CHARACTERIZATION OF AQUEOUS HUMIC SUBSTANCES BEFORE AND AFTER CHLORINATION

Five aquatic humic substances have been chlorinated and characterized by C-13 nuclear magnetic resonance spectrometry and pyrolysis gas chromatography-mass spectrometry. It is shown that methoxyl, phenolic, and ketonic structural groups are more reactive to chlorine than alkyl or carboxyl, which in turn are more reactive than carbohydrates. These results suggest that the choice of aryl, methoxyl, phenolic, and ketonic compounds as models for water chlorination studies are valid, even though it is now known that these structures often are not the most significant structural groups in humic substances.