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

Abstract A liquid chromatographic-mass spectrometry (LC-MS/MS) method for the determination of streptomycin (STR) and dihydrostreptomycin (DHS) sulfate in milk and meat is described. Samples of milk and meat were homogenized with an extraction solution of ammonium acetate/hydrochloric acid/trifluoroacetic acid and centrifuged. The supernatant was filtered, diluted, and injected into the LC-MS/MS. The recovery of STR and DHS from milk varied from 79 to 83%. The recovery of STR and DHS from meat varied from 84 to 90%. The limits of quantification for both milk and meat were 50 ng/mL (g) for STR and 35 ng/mL (g) for DHS.