分光光度研究3,5-二溴—PADAT与钯的显色反应

分光光度研究3,5-二溴—PADAT与钯的显色反应 SPECTROPHOTOMETRIC STUDY OF THE COLOUR REACTION OF PALLADIUM（Ⅱ）WITH 3, 5—diBr—PADAT 徐勉懿 first-author 潘祖亭 谢能詠 宋宇 < 正 > 5—[（3,5—二溴—2—吡啶）偶氮]—2,4-二氨基甲苯（简称3,5—二溴—PADAT）是测定微量钴的灵敏试剂[1] 。近年来曾报导用5—Cl—PADAB[2,3]和3,5—二氯—PADAT光度法测定钯[4] ,然而3,5-二溴—PADAT与钯的显色反应尚未见详细报导。本文研究了3,5—二溴—PADAT与钯的显色反应条件,测定了络合物组成。结果表明,在含有40%乙醇的酸性溶液中,3,5—二溴—PADAT与钯形成紫包络合物,其最大吸收波长在590nm处。络合物组成为3,5—二溴—PADAT:Pd 2+ =1:1。表观摩尔吸光系数为1.06×10 5 。其灵敏度高于前述2—吡啶偶氮类试剂,许多常见离子都不干扰测定。将拟定的方法应用于试样分析,操作简便快速。我们曾用本法测定含钯催化剂中钯的含量,获得了较满意的结果。 The conditions for the colour reaction of 5--（3,5—Dibromo—2-Pyridyl- azo） —2,4—diamino toluene （3,5—diBr—PADAT） with Palladium（Ⅱ）were investigated. Aviolet complex（1:1） of Palladium（Ⅱ）with the cited reagent was formed in the range of pH 2 to 2N HC1 solutions by heating the reactants at 70℃—80℃ for 15 minutes The complex has maximum absorption at 590 nm with a molar absorption coefficient of 1.06×10 5 in 40% ethanol. Becr′s law is obeyed for palladium in concentration of 0 to 20 ug/25ml. This method has been applied to the direct determination of palladium content in Pd-containing Cataysts without interfercnce by many other commonions 1983-03-01 2021-04-01 3