Simultaneous Determination of Aminoglycoside Residues in Food Animal Muscles by Mixed-Mode Liquid Chromatography-Tandem Mass Spectrometry

A sensitive, selective, and reproducible method was developed for determining nine aminoglycoside antimicrobial residues in swine, cattle, mutton, chicken, and fish muscles by liquid chromatography-tandem mass spectrometry. The analytes were extracted with phosphate buffer solution and purified by a mixed-mode strong cation exchange solid-phase extraction cartridge. Using acetonitrile-1% formic acid solution as a mobile phase system, avoiding the use of the ion pair reagents, the target components retained well and effectively separated on the mixed-mode liquid chromatographic Obelisc R column. It was suggested that the aminoglycoside’s retention time increased with the increase of the number of amino groups in its molecule. The matrix-matched calibration curves for analytes were good linearity within the range of 5–500 μg L−1. The CCαs of analytes were between 2 and 10 μg kg−1, and CCβs were between 6 and 25 μg kg−1. In the spiked levels of 25, 50, and 100 μg kg−1, the average recoveries of analytes were in the range of 65–110% except neomycin of 60–75%, with relative standard deviation below 20%.