砷钼蓝杂多酸—凝胶相吸光光度法测定废水中的砷

Determination of trace amounts of arsenic by sephadex g-25-phase dual wevelength spectrophotometric method with molybdoarsenic blue

本文采用砷化氢挥发法分离污水中的砷 ,然后直接测量富集在凝胶相上的砷钼蓝杂多酸的吸光度以测定种。砷在 0～ 7μg/ 5 0ml范围内符合比尔定律。本方法灵敏 ,选择性好 。

Arsenic is seperated from waste water by the volatilization of AsH 3 and AsH 3 is absorpted by iodine-potassium iodide solution.The blue species of molybdoarsenic is absorbed by Sephadex G-25 gel from the solution.The Gel-phase background is eliminated by dual wave length equal absorption point method(λ1=820nm λ2=600nm).This method is more sensitive,lessinterference more precise and easily to operate.The analytical result is satisfactory.Beer'law is obeyed in the range of 7 per 50ml.The relative errors are less than 10%.Ion do not interfere under given conditions.