DETERMINATION OF PHENOLS IN WATER BY ONLINE SOLID-PHASE DISK EXTRACTION AND LIQUID-CHROMATOGRAPHY WITH ELECTROCHEMICAL DETECTION

Poly(styrene-divinylbenzene) (PS-DVB) membrane extraction disks were u sed as sorbents for the on-line solid phase extraction of 13 phenols ( nitro and chlorophenols) in river and tap waters. Determination was pe rformed by liquid chromatography with electrochemical detection (LC-ED ). An acetate buffer-acetonitrile-methanol mixture as mobile phase and amperometric detection at +1100 mV were used. High water volumes, up to 250 ml, can be preconcentrated without loss of phenols (recoveries between 80% and 100%) except for the more polar ones. Moreover, detect ion limits between 0.01 and 0.1 mu g l(-1) in tap water and between 0. 1 and 1.0 mu g l(-1) in river water were obtained. The method has been applied to the analysis of two river water samples.