分光光度法测定乙醛催化剂中的钯含量

Determination of palladium in the ethanol catalyst by spectrophotometry

拟定了乙醛催化剂中钯的分析方法。用４（２吡啶偶氮）间苯二酚（ＰＡＲ）作显色剂，在ｐＨ＝５６０～９００范围内与钯形成红色配合物，其最大吸收峰位于５０２ｎｍ处，表观摩尔吸光系数为２５２×１０４Ｌ·ｍｏｌ－１·ｃｍ－１。钯浓度在０～２４μｇ／ｍｌ范围内符合比尔定律。配合物的组成比为１∶１，表观稳定常数为６７２×１０５，回收率为９６０％～１０３３％，相对标准偏差（ＲＳＤ）为３７２％。本方法操作简便，用于实际样品中钯的测定，结果较为满意。

A new method for the determination of palladium in the ethanol catalyst has been proposed. The reagent of 4 (2 pyridylazo) resorcin (PAR) was used as chromogenic agent. A red complex was formed with palladium in pH 5.60～9.00. The maxium absorption of the complex lay at 502nm, and the apparent molor absorptivity was 2.52×104 L·mol-1·cm-1. Beer′s law was obeyed for palladium concentration in the range of 0～2.4μg/ml. The composition ratio of the complex was 1∶1, and the apparent stability constant was 6.72×10 5. The recovery was 96.0～103.3%, and the relative standard deviation was 3.72%. This method is simple, and is applicable to determination of palladium of real samples with good results.