石墨炉原子吸收法测定环境水样中铊

Determination of Thallium in Environmental Water Samples by GF-AAS

对石墨炉原子吸收法测定水中铊的分析条件进行优化,并比较不同前处理方法对测定结果的影响。结果表明仪器的最佳分析条件为:灰化温度和原子化温度分别为700和1 600℃,进样量为40μL,基体改进剂为0.5%的钯与硝酸镁。直接进样、MIBK萃取法和铁沉淀富集3种前处理方法对应的检出限分别为0.76,0.07和0.02μg/L;分别测定5,0.5和0.1μg/L含铊水样,其相对标准偏差分别为4.2%,6.1%和8.4%,加标回收率分别为92%,91%和88%,即3种样品前处理方式下,石墨炉原子吸收法对环境水样中铊均具有较好的测定效果。直接进样法适用于铊浓度较高的水样,MIBK萃取法和铁沉淀法则适用于较清洁水样。

GF-AAS conditions for determining thallium in environmental water samples were optimized and the effect of different pretreatment methods on the determination was studied. The optimized analysis conditions are as follows: ashing temperature 700 ℃;atomization temperature 1 600 ℃; sample load 40 μL; matrix modifier 0. 5% Pd and Mg( NO3)2. The detection limits of the three pretreatment methods including direct injection,MIBK extraction,and ferrum precipitation enrichment were 0. 76,0. 07,and0. 02 μg / L. The relative standard deviations were 4. 2%,6. 1%,and 8. 4% for 5,0. 5,and 0. 1 μg / L of water samples containing thallium,respectively. The recoveries of the three pretreatment methods were 92%,91%,and 88%. The method could satisfy the requirement for the determination of thallium in different environmental water samples using all of three pretreatments.