
UV filters used in sunscreens, cosmetics, and other personalcare products have increased in interest due to their presence inenvironmental waters and potential for endocrine disruption anddevelopmental toxicity. A few UV filters have estrogenic effectssimilar to E2 (a natural estrogen), as well as the potential fordevelopmental toxicity.1 Environmental levels of UV filters are notfar below the doses that cause toxic effects in animals. There aretwo types of UV filters: organic UV filters, which work byabsorbing UV light, and inorganic UV filters (TiO2, ZnO), whichwork by reflecting and scattering UV light. Organic UV filters areincreasingly used in personal care products, such as sunscreens,cosmetics, beauty creams, skin lotions, lipsticks, hair sprays, hairdyes, and shampoos. Examples include benzophenone-3 (BP-3),octyl-dimethyl-p-aminobenzoic acid (ODPABA), 4-methylbenzyl-idene camphor (4-MBC), ethylhexyl methoxycinnamate (EHMC),octocrylene (OC), iso-amylmethoxycinnamate (IAMC), and phe-nylbenzimidazole sulfonic acid (PBSA). The majority of these arelipophilic compounds (low water solubility) with conjugated aro-matic systems that absorb UV light in the wavelength range of280�315 nm(UVB) and/or 315�400 nm (UVA).Most sunscreenproducts contain several UV filters, often in combination withinorganic micropigments. Because of their use in a wide variety ofpersonal care products, these compounds can enter the aquaticenvironment indirectly from bathing or washing clothes, via waste-water treatment plants, and directly from recreational activities, suchas swimming and sunbathing in lakes and rivers.
Human exposure was the focus of a new article by Schlumpfet al., who investigated exposure patterns of UV filters in humanmilk from 54 mothers in Switzerland.185 UV filters were presentin 85% of the samples, at levels close to PCBs. Their presence wasclosely linked with the use of cosmetics containing these UVfilters, which indicated that internal exposure resulted fromrepeated application of cosmetics, rather than from generalenvironmental exposure. 4-MBC and OC were the two mostfrequently detected, using GC/MS.
UV filters also continue to be measured in environmentalsamples. For example, Leal et al. measured UV filters and otherxenobiotic contaminants in gray water and investigated bio-logical treatment systems (aerobic, anaerobic, and combinedanaerobic�aerobic) for their removal.186 Due to limited fresh-water resources, gray water, which is the effluent from domesticwashing activities (e.g., laundry, dishwashing, bathing), is in-creasingly being explored for reuse in applications, such aslandscape irrigation and toilet flushing. In this study, all UVfilters were detected in gray water samples at μg/L levels, withlower levels following biological treatment. Generally, removalwas higher under aerobic conditions; however, most were still
detected in the biologically treated gray water. The UV filtersPBSA and EHMC were among the most persistent compounds.Estimated estrogenic potential of the effluent ranged from 0.07 to0.72 ng/L (17β-estradiol equivalents).
Sediment and sewage sludge were the focus of another studyby Zhang et al., who used LC/MS/MS and GC/MS to measurebenzotriazole and benzophenone UV filters.187 Sludge samplescontained up to 6370 ng/g dry weight and sediments up to 389ng/g dry weight. This study was the first to report several of theseUV filters in sediment and sludge. Gago-Ferrero et al. usedpressurized liquid extraction and UPLC/MS/MS to measure 8UV filters in sewage sludge.188 Two major degradation productsof BP-3 were also reported: 4,40-dihydroxybenzophenone and4-hydroxybenzophenone, which were found to be estrogenic.UV filters were found up to 9.17 μg/g dry weight in the sludgesamples from Spain.
New methods continue to be developed, including ones usingUPLC and LC/MS/MS, pressurized-liquid extraction and auto-mated microextraction-GC/MS, and direct analysis in real-time(DART)-MS. New methods for sludge include one by Negreiraet al., who reported a new pressurized liquid extraction-GC/MSmethod for measuring UV filters in sludge, which allowed73�112% recoveries and 17�61 ng/g quantification limits.189
Moeder developed a fully automated microextraction-GC/MSmethod for measuring UV filters and musks in water samples.190
This method enabled the measurement of small samples (800μL) with 34�96 ng/L detection limits. The microextractionsorbents could be reused at least 70 times.
Wick et al. developed a multiresidue method using LC/ESI-MS/MS and LC/APCI-MS/MS for determining 36 emergingcontaminants, including 5 UV filters, in raw and treated waste-water, activated sludge, and surface water.191 Quantificationlimits ranged from 0.5 to 5 ng/L and 2.5�50 ng/L in surfacewaters and wastewater, respectively. Maximum concentrationsup to 5.1 and 3.9 μg/L were found in raw wastewater for the BP-4and PBSA, respectively. This method also allowed the firstidentification of an antidandruff compound (climbazole) inwastewater, up to 1.4 μg/L.
DART-MS was used in a creative method by Haunschmidtet al. to measure 7 UV filters in environmental waters.192 Stir-barsorptive extraction was used to extract analytes from the water,and DART-MS was used to directly measure the analytes fromthe surface of the polydimethylsiloxane-coated stir bars. Detec-tion limits of <40 ng/L were achieved, and the new method wascross-confirmed using a thermodesorption-GC/MS method,which produced comparable concentrations when tested on lakewater samples.
’BROMINATED FLAME RETARDANTS
Brominated flame retardants have been used for many years ina variety of commercial products including children’s sleepwear,foam cushions in chairs, computers, plastics, and electronics.Brominated flame retardants work by releasing bromine freeradicals when heated, and these free radicals scavenge other freeradicals that are part of the flame propagation process. The use ofthese flame retardants is believed to have successfully reducedfire-related deaths, injuries, and property damage. However,there is concern because of their widespread presence in theenvironment and in human and wildlife samples, as well as theirpresence in locations far from where they were produced or used.Polybrominated diphenyl ethers (PBDEs) have been a popular
ingredient in flame retardants since the polybrominated biphe-nyls were banned about 30 years ago. They are environmentallypersistent and lipophilic and bioaccumulate in animals andhumans. PBDEs are made up of 209 possible congeners contain-ing between 1 and 10 bromine atoms, and of these, 23 congenersare of environmental significance.1 In recent years, PBDE levelshave been increasing significantly. The greatest health concerncomes from recent reports of developmental neurotoxicity inmice, but there are also concerns regarding the potential forhormonal disruption and, in some cases, cancer. In 2004, theEuropean Union banned the use of the penta- and octa-BDEsand later, in 2008, banned deca-BDEs.
