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

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 ClO_2~-1.12?mg/L,ClO_3~-(47.04?mg/L,) and free available chlorine0.48?mg/L,respectively.