Sector Field ICP-MS Research Articles

High-Resolution Inductively Coupled Plasma Optical Emission Spectrometry for (234)U/(238)Pu Age Dating of Plutonium Materials and Comparison to Sector Field Inductively Coupled Plasma Mass Spectrometry.

Employing a commercial high-resolution inductively coupled plasma optical emission spectrometry (HR-ICP-OES) instrument, an innovative analytical procedure for the accurate determination of the production age of various Pu materials (Pu powder, cardiac pacemaker battery, (242)Cm heat source, etc.) was developed and validated. This undertaking was based on the fact that the α decay of (238)Pu present in the investigated samples produced (234)U and both mother and daughter could be identified unequivocally using HR-ICP-OES. Benefiting from the high spectral resolution of the instrument (<5 pm) and the isotope shift of the emission lines of both nuclides, (234)U and (238)Pu were selectively and directly determined in the dissolved samples, i.e., without a chemical separation of the two analytes from each other. Exact emission wavelengths as well as emission spectra of (234)U centered around λ = 411.590 nm and λ = 424.408 nm are reported here for the first time. Emission spectra of the isotopic standard reference material IRMM-199, comprising about one-third each of (233)U, (235)U, and (238)U, confirmed the presence of (234)U in the investigated samples. For the assessment of the (234)U/(238)Pu amount ratio, the emission signals of (234)U and (238)Pu were quantified at λ = 424.408 nm and λ = 402.148 nm, respectively. The age of the investigated samples (range: 26.7-44.4 years) was subsequently calculated using the (234)U/(238)Pu chronometer. HR-ICP-OES results were crossed-validated through sector field inductively coupled plasma mass spectrometry (SF-ICPMS) analysis of the (234)U/(238)Pu amount ratio of all samples applying isotope dilution combined with chromatographic separation of U and Pu. Available information on the assumed ages of the analyzed samples was consistent with the ages obtained via the HR-ICP-OES approach. Being based on a different physical detection principle, HR-ICP-OES provides an alternative strategy to the well-established mass spectrometric approach and thus effectively adds to the quality assurance of (234)U/(238)Pu age dates.

Resolution of rare earth element interferences in fossil energy by-product samples using sector-field ICP-MS

The supply and price of rare earth elements (REEs) have become a concern to many countries in the world, which has led to renewed interest in exploration and recovery of REEs from secondary or waste sources. Potential high REE waste sources that are of particular interest are coal mining, preparation, combustion, and other fossil energy by-products, including those from natural gas production. In this work, we have examined a set of five solid samples from the treatment of produced and flowback water containing elevated concentrations of barium. In order to confirm the correct concentrations of Eu, we studied these materials using sector field inductively coupled plasma mass spectrometry (SF-ICP-MS), which is capable of resolving species of nearly identical masses, including Eu and BaO. While the use of quadrupole inductively coupled plasma mass spectrometry (Q-ICP-MS) for the REE analysis of most geological sample matrices should pose no problem, the presence of large amounts of Ba, as encountered in water treatment solids from natural gas produced and flowback samples may require SF-ICP-MS for accurate determination of all REEs.

Method for Ultratrace Level (241)Am Determination in Large Soil Samples by Sector Field-Inductively Coupled Plasma Mass Spectrometry: With Emphasis on the Removal of Spectral Interferences and Matrix Effect.

A new method using sector field-inductively coupled plasma mass spectrometry (SF-ICPMS) was developed for the determination of (241)Am in large soil samples to provide realistic soil-plant transfer parameter data for dose assessment of nuclear waste disposal plans. We investigated four subjects: extraction behaviors of interfering elements (Bi, Tl, Hg, Pb, Hf, and Pt) on DGA resin (normal type, abbreviated as DGA-N); soil matrix element removal (Mg, Fe, Al, K, Na) using Fe(OH)3, CaF2, and CaC2O4 coprecipitations; Am and rare earth elements (REEs) separation on DGA-N and TEVA resins; and optimization of SF-ICPMS (equipped with a high efficiency nebulizer (HEN)) for Am determination. Our method utilized concentrated HNO3 to leach Am from 2 to 20 g soil samples. The CaC2O4 coprecipitation was used to remove major metals in soil and followed by Am/interfering elements separation using the proposed UTEVA + DGA-N procedure. After a further separation of REEs on TEVA resin, (241)Am was determined by HEN-SF-ICPMS. This method eliminated the matrix effect in ICPMS (241)Am measurement for large soil samples. The high decontamination factors (DFs) of interfering elements enable their thorough removal, and in particular, the DF of Pu (7 × 10(5)) was the highest ever reported in (241)Am studies; thus, this method is capable of analyzing (241)Pu-contaminated Fukushima Daiichi Nuclear Power Plant (FDNPP) sourced soil samples. A low detection limit of 0.012 mBq g(-1) for (241)Am was achieved. The chemical recovery of Am (76-82%) was stable for soil samples. This method can be employed for the low level (241)Am determination in large size soil samples that are contaminated with (241)Pu.

