EN
A method for the identification and determination of ionophorous coccidiostatics such as monensin, salinomycin, narasin and lasalocid in feedingstuffs has been described. The method is based on the reaction of these compounds with an alcoholic vanillin solution. Separation and identification of the ionophores by means of the thin layer chromatography permits to detect monensin, salinomycin and narasin in the amounts of 5 mg/kg and lasalocid by 10 mg/kg feedingstuffs. Quantitative determinations are performed by the colorimetric method at 518 nm. The method makes possible to detect monensin, salinomycin and narasin at the content of 1.0 mg/kg feedingstuffs. However, this method is not applicable for lasalocid.