COMPARATIVE-STUDY OF ONLINE SOLID-PHASE EXTRACTION FOLLOWED BY UV ANDELECTROCHEMICAL DETECTION IN LIQUID-CHROMATOGRAPHY FOR THE DETERMINATION OF PRIORITY PHENOLS IN RIVER WATER SAMPLES

A comparative study between UV and electrochemical (EC) detectors was carried out for the determination of 16 priority phenols in water samp les. Polystyrene was used as a sorbent in on-line solid phase extracti on followed by liquid chromatography with UV and electrochemical detec tion (LC-UV and LC-EC, respectively). Detection limits down to 1 ng/l were obtained for all chlorinated phenolics with 100 ml sample volume. By reducing the sample volume to 10 ml it was possible to detect phen ol at 0.02 mu g/l. Values below the concentration levels required by c urrent legislation were obtained for all target compounds in LC-EC exc ept for nitrophenols because the selected working potential was not op timal for these compounds.