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Patrick J. Parsons - One of the best experts on this subject based on the ideXlab platform.

  • A critical review of the analysis of dried blood spots for characterizing human exposure to Inorganic targets using methods based on analytical atomic Spectrometry
    Journal of Analytical Atomic Spectrometry, 2020
    Co-Authors: Patrick J. Parsons, Aubrey L. Galusha, Yuxia Cui, Elaine M. Faustman, Jill C. Falman, John D. Meeker, Kurunthachalam Kannan
    Abstract:

    Dried blood spots (DBS) are well established in clinical laboratory medicine and are used to screen newborn babies for a large number of metabolomic disorders. More than 50 years ago, early attempts to analyze DBS for Pb content identified several major limitations, which continued to be reported on for decades, including the unknown volume of blood deposited, the tendency of red blood cells to accumulate at the periphery of the spot and contamination errors. The historical literature on DBS blood Pb measurement is replete with competing claims for success as well as reports on the limitations for screening and diagnostic purposes. The range of spectroscopic techniques used to measure Pb in DBS includes atomic absorption Spectrometry and Inorganic Mass Spectrometry. There is a broad consensus that the analysis of archived DBS samples from newborn screening programs suffers from sporadic background contamination for many elements, the magnitude of which makes such samples unreliable for biomonitoring studies. Yet, the introduction of Inorganic Mass Spectrometry into clinical laboratories provides the potential for multielement analysis of DBS. For some elements that are present at relatively high concentrations, such as Ca, Cs, Cu, Fe, K, Mg, Na, P, Rb, S and Zn, reasonable data may be feasible on archived DBS that are stored appropriately. However, for biomonitoring studies, analysis of DBS for many trace elements is fraught with contamination errors, inadequate limits of detection and a lack of well validated field-based studies. This is particularly true for Pb, Cd and Hg, for which only crude screening for acutely elevated levels can be useful. But for other elements such as Cu, Zn, Se, there may well be some value in using prospectively collected DBS to obtain population-based data. More recent developments with volumetric absorptive devices and microfluidic devices address some of the limitations inherent in DBS analysis and hold more promise for achieving reliable measurements of elemental content, but more work is needed to characterize background contamination, especially under real-world field conditions. In conjunction with well established capillary blood collection devices, these new technologies may provide better approaches to obtaining reliable environmental exposure information in the future for prospectively collected samples in population-based studies.

  • Development and Characterization of Reference Materials for Trace Element Analysis of Keratinized Matrices
    Analytical and bioanalytical chemistry, 2020
    Co-Authors: Mina W. Tehrani, Karl X. Yang, Patrick J. Parsons
    Abstract:

    Biomonitoring for human exposure to lead, arsenic, mercury, and other toxic metal(loid)s often relies on analyzing traditional biospecimens such as blood and urine. While biomonitoring based on blood and urine is well-established, non-traditional biospecimens such as hair and nails can offer the potential to explore past exposures as well as the advantages of non-invasive collection and ease of storage. The present study describes the production of four reference materials (NYS RMs 18-01 through 18-04) based on caprine horn, a keratinized tissue similar to human hair and nails, intended to serve as a resource for calibration, quality control, and method validation purposes. The elemental content and homogeneity of these candidate reference materials were characterized for 17 elements using inductively coupled plasma Mass Spectrometry (ICP-MS). Commutability between two or more of the NYS caprine horn RMs and human nails was established for 8 elements (Ba, Ca, Cr, Cu, Mn, Pb, Sr, and Zn) based on analysis by ICP-MS/MS and ICP-optical emission Spectrometry. The development and optimization of an ICP-MS/MS instrumental method for the determination of 17 elements in keratinized tissues is described. The method was validated against three certified reference materials based on human hair showing good accuracy and method repeatability better than 25% for all analytes. This study also describes sample preparation issues and addresses common challenges including surface contamination, microwave digestion, matrix effects, and spectral interferences in Inorganic Mass Spectrometry. New York State Department of Health Keratin Matrix Reference Materials. Graphical abstract.

