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.

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 <or=25%, and 85% had measurement uncertainty of <or=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 microg/kg.