NEW METHOD FOR THE FLOW INJECTION SPECTROPHOTOMETRIC DETERMINATION OF LOW CONCENTRATION CHLORINE DIOXIDE IN WATER USING METHYLENE BLUE

Abstract

A reverse flow injection spectrophotometric method for determination chlorine dioxide was developed with leucomethylene blue as the coloration reagent. By this method low concentrations of chlorine dioxide in water were determined in the presence of Cl₂ and anion species such as OCl⁻, ClO₂ ⁻ and ClO₃ ⁻. The linear range of ClO₂ measurement is 0–1.91 mg/L with a detection limit of 0.02 mg/L. The presence of chlorine and hypochlorite ion can be masked by using oxalic acid. Chlorate does not interfere with the measurement. The permissible maximum concentration of ClO₂ ⁻ is 3.0 mg/L.

Keywords:

• Chlorine dioxide
• Leucomethylene blue (LMB)
• Reversed flow injection
• Spectrophotometry

Acknowledgments