RESEARCH ON DETERMINATION METHOD OF ACTUAL CONCENTRATION OF CHLORINE DIOXIDE IN USING LIQUID

Objective To study the determination method of the actual concentration of ClO2 in the using liquid which was diluted by activated stabilized chlorine dioxide solution.Methods Spectrophotometry was used to determine the contents of hypochlorite(ClO-(Cl2)),chlorite(ClO-2),chlorate(ClO-3)and chlorine dioxide in the using liquid which was diluted by activated stabilized chlorine dioxide solution.Then results were compared with the measurement results with malonate as a masking reagent.Results The chlorate(ClO-3) did not interfere with determination of the actual concentration of ClO2 in using liquid.When the pH value was higher than 3.56,chlorite(ClO-2) did not interfere with the determination in the range from 359 nm to 500 nm;when the range of pH was from 2.00 to 8.30,hypochlorite(ClO-) has no absorption in the range from 375 nm to 500 nm and did not interfere with the determination.Conclusion The actual concentration of ClO2 in using liquid that diluted by activated stabilized chlorine dioxide solution can be measured directly at 375 nm without adding masking reagent.