DETERMINATION OF PHENYLUREA HERBICIDES IN DRINKING WATERS BY HPLC ANDSOLID-PHASE EXTRACTION

An HPLC procedure for determining phenylurea herbicides in waters is d escribed. A LichroSpher RP select B octadecyl-silane analytical column and spectrophotometric detection at 247 nm were used. Adequate retent ion was achieved with a mobile phase containing ACN/H2O 35/55 (v/v) an d 10(-2) M phosphate (pH = 7). The herbicides were isolated from water samples by using a single solid phase extraction procedure with C-18 solid-phase columns. An enrichment factor of 333 is achieved. The coef ficients of variation of the method were lower than 8% at 3 mu g L-1 h erbicides concentration level. Recoveries ranged. between 93 and 105%. The results obtained indicate that the proposed method is well suitab le for monitoring phenylureas in compliance with the European Communit y standard for drinking water.