直接碘量法测定粗硒中的硒

摘要

Establish the direct determination of selenium in crude selenium by iodine volume method of analysis method. Thus made the non-ferrous industry standard of the coarse part 3: selenium chemical analysis method on the determination of selenium content of iodine quantity method. Sample using nitric acid, sulfuric acid decomposition, in the 6 mol/L HCL solution of tartaric acid, selenium with hydroxylamine hydrochloride reduction precipitation monomer, filtering and other elements, dissolved in acid, monomer selenium in sulfuric acid medium, using sodium thiosulfate standard solution titration. Near the end to join the potassium iodide, the precipitation reaction with starch as the indicator of iodine, continue to undertake the titration with sodium thiosulfate standard titrate solution to determine the amount of selenium in crude selenium. Methods measuring range was 70.00%~98.00%; Methods relative standard deviation was 0.084%~0.084%. Standard addition recovery rate was 98.8%~100.6%.%建立了直接碘量法测定粗硒中硒的分析方法,采用硝酸、硫酸分解试料,在含有酒石酸的6 moL/L盐酸溶液中,用盐酸羟胺还原析出单体硒,过滤,与其它元素分离,单体硒用酸溶解,在硫酸介质中,用硫代硫酸钠标准溶液进行滴定.临近终点时加入碘化钾,反应析出的碘以淀粉为指示剂,继续用硫代硫酸钠标准滴定溶液进行滴定来测定粗硒中的硒量.方法测定范围70.00%~98.00%,方法相对标准偏差0.084%~0.18%,加标回收率98.8%~100.6% .