钯与2-(4-安替比林偶氮)-5-氨基苯甲酸的显色反应的研究及其应用

Spectrophotometric study on the colour reaction of Palladium with 2-(4-Antipyrinylazo) -5-aminobenzoic acid and its application

合成了新试剂 2 - (4 -安替比林偶氮 ) - 5 -氨基苯甲酸 (AAAB) ,并研究与钯 (Ⅱ )的选择性光度测定方法 .在Tween 2 0存在下 ,试剂与Pd(Ⅱ )形成 2∶1的红色配合物 ,λmax =480nm ,ε =1.91× 10 4 L·mol-1·cm-1,钯在 0～ 1μg/mL范围内符合比尔定律 ,选择性较好 ,已用于石钯渣和Pd -活性碳催化剂中微量钯的测定 ,无需特别分离 .方法简便、快速。

The synthesis of a new chromogenic reagent 2-(4-antipyrinylazo)-5-aminobenzoic acid(AAAB) is described.A selective spectrophotometry of palladium with AAAB is developed.In the presence of Tween 20,the palladium forms a red complex with AAAB in molar ratio 1:2 and its maximum absorption of is at 480?nm.The molar absorptivity is 1.91×10 4?L·mol -1·cm -1.Beer's law is obeyed over the range of 0～25?μg/25?mL,and shows good selectivity.The method has been applied to the determination of microamounts of palladium in catalysts or slag containing palladium without special seperation.The proposed method is simple,rapid and accurate.