Abstract: A high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) analytical method was developed for the simultaneous determination of ten aminoglycoside residues (streptomycin, dihydrostrepmycin, neomycin, kanamycin, tobramycin, gentamycin, apramycin, hygromycin B, paromomycin, and amkacin) in milk and dairy products. The sample was extracted with 5% trichloroacetic acid aqueous solution, then the extract was purified by a hydrophilic-lipophilic balance (HLB) cartridge. The ten aminoglycoside residues were separated by ion-pair reversed phase high performance liquid chromatography. Heptafluorobutyric acid was used as ion pair agent due to its volatility. Then the analytes were detected by electrospray ionization tandem mass spectrometry. The pretreatment condition of the sample, the HPLC condition and the MS operation parameters were optimized. The results showed that the linearities of the ten aminoglycoside residues in 20~1000 μg/L had the correlation coefficient between 0.9946~0.9997. The recoveries ranged from 71.2% and 101.7% with the relative standard deviations of 3.4%~13.8%. The proposed method was successfully applied to the determination of the mass concentrations of the analytes in related samples, which provides a simple, and convenient method for the quality control of milk and dairy products. Furthermore, this method is effective for the safety monitoring of aminoglycoside residues in milk and dairy products.

Key words: aminoglycosides, hydrophilic-lipophilic balance (HLB) cartridge, milk and dairy products, high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS)