本文进一步探讨了AgDDC测定微量砷的最佳条件,指出还原AS~(5+)以在低酸度溶液和较高温度下进行所得结果较好。在本文所改进的条件下,对相同砷量测量的吸光度值均比前人所沿用的方法有所提高,从而提高了方法的准确性。用本文方法测定飘尘、污水、污泥,以及矿石中的砷,结果均很满意,相对误差一般小于3％。 In this paper, the optimum conditions for the determination of trace arsenic by AgDDC were further discussed. It is pointed out that the reduction of AS 5+ is better in low acidity solution and at higher temperature. Under the conditions of this article, the absorbance values ​​of the same arsenic measured are higher than the previous methods, which improves the accuracy of the method. The method for the determination of arsenic in fly ash, sewage, sludge, and ores was satisfactory and the relative error was generally less than 3%.