新型含砷水样前处理技术开发研究

砷是一种对人体健康造成严重伤害的污染物,受管理规定和检测手段的限制,由砷诱发癌症的风险仍然较高。选取离子液体作为萃取溶剂,开发出一种基于离子交换机理的分散液液微萃取方法,应用于含砷水样的前处理。通过研究水样体积、pH值、离子液体用量等6项关键因素对该方法萃取效率的影响,以及对该方法的表现效果进行了优化和评价。本方法可在数分钟内完成对砷的萃取,富集因子可达到210,在0.05～10 μg/L范围内均有较好线性关系,相对标准偏差仅为1.5%;当本方法与石墨炉原子吸收光谱仪联用时,对砷的检出限可达到10 ng/L。另外,避免了传统样品前处理方法中使用的大量有机溶剂,因此更加绿色、环保。研究结果为水环境分析监测技术领域的开拓和发展提供了新思路。

A Novel Method of Sample Pre-treatment for Extraction of Arsenite from Water

Inorganic arsenic has been identified as a harmful pollutant to human health. However, the regulated standard of arsenite concentration set by administration exposes people to relatively high risk, partially due to the limitation of analysis method. In this work, a dispersive liquid-liquid extraction method was developed and applied to the extraction of arsenite from water. Ionic liquids (ILs) were selected as extraction solvent. Effect of key factors including sample volume, pH value, and amount of ILs on the extraction efficiency of the proposed method were studied. By using the proposed method, the extraction of arsenite can be completed in minutes with the enrichment factor reaching 210 and a good linearity in the range of 0.05-10 μg/L under optimized condition, yet an error only 1.5%. When coupled with atomic absorption spectrometer equipped with graphite furnace atomizer, the limit of arsenite detection was found as low as 10 ng/L. In addition, the proposed method consumes little organic solvents, making it more environmental friendly