用DL-Methionine为释放剂选择性螯合滴定法测定钯含量。加入过量EDTA螫合Pd~(2+)和其他金属离子,剩余EDTA在pH5～6时,以Zn~(2+)标准溶液、XO-CPB为指示剂,进行滴定。然后加入DL-Methionine分解Pd-EDTA蝥合物,释放析出的EDTA(与Pd~(2+)等摩尔),再用Zn~(2+)标准溶液进行滴定,终点颜色变化敏锐、清晰。实验表明,阳阴离子都不干扰,选择性相当高,已成功地用于测定触媒、合金和复杂络合物中的钯,结果十分满意。 The palladium content was determined by selective chelation titration with DL-Methionine as a release agent. Addition of excessive amounts of EDTA and Pd 2+ and other metal ions, and the remaining EDTA at pH 5-6, titrate with Zn 2+ standard solution and XO-CPB as indicator. Then, DL-Methionine was used to decompose the Pd-EDTA complex to release the precipitated EDTA (equimolar to Pd 2+), and titrated with Zn 2+ standard solution. The endpoint color change was sharp and clear. Experiments show that the cation does not interfere with the selectivity is quite high, has been successfully used in the determination of catalysts, alloys and complex complexes of palladium, the results are very satisfied.