  • Ultra-trace element analysis of human follicular fluid by ICP-MS/MS: pre-analytical challenges, contamination control, and matrix effects
    Journal of analytical atomic spectrometry, 2019
    Co-Authors: Aubrey L. Galusha, Aubreian C Haig, Michael S. Bloom, Pamela C. Kruger, Alexandra Mcgough, Nikolaus Lenhart, Rebecca Wong, Victor Y. Fujimoto, Evelyn Mok-lin, Patrick J. Parsons
    Abstract:

    Follicular fluid (FF), which is the fluid that envelops the developing oocyte (egg cell) in the ovary, can be analyzed to assess trace element content as well as to determine potential exposure to toxic elements in women seeking in vitro fertilization (IVF) treatment. Such measurements may be useful in establishing associations with potential adverse effects on oocyte viability and subsequent pregnancy outcomes. The principal goal of this study was to leverage the next generation of Inorganic Mass Spectrometry based on ICP-MS/MS to address the numerous analytical challenges of (ultra-)trace element analysis of human FF specimens. Ultra-trace element measurements are defined by the Clinical Laboratory Standards Institute as fluid concentrations below 10 μg L-1 or tissue Mass fractions below 1 μg g-1. Stringent pre-analytical procedures were developed to minimize exogenous contamination during FF specimen collection and storage in a prospective study of 56 women seeking IVF treatment. ICP-MS/MS instrumental parameters were carefully optimized, and the method validated for 11 biologically important elements that included 4 at trace levels (Cu, Se, Sr, and Zn) and 7 at ultra-trace levels (As, Cd, Co, Mo, Mn, Hg, and Pb). Method limits of detection (LODs) for ultra-trace elements varied from 5.6 ng L-1 for Cd to 0.11 μg L-1 for Mo. A total of 197 human FF specimens were analyzed using the proposed ICP-MS/MS method with 84% of specimens detectable for Pb and 100% detectable for Co, Cu, Mn, Mo, Sr, and Zn. The method based on ICP-MS/MS was compared to a previous method developed for FF using SF-ICP-MS.

  • Trace element analysis of human urine collected after administration of Gd-based MRI contrast agents: characterizing spectral interferences using Inorganic Mass Spectrometry.
    Journal of analytical atomic spectrometry, 2013
    Co-Authors: Amy J. Steuerwald, John G. Arnason, Patrick J. Parsons, Zhen Chen, C. Matthew Peterson, Germaine M. Buck Louis
    Abstract:

    Analysis of human urine is commonly used in biomonitoring studies to assess exposure to essential (e.g., Cu, Zn, Se) and non-essential (Pb, Cd, Pt) trace elements. These data are also used in epidemiological studies to evaluate potential associations between trace element exposure and various health outcomes within a population. Today most trace element analyses are typically performed using quadrupole-based inductively coupled plasma Mass Spectrometry (Q-ICP-MS). However, there is always the potential for spectral interferences with Q-ICP-MS instrumentation, especially when analyzing human specimens that may contain medications and other exogenous substances. Moreover, such xenobiotics may be unknown to the investigators. In a recent study focusing on environmental exposures and endometriosis: Endometriosis: Natural History, Diagnosis, and Outcomes (ENDO Study), urine specimens (n=619) were collected from participating women upon enrollment into the study or prior to surgery or pelvic magnetic resonance imaging (MRI), and analyzed for 21 trace elements by Q-ICP-MS. Here we report on some anomalous results observed for Se and Pt with elevated concentrations up to several orders of magnitude greater than what might be expected based on established reference intervals. Further investigations using Sector Field (SF-) ICP-MS instrumentation led to identification of doubly charged and polyatomic gadolinium (Gd) species traced to a Gd-based contrast agent that was administered to some subjects just prior to urine collection. Specifically, interferences from Gd2+ and several minor polyatomics were identified as interferences on all of the major isotopes of Se including 74Se, 76Se, 77Se, 78Se, 80Se, and 82Se. While trace amounts of Pt were present in the urine, a number of Gd-containing polyatomic species were also evident as major interferences on all isotopes of Pt (190Pt, 192Pt, 194Pt, 195Pt, 196Pt, and 198Pt), including Gd-chlorides, Gd-argides, and Gd-oxides. These observations underscore the importance of considering potential isobaric interferences when interpreting unusual trace element results for clinical specimens.

