Abstract
An HPLC method is described which enables the qualitative and quantitative analysis of residues of pharmacologically active substances in food stuffs of animal origin. Egg samples were spiked with the therapeutic drugs sulfapyridine and its N-acetyl metabolite, with ethopabat, chloramphenicol, meticlorpindol, metronidazol, ipronidazol, furazolidone and nicarbazin and with pyrazon and benzothiazuron as internal standards in the range of 0.02 to 0.1 mg/kg. The drugs were extracted with acetonitrile and purified by liquid-liquid partition steps. They were separated on a reversed phase column and detected with a multi-signal UV/Vis diode-array detector at 3 different wavelengths: 275, 315 and 360 nm. The peak's identity was confirmed by comparing retention times and UV spectra with those of standards. Peaks were checked for homogenity by comparing spectra at the peak's upslope, apex and downslope. The detection limit was in the range of 0.001 to 0.05 mg/kg.