OBJECTIVE A new capillary zone electrophoretic method has been established for the rapid determination of cefadroxil and
trimethoprim in plasma.METHODS The analysis was performed in an uncoated fsedsilica capillary with 75μm(i.d).And total length socm with a buffer solution of 20mmol/L disodium tetraborate(pH7.5).The applied voltage was 20kV and UV detection wavelength was 267nm,internal calibration curve of peak area was selected. RESULTS The linear range of cefadroxil and
trimethoprim were0.4～4.0μg/mL,0.25～4.0μg/mL,
respectively.The recoveries obtained from plasma for the two medicine were more than 97%.The intra-day and inter-day presision assessed at three mass concentration levels were satisfactory.The relative standard deviation(RSD) value for migration time of cefadroxil and trimethoprim were 1.23% and 2.41%,respectively;the RSD value for peak area was 2.23% and 1.60%.CONCLUSION The method is less solvent consumption,simple,rapid and accurate,and it can be applied to the research biological equivalent.