Inside this Issue January 2008 – Issue 33 Agilent ICP-MS Journal 2-3 GC-ICP-MS for Volatile Siloxane Compounds of Importance to the Wastewater Industry 4-5 Rinse Solution for Boron Analysis and Boron Isotope Ratios 6 How to Download ICP-MS ChemStation Software Updates 7 New Torch for 7500 Series ICP-MS, Reduce Pump Noise with Quiet Cover for 7500 ICP-MS, User Testimonials: 7500 Series Carries On following Lab Power Loss 8 Winter Plasma Conference 2008, Agilent Applications Scientist Receives Prestigious Award, 4500 Now EOS, Upcoming Events, New Publications
Transcript
Inside this Issue
January 2008 – Issue 33
Agilent ICP-MS Journal
2-3 GC-ICP-MS for Volatile Siloxane Compounds of Importance tothe Wastewater Industry
4-5 Rinse Solution for Boron Analysis and Boron Isotope Ratios
6 How to Download ICP-MS ChemStation Software Updates
7 New Torch for 7500 Series ICP-MS, Reduce Pump Noise with Quiet Cover for 7500 ICP-MS, User Testimonials: 7500 Series Carries On following Lab Power Loss
8 Winter Plasma Conference 2008, Agilent Applications Scientist Receives Prestigious Award, 4500 Now EOS, Upcoming Events, New Publications
GC-ICP-MS HelpsSolve Biogas UsageProblem Steven WilburAgilent Technologies, USA
Introduction Biogas is the term used to describethe mixture of methane, carbon dioxide, nitrogen and other componentsresulting from the anaerobic fermentation of a variety of bio-degradable materials including animalwaste, domestic sewage sludge andmunicipal landfill waste.
Because of its methane content (40-75%), biogas can be used as a substitute for natural gas and iscommonly used at wastewater treatment plants and landfills forheating, electricity generation, andvehicle fuel. However, as a wastebyproduct, biogas may also includeundesirable components includingvolatile sulfur and halogen containingcompounds, as well as volatile siliconcompounds (siloxanes).
Upon combustion, the sulfur andhalogen compounds can form corrosiveacids and the siloxanes can formabrasive silicon dioxide (silica). Silicondioxide is particularly problematicbecause it accumulates within process equipment, such as boilers,and both reciprocating and turbineengines, causing premature wear andeventual failure. For this reason,levels of volatile siloxanes must becarefully monitored and controlledwhen biogas is used to fuel expensivemachinery.
Analysis of Volatile SiloxanesTraditionally siloxanes in biogas
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have been measured using GC/MS withdetection limits ranging from 0.02 to1 ppmv (parts per million by volume)depending on the specific method.However, as engine technology hasshifted from fairly robust reciprocatingengine usage to cleaner burningmicroturbine usage (Figure 1), thetolerance to siloxanes has decreasedto the point where better analyticalsensitivity is required.
GC-ICP-MS was evaluated for sensitivity, ease of use and robustnessfor siloxanes analysis. While Si analysiscan be challenging by ICP-MS, theAgilent GC interface uses a dryplasma for very high temperature andefficient ionization and significantlyreduced interferences from oxygenand nitrogen based polyatomics.The use of hydrogen reaction modeon the 7500ce further reduces theN2 background on Si to insignificantlevels, resulting is superior sensitivityfor siloxane analysis.
Eight siloxanes, each at approximately45ppb (µg/L) in methanol, wereanalyzed using the Agilent 6890/7500ce GC-ICP-MS system. Totalrun time was less than 10 minutes(Figure 2) and detection limitsbased on twice the peak-peak signalto noise were < 1 pg per compound.When converted to concentrations
in biogas, assuming standard samplecollection techniques, the resultingdetection limits ranged from changeto 0.03 - 0.07 ppbv (parts per billionby volume), which is 100x lowerthan the most stringent enginemanufacturers requirements andmore than 500x more sensitive thanthe lowest reported GC/MS detectionlimit.
Furthermore, since ICP-MS is capableof compound independent calibration,the unavailability of standards forsome compounds is not a problem.Accurate quantification of any volatileSi containing compound can bebased on the response of a singlestandard compound.
The calibration curve shown inFigure 3 was generated using dodecamethylpentasiloxane from4.5 to 90.45 ppb with excellentlinearity (r2 = 1.000). When a standardat 4520 ppb was analyzed against thiscurve, the calculated concentrationwas 4244 ppb (94% recovery) indicating that the method waslinear up to 50 times higher thanthe highest calibration point.
