title: Study on the interaction between fluoroquinolones and erythrosine by absorption, fluorescence and resonance Rayleigh scattering spectra and their application.
abstract: In pH 4.4-4.5 Britton-Robinson (BR) buffer solution, fluoroquinolone antibiotics (FLQs) including ciprofloxacin (CIP), norfloxacin (NOR), levofloxacin (LEV) and lomefloxacin (LOM) could react with erythrosine (Ery) to form 1:1 ion-association complexes, which not only resulted in the changes of the absorption spectra and the quenching of fluorescence, but also resulted in the great enhancement of resonance Rayleigh scattering (RRS). These offered some indications of the determination of fluoroquinolone antibiotics by spectrophotometric, fluorescence and resonance Rayleigh scattering methods. The detection limits for fluoroquinolone antibiotics were in the range of 0.097-0.265 microg/mL for absorption methods, 0.022-0.100 microg/mL for fluorophotometry and 0.014-0.027 microg/mL for RRS method, respectively. Among them, the RRS method had the highest sensitivity. In this work, the spectral characteristics of the absorption, fluorescence and RRS, the optimum conditions of the reactions and the properties of the analytical chemistry were investigated. The methods have been successfully applied to determination of some fluoroquinolone antibiotics in human urine samples and tablets. Taking CIP-Ery system as an example, the charge distribution, the enthalpy of formation and the mean polarizability were calculated by density function theory (DFT) method. In addition, the reasons for the enhancement of scattering spectra were discussed.
authors.affiliation: School of Chemistry and Chemical Engineering, Southwest China University, Chongqing 400715, People's Republic of China.
authors.forename: Jian
authors.initials: J
authors.lastname: Wang
authors.forename: Zhongfang
authors.initials: Z
authors.lastname: Liu
authors.forename: Jiangtao
authors.initials: J
authors.lastname: Liu
authors.forename: Shaopu
authors.initials: S
authors.lastname: Liu
authors.forename: Wei
authors.initials: W
authors.lastname: Shen
mesh_terms: D000042:Absorption; D002939:Ciprofloxacin / Q000652:urine; D004923:Erythrosine / Q000737:chemistry*; D024841:Fluoroquinolones / Q000737:chemistry*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008968:Molecular Conformation; D009994:Osmolar Concentration; D012542:Scattering, Radiation; D013050:Spectrometry, Fluorescence
chemical_list: D024841:Fluoroquinolones; D002939:Ciprofloxacin; D004923:Erythrosine