2-(5-溴-2-吡啶偶氮)-5-二甲氨基苯胺与铂显色反应的研究及应用

• 作 者: 王贵方 周艳梅 张光
• 机 构: 陕西师范大学化学系
• 出 处: 岩矿测试
• 发表日期: 1998年02期
• 关键词: 铂 2-(5-溴-2-吡啶偶氮)-5-二甲氨基苯胺 分光光度法

研究了显色剂２（５溴２吡啶偶氮）５二甲氨基苯胺（５ＢｒＰＡＤＭＡ）与Ｐｔ（Ⅱ）的显色反应。结果表明，在乙醇存在下，１０～３２ｍｏｌ／ＬＨ３ＰＯ４介质中，试剂与Ｐｔ（Ⅱ）１５ｍｉｎ即形成稳定的紫蓝色配合物，并至少稳定２４ｈ。该配合物的最大吸收波长位于６２８ｎｍ处，表观摩尔吸光系数为８７３×１０４Ｌ·ｍｏｌ－１·ｃｍ－１，其组成为ｎＰｔ（Ⅱ）∶ｎ５ＢｒＰＡＤＭＡ＝１∶１，Ｐｔ（Ⅱ）的质量浓度在０～１０ｍｇ／Ｌ符合比尔定律。所拟方法用于二次合金管理样及催化剂中铂的直接测定，结果与推荐值相符，精密度好，ＲＳＤ＜０．５％（ｎ＝６）。

The color reaction of 2  (5bromo  2pyridine azo)  5dimethylaminoaniline (5BrPADMA) with Pt (Ⅱ) was studied. The results showed that in the presence of ethanol, 10 ~ 32mol / LH3PO4 medium, the reagent and Pt (Ⅱ) 15min to form a stable purple blue complex, and at least stable 24h. The maximum absorption wavelength of the complex is located at 628nm, the apparent molar absorptivity is 873 × 104L · mol-1 · cm-1, and its composition is nPt (Ⅱ): n5BrPADMA = 1: 1, Pt (Ⅱ) concentration of 0 ~ 1  0mg / L Beer’s law. The proposed method was applied to the direct determination of platinum in the secondary alloy management samples and catalysts. The results were consistent with the recommended values ​​and the precision was good with RSD <0.5% (n = 6).