在丙酮介质中2－（4，5－二甲基－2－噻唑偶氮）－5－二甲氨基苯甲酸光度法测定微量钯的研究

Study of Spectrophotometric Determination of Trace Palladium with 2-(4, 5-Dimethyl-2-Thiazolylazo)-5-Dimethylaminobenzoic Acid in the Presence of Acetone

本文研究了２－（４，５－二甲基－２－噻唑偶氮）－５－二甲氨基苯甲酸（简称ＤＭＴＡＭＢ）与钯的显色反应．实验结果表明．在ｐＨ３．６～４．８范围内．在２８％丙酮介质中，ＤＭＴＡＭＢ与钯可形成稳定的蓝绿色络合物，络合比为Ｐｄ（２－）：ＤＭＴＡＭＢ＝１：１．络合物表现摩尔吸光系数ε（７０４）＝７．２×１０４Ｌ·ｍｏｌ１·ｃｍ１，钯浓度在０～３０μｇ／２５ｍｌ范围内遵守比耳定律．本法不经预分离用于钯精矿样、含钯分子筛及含钯电镀液样品的测定，结果满意．

A sensitive photometric method for the determination of Pd (Ⅱ) with 2-(4, 5-dimethyl-2-thiazolylazo)-5-dimethylaminobenzoic acid (DMTAMB ) has been studied. The experimental results indicate that in the presence of acetone at pH3.6￣4.8,Pd (Ⅱ) reacts with DMTAMB to form a stable blue-green 1: 1 complex with apparent molar absoptivity of 7.2×104 L·mol 1·cm 1 at 704 nm. Beer's law is obeyed in the range of 0￣30μg/25ml for Pd(Ⅱ). This method has been applied to the determination of Pd(Ⅱ) in samples containing Pd with satisfactory results.