Abstract Deciphering the role of sulfur in biogeochemical cycles strongly relies on its stable isotope composition, which ultimately depends on the ability to quantitatively recover different sulfur species from geological samples. For decades most studies have been restricted to the 34S/32S composition of bulk samples, using simple methods based on the analysis of SO2 released by sample combustion combined to mass spectrometry. The wet chemistry procedures required to selectively extract specific sulfur species were generally avoided due to their tediousness and inefficiency for some complex matrices, especially when targeting organic sulfur. With the recent advent of multi-isotope studies (investigating the minor sulfur stable isotopes 33S and 36S) which rely either on the analysis of sulfur as SF6, or on the use of secondary ion or multi-collector inductively coupled plasma mass spectrometry, wet chemistry-based preparation procedures were brought back to the stage with a renewed interest in developing procedures better adapted to the investigation of specific sulfur species. Here we propose a new stepwise chemical procedure for the quantitative recovery and multi-isotope analysis of organic sulfur from both solvent soluble (total lipid extract) and insoluble (kerogen) fractions, based on a wet oxidation by sodium hypochlorite. This procedure also allows the multi-isotope analysis of inorganic sulfur species (elemental sulfur, sulfates and sulfides) in the same sample. Its application to different well-known petroleum source rocks and to an oil demonstrates its relevance for disentangling the interactions between the different sulfur pools and for shedding new light on the sulfur biogeochemical cycle.

中文翻译：

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用于（多）同位素分析的天然有机硫和矿物硫的定量和比回收率

摘要 硫在生物地球化学循环中的作用很大程度上取决于其稳定的同位素组成，而这最终取决于从地质样品中定量回收不同硫物种的能力。几十年来，大多数研究都仅限于散装样品的 34S/32S 组成，使用基于样品燃烧释放的 SO2 分析与质谱相结合的简单方法。选择性提取特定硫物质所需的湿化学程序通常被避免，因为它们对于某些复杂基质来说是乏味和低效的，尤其是在针对有机硫时。随着最近多同位素研究（研究微量硫稳定同位素 33S 和 36S）的出现，这些研究依赖于将硫作为 SF6 进行分析，或者在使用二次离子或多接收器电感耦合等离子体质谱法时，基于湿化学的制备程序重新回到了舞台上，重新关注开发更适合特定硫物质研究的程序。在这里，我们提出了一种新的逐步化学程序，用于从溶剂可溶（总脂质提取物）和不溶（干酪根）馏分中定量回收和多同位素分析有机硫，基于次氯酸钠的湿氧化。该程序还允许对同一样品中的无机硫物质（元素硫、硫酸盐和硫化物）进行多同位素分析。