Quantification of Nitroimidazoles Residues in Swine Liver by Liquid Chromatography-Mass Spectrometry with Atmospheric Pressure Chemical Ionization

A liquid chromatography-mass spectrometry method was developed for the simultaneous determination of ronidazole (RNZ), metronidazole (MNZ) and dimetridazole (DMZ) residues in swine liver. Following liquid-liquid extraction, the HLB solid-phase extraction was used for further purification. The targets were detected by atmospheric pressure chemical ionization (APCI) following the reverse phase liquid chromatography separation. Consequently, the detection limits for the method were 0.5 mu g/kg for MNZ, 1.0 mu g/kg for RNZ and 0.5 mu g/kg for DMZ, respectively. The accuracies were determined using swine liver samples fortified at levels of 0.5, 1, 2, and 4 mu g/kg and the mean recoveries of the analytes were between 66% and 81%.