Lignin phenolic structures in natural orgainc matter (NOM) were characterized by a modified version of the classic alkali CuO oxidation method using HPLC. Vanillyl, syringyl and cinnamyl family groups consist of three phenolic strcutres each, an aldehyde, a ketone, and a carboxylic acid. Two types of commercially-available lignin materials were analyzed by this method for lignin monomers. One lignin material exhibited both vanillyl and syringyl units, while the other only produced vanillyl units. Laboratory chlorination of the lignin polymers and the simple monomers allowed quantitative assessments of the contribution of specific substructures to overall DBP formation. Most trihalomethane and haloacetic acid formation appeared to be attributable to identified monomeric constituents. In contrast, observed TOX formation far exceeded that which was predicted from the alkaline CuO fragments. Includes 17 references, tables, figures.