Development of a detection method for fluoroquinolone antibiotics using flow injection analysis with electrochemiluminescent detection

CHED 295

Heeyoung Wang, wang369@creighton.edu, Matthew Burkhead, msb38308@creighton.edu, and Erin Gross, eringross@creighton.edu. Department of Chemistry, Creighton University, 2500 California Plaza, Omaha, NE 68178
A flow injection analysis (FIA) method was developed for the electrochemiluminescent (ECL) detection of fluoroquinolone antibiotics. Tris (2,2'-bipyridyl) ruthenium (II) (Rubipy) was used as the chemiluminescent reagent. A homemade platinum cylinder working electrode (1mm diameter) was used in the flow cell for light generation. The flow rate was optimized at 1 mL/min and the potential for maximum light generation was determined to be 1.2 V. Experiments were performed to determine the optimum solution conditions for the ECL reaction. The conditions studied included Rubipy concentration, pH, and added methanol percentage. Detection and quantification limits were then determined experimentally by holding Rubipy concentration at 2 mM while varying the enrofloxacin concentration. Using a pH 7 phosphate buffer, the limit of detection was determined to be 100 nM enrofloxacin and the limit of quantification to be 300 nM enrofloxacin.