HG-ICP-MS同时测定生物样品中痕量As,Se,Hg

以HNO3为介质,采用自行研制的二级气液分离器代替易消耗的膜分离器,在优化的实验条件下,采用HG-ICP-MS实现了As,Se,Hg的同时测定,分别获得了0.022,0.016,0.009 ngmL的检出限。实验研究了二级气液分离器中的气液分离行为、样品酸度、NaBH4质量浓度和引入方式等因素对测定灵敏度和精密度的影响。实验的结果表明,HG-ICP-MS同时测定As,Se,Hg的主要干扰来自于Fe,cu等过渡金属离子,样品溶液中抗坏血酸-硫脲的加入可以掩蔽这些离子的干扰。利用所建立的方法测定了人发、灌木叶和大米粉标样中痕量的As,Se,Hg,结果与标准参考值相符。

Simultaneous determination of trace amounts of As, Se and Hg in biological samples by HG-ICP-MS

An HG-ICP-MS method was developed to simultaneously determine trace amounts of As, Se and Hg in biological samples with HNO_3 as the acidic media. A home-made double-stage gas-liquid separator was used to replace the conventionaly used membrane separator. The behavior of the separator was studied in the gas liquid separating process. Detection limits of 0.022, 0.016 and 0.009 ng/ml for As, Se and Hg were obtained, respectively. Sample acidity, NaBH_4 concentration and sample introduction mode were investigated for their effects on sensitivity and precision. Experimental results showed that the main interference in the proposed HG-ICP-MS method was originated from transitional elements such as Fe and Cu. Addition of ascorbic acid-thiourea in the sample solution could mask these interferents. Trace amounts of As, Se and Hg in the national certified reference materials such as human hair, poplar leaves and rice powder were determined by the proposed method, and the results obtained were in good agreement with the certified values.