钯-二安替比林对溴苯基甲烷-钒体系阻抑动力学光度法测定微量钯  

Inhibitory Kinetic Spectrophotometric Determination of Trace Palladium with Pd DA p BM V Mn System

作　　者：刘家琴[1] 徐其亨[2] 李祖碧[2] 朱利亚[2] 

机构地区：[1]四川省绵阳师专化学系 [2]云南大学化学系

出　　处：《岩矿测试》1999年第1期38-40,共3页Rock and Mineral Analysis

摘　　要：在Ｈ３ＰＯ４介质中，微量Ｐｄ（Ⅱ）能阻抑二安替比林对溴苯基甲烷（ＤＡｐＢＭ）与Ｖ（Ⅴ）的显色反应，阻抑程度与Ｐｄ（Ⅱ）量呈线性相关。据此建立了测定微量Ｐｄ（Ⅱ）的新方法。方法检测限为５６．０μｇ／Ｌ，测定范围为０．０～４８０．０μｇ／ＬＰｄ（Ⅱ）。阻抑反应的表观活化能为８６．７２ｋＪ／ｍｏｌ，表观速率常数为５．５７×１０－４／ｓ，反应终止后至少稳定２４ｈ。试样的加标回收率为９１．７％～１０１％（ｎ＝４）。该法用于ｗ（Ｐｄ）在１０－３水平的冶金产品和催化剂中钯的测定，结果与原子吸收法测定结果相符，ＲＳＤ（ｎ＝６）在２．８％～３．３％。A kinetic spectrophotometric method based on the inhibitory effect of trace palladium on the Mn(Ⅱ) catalyzed reaction between DA p BM and V(Ⅴ) in phosphoric acid medium is proposed for the determination of trace palladium. The inhibitory degree is proportional to the amount of palladium. Under the selected experimental conditions, the linear range of the determination is 0.0～480.0 μg/L with detection limit of 56.0 μg/L for Pd(Ⅱ). The apparent activation energy of the inhibitory reaction is 86.72 kJ/mol and the apparent reaction rate constant is 5.57×10 -4 /s. The system is stable in at least 24 h. The recovery of standard addition is 91.7 %～101%( n =4). The method has been applied to the determination of trace palladium in metallurgical products and catalyst samples. The results are in good agreement with those provided by AAS with precision of 2.8 %～3.3% RSD ( n =6).

关 键 词：阻抑反应 动力学光度法 钯 溴苯基甲烷 钒体系 

分 类 号：O614.823[理学—无机化学]