Simultaneous determination of beta-lactam antibiotics in milk by ion-pair liquid chromatography.
A simple and rapid ion-pairing liquid chromatographic method was developed for the simultaneous determination of five penicillins (PCs), ampicillin (AB-PC), benzylpenicillin (PC-G), Dicloxacillin (MDI-PC) and nafcillin (NF-PC) in milk. These PCs are most frequently used for the treatment of mastitis of cows. These antibiotics were extracted with acetonitrile from milk and cleaned up by solid-phase extraction with a C18 cartridge. PCs were separated on a Kaseisorb LC ODS-300-5 column with a mobile phase (1 ml/min) of acetonitrile-methanol-0.05 M potassium dihydrogenphosphate (20:10:80, v/v/v) mixture containing 5 mM of sodium 1-decanesulfonate adjusted to pH 3.5 and UV detection at 210 nm. The average recoveries of five PCs from milk fortified at 0.5 and 1.0 micrograms/ml (n = 5) were 79.8-89.4% with relative standard deviations ranging from 2.7 to 7.2% The detection limit of PCs in milk were 0.03-0.05 microgram/ml.
Takeba
K
K
Tokyo Metropolitan Research Laboratory of Public Health, Japan.
Fujinuma
K
K
Miyazaki
T
T
Nakazawa
H
H
D000818:Animals; D000900:Anti-Bacterial Agents / Q000032:analysis*; D002851:Chromatography, High Pressure Liquid; D002852:Chromatography, Ion Exchange; D007202:Indicators and Reagents; D008892:Milk / Q000737:chemistry*; D010406:Penicillins / Q000032:analysis*; D013056:Spectrophotometry, Ultraviolet; D047090:beta-Lactams
D000900:Anti-Bacterial Agents; D007202:Indicators and Reagents; D010406:Penicillins; D047090:beta-Lactams