Identification of transformation products of pesticides and veterinary drugs in food and related matrices: use of retrospective analysis.

Retrospective analysis has been applied in different samples, including honey, meat, feed and nutraceutical products from ginkgo biloba, soya, royal jelly and green tea, with the aim of searching transformation products of pesticides and veterinary drugs, which were not included in an initial analysis. Generic extraction and analytical procedures based on high resolution mass spectrometry (Exactive-Orbitrap analyser was used) have been applied. All obtained data have been reprocessed and some compounds as anhydroerythromycin in honey and 3,5,6-trichloro-2-pyridinol in feed have been detected, demonstrating the applicability and the utility of the procedure. Advantages and disadvantages of retrospective approach have been highlighted.