Simultaneous Determination of Aminoglycoside Residues in Environmental Water Matrices by Lyophilization Combined with Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS)

A simple, reliable and environmentally friendly pretreatment method for the simultaneous determination of ten aminoglycoside residues in environmental water samples was established by lyophilization combined with liquid chromatography-tandem mass spectrometry (LC-MS/MS). The water samples were lyophilized to dryness and reconstituted in 2% aqueous acetic acid. The target compounds were separated on a mixed-mode Obelisc R column using1% formic acid and acetonitrile as the mobile phase and determined by LC-MS/MS operating in the positive electrospray ionization mode. The analytes were quantified using matrix-matched calibration curves. The results indicated that the calibration curves of ten aminoglycosides showed good linearity within the experimental concentration ranges with correlation coefficients (r(2)) higher than 0.99. For the three spiked concentration levels of 10, 20, and 50 mu g L-1, the average recoveries of ten analytes ranged from 65.8% to 115.7% with relative standard deviations less than 20%. The limits of detection and quantification were in ranges from 1 to 12 mu g L-1 and 2 to 20 mu g L-1, respectively. The developed method was successfully applied to the determination of ten aminoglycoside residues in pond water collected from local livestock farms in different regions of Guangdong Province.