[Simultaneous determination of aminoglycoside antibiotics in milk by liquid chromatography with tandem mass spectrometry].
A multiresidue method was developed for determination of nine aminoglycoside antibiotics (streptomycin, dihydrostreptomycin, spectinomycin, neomycin, kanamycin, gentamicin, destomycin A, apramycin, and tobramycin) in milk by LC/MS/MS. The drugs were extracted with 0.01 mol/L potassium dihydrogen phosphate containing 2% trichloroacetic acid, and the extracted solution was cleaned on cation-exchange cartridge columns (Oasis WCX and Oasis MCX). LC separation was performed on a TSK-gel VMpak25 column (50 mmx2.0 mm i.d.) using gradient elution with 0.1% formic acid and acetonitrile containing 0.1% formic acid as the mobile phase. Recoveries of the drugs spiked at 0.01 or 0.1 microg/g in milk ranged from 66.1 to 110.8%, with a coefficient of variation of less than 17.1%. Limits of quantification of the drugs in milk were 0.001 approximately 0.01 microg/g. This method was used for analysis of milk from a lactating cow treated for clinical mastitis with two intramammary infusions of kanamycin (KM). Milk samples were analyzed during the withdrawal times at 12-hour intervals. KM concentrations were lower than the Japanese provisional MRLs (0.4 microg/g) at 60 hours after infusion, and subsequently fell to 0.01 microg/g.
Kajita
Hiroko
H
Research Institute for Environmental Sciences and Public Health of Iwate Prefecture, Iwate, Japan.
Akutsu
Chizuko
C
Hatakeyama
Eriko
E
Komukai
Takashi
T
D000617:Aminoglycosides / Q000032:analysis*; D000818:Animals; D000900:Anti-Bacterial Agents / Q000032:analysis*; D002417:Cattle; D002853:Chromatography, Liquid / Q000379:methods*; D005260:Female; D008892:Milk / Q000737:chemistry*; D053719:Tandem Mass Spectrometry / Q000379:methods*
D000617:Aminoglycosides; D000900:Anti-Bacterial Agents