  • Monitoring Mn in whole blood and urine: a comparison between electrothermal atomic absorption and Inorganic Mass Spectrometry
    Journal of Analytical Atomic Spectrometry, 2011
    Co-Authors: Meredith L. Praamsma, John G. Arnason, Patrick J. Parsons
    Abstract:

    Measurements of Mn in blood and urine are used in biomonitoring studies as biomarkers of exposure. We compared methods for determining Mn, including graphite furnace atomic absorption Spectrometry (GFAAS), quadrupole-based inductively coupled plasma Mass Spectrometry (Q-ICP-MS) (standard and dynamic reaction cell (DRC) mode), and sector field (SF-) ICP-MS. We investigated polyatomic interferences in ICP-MS that can affect Mn measurements in blood and urine matrices, especially at concentrations associated with biomonitoring studies. Method detection limits (3SD) for blood (and urine) Mn were 1.5 (2.1) µg L−1 for GFAAS, 0.6 (0.5) µg L−1 for SF-ICP-MS, 1.0 (0.5) µg L−1 for DRC-ICP-MS and 6.4 (0.6) µg L−1 for Q-ICP-MS operated in standard mode. Method reproducibility for blood (22 µg L−1Mn) and urine matrices (9 µg L−1Mn) was found to be between 3 and 4% RSD for all methods, except for blood Mn by Q-ICP-MS (11% RSD) and urine Mn by GFAAS (7% RSD). Accuracy was assessed using various reference materials. Careful optimization of the DRC mode is required with blood because, in addition to polyatomic interferences, a large amount of Fe causes spectral overlap on Mn. GFAAS, DRC-ICP-MS and SF-ICP-MS methods show good agreement for Mn in urine and blood across the clinical range studied and, when properly optimized, are suitable for monitoring Mn in blood and urine. In contrast, Q-ICP-MS in standard mode exhibits a positive bias of ∼1 µg L−1 in urine and ∼4 µg L−1 in blood with respect to the other three methods investigated. The implications of this work are important when biomonitoring studies are compared and reference ranges are established.

Norbert Kávási - One of the best experts on this subject based on the ideXlab platform.

  • Accurate and precise determination of 90Sr at femtogram level in IAEA proficiency test using Thermal Ionization Mass Spectrometry.
    Scientific reports, 2019
    Co-Authors: Norbert Kávási, Sarata Kumar Sahoo, Tatsuo Aono, Hideki Arae, Zenon Palacz
    Abstract:

    A novel method for the determination of ultra-trace level 90Sr has been recently developed applying thermal ionization Mass Spectrometry (TIMS). The method includes the chemical separation of Zr (isobaric interference of 90Zr) from the samples followed by determination of 90Sr/88Sr abundance  sensitivity (2.1 × 10−10). The analytical performance of this method was assessed in the IAEA-TEL 2017-3 worldwide open proficiency test. For 90Sr determination, tap water and milk powder samples were distributed amongst the participant laboratories with reference values of 11.2 ± 0.3 Bq kg−1 (2.2 ± 0.1 fg g−1) and 99.9 ± 5.0 Bq kg−1 (19.5 ± 1.0 fg g−1), respectively. The stable Sr concentrations were 39.4 ± 0.9 ng g−1 and 2.5 ± 0.1 µg g−1 while the 90Sr/88Sr isotope ratios were 6.47 ± 0.17 × 10−8 and 9.04 ± 0.45 × 10−9 in the tap water and milk powder samples, respectively. For TIMS measurement, 50 mL water and 1 g milk powder samples were taken for analysis. This TIMS method demonstrated an impressive accuracy (relative bias of 4.2% and −2.1%, respectively) and precision (relative combined uncertainty of 4.1% and 7.6%, respectively) when compared with radiometric techniques. For the first time in the history of Inorganic Mass-Spectrometry, 90Sr analysis using a TIMS instrument is confirmed by an independent proficiency test.

  • Accurate and precise determination of ^90Sr at femtogram level in IAEA proficiency test using Thermal Ionization Mass Spectrometry
    Scientific Reports, 2019
    Co-Authors: Norbert Kávási, Sarata Kumar Sahoo, Tatsuo Aono, Hideki Arae, Zenon Palacz
    Abstract:

