Development and validation of a method for the confirmation of halofuginone in chicken liver and eggs using electrospray tandem mass spectrometry

A method is described for the quantitative confirmation of halofuginone (HFG) residues in chicken liver and eggs. This method is based on LC coupled to positive ion electrospray MS–MS of the tissue extracts, prepared by trypsin digestion of the tissues followed by liquid–liquid extraction and final clean-up using Solid Phase Extraction (SPE). The [M+H]+ ion at m/z 416 is monitored along with four transitions at m/z 398, 138, 120 and 100. The method has been validated according to the draft EU criteria for the analysis of veterinary drug residues at 15, 30 and 45 μg kg−1 in liver and 5, 15 and 50 μg kg−1 in eggs. The new analytical limits, CCα and CCβ were calculated for liver and were 35.4 and 43.6 μg kg−1, respectively.