Date post: | 16-Dec-2015 |
Category: |
Documents |
Upload: | bailee-hartley |
View: | 226 times |
Download: | 2 times |
XRFX-ray Fluorescence
Spectrometry
Tom Murphy
XRFX-ray Fluorescence
Spectrometry
Tom Murphy
Qualitative ScreeningQualitative Screening
oror
Quantitative AnalysisQuantitative Analysis
Major Users of XRFMajor Users of XRF
GeoprospectingGeoprospecting
Alloy identification for safety and recyclingAlloy identification for safety and recycling
Remediation of lead in paint, metals in soilRemediation of lead in paint, metals in soil
Waste processing such as oil industryWaste processing such as oil industry
Forensics for legal analysisForensics for legal analysis
Consumer product analysis Consumer product analysis
Art and ArcheologyArt and Archeology
Industrial hygieneIndustrial hygiene
More powerful units More powerful units have radioactive have radioactive source, better source, better detection levels, detection levels, fewer interferences, fewer interferences, but are not usually but are not usually portable, and if portable, and if portable require portable require licensinglicensing
Hand-held XRF – Thermo Fisher Hand-held XRF – Thermo Fisher LoanLoan
-analysis in ~1 minute-analysis in ~1 minute -no extraction or other -no extraction or other
preparation of samplepreparation of sample -detects ppm concentrations of -detects ppm concentrations of
many metalsmany metals -non destructive-non destructive -no cross contamination or -no cross contamination or
fouling of sensorfouling of sensor
Sample Preparation/CalibrationSample Preparation/Calibration The sample matrix can be importantThe sample matrix can be important
The best cases really suitable for XRF analysis is The best cases really suitable for XRF analysis is the ‘atomic mixing level’ that is found in:the ‘atomic mixing level’ that is found in:
-All liquids (homogenous, one physical phase!)-All liquids (homogenous, one physical phase!) -Glass-Glass -Large crystals (used for “finger printing” gem -Large crystals (used for “finger printing” gem
origins)origins) -Most alloys-Most alloys
Mixing varies from impossible to Mixing varies from impossible to easyeasy-results vary from qualitative to -results vary from qualitative to quantitativequantitative
Oil in mineral Oil in mineral precipitant precipitant “impossible” to “impossible” to mixmix
Toxic skin Toxic skin cream can mix cream can mix but will but will separate, “Cao separate, “Cao Cap”Cap”
This fish needs This fish needs a better a better grinder but can grinder but can shoot shoot replicatesreplicates
InterferencesInterferences
A few elements interfere, arsenic and lead can A few elements interfere, arsenic and lead can effect each other, especially in low energy XRFseffect each other, especially in low energy XRFs-in samples with high lead, low arsenic results will -in samples with high lead, low arsenic results will be unreliable be unreliable
The Matrix can be an issue. If there is more than The Matrix can be an issue. If there is more than 10% water in a sample, it can either enhance or 10% water in a sample, it can either enhance or reduce the signal. Drying of the sample is reduce the signal. Drying of the sample is required.required.
Geoprospecting – Pathfinder analysisGeoprospecting – Pathfinder analysis-can’t see low concentrations of gold with XRF -can’t see low concentrations of gold with XRF but can find co-occurring elements like platinumbut can find co-occurring elements like platinum
JewelryJewelry-XRF quickly detects Pb, Hg, Cd -XRF quickly detects Pb, Hg, Cd etc.etc.-no sample preparation-no sample preparation
Found clasps with Found clasps with >40% Pb>40% Pb-ingestion has killed -ingestion has killed child in USAchild in USA-chronic toxicity -chronic toxicity more commonmore common
Lead Amulets/Curse Tablets -oral very dangerous, dermal less dangerous but not well documented, no sample preparation needed for XRF
Lead Amulets/Curse Tablets -oral very dangerous, dermal less dangerous but not well documented, no sample preparation needed for XRF
- Khmer Beads 45% - Khmer Beads 45% leadlead
ThaiThai CharmCharmRoman Roman Curse Curse TabletTablet
Other Consumer Other Consumer Products?Products?-cooking ware – old ceramics, poorly -cooking ware – old ceramics, poorly made metal waremade metal ware-Degree of extractability is important-Degree of extractability is important-Cooking acidic foods is more -Cooking acidic foods is more dangerousdangerous
-1/3-1/3rdrd of toys here are toxic by EU of toys here are toxic by EU regulationsregulations-a few times toys were removed from -a few times toys were removed from US StoresUS Stores
http://www.environment.gov.au/atmosphere/airquality/publications/ceramics.html-Lead glazes are most commonly used on earthenware, and on older bone china and porcelain.-If they are not properly prepared and fired, lead may leach (i.e. move from the glaze) into food stored in or on the ceramic ware.-Acidic foods will accelerate any leaching.-Ceramic ware with a corroded glaze is extremely dangerous.-Reheating coffee in an old mug in the microwave is a particularly risky thing to do.
Porcelain
Cooking Ware/ArcheologyCooking Ware/Archeology
Fall of Roman Empire – one theory of several
The presence of lead in the drinking water leached in from the water pipes, glazes on containers that came in contact with food and beverages, and food preparation techniques could have contributed to heavy metal poisoning.
