Multi-residue analysis of traces of pesticides and antibiotics in honey by HPLC-MS-MS

The aim of this work was to develop an analytical method for simultaneous assay of residues of two families of antibiotics, and three pesticides, in honey. The assays involved a mixture of five tetracyclines, four sulfamides, and the pesticides coumaphos, carbendazim, and amitraz (two metabolites). All the compounds were extracted from honey and pre-concentrated by optimised solid-phase extraction (SPE). Analysis was by high-performance liquid chromatography-mass spectrometry-mass spectrometry (HPLC-MS-MS) using a triple-quadrupole spectrometer in multiple reaction monitoring (MRM) mode in order to identify and quantify the compounds present (Sheth et al J Agric Food Chem 38:1125–1130, 1990). During development of the analytical method a strong matrix effect was found that depended on the floral origin of the honey. This led to the development of a standard additions method to quantify the contaminants sought.