Rapid in situ determination of ClO2 in drinking water by improved solid DPD spectrophotometry

This research aims to realize the rapid detection of ClO2 content in drinking water by adopting improved solid DPD. This method is fast and convenient with low cost and less waste liquid. The results show that this method has good precision and sensitivity. The linear correlation coefficients of the cubic regression equation were all greater than 0.999. The detection limit of the method was 0.002mg/L ClO2. The relative standard deviations (RSD) of seven parallel tests were between 1.37% and 8.87%, and the relative errors were small. The recovery rate was 96.67~110%. The method could be used for the direct determination of water samples with a mass concentration of 0.02mg/L~2.00mg/L in drinking water after ClO2 disinfection.