【摘要】 本文研究了４－（５－溴－２－吡啶偶氮）－１，３－二氨基苯（简称５－Ｂｒ－ＰＡＤＡＢ）与Ｐｄ（Ⅱ）的显色反应条件，确定在ＨＡｃ条件ＴＰｄ（Ⅱ）与５－Ｂｒ－ＰＡＤＡＢ生成紫红色络合物，在０．８ｍｏｌ／Ｌ的ＨＣｌ介质中进行光度测定，以提高方法的选择性。实验结果表明，络合物的络合比为１：１，表现摩尔吸光系数ε＝５．２０×１０￣４，条件稳定系数Ｋ＿稳＝１．６×１０￣７，钯离子浓度在４．２７×１０￣（－８）～１．５４×１０￣（－５）ｍｏｌ／Ｌ时服从比尔定律。应用所拟方法测定冶金生产过程中间产品中微量钯，获得满意的结果。更多还原

【Abstract】 In this paper, the spectrophotometric determination of Pd(Ⅱ)with 4-(5-Bromo- 2- Pyridyl-azo)-1,3-diamino benzene(5-Br-PADAB)was studied. The method is based on the reaction of Pd(Ⅱ)with 5-Br-PADAB to form a red complex in a medium of HAc and is determined in amedium of 0.80mol/LHCl. Maximum absorption of the complex is at 564nm. The apparent molar absorptivity is 5.20 ×10￣4L·mol￣(-1)· cm￣(-1)。Beer’s law isobeyed within the range of 4.27×10￣(-8)～1.54 ×10￣(-5)mol/L·The complex is stablein 24 hrs. The composition of complex has been found to be 1 : 1.Themethod is of better sensitivity and selectivity and has been used to determinemicroamounts of Pd in ores with satisfactory results.更多还原