在磷酸介质和加热条件下，痕量铑(Ⅲ)能灵敏地催化高碘酸钾氧化二安替比林对二甲氨基苯基甲烷(DAMAM)的显色反应。研究了该催化反应的最佳实验条件及动力学参数，建立了一种动力学光度法测定痕量铑的新方法。方法的线性范围为0～84μg/L；检出限为6.20×10-7g/L。催化反应的表观活化能为89.03kJ/mol，表观速率常数为2.51×10-4/s，反应终止后至少稳定6 h。本法已用于某些催化剂中铑的测定，其相对标准偏差为2.7％～3.2％；标准加入回收率为98.2％～103.2％。%A kinetic method for the detemination of trace rhodium based on the catalytic effect of Rh on the oxidative color reaction of diantipyry1-(p-dimethylamino)-phenylmethane (DAMAM) with potassium periodate in the H3PO4 medium and ot wateer bath was estabished. The optimum condition and kinetic parameters of this reaction were studied in detail. The linear range of the determination was 0～80μg/L, and the detection limit was 6.20×10-7g/L. The apparent activation energy og catalytic reaction was found to be 89.03kJ/mol, rate constant was 2.51×10-4/s. The system wasstable at least 6h. The method has been applid to determine trace rhodium in some catalyst samples with the relative standard deviation of 2.7%～3.2%(n=6) and recovery of 98.2%～103.2% (n=5).
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