Determination of methyl benzoquate in poultry feedingstuffs using high-performance liquid chromatography

Abstract

A high-performance liquid chromatographic (HPLC) method for the determination of methyl benzoquate in poultry feedingstuffs is described. Methyl benzoquate is extracted from the feedingstuff with 2% methanesulphonic acid in methanol and the extract partially purified by partition into dichloromethane from hydrochloric acid solution. Major feed interferences are removed by ion-exchange chromatography followed by a second partition into dichloromethane. The methyl benzoquate content of the sample extract is determined by HPLC on an octadecylsilane column. Using this procedure, a mean recovery of greater than 95% was obtained for a range of poultry feeds medicated at 5 and 10 mg kg^–1. For a feed medicated at 1 mg kg^–1 the mean recovery was 93%.