过氧化氢氧化甲基红抑制动力学光度法测定痕量双酚A

摘要

A catalytic spectrophotometric method for the determination of trace bisphenol A was established based on the inhibitory effect of bisphenol A on the oxidation of methyl red by hydrogen peroxide in hydrochloric acid medium. The optimum kinetic condi-tions of the catalytic reaction has been investigated. The wavelength for the determination is 520nm. The linear range for determina-tion of bisphenol A is 0. 5~9. 0μg·mL-1 with the detection limit of 2. 27×10-9g·mL-1. The results from the studies suggested that the catalytic reaction was zero-order and the apparent activation energy of this reaction was 49. 26kJ·mol-1 ,and the apparent rate constant was 1. 21×10-3s-1. The procedure has been used to determine bisphenol A in extracts of mineral water bottle,with the rela-tive standard deviations of 2. 3% ~2. 7%and the recoveries of 96. 7% ~104. 0%.%基于过氧化氢在盐酸介质中可氧化甲基红,双酚A的加入可明显抑制该氧化反应的进行,据此建立了一种新的测定双酚A的抑制动力学分光光度法。研究了该催化褪色反应的最佳动力学条件和参数。在测定波长520nm下,测定方法的线性范围0．5~9．0μg·mL-1,检出限为2．27×10-9g·mL-1。催化反应为动力学零级反应,表现活化能为49．26kJ·mol-1,催化反应速率常数为1．21×10-3s-1。方法用于矿泉水瓶浸取液中双酚A的测定,相对标准偏差为2．3%~2．7%,加标回收率在96．7%~104．0%之间。