In 2004, the major U.S. manufacturer of PBDE-based flameretardants (Great Lakes Chemical) voluntarily stopped produ-cing the penta- and octa-BDEs. Earlier studies had suggested thatdeca-BDEwas too large to bioaccumulate and would not be a riskto humans. However, research now shows that it can accumulatein animal tissues (including people) and that it can debrominatein the environment and metabolically to form the lower bromi-nated species (including the octa- and penta-BDEs). SeveralU.S. states banned the penta- and octa-BDEs in 2006, and inDecember 2009, two U.S. producers of deca-BDE agreed tovoluntarily phase it out in the United States (www.epa.gov/oppt/existingchemicals/pubs/actionplans/deccadbe.html). Inaddition, the U.S. EPA issued a new rule in 2006 to complementthe phase-out of the octa- and penta-BDEs, ensuring that nonew manufacture or importation of these chemicals can occurwithout first being subject to U.S. EPA evaluation (www.epa.gov/EPA-TOX/2006/June/Day-13/t9207.htm).
However, despite the halt in manufacture of most of thesePBDEs in North America and Europe, they are still present inmany consumer products sold previously and can be releasedinto the environment during use and disposal. In addition, thereis still the possibility of importing products that contain them.Four of the PBDEs (2,20,4,40-tetra-BDE (BDE-47), 2,20,4,40,5-penta-BDE (BDE-99), 2,20,4,40,5,50-hexa-BDE (BDE-153), and2,20,4,40,6-penta-BDE (BDE-100)) and another brominatedflame retardant (2,20,4,40,5,50hexabromobiphenyl (HBB)) wereon the UCMR-2 in the U.S., and national occurrence data arenow available (http://water.epa.gov/lawsregs/rulesregs/sdwa/ucmr/data.cfm#ucmr2010).
Many review articles have been published on brominatedflame retardants, and one is highlighted here. Wang and Lisummarized the applications of mass spectrometry for theanalysis of PBDEs.193 GC/negative chemical ionization (NCI)-MS, GC/high resolution-MS, and GC/ion trap-MS are the mostcommonly used MS techniques, and newer techniques, such asfast tandem-GC/MS and LC/MS, have improved the analysis forhigher molecular weight PBDEs. Nice summary tables areprovided for measurements of PBDEs in different environmentalmatrixes, including fish, marine mammals, wildlife and domesticanimals, sediment, water, air, soil, and plants. The authors alsodiscuss transport and transformation of PBDEs in the environ-ment, along with metabolism, toxicity, and uptake.
Fascinating studies in biota continue to be published. Forexample, Ragland measured PBDEs in loggerhead sea turtles offthe coast of Florida.194 Blood was sampled from the dorsocervi-cal sinus of each turtle and analyzed by GC/MS for PBDEs andother contaminants. Blood plasma levels for total PBDEs wereelevated and were sometimes correlated with the size of theturtle. Migratory adult turtles showed an atypical congenerprofile relative to profiles in other wildlife. BDE-154 was the
dominant congener. Results suggested an effect of foraginglocation on levels and patterns.
White stork eggs were the focus of a study by Munoz-Arnanzet al., who measured PBDEs in eggs from a rural and urban storkcolony in Spain.195 Total PBDE levels averaged 1.64 ng/g (wetweight) for the rural colony and 9.08 ng/g (wet weight) for theurban colony. BDE-209 was the dominant congener, accountingfor 44% and 39% of the total PBDE content, respectively, andBDE-202, which is an indicator of BDE-209 debromination, wasdetected in 83% of the samples. The congener profile of BDE-207 > BDE-208 > BDE-206 did not mirror any known technicalPBDE mixture and provided evidence for BDE-209 degradation.
Oysters and mussels were the focus of a study by Ueno et al.,who examined the spatial distribution of PBDEs, hexabromocy-clododecanes (HBCDs), and other contaminants in bivalvesfrom the coast of Japan.196 HBCDs were found up to 5200 ng/g(lipid weight), and PBDEs were found up to 86 ng/g (lipidweight). No differences were seen in bioaccumulation betweenoysters and mussels, indicating that oysters could be used as analternative species to mussels for examining bioaccumulation.Estimated dietary exposure through consumption of seafood was0.45�34 ng/kg body weight per day, which was ∼1000� lowerthan the lowest observed effect level.
Honey was the focus of an extensive study byWang et al., whomeasured 27 PBDEs in 50 honey samples originating fromdifferent parts of the world.197 Concentrations of BDE-209ranged from nondetect to 9260 pg/g, while the other 26 PBDEsranged from 300 to 10 550 pg/g. Honey samples from developedcountries generally had higher levels than developing countries.BDE-209 was the dominant congener in all honey samples,accounting for 16% and 65% of the total PBDE concentration inhoney from developed and developing countries, respectively.These findings were consistent with a long, historical use ofPBDE-containing products in developed countries and a current,heavy use of BDE-209 in developing countries. Findings alsoindicate a source of human exposure through consumptionof honey.
Fish oil was examined by Ortiz et al. for HBCDs.198 Con-centrations ranged from 0.09 to 27 ng/g, and specific enantio-mers and diastereomers were also determined. HBCD levelswere similar to other pollutants and correlated with dioxin andPCBs. Dietary intake was estimated at 0.08 to 5.38 ng per day.
