Determination of Total Chlorine in Drinking Waters by Gas Chromatography

Abstract

In the procedure developed, chlorine species belonging to so-called total chlorine in the chlorinated water react with KBr, then in the presence of acetone and sulphuric acid, the released bromine forms a propanone derivative. This latter is extracted into toluene, separated by gas chromatography, and measured using an electron capture detector. For the preparation of calibrating standards chloramine T trihydrate of appropriate purity can be used. The limit of detection was found to be 0.285 µmol/L Cl2. For total chlorine concentrations between 10 and 50 µmol/L, the relative standard deviations were 4% at the most. Although selectivity of the method generally meets the practical requirements, a few strong oxidizing agents interfere with the determination (e.g., ).