Agilent ICP-MS Journal January 2008 - Issue 33
Figure 1. Microturbine component before and after exposure to biogas containing volatile siloxanes [1]
Compound Abbr. Molecular Formula Molecular Weight Boiling Point (°C)
Table 1. Characteristics of volatile siloxanes commonly found in biogas [2]
3www.agilent.com/chem/icpms Agilent ICP-MS Journal January 2008 - Issue 33
Figure 2. Chromatogram of eight siloxanes at approximately 45 ppb (µg/L) each in methanol analyzed using GC-ICP-MS
Figure 3. Calibration plot of dodecamethylpentasiloxane from 4.5 to 90.45 ppb
ConclusionsVolatile siloxanes pose increasinglysignificant problems for biogas useat wastewater treatment plants andlandfills. As a result, process equipment manufacturers are imposing stricter limits on acceptableconcentrations of Si in biogas. Insome cases, these limits cannot bereliably measured using the currentlyused methodologies. GC-ICP-MScan easily achieve the desireddetection limits, with excellentlinearity, reproducibility and easeof use.
4 Agilent ICP-MS Journal January 2008 - Issue 33 www.agilent.com/chem/icpms
Rinse Solution forBoron Analysis andBoron Isotope Ratios Claire Wright, CSIRO Land and Water,Center for Environmental ContaminationResearch Urrbrae, South Australia
Fred Fryer Agilent Technologies, South Asia
Glenn WoodsAgilent Technologies, UK
Introduction Boron is an essential micronutrientrequired by plants for growth,reproduction and survival.
The bioavailable or labile pool ofboron (the exchangeable fraction)in soil can be estimated using isotopedilution mass spectrometry (IDMS)by measuring the distribution of anadded stable boron isotope (10B)between a soil solution and solidphase over a period of time. Stableboron isotopes are chosen sinceradioactive boron isotopes have ahalf life of < 1 second. IDMS quantification of boron requiresaccurate measurement of bothboron isotopes at mass 10 and 11with enriched 10B added in an unnatural abundance. Interferenceon either isotope must be eliminatedor corrected for. Mass bias, which isstable for a given instrument, canbe compensated for by reference toa standard of known mass ratio.However, bias in the determinationof 11B/10B ratio can also come froma background signal of natural boronretained from a previous sample(poor washout of the sample), orelevation of the 11B signal due to12C. The carbon signal can vary by alarge amount since the carbon levelin soil samples can vary significantly,and the rinsing solutions used maycontain carbon. Retention of boron(memory effect) largely comes from thesample introduction area of the ICP-MSi.e. uptake tubing, spraychamber,nebulizer glassware, torch and theplasma/sample interface. Uptakeperistaltic pump tubing can be avoidedby using a self aspirating or directinjection method but these systemsare either manual or require additionalhardware. The use of specializednebulizers such as direct injectionnebulizers and PFA micro concentric
Alkaline mannitol (Rinse solution3) showed the highest backgroundand was unusable, compared to eitherammonia or mannitol alone. It ishypothesized that the ammonia/mannitol rinse cleans the glass ofboron accumulated over manyyears of analysis, scavenging boronfrom the glass surface. Therefore,while this should have been the bestsolution, background from existingcontamination (even in high purity,boron-free silica) made it unusable.However, the stabilization time was<3 minutes and the washout timewas <5 minutes indicating that withclean glassware, this solution shouldwork well. Agilent rinse solution(Rinse solution 5) - a combinationof ammonia, EDTA, Triton X100and H2O2 provided the lowest boronbackground (<5000 cps) with faststabilizing and washout times (<3minutes to original baseline) – seeFigure 1.
nebulizers have been shown toreduce boron carryover [1] but suchnebulizers can be difficult or costlyto obtain and use.
One of the aims of this work was toestablish a routine, reliable and ruggedmethod for ICP-MS measurement ofboron isotopes that utilizes thestandard sample introduction system.
Boron Memory Effects Various rinse solutions were investigated (Table 1) using the7500ce ICP-MS. Operating parametersare given in Table 2. A 10 minuterinse time was used to establish thebaseline signal of boron for eachrinse solution. Boron standards (10ug/L and 100 ug/L) in 2% HNO3(representative of the expectedboron levels in a digested soil sample)were then introduced for 10 minutesfollowed by a rinse cycle. 10B wasmonitored using time resolved analysis (TRA).
