The Resonance Rayleigh Scattering Spectrum Characteristic of Tb3+-GMFX-AR and the Determination of Gemifloxacin
A new method for the determination of Gemifloxacin (GMFX) by using Resonance Rayleigh scattering was put forward. In HAc-NaAc buffer solution of pH 5 - 6, terbium (III) and antibiotics GMFX could form cationic complexes, which coulf further form 1 :2 : 1 (Tb3+ : GMFX :AR) ternary ion association complexes by the reaction with Alizarin Red (AR) anion through electrostatic and hydrophobic interaction. The new Resonance Rayleigh scattering (RRS) spectra would appear, and the two scattering peaks were located at 370nm and 590 nm. At 370 nm, the scattering enhancement (ΔI) was proportional to GMFX of certain concentration and its linear range and detection limit (3σ) were 0.005 ~ 4.00 μg.mL-1and 14.5 ng.mL-1. This method is simple, fast, with good selectivity and reproducibility, and it can be used for determination of GMFX drug in various body fluids.