کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5130628 | 1490844 | 2017 | 7 صفحه PDF | دانلود رایگان |

- Accurate analysis of δ34S and Î33S with 2 SD precision of ±0.18â° and ±0.10â° by using 3 nmol S.
- Quantification of S losses during sample pretreatment and membrane desolvation.
- Improved S memory reduction and blank evaluation by adding adequate Na to the washing solution.
- Successful application to low-S marine sediment pore fluids.
We propose an improved method for precise sulfur isotopic measurements by multi-collector inductively coupled plasma mass spectrometry (MC-ICP-MS) in conjunction with a membrane desolvation nebulization system. The problems of sulfur loss through the membrane desolvation apparatus are carefully quantified and resolved. The method overcomes low intrinsic sulfur transmission through the instrument, which was initially 1% when operating at a desolvation temperature of 160 °C. Sulfur loss through the membrane desolvation apparatus was resolved by doping with sodium. A Na/S ratio of 2 mol molâ1 produced sulfur transmissions with 98% recovery. Samples of 3 nmol (100 ng) sulfur achieved an external precision of ±0.18â° (2 SD) for δ34S and ±0.10â° (2 SD) for Î33S (uppercase delta expresses the extent of mass-independent isotopic fractionation). Measurements made on certified reference materials and in-house standards demonstrate analytical accuracy and reproducibility. We applied the method to examine microbial-induced sulfur transformation in marine sediment pore waters from the sulfate-methane transition zone. The technique is quite versatile, and can be applied to a range of materials, including natural waters and minerals.
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Journal: Analytica Chimica Acta - Volume 988, 2 October 2017, Pages 34-40