Thin-layer chromatography/bioautography method for detection of monensin in poultry tissues

Monensin is an effective anticoccidial agent widely used in the poultry industry. Because of concerns over its toxicity, a sensitive, reliable, fast, and simple method for residue detection in poultry tissues is desirable from both a diagnostic and a regulatory view. Many methods of detection are excluded due to this ionophore's complex chemical and biological nature. A common method used for its detection is thin-layer chromatography/bioautography (TLC/B), although this is usually only semiquantitative. A new TLC/B method for monensin detection in poultry tissues was developed and is reported here. Recovery from cardiac muscle, skeletal muscle, and liver and kidney tissues is in the range of 93-97%. A detection limit of 250 micrograms/kg with 99% reliability was achieved with this method. Lower limits (to 10 micrograms/kg) were detectable, but with lower reliability (60%). Quantitative analysis is not possible on samples from fatty tissue.