RESUMO
A fast sample pretreatment method by fast pesticide extraction (FaPEx) method combined with ultra-performance liquid chromatography-quadrupole-time of flight mass spectrometry was developed for screening of unknown pesticide residues in imported grains. The samples were extracted with 1% (v/v) acetic acid acetonitrile solution, cleaned-up by solid phase extraction column with FaPEx cartridges, and determined by UPLC-Q-TOF. The data was compared with the library with the accurate mass, isotopic distribution, fragmentation information and retention time. The results showed that this method can be used for the rapid screening of pesticide residues in imported grains without the reference standards, and it was applied to the actual screening of imported grain samples. The method is high efficiency, sensitivity and accuracy, which can meet the requirement for the rapid screening of pesticide residues in imported grains.