生活饮用水中微量硒的浓缩-预还原-原子荧光光谱测定法

Determination of trace selenium in drinking water by concentration-prereduction-hydride-generation atomic fluorescence spectrometry

目的建立生活饮用水中微量硒的浓缩-预还原-原子荧光光谱测定法。方法水样于智能样品处理器上220℃加热消解浓缩,冷却后加入6 mol/L盐酸2.5 ml,140℃继续加热至微沸,持续约5 min,以2%盐酸作为载流液,以15 g/L硼氢化钾溶液(含0.2%氢氧化钾)为还原剂,采用原子荧光法测定水中硒浓度。结果硒在1.0~20μg/L的线性范围内线性关系良好,所得回归方程为If=71.88×c+1.575,r=0.999 9。该方法的检出限为0.036μg/L,平均回收率为96.5%~101.0%,RSD均小于3.0%。结论该方法操作简便,安全,快速,精密度、准确度均较高,适用于生活饮用水中微量硒的测定。

Objective To develop a method for the determination of trace selenium（Se） in drinking water by hydride generation atomic fluorescence spectrometry with concentration and prereduction. Methods The water samples were digested and condensed at 220 ℃ on a programmable pretreater, after cooling down, 2.5 ml of 6 mol/L HCl was added. The samples were then heated to 140 ℃ and kept simmering for 5 min. Se was determined via hydride generation atomic fluorescence spectrometry using 2% HCl as the carrier fluid and 15 g/L KBH_4-0.2% KOH as reductant. Results In the linear range of 1.0-20 μg/L, the regression equation of standard curve was If=71.88c＋1.575 for Se, with a good linear relationship,r=0.999 9. The limit of detection was 0.036 μg/L,the average recovery rates were 96.5%-101.0% and RSDs of the method for Se were below3.0%. Conclusion The developed method is simple,safe,rapid,accurate,precise and is applicable to the determination of Se in drinking water.