罗丹明S酶催化光度法测定过氧化氢

Enzyme catalysis-spectrophotometric determination of H_2O_2 with rhodamine S

在pH4．4的HAc—NaAc介质中，以辣根过氧化物酶（HRP）催化H2O2氧化KI生成I2，过量的I^-与I2结合形成I3^-，而I3^-与罗丹明S（RhS）反应形成RhS—I3缔合微粒，该微粒导致体系在526nm处的吸收值线性降低，据此建立了检测H2O2的分光光度分析新方法。研究了PH值，HRP，KI及RhS用量等因素对体系的影响，并对水中Cu^2＋，Zn^2＋，Ca^2＋，Fe^2＋，Mg^2＋，Al^3＋等常见离子进行了干扰试验。在最佳实验条件下，H2O2的浓度在36．72～734．4μg／L范围内与吸光度降低值呈良好的线性关系，相关系数为0．9917。方法的检出限为10μg／L。该法用于测定废水中过氧化氢，结果与纳米金光度法的结果相一致。

In HAc-NaAc buffer solutions at pH 4.4, the oxidizing reaction between H2O2 and KI was catalyzed by horseradish peroxidase （HRP） to generate I2, which combined with excessive I^- and formed I3^-. And the I3^- reacted with rhodamine S （RhS） to produce RhS-I3 association particles, causing linear decrease of absorption value at 526 nm. Consequently, a spectrophotometric method was proposed to detect H2O2. The influence of pH, HRP, KI and RhS concentrations, and the interference of Cu^2＋ , Zn^2＋ , Ca^2＋ , Fe^2＋ , Mg^2＋, AL^3＋ on the determination were examined. Under optimal experimental conditions, H2O2 concentration in the range of 36.72--734.4 μg/L is linearly correlated to the decreasing absorption value, with the correlation coefficient of 0. 991 7. This method was applied to analysis of H2O2 in waste water samples, whose result was consistent with nano-gold spectrophotometric method.