Determination of Streptomycin and Dihydrostreptomycin in Meat by Liquid Chromatography/Mass Spectrometry

Abstract

A sensitive and selective method using liquid chromatography-electrospray mass spectrometry (LC-ESI-MS) for the determination of aminoglycoside antibiotics, streptomycin and dihydrostreptomycin, in meat has been developed. The LC separation was performed on a TSK-gel Super ODS column (10 cm×2 mm i.d.) using 5 mmol/L heptafluoro-n-butyric acid (HFBA)-acetonitrile (88 : 12) as the mobile phase at a flow rate of 0.18 mL/min. The positive ionization produced typical [M+H]⁺ molecular ions of both drugs (streptomycin m/z 582; dihydrostreptomycin m/z 584). The calibration graphs for streptomycin and dihydrostreptomycin were rectilinear from 0.25 to 25 ng with selected ion monitoring (SIM). The drugs were extracted with 1% metaphosphoric acid, and the extracts were added to 2 mL of 0.1 mol/L heptanesulfonic acid. The solution was cleaned up on a Bond Elut C18 (500 mg) cartridge. The recoveries of streptomycin and dihydrostreptomycin from swine and bovine muscle fortified at 0.2 μg/g were 73.2∼82.6%, and the detection limits were 0.01 μg/g for both drugs.