新银盐光度法测定石脑油中微量砷

石脑油中的微量砷用硫酸——过氧化氢萃取、消解 ,用硼氢化钾发生砷化氢 ,经净化除去其中的杂质 ,被硝酸银——聚乙烯醇——乙醇溶液吸收显色 ,在 41 0nm测定吸光度 .考察了砷化氢的吸收显色条件 ;讨论了共存离子的影响及消除干扰的方法 .油品分析结果与二乙基二硫代氨基甲酸银 ( Ag- DDC)光度法测得值吻合得很好 .加标回收率为 94.9%～ 1 0 4 .1 % .方法简便、灵敏、快速 ,试剂毒性小 ,适用范围广 .

DETERMINATION OF MICROAMOUNT ARSENIC IN NAPHTHA BY A NEW SILVER SALT SPECTROPHOTOMETRY

A new method of determining microamount arsenic in naphtha was proposed. The method was based on extraction of the arsenic into an aqueous solution of H 2SO 4 and H 2O 2, which thereafter was digested. Then the arsenic was reduced into arsine by KBH 4. Arsine was purified by removing the impurity from it, and absorbed by solution of nitric acid silver nitrate polyviylol ethanol. The color was photometrically measured at 410 nm. Absorbed and coloured conditions of Arsine were investigated. Influence of coexistence ion on this method was discussed. The analytital results of oil products were identified with Ag DDC spectrophotometry. The recovery ratio is 94%～104%. The advantages are simple operation, less time consuming, high sensitivity, low toxicity of reagents and wide range of application.