3-Mercaptohexanol and 4-methyl-4-mercaptopentanone are volatile thiols with a low perception threshold and are found in relatively low concentrations in several types of wines, e.g. Sauvignon blanc. They contribute positively to the flavour of a wine when in their free form, but they can oxidise, especially in the presence of Cu²⁺ and sulfur residues originating from pesticide treatments on the grapes. This condensation reaction results in the formation of polysulfides, which during storage can cause the release of H₂S: a compound known to give rise to off-flavour in wine. The formation of these polysulfides has been proposed to originate from cysteinyl and glutathionyl S-conjugate precursors, but they have not yet been characterised. In this work, a method using ultra-high-performance liquid chromatography coupled to high-resolution mass spectrometry and online solid-phase extraction was designed and optimised for detection of these S-conjugates. The method allowed the detection of 21 suspected symmetrical and asymmetrical S-conjugates in thiol-supplemented aqueous solutions, of which 17 were also recovered in supplemented synthetic musts and wines. Moreover, the proposed method was used to investigate polysulfide formation upon addition of two different types of sulfur. Differences in formation of S-conjugates were evident in the synthetic samples: a higher relative abundance was observed upon addition of wettable sulfur compared to washed sulfur. For the commercial wines, differences in polysulfide formation were minor and merely related to the differences between the wines and not to the type of sulfur added.

3-巯基己醇和4-甲基-4-巯基庚酮是挥发性硫醇，具有较低的感知阈值，并且在几种类型的葡萄酒中均以相对较低的浓度发现，例如长相思。当它们以游离形式存在时，它们对葡萄酒的风味有积极的贡献，但它们可以氧化，特别是在存在Cu ²⁺和源自农药处理葡萄的硫残留物的情况下。该缩合反应导致形成多硫化物，该多硫化物在储存期间可能导致H ₂释放S：一种已知会引起酒中异味的化合物。已经提出这些多硫化物的形成源自半胱氨酸和谷胱甘肽S-共轭物前体，但是尚未对其进行表征。在这项工作中，设计并优化了一种使用超高效液相色谱结合高分辨率质谱和在线固相萃取的方法来检测这些S-共轭物。该方法可以检测到补充了硫醇的水溶液中的21种疑似对称和不对称S-共轭物，其中17种还从补充的合成葡萄汁和葡萄酒中回收。此外，所提出的方法用于研究添加两种不同类型硫后多硫化物的形成。在合成样品中，S-缀合物形成的差异是明显的：与洗涤过的硫相比，在添加可湿性硫时观察到更高的相对丰度。对于商用葡萄酒，多硫化物形成的差异很小，仅与葡萄酒之间的差异有关，与添加的硫的类型无关。