Comparison of in-tube sorptive extraction techniques for non-polar volatile organic compounds by gas chromatography with mass spectrometric detection

A commercial in-tube sorptive extraction device, known as solid-phase dynamic extraction (SPDE), has been evaluated for the extraction of non-polar volatile aromatic analytes from aqueous solutions in both headspace and liquid injection modes. An automated sampler is used with a gas-tight 2.5 ml syringe equipped with a special needle that is coated on the inside with a non-polar extraction phase. After absorption onto the phase, the analytes were thermally desorbed directly into a GC–MS system. The technique was evaluated for the determination of furan, benzene and toluene. The sensitivity for toluene was greatly improved on using SPDE compared to static headspace. A slight increase in sensitivity was observed for benzene but none for determination of furan. Estimated limits of detection ranged from 0.2 to 2 μg/l.