Abstract: A method was developed for the determination of fluoxastrobin and fluacrypyrim residues in fruits and beverages by ultra performance liquid chromatography with photo-diode array (UPLC-PDA) detection. The sample was extracted with ethyl acetate-cyclohexane (1∶1, v/v) by ultrasonic, cleaned-up by gel permeation chromatography (GPC), and then determined by UPLC-PDA. The quantification was performed by external standard. A BEH C18 colunm (50 mm×2.1 mm, 1.7 μm) was used, and water-acetonitrile (3∶7, v/v) was used as mobile phase at a flow rate of 0.3 mL/min. The column temperature was set at 40 ℃, and ultraviolet absorption wavelength was set at 251 nm. The calibration curves were linear between the peak area and the concentration in the range of 0.05-2 mg/L for fluoxastrobin and fluacrypyrim, the correlation coefficients were greater than 0.999. The average recoveries spiked in fruit and beverage matrices at the three concentration levels of 0.01, 0.05, 0.1 mg/kg ranged from 82.60% to 101.11% with the relative standard deviations of 5.4%-15.3%. The limits of detection (LOD) were not greater than 6 μg/kg and the limits of quantification (LOQ) were not greater than 20 μg/kg in fruit and beverage matrices for fluoxastrobin and fluacrypyrim.

Key words: beverage , fluacrypyrim, fluoxastrobin, fruit, gel permeation chromatography (GPC), pesticide residues, ultra performance liquid chromatography (UPLC)