Screening for the coccidiostats halofuginone and nicarbazin in egg and chicken muscle: development of an ELISA.

摘要

Nicarbazin and halofuginone have been widely used as coccidiostats for the prevention and treatment of coccidiosis in poultry. It has been shown that accidental cross-contamination of feed can lead to residues of these compounds in eggs and/or muscle. This paper describes a direct competitive assay for detecting halofuginone and nicarbazin, developed as qualitative screening assay. In an optimized competitive ELISA, antibodies showed 50% binding inhibition at approximately 0.08 ng/ml for halofuginone and 2.5 ng/ml for dinitrocarbanilide (marker residue for nicarbazin). Extraction from the matrix was carried out with acetonitrile followed by a wash with hexane. The assay's detection capability (CC beta ) for halofuginone was <0.5 micro g/kg in egg and <1 micro g/kg in muscle. For dinitrocarbanilide, the CC beta was estimated at <3 micro g/kg in egg and <10 micro g/kg in chicken muscle.