A rapid screening and quantitative method was developed for the determination of paraquat in vegetables by ultra performance liquid chromatography-quadrupole/electrostatic field orbitrap high resolution mass spectrometry(UHPLC-Q-Exactive MS).The vegetable samples were extracted twice with acetonitrile -0.2% formic acid(1∶1

by volume)

and cleaned up by dispersive solid phase extraction with N propyl ethlene diamine(PSA) and C18.Separation of the target compounds was performed on an Acquity UPLC BEH HILIC(100 mm×2.1 mm

1.7 μm) column with acetonitrile and 0.2% formic acid containing 50 mmol/L ammonium formate as mobile phases by gradient elution.The quantitative and qualitative analysis were carried out by high resolution mass spectrometry with electrospray ionization(ESI) source in positive ion acquisition mode under parallel reaction monitoring(PRM) mode.Results showed that there were good linear relationships for paraquat in different vegetables matrixes in corresponding concentration ranges with correlation coefficients(r2) of 0.992 7-0.999 4.The limits of detection(LOD) and the limits of quantitation(LOQ) were in the ranges of 0.1-0.5 μg/kg and 0.4-1.8 μg/kg

respectively

while the recoveries ranged from 70.8% to 113% with relative standard deviations(RSD) of 0.30%-7.9%.The method is simple and rapid

and could be used for the quick screening and quantitative analysis of paraquat in vegetables.