NEW SPECTROPHOTOMETRIC METHOD WITH KMnO4 FOR DETERMINATION OF HYPOCHLORITE IN COMMERCIAL BLEACHES
AbstractHypochlorite with a strong germicidal and bleaching action forms the active component in most commercial bleaches. The new method, an instrument-based and simple experimental procedure involves the reaction of the hypochlorite with arsenious oxide (As2O3) (pH 6.5) followed by the coupled reaction of residual As2O3 with permanganate at acidic pH. A titration procedure is described and spectrophotometric method is designed using four ranges of calibration curves to enable the determination of hypochlorite in the range 2.5 x 10-4 to 2.4 x 10-2 M from the KMnO4 absorbance measurements. A series of commercial bleaches are tested using the proposed spectrophotometric method. The results proved more precise and accurate than by arsenite method.
KEY WORDS: Commercial bleaches, Hypochlorite determination, Spectrophotometric method
Bull. Chem. Soc. Ethiop. 2005, 19(1), 1-8.