    A novel method for the determination of ultra-trace level ^90Sr has been recently developed applying thermal ionization Mass Spectrometry (TIMS). The method includes the chemical separation of Zr (isobaric interference of ^90Zr) from the samples followed by determination of ^90Sr/^88Sr abundance  sensitivity (2.1 × 10^−10). The analytical performance of this method was assessed in the IAEA-TEL 2017-3 worldwide open proficiency test. For ^90Sr determination, tap water and milk powder samples were distributed amongst the participant laboratories with reference values of 11.2 ± 0.3 Bq kg^−1 (2.2 ± 0.1 fg g^−1) and 99.9 ± 5.0 Bq kg^−1 (19.5 ± 1.0 fg g^−1), respectively. The stable Sr concentrations were 39.4 ± 0.9 ng g^−1 and 2.5 ± 0.1 µg g^−1 while the ^90Sr/^88Sr isotope ratios were 6.47 ± 0.17 × 10^−8 and 9.04 ± 0.45 × 10^−9 in the tap water and milk powder samples, respectively. For TIMS measurement, 50 mL water and 1 g milk powder samples were taken for analysis. This TIMS method demonstrated an impressive accuracy (relative bias of 4.2% and −2.1%, respectively) and precision (relative combined uncertainty of 4.1% and 7.6%, respectively) when compared with radiometric techniques. For the first time in the history of Inorganic Mass-Spectrometry, ^90Sr analysis using a TIMS instrument is confirmed by an independent proficiency test.

  • Zirconium decontamination factor test on DGA and Sr resin for 90 Sr analysis using Inorganic Mass Spectrometry
    Journal of Radioanalytical and Nuclear Chemistry, 2018
    Co-Authors: Norbert Kávási, Sarata Kumar Sahoo, Tatsuo Aono
    Abstract:

    The stable 90Zr isotope causes isobaric interferences with 90Sr determination during Inorganic Mass Spectrometry applications. To avoid interference of 90Zr, chemical separation of Zr from Sr is carried out using extraction chromatography resins. In this study, Zr decontamination factors were determined with Eichrom DGA and Sr resins. The Zr decontamination factor of Sr resin (~ 104) was one magnitude higher than DGA’s (~ 103). The recovery of Sr was around 90% in both resins. In a combination of two separation steps either using DGA-Sr resin or Sr–Sr resin, a Zr decontamination level of 107–108 could be achieved.

Takafumi Hirata - One of the best experts on this subject based on the ideXlab platform.

  • Heavy element stable isotope ratios : analytical approaches and applications
    Analytical and Bioanalytical Chemistry, 2013
    Co-Authors: Masaharu Tanimizu, Yoshiki Sohrin, Takafumi Hirata
    Abstract:

    Continuous developments in Inorganic Mass Spectrometry techniques, including a combination of an inductively coupled plasma ion source and a magnetic sector-based Mass spectrometer equipped with a multiple-collector array, have revolutionized the precision of isotope ratio measurements, and applications of Inorganic Mass Spectrometry for biochemistry, geochemistry, and marine chemistry are beginning to appear on the horizon. Series of pioneering studies have revealed that natural stable isotope fractionations of many elements heavier than S (e.g., Fe, Cu, Zn, Sr, Ce, Nd, Mo, Cd, W, Tl, and U) are common on Earth, and it had been widely recognized that most physicochemical reactions or biochemical processes induce Mass-dependent isotope fractionation. The variations in isotope ratios of the heavy elements can provide new insights into past and present biochemical and geochemical processes. To achieve this, the analytical community is actively solving problems such as spectral interference, Mass discrimination drift, chemical separation and purification, and reduction of the contamination of analytes. This article describes data calibration and standardization protocols to allow interlaboratory comparisons or to maintain traceability of data, and basic principles of isotope fractionation in nature, together with high-selectivity and high-yield chemical separation and purification techniques for stable isotope studies. Figure Isotope ratios of the elements can vary through almost all the chemical and biochemical reactions in nature

  • Heavy element stable isotope ratios: analytical approaches and applications.
    Analytical and bioanalytical chemistry, 2013
    Co-Authors: Masaharu Tanimizu, Yoshiki Sohrin, Takafumi Hirata
    Abstract:

    Continuous developments in Inorganic Mass Spectrometry techniques, including a combination of an inductively coupled plasma ion source and a magnetic sector-based Mass spectrometer equipped with a multiple-collector array, have revolutionized the precision of isotope ratio measurements, and applications of Inorganic Mass Spectrometry for biochemistry, geochemistry, and marine chemistry are beginning to appear on the horizon. Series of pioneering studies have revealed that natural stable isotope fractionations of many elements heavier than S (e.g., Fe, Cu, Zn, Sr, Ce, Nd, Mo, Cd, W, Tl, and U) are common on Earth, and it had been widely recognized that most physicochemical reactions or biochemical processes induce Mass-dependent isotope fractionation. The variations in isotope ratios of the heavy elements can provide new insights into past and present biochemical and geochemical processes. To achieve this, the analytical community is actively solving problems such as spectral interference, Mass discrimination drift, chemical separation and purification, and reduction of the contamination of analytes. This article describes data calibration and standardization protocols to allow interlaboratory comparisons or to maintain traceability of data, and basic principles of isotope fractionation in nature, together with high-selectivity and high-yield chemical separation and purification techniques for stable isotope studies.

