
Keywords: HPLC-ES-MS/MS, high-performance liquid chromatography electrospray ionization tandem mass spectrometry; DO, doxycycline; OFL, ofloxacin; SD/SDZ, sulfadiazine; SMX, sulfamethoxazole; SMZ, sulfadimidine; SP/SPY, sulfapyridine; LOQs, limits of quantification