Solution 1 Nitric acid – same as the sample digest chemistry
Solution 2 *Mannitol in water – 0.25% mannitol
Solution 3 *Mannitol in ammonia –0.25% mannitol in 0.1MNH4OH
*Boron readily complexes with polysaccharidesand alcohols and so mannitol (C6H8(OH)6 hasbeen frequently reported for stabilizing and transporting boron through the formation of a stablecomplex.
Rinse Solutions ResultsThe starting baseline was high fornitric acid (Rinse solution 1) andmannitol (Rinse solution 2), and >15 minutes was needed to achievebaseline after sample introduction.Similarly the boron sample signaltook >5 minutes to stabilize.Overall, these methods would take> 25 minutes per sample.
Table 2. 7500ce ICP-MS operating parameters
Figure 1: Response of 10B using the Agilent rinsesolution
5www.agilent.com/chem/icpms Agilent ICP-MS Journal January 2008 - Issue 33
Figure 2: Expanded mass axis scale showing the signal from mass 7 to 12 amu. Note: No overlap ofcarbon peak (m/z 12) on boron (m/z 11).
Carbon Effect on 11B DeterminationsA further aim of the study was toinvestigate the effect of carboninterference on the analysis ofboron. A solution of 1000 mg/Lsucrose in solution with 10 ug/Lboron, beryllium and lithium wasanalyzed by the 7500ce. As Figure 2indicates, there was no overlap ofmass 12 (C) on mass 11 (B).
The effect of varying carbon levelson different boron concentrationswas undertaken by analyzing NISTCRM 951 boric acid (11B = 80.1%abundance, 10B = 19.9% abundance)in varying sucrose concentrations(1000 mg/L sucrose = 421 ppm C).The results presented in Table 2show that there is no effect fromcarbon on 11:10 B ratio even at thelowest boron concentration.
Resources.•Open file: "Rinsing Protocol for
Rapid Measurement of ‘Sticky’ Analytes by 7500 Series ICP-MS"
Potential 12C interference on 11Bsignal was shown not to be apparent.
Eliminating both memory and carboninterference effects, should allowsimple, accurate boron quantificationby isotope dilution ICP-MS.
References1. Ana Cláudia S. Bellato; Amauri A.Menegário; Maria Fernanda Giné,Boron isotope dilution in cellularfractions of coffee leaves evaluatedby ICP-MS with direct injection nebulization, J. Braz. Chem. Soc.vol.14 no.2 São Paulo Mar./Apr.2003.
More InformationFor more details on the Agilentrinse solution (rinse solution 5),please visit the Agilent ICP-MS UserForum.
To access the Forum, you will simplyneed to log-in to the Agilent website, or register if you haven't already,and enter your instrument's serialnumber on your first visit only.
•Go towww.agilent.com/icp/ms
•Look for the User Forum link under Additional Information
•Once in the ICP-MS User Forum, click on Agilent ICP-MS User
Boron ug/L Sucrose mg/L 11/10B
10 0 4.4 ± 0.02
10 10 4.4 ± 0.07
10 100 4.3 ± 0.04
10 500 4.4 ± 0.03
10 1000 4.4 ± 0.02
100 0 4.4 ± 0.004
100 10 4.4 ± 0.03
100 100 4.4 ± 0.02
100 500 4.4 ± 0.02
100 1000 4.4 ± 0.01
Table 2. Carbon effect on boron isotope ratios
ConclusionsAn alkaline rinse solution containingEDTA, hydrogen peroxide and asurfactant was selected as the mostefficient washout procedure for theremoval of memory effects onboron determinations by ICP-MS.The low stable baseline allowed forlower quantification limits forboron (< 1 µg/L) and the samplestabilisation times < 4 min) andwash-out times after sample analysis(< 3 min) were fairly rapid.
6 Agilent ICP-MS Journal January 2008 - Issue 33 www.agilent.com/chem/icpms
How to DownloadICP-MS ChemStationSoftware Updates Tomo YamadaICP-MS Product Manager, Tokyo Analytical Division, Agilent Technologies
Make sure you are getting the mostfrom your 7500 Series ChemStationsoftware by updating to the latestsoftware revisions for bothWindows 2000 and XP operatingsystems.
To check which Product numberand Revision you are using, click on"Help" menu and select "About" inthe ChemStation software.
Updating to the latest revision isimportant – it eliminates any minorfaults that have been identified andfixed in earlier versions, and enablesAgilent field staff to support youmore efficiently.