Depleted and enriched uranium exposure quantified in former factory workers and local residents of NL Industries, Colonie, NY USA

BackgroundBetween 1958 and 1982, NL Industries manufactured components of enriched (EU) and depleted uranium (DU) at a factory in Colonie NY, USA. More than 5 metric tons of DU was deposited as microscopic DU oxide particles on the plant site and surrounding residential community. A prior study involving a small number of individuals (n=23) indicated some residents were exposed to DU and former workers to both DU and EU, most probably through inhalation of aerosol particles. ObjectivesOur aim was to measure total uranium [U] and the uranium isotope ratios: 234U/238U; 235U/238U; and 236U/238U, in the urine of a cohort of former workers and nearby residents of the NLI factory, to characterize individual exposure to natural uranium (NU), DU, and EU more than 3 decades after production ceased. MethodsWe conducted a biomonitoring study in a larger cohort of 32 former workers and 99 residents, who may have been exposed during its period of operation, by measuring Total U, NU, DU, and EU in urine using Sector Field Inductively Coupled Plasma - Mass Spectrometry (SF-ICP-MS). ResultsAmong workers, 84% were exposed to DU, 9% to EU and DU, and 6% to natural uranium (NU) only. For those exposed to DU, urinary isotopic and [U] compositions result from binary mixing of NU and the DU plant feedstock. Among residents, 8% show evidence of DU exposure, whereas none shows evidence of EU exposure. For residents, the [U] geometric mean is significantly below the value reported for NHANES. There is no significant difference in [U] between exposed and unexposed residents, suggesting that [U] alone is not a reliable indicator of exposure to DU in this group. ConclusionsNinety four percent of workers tested showed evidence of exposure to DU, EU or both, and were still excreting DU and EU decades after leaving the workforce. The study demonstrates the advantage of measuring multiple isotopic ratios (e.g., 236U/238U and 235U/238U) over a single ratio (235U/238U) in determining sources of uranium exposure.

Evaluation of whole blood zinc and copper levels in children with autism spectrum disorder.

Zinc (Zn) and copper (Cu) are important trace elements for cognitive development and normal neurological functioning. Autism spectrum disorder (ASD) is a common neurological disorder, which has previously been associated with the levels of some trace elements in the blood. However, clinical data regarding the potential implication of Zn and Cu in patients with ASD are still insufficient. Therefore, the aim of the present study was to investigate the whole blood levels of Zn and Cu in a cohort of 28 children with ASD and 28 age- and gender-matched healthy controls. Whole blood Zn and Cu levels were assessed using inductively-coupled plasma-sector field mass spectrometry. Both in the control and in the ASD group, the values of whole blood Cu and Zn were characterized by a Gaussian distribution. The results indicate that the ASD children were characterized by ~10% (p=0.005) and ~12% (p=0.015) lower levels of whole blood Zn and Zn/Cu ratio, respectively, in comparison to controls. No significant difference in whole blood Cu was observed. However, Cu/Zn ratio was ~15% (p=0.008) higher in ASD children than that in the control ones. The results of the present study may be indicative of Zn deficiency in ASD children. Taking into account Zn-mediated up-regulation of metallothionein (MT) gene expression, these findings suggest a possible alteration in the functioning of the neuroprotective MT system. However, further investigations are required to test this hypothesis.

