原子荧光光度法测定天然水体中的Sb(Ⅴ)和Sb(Ⅲ)

摘要

采用氢化物-原子荧光光度法(HG-AFS),测定天然水体中的总溶解态无机锑(Sb(V+Ⅲ))和三价锑(Sb(c)).选择的最佳仪器条件为:灯电流60 mA,负高压-260 V,原子化器的温度190℃和氩气的载气流量600mL/min.Sb(V+Ⅲ)在1 mol/L HC1介质中进行测定,检出限为0.024μg/L,线性范围为0～14μg/L.对浓度0.3μg/L和0.03 μg/L的样品分析精密度分别为2.0%和1.9%(n=9),方法的回收率93.7%～105%.Sb(Ⅲ)是在柠檬酸和柠檬酸钠缓冲溶液(pH为4.0～4.5),辅以100 mL/min的氢气进行测定,测得检出限为0.0013μg/L,对浓度0.04 μg/L和0.01μg/L的样品分析精密度分别为3.8%和5.5%(n=9),方法的回收率91.1%～104%.二者在不同介质中工作曲线的斜率变动范围均小于5%.Sb(V)的含量由总溶解态无机锑与三价锑的含量差减得到.%A method for the determination of Sb (Ⅴ+Ⅲ) and Sb (Ⅲ) by atomic fluorescence spectrometry (AFS) in natural water was established in this study. The optimal instrumental parameters were electric current, 60 mA;voltage, -260 Ⅴ; temperature, 190 ℃; and Ar flux, 600 mL/min. The method was based on the behavior of total antimony (Sb(Ⅴ+Ⅲ)) and antimony (Ⅲ) under different acidic conditions. Total antimony was determined at 1 mol/L HCI; and antimony (Ⅲ) was determined at pH =4.0～4.5. Under optimized conditions, the detection limit (3σ) for Sb (Ⅴ+Ⅲ) and Sb(Ⅲ) were 0.024 μg/L and 0.0013 μg/L, respectively. For total antimony, the precision for the sample of 0.3 μg/L or 0.03 μg/L was 1.95％ or 1.92％, respectively (n = 9). The linearity was 0～14 μg/L. For antimony (Ⅲ), the precision for the sample of 0.04 μg/L or 0.01 μg/L are 3.8％ or 5.5％, respectively (n = 9). The recoveries for Sb(Ⅴ+Ⅲ) and Sb(Ⅲ) are 93.7％～105％ and 91.1％～104％, respectively. The method can be used directly to the determination of Sb (Ⅴ+Ⅲ) and Sb (Ⅲ) in natural water.