Tatsuo Aono - One of the best experts on this subject based on the ideXlab platform.

  • Accurate and precise determination of 90Sr at femtogram level in IAEA proficiency test using Thermal Ionization Mass Spectrometry.
    Scientific reports, 2019
    Co-Authors: Norbert Kávási, Sarata Kumar Sahoo, Tatsuo Aono, Hideki Arae, Zenon Palacz
    Abstract:

    A novel method for the determination of ultra-trace level 90Sr has been recently developed applying thermal ionization Mass Spectrometry (TIMS). The method includes the chemical separation of Zr (isobaric interference of 90Zr) from the samples followed by determination of 90Sr/88Sr abundance  sensitivity (2.1 × 10−10). The analytical performance of this method was assessed in the IAEA-TEL 2017-3 worldwide open proficiency test. For 90Sr determination, tap water and milk powder samples were distributed amongst the participant laboratories with reference values of 11.2 ± 0.3 Bq kg−1 (2.2 ± 0.1 fg g−1) and 99.9 ± 5.0 Bq kg−1 (19.5 ± 1.0 fg g−1), respectively. The stable Sr concentrations were 39.4 ± 0.9 ng g−1 and 2.5 ± 0.1 µg g−1 while the 90Sr/88Sr isotope ratios were 6.47 ± 0.17 × 10−8 and 9.04 ± 0.45 × 10−9 in the tap water and milk powder samples, respectively. For TIMS measurement, 50 mL water and 1 g milk powder samples were taken for analysis. This TIMS method demonstrated an impressive accuracy (relative bias of 4.2% and −2.1%, respectively) and precision (relative combined uncertainty of 4.1% and 7.6%, respectively) when compared with radiometric techniques. For the first time in the history of Inorganic Mass-Spectrometry, 90Sr analysis using a TIMS instrument is confirmed by an independent proficiency test.

  • Accurate and precise determination of ^90Sr at femtogram level in IAEA proficiency test using Thermal Ionization Mass Spectrometry
    Scientific Reports, 2019
    Co-Authors: Norbert Kávási, Sarata Kumar Sahoo, Tatsuo Aono, Hideki Arae, Zenon Palacz
    Abstract:

    A novel method for the determination of ultra-trace level ^90Sr has been recently developed applying thermal ionization Mass Spectrometry (TIMS). The method includes the chemical separation of Zr (isobaric interference of ^90Zr) from the samples followed by determination of ^90Sr/^88Sr abundance  sensitivity (2.1 × 10^−10). The analytical performance of this method was assessed in the IAEA-TEL 2017-3 worldwide open proficiency test. For ^90Sr determination, tap water and milk powder samples were distributed amongst the participant laboratories with reference values of 11.2 ± 0.3 Bq kg^−1 (2.2 ± 0.1 fg g^−1) and 99.9 ± 5.0 Bq kg^−1 (19.5 ± 1.0 fg g^−1), respectively. The stable Sr concentrations were 39.4 ± 0.9 ng g^−1 and 2.5 ± 0.1 µg g^−1 while the ^90Sr/^88Sr isotope ratios were 6.47 ± 0.17 × 10^−8 and 9.04 ± 0.45 × 10^−9 in the tap water and milk powder samples, respectively. For TIMS measurement, 50 mL water and 1 g milk powder samples were taken for analysis. This TIMS method demonstrated an impressive accuracy (relative bias of 4.2% and −2.1%, respectively) and precision (relative combined uncertainty of 4.1% and 7.6%, respectively) when compared with radiometric techniques. For the first time in the history of Inorganic Mass-Spectrometry, ^90Sr analysis using a TIMS instrument is confirmed by an independent proficiency test.

