Novel chlorination by-products of aquatic humic substances

The formation of water soluble carbonyl compounds, which may be of toxicological concern, during chlorination of humic water at pH 2 and pH 10 was investigated. The carbonyl compounds have been directly derivatized in the aqueous phase with pentafluorobenzyl- O-hydroxylamine and the neutral products extracted with n-heptane at pH 7. Acidic products were extracted at pH 2 with ether and methylated. Analyses by capillary gas chromatography with mass spectrometric detection revealed the presence of a great variety of both neutral and acidic carbonyl compounds many of which have not been reported previously from chlorinated humic water. The distribution of chlorination products varies with pH for chlorination. Besides the known drinking water mutagen MX, two new chlorinated oxo-acids were identified.