High-throughput method for the determination of nitroimidazoles in muscle samples by liquid chromatography coupled to mass spectrometry

We present a high-throughput confirmatory method for the analysis of 11 nitroimidazoles in muscle samples (metronidazole, MNZ; dimetridazole, DMZ; ronidazole, RNZ; tinidazole, TNZ; carnidazole, CRZ; secnidazole semihydrate, SCZ; ornidazole, ORZ; metronidazole-hydroxy, MNZ-OH; ipronidazole, IPZ; ipronidazole-hydroxy, IPZ-OH; and dimetridazole-hydroxy, HMMNI). Extraction with acetonitrile is efficient and simple, with the majority of recoveries ranging between 65 and 101 %, and without the need for clean-up of the extracts. The chromatographic analysis is performed using UPLC-QqQ-MS in the MRM mode, with an electrospray source operated in positive mode. Total chromatographic analysis time is 12 min. This method has been fully validated in muscle according to Decision 657/2002/CE guidelines, and the CC alpha values obtained were in the range of 0.04-0.4 mu g center dot kg(-1). The method is currently used for the analysis of muscle samples and has been tested in other matrices of animal origin, such as kidney, retina and egg, with excellent results.