【摘要】 ｐＨ９．７～１０．６的Ｎａ２ＣＯ３－ＮａＨＣＯ３缓冲介质中，有乳化剂ＯＰ存在８０℃水浴加热５ｍｉｎ后，Ｐｄ（Ⅱ）与邻菲罗啉和２，６－二溴－４－羧基苯基重氮氨基偶氮苯（ＤＢＣＤＡＡ）形成组成比为１∶１∶２的红色三元配合物，其最大吸收波长和对比度分别为５２４ｎｍ和１２６ｎｍ，表观摩尔吸光系数为７．１６×１０４Ｌ·ｍｏｌ－１·ｃｍ－１，线性范围为０～０．６０μｇ／ｍｌ，配合物至少稳定２４ｈ。用交换树脂分离，方法用于测定二次合金中微量Ｐｄ，相对误差为－５．９％，相对标准偏差为３．８％（ｎ＝６）。更多还原

【Abstract】 A new spectrophotometric method for determination of micro amounts of Pd (Ⅱ) has been proposed with 2,6-dibromo-4-carboxybenzenediazoaminoazobenzene (DBCDAA) and 1,10-phenanthroline (phen). In Na 2CO 3-NaHCO 3 buffer medium of pH 9 7～10 6 and in the presence of p-octylpolyethyleneglycol phenyl-ether (OP), Pd(Ⅱ) reacts with phen and DBCDAA to develop a stable, soluble complex. The complex has a maximum absorption at 524 nm, with contrast of 126 nm and an apparent molar absorptivity of 7 16×10 4 L·mol -1 ·cm -1 . The development is complete after heating in 80℃ water bath for 5 min, and the color is stable for at least 24 h. The molar ratio of Pd(Ⅱ) to phen and DBCDAA in the complex is estimated to be 1∶1∶2. Beer’s law is obeyed up to 0 60 μg/ml of Pd. Most of the interfering common metal ions are separable by ion-exchange chromatography. The method has been applied to the analysis of a secondary alloy with relative error of-5 9% and RSD of 3 8% (n=6).更多还原