PESTICIDE RESIDUES IN RASPBERRIES AND LETTUCE: EXTRACTION AND COMPARISON OF THREE CHROMATOGRAPHIC METHODS: HPLC, HPTLC AND GC

The determination of iprodione, vinclozolin, and cymoxanil fungicide residues in raspberries and lettuce has been carried out by HPLC with an UV detector, by HPTLC with an densitometric detection, and by GC with an electron capture detector (ECD). In all cases, fungicide residues were extracted with acetone and liquid-liquid partitioning process and finally purified on silica gel. Recoveries are always higher than 70%. For iprodione, vinclozolin, and cymoxanil, respectively, the limits of detection were 0.01 ppm, 0.013 ppm, and 0.08 ppm for the HPLC method, 0.2 ppm, 0.43 ppm, and 0.5 ppm for the HPTLC method, and 0.025 ppm, 0.004 ppm, and 0.03 ppm for the GC method.