It was also absorbed through the pores, since it was used in cosmetics.
Roman use of lead - as cosmetics, pipes, jewelry, - as cosmetics, pipes, jewelry, curse tablets, utensils and cooking pots, and, of curse tablets, utensils and cooking pots, and, of course course sapa and defrutum (wine boiled down in (wine boiled down in lead pots)lead pots)
Lead levels in bones from the Imperial Roman period had up to 30 mg/kg, which is three times higher than the level the WHO considers "very severe lead poisoning."
PaintPaint-lead in paint only found now in -lead in paint only found now in developing countriesdeveloping countries-essential and easy to mix can of paint-essential and easy to mix can of paint-to process dried paint on a surface -to process dried paint on a surface requires a more powerful XRF and requires a more powerful XRF and results are qualitativeresults are qualitative
Thai Paint with up to 5% Thai Paint with up to 5% leadlead
Problem?Problem?Small children put pieces Small children put pieces of old paint in their of old paint in their mouthsmouths..-price of renovation in -price of renovation in USAUSA
Previous Thermo CollaborationPrevious Thermo Collaboration -processed 675 skin -processed 675 skin
creamscreams -33% of samples -33% of samples
from beauty shops from beauty shops exceeded guidelines exceeded guidelines
-up to 3%Hg -up to 3%Hg
Murphy, T.P., S. Lim, S.P. Huong, K. Irvine, S. Bayen, B, Kelly and K. Wilson. 2012. Application of Handheld X-Ray Fluorescence Analyzers to Identify Mercury in Skin Whitening Creams in Cambodia. J Health Pollut. 3:21-31
The spiked recovery used The spiked recovery used DMSODMSO for good mixing. for good mixing.Quantitative for <2000 ppm HgQuantitative for <2000 ppm HgA reduced response for >2000 Hg but still useful.A reduced response for >2000 Hg but still useful.No certified reference materials available for this No certified reference materials available for this analysisanalysis. .
Skin Cream Validation -Skin Cream Validation -11
XRF Validation -2XRF Validation -2
Comparison of XRF and ICP-OES is fineComparison of XRF and ICP-OES is fineAgain, there were no certified reference materials for Again, there were no certified reference materials for skin creams.skin creams.There are several standard reference materials for There are several standard reference materials for fish etc. fish etc. When possible use certified reference materials.When possible use certified reference materials.
Product Name Apparent Source Total MercuryEucerin USA 23200Hua Tha Li China 19256Chang Chun China 18458Enjoy USA 13800Rojzy Jiali Vietnam 12528Yimei Yellow China 12014Guoyao China 11500Diamond Unknown 6147Hua Hin China 5454Qian Mei China 5110FC Cambodia 4979Malis Thailand 3552Lulanjena China 2990Oreal2 Unknown 2852Maly Thailand 1938Japanese Japan 1652SS-II Unknown 1410Britney Cambodia 1223Mlis Thailand 996
Mercury in Skin Creams in Phnom Mercury in Skin Creams in Phnom Penh ppmPenh ppm
Other cosmetics warrant analysis, Other cosmetics warrant analysis, managementmanagement-a blush containing 878 ppm of cadmium -a blush containing 878 ppm of cadmium -users all reacted to it and passed to their -users all reacted to it and passed to their friendsfriends
EnvironmentEnvironmentCanadaCanada
EnvironnementEnvironnementCanadaCanada
Waste disposal Waste disposal - PVC pipe has 7000 to 9000 ppm of lead- PVC pipe has 7000 to 9000 ppm of lead- Should not be burned without emission - Should not be burned without emission treatmenttreatment- Similar concerns about future oil and - Similar concerns about future oil and gas industry wastesgas industry wastes
Other Hydrocarbons, ThermalOther Hydrocarbons, ThermalThermal power plants to be fired by Khmer Thermal power plants to be fired by Khmer coalcoal-Sulphur, Arsenic, mercury content?-Sulphur, Arsenic, mercury content?-risk of acidification in soft water -risk of acidification in soft water environmentenvironment
-Mercury in natural gas?-Mercury in natural gas?
Khmer CoalKhmer Coal
Units ppm, Khmer coal formed in freshwater, low Units ppm, Khmer coal formed in freshwater, low SulphurSulphur
Source Mean Sulphur
Arsenic Mercury
Preah Vihear, Cam.
8419 30 ND
Springfield USA1
32000 9.8 0.12
Appalachian1
USA280002 351 0.211
Wyoming USA3 6300 2.6 0.13
Concerns with CoalConcerns with CoalThe Cardamom mountains are granitic and thus they The Cardamom mountains are granitic and thus they have little buffering capacity.have little buffering capacity.Burning coal produces sulphuric acid.Burning coal produces sulphuric acid.Without emission treatment acid rain from burning Without emission treatment acid rain from burning coal in such an environment could kill most plants and coal in such an environment could kill most plants and water lifewater lifeAt least the sulphur content is not highAt least the sulphur content is not high