SIMULTANEOUS DETERMINATION OF 27 PHENOLS AND HERBICIDES IN WATER BY HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY WITH MULTIELECTRODE ELECTROCHEMICAL DETECTION

A sensitive and simple method for the simultaneous evaluation of phenol, 26 substituted phenols and herbicides was developed using HPLC and electrochemical detection. After extraction from the samples on solid-phase cartridges, the compounds were separated on a reversed-phase column by using a combined gradient of organic modifier and counter-ion. The total analysis time was less than 63 minutes. Identification of the compounds was based on retention time comparison with authentic standards. In addition, further confirmation of peak identities and of their purity was determined by comparison of the ratio of the peak's height of each compound across the electrode array, with the similar ratio of the authentic standard. The detection limit was found to be much lower than that indicated by the European Community: for the least sensitive compound (a herbicide, Linuron) it was less than 0.0005 mu g/l at signal-to-noise of 3. The method was used to examine the residual levels of phenylurea herbicides, phenol, chloro- and nitro-phenols in tap water, mineral water and spring water from different sources.