On-line combination of aqueous-sample preparation and capillary gas chromatography

An overview is presented of methods currently in use to combine the prepara tion of aqueous samples on-line with capillary gas chromatography. Two appr oaches can be distinguished: heartcut-orientated reversed-phase liquid chro matography-gas chromatography (GC) and analyte-isolation-orientated analyte extraction-GC. These approaches either use techniques in which water is di rectly introduced onto the GC column, or an indirect approach in which wate r is eliminated, i.e., by solid-phase extraction, solid-phase microextracti on or liquid-liquid extraction, prior to introduction of the analytes onto the GC column. The latter type of approach is much more successful and user friendly, and many applications have been reported. (C) 1999 Elsevier Scie nce B.V. All rights reserved.