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.