Air samples near a municipal solid waste incinerator were thefocus of another study by Wang et al.199 GC/high resolution-MSwith isotope dilution was used for measuring 30 PBDEs andother contaminants. Total PBDE levels ranged from 25.7 to 100pg N/m3 in these samples from Taiwan, which were similar tolevels reported in urban air from North America and Japan.
New methods developed included those using LC/APPI/MS/MS and GC/MS. Zhou et al. developed a new LC/APPI-MS/MS method for measuring PBDEs and other halogenatedflame retardants in fish.200 The analytes eluted within 14 min,with detection limits of 4.7 pg. Good agreement was foundbetween results from this method and from GC/high resolution-MS. Gonzalez-Gago et al. reported a new GC/MS method usingsynthesized 81Br-labeled standards for measuring PBDEs in fishand other solid samples.201 Low limits of detection (0.02 to 0.9ng/g) could be achieved. It is also possible to use this procedurewith evenmore sensitive GC/NCI-MS analyses, which cannot bedone with more common 13C-labeled standards. Finally, Luptonet al., created a new LC/APPI-MS/MS method for measuringhydroxylated PBDE metabolites.202 This method alleviates the
need for derivatization used with current GC/MS techniques andwas demonstrated for the analysis of BDE-47 and -99 in humanliver microsomes.
’BENZOTRIAZOLES
Benzotriazoles are complexing agents that are widely used asanticorrosives (e.g., in engine coolants, aircraft deicers, or anti-freeze liquids) and for silver protection in dish washing liquids.The two common forms, benzotriazole (1H-benzotriazole) andtolyltriazole (a mixture of 4- and 5-methyl-1H-benzotriazole),are soluble in water, resistant to biodegradation, and onlypartially removed in wastewater treatment. There is also newevidence for estrogenic effects in vitro but, so far, not in vivo, inrecent fish studies.1 There is also some evidence that benzotria-zole may be a human carcinogen, and Australia now has adrinking water guideline limit of 7 ng/L for tolyltriazole.203
Because of their water solubility, LC/MS and LC/MS/MSmethods have been recently developed for their measurementin environmental waters. While reports of benzotriazoles arefairly recent (∼last 8 years), studies indicate that they are likelyubiquitous environmental contaminants.
Janna et al. reported an interesting study entitled, “Fromdishwasher to tap? Xenobiotic substances benzotriazole andtolyltriazole in the environment”.203 This study demonstratedtheir presence in UK wastewaters, rivers, and drinking water andsuggested that their use as silver polishing agents in dishwashertablets and powders may account for a significant proportion ofinputs to wastewaters. Benzotriazole and tolyltriazole ranged from840 to 3605 ng/L and 2685�5700 ng/L, respectively, in sewageeffluents and from 0.6 to 79.4 ng/L and <0.5 to 69.8 ng/L,respectively, in drinking water. More effective removal of tolyl-triazole by activated carbon was suggested as the reason for itslower levels in finished drinking water vs river water. Also, in thepan-European study mentioned earlier by Loos et al., 1H-benzo-triazole and methylbenzotriazole were found in >50% of thegroundwaters sampled, up to 1.03 and 0.52 μg/L, respectively.107
New methods include those developed for benzotriazole UVstabilizers in biota. Kim et al. created a new multiresidue methodusing UPLC/MS/MS to measure benzotriazole UV stabilizers andother contaminants in fish.204Method detection limits ranged from0.0002 to 0.009 ng/g for the 8 benzotriazoles measured. Thesewere subsequently found in fish from the coast of the Philippines,up to 179 ng/g for 2-(2H-benzotriazol-2-yl)-4,6-di-tert-pentylphe-nol (UV-328). Nakata et al. developed a new GC/high resolution-MS method for measuring benzotriazole UV stabilizers in theblubber of porpoises.205Mean concentrations were 38 and 19 ng/gfor UV-328 and 2,4-di-tert-butyl-6-(5-chloro-2H-benzotriazol-2-yl)phenol (UV-327) in porpoises from the coast of Japan. Thebioconcentration factor was 33 300 forUV-327, whichwas an orderof magnitude higher than for fish found in the same region.
A newmethod for indoor dust was created byCarpinteiro et al,who used pressurized solvent extraction followed by GC/MS/MS to measure benzotriazole UV stabilizers.206 Limits of quan-tification below 10 ng/g could be achieved, and this methodallowed the first detection of 4 benzotriazole UV stabilizers indust from indoor environments. Mean concentrations rangedfrom 71 to 780 ng/g. Headspace-SPME-GC/MS was used inanother method by Carpinteiro et al. for measuring 5 benzo-triazole UV stabilizers in environmental waters.207 Limits ofquantification below 2 ng/L could be achieved, and this methodwas demonstrated on raw wastewaters.
’DIOXANE
1,4-Dioxane is a widespread industrial contaminant in environ-mental waters (often exceeding water quality criteria and guide-lines), has also been found in drinking water, and is a probablehuman carcinogen. Dioxane is a high production chemical and isused as a solvent stabilizer in the manufacture and processing ofpaper, cotton, textile products, automotive coolants, cosmetics,and shampoos, as well as a stabilizer in 1,1,1-trichloroethane(TCA), a popular degreasing solvent. In 2002, more than 500 tof dioxane were produced or imported in the United States. TheU.S. EPA has identified dioxane as a high priority contaminant, andit is currently listed on the new CCL-3 (http://water.epa.gov/scitech/drinkingwater/dws/ccl/ccl3.cfm). There is also an EPAMethod (522) for its measurement (www.epa.gov/microbes/Method%20522_final%20for%20OGWDW%2009_22_08.pdf).Dioxane is problematic to extract and measure because it ismiscible with water. It is also difficult to remove from water byair stripping or carbon adsorption.
