Chemiluminescence determination of some fluoroquinolone derivatives in pharmaceutical formulations and biological fluids using [Ru(bipy) 32+]–Ce(IV) system

A new chemiluminescence (CL) method using flow injection has been described for the rapid and sensitive determination of three fluoroquinolone derivatives, namely ofloxacin, norfloxacin and ciprofloxacin hydrochloride. The method is based on the CL reaction of the studied fluoroquinolones with tris(2,2′-bipyridyl)ruthenium(II) [Ru(bipy) 3 2+] and Ce(IV) in sulfuric acid medium. Under the optimum conditions, the CL intensity is proportional to the concentration of the drugs in solution over the range 0.05–7.0 μg ml −1 for norfloxacin, 0.05–6.0 μg ml −1 for ciprofloxacin hydrochloride and 0.003–0.7 μg ml −1 for ofloxacin. The limits of detection ( s/ n=3) were 3.1×10 −8 M norfloxacin, 2.6×10 −8 M ciprofloxacin hydrochloride and 5.5×10 −9 M ofloxacin. The method was applied successfully to the determination of these compounds in dosage forms and biological fluids.