VALIDATION OF THE IODOMETRIC DETERMINATION OF SODIUM HYPOCHLORITE IN DISINFECTANT SOLUTIONS

Abstract

Analytical validation establishes that the performance characteristics of a procedure meet the requirements for the intended applications under the specific laboratory conditions. It is a process, from its conception; rigorous, dependent on the technique, the matrix, the analyte, the concentration ranges, the parameters to be evaluated, the available infrastructure and the analyst. It is applied to analytical determinations on a finished product or its raw material. The fundamental parameters of an analytical validation are: selectivity, linearity and range, precision, accuracy and limits of detection and quantification: Robustness is a parameter of method tuning. Sodium hypochlorite is a chlorinated compound widely used as an active ingredient in bleaching agents. The classical method for quantifying the hypochlorite content in different samples is iodometric redox volumetry, with starch as indicator. It is a specific method for this analyte. The aim of the work is the validation of the establishment by suitability of the iodometric method for the determination of sodium hypochlorite in disinfectant solutions. The parameters considered were selectivity, precision through repeatability and reproducibility, accuracy, robustness, linearity, range and limits of detection and quantification. It was demonstrated that 85.7% of the parameters met the established acceptance criteria. The preparation time of the sodium thiosulfate titrating solution influenced the quantification of hypochlorite content. The iodometric method for determining sodium hypochlorite concentration in commercial samples is selective, precise, accurate and linear.