Nitroimidazoles in turkey muscle-the influence of sampling conditions on measurement results in residue control

Nitroimidazoles in incurred muscle samples showed a considerable inhomogeneity in their distribution. A possible explanation for this phenomenon were the sampling conditions. In an animal study, the influence of sampling after slaughtering was investigated by applying four different ways of treating muscle samples prior to freezing at −24 °C. The muscle samples were analysed using gas chromatography-negative chemical ionisation/mass spectrometry after silylation. The results reaffirmed an inhomogeneous distribution of ipronidazole and ronidazole in muscle samples, irrespective of the sampling procedure. Thermal stress caused a significant loss of analytes, even at +4 °C.