Kl. Tyczkowska et al., SIMULTANEOUS DETERMINATION OF ENROFLOXACIN AND ITS PRIMARY METABOLITECIPROFLOXACIN IN BOVINE-MILK AND PLASMA BY ION-PAIRING LIQUID-CHROMATOGRAPHY, Journal of chromatography B. Biomedical applications, 658(2), 1994, pp. 341-348
Citations number
12
Categorie Soggetti
Chemistry Analytical
Journal title
Journal of chromatography B. Biomedical applications
A simple and sensitive high-performance liquid chromatographic method
has been developed for the simultaneous determination of enrofloxacin
and ciprofloxacin in bovine milk and plasma. Sample preparation consis
ted of mixing equal volumes of milk or plasma with acetonitrile-0.1 M
sodium hydroxide (1:1, v/v), followed by ultrafiltration through 3000
Da molecular mass cut-off filters. Separation of these two fluoroquino
lones in milk or plasma ultrafiltrate was accomplished by ion-pairing
liquid chromatography using a reversed-phase analytical column eluted
with acetonitrile-methanol-water. Ultraviolet absorbance of the column
effluent was monitored over the 230-350 nm range with a photodiode-ar
ray detector (lambda(max) 278 nm). Recoveries of enrofloxacin from bov
ine milk and plasma were 92-107% and 80-84%, respectively. Recoveries
of ciprofloxacin from bovine milk and plasma were 92-105% and 73-75%,
respectively. The limit of detection for the two compounds was 5 ng/ml
. Enrofloxacin was administered intravenously to a lactating cow at a
dose of 2.5 mg/kg. Enrofloxacin was detected in milk within 15 min aft
er injection and the metabolite ciprofloxacin rapidly appeared in plas
ma and milk. Both enrofloxacin and ciprofloxacin were below the limit
of detection (5 ng/ml) by 48 h after drug administration.