Optimization of the HPLC Method with Postcolumn Derivatization for Determination of Amprolium in Fodders at Contents Lower than 5 mg/kg
Central Institute for Supervising and Testing in Agriculture, Prague and Plzen
An HPLC method was developed and validated for rapid determination of amprolium as an undesirable additive to final fodders. Amprolium is extracted from a sample with a mixture of methanol and dichloromethane and, after purification of the extract on a silica gel column, determined by ion-pair reverse-phase chromatography on C8 with fluorescent detection after postcolumn derivatization with potassium hexacyanoferrate(III) in alkaline medium. The separation of amprolium on the C8 reverse phase and its postcolumn derivatization were optimized. The limit of determination was 86 g.kg-1, the repeatability 0.1 mg/kg and the yield of the method was 102 5.5 % at amprolium concentrations 0.5 - 5 mg/kg.. The repeatability was determined on real samples of final fodders.
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