Comparison of analytical methods: ICP-QMS, ICP-SFMS and FF-ET-AAS for the determination of V, Mn, Ni, Cu, As, Sr, Mo, Cd and Pb in ground natural waters

ABSTRACTThree analytical methods, namely, inductively coupled plasma sector field mass spectrometry (ICP-SFMS); inductively coupled plasma quadrupole mass spectrometry (ICP-QMS) and filter-furnace electrothermal atomic-absorption spectroscopy (FF-ET-AAS) for the determination of V, Mn, Ni, Cu, As, Sr, Mo, Cd and Pb in ground natural water samples were compared and evaluated for their capacity to provide reliable and precise results. Two certified reference materials (SLEW-3 Estuarine Water; SLRS-4 River Water) were analysed to prove that accurate results could be obtained by using all the listed methods with properly optimised parameters. The limit of detection (LOD) for V, Mn, Ni, Cu, As, Sr, Mo, Cd and Pb provided by the ICP-MS methods ranged from 0.001 to 0.05 µg L−1. Such LOD proved sufficient for the reliable determination of the listed elements in ground natural waters. However, the LOD of the FF-ET-AAS was approximately two orders of magnitude higher than that of ICP-MS, which made it impossible to quantify V, Mn, Ni, Mo and Pb. The effects of the usage of the collision cell mode in ICP-QMS and of the desolvation system Apex for ICP-SFMS to eliminate oxide ions levels were investigated. For all three analytical methods, the influence of the matrix effect on the results of the determination of the investigated elements using matrix model solution, external calibration and standard addition methods was evaluated. A comparison using a paired Student’s t-test between the results obtained by both ICP-MS methods for V, Mn, Ni, Cu, As, Sr, Mo, Cd and Pb concentrations in ground natural waters showed that there was no significant difference on a 95% confidence level. The precision of the results for ICP-SFMS, ICP-QMS and FF-ET-AAS varied between ~0.5 and 11; 2.5 and 12.5; 3 and 13.5%, respectively. Moreover, ICP-SFMS equipped with the desolvation system APEX proved a better choice for As, Cu and Mn analysis due to its better LOD (0.008, 0.03 and 0.02 µg L−1, respectively) and precision (Sr ≤ 5.0; 7.5; 9.0%, respectively) compared to ICP-QMS and FF-ET-AAS.

Serum Copper Status in School-Age Children and Pregnant Women in China Nutrition and Health Survey 2010-2012.

Serum copper is an insensitive but reliable biomarker reflecting the change of copper nutritional status in both depleted and replete populations. The current study aimed to establish the reference values of serum copper in school-age children and pregnant women in China and to explore the adequate range of serum copper for both these two categories of people. A multistage, stratified, random sampling combined with probability proportionate to regional size sampling method was employed. A total of 4019 subjects (2736 school-age children and 1283 pregnant women) were selected from China Nutrition and Health Survey 2010-2012 (CNHS 2010-2012). The concentration of serum copper was determined by sector field inductively coupled plasma mass spectrometry (SF-ICP-MS). The adequate range of serum copper was determined by the logistic sigmoid saturation curve of the median derivatives. The median concentration of serum copper was 1140.9μg/L with a range of 746.7-1677.6μg/L for school-age children and 1933.4μg/L with a range of 947.4-3391.4μg/L for pregnant women. The adequate range of serum copper was 905.7-1440.7μg/L for school-age children and 1308.8-2537.8μg/L for pregnant women. These parameters represent an essential prerequisite for the assessment of copper nutritional status, as well as nutrition interventions.

Acquisition of fast transient signals in ICP-MS with enhanced time resolution

Improving time resolution in sector-field ICP-MS through use of a plug-in data acquisition board.

Mass spectrometric searches for superheavy elements in terrestrial matter

Recent searches for traces of long-lived superheavy elements (SHEs) in terrestrial materials by mass spectrometric means are reviewed. Positive evidence for long-lived neutron-deficient Th isotopes in Th and Rg isotopes in Au, and a possible A=292, Z∼122 nuclide in Th was reported from experiments with Inductively Coupled Plasma Sector Field Mass Spectrometry (ICP-SF-MS). These findings were not confirmed with Accelerator Mass Spectrometry (AMS), with abundance limits lower by several orders of magnitude. In addition, the extensive AMS searches for 42 SHE nuclides (A=288–310) around the much discussed “island of stability” (Z=114, N=184) in natural Pt, Au, Pb, Bi materials are reviewed. Due to the flatness of the mass distribution and the relatively large bandwidth of the mass acceptance in AMS searches, an effectively much larger number of SHE nuclides was scanned in the respective materials. No positive evidence for the existence of long-lived SHEs (t1/2>108 yr) with abundance limits of 10−12 to 10−16 was found.

