In this study,the simple,sensitive,stable and reliable analysis methods were established to detect ten aminoglycosides in feeds and environmental water,respectively.The ten aminoglycosides in feeds were simultaneously determined by high performance liquid chromatography-evaporative light scattering detection?HPLC-ELSD?.The feed samples were extracted with phosphate buffer?containing 0.4 mmol/L ethylenediaminetetraacetic acid and 2%trichloroacetic acid aqueous solutions?and were purified by MCX solid phase extraction c artridge.The residues were re-dissolved with 1mL 20 mmol/L heptafluorobutyric acid solution.The extracts were injected directly into the HPLC-ELSD system after passed through a 0.22?m filter.The acetonitrile/20 mmol/L heptafluorobutyric acid solution?5:95,v/v?and acetonitrile/20 mmol/L heptafluorobutyric acid solution?50:50,v/v?were chosen as mobile phases.Target compounds were separated well on Hypersil BDS C18 column?250 mm×4.6 mm i.d.,5?m?by following the optimized gradient elution program.Analytes were quantified using the matrix-matched external calibration curves.The results showed that the calibration curves of eight aminoglycosides were good linearity in the experimental concentration range,with correlation coefficients?r2?higher than 0.99.In three spiked levels of 1?1.5 or 2?,10,20 mg/kg for blank feed samples,recoveries of target compounds were between 61.2%and 104.0%with coefficients of variance below 15%.The limits of detection?LODs?and limits of quantification?LOQs?of analytes ranged from 0.2 to 0.7 mg/kg and 1.0 to 2.0 mg/kg,respectively.The ten aminoglycosides residues in environmental water sample were simultaneously determined by liquid chromatography-tandem mass spectrometry?LC-MS/MS?.Water samples were lyophilized and re-dissolved with 2 mL of 2%acetic acid prior to LC-MS/MS system.Target compounds were separated well on SIELC Obelisc R?2.1 mm×150 mm i.d.,5?m?using the 1%formic acid and acetonitrile as mobile phase,and determined by LC-MS/MS operating in positive electrospray ionization mode.Analytes were quantified using the matrix-matched calibration curves.The results indicated that the calibration curves of ten aminoglycosides showed good linearity within the experimental concentration range,with correlation coefficients?r2?higher than 0.99.In the three spiked concentrations of 10,20 and 50?g/L,the average recoveries of ten analytes ranged from 65.8%to 115.7%with coefficients of variance below 20%.The LODs and LOQs were in range of 1.0 to 12.0?g/L and 2.0 to 20.0?g/L,respectively.The method was successfully applied to the determination of aminoglycosides in environmental water samples. |