本文在卑磷酸盐还原测定砷的方法中,引入聚乙烯醇作分散剂,使砷的工作曲线线性范围扩大,在0—0.30毫克砷/50毫升内线性良好;显色液至少可稳定3小时。方法应用于金属锑中砷的测定,获得满意结果。其分析步骤基本同原法,不同之处是将试样经盐酸-过氧化氢(1+1)分解后,加入卑磷酸钙溶液之前,加入10毫升0.2%(V/V)聚乙烯醇的盐 In the method of determination of arsenic by reduction of hibite, polyvinyl alcohol was used as dispersant to make the linear range of arsenic working curve broaden, and the linearity was good in 0-0.30 mg arsenic / 50 ml; the color developing liquid could be stable for at least 3 hours . The method was applied to the determination of arsenic in metallic antimony and satisfactory results were obtained. The analytical procedure is basically the same as the original method except that the sample is decomposed with hydrochloric acid-hydrogen peroxide (1 + 1) and then added with 10 ml of 0.2% (v / v) polyvinyl alcohol salt