Determination of ofloxacin using a highly selective photo probe based on the enhancement of the luminescence intensity of Eu3+--ofloxacin complex in pharmaceutical and serum samples.

A rapid, simple and sensitive spectrofluorimetric method for determination of trace amount of ofloxacin was developed. At pH 5.1 the ofloxacin enhances the luminescence intensity of the Eu(3+) ion in Eu(3+)- ofloxacin complex at λ(ex) = 365 nm. The produced luminescence intensity of Eu(3+)-ofloxacin complex was in proportional to the concentration of ofloxacin. The working range for the determination of ofloxacin was 5.0 × 10(-9)-5.0 × 10(-6) mol L(-1) with lower detection limit (LOD) and quantitative detection limit (QDL) of 3 × 10(-9) and 9 × 10(-9) mol L(-1), respectively. The enhancement mechanism of the luminescence intensity in the Eu(3+)-ofloxacin system has been also explained. The method revealed good selectivity for ofloxacin in the presence of coexisting substances and used successfully for the assay of ofloxacin in pharmaceutical preparations and serum. A comparison with other standard methods was also discussed.