1. Sulfadiazine, 2. sulfamerazine, 3. sulfametoxydiazine, 4. sarafloxacin; blank pork muscle spiked with 50 μg.kg-1 for each analyte; 2 times to each pork sample, and the chromatographic measurement carried out 3 times; recovery data are the average value of three measurements and contains less than 2% of relative standard deviation.
