A method was established for the determination of streptomycin(STR) and dihydrostreptomycin(DHS) in vegetable foods(apple

celery

capsicum and lentil) based on high performance liquid chromatography-tandem mass spectrometry(HPLC-MS/MS).The sample was extracted with phosphate buffer and cleaned up with a WCX solid phase extraction cartridge.The extracts were separated on an Atlantis Hilic Silica column(100 mm×30 mm

3 μm) using acetonitrile-01 mol/L ammonium formate and 01% formic acid as mobile phases by isocratic elution

then detected by HPLC-MS/MS in positive ion mode under multiple reaction monitoring(MRM) mode.An external standard method was used for quantitative analysis.The calibration curves for streptomycin and dihydrostreptomycin showed good linearity in the range of 10-120 μg/L with their correlation coefficients(r) more than 0999.The limits of quantitation(LOQs) were both 125 μg/kg.The average recoveries for streptomycin and dihydrostreptomycin at three spiked levels of 125

250 and 500 μg/kg ranged from 836% to 101%

with the relative standard deviations(RSDs) of 23%-76%.With no need of ion pair reagents resulting in the contamination of liquid chromatography-mass spectrometer

the method is simple

rapid

reliable and stable

and could meet the requirements for determination of streptomycin and dihydrostreptomycin residues in most vegetative samples.