Comparison of microbiological plate-four level assay and liquid chromatography analysis for the determination of amoxicillin in medicated feedingstuff

The experiment was purposed to compare amoxicillin determination in medicated feedingstuff by a microbiological method (microbiological plate-four level test) and a liquid chromatography with fluorescence detection (LC- FLD) with pre-column derivatisation with formaldehyde. Amoxicillin was determined in the medicated feedingstuff at the level of 250 mg/kg. The results indicated that the microbiological method might provide adequate data suitable for amoxicillin determination in the medicated feedingstuff. These results were confirmed by the LC method. Therefore, for practical use, the values obtained with two methods can be considered equivalent.