[Detection of residual antibiotics in honey with capillary electrophoresis]

Five antibiotics compounds, tetracycline (TC), oxytetracycline (OTC), doxycycline (DOC), chlortetracycline (CTC) and chloramphenicol (CP), were successfully separated and determined by high performance capillary electrophoresis(HPCE). Effects of buffer pH, various organic additives and temperature on electrophoretic separation of antibiotics were investigated. Satisfactory separation of these five antibiotics was achieved in the buffer of pH 3.2, 0.02 mol/L Na2HPO4-0.01 mol/L citric acid with addition of 4% (V/V) N-methylmorpholine and 12% (V/V) acetonitrile within 20 minutes. The calibration graphs were linear by plotting the peak area against the sample concentration over the range of 150 micrograms/L to 750 micrograms/L and the correlation coefficients were greater than 0.9917. The detection limits were 10 micrograms/L for CP, 20 micrograms/L for TC, OTC and DOC and 40 micrograms/L for CP (signal to noise ratio > 5). HPCE method was successfully applied to the analysis of trace antibiotics in honey.