A simple and rapid method based on direct transfer of headspace vapor into the GC injector: application for determination of BTEX compounds in water and wastewater samples

A direct, inexpensive and solventless method based on headspace extraction coupled to gas chromatography-flame ionization detection (GC-FID) was developed for determination of benzene, toluene, ethylbenzene and xylenes (BTEX). In this method, volatile organic compounds are separated from the matrix and preconcentrated in the headspace of the sample solution. Then, the headspace vapor is transferred into the GC injector using a fused silica capillary tube. The parameters affecting the headspace extraction such as extraction time, extraction temperature, stirring rate, sample volume, transfer line tubing diameter, transfer line depth in the injector and salt addition were carefully investigated and optimized. The limits of detection (LODs) for the studied compounds ranged from 0.1 to 0.3 ng mL(-1) for 15 mL sample solution with the relative standard deviations (RSDs) ranging from 3.34 to 7.18% (n = 5). Finally, the optimized method was successfully applied to water and wastewater as real samples.