ION-PAIR REVERSED-PHASE LIQUID-CHROMATOGRAPHY WITH FLUOROMETRIC DETECTION OF PESTICIDES

The pesticides asulam, propoxur, coumatetralyl, biphenyl-2-ol and thiabendazole were separated by ion-pair reversed-phase liquid chromatography with fluorescent detection. The mobile phase contained methanol, acetic acid and sodium cholate as ion-pair reagent. In addition, tetramethylammonium hydrogensulphate and triethylamine were added to elute the pesticides. Separations were accomplished in less than 20 min. Interferences from nineteen pesticides were studied and recoveries from synthetic mixtures ranging from 90 to 110%. Recoveries from spiked apples and wheat grains ranged from 94 to 105% with relative standard deviations between 1.4 and 9.2% and detection limits between 0.1 and 1.9 ng.