Sorption of phenols to dissolved organic matter investigated by solid phase microextraction

The sorption of phenol and different halogenated phenols to natural organic matter of a brown water lake (HO14), of a compost extract, of Aldrich humic acid (Aldrich-HA), and to the protein bovine serum albumin (BSA) was investigated using solid phase microextraction (SPME). The limit of determination for the SPME analysis was < 15 microg/l for all phenols investigated. The extraction coefficients K(F) were calculated according to a first-order extraction kinetics. In general, the extraction equilibrium was established faster due to the presence of dissolved organic matter (DOM). The highest sorption capacity of phenols was observed for BSA with log K(OC) values in the range between 2 and 6. For the compost extract and HO14 only a small sorption of the investigated phenols was determined. On the other hand, Aldrich humic acid showed a reasonable sorption of phenols with log K(OC) values between 2 and 3. The sorption to DOM decreased when the pH of the solution was increased.