Determination of 11 aminoglycosides residues in dairy products by liquid chromatography tandem mass spectrometry after immunoaffinity SPE

ObjectiveTo establish a method for simultaneous determination of 11 aminoglycosides antibiotics （spectinomycin， dihydrostreptomycin， hygromycin B， streptomycin， gentamicin C1， amikacin， gentamicin C2， kanamycin， gentamicin C1a， tobramycin and apramycin） in liquid milk and milk powder samples by high performance liquid chromatography tandem mass spectrometry （HPLC­MS/MS）.MethodsThe dairy products were extracted by water containing 1% acetic acid， concentrated and purified by the immunoaffinity cartridges， and then analyzed by HPLC­MS/MS. A BEH Amide column was used for the separation of target drugs as well as acetonitrile and water containing 0.5% formic aid used as the mobile phase. Matrix matched calibration was applied in the quantitation.ResultsThe calibration curves achieved good linearity in the range of 5­500 μg/L with the correlation coefficients （r） greater than 0.99； the quantification limits of AGs in liquid milk and powder were 3 and 10 μg/kg， respectively. The average recovery ranged from 65.12% to 105.95% with relative standard deviations （RSD） ranged from 0.85% to 19.12%.ConclusionThis method presented good selectivity， high sensitivity and simple operation， which was suitable for the determination of 11 aminoglycoside antibiotics in dairy products.