Simultaneous determination of 120 veterinary antibiotics in meat by combined pretreatment system coupled with ultra-performance liquid chromatography-tandem mass spectrometry

Abstract

A comprehensive pretreatment system was developed to simultaneously extract and purify 120 veterinary antibiotics, possessing various physicochemical properties in eight categories. This system was coupled with ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) for the detection of the antibiotics. The samples were dissolved and dispersed by a Na2 EDTA-Mcllvaine buffer, extracted with acetonitrile containing 1.5% (v/v) formic acid, and cleaned using an Oasis PRiME HLB SPE system followed by n-hexane liquid purification. The separation of residue targets was performed on an Atlantis® T3 column (100 mm×2.1 mm, 3 μm) with a gradient elution of 0.1% (v/v) formic acid aqueous solution and acetonitrile as mobile phases and detected by UPLC-MS/MS with the multiple reaction monitoring (MRM) mode via ESI+ ionization. The pH of the extraction solvent and the purification method were optimized to promote the target recoveries. All targets showed good linear ranges from 1.0 to 50.0 μg/L, while all their correlation coefficients (r2) were higher than 0.9953, including r2 values of 89 targets being over 0.9990. The limits of quantification (LOQs) of seven targets were 10.0 μg/kg; 21 targets, 5.0 μg/kg; and the remaining 92 targets, not higher than 2.0 μg/kg. The average recoveries on three spiked levels (low, medium, and high) for all targets ranged from 71.5%-109.2%, with RSD ranging from 0.6%-15.3%. The combined system, exhibiting satisfying recovery and stable repeatability, can be suitably employed for the simultaneous determination of multiple veterinary antibiotics in animal-derived meat products.