Optimisation of Europium Sensitized Fluorescence Assay for Detection of Tetracycline Antibiotics
Objective: Europium sensitized fluorescence method for tetracycline antibiotics determination in various samples was optimized. Method: The factors that influence intensity of the europium–tetracycline fluorescence have been studied in detail. Fluorescence intensity measurement was carried out using Shimadzu RF-5301-PC spectrofluorometer (Kyoto, Japan) with Panorama fluorescence 1.1 software. Results: The parameters that can affect the fluorescence of europium-tetracycline complex are optimized. Best results were obtained using tris buffer and 1 mm of citric acid as co ligands. The method is linear in the range of 5-2500 ng/ml for tetracycline and oxytetracycline and 5-1000 ng/ml for chlortetracycline and can be used for their determination in various samples. Conclusion: Europium–tetracycline sensitized fluorescence is a very sensitive that can be used for determination very low tetracycline concentrations. It is necessary to optimize all parameters that can affect the fluorescence, in order to achieve low detection limits.