Characterization of AOX by Fractionation Analysis and Size-exclusion Chromatography

Abstract

A characterization method for AOX in surface water samples was developed and tested. The method involves fractionation using a hydrophobic C18 resin and a weak anionic exchange resin and allows the fractionation of the AOX pool of surface water samples into four fractions: (1) hydrophilic acidic, (2) hydrophilic non-acidic, (3) hydrophobic acidic, and (4) hydrophobic non-acidic. The adsorption analysis was verified with AOX-relevant model compounds and was applied to characterize the AOX pool of a stream sample from the Moskva river (Russia). In addition to the fractionation analysis, size-exclusion chromatography was used to characterize the AOX pool of the sample studied. Hydrophilic acids made up the major fraction of the AOX pool (55%). Among this fraction chlorinated high-molecular acids (humic substances) made up the main fraction (35%).