赶酸器浓缩-湿法消解-原子荧光光谱法检测生活饮用水中痕量硒

Determination of track selenium in drinking water by concentrationprereduction-hydride--generation atomic fluorescence spectrometry

目的建立了赶酸器浓缩-湿法消解-原子荧光法测定生活饮用水中硒的分析方法。方法水样于赶酸器上220℃加热浓缩,冷却后加入2.0ml HNO3+H2O2(1+1)混合溶液,220℃加热消解,冷却后加入6 mol/L盐酸2.5 m L,140℃继续加热至微沸,持续约5 min,以2.00%盐酸作为载流液,以15 g/L硼氢化钾溶液(含0.20%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=76.34c-7.74,r=0.999 9。该方法的检出限为0.033μg/L,平均回收率为96.5%~100.0%,RSD均小于2.0%。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痕量硒的测定。

Objective To develop a method for the determination of trace selenium （Se） in drinking water by hydride generation atomic fluorescence spectrometry with concentration and wet digestion. Methods Water samples were condensed at 220℃ on a programmable pretreater, after cooling down, 2.0 ml HNO3＋H2O2 （1 ＋1） mixed solution was added. Samples were digested at 220 ℃ on a programmable pretreater, after cooling down, 2.5ml of 6mol/L HC1 was added. Samples were then heated to 140℃ and kept simmering for 5 rain. Se was determined via hydride generation atomic fluorescence spectrometry using 2.0 % HCI as carrier fluid and 15g/L KBH,-0.20 % KOH as reductant. Results In the linear range of 1.0-20 μg/L, the regression equation of standard curve was If=76.34c-7.74 for Se, and showed good linear relationship,r=0.999 9.Tbe detection limit of detection was 0.033 μg/L,the average recovery rates were 96.5 %-100.0 %, and the relative standard deviations （P, SDs） of the method for Se were below 2.0 %. Condusion The proposed method is simple, safe,rapid,accurate,precise, and it is applicable to the determination of Se in drinking water.