Solubility and partitioning studies with polycyclic aromatic hydrocarbons using an optimized SPME procedure

In order to determine the water solubilitiy (S-w) and octanol/water partition coefficient (K-ow) of polycyclic aromatic hydrocarbons, we have optimized the direct solid-phase microextraction (SPME) of selected compounds (fluoranthene (FLU), phenanthrene (PHE), pyrene (PYR), benz[a]anthracene (BaA), benz[a]pyrene (BaP), and coronene) from the matrices water and octanol-saturated water. By the use of a 100 mu m polydimethylsiloxane fibre and magnetic stirring of the sample with glass-coated mini-impellers in combination with gas chromatography we obtained limits of determination (GC-MS) comparable to standard HPLC procedures. Only coronene could not be quantified. The determined S-w of FLU agree with reference data; for B[a]P we have obtained a 2 to 3 times higher value than described in recent literature. The obtained K-ow values are close to reference data for both single components. For a mixture of FLU, PHE, PYR, and B[a]A the measured K-ow values are 0.2-0.3 log units below tabulated values for the single components.