  • Zirconium decontamination factor test on DGA and Sr resin for 90 Sr analysis using Inorganic Mass Spectrometry
    Journal of Radioanalytical and Nuclear Chemistry, 2018
    Co-Authors: Norbert Kávási, Sarata Kumar Sahoo, Tatsuo Aono
    Abstract:

    The stable 90Zr isotope causes isobaric interferences with 90Sr determination during Inorganic Mass Spectrometry applications. To avoid interference of 90Zr, chemical separation of Zr from Sr is carried out using extraction chromatography resins. In this study, Zr decontamination factors were determined with Eichrom DGA and Sr resins. The Zr decontamination factor of Sr resin (~ 104) was one magnitude higher than DGA’s (~ 103). The recovery of Sr was around 90% in both resins. In a combination of two separation steps either using DGA-Sr resin or Sr–Sr resin, a Zr decontamination level of 107–108 could be achieved.

Zenon Palacz - One of the best experts on this subject based on the ideXlab platform.

  • Accurate and precise determination of ^90Sr at femtogram level in IAEA proficiency test using Thermal Ionization Mass Spectrometry
    Scientific Reports, 2019
    Co-Authors: Norbert Kávási, Sarata Kumar Sahoo, Tatsuo Aono, Hideki Arae, Zenon Palacz
    Abstract:

    A novel method for the determination of ultra-trace level ^90Sr has been recently developed applying thermal ionization Mass Spectrometry (TIMS). The method includes the chemical separation of Zr (isobaric interference of ^90Zr) from the samples followed by determination of ^90Sr/^88Sr abundance  sensitivity (2.1 × 10^−10). The analytical performance of this method was assessed in the IAEA-TEL 2017-3 worldwide open proficiency test. For ^90Sr determination, tap water and milk powder samples were distributed amongst the participant laboratories with reference values of 11.2 ± 0.3 Bq kg^−1 (2.2 ± 0.1 fg g^−1) and 99.9 ± 5.0 Bq kg^−1 (19.5 ± 1.0 fg g^−1), respectively. The stable Sr concentrations were 39.4 ± 0.9 ng g^−1 and 2.5 ± 0.1 µg g^−1 while the ^90Sr/^88Sr isotope ratios were 6.47 ± 0.17 × 10^−8 and 9.04 ± 0.45 × 10^−9 in the tap water and milk powder samples, respectively. For TIMS measurement, 50 mL water and 1 g milk powder samples were taken for analysis. This TIMS method demonstrated an impressive accuracy (relative bias of 4.2% and −2.1%, respectively) and precision (relative combined uncertainty of 4.1% and 7.6%, respectively) when compared with radiometric techniques. For the first time in the history of Inorganic Mass-Spectrometry, ^90Sr analysis using a TIMS instrument is confirmed by an independent proficiency test.

  • Accurate and precise determination of 90Sr at femtogram level in IAEA proficiency test using Thermal Ionization Mass Spectrometry.
    Scientific reports, 2019
    Co-Authors: Norbert Kávási, Sarata Kumar Sahoo, Tatsuo Aono, Hideki Arae, Zenon Palacz
    Abstract:

    A novel method for the determination of ultra-trace level 90Sr has been recently developed applying thermal ionization Mass Spectrometry (TIMS). The method includes the chemical separation of Zr (isobaric interference of 90Zr) from the samples followed by determination of 90Sr/88Sr abundance  sensitivity (2.1 × 10−10). The analytical performance of this method was assessed in the IAEA-TEL 2017-3 worldwide open proficiency test. For 90Sr determination, tap water and milk powder samples were distributed amongst the participant laboratories with reference values of 11.2 ± 0.3 Bq kg−1 (2.2 ± 0.1 fg g−1) and 99.9 ± 5.0 Bq kg−1 (19.5 ± 1.0 fg g−1), respectively. The stable Sr concentrations were 39.4 ± 0.9 ng g−1 and 2.5 ± 0.1 µg g−1 while the 90Sr/88Sr isotope ratios were 6.47 ± 0.17 × 10−8 and 9.04 ± 0.45 × 10−9 in the tap water and milk powder samples, respectively. For TIMS measurement, 50 mL water and 1 g milk powder samples were taken for analysis. This TIMS method demonstrated an impressive accuracy (relative bias of 4.2% and −2.1%, respectively) and precision (relative combined uncertainty of 4.1% and 7.6%, respectively) when compared with radiometric techniques. For the first time in the history of Inorganic Mass-Spectrometry, 90Sr analysis using a TIMS instrument is confirmed by an independent proficiency test.