操作:取本品约1克,精密秤定,放於100毫升容量瓶中,用水溶解後再加水至刻度处,测定时取该溶液10毫升,放於玻塞磨口烧瓶中(或碘定量瓶),加入0.1N溴酸钾溶液25毫升及溴化钾0.5克,然後再加入適量浓盐酸(使溶液最後的酸度成2N为止)。密塞,在暗处放置十分钟,时常摇动之,然後再加入0.1N三氧化二砷溶液20毫升,在水浴上加热至60— Operation: Take about 1 g of this product, set it in a 100 ml volumetric flask, dissolve in water and add water to the mark. Take 10 ml of the solution and place in a glass stopper 25 ml of 0.1 N potassium bromate solution and 0.5 g of potassium bromide were added, and then an appropriate amount of concentrated hydrochloric acid was added (to bring the final acidity of the solution to 2N). Mesh, placed in the dark for ten minutes, often shaking it, then add 0.1N arsenic trioxide solution 20 ml, heated in a water bath to 60-