Determination of 15 high-risk pesticide and adjuvant residues in fruits from USA by solid phase extraction-ultra performance liquid chromatography-tandem mass spectrometry

A method was developed for the quantative determination of 15 high-risk pesticide and adjuvant (acephate, methomyl, thiamethoxam, thiabendazole, acetamiprid,simazine, pyrimethanil, fludioxonil, boscalid, methoxyfenozide, myclobutanil, fenhexamid, tetraconazole, piperonyl butoxide, chlorpyrifos) residues by SPE-ultra performance liquid chromatography-tandem mass spectrometry (SPE-UPLC-MS/MS). The samples were homogenized, extracted with acetonitrile, and cleaned-up by amino solid phase extraction column. The separation was performed on a Shimadu Shim-pack XR-ODS column (75 mm × 2.0 mm, 1.6 μm). The compounds were identified by MS/MS and multiple reaction monitoring (MRM) mode, and quantified by external standard method. The linearities of 15 pesticides and adjuvants were in the concentration range of 0.001-0.5 mg/L, with the correlation coeffecients higher than 0.999 5. At the fortified levels from 0.005 mg/kg to 0.5 mg/kg in pear, grape and apple, the average recoveries of all 15 pesticides and adjuvants ranged from 80% to 115% with the relative standard deviations varied from 5.5% to 16%. The limits of quantification (LOQs) of the analytes were ranged from 0.005 to 0.01 mg/kg. This method is simple, rapid, accutate and therefore, suitable for the confirmation and quantification of the 15 pesticides and adjuvants in fruits.