High-precision determination of 238U/235U isotope ratio in rocks by multicollector inductively coupled plasma mass spectrometry

T15N1

G.V. Mandzhieva, A.S. Sadasyuk, I.V. Chernyshev, K.N. Shatagin, A.V. Chugaev, B.I. Gareev

The paper describes high-precision U-isotope analysis of rocks. The analysis is based on the multi-collector inductively-coupled plasma mass spectrometry (MC-ICP-MS) and includes, as an essential part, a three-stage ion-exchange chromatography uranium separation from chemically complex solutions. In the analysis, the 235U and 238U mass-bias of the  MC-ICP-MS is corrected against the reference ratio of 233U and 236U in a double-spike added. The double-spiking precedes sample chemical digestion. This approach is useful as it corrects isotope data for a possible U-isotope fractionation that could have occurred during chemical preparation of samples. The double-spike 236U/233U is 1.03183 ± 0.00005. The extraction procedure allows more than 80% uranium yield. Accuracy of the analysis was estimated by the study of 238U/235U in international standard sample IRMM-3184 as well as in monitor samples. The uncertainty is estimated to be ± 0.008% (2SD) which is comparable to the accuracy of the results previously published by foreign researches.The analysis was elaborated for studying natural 238U/235U ratio variations. It is used by the authors for high-precision U-isotope composition determination in rocks (granites, shales, volcanic rocks) and U-bearing minerals.

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New method of mathematical correction of the results of analysis, obtained by inductively coupled plasma mass spectrometry, allowing the elimination of a double charged ions interference

T13N3

K.I. Chervyakovskii

A new method of mathematical correction of the results of analysis, obtained by inductively coupled plasma mass spectrometry, for elimination of a doubly charged ions interference based on the use the isotope signal registration in two spectrometer operation modes: in standard one and with using the collision cell was proposed. Mathematical correction of the results of arsenic determination in the model solutions was performed with the aid of two process: standard and proposed in this paper. The comparison of the results accuracy and repeatability was conducted.

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Определение содержания примесей в урановых материалах методом масс-спектрометрии с индуктивно связанной плазмой

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Некоторые вопросы оценки погрешностей масс-спектрометрических измерений

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Определение элементов B, Si, P, S, Cl и Br в урановых материалах

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Определение редкоземельных элементов в геологических объектах

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Применение высокого разрешения и динамической реакционной ячейки для повышения чувствительности прямого определения кремния

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Изотопный анализ стронция методом многоколлекторной масс-спектрометрии

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Определение редкоземельных элементов методом масс-спектрометрии с индуктивно связанной плазмой

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(Русский) Интерференции полиатомных и двухзарядных ионов

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