Abstract: The silylation of polar analytes on the polymeric coating of SPME fiber could be performed directly by placing the fiber into the headspace of bis(trimethylsilyl)trifluoroacetamide(BSTFA) after SPME . The derivatization was carried out at room temperature without damaging the fiber. Compared with the diazomethane-SPME technique, it is a simpler, cheaper and environmental friendly. The kinetics of the reaction of silylation on SPME fiber coating was studied. The result indicated that the silylation was of pseudo first order kinetics. The reaction depends on the analytes concentration in the fiber coating. The experimental results also show that the new fiber coating has a high extraction efficiency for polar compounds but non-reactive with derivatizing reagents could be found.

Key words: Solid phase microextraction, GS-MS spectrography, Derivation, Silylation reaction kinetics