Simultaneous Determination of Six Triazolic Pesticide Residues in Apple and Pear Pulps by Liquid Chromatography with Ultraviolet Diode Array Detection

A method is described for the simultaneous determination of diclobutrazol, flusilazole, flutriafol, hexaconazole, paclobutrazol, and tetraconazole in apple and pear pulps used in baby food at a limit of 0.01 mg/kg. Apple and pear pulp samples are subjected to selective solid-phase microdispersion (SPMD) with SPE-ED Matrix-38 and acetone–cyclohexane, and the extracts are cleaned up on a Florisil cartridge with hexane–cyclohexane–acetone. The extracts are then analyzed by liquid chromatography with ultraviolet detection, using an octadecylsilane column with a gradient-programmed acetonitrile–water mobile phase. Recoveries were determined by spiking apple and pear pulps with the 6 pesticides under investigation at 0.1, 0.05, 0.03, and 0.01 mg/kg. Six determinations were performed at each level for each pesticide. Recoveries were ≥70% at the 0.01 mg/kg level.