顺序注射-氢化物发生-原子荧光光谱法测定矿石中砷和汞含量

Sequential Injection-HG-AFS Determination of Arsenic and Mercury in Ores

应用顺序注射-氢化物发生-原子荧光光谱法测定了矿石中砷和汞含量的方法。样品用盐酸和硝酸消解后，在消解液中加入盐酸羟胺以破坏消解时引入的氧化性试剂。将试样溶液转化为盐酸（2＋98）介质并以其作载流引入顺序注射分析系统，同时引入10g·L-1（测砷）和5g·L-1（测汞）硼氢化钾溶液作还原剂。砷和汞的质量浓度分别在100，10g·L-1以内与其荧光强度呈线性关系l方法的检出限（3s）依次为o．05，0．02g·L-1。方法用于铜精矿、锰矿和铁矿等样品分析，测定结果与认定值或已知值相符，相对标准偏差（，2=10）在0．93％～8．1％之间。

Sequential injection （SI）-HG-AFS was applied to the determination of As and Hg in ores. Sample of ores was digested with HC1 and HNOa and the solution obtained was treated with hydroxylamine hydrochloride to eliminate the action of oxidizing reagents introduced during sample digestion. Hydride of As and vapour of Hg were generated from HC1 （2--98） solution using solution of 10 g . L 1 （for As） and 5 g .L-1 （for Hg） KBH4 solution as reducing reagent. Linear relationships between the magnitude of fluorescence intensity and mass concentration of As and Hg were found in the ranges within 100 and 10 g L 1 , with detection limits （3s） of 0. 05 and 0. 02/g L 1 respectively. The proposed method was applied to the determination of As and Hg in samples of copper concentrate ores, manganese ores and iron ores, giving results in consistency with the certified or known values, and values of RSD＇s （n=10） obtained were in the range of 0. 93--8. 1.