The ability of a novel sorptive polymer to determine the freely dissolved fraction of polar organic compounds in the presence of fulvic acid or sediment

A novel plastic material, poly(ethylene-co-vinyl acetate-co-carbon monoxide) (PEVAC), was evaluated as an absorptive passive equilibrium sampler for determination of the freely dissolved fraction of seven polar organic contaminants (POCs) in the presence of fulvic acid and sediment. The seven compounds selected were imidacloprid, carbendazim, metoprolol, atrazin, carbamazepine, diazinon and chlorpyrifos, i.e. a mixture of pharmaceuticals and pesticides having logarithmic octanol/water partition coefficients (log K (OW)) ranging from 0.2 to 4.77. The experiments demonstrated that the PEVAC sampler is well suited for determination of the freely dissolved fraction of chemicals in aquatic environments. Generally, the freely dissolved fraction of the POCs decreased with increasing hydrophobicity. However, strong interactions with functional groups of the organic matter seemed to dominate the partitioning for imidacloprid and carbendazim, having logarithmic dissociation partition coefficient log D < 1.47, and for metoprolol, which is positively charged at neutral pH.