Hydrophilic interaction liquid chromatography (HILIC) with DAD detection for the determination of relatively non polar fungicides in orange samples

A new, sensitive, rapid, economic and validated high performance liquid chromatography/ diode array detector (HPLC/DAD) method has been developed for the determination of five fungicides namely; Carbendazim (MBC), Thiabendazole (TBZ), Metalaxyl (MET), Imazalil (IMA) and Propiconazole (PCZ). The analytical method was carried on hydrophilic interaction liquid chromatography (HILIC) column using isocratic elution of acetonitrile and water. Prior extraction of orange samples was done using a mixture of diethyl ether and ethyl acetate as an extraction solvent in liquid liquid extraction. The total run time was 15 min which makes it suitable for routine analysis of MBC, TBZ and IMA in oranges. Procedural standard calibration was applied to compensate the matrix effect. In order to measure the lowest concentration of the investigated fungicides below maximum residue limits (MRL), HPLC parameters were optimized. Mean recoveries were obtained ranging from 99.32% to 101.08% with average %RSD < 5.27%. The selected fungicides' residual quantities were successfully measured using the suggested method in various markets and organic orange samples. The investigation of carbendazim's kinetics of degradation, as well as its half-life and predicted preharvest interval (PHI), in real orange samples obtained from orange trees after being treated with the investigated fungicides, is the first to separate relative nonpolar components using HILIC.