IDENTIFICATION OF COMPOUNDS IN MUTAGENIC EXTRACTS OF AQUEOUS MONOCHLORAMINATED FULVIC-ACID

Although monochloramine has been considered as an alternative disinfectant to chlorine, little is known about the identity of the byproducts from its reaction with natural organics. In this study, byproducts in mutagenic extracts of monochloraminated aqueous fulvic acid were identified by high-resolution gas chromatography/mass spectrometry (HRGC/MS). These analyses resulted in the identification and quantification of the potent bacterial mutagen 3-chloro-4-(dichloromethyl)-5-hydroxy-2(5H)furanone (MX), and the related compounds, (E)-2-chloro-3-(dichloromethyl)-4-oxobutenoic acid (EMX), (E)-2-chloro-3-(dichloromethyl)butenedioic acid (ox-EMX), and 2,3-dichloro-4-oxobutenoic acid (mucochloric acid). The compounds MX, EMX, and ox-EMX accounted for 9%, 26%, and 2%, respectively, of the mutagenic activity of the monochloramination extracts. Several short-chain (C2-C-9) aliphatic chlorinated organic acids, alcohols, and aldehydes were also identified. Of these, the alkenoic acids may be of toxicological significance because of their structural similarity to the open oxobutenoic form of MX.