Determination of aminophylline residues in edible tissues of pig by high performance liquid chromatography tandem mass spectrometry

Objective: A method for the determination of aminophylline residues in edible tissues （muscle, liver and kidney） of pigs by solid-phase extraction combined with high performance liquid chromatography-tandem mass spectrometry was established. Methods: After extracted by methanol, the aminophylline was purified by PRiME HLB solid phase extraction column in one step, and then separated by a C18 chromatographic column. 0.1% formic acid solution and acetonitrile were invoked as the aqueous phase and the organic phase for gradient elution, respectively. Electrospray positive voltage ionization and multi reaction monitoring （MRM） mode are used for compound detection, and matrix matching standard was used for quantification. Results: The analysis of aminophylline drugs was completed within 3.5 minutes, and the results showed good linear relationship （R＞0.998 0） on different matrices in the concentration range of 0.05~1.0 μg/mL. The average recoveries ranged from 87.2% to 101.3%, and the relative standard deviations ranged from 0.7% to 6.2% （n=6）. The detection limit was 2 μg/kg and the quantification limit was 5 μg/kg. Conclusion: The method which is simple and efficient, has good repeatability and high sensitivity. It is suitable for qualitative and quantitative analysis of aminophylline drug residues in edible tissues of pigs.