Multiclass residues screening of 105 veterinary drugs in meat, milk, and egg using ultra high performance liquid chromatography tandem quadrupole time-of-flight mass spectrometry.

A high-throughput and robust method for analyzing multiclass residues of veterinary drugs in meat, milk, and egg by ultra-high performance liquid chromatography (UHPLC)-quadrupole time-of-flight mass spectrometry (QTOF) was established. The method successfully applied to the screening, quantification, and confirmation of 105 compounds from 9 different classes of drugs, including beta-agonists, benzimidazoles, corticoides, triphenylmethane, nitromidazoles, quinolones, sulfonamides, tetracylines, and benzodiazepams. The samples are extracted by a single extraction using acetonitrile containing 0.1% formic acid, followed by an easy solid phase extraction (SPE) clean-up on HLB column and finally analyzed by LC/MS QTOF MS. The separation was achieved within 30 min at the optimized chromatographic conditions. More than 92% compounds in this study can be reliably identified based on accurate mass measurement (within the 3 ppm mass error) at the 5 µg/kg concentration levels in the complex food matrix with further MS/MS confirmation. Our study demonstrated a reliable, high-efficient and high-sensitive strategy for the fast and high throughput screening of multiclass of veterinary drugs in foodstuffs of animal origin.