论文部分内容阅读
近年来国内许多单位采用二乙基二硫代氨基甲酸银(简称Ag-DDC)比色法测定微量砷。我厂也曾采用此法,但该法需要特殊的砷化氢发生装置,砷转化为有毒的砷化氢气体,分析一个液体样约需1.5小时,试剂费用高,满足不了生产的需要。本法根据AsO_3~3+I_2+H_2O(?)AsO_4~3+2I+2H~+这一反应,研究了严格控制pH值及消除钼、铁等元素的干扰,探索了含低价硫、钼及有机物高的液体试样中砷的测定方法,方法精密度优于6％,回收率92—106％。主要试剂 50％碘化钾溶液(配制时加2—3粒
In recent years, many domestic units using trace silver dithiocarbamate (Ag-DDC) colorimetric determination of trace arsenic. Our factory has also adopted this method, but the law requires a special arsine generator, arsenic into toxic arsine gas, analysis of a liquid sample takes about 1.5 hours, reagent costs are high, can not meet the production needs. According to the reaction of AsO_3 ~ + I_2 + H_2O (?) AsO_4 ~ 3 + 2I + 2H ~ +, this paper studied the strict control of pH value and elimination of the interference of molybdenum, iron and other elements, And high liquid organic sample of arsenic determination method, the precision of better than 6%, the recovery rate of 92-106%. The main reagent 50% potassium iodide solution (preparation of 2-3 tablets