Applications of Ultra-performance Liquid Chromatography Electrospray Ionization Quadrupole Time-of-Flight Mass Spectrometry on Analysis of 138 Pesticides in Fruit-and Vegetable-Based Infant Foods

摘要

The applications of ultra-performance liquid chromatography electrospray ionization quadrupole time-of-flight mass spectrometry(UPLC QqTOF)in the determination of 138 pesticides in fruit-and vegetable-based infant foods were investigated.Pesticides were extracted from infant foods using a procedure known as the quick,easy,cheap,effective,rugged,and safe(QuEChERS)method.UPLC QqTOF MS full-scan with a relatively high sensitivity proved to be an ideal tool for screening of a large number of pesticides in a single analysis.UPLC QqTOF MS/MS provided product ion spectra that allowed for unequivocal confirmation of pesticides.Quantification was achieved using matrix-matched standard calibration curves with isotopically labeled standards or a chemical analogue as internal standards.The method performance parameters that included overall recovery,intermediate precision,and measurement uncertainty were evaluated according to a designed experiment,that is,the nested design.Generally,about 90% of the pesticides studied had recoveries between 81 and 110%,90% had intermediate precision of <25%,and 85% had measurement uncertainty of <50%.Compared to LC-ESI-MS/MS,UPLC QqTOF MS showed a relatively poor repeatability and large measurement uncertainty for quantification.In general,UPLC QqTOF can be used for screening,quantifying,and confirming pesticides in infant foods at 10 mu g/kg.