无富集进样原子荧光光谱法测定地表水中的痕量汞

通过增大样品进样量的方式,样品进样量是标准进样量的10-100倍,降低了汞的检出限,从而达到了无富集直接进样测定地表水中痕量汞.其检出限为0.008μg/L;浓度为0.05μg/L和0.10μg/L左右的有证标准物质测定均值分别为0.0483μg/L和0.1016μg/L,加标回收率为92.3％和95.2％.灵敏度高,精密度好,能达到准确定量Ⅰ类和Ⅱ类地表水汞(0.05μg/L以下)的要求.对汉江湖北段水样进行测定,在较洁净的地表水分析中,氧化还原处理后与酸化水样测定结果差异不大,处理后水样结果略微增大.建议对较洁净的地表水样品将氧化还原预处理步骤省略掉,直接进样.

Determination of Trace Mercury in Surface Water by AFS with No Preconcentration Sampling

The increasement of sampling volume was used to reduce the detection limit of mercury,which was 10—100 times of the standard sampling volume.The trace mercury in the surface water was determined by no preconcentration sampling.The detection limit was 0.008μg/L,and the average determined values of certificated standard samples,the concentration of which were respectively 0.05μg·L^-1,0.10μg·L^-1 and 0.0483μg·L^-1,0.1016μg·L^-1,respectively.The additional standard recoveries were 92.3%and 95.2%.The results had high sensitivity and good precision,and can be meet the requirement of accurate quantitative determination of mercury(its concentration was less than 0.05μg·L^-1) in the NoⅠand NoⅡspecies surface water.The determine data was a little increase compared oxidoreduction sample to acidulated sample in the determined clean surface water,that was the results of samples from the Han river in Hubei province. The oxidoreduction pretreatment step was suggested to omit,and the sample can be directly injected.