ABSTRACT
A method of ultra performance liquid chromatography-quadrupole-time of flight-mass spectrometry ( UPLC-Q-TOF MS) was developed to determine 35 kinds of illegally added chemical fungicides in pesticide formulations. The samples were pretreated based on the ultrasonic extraction by the solvent of methanol, and then separated on a Zorbax C18(100 mm×1. 8 mm, 2. 1 μm) column by a gradient elution with 0. 1% formic acid aqueous solution and acetonitrile as the mobile phase. The mass spectrometer was operated under positive mode. Under the optimal conditions, the recoveries at three spiked levels (0. 2, 0. 4, and 2. 0 mg/kg) were in the range of 81. 0%-101. 3% and the RSDs were 1. 0%-4. 4%. Based on the developed method, 100 samples were analyzed, and among which 6 samples were screened out chemical fungicides. The proposed method was high-efficient, accurate and reliable for the qualitatively screening of illegaly added chemical fungicides.