采用氢化物发生-原子荧光光谱法测定低合金钢中砷的含量。样品经盐酸-硝酸混合酸消解,以盐酸(5+95)溶液为反应介质,15 g·L-1硼氢化钾-2 g·L-1氢氧化钾的混合溶液为还原剂,采用柠檬酸作为掩蔽剂。砷的质量浓度在60.0 μg·L-1以内与荧光强度呈线性关系,方法的检出限(3s/k)为0.023 μg·L-1。应用此法对标准钢样进行了分析,测定结果与认定值相符合,可满足钢铁中微量砷(质量分数0.001%~0.04%)的测定要求。

HG-AFS was applied to the determination of arsenic in low alloy steels. Sample was digested with mixed acid of HCl and HNO3, and determined in a medium of HCl (5+95) solution using the mixed solution of 15 g·L-1 KBH4 and 2 g·L-1 KOH as reducing reagent and citric acid as masking reagent. Linear relationship between values of fluorescence intensity and mass concentration of As was found in the range within 60.0 μg·L-1, with detection limit (3s/k) of 0.023 μg·L-1. The proposed method was applied to the analysis of 2 steel CRM′s, giving results in consistency with the standard values. This method was found to be feasible for the determination of trace amount of arsenic (w=0.001%~0.04%) in steel.