One-million year Rare Earth Element stratigraphies along an Antarctic marine sediment core

An integrated system, based on Inductively Coupled Plasma-Sector Field Mass Spectrometry (ICP-SFMS) and Inductively Coupled Plasma-Atomic Emission Spectrophotometry (ICP-AES) techniques, was optimised for the geochemical characterisation of soils and marine sediments. Sample mineralization was carried out with HF, HNO3 and HClO4. Operative blanks were at least two orders of magnitude lower than the lowest concentration measured in real samples. For ICP-SFMS, the detection power of the method in high resolution mode was sufficient for an accurate quantification of metals, yet avoiding REEs' (Rare Earth Elements) isobaric interferences. Once tested the accuracy on six certified materials, the methods were applied to the analysis of 39 major and trace metals on the top 90m of sediments from the ANDRILL AND-1B core, covering the last million years.Stratigraphies of REEs and of normalised markers from this core clearly highlight a discontinuity at about 660,000years before present. This pattern is well shown by the results of a PMF (Positive Matrix Factorization) statistical analysis, revealing two different sources for the sedimentary material, whose relative contribution changed around that time. Such a result is consistent with previous studies and confirms the net change in the provenance of glacial fluxes in the McMurdo region (Ross Ice Shelf, Antarctica) in the last million years.

Assessing the role of chemical components in cellular responses to atmospheric particle matter (PM) through chemical fractionation of PM extracts.

In order to further our understanding of the influence of chemical components and ultimately specific sources of atmospheric particulate matter (PM) on pro-inflammatory and other adverse cellular responses, we promulgate and apply a suite of chemical fractionation tools to aqueous aerosol extracts of PM samples for analysis in toxicity assays. We illustrate the approach with a study that used water extracts of quasi-ultrafine PM (PM0.25) collected in the Los Angeles Basin. Filtered PM extracts were fractionated using Chelex, a weak anion exchanger diethylaminoethyl (DEAE), a strong anion exchanger (SAX), and a hydrophobic C18 resin, as well as by desferrioxamine (DFO) complexation that binds iron. The fractionated extracts were then analyzed using high-resolution sector field inductively coupled plasma mass spectrometry (SF-ICPMS) to determine elemental composition. Cellular responses to the fractionated extracts were probed in an in vitro rat alveolar macrophages model with measurement of reactive oxygen species (ROS) production and the cytokine tumor necrosis factor-α (TNF-α). The DFO treatment that chelates iron was very effective at reducing the cellular ROS activity but had only a small impact on the TNF-α production. In contrast, the hydrophobic C18 resin treatment had a small impact on the cellular ROS activity but significantly reduced the TNF-α production. The use of statistical methods to integrate the results across all treatments led to the conclusion that sufficient iron must be present to participate in the chemistry needed for ROS activity, but the amount of ROS activity is not proportional to the iron solution concentration. ROS activity was found to be most related to cationic mono- and divalent metals (i.e., Mn and Ni) and oxyanions (i.e., Mo and V). Although the TNF-α production was not significantly affected by the chelexation of iron, it was greatly impacted by the removal of organics with the C18 resin and all other metal removal methods, suggesting that iron is not a critical pathway leading to TNF-α production, but a wide range of soluble metals and organic compounds in particulate matter play a role. Although the results are specific to the Los Angeles Basin, where the samples used in the study were collected, the method employed in the study can be widely employed to study the role of components of particulate matter in in vitro or in vivo assays.

Pulmonary clearance kinetics and extrapulmonary translocation of seven titanium dioxide nano- and submicron materials following intratracheal administration in rats

We evaluated and compared the pulmonary clearance kinetics and extrapulmonary translocations of seven titanium dioxide (TiO2) nano- and submicron particles with different characteristics, including size, shape and surface coating. Varying doses of TiO2 nano- and submicron particles dispersed in 0.2% disodium phosphate solution were intratracheally administered to male F344 rats. The rats were euthanized under anesthesia for 3, 28 and 91 days after administration. Ti levels in pulmonary and various extrapulmonary organs were determined using inductively coupled plasma-sector field mass spectrometry (ICP-SFMS). The lungs, including bronchoalveolar lavage fluid (BALF), contained 55–89% of the administered TiO2 dose at 3 days after administration. The pulmonary clearance rate constants, estimated using a one-compartment model, were higher after administration of 0.375–2.0 mg/kg body weight (bw) (0.016–0.020/day) than after administration of 3.0–6.0 mg/kg bw (0.0073–0.013/day) for six uncoated TiO2. In contrast, the clearance rate constant was 0.011, 0.0046 and 0.00018/day following administration of 0.67, 2.0 and 6.0 mg/kg bw TiO2 nanoparticle with Al(OH)3 coating, respectively. Translocation of TiO2 from the lungs to the thoracic lymph nodes increased in a time- and dose-dependent manner. Furthermore, the translocation of TiO2 from the lungs to the thoracic lymph nodes after 91 days was higher when Al(OH)3 coated TiO2 was administered (0.93–6.4%), as compared to uncoated TiO2 (0.016–1.8%). Slight liver translocation was observed (<0.11%), although there was no clear trend related to dose or elapsed time. No significant translocation was observed in other organs including the kidney, spleen and brain.

