Determination of sulfoxaflor residues in melon and eggplant by ultra-high performance liquid chromatography-tandem mass spectrometry

It is verified that GB/T 20769-2008 is also suitable for the determination of the residue of sulfoxaflor in the samples of cantaloupe and eggplant and simplied the pretreatment steps. Samples of melon and eggplant were initially extracted with acetonitrile, salting out by Na Cl, cleaned up by aminopropyl ( NH2) cartridge, eluted by methanol and dichloromethane ( 5∶ 95, v∶ v) , metered by methanol and water ( 1 ∶ 1, v ∶ v) . After filtered with a 0.2 μm membrane, the resulting samples determined by UPLC-MS/MS performing on negative electrospray ionization and the multiple reactions monitoring mode ( MRM) .The matrix-matched external standard calibration curves were used for quantitative analysis.The linearly dependent coefficient r of sulfoxaflor for cantaloupe and eggplant were 0.9998 and 0.9992, respectively.The added recoveries were between81.00% ¹07.76% in the concentration range of 50 ~ 500 μg/L. The lowest limit of detection ( LOD) was 0.72 μg/kg and0.62 μg/kg, and the relative standard deviations ( RSD, n = 6) were in the range of 2.56% ~ 3.82%. The method can meet the requirements for determination of sulfoxaflor residue in cantaloupe and eggplant, and it is a quick, easy, effective, sensitive and accurate method.