Study on fluorescence of the Tb(iii)–enoxacin system and the determination of enoxacin

Abstract

A very simple, rapid and highly sensitive fluorimetric method for the determination of enoxacin (ENX) is described. The method is based on the formation of Tb(III)–ENX complex in the aqueous solution, which fluoresces intensely with an emission maximum at 545 nm (Tb³⁺∶⁵D₄ → ⁷F₅) when excited at 335 nm. Optimum conditions for the determination were investigated. A linear relationship was obtained between the fluorescence intensity and ENX concentration in the range 8.0 × 10^–9–6.0 × 10^–6 M. The limit of detection was 5.9 × 10^–10 M. Analytical recoveries from untreated urine samples spiked with ENX were in the range 95–102.5%.