Development, validation, and application of an ultra-performance liquid chromatography–sector field inductively coupled plasma mass spectrometry method for simultaneous determination of six organotin compounds in human serum

Organotin compounds (OTCs) are heavily employed by industry for a wide variety of applications, including the production of plastics and as biocides. Reports of environmental prevalence, differential toxicity between OTCs, and poorly characterized human exposure have fueled the demand for sensitive, selective speciation methods. The objective of this investigation was to develop and validate a rapid, sensitive, and selective analytical method for the simultaneous determination of a suite of organotin compounds, including butyl (mono-, di-, and tri-substituted) and phenyl (mono-, di-, and tri-substituted) species in human serum. The analytical method utilized ultra-performance liquid chromatography (UPLC) coupled with sector field inductively coupled plasma mass spectrometry (SF-ICP-MS). The small (sub-2µm) particle size of the UPLC column stationary phase and the sensitivity of the SF-ICP-MS enabled separation and sensitive determination of the analyte suite with a runtime of approximately 3min. Validation activities included demonstration of method linearity over the concentration range of approximately 0.250–13.661ngmL−1, depending on the species; intraday precision of less than 21%, interday precision of less than 18%, intraday accuracy of −5.3% to 19%, and interday accuracy of −14% to 15% for all species; specificity, and matrix impact. In addition, sensitivity, and analyte stability under different storage scenarios were evaluated. Analyte stability was found to be limited for most species in freezer, refrigerator, and freeze–thaw conditions. The validated method was then applied for the determination of the OTCs in human serum samples from women participating in the Snart-Foraeldre/MiljØ (Soon-Parents/Environment) Study. The concentration of each OTC ranged from below the experimental limit of quantitation to 10.929ngtin (Sn)mL−1 serum. Speciation values were confirmed by a total Sn analysis.

Challenges in the quality assurance of elemental and isotopic analyses in the nuclear domain benefitting from high resolution ICP-OES and sector field ICP-MS.

Accurate analytical data reinforces fundamentally the meaningfulness of nuclear fuel performance assessments and nuclear waste characterization. Regularly lacking matrix-matched certified reference materials, quality assurance of elemental and isotopic analysis of nuclear materials remains a challenging endeavour. In this context, this review highlights various dedicated experimental approaches envisaged at the European Commission—Joint Research Centre—Institute for Transuranium Elements to overcome this limitation, mainly focussing on the use of high resolution-inductively coupled plasma-optical emission spectrometry (HR-ICP-OES) and sector field-inductively coupled plasma-mass spectrometry (SF-ICP-MS). However, also α- and γ-spectrometry are included here to help characterise extensively the investigated actinide solutions for their actual concentration, potential impurities and isotopic purity.

Determination of Ga, Ge, Mo, Ag, Cd, In, Sn, Sb, W, Tl and Bi in USGS Whole‐Rock Reference Materials by Standard Addition ICP‐MS

A procedure for determining a wide range of chalcophile and siderophile elements in typical crustal rocks using standard addition and ICP‐SFMS (inductively coupled plasma sector field mass spectrometry) is presented. New results for Ga, Ge, Mo, Ag, Cd, In, Sn, Sb, W, Tl and Bi abundances in USGS whole‐rock reference materials AGV‐2, BHVO‐1, BIR‐1, G‐2, GSP‐1 and W‐2 are reported using this analytical procedure. Intermediate precision of means based on multiple dissolved aliquots of each USGS reference material was 10% RSD or better for Ga, Ge, In and Sn in all, and similarly good for Ag, Cd, Sb, Tl and Bi in most reference materials. Poorer intermediate precision of Mo and W measurements in several reference materials is probably due to higher analytical blanks on these elements and powder heterogeneity due to a sulfide‐related nugget effect in the specific case of Mo in GSP‐1. Results for all elements fell within the range of available published data with the exception of Ag, which yielded systematically higher concentrations than found in the literature for five of the six reference materials, likely reflecting interference from unresolved polyatomic species.