Environmental investigation and remediation of dioxane andother solvent stabilizers was the focus of a new book by Mohr.208
This book included a discussion of the chemistry, uses, andoccurrence; environmental fate and transport; sampling andanalysis; toxicology; regulation and risk assessment; remediationtechnologies; case studies of releases, treatment, and drinkingwater contamination; and forensic applications. Ramirez et al.developed a thermal desorption-GC/MS multiresidue methodfor measuring dioxane and 98 other contaminants in air emis-sions from an industrial wastewater plant.209 This method wasrapid and did not require the use of organic solvents. Detectionlimits of 1.33 μg/m3 were possible, and dioxane was found up to105 μg/m3 in air from one of the two sites sampled.
’SILOXANES
Siloxanes have become a relatively new area of research. Theyinclude cyclic siloxanes, octamethylcyclotetrasiloxane (D4), dec-amethylcyclopentasiloxane (D5), dodecamethylcyclohexasilox-ane (D6), and tetradecamethylcycloheptasiloxane (D7), andlinear siloxanes, which are used in a number of products, such ascosmetics, deodorants, soaps, hair conditioners, hair dyes, carwaxes, baby pacifiers, cookware, cleaners, furniture polishes, andwater-repellent windshield coatings. There is concern aboutpotential toxicity and transport into the environment. They havebeen previously measured in wastewater, river water, and landfillbiogases.1,2 In a new study, Sparham reported the first measure-ments of D5 in river and estuarine sediments in the UK.210 Twoextraction methods were used with GC/MS for measurement.Accelerated solvent extraction (ASE) was useful for measuringthe higher concentrations in river sediments (up to 1450 ng/g insediments from the Great Ouse River), and liquid�solid extrac-tion was useful for lower concentrations found in the estuarinesediments (up to 256 ng/g in the Humber estuary). Limits ofquantification of 57�110 ng/g and 4 ng/g were possible usingASE and liquid�solid extraction, respectively.
’NAPHTHENIC ACIDS
Naphthenic acids (NAs) are a complex mixture of alkyl-substituted acyclic and cyclo-aliphatic carboxylic acids that dis-solve in water at neutral or alkaline pH and have surfactant-likeproperties. They occur naturally in crude oil deposits across theworld (up to 4% by weight) and have also been recently
discovered in coal, which could be a source of contamination forgroundwater. NAs are toxic to aquatic organisms, includingphytoplankton, daphnia, fish, and mammals and are also endo-crine disrupting. With decreased conventional crude oil re-sources, it has become economically feasible to extract heavieroils from oil sand deposits. One of the world’s largest accumula-tion of oil sands occurs in North and South America. Venezuelanoil sand deposits contain the largest known petroleum deposits inthe world, and the Athabasca oil sands in Alberta, Canada, are aclose second.211 The Athabasca oil sands represents more than25% of Canada’s annual oil production, and most research onNAs has been conducted in this region. Caustic hot water is usedin the extraction of crude oil from oil-sands, which results in aresidual tailing water (0.1 to 0.2 m3 of tailings per ton of oil-sandsprocessed) that contains high levels of NAs (80 to 120 mg/Llevels are common) and is very toxic. The total volume of tailingponds is projected to exceed 109 m by the year 2020.
Whitby published a very nice review on microbial napthenicacid degradation, which included a discussion of chemical proper-ties, toxicity, sources, and environmental contamination.211 Bio-degradation studies included those carried out on modelcompounds and commercial NAs, as well as actual environmentaldegradation. Bioremediation methods were also discussed.
New methods continue to be developed, including one byRowland et al., which used GCxGC/TOF-MS to identify in-dividual tetra- and pentacyclic NAs in oil sands process water.212
Headley et al. evaluated the potential of negative ion-ESI-Fouriertransform ion cyclotron resonance (FTICR)-MS for comparingpolar organics (including NAs) from tailing ponds, interceptorwells, groundwater, rivers, and lake water.213 This work was doneto expand investigations beyond NAs because aquatic toxicityand environmental chemistry are attributed to the total organics,not only to the NAs. The ratios of species containing oxygen andnitrogen were useful for differentiating organics derived from oilsands process water from those found in river and lake waters.
New fate studies have also been conducted, including one byHeadley et al. who investigated the degradation of NAs with UV/TiO2 and microwave radiation.
214 A higher oxygen content wasobserved in the treated samples using FTICR-MS, consistentwith oxidation of the parent acids. Microbial degradation was thefocus of another controlled laboratory study by Johnson et al.,who found that degradation was affected by the degree of alkylside-chain branching.215 Degradation products were generallyless toxic than the parent compounds. In each case, biodegrada-tion of the carboxyl side chain proceeded through beta-oxidation.Oxidation pathways were proposed.
Rowland et al. reported the synthesis and characterization of 6alkylcyclohexylethanoic NAs, which had been tentatively identi-fied as biodegradation transformation products.216 GC/MS wasused to characterize their trimethylsilyl derivatives, and toxicityresults showed lower relative toxicity of these transformationproducts relative to the parent NAs.
Finally, an interesting new study by Hersikorn and Smitsinvestigated the effect of tailing ponds (containing NAs) onwood frogs.217 Time to metamorphosis, thyroid hormone status,and detoxification enzyme induction were measured in tadpolesraised in reclaimed oil-sands wetlands and were compared totadpoles raised on control (nonimpacted) wetlands. Metamor-phosis was delayed or never occurred in tadpoles raised in youngtailings (e7 years old), but no effects were seen for tadpolesraised in older tailings. This suggests that tailings wetlandsbecome less toxic with age.
