聚环氧琥珀酸掩蔽基体—氢化物发生原子荧光光谱法测定铅锭中砷和汞

摘要

A simple method for simultaneous determination of As and Hg in lead ingot was developed based on hydride generation atomic fluorescence spectrometry (HG-AFS) with nitric acid dissolving samples and polyepoxysuccinic acid (PESA) masking matrix. The influences of sample dissolution method and PESA dosage on the determination results were investigated. The hydride generation conditions and instrumental operation parameters were optimized. The possible interference of coexisting elements was discussed. The results showed that 2. 0 mL of PESA could effectively mask Pb matrix after dissolving 0. 1 g of lead ingot. The coexisting elements in lead ingot including Ca, Cu, Sb and Sn did not interfere with the determination of As and Hg. The detection limits were 0. 070 jug/L for As and 0. 011 fig/L for Hg, respectively. The proposed method has been applied to the determination of actual samples. The relative standard deviations (RSD, n = 5) for As and Hg were 1. 0%-2. 0% and 1. 3%-l. 9%, respectively, and the recoveries were 96%-102% and 99%-103%, respectively.%采用硝酸分解样品,用聚环氧琥珀酸(PESA)掩蔽基体,建立了氢化物发生原子荧光光谱法(HG-AFS)测定铅锭中砷和汞的简单方法.研究了溶样方法和PESA用量对测定结果的影响,优化了氢化物发生条件及仪器的工作参数,考察了共存元素可能引起的干扰.实验表明,0.1g铅锭溶解后加入2.0 mL PESA可以有效地掩蔽基体元素Pb,铅锭中的Ca、Cu、Sb和Sn不干扰As和Hg的测定.砷和汞的方法检出限分别为0.070μg/L和0.011 μg/L.将方法应用于实际样品分析,砷和汞的相对标准偏差(RSD,n=5)分别在1.0％～2.0％和1.3％～1.9％之间,加标回收率分别为96％～102％和99％～103％.