Environmental monitoring of benzene, toluene, ethyl benzene and xylenes (BTEX) in river and well water samples were performed by solid-phase microextraction (SPME) coupled with capillary gas chromatography. For this purpose a novel SPME fiber was prepared based on imidazolium ionic liquids loaded on hollow fiber membrane pores using sol-gel formulation. Copper wire was used as mechanically durable support. Analytical merits of the method, including high correlation coefficients (0.9922-0.9943) and low detection limits (0.04-0.15 μg L-1), made the proposed method suitable for the trace determination of BTEX.