Determination of benzene in aqueous samples by membrane inlet, solid phase microextraction and purge and trap extraction with isotope dilution gas chromatography-mass spectrometry

The determination of benzene in aqueous samples is reported using membrane inlet, solid phase microextraction and purge and trap extraction techniques combined with gas chromatography-mass spectrometry. The membrane inlet and solid phase microextraction techniques have been applied to the analysis of soft drink samples and the performance characteristics of these methods compared to the established purge and trap method. Isotope dilution quantitative procedures with hexadeuterobenzene as internal standard were used in combination with all three sampling inlets. Detection limits were at, or below the parts per billion (mu g l(-1)) level with analytical precision (%RSD) in the range 3-8%.