Sulfur (S) isotopes are used as a key tracer for ore-forming material sources in geochemical processes. Conventional bulk analysis techniques used for S isotopic measurements include gas-source isotope ratio mass spectrometry (IRMS) or solution MC-ICP-MS. IRMS is most commonly used for high precision S isotope measurements, although it requires large sample sizes and time-consuming sample preparation (to convert sulfur to gaseous SO2 or SF6 forms beforehand). Solution MC-ICP-MS, can provide good accuracy and high precision using a smaller amount of sulfur sample. Based on the solution MC-ICP-MS technique, laser ablation S isotopic measurements have been developed to provide spatial resolution information by distinguishing S isotopes of zonation within a single grain or multi-genesis minerals in micro-areas.
The study applies in-situ S isotopic measurements in sulfides using femtosecond laser ablation coupled with a Nu Plasma 1700 instrument. The figures show the S map using an electron probe, and the S isotopic measurement results.
The unique true high resolution feature of the Nu Plasma 1700 and its capability in retaining good transmission at high resolutions make it the instrument of choice for high precision LA-MC-ICP-MS measurements of S isotopes.
Data source: Chen et al., J. Anal. At. Spectrom., 2017, 32, 107