共沉淀富集-石墨炉原子吸收光谱法测定水中砷

Determination of Arsenic in Water by Graphite Furnance-atomic Absorption Spectrophotometry

研究了用氯氧化锆共沉淀浓缩水中微量砷 ,用 1+ 1硝酸溶解沉淀 ,在灰化温度 3 0 0℃ ,原子化温度2 2 0 0℃条件下 ,采用石墨炉原子吸收光谱法直接测定水中砷 ,同时对共沉淀时间 ,沉淀剂的用量及其它共存离子的影响等最佳测试条件作了试验。结果表明 ,砷浓度在 0～ 3 0 μg/L 范围内符合比尔定律 ,方法的回收率为90 .0 %～ 97.5 % ,相对标准偏差为 3 .9%～ 5 .7% ,检出限为 0 .

In this assay,the trace arsenic in water was precipitated and preconcentrated by zirconium hydroxide,then the precipitate was dissolved in nitric acid(1+1) In the end,the content of arsenic was determined by graphite farnance atomic absorption spectrophotometry at ashing temperature of 300 ℃ and atomization temperature of 2 200 ℃ The best conditions for determination,such as coprecipitation period and the amount of precipitant,and the disturbance of other coexisting ions were also explored The results showed that:this assay obeyed Beer′s Law in the range of arsenic concentration from 0~30 μg/L The recovery rate,relative standard deviation and detection limit was 90 0%~97 5%,3 9%~5 7% and 0 1 μg/L respectively