A list of updates available on-line isgiven in Table 1.
For 7500 Series users with older,NT ChemStation software versions(Rev.A), an upgrade to B.03.06 (O/Snot included) is available to purchaseby ordering P/N G3149B.
Please note that some PCs originallysupplied with older 7500 mainframeswill not meet the requirements forB.03.06 – see Pre-install Notice onthe website. Should a new PC berequired, a new ICP-MS PC hardwareupgrade bundle (G3150A opt.321)is available.
For current rev.B.0x.0x users, a freeupgrade to B.03.04 (for Windows2000 users) or B.03.06 (forWindows XP users) can be downloaded from the Agilent ICP-MSwebsite - see instructions below.
1. Visitwww.agilent.com/chem/icpms
2. Select "ICP-MS Software" locatedin the center column of the page.
3. Select "ICP-MS ChemStationUpdates & Downloads". (To access this page, you will firstneed log in to the Agilent site, orregister if you haven’t done so previously, and then enter the 10digit registration number shown onthe "Software Certificate &Registration Packet" supplied withyour instrument).
4. Click on "ICP-MS ChemStation".
5. To download the relevant patchfile for your ChemStation version,click on the applicable ChemStationupdate.
ChemStation Update from Update to Operating System / Interface FeaturesProduct No.
G1834B B.01.00 B.03.06 Windows XP SP2 / LAN All B.03.04 features plus
– B.03.05 • Support OpenLAB ECM Integration
• Semiquant factors for Helium mode
• Control CETAC EXR-8 Autosampler
G1834B B.01.00 B.03.04 Windows 2000 SP4 • New Tuning Window
– B.03.03 / LAN or GP-IB • System Wide Parameters
• Autotune for three Gas Mode
• Pre-Run Monitor
• Batch View
• Offline Acquisition Editor
• Coexistence with Agilent LC/GC
ChemStation (English)
• Pre-emptive rinse support
• 15 channels available in Sensitivity
Tune
• New Calibration editor screen
• File archive and extraction tool
• Self-diagnostics
G1834A A.01.00 A.02.02 Windows NT4 SP6a • Multi tune (for easier ORS
- A.02.01 / GP-IB operation)
Table 1: Agilent 7500 ICP-MS ChemStation upgrades available on-line for Windows XP, 2000 and NT operating systems.
7www.agilent.com/chem/icpms Agilent ICP-MS Journal January 2008 - Issue 33
New, Easier to AlignTorch for 7500 SeriesICP-MS Paul McMahon Technical Marketing Engineer, TokyoAnalytical Division, Agilent Technologies
Figure 1. New Standard Torch, 2.5 mm, 2 projections, HMI compatible, (Agilent productnumber: G3270-67002)
Agilent has modified the design ofthe standard quartz torch for the7500 Series ICP-MS for more precise,all round alignment.
Agilent’s standard torch and standalready allow precise alignment inthe x- and y-axis. However, theaddition of an extra projection thatfits to a hole in the new torch standprovides reproducible alignment inthe z-axis as well. The new standardtorch is also compatible with theHigh Matrix Introduction (HMI)accessory.
The new torch stand (Agilent productnumber: G3270-60501) is availableby contacting your Agilent representative. Note: the new torchcan be used without upgrading thetorch stand.
The new 2.5 mm internal diametertorch (Agilent product number:G3270-67002) is backward compatiblewith all Agilent 7500 Series modelsand replaces G1833-65423, which isno longer available.
To order the new torch, please visitthe on-line Agilent Store at:•www.agilent.com/chem/store•Click on “7500 Series Supplies”
under “ICP Mass Spectrometry”•Look for item G3270-67002 in
“Torch Supplies”or•Enter the torch product number,
G3270-67002, in the “Search Store” facility
User Testimonials: 7500 Series Carries Onfollowing Lab PowerLoss In separate incidents in labs in the US and UK, the 7500 Series has provedresilient to power fluctuations –helping users to remain productivewhen other instrumentation failed.
As Ernie Walton of TestAmerica inSavannah, USA explained: “We wererunning the Agilent 7500c whenthere was a brownout (reduction involtage) in the lab, the lights dimmedand some instruments and computersshutdown but the Agilent 7500c justkept on going!” Although brownoutsare uncommon in the lab, the 7500’srobustness enabled TestAmerica tocarry on their ICP-MS analysesuninterrupted.
