高精密库仑滴定法测定三氧化二砷的纯度  

Assay of Arsenic Trioxide by High-precision Coulometric Titrimetry

作　　者：吴冰[1] 巢静波[1] 

机构地区：[1]中国计量科学研究院化学计量与分析科学研究所,北京100013

出　　处：《现代科学仪器》2009年第3期69-72,共4页Modern Scientific Instruments

摘　　要：高精密库仑滴定法是国际上公认的基准测量方法,该方法根据法拉第电解定律,通过质量、电阻、电动势、时间等基本物理量及法拉第常数来进行三氧化二砷纯度的测定,直接溯源到国际SI单位,不需要用标准物质进行比对。样品以氢氧化钾溶液溶解,通过电解产生碘与亚砷酸盐定量反应,以死停终点法确定终点。该方法具有很高的测量精度和准确性。The constant current coulometry as a primary method is recognized in international. Based on Faraday＇s law of electrolysis, it has been successfully used to determine purity of arsenic trioxide. The measuring results depend directly on the reliability of measuring physical quantities （mass, resister, voltage, time） and fundamental constants expressed in SI units, and do not need a reference material for comparison. The sample dissolved in potassium hydroxide solution. The titration reagent 12 reacted quantificationally with arsenide. The end-point is determined by dead-stop end point. The method is provided with high precise and accurate.

关 键 词：三氧化二砷 高纯物质 高精密库仑滴定法 氧化还原 

分 类 号：TQ126.4[化学工程—无机化工]