Determination of Trace Amounts of Chlorobenzenes in Water Using Membrane-Supported Headspace Single-Drop Microextraction and Gas Chromatography-Mass Spectrometry

A novel method based on the coupling of membrane-supported headspace single-drop microextraction with gas chromatographyaEuro'mass spectrometry (GC-MS) is developed for the determination of chlorobenzenes in water samples. For the determination of five chlorobenzenes, a 15 mu L toluene microdrop was placed inside the plastic membrane and exposed for 10 min for headspace extraction while stirring at 1000 rpm. The microdrop was then picked up by a microsyringe and directly injected into the injector block of the GC-MS instrument. Under the optimized operation conditions, the calculated calibration curves gave a high level of linearity for all targets with correlation coefficients range from 0.9945 to 0.9987. The limits of detection range from 0.01 to 0.05 mu g/L and the RSDs for most of chlorobenzenes were below 7%. The method is simple, sensitive, and stable for single drop microextraction. Its applicability is demonstrated by the determination of chlorobenzenes in tap water samples.