’MUSKS
Synthetic musk compounds are widely used as fragrance addi-tives in many consumer products, including perfumes, lotions,sunscreens, deodorants, and laundry detergents. They can havenitroaromatic structures, as in the case of musk xylene (1-tert-butyl-3,5-dimethyl-2,4,6-trinitrobenzene) or musk ketone (4-tert-butyl-2,6-dimethyl-3,5-dinitroacetophenone), or polycyclic structures, asin the case of 7-acetyl-1,1,3,4,4,6-hexamethyl-1,2,3,4-tetrahydro-naphthalene (AHTN; trade name, tonalide) or 1,3,4,6,7,8-hexahy-dro-4,6,6,7,8,8-hexamethylcyclopenta-(g)-2-benzopyran (HHCB;trade name, galaxolide). Because they are widely present inenvironmental samples, including wildlife and humans, there isgrowing concern. Musks are highly lipophilic, so they tend toaccumulate in sediments, sludges, and biota. Up to 190 ng/g lipidhas been reported in humans.2
Several new methods have been recently developed formeasuring musks. Lung and Liu created a new UPLC/APPI-MS/MS method for measuring 6 musks.218 Chromatographicseparation could be achieved in 7 min in the positive ion modeand 5.1 min in the negative ion mode. Limits of detection werebelow 6 pg. Hu and Zhou compared microwave-assisted extrac-tion, simultaneous distillation-solvent extraction, Soxhlet extrac-tion, and ultrasound extraction for extracting polycyclic musksfrom sediments and other environmental samples.219 Micro-wave-assisted extraction and ultrasound extraction were found tobe the most effective. This method was subsequently used tomeasure the uptake of musks in wheat plants, which correlatedsignificantly to concentrations found in the sediments.
Sapozhnikova et al. used ASE with gel permeation chroma-tography/SPE cleanup and GC/MS to measure musks in sedi-ments and shrimp.220 HHCB was detected in all shrimpmeasured, with levels of 48 to 683 ng/g lipid in farmed shrimpand 66 to 762 ng/g in wild shrimp, revealing very similar levelsand widespread distribution. Sediment collected from 3 regionsof the Chesapeake Bay showed HHCB up to 9.2 ng/g (dryweight). Finally, Reiner and Kannan measured polycyclic musksin river water, sediment, fish, and mussels from the UpperHudson River, New York.221 HHCB and AHTN were foundin river water (up to 25.8 ng/L), sediment (up to 544 ng/g dryweight), fish (up to 125 ng/g lipid weight), and zebra mussels(up to 65.9 ng/g lipid weight). Bioaccumulation factors ofHHCB calculated for white perch, catfish, smallmouth bass,and largemouth bass ranged from 18 to 371 (on a wet weightbasis) and 261 to 12 900 (on a lipid weight basis).
’PESTICIDE TRANSFORMATION PRODUCTS
Herbicides and pesticides continue to be the focus of muchenvironmental research. Recent studies have focused more ontheir transformation products because their hydrolysis, oxida-tion, biodegradation, or photolysis transformation products canbe present at greater levels in the environment than the parentpesticide and can be as toxic or more toxic. Several pesticidedegradation products are on the U.S. EPA’s new CCL-3: alachlorethanesulfonic acid (ESA), alachlor oxanilic acid (OA), aceto-chlor ESA, acetochlor OA, metolachlor ESA, metolachlor OA,3-hydroxycarbofuran, and terbufos sulfone (http://water.epa.gov/scitech/drinkingwater/dws/ccl/ccl3.cfm), as well as onthe UCMR-2 (alachlor ESA and OA, acetochlor ESA and OA,and metolachlor ESA and OA).
LC/MS and LC/MS/MS are now common-place for measur-ing pesticide degradates, which are generally more polar than the
parent pesticides, making LC/MS ideal for their detection. Inaddition, researchers are increasingly using UPLC to enablesimultaneous analysis of larger groups of pesticides and theirdegradation products, and TOF-MS and Q-TOF-MS are beingused to identify new pesticide degradates.
Botitsi et al. published a comprehensive review of MS strategiesfor analyzing pesticides and their metabolites in food and watermatrixes.222 Sample preparation techniques included the QuE-ChERS (Quick, Easy, Cheap, Effective, Rugged, Safe) approach,and various methods using UPLC and LC/MS/MS are nicelysummarized. Methods include those applied to fruits, vegetables,milk, meat, eggs, honey, flour, rice, grains, baby foods, cereals, fruitjuices, soft drinks, olive oil, wines, and other alcoholic beverages.
Durand et al. used NMR, LC/NMR, and LC/MS as com-plementary techniques to investigate the biodegradation path-ways of the herbicide mesotrione.223 The use of LC/NMRenabled the unambiguous identification of 6 metabolites,whereas only 4 metabolites were suggested by LC/MS. Inaddition, NMR was able to uncover a new metabolic pathway.Degradation mechanisms of the pesticide phoxim was the focusof another study by Lin et al., who used LC/MS/MS to identifythe transformation products.224 Results showed a first-orderdegradation. UV irradiation and increased pH and temperatureaccelerated the degradation. Five intermediates were identified,and degradation pathways were proposed. Hydrolysis productsof the pesticide dyfonate were the focus of another study byWang et al., who used GC/MS to identify the transformationproducts, thiophenol and phenyl disulfide.225 Hydrolytic path-ways were also proposed.
Kern et al. compared model predictions to actual field data for16 pesticides and 46 transformation products (TPs) measured ina small river draining an agricultural catchment in Switzerland.226
Twenty TPs were measured quantitatively using SPE-LC/MS/MS, and the remaining 26 were detected qualitatively, due to thelack of reference standards. Comparison of predicted andmeasured exposure ratios for 20 pairs of TPs and parentpesticides showed agreement within a factor of 10, except forchloridazon desphenyl and chloridazon-methyl-desphenyl,which were found at elevated levels during baseflow conditionsand in groundwaters across Switzerland. A model-based ap-proach was proposed to identify TPs that exhibit a high aquaticexposure potential.
