在弱碱性条件下 ,二氧化氯 (ClO2 )氧化氯酚红使其褪色 ,于 5 75nm波长处测定剩余氯酚红的吸光度 ,当用试剂空白参比时 ,吸光度的降低值与ClO2 的浓度呈直线关系 ,其它氧化剂在测定条件下无干扰 ,方法有较高的灵敏度和很好的选择性 .方法用于自来水样的测定 ,结果满意 . Under mild alkaline conditions, chlorine dioxide (ClO2) is oxidized with chlorophenol red to determine the absorbance of the remaining chlorophenol red at a wavelength of 575 nm. When the reagent blank reference is used, the decrease in absorbance and the concentration of ClO2 The results showed that there was a linear relationship among the other oxidants without any interference under the conditions of determination, and the method had high sensitivity and good selectivity. The method was applied to the determination of tap water samples with satisfactory results.