[Pretreatment of supported Wacker catalysts and the determination of palladium and copper].

The supported Wacker catalysts were pretreated with two different methods. Then copper and palladium were determined by inductively coupled plasma atomic emission spectrometry(ICP-AES). The results showed that the best pretreatment method is burning-acid dissolving. With this method, the detection limits of Pd and Cu were 3.127 and 2.548 ng x mL(-1), the recoveries of standard addition of Pd and Cu were 96.26% and 94.82%, and the relative standard deviations (n=11) of Pd and Cu were less than 1.237% and 1.354%, respectively. The method is efficient, accurate, and easy to operate. Pd and Cu in supported Wacker catalysts, which were sampled before calcination, after calcination and after reaction, were determined by this method, and the contents were compared with calculated values. The percentages were larger than 96.4% and 96.6% respectively. It is considered that the active components did not decrease in preparation and reaction.