Helbling et al. published a new high-throughput procedure forthe elucidation of TPs for a broad and diverse group ofpesticides.93 Samples coming from batch reactors seeded withactivated sludge were separated by LC and analyzed by linear iontrap-Orbitrap-MS. TPs were tentatively identified using a post-acquisition data processing method, which was based on targetand nontarget screening of full-scanMS data, and structures wereproposed by interpretation of MS/MS fragments. Using thisprocedure, new microbial TPs were reported. Results showedthat the complementary use of target and nontarget screeningallowed for more comprehensive identification of TPs. UPLC-MS/MS was used by Benvenuto et al. for a new method tosimultaneously determine triazine and its TPs in surface waterand wastewaters.227 Confirmation of identity was achieved byacquiring 3 selected reaction monitoring (SRM) transitions andmatching ion ratios, which was possible down to 0.025 μg/L.
Finally, in the pan-European survey mentioned earlier by Looset al., pesticide transformation products were included and wereamong the most frequently detected and highest concentrationof the many analytes measured in European groundwaters.107
For example, desethylatrazine and desethylterbutylazine werefound in 55% and 49% of the samples, up to 487 and 266 ng/L,respectively.
’PERCHLORATE
Perchlorate became an important environmental contaminantfollowing its discovery in a number of water supplies in thewestern United States. It has since been found in environmentalwaters across the United States and in other parts of the world atμg/L levels, as well as in fresh produce, foods, wines, andbeverages from many countries, including those in Europe andthe Far East. Perchlorate has also been found in biologicalsamples, and it can be transported by pregnant mothers to theirdeveloping babies across the placental barrier. Perchlorate isincreasingly being found in environmental waters followingfireworks displays. As a result, it is now recognized as a worldwideenvironmental issue, rather than only being limited to the UnitedStates. Ammonium perchlorate has been used in solid propel-lants used for rockets, missiles, and fireworks, as well as highwayflares. There is also potential contamination from fertilizers (e.g.,Chilean nitrate, where perchlorate co-occurs naturally), and newwork has revealed other natural sources of perchlorate. Inaddition, perchlorate can be a contaminant in sodium hypo-chlorite (liquid bleach) that is used in drinking water treatment.Perchlorate is an anion that is very water-soluble and environ-mentally stable. It can accumulate in plants (including lettuce,wheat, and alfalfa), which can contribute to exposure in humansand animals. In addition, perchlorate is not removed by conven-tional water treatment processes, so human exposure can alsooccur through drinking water. Health concerns arise fromperchlorate’s ability to displace iodide in the thyroid gland, whichcan affect metabolism, growth, and development.
Due to these concerns and due to the proportion of the U.S.population exposed to it, theU.S. EPA has now decided to regulateperchlorate under the Safe DrinkingWater Act (http://water.epa.gov/drink/contaminants/unregulated/perchlorate.cfm). The reg-ulation is currently being developed, and there is not a proposedmaximum contaminant level (MCL) as of yet. Perchlorate waspreviously on the U.S. EPA’s earlier CCL lists (CCL-1 andCCL-2) and is now on the CCL-3. (http://water.epa.gov/scitech/drinkingwater/dws/ccl/ccl3.cfm). Perchlorate was alsoincluded in the first UCMR (http://water.epa.gov/lawsregs/rulesregs/sdwa/ucmr/data.cfm). The U.S. EPA established areference dose of 0.0007mg/kg/day, which translates to a drinkingwater equivalent level (DWEL) of 24.5 μg/L.1 Prior to thisdecision to regulate on a national basis, California had alreadyissued a state regulation of 6 μg/L (in 2007) (www.cdph.ca.gov/certlic/drinkingwater/Pages/Perchlorate.aspx), and several stateshad issued advisory levels, ranging from 1 to 18 μg/L (www.epa.gov/fedfac/documents/perchlorate_links.htm#state_adv). Thereare several EPA Methods for measuring perchlorate in water,including EPAMethod 314.2 (2-dimensional ion chromatography(IC) with suppressed conductivity detection), EPA Method 331(LC/ESI-MS/MS), and EPA Method 332 (IC/ESI-MS/MS).(www.epa.gov/safewater/methods/analyticalmethods_ogwdw.html; www.epa.gov/nerlcwww/ordmeth.htm).
English et al. published an intriguing study of perchlorateexposure biomarkers in a highly exposed human population.228
Perchlorate contamination is particularly high in the LowerColorado River, which serves as the sole source of irrigationwater for California’s Imperial Valley and can be an important
source of exposure to people living in this region. Urine wasmeasured from people consuming locally grown produce in thisregion, as well as their drinking water and local produce. All buttwo of the water samples tested negative for perchlorate, but itwas detected up to 1816 ppb in produce. Estimated doses rangedfrom 0.02 to 0.51 μg/kg body weight/day. The geometric meanwas 70% higher than for the reference population. Although noneof the exposures exceeded the U.S. EPA reference dose, 3participants exceeded the acceptable daily dose used by theCalifornia Office of Environmental Health Hazard Assessment.
Recent studies address perchlorate occurrence in drinkingwater. For example, Blount et al. investigated perchlorate, nitrate,and iodide intake through direct and indirect consumption of tapwater.229 Median perchlorate levels measured in tap water were1.16 μg/L, which were below the U.S. EPA’s DWEL of 24.5 μg/L.Significant correlations were found between perchlorate andnitrate. Using individual tap water consumption data and bodyweight, the median perchlorate dose attributable to tap water was9.11 ng/kg-day. In another study,Wu et al. measured perchloratein tap water, groundwater, surface waters, and bottled water fromChina.230 LC/MS/MS was used for measurement. Perchloratewas detected in 86% of the samples, with mean levels of 2.5, 3.0,2.8, and 0.22 μg/L in tap water, groundwater, surface water, andbottled water, respectively.
Infant formula was the focus of another study by Schier et al.,who measured perchlorate in commercially available powderedinfant formulas.231 Levels ranged up to 5.1 μg/L (bovine-basedmilk), 0.44 μg/L (soy-basedmilk), 0.93 μg/L (lactose-free milk),and 0.4 μg/L (“elemental milk”, consisting of amino acids).Results showed that the perchlorate reference dose can beexceeded when certain bovine-based milk formulas are ingestedor when powdered infant formulas are reconstituted with per-chlorate-contaminated water.
