Study And Application Of Fluorescence Characteristics Of Rare Earth Ions Interaction With Antibiotics

Common analysis methods of antibiotics includes high performance liquidchromatography(HPLC),electrochemical analysis, thin layer chromatography, fluorescenceanalysis, etc. Fluorescence analysis is widely used in the analysis of the antibioticmedicines because of low detection limit, high sensitivity, easy operation etc. Because onlythe drug with special structure of benzene ring have luminescence properties, fluorescenceis also easily subject to background interference of Raman peaks and scattered light, so afew kinds of drugs can be used direct fluorescence analysis. Accordingly,the improvedfluorescence analysis technology appear constantly.Rare earth fluorescent probe has manyadvantages of large stokes shift, linear emission spectra, long fluorescent lifeetc.Fluorescence quenching with high sensitivity and selectivity is better than directfluorescence analysis.These two kinds of indirect fluorescence methods expand the scopeof antibiotic drug analysis.The traditional analysis method of Quinolones including Nadifloxacin, Levofloxacinand Cephalosporin including Ceftriaxone is HPLC.In this paper, using Eu3+and Ce3+formcomplexes with the three kinds of antibiotics, thus three new methods of fluorescenceanalysis methods have been established.Nadifloxacin (NDFX) can form complexes with Eu3+,which has characteristicfluorescence peak of Eu3+at594nm and618nm.Surfactant SDBS can sensitizefluorescence intensity of Eu3+-NDFX system, thus the Eu3+-NDFX-SDBS fluorescentprobe system has been established. In this paper, several influencing factors have beenstudied including pH, Eu3+concentration, reaction time and interfering substances,so thatthe best determination conditions were determined.Using this method of NDFX ointmentcontent and recovery rate were determined, the average recovery rate could be over97%.The redshift of excitation spectra shows that the system formed Eu3+-NDFX binarycomplexes.The change of the surface tension of SDBS shows that it formed stabile micellein the system,which has played an important role in the solubilization and sensitization. Equal mole continuous variation method determine the ligand ratio of complexes of NDFXand Eu3+is2:1.Ce3+and levofloxacin (LVFX) both have strong fluorescence peak. The emissionwavelength of Ce3+and excitation wavelength of LVFX has a part of overlap.,thus LVFXhas energy transfer quenching effect on the Ce3+，which in turn Ce3+also has quenchingeffect on the LVFX, thus Ce3+fluorescence quenching LVFX system has been established.In this paper, several influencing factors have been studied including pH, reaction time andsurfactant, so that the best determination conditions were determined.Using this method ofLVFX injection content and recovery rate were determined, the average recovery ratecould be over96%.The linear range of LVFX energy transfer quenching Ce3+is relativelynarrow.Excitation spectrum of LVFX shows that Ce3+quenching of