砷是一种在自然环境中普遍存在的元素,环境中的砷污染问题已引起社会各界的广泛关注。砷的毒性与砷的赋存形态密切相关,而不同形态砷的毒性相差甚远。因此,砷的形态分析对于砷在环境中的迁移转化研究及其健康风险评价都具有重要意义。其中样品前处理是砷形态分析的基础,样品的保存和固体样品中砷形态提取方法尤为关键,但遗憾的是迄今还没有一种统一而有效的方法。强提取剂能够保证较高的提取率,但可能会造成提取过程中样品中原有砷形态的改变;弱提取剂能够保证砷形态不被改变,但存在提取率不高的不足;优化选择提取剂和辅助提取过程以保证砷形态高提取率和高回收率是开展砷的生态与健康风险研究的基础。该文综述了砷形态分析中样品前处理技术进展,着重介绍了水溶液的保存条件以及不同砷形态的提取方式。
Arsenic(As) is a ubiquitous element in the ecosystem and environment,and present in different chemical species.The toxicity of these arsenic compounds varies dramatically by several orders of magnitude according to oxidation state,chemical form and physical state and factors. It is imperative to identify and quantify individual arsenic species for the sake of understanding the biogeochemistry, metabolism and toxic mechanisms of arsenic. It relies on an extraction procedure of arsenic species, which comprise critical steps for analyzing samples due to possible losses of analytes, a significant risk of transformation of species, or insufficient extraction of arsenic compounds that may result in poor or erroneous results. In this paper, the progress of pre-treatment techniques in this field during the latest decades was introduced. Particularly, the preservation of water samples was summarized.