Soybean sprouts, lotus root, and water dropwort were thefocus of another perchlorate uptake study by Yang and Her inSouth Korea.232 IC/MS/MS was used for measurement. Per-chlorate was detected in 91% of the soybean samples, up to 78.4μg/kg dry weight. The highest perchlorate level in lotus root was17.3 μg/kg and for water dropwort was 39.9 μg/kg.
Jackson et al. evaluated the isotopic composition of naturalperchlorate in the southwestern U.S. to understand its origins.233
Stable isotope ratios were measured for perchlorate (δ18O,Δ17O,δ37Cl) and associated nitrate in groundwater from the southernHigh Plains of Texas and New Mexico, the Middle Rio GrandeBasin in New Mexico, unsaturated subsoil in the southern HighPlains, and nitrate-rich deposits near Death Valley, California.Natural perchlorate in the southwestern U.S. displayed a widerange of isotopic compositions that are distinct from thosereported previously from the Atacama Desert of Chile or forsynthetic perchlorate. Death Valley samples indicated partialatmospheric formation via reaction with ozone. In contrast,perchlorate isotope ratios from western Texas and New Mexicoindicated that they were affected by postdepositional oxygenisotope exchange. This study provides important new informationon the possibility of divergent perchlorate formation mechanismsand isotopic exchange in biologically active environments.
’ALGAL TOXINS
Algal toxins (mostly cyanobacterial toxins produced fromblue-green algae) are of increasing interest in the United Statesand in other countries around the world. Increased discharges of
nutrients (from agricultural runoff and wastewater discharges)have led to increased algal blooms and an accompanyingincreased incidence of shellfish poisoning, large fish kills, anddeaths of livestock and wildlife, as well as illness and death inhumans. Toxins produced by these algae have been implicated inthe adverse effects.
The most commonly occurring algal toxins are microcystins,nodularins, anatoxins, cylindrospermopsin, and saxitoxins. “Redtide” toxins are also often found in coastal waters. Microcystinsand nodularins are hepatotoxic high molecular weight, cyclicpeptide structures. Anatoxins, cylindrospermopsin, and saxitox-ins are heterocyclic alkaloids; anatoxins and saxitoxins areneurotoxic, and cylindrospermopsin is hepatotoxic. “Red tide”toxins include brevetoxins, which have heterocyclic polyetherstructures and are neurotoxic. Microcystins (of which, more than70 different variants have been isolated and characterized) are themost frequently reported of the algal toxins.
The most common microcystins are cyclic heptapeptides thatcontain the amino acids leucine and arginine in their structures.Nearly every part of the world that uses surface water as a drinkingwater source has encountered problems with cyanobacteria andtheir toxins. Algal toxins were on the U.S. EPA’s previous CCLs(CCL-1 and CCL-2) in a general way, “cyanobacteria (blue-greenalgae, other freshwater algae, and their toxins”, and now, the CCL-3 has specifically named three cyanobacterial toxins: anatoxin-a,microcystin-LR, and cylindrospermopsin for the new list (http://water.epa.gov/scitech/drinkingwater/dws/ccl/ccl3.cfm). Severalcountries, including Australia, Brazil, Canada, France, Italy, Po-land, and New Zealand, have guideline values for microcystins,anatoxin-a, and cylindrospermopsin (ranging from1.0 to 1.5μg/L).Many of these toxins have relatively high molecular weights andare highly polar.
In 2010, a special issue of the journal Toxicon, on “HarmfulAlgal Blooms and Natural Toxins in Fresh and Marine Waters”included 14 papers on the exposure, occurrence, detection,toxicity, control, management, and policy.234 This issue is amust-read for the latest state-of-the science for algae and theirtoxins. Dorr et al. reviewed the occurrence, toxicity, and toxico-logical assays for microcystins in South American aquaticecosystems.235 The acute poisoning of patients receiving hemo-dialysis in 1996 in Brazil was highlighted as the catalyst for thediscovery of microcystins in South America.
A dog poisoning in New Zealand was the focus of aninvestigation by Wood et al., who found microcystin-LR andother variants to be responsible.236 This was the first report of abenthic microcystin-producing species causing an animal deathin New Zealand. LC/MS was used to measure the microcystins;no cylindrospermopsin, saxitoxins, or anatoxins were detected.
Berry et al. examined the bioaccumulation of microcystins infish following a cyanobacterial bloom in Mexico.237 Fish wereobtained from local markets and small commercial catchesduring the bloom. LC/MS was used for measurement. All threespecies of fish bioaccumulated the microcystins, and toxincontent correlated with trophic level. Detection in silversidesand Goodea species was particularly relevant because both areconsumed in their entirety, including the livers, which accumu-late the microcystins.
New methods continue to be developed for algal toxins. Forexample, Li et al. reported a new LC/ESI-MS/MS method formeasuring the neurotoxin beta-N-methylamino-L-alanine(BMAA) in cyanobacterial isolates.238 Detection limits of 2 pgcould be achieved. A new solid phase adsorption toxin tracking
method called SPATT was created by Wood et al. to measureanatoxin-a and homoanatoxin-a in river water.239 Fifteen differ-ent adsorption substrates were screened for integrated, in situextraction. Nine of the sorbents retained anatoxin-a at >70%,with powdered activated carbon (PAC) and Strata-X the bestphases for the extraction bags. A 3-day field study in a rivercontaining toxic benthic cyanobacterial mats was undertakenusing PAC and Strata-X SPATT bags. Anatoxin-a and homo-anatoxin-a were detected in all SPATT bags, whereas surface grabsamples only allowed detection of these toxins in one of thesamples collected.
Ionic-liquid supported cloud point extraction was used forextracting microcystin-LR from water in a new method byPavagadhi et al.240 1-Butyl-3-methylimidazolium hexafluorophos-phate was used as the ionic liquid, and detection limits of 0.03μg/L could be achieved. This method was subsequently testedon waters from reservoirs.
