This paper reported the research on the simultaneous separation and determination of six
cephalosporins by RP\|HPLC. Six
cephalosporins are cefalcor ,cefalexin, cefradine,
cefadroxil, cefominox and cefoxitin .The analytical conditions for this method were as follows: a Hypersil ODS C 18 (200 mm×4.6 mm i.d., 5 μm), detection wavelength: 254 nm; a mobile phase solution of 50 mmol/L monopotassium phosphate (pH 3.4)\|acetonitrile(87.5∶12.5) and DAD detector. The flow rate was 1.0 mL/min. The calibration curves of the six compounds were linear, the correlation coefficients were 0.995 1 for cefominox, 0.999 9 for the others ,the range were 164 ng\|16.4 μg for cefominox, 99 ng\|9.934 μg for cefadroxil, 104 ng\|10.358 μg for cefalcor, 122 ng\|12.224 μg for cefalexin, 107 ng\|10.702 μg for cefradine and 115 ng\|11.506 μg for cefoxitin. The recovery rates were 103.5% for cefominox,99.3% for cefadroxil,101.4% for cefalcor,101.5% for cefalexin,98.7% for cefradine and 97.6% for cefoxitin . Six
cephalosporins were all stable in 50 mmol/L monopotassium phosphate (pH 3 4\|4 6).When preparations of these cephalosporins were determined, it is indicated there were no difference between the results by using this method and the pharmacopoeia methods .The total separation time of these cephalosporins was within fifteen minutes. This method is simple, sensitive, rapid and accurate.