Spectrofluorimetric detection of bacitracin in various water samples based on the formation of yellow fluorescent nitrobenzofurazan derivative

Abstract

Bacitracin is one of a group of antibiotic growth promoters that has been prohibited in the European Union. Its effectiveness is limited to a certain range of Gram–positive bacteria. In this study, a newly validated spectrofluorimetric approach was used to detect bacitracin in different types of water samples. The suggested spectrofluorimetric technique relied on the formation of a yellow fluorescence reaction product upon the interaction between BCT in a buffered solution at alkaline pH and 4-Chloro-7-nitrobenzofurazan reagent. The yielded reaction product has an excitation of 473.4 nm and a yellow fluorescence emission of 540 nm. To achieve maximum sensitivity and robust results, variables of the experiment such as pH, volume of derivatizing reagent, amount and type of buffer, diluting solvent, temperature of the reaction and heating time, post-reaction acidification, and stability time were examined and improved. In addition, the method exhibited a linear range of 0.5–3.0 µg/mL and an LOD value of 0.095 µg/mL. Additionally, the selectivity of the method against common antibiotics and metal ions was studied and evaluated. Moreover, the method was successfully applied to detect BTC in various water samples. Finally, the validated approach could possibly be employed in quality control laboratories for regular BCT analysis.