Solid-phase microextraction with on-fiber derivatization for the determination of hydroxy-polychlorinated biphenyl compounds in urine

A sensitive and solvent-free procedure for the determination of hydroxy metabolites of polychlorinated biphenyls (PCBs) in urine samples was studied using solid-phase microextraction (SPME) followed by on-fiber silylation and gas chromatography/mass spectrometry (GC/MS) determination. The analytical procedure involved headspace adsorption with coated fiber and headspace derivatization with bis(trimethylsilyl)-trifluoroacetamide (BSTFA) in a sample vial. Experimental SPME parameters such as selection of coating material, addition of salt, extraction time and temperature of adsorption were optimized. The optimum extraction conditions for hydroxy-PCBs were obtained with a polydimethylsiloxane/divinylbenzene (PDMS/DVB) coated fiber at 90 °C for 60 min in urine, added 10% sodium chloride. Derivatization of the hydroxy-PCBs with BSTFA was performed on the SPME fiber at 60 °C for 10 min. The calibration curves for derivatized forms showed good linearity in the range of 0.01-10 ng mL−1 and method detection limits proved to be 0.01-0.1 ng mL−1 in 2 mL of urine.