Collaborative study of a method for the determination of residues of halofuginone in chicken tissue

Abstract

A procedure is described for the determination of halofuginone residues in chicken tissues. The halofuginone is extracted as the free base with ethyl acetate after digestion of the tissues with trypsin and then partitioned into an aqueous ammonium acetate buffer. After further clean-up and concentration using a Sep-Pak C₁₈ cartridge, the extract is examined by high-performance liquid chromatography using a reversed-phase column and a UV detector. The procedure was tested by carrying out procedural recoveries from spiked samples and also by a collaborative exercise using samples of tissues from birds fed on a diet containing halofuginone. The efficiency of the extraction procedure was assessed by using samples of a chicken that had been fed with ¹⁴C-labelled halofuginone.