Dr Teresa Jeffries, ICP-MS FacilityManager at the National HistoryMuseum, London, UK, was equallyimpressed with the 7500’s enduranceas she explains: “We had a power failure last night. I had a visitorhere running the instrument at thetime. The user was of course rathershocked as everything shut off aroundhim, and really worried that thismorning he would come in to findchaos. However I have to say I wasastonished this morning to find theAgilent 7500cs had got itself pumpeddown again. It fired up as normaland has required absolutely noretuning or anything”.
The 7500 Series’ efficient recoveryafter power loss is due to its designcriteria and build quality. AllAgilent ICP-MS are manufacturedin accordance with a strict qualityregulation program which includesenvironmental testing for shock,vibration, electrostatic dischargeand unusual power line conditions.In addition, an auto-recovery functionallows the 7500 to automaticallyreturn to stand-by mode (vacuumready) following an interruption inthe power supply – minimizingdowntime for users.
If you want to reduce the acousticnoise generated by the vacuumpump of your 7500 ICP-MS, Agilenthas a solution in the form of the“Quiet Cover II” (Figure 1).
Figure 1. Quiet Cover II installed on a 7500 ICP-MS
The new cover (product number:G3199B) is compatible with a rangeof BOC Edwards pumps includingthe E2M18 used with Agilent 7500ICP-MS.
The Quiet Cover offers:•Reduced pump noise: sound
absorbing cabinet with resistant foam insulation
•Easy movement with locking castors
•Easy access: no tools necessary toremove sectioned cover
•Easy to maintain: built in “Lift and Tilt” lever raises end of pumpto drain oil
•Stable temperature: two integrated fans maintain temperature inside cover
For More Information visit:www.agilent.com/chem/quietcoverII
This information is subject to change without notice
Karen Morton for Agilent Technologiese-mail: [email protected] ICP-MS Journal Editor
4500 Series Reaches EOS The Agilent 4500 Series ICP-MS has reached its End of Support (EOS). For more information on transitioning to the 7500 Series, contact yourAgilent support sales representative or visit: www.agilent.com/chem/icpms
Trade Shows and ConferencesPittcon 2008March 1–7, 2008, New Orleans, LA, USA www.pittcon.org
Agilent ICP-MS PublicationsTo view and download these latest publications, go towww.agilent.com/chem/icpms and look under "Library Information"
• Application: Direct Elemental Analysis of Biodiesel by 7500ce ICP-MS with ORS, 5989-7649EN
• Success Story: Sanofi-aventis, A high throughput assay for oxaliplatin inclinical samples, 5989-7077EN
Front page photo:Agilent’s Dr. Junichi Takahashi (left), senior applications specialist in theSemiconductor Marketing Group based in Tokyo, Japan, receiving anaward from the Japan Society for Analytical Chemistry in recognition ofhis 30 year contribution to the development of trace elemental analysis byatomic spectroscopy.
The 15th Winter Plasma Conferencewas held on Jan 7-12th in Temecula,California, USA and was well atten-ded by plasma spectrochemists fromaround the world. This year’s confe-rence featured especially strong ses-sions on metallomics and proteo-mics confirming that there is a greatdeal of research activity in theseareas.
As ever Agilent held an ICP-MS UserMeeting which was very well atten-ded with over 180 users joining us inthe conference hotel on Tuesdayevening. This year, our regularmaster of ceremonies, Chris Scanlonbrought us something different –Elemental Bingo! A great time washad by all.
Here’s looking forward to the nextWinter Conferences in Tsukuba,Japan, Nov 16-21, 2008 and Graz,Austria, Feb 17-20, 2009.
Winter Plasma Conference 2008 Don Potter Worldwide ICP-MS Marketing Manager, Tokyo Analytical Division, Agilent Technologies
Elemental Bingo master, Chris Scanlon, in action at Agilent’s ICP-MS user meeting
New Agilent ICP-MS Users
A very warm welcome to all companiesand institutions that have recentlyadded an Agilent ICP-MS to theiranalytical facilities. Remember tojoin the Agilent web-based ICP-MSUser Forum – the place where youcan exchange information relatingto your new ICP-MS. You will alsofind a host of resources in theForum designed to help you get themost from your 7500.
To access the Forum, you will simplyneed to log-in to the Agilent website, or register if you haven't doneso previously, and enter yourinstrument's serial number on yourfirst visit only. Look for the link tothe ICP-MS User Forum from:www.agilent.com/chem/icpms
