4,5-二溴邻硝基苯基荧光酮分光光度法测定催化剂中铂

Spectrophotometric determination of platinum(Ⅳ) in catalyst with 4,5-dibromo-2-nitro-phenyfluorone

研究了4,5-二溴邻硝基苯基荧光酮（DBON-PF）与Pt（Ⅳ）的显色反应,并建立了分光光度法测定铂的方法。在复配型微乳液CPB/OP存在下和在pH 3.6的HAc-NaAc缓冲溶液中,Pt（Ⅳ）与DBON-PF形成1∶2的淡红色络合物,其最大吸收峰位于476 nm波长处,表观摩尔吸光系数为ε=1.88×105Lmol^-1·cm^-1。在10 mL显色液中,Pt（Ⅳ）量在0-14μg范围内符合比尔定律,方法检出限为1.06×10-6g/L。本法用于铂催化剂中铂的分析,回收率为97.6%-105.0%,相对标准偏差为1.1%-2.1%,测定结果与原子吸收光谱法相吻合。

The chromogenic reaction of 4,5-dibromo-2-nitro-phenyfluorone（DBON-PF） with platium（Ⅳ） was studied and a spectrophotometric method for the determination of platinum was established. In the presence of CPB/OP microemulsion medium and in HAc-NaAc buffer solution at pH 3.6,platinum （Ⅳ） reacted with DBON-PF to form a stable pink complex with a molar ratio of 1 ： 2. The maximum absorption wavelength of the complex is at 476 nm . The apparent molar absorptivity is 1.88×105Lmol^-1·cm^-1. Beer＇s law is obeyed in the range of 0-14μg/10 mL for Pt（Ⅳ） and the detection limit is 1.06×10^-6g/L. The method has been applied to the determination of platinum in catalyst samples with the recovery from 97.6% to 105.0%, the relative standard deviation from 1.1% to 2.1%, and the results are in line with those obtained by atomic absorption spectrometry.