Deleuze et al. created a new MALDI-TOF-MS method formicrocystins.241 This method utilizes the reductive propertiesof the matrix 1,5-diaminonaphthalene, which can selectivelyreduce the carbon�carbon double bond of the seventh aminoacid. A new UPLC/MS/MS method was created by Oehrleet al. for measuring the CCL cyanotoxins (microcystin-LR,anatoxin-a, and cylindrospermopsin) in a single analysis, in lessthan 8 min.242
’MICROORGANISMS
Outbreaks of waterborne illness in the United States and otherparts of the world have necessitated improved analytical methodsfor detecting and identifying microorganisms in water and otherenvironmental samples. Several microorganisms are included onthe new CCL-3 (http://water.epa.gov/scitech/drinkingwater/dws/ccl/ccl3.cfm). The U.S. EPA’s National Exposure ResearchLaboratory in Cincinnati has developed several methods formeasuring microorganisms in water (www.epa.gov/nerlcwww).These include methods for Cryptosporidium, Giardia, E. coli,Aeromonas, coliphages, viruses, total coliforms, and enterococci.E. coli O157:H7 and H1N1 (swine flu) have captured a lot ofattention recently because they have caused a number of out-breaks and deaths around the world. Traditional biologicalmethods are often used for detection of microorganisms, includ-ing cell culture, immunological methods, polymerase chainreaction (PCR), and microscopic identification, but ESI andMALDI-MS methods are also often used.
In a new review article, Sauer and Kliem outlined massspectrometry tools for classifying and identifying bacteria.243
Seng et al. reviewed the use of MALDI-TOF-MS techniques foridentifying microorganisms.244 In another review, Schneider andRiedel trace the historical development of environmental pro-teomics and summarize milestone developments for analyzingthe structure and function of microbial communities.245
New methods include one by Whitehouse et al., who usedPCR with ESI-MS to identify pathogenic Vibrio species in theaquatic environment of the former Soviet Republic of Georgia.246
Using this method, 9 different Vibrio species were detected in41% of the 248 water samples collected in freshwater lakes. Top-down proteomics was used in another method by Wynne et al.for measuring bacteria with capillary-LC/Orbitrap-MS/MS.247
Using this method, not only were the representative proteinsidentified but also the target bacteria could also be placed in theircorrect phylogeny. In addition, this method provided strong
experimental evidence for correct, missing, and misannotatedbacterial protein sequences. Fenselau et al. created a microwave-assisted acid cleavage method to improve the detection of humanadenovirus by MALDI-MS.248 With this method, denaturizationand proteolysis could be done in a single reaction and allowedpeptide products to be profiled in <5 min. A new top-downproteomics MALDI-MS method was also developed by Fager-quist et al. for measuring E. coli O157:H7.249 In this method, 6protein biomarkers from two strains of E. coli O157:H7 and onenonpathogenic strain of E. coli could be identified. New web-based software developed allowed the comparison of fragmentions to those predicted in silico. While it was not possible todistinguish E. coli O157:H7 from E. coli O55:H7, it was possibleto distinguish it from the nonpathogenic form.
Gaia et al. created a new MALDI-MS method for the rapididentification of Legionella.250 Using 453 Legionella isolatespreviously characterized by genotyping, species-specific “Super-Spectra” were used to aid in the identification. With this method,99% of the tested strains isolated from the environment could becorrectly identified.
Gold nanoparticle labeling was used with ICPMS in a newmethod by Li et al. to measure E. coli O157:H7 in water.251 Thismethod took advantage of the signal amplification property ofgold nanoparticles, monoclonal antibody recognition, and thehigh sensitivity of ICPMS, which enabled the detection of as fewas 500 E. coli O157:H7 cells in a 1 mL sample. Specificity wasexcellent, as nonpathogenic forms of E. coli did not bind oradsorb to the antibody-conjugated gold nanoparticles, and testswith these showed only background signals equivalent to theblanks. The specificity of this assay is due to the specificantibodies used for E. coli O157:H7. The assay was also veryrapid, requiring only 40 min. Because of the ability of ICPMS todetect a wide range of elements, the applicability of this tech-nique could be extended to other nanoparticles (including silverand rare earth nanoparticles) and potentially used in a highthroughput capacity to enable multiple bacterial cells to bemeasured simultaneously, through the use of different antibodiesfor different cells.
’BIOGRAPHY
Susan D. Richardson is a research chemist at the U.S.Environmental Protection Agency’s National Exposure ResearchLaboratory in Athens, GA. She received her B.S. degree inChemistry and Mathematics from Georgia College in 1984 andher Ph.D. degree in Chemistry from Emory University in 1989.Her research has focused on the identification, characterization,and quantification of new toxicologically important disinfectionbyproducts (DBPs), with special emphasis on alternative disin-fectants and polar byproducts. She is particularly interested inpromoting new health effects research so that the risks of DBPscan be determined and minimized.
’ACKNOWLEDGMENT
I would like to thank Tom Jenkins of the U.S. EPA for helpfulinformation on PFCs, John Sumpter of Brunel University for theincredible presentation he gave recently that alerted me to theissue with the vultures and diclofenac, Sara Castiglioni and EttoreZuccato for a nice, autographed copy of their new book on IllicitDrugs in the Environment, and David Humphries of the AlbertaResearch Council for daily inspiration. I would also like to thank
the researchers of all of these interesting articles I get to read eachyear; they are a great source of learning forme. This paper has beenreviewed in accordance with the U.S. EPA’s peer and adminis-trative review policies and approved for publication. Mention oftrade names or commercial products does not constitute endorse-ment or recommendation for use by the U.S. EPA.
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’NOTE ADDED AFTER ASAP PUBLICATION
This paper was published on the Web on December 6, 2011. Anadditional reference was added (ref 16), and the correctedversion was reposted on January 5, 2012.
