低温等离子体原子荧光光谱法直接测定固体样品中的汞

摘要

A method for the determination of mercury in solid samples based on the low temperate plasma (LTP) coupled with atomic fluorescence spectrometric(AFS) technique was developed. The LTP was generated by the dielectric barrier discharge (DBD) to create mercury vapor, which was analyzed by AFS. The characteristics of the experimental parameters, including discharge power of 16-18 W, flow rates of discharge gas of 400 mL/min, sample distance of 1-5 mm and observation height of AFS of 10 mm, were studied, and the analytical performances of the present method were evaluated. Under the optimized conditions, the detection limit of Hg was 0. 91 mg/kg. A linear range from 91. 5 to 1096 mg/kg and a precision of 1. 9% -2. 3% (n=7) were achieved by using this proposed method. The accuracy of this method was verified by determining Hg in the reference materials and practice materials. The LTP-AFS method, without any reagent as the most important advantages, was considered as a simple, at atmospheric pressure and fast way to analysis mercury.%建立了低温等离子体(LTP)与原子荧光光谱仪(AFS)联用直接检测ABS固体样品中Hg的方法.实验采用介质阻挡放电(DBD)方式产生低温等离子体,剥蚀固体样品后产生的元素蒸气引入到原子荧光光谱仪进行检测.优化的实验条件为:DBD外接电源的放电功率为16～18 W,放电气体流速为400 mL/min;采样距离为1～5 mm;原子荧光光谱仪的原子化器高度为10 mm.本系统测定Hg的检出限为0.91 mg/kg,线性范围为91.5～1096 mg/kg;精密度(RSD,n=7)为1.9％～2.3％,并对标准样品以及实际样品进行测定,测定结果与标准值与ICPMS及CVG-AFS一致,表明本方法可作为直接检测固体样品的新型元素分析技术.