Method for Determination of 103 Pesticide Residues in Grapes using Liquid Chromatography-Tandem Mass Spectrometry

A liquid chromatographic method with electro spray ionization tandem mass spectrometry (ESI-MS-MS), has been reported for the simultaneous determination of 103 pesticide of 11 classes (organo phosphorus, triazine, pyrimidine, triazole, imadazole, benzimidazole, nicotinoid, substituted thiourea, strobiluron, dinitroaniline, morpholine) pesticide residues in grape puree. These were estimated in a Schedule multi reaction monitoring (Scheduled MRM) mode. These were separated on reverse phase C-18 column using binary gradient solvent system. Samples were extracted with ethyl acetate and cleaned up by dispersive solid phase extraction with primary secondary amine. The analytical performance of method was demonstrated by fortification at four levels for each pesticide, ranging from 5.0 to 50.0 ng g⁻¹. Mean recoveries were from 60 to 115% for all pesticides except dodine(45%), with associated precision RSD below 13%. The limit of quantification (LOQ) of all pesticides was ≤ 5.0 ng g⁻¹ except for abamectin, flubendiamide, lufenuron and thiometon, where LOQ was 10.0 ng g⁻¹. A total 20 min run time liquid chromatography method was successfully applied for analysis of proficiency and real fresh grape samples for incurred residues.