金(Ⅲ)与 3,3’,5,5’-四甲基联苯胺显色反应的研究和应用于微量金的测定

Colour Reaction of Gold (Ⅲ) With 3,3',5,5'-Tetramethylbenzidine and Its Application for the Determination of Trace Gold

本文研究了An(Ⅲ)与 3,3′,5.5′-四甲基联苯胺(TMB)的显色反应,在0.02mol/L盐酸介质中,TMB于波长450nm处有最大吸收,摩尔吸光系数为1.03×10~5L·mol^(-1).cm^(-1).25ml溶液中0～40μg金(Ⅲ)符合比尔定律,本方法已用于粗铜中微量金的测定.

The colour reaction of Au (III) with 3,3' 5,5'-tetramethylbenzidine in 0. 02 mol/ L hydrochloric acid solution was studied. The molar absorptivity of this system at 450 nm is 1.03 X 105 L mol-1 cm-1. Beer's law is obeyed in the range of 0~40g/25 ml for Au (III). This method has been applied to the determination of trace amounts of Au in coarse copper.