Abstract:A method for determination of 116 pesticides and 24 biotoxin residues in aquatic product and dried aquatic product by ultra high performance liquid chromatography coupled with quadrupole/exactive orbitrap mass spectrometry (UPLC-Q exactive orbitrap MS) was developed. During the sample preparation, a novel lipid removal product was applied, and also QuEChERS extraction was involved. The sample was firstly extracted followed by acetonitrile (containing 30% (V/V) water), cleaned up by enhanced matrix removal of lipids (EMR-Lipid), and concentrated using syncore analyst. The separation of 140 target compounds was performed on a C18 column using gradient elution of 5 mmol/L ammonium formate in methanol (containing 0.1% formic acid) and 5 mmol/L ammonium formate water (containing 0.1% formic acid) as mobile phase. In the process of quantification and qualification, a full MS/dd-MS2 experiment was adopted in mass spectrometry acquisition, the chromatographic peak area obtained by extracting the accurate mass number of parent ions by full MS first-order mass spectrometry was quantified, and the retention time and dd-MS2 data were qualitatively confirmed by the second-order ionization mass spectrometry obtained by daughter ion scanning. The mass accuracy error was less than 3×10-6, and the calibration curves were linear well with correlation coefficient over 0.991. The limits of detection ranged from 0.02 µg/kg to 0.4 µg/kg. The average spiked recoveries for 140 target compounds were between 70.1% and 109.1%, with relative standard derivations (RSDs) from 1.0% to 14.1%. The results of the methodology met the requirements of GB/T 27417-2017. Compared to previous methods, the new procedure is characteristics of simple sample preparation and higher sensitivity.
