Applications of LC/ESI-MS/MS and UHPLC QqTOF MS for the Determination of 148 Pesticides in Berries†

Applications of liquid chromatography electrospray ionization tandem mass spectrometry (LC/ESI-MS/MS) and ultrahigh-pressure liquid chromatography electrospray ionization quadrupole time-of-flight mass spectrometry (UHPLC QqTOF MS) for the determination of 148 pesticides in berry fruits are presented in this study. Pesticides were extracted from berries using a procedure known as QuEChERS (quick, easy, cheap, effective, rugged, and safe). Quantification, with an analytical range from 5 to 500 microg/kg, was achieved using matrix-matched standard calibration curves with isotopically labeled standards or a chemical analogue as internal standards. The method performance parameters, which included overall recovery, intermediate precision, and measurement uncertainty, were evaluated according to a designed experiment, that is, the nested design. For LC/ESI-MS/MS, 95% of the pesticides studied had recoveries between 81 and 110%, 98% of the pesticides had intermediate precision of <or=20%, and 95% of the pesticides showed measurement uncertainty of <or=40%. Compared to LC/ESI-MS/MS, UHPLC QqTOF MS showed a relatively poor repeatability and large measurement uncertainty. Ninety-five percent of the pesticides analyzed by UHPLC QqTOF MS had recoveries between 81 and 110%, 86% of the pesticides had intermediate precision of <or=20%, and 83% of the pesticides showed measurement uncertainty of