示波指示技术在动力学分析中的应用(Ⅲ)——示波双安培催化动力学法测定铜和碘

Application of Oscillo-indicating Technique to Kinetic Analysis ( Ⅲ)——Determination of Copper and Iodine by Catalytic Method with Oscillo-biamperometry

双安培法是一种灵敏度很高的分析方法,近年来已有许多应用.作者曾将双安培示波法用于确定氧化还原滴定的终点.本文将双安培示波技术用于催化动力学分析获得成功.在动力学分析中,加入不同浓度的催化剂,用本法测出指示组分达到一定浓度的时间,即可测得催化剂的浓度.因为示波器很稳定,测定电流的灵敏度很高,且不受试液的颜色或沉淀的影响,所得结果的重现性好,线性范围较宽,所以此法比光度法优越.

This paper reports the application of oscillo-indicating technique to kinetic analysis. Cu ( Ⅱ ) and I- are determined by oxidation of Na2S2O3 with Fe( Ⅲ ), which is catalyzed by Cu( Ⅱ ) and by oxidation of As( Ⅲ ) with Ce( Ⅳ ) , which is catalyzed by I- , respectively. The detective limit reaches 2× 10-7 mol/L for Cu( Ⅱ ) and 2× 10-8 mol/L for I-. This method shows advantages of sensitivity, convenience and economy.