铑作基体改进剂石墨炉原子吸收法测定海洋生物样品中的痕量砷

Determination of Trace Arsenic in Mussel, Shrimp Powder and Oyster by Zeeman Atomic Absorption Spectrometry with Rhodium as a Matrix Modifier

采用铑作基体改进剂，消除样品中共存磷酸盐基体的干扰，实现了用塞曼石墨炉原子吸收法测定贻贝、虾粉、牡蛎等海洋生物样品中痕量砷。方法的ＬＤ为２５ｐｇ（１０μＬ进样），线性范围在０～１２５μｇ／ＬＡｓ。标准加入法测定砷的回收率为８５％～１０２％，１０－６水平Ａｓ的测定ＲＳＤ（ｎ＝６）小于７％，分析结果与标准样品的标准值和氢化物原子吸收法测定结果相符。

A method for the determination of trace arsenic in mussel, shrimp powder and oyster by Zeeman graphite furnace atomic absorption spectrometry is developed. (NH 4) 3RhCl 6 and citric acid is used as a mixed matrix modifier to eliminate the interference from coexistent calcium phosphate. The recoveries of standard addition for As are 85%～102% with precision of less than 7% RSD ( n =6). The results of As in mussel, shrimp powder and oyster by this method are in a good agreement with certified values and those provided by hydride generation atomic absorption spectrometry.