关键词: QuEChERS；静电场轨道阱质谱；抗虫药；消炎药；糖皮质激素

Abstract: A method for the determination of 21 veterinary drugs in cow and goat milk and milk powder was established by the QuEChERS (quick, easy, cheap, effective, rugged, safe) sample pretreatment method combined with ultra performance liquid chromatography-quadrupole/orbitrap mass spectrometry (UPLC-Q/Orbitrap MS). Chromatographic conditions, mass spectrometric parameters and pretreatment conditions were optimized. Samples were extracted with acetonitrile in the presence of anhydrous sodium sulfate, purified using a mixture of primary secondary amine (PSA) and C18, separated on an Accucore RP-MS column (100 mm × 2.1 mm, 2.7 μm), and detected by UPLC-Q/Orbitrap MS. Good linearity was observed for all the analytes in the investigated concentration ranges with correlation coefficients (r2) of greater than 0.99. The limit of quantification (LOQ) of the proposed method was 0.5 μg/kg. The average recoveries at spiked concentration levels of 0.5, 2.0 and 10.0 μg/kg were 67.2%–110.2% with relative standard deviations (RSDs) of 3.6%–17.4% (n = 6). The method is simple and sensitive, and suitable for simultaneous detection of the 21 veterinary drugs in cow and goat milk and milk powder.

Key words: QuEChERS; electrostatic field orbitrap mass spectrometry; antiparasitics; antiphlogistics; glucocorticoids