In this experiment, a novel solid phase extraction (SPE) device, the Oasis PRiME HLB Cartridge, was used in the sample preparation of milk samples as a cleanup method for multi-residue veterinary drug analysis. The initial extraction and protein precipitation was done by adding acidified acetonitrile. The extract was cleaned up by pass-thru SPE using the Oasis PRiME HLB Cartridge prior to UPLC-MS/MS analysis. Sample extraction, chromatographic and mass parameters were all optimized.
As a result, within the ranges of 0.1 to 10.0 μg/mL spiking concentrations, 9 classes of 72 veterinary drugs including sulfonamides, fluoroquinolones, β-agonists, macrolides, glucocorticoids, amphenicols, β-lactams, cephalosporins, penicillin, and tetracyclines, the percent recoveries are all within 50% to 130%, and the RSD <20% (n=5). This method is simple, rapid, and accurate, suitable for multi-residue veterinary drug analysis of milk.