百里香酚兰示差光度法测定水中低浓度二氧化氯影响因素的研究

The influence factors research to the determination of low concentration chlorine dioxide in water by thymol blue spectrophotometry

近年来，二氧化氯作为饮用水的一种消毒剂越来越引起关注，因此迫切需要一种能够测定mg／L浓度级二氧化氯的方法．根据二氧化氯可氧化百里香酚兰使其褪色的特性，可用示差分光光度法测定水中低浓度二氧化氯的含量．百里香酚兰在碱性介质中，二氧化氯的浓度为0．00～2．50mg／L时，标准工作曲线线性度较好。利用本方法还研究了ClO2^-，ClO3^-和游离性有效氯等潜在干扰因素。实验表明，ClO2≤1.12mg/L,ClO3^-≤47.04mg／L，游离性有效氯≤0．48mg／L时，引起的干扰较小。

In recent years, the use of chlorine dioxide as a disinfectant for drinking water has become increasingly attractive. As a result, an accurate method for the determination of mg/L concentration of chlorine dioxide is needed. The low concentration of chlorine dioxide in water was determined by spectrophotometry according to the characteristic of decoloration of thymol blue by using chlorine dioxide as oxidant in this paper. The linearity of the standard working curve is good in the range of 0.00～2.50 mg/L chlorine dioxide concentration in the alkali medium. The interference factors to influence the determination of chlorine dioxide were also investigated. The experiment indicates that the interference is less when ClO2≤1.12mg/L,ClO3^-≤47.04mg/L, and free available chlorine≤0.48mg/L, respectively.