摘要:
砷元素的不同形态对人体有不同的毒性,无机砷的毒性最大,有机砷毒性较小,准确测定水体中尤其是地下水中砷形态的含量对于人体健康和环境保护有重要意义。但目前国内外尚缺乏地下水中砷形态的标准物质。文章研制了5个地下水砷形态标准物质,候选物样品采自山西和内蒙古高砷地区,在样品的采集和制备过程中使用冷冻干燥法和加保护剂两种方法保证砷形态稳定,定值参数为砷全量、As(Ⅲ)、As(Ⅴ),定值方法采用氢化物发生-原子荧光光谱法、电感耦合等离子体光谱法、电感耦合等离子体质谱法、高效液相色谱-电感耦合等离子体质谱法。经检验,制备的砷形态标准物质具有良好的均匀性和稳定性。该系列标准物质研制中首次应用冷冻干燥技术,样品保存问题得到了很好的解决,采用多家实验室协作定值,测试方法准确、可靠,标准值和不确定度合理,填补了国内外砷形态标准物质研制的空白。
Abstract:
Arsenic is widely found in nature. Different speciations have different toxicity, for example the toxicity of inorganic arsenic is larger than that of organic arsenic. Therefore, accurate determination of arsenic speciation in water, especially ground water, has important significance for human health and environmental protection. However, there is no arsenic speciation standard reference either nationally or internationally. To this end, five reference materials for arsenic speciation have been developed, which were collected from Shanxi Province and Nei Monggol, typical areas with a high background of arsenic. During collection and preparation of the samples, lyopyilization and protectant were used to ensure stability of the arsenic speciation. The certified content values of total arsenic, As(Ⅲ) and As(Ⅴ) were obtained by Atomic Fluorescence Spectrometry (AFS), Inductively Coupled Plasma-Atomic Emission Spectroscopy (ICP-AES), Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) and High Performance Liquid Chromatography-Inductively Coupled Plasma-Mass Spectrometry (HPLC-ICPMS). The analytical results indicate that the reference materials were homogeneous and stable. A multi-laboratory collaborative analysis scheme was adopted in the certification procedure. The determination methods were accurate and reliable with reasonable certified values and uncertainties. Moreover, lyopyilization, which is commonly used in the medical profession in order to guarantee the sample stability, was primarily applied to the preparation of the standard reference materials. This series of reference materials fills the gaps at national and international levels.
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