TY - JOUR
T1 - Investigation of potential polyatomic interferences on uranium isotope ratio measurements for the LS-APGD-Orbitrap MS system
AU - Goodwin, Joseph V.
AU - Manard, Benjamin T.
AU - Ticknor, Brian W.
AU - Cable-Dunlap, Paula
AU - Kenneth Marcus, R.
N1 - Publisher Copyright:
© 2023 Elsevier B.V.
PY - 2024/1
Y1 - 2024/1
N2 - The determination of actinide (e.g., U and Pu) content and isotopics is of importance to the nuclear forensics and safeguards communities. However, in the analysis of environmental samples, such as those collected by the International Atomic Energy Agency, uranium measurements can be complicated by isobaric interferences from polyatomic variants of heavy elements (e.g., Pb). This leads to complex, time-consuming sample manipulations (i.e., separations) before determining isotope ratios. An alternative strategy to sample pretreatment is to use high-resolution mass spectrometric platforms during the analysis to fully resolve the uranium isotopes from potential polyatomic interferences, negating the need for prior chemical separation. The liquid sampling - atmospheric pressure glow discharge (LS-APGD) coupled with an Orbitrap mass spectrometer provides a high-resolution (>70,000 m/Δm at m/z 200) inorganic mass spectrometry platform. As a demonstration of the power of this instrumental platform, and indeed, the high-resolution approach in general, uranium isotope ratios were determined in the presence of elemental impurities (e.g., Pb, Pt, Ta, W) commonly encountered with environmental sample swipe analysis, without any prior treatment. Even at elemental impurity concentrations of 1000–5000× relative to uranium, no interference was observed with the 235U or 238U signal. In addition, the 235U/238U isotope ratio for the samples with the concomitants present are within 2 standard deviations of the values obtained without their addition, indicating that these impurities do not impact the determined uranium isotope ratio. These findings represent a significant first step in leveraging the high resolution of the LS-APGD-Orbitrap-MS to overcome isobaric and molecular interferences instead of relying on chemical separations.
AB - The determination of actinide (e.g., U and Pu) content and isotopics is of importance to the nuclear forensics and safeguards communities. However, in the analysis of environmental samples, such as those collected by the International Atomic Energy Agency, uranium measurements can be complicated by isobaric interferences from polyatomic variants of heavy elements (e.g., Pb). This leads to complex, time-consuming sample manipulations (i.e., separations) before determining isotope ratios. An alternative strategy to sample pretreatment is to use high-resolution mass spectrometric platforms during the analysis to fully resolve the uranium isotopes from potential polyatomic interferences, negating the need for prior chemical separation. The liquid sampling - atmospheric pressure glow discharge (LS-APGD) coupled with an Orbitrap mass spectrometer provides a high-resolution (>70,000 m/Δm at m/z 200) inorganic mass spectrometry platform. As a demonstration of the power of this instrumental platform, and indeed, the high-resolution approach in general, uranium isotope ratios were determined in the presence of elemental impurities (e.g., Pb, Pt, Ta, W) commonly encountered with environmental sample swipe analysis, without any prior treatment. Even at elemental impurity concentrations of 1000–5000× relative to uranium, no interference was observed with the 235U or 238U signal. In addition, the 235U/238U isotope ratio for the samples with the concomitants present are within 2 standard deviations of the values obtained without their addition, indicating that these impurities do not impact the determined uranium isotope ratio. These findings represent a significant first step in leveraging the high resolution of the LS-APGD-Orbitrap-MS to overcome isobaric and molecular interferences instead of relying on chemical separations.
KW - LS-APGD
KW - Mass spectrometry
KW - Nuclear
KW - Orbitrap
KW - Safeguards
KW - Uranium
UR - http://www.scopus.com/inward/record.url?scp=85177232891&partnerID=8YFLogxK
U2 - 10.1016/j.microc.2023.109645
DO - 10.1016/j.microc.2023.109645
M3 - Article
AN - SCOPUS:85177232891
SN - 0026-265X
VL - 196
JO - Microchemical Journal
JF - Microchemical Journal
M1 - 109645
ER -