The influence of pH and selected cations on the spectrofluorometric determination of oxytetracycline hydrochloride

Abstract

The spectrofluorometric method for the oxytetracycline hydrochloride in pure and in veterinary products Tetrox and Oxymed 50 determination is described. The influence of pH solution and presence selected cations on fluorescence intensity were studied too. It was ascertained that the highest fluorescence intensity take place at pH=9. Moreover, the quenching of fluorescence intensity was observed at presence Ca2+, Al3+ and Fe3+ in contrast to Mg2+ which caused increasing of intensity. The obtained recovery (97.23±0.12% for Tetrox and 95.21±0.10% for Oxymed 50) values meet the European Pharmacopoeia requirement. Moreover, the relative standard deviation (RSD) was below 0.23% confirmed high precise of the method. The statistical test (t-Student and F-Snedecor) used for comparison spectrofluorometric and chromatographic methods pointed that they are comparable in respect of precision but not of accuracy.