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碘量法测定铜是经典方法。近来报导有加入聚乙烯吡咯烷酮(简写PVP),可使碘化亚铜的沉淀不析出。我们按文献作了试验,介绍如下。称样0.5克置于150毫升锥形瓶中,加HCl(1+5)10毫升,分次加入H_2O_2(30%)约3毫升,微温溶解后,加热煮沸以除剩余的过氧化氢,冷却,稀至100毫升量瓶中,吸取20毫升于250毫升锥形瓶中,加水100毫升,加NH_4HF_2约0.3克溶解,加PVP(10%)5毫升混好后,加KI1.5克混合溶解,即用Na_2S_2O_3
Iodometric determination of copper is the classic method. It has recently been reported that polyvinylpyrrolidone (abbreviated PVP) is added so that precipitation of cuprous iodide is not precipitated. We made a trial according to the literature, introduced below. Weigh 0.5g in a 150ml Erlenmeyer flask and add 10ml of HCl (1 + 5). Add about 3ml H 2 O 2 (30%) in several portions, dissolve in warm water and boil to remove the remaining hydrogen peroxide. Cool , Dilute to 100 ml volumetric flask, draw 20 ml in 250 ml Erlenmeyer flask, add water 100 ml, add about 0.3 g NH_4HF_2 dissolved, add PVP (10%) 5 ml mixed, add KI 1.5 g mixed dissolved , That is, with Na_2S_2O_3