Comparative evaluation of liquid chromatography versus gas chromatography using a beta-cyclodextrin stationary phase for the determination of BTEX in occupational environments.

An HPLC method for the determination of benzene, toluene, ethylbenzene and o-xylene, m-xylene and p-xylene in occupational environments was developed and compared with a GC-MS method. Chromatographic analysis using a beta-cyclodextrin stationary phase was performed after active and passive air sampling by adsorption on activated charcoal and pressurized fluid extraction. The analytes were completely separated and quantified using both methods, although GC-MS provided better resolutions and lower detection limits than HPLC. The HPLC method was unsuccessfully applied to the determination of benzene in real samples because its sensitivity was too low. Both methods were applied to the analysis of certified reference materials and air samples collected in several workplaces. Statistical comparison showed that HPLC and GC-MS provided analogous accuracy.