Hydrophobic organic micropollutants in samples of coastal waters: efficiencies of solid-phase extraction in the presence of humic substances

Solid-phase extraction (SPE) has been used to enrich organic micropollutants (hydrophobic chlorinated and polycyclic aromatic hydrocarbons, CHC and PAH) from coastal water samples and to systematically study the influence of humic substances (HS) on SPE. A reversed phase (RP) system with high flow rates (rapid chromatography, RC) was used to show the basic adsorption principles and interaction processes which influence the enrichment of organic compounds. A model humic substance was found to hinder the enrichment of individual hydrophobic micropollutants (MP), depending on their octanol-water distribution coefficient POW. This effect was found to be lower with natural humic substances. For longer contact time between water sample and adsorption material, the pollutant/humic substance bonding proved to be reversible.