A micellar capillary electrophoresis（MCE） method based on on-line sweeping technique was（developed） for a determination of trace quinolones,ciprofloxacin ofloxacin and enrofloxacin in pork tissue.The pork tissue samples were deproteinized with trichloroacetic acid and in the running buffer of 20 mmol/L（Na2B4O7）+80 mmol/L sodium dodecyl sulfate（SDS）,pH=9.6,the ciprofloxacin,ofloxacin and enrofloxacin in the sample were successfully separated and detected within 200 s,in a non-coating fused-silica capillary column（48.5 cm×75 μm i.d.,effective length 40 cm） at separation voltage of 18 kV,and the injection pressure of 15×10～2 Pa,with UV detection at 278 nm.The detection limits of ciprofloxacin,ofloxacin and enrofloxacin were 0.007,0.016 and 0.020 mg/L,and RSD were 2.0%,2.4% and 2.6%,respectively.This method allows of up to 600-fold accumulation concentration of ciprofloxacin and can be used to separate and detect the residuals of trace medicines in animal food.
