Complexation-flocculation combined with microwave-assisted headspace solid-phase microextraction in determining the binding constants of hydrophobic organic pollutants to dissolved humic substances.

The binding constants, K-DOC, of selected polycyclic aromatic hydrocarbons (PAHs)-phenanthrene, anthracene, fluoranthene, and pyrene-to dissolved humic substances (DHS) were determined by complexation-flocculation combined with microwave-assisted headspace solid-phase microextraction (CF-MA-HS-SPME). The results obtained are comparable with K-DOC data reported in the literature. No disruption of the PAH to DHS binding equilibrium was observed during the complexation-flocculation process. The present study, which is the first to determine K-DOC by CF-MA-HS-SPME, provides an alternative approach to determine the K-DOC of PAHs. CF-MA-HS-SPME provides some advantages over other methods, such as no limitation of fluorescent compounds, greater determination speed, and the capability of measuring various compounds simultaneously.