Affiliation:
1. Ministry of Natural Resources Key Laboratory of Metallogeny and Mineral Assessment, Institute of Mineral Resources Chinese Academy of Geological Sciences Beijing China
2. School of Earth and Space Sciences Peking University Beijing China
3. Drug and Food Anti‐Doping Laboratory China Anti‐Doping Agency Beijing China
Abstract
RationaleA novel laser ablation‐isotope ratio mass spectrometry (LA‐IRMS) method for in situ analysis of sulfur isotopes in sulfides has been developed. Instead of the in situ reaction applied by the traditional laser microprobe, the analyte gas preparation in this method is separated temporally and spatially from the LA, resulting in improved precision and accuracy.MethodsOur LA‐IRMS system combines an ultraviolet LA system, an elemental analyzer (EA), a custom‐built cryogenic concentration system, a continuous‐flow interface, and an IRMS. The sulfide aerosol particles generated from LA were transferred by a helium carrier gas from the ablation cell into the reaction tube and were then converted into SO2. Subsequently, SO2 was enriched in two cold traps and was finally introduced into the ion source of the IRMS through the continuous‐flow interface.ResultsWe measured three synthetic and four natural sulfide reference materials to test the performance of this method. Precisions of ±0.25‰–±0.48‰ and ±0.32‰–±0.64‰ (1SD, n = 5) for δ34S values of synthetic and natural sulfide standards can be obtained for spot sizes ranging from 64 to 80 μm. Measured values and their recommended values showed a good linear relationship (R2 within 0.998 and 0.9995) with the slope of approaching unity (within 1.0509 and 1.1313).ConclusionsData from the measurement of reference materials showed that the precision and accuracy of our method were satisfactory. This method is a powerful tool for in situ sulfur isotope measurement of sulfides and can be further applied to in situ carbon and oxygen isotope analyses.
Subject
Organic Chemistry,Spectroscopy,Analytical Chemistry