氢化物发生-原子荧光光谱法对环境水样中砷(Ⅲ)与砷(Ⅴ)的直接测定

Direct Determination of As(Ⅲ) and As(Ⅴ) in Environmental Water Sample by Hydride Generation-Atomic Fluorescence Spectrometry

建立了氢化物发生-原子荧光光谱直接测定水样中As（Ⅲ）和As（Ⅴ）的方法,操作简便,实用性强。考察了HCl和KBH4浓度对As（Ⅲ）和As（Ⅴ）测定灵敏度的影响以及共存元素的干扰情况。通过测定经还原剂还原前后水样中砷的荧光强度,计算出As（Ⅲ）和As（Ⅴ）的含量。方法检出限为As（Ⅲ）0.085μg·L^-1As（Ⅴ）0.108μg·L^-1As（Ⅲ）和As（Ⅴ）的加标回收率分别为96%～104%和97%～104%,RSD均小于6%。该法用于实际水样的测定,结果较为满意。

A simple, rapid and useful method for the determination of As （ Ⅲ ） and As （ Ⅴ ） in environmental water sample has been established by hydride generation - atomic fluorescence spectrome- try. Effects of HCl and KBH4 concentrations on sensitivities of As （ Ⅲ ） and As （ Ⅴ ） were investigated, and interferences of co-existed elements were studied. Under the optimal conditions, the concentrations of As（ Ⅲ ） and As（ Ⅴ） were detected by measuring fluorescence intensities of arsenic in water before and after reduction with reductant. The calibration curves showed a good linearity in the range of 0 -50 μg·L^-1 for As（ Ⅲ ） and As（ Ⅴ ）. The detection limits of As（ Ⅲ ） and As（Ⅴ） were 0. 085 μg · L^-1 and 0. 108 μg·L^-1 , respectively, and the spiked recoveries from water matrix were range of 96% - 104% for As（ Ⅲ） and 97% - 104% for As（ Ⅴ ） with RSDs of less than 6%. The method was applied for determination of As（ Ⅲ） and As（ Ⅴ ） concentration in real water samples with satisfactory results.