Chemical Changes of Organic Compounds in Chlorinated Water. IV. Gas Chromatographic and Mass Spectrometric Identification and Determination of Some Chlorinated and Oxidation-ruptured Compounds formed during the Reactions of Naphthols and Aqueous Hypochlorite

Abstract

Reactions of chlorine and naphthols, as model compounds in aquatic environmental pollutants, in dilute aqueous solution were investigated by means of gas liquid chromatography (GLC) and mass spectrometry (MS). Naphthols consumed a large amount of chlorine at neutral pH during the first 30 min, followed by much slower secondary reactions. After reacting for 24 h at 20°C, chlorine demands of α-and β-isomers were 14.2 and 7.7 mol of HOCl/mol of compound in the buffered water at pH 7, respectively. However, these demands lowered to 8.0 and 4.4 in the non-buffered water, which was characterized by a decrease in pH during the reactions. GLC and MS analyses for ether extracts obtained from the chlorine-treated naphthol solutions indicate that the reactions involve chlorination to mono-and dichlorinated naphthols (A), oxidation to chlorinated naphthoquinones (B), oxi-degradation of the compounds B to the aromatic carboxylic acids and dimerization of the compounds A and B. In addition, it was found that the reactions were dependent on the solution pH, molar ratios of HOCl/compound, and reaction time.