Headspace solvent microextraction of trace amounts of BTX from water samples

Headspace solvent microextraction (HSME) is an excellent preconcentration method for the analysis of BTX (benzene, toluene, p-xylene and o-xylene) in aqueous matrices by gas chromatography (GC). A droplet of benzyl alcohol containing methylcyclohexane as an internal standard was used for extraction. Analytes were extracted by suspending a 3 muL droplet directly from a microsyringe tip over the surface of the solution placed in a sealed vial. After extraction, the droplet was retracted back into the syringe and injected directly into a GC injection port. Experimental conditions have been optimised and their influence on the analyte peak-to-internal standard peak ratio have been studied. The linear range and the precision of the method were examined.