ICP-OES: Why spectral lines are true peaks and how this can fool the user.

ICP-OES: Why spectral lines are true peaks and how this can fool the user.

Evaluation of a new sector-field ICP-MS with Jet Interface for ultra-trace determination of Pu isotopes: from femtogram to attogram levels

Evaluation of a new sector-field ICP-MS with Jet Interface for ultra-trace determination of Pu isotopes: from femtogram to attogram levels

The benefits and limitations of reaction cell and sector field inductively coupled plasma mass spectrometry in the detection and quantification of phosphopeptides.

The phosphorylation of proteins is one of the most important post-translational modifications in nature. Knowledge of the quantity or degree of protein phosphorylation in biological samples is extremely important. A combination of liquid chromatography (LC) and inductively coupled plasma mass spectrometry (ICP-MS) allows the absolute and relative quantification of the phosphorus signal. A comparison between dynamic reaction cell quadrupole ICP-MS (DRC-Q-ICP-MS) and high-resolution sector field ICP-MS (SF-ICP-MS) in detecting signals of phosphorus-containing species using identical capillary LC (reversed-phase technology) and nebulizer settings was performed. A method to diminish the reversed-phase gradient-related signal instability in phosphorus detection with LC/ICP-MS applications was developed. Bis(4-nitrophenyl)phosphate (BNPP) was used as a standard to compare signal-to-noise ratios and limits of detection (LODs) between the two instrumental setups. The LOD reaches a value of 0.8 µg L(-1) when applying the DRC technology in Q-ICP-MS and an LOD of 0.09 µg L(-1) was found with the SF-ICP-MS setup. This BNPP standard was further used to compare the absolute quantification possibilities of phosphopeptides in these two setups. This one-to-one comparison of two interference-reducing ICP-MS instruments demonstrates that absolute quantification of individual LC-separated phosphopeptides is possible. However, based on the LOD values, SF-ICP-MS has a higher sensitivity in detecting phosphorus signals and thus is preferred in phosphopeptide analysis.

A feasibility study of the use of saliva as an alternative to leukocytes as a source of DNA for the study of Pt-DNA adducts in cancer patients receiving platinum-based chemotherapy.

This note presents a comparison of the use of saliva versus leukocytes for the determination of Pt-DNA adducts obtained from patients undergoing platinum-based chemotherapy. Samples of both blood and saliva were taken pre- and post-treatment and were analysed via sector-field inductively coupled plasma mass spectrometry (SF-ICP-MS) to determine the level of Pt-DNA adducts formed. As expected, significant inter-patient variability was seen; however, a lack of correlation between the levels of adducts observed in saliva and blood samples was also observed (Pearson correlation coefficient r = -0.2598). A high yield of DNA was obtained from saliva samples, but significant difficulties were experienced in obtaining patient adherence to the saliva sampling procedure. In both leukocyte and saliva samples, not only was Pt from previous chemotherapy cycles detected, but the rapid appearance of Pt in the DNA was noted in both sample types 1h after treatment.

Elemental fingerprinting of gypsum drywall using sector field ICP-MS and multivariate statistics

Outgassing of volatile sulphur compounds from gypsum drywall from some sources has resulted in odours, corrosion of wiring and metals and health problems for homeowners. Infrared spectroscopy has been the primary analytical tool to identify ‘problematic’ drywall. In this paper, we demonstrate that elemental fingerprinting using inductively coupled plasma mass spectrometry and multivariate statistics is an effective alternative. The approach also showed potential in determining the geographic source of gypsum. Nineteen elements (Al, Ba, Ca, Cd, Co, Cr, Cs, Cu, Fe, Mg, Mn, Ni, Pb, Rb, Sr, Tl, U, V and Zn) were measured in 20 samples of drywall, half of which were classified as positive for contamination by Fourier Transform Infrared Spectroscopy. Gypsum from three different mines and a flue gas desulphurisation plant were also analysed. Principal component analysis and multivariate analysis of variance of the elemental data showed significant differences between the problematic and non-problematic drywall and between sources of gypsum. Strontium averaged 1800 ± 500 µg/g in problematic drywall compared to 400 ± 100 µg/g in non-problematic drywall (p < 0.0001).