主次波长-Ag^+-PADA分光光度法测定痕量银

DETERMINATION OF TRACE SILVER BY PRIMARY-SECONDARY WAVELENGTHES SPECTOPHOTOMETRY IN Ag^+-PADA SOLUTION

在碱性溶液中,Ag^+能催化PADA—苯酚反应,生成兰色化合物.本文在该显色反应基础上根据稳定悬浮体光学吸收行为研究痕量银(Ag)的主次双波长光度测定新方法,建立了稳定的计算模型.方法简单、快速、检出限0.008μ/ml,精密度较高,加标回收率94—105%.适合于清洁水质分析.

In basic solution Ag^+ can accelerate the reaction of PADA and phenol to form a blue compound. In this paper the optical absorption behaviour of such a stable liquid suspension as the ground of the analytical method for trace silver by primary-secondary wavelengthes spectrophotometry is analysed and a calculation model for Ag^+ is establisled which is numerically stable and less sensitive to interference. By analysis of samples of underground water and polluted water the detection limit of silver is deternmined to be 0.008 μg/ml, the precision ≤3.3% and the recovery 94-105%. The method is proved to be suitable for detemination of Ag^+ in clean water and some kinds of polluted water.