双道氢化物发生-原子荧光光谱法同时测定核电用钢中痕量砷和锑

Simultaneous determination of trace amount of arsenic and antimony in steels used for nuclear power by twin-channel HG-AFS

建立了双道氢化物发生-原子荧光光谱法同时测定核电用钢中痕量砷和锑的新方法。用王水溶解样品,以2.0 g/L L-半胱氨酸溶液作为预还原剂,在低酸度条件下实现对砷、锑的预还原。用20 g/L硼氢化钾溶液作为还原剂,氢化物发生反应在0.5 mol/L乙酸介质中进行。砷、锑的质量浓度在40μg/L范围与相应的荧光强度呈线性关系,方法的检出限(3s/k)分别为0.032μg/L和0.022μg/L。应用此方法同时测定了核电用钢及不锈钢标准样品中的砷锑含量,并与电感耦合等离子体原子发射光谱法的分析结果作了对比,测定值与标准样品的标准值相符,结果的相对标准偏差(n=8)均小于5.0%。

Trace amount of arsenic and antimony in nuclear power steels were simultaneously determined by twin-channel HG-AFS.Samples were dissolved with aqua regia.2.0 g/L L-cysteine was used as a pre-reducing agent and it can pre-reduce As（V） and Sb（V） to As（III） and Sb（III） in a low acidity.20 g/L potassium borohydride was used as a reductant.The hydride generation was carried out in a medium of 0.5 mol/L acetic acid.Linear relationship between values of fluorescence intensity and mass concentration of arsenic and antimony was kept in the range within 40 μg/L,with detection limit（3s/k） of 0.032 μg/L and 0.022 μg/L respectively.The proposed method was applied to the determination of trace amounts of arsenic and antimony in samples of nuclear power steels and certified reference materials of stainless steels.The results obtained were in consistent with the certified values and also with the results found by ICP-AES,and RSDs（n=8）were less than 5.0%.