Development a HPLC Method for Simultaneous Determination of Azinphose methyl, Diazinon, Phosalone and Chlorpyrifos Residues in Fruit

A high-performance liquid chromatography with ultraviolet detection (HPLC/UV) method which was used solid-phase extraction for cleanup, was developed for the determination of Azinphos methyl, Phosalone, Diazinon and Chlorpyrifos residues in fruits. A full factorial experimental design was used for development of HPLC condition and evaluation of effect of three factors (pH of mobile phase, percent of acetonitril in mobile phase and flow rate) on the retention time and resolution of peaks. The samples were extracted with Hexan/Aceton(50/50)and then is loaded onto a C18 end-caped SPE cartridge for further clean up. For SPE condition optimization, several solvents (acetonitril, dichloromethane, ethyl acetate and hexane) were tested as eluent and the best recovery was found with hexane. The optimum HPLC condition was achieved with acetonitril: water (60:40) as mobile phase, flow rate 1 ml/min, on C8 column. The standard calibration curves were linear between 0.05-1μg/ml for Azinphos methyl and 0.1-2 μg/ml for others. The hexan:acetone extraction followed by the C18 end-cap SPE cleanup provided recoveries of >70% for all of pesticides and removing the greatest number of sample matrix interferences.