Abstract:

A method for the determination of sulfonamide potentiators, trimethoprim (TMP), diaveridine (DVD) and ormetoprin (OMP), in different animal origin food matrices (including chicken muscle, fish muscle, chicken liver, egg and milk) has been developed by ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The sample was extracted by formic acid-acetonitrile (1:9, v/v), cleaned-up by hexane, separated on an Acquity UPLC BEH C18 column (50 mm×2.1 mm, 1.7 μm) with gradient elution. The determination was carried out with electrospray ion source under the positive mode and multiple reaction monitoring (MRM) mode. The extraction recoveries of three extraction solvents were observed. The purification condition and concentration condition were optimized. In addition, the mobile phase, column temperature and solid phase extraction column were studied. The calibration curves showed a good linearity in the range of 1.25-30.0 μg/L, and the correlation coefficients (r) were higher than 0.99. The limits of quantification (LOQ, S/N=10) of the three potentiators were 5.0 μg/kg. At the spiked levels of 5.0, 10.0 and 20.0 μg/kg, the recoveries of the three potentiators were ranged from 61.2% to 108.5%, and the relative standard deviations (RSD, n=6) ranged from 1.1% to 9.8%. The results indicate that the method is simple, rapid, sensitive and suitable for the qualitative and quantitative analysis of the three potentiators in multiple matrices.

Key words: animal origin foods, sulfonamide potentiators, ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS)