A 4-vinylpyridine-divinylbenzene (VP-DVB) resin was synthesized to be used for on-line solid-phase extraction process and it was tested for a group of polar compounds. The high specific surface area and the nitrogen content of the VP-DVB sorbent increased the interactions with the polar analytes in the preconcentration process. The sorbent enabled 100 ml of water to be concentrated with recoveries higher than 70% for several polar compounds (including phenol) except for oxamyl (55%) and methomyl (43%). The method was used to analyse water samples by liquid chromatography and UV detection. Linearity was good and detection limits were 0.1-0.2 microg l(-1) for all compounds. Several tap and river water and waste water treatment plant samples were analyzed; phenol and (4-chloro-2-methyl-phenoxy)acetic acid (MCPA) were tentatively determined in some samples.