Simó R
Institut de Ciències del Mar, ICM-CSIC, Barcelona, Spain.
J Chromatogr A. 1998 May 22;807(2):151-64. doi: 10.1016/s0021-9673(98)00086-7.
Dimethyl sulfoxide (DMSO) occurs in the environment as a result of a number of biogenic and anthropogenic production and emission processes. It is an environmentally significant compound because of its use as a substrate by bacteria and its potential role in the biogeochemical cycle of dimethyl sulfide (DMS), a climatically active trace gas. In this paper, current methods for DMSO determination at nanomolar levels in natural waters, all involving gas chromatography, are reviewed. Direct injection and separation of aqueous DMSO offers a simple and fast application, but exhibits limited sensitivity due to limitation on injection volumes. So far, most authors have preferred DMSO reduction and subsequent analysis of the evolved DMS by purge-and-trap preconcentration and flame photometric detection. Several reducing agents have been used, though some require cumbersome procedures or are very sensitive to operational conditions. The common algal component dimethylsulfoniopropionate (DMSP) acts as an interference in some reduction methods and, therefore, either DMSP elimination prior to DMSO analysis or correction a posteriori is required. DMSO can be analyzed along with DMS, methanethiol, dimethyl disulfide and DMSP in the same water sample, either sequentially or separately, so that comprehensive speciation of methylated sulfur is obtained. Owing to the biological activity of DMSO, appropriate water sampling and handling procedures must be applied. Acidification and freezing appear to be suitable for aqueous DMSO storage, although immediate analysis in the field is always preferable. Future directions of DMSO determination in aquatic environments are suggested.
二甲基亚砜（DMSO）由于多种生物源和人为源的生产及排放过程而存在于环境中。它是一种对环境具有重要意义的化合物，因为细菌将其用作底物，并且它在二甲基硫醚（DMS，一种对气候有影响的痕量气体）的生物地球化学循环中具有潜在作用。本文综述了目前在天然水中纳摩尔水平测定DMSO的方法，所有方法均涉及气相色谱法。直接进样和分离水性DMSO提供了一种简单快速的应用，但由于进样体积的限制，灵敏度有限。到目前为止，大多数作者倾向于将DMSO还原，然后通过吹扫捕集预浓缩和火焰光度检测对生成的DMS进行分析。已经使用了几种还原剂，不过有些需要繁琐的程序，或者对操作条件非常敏感。常见的藻类成分二甲基磺基丙酸酯（DMSP）在某些还原方法中会产生干扰，因此，要么在分析DMSO之前消除DMSP，要么事后进行校正。DMSO可以与DMS、甲硫醇、二甲基二硫和DMSP在同一水样中依次或分别进行分析，从而实现甲基化硫的全面形态分析。由于DMSO具有生物活性，必须采用适当的水样采集和处理程序。酸化和冷冻似乎适合水性DMSO的储存，不过总是优先在现场立即进行分析。文中还提出了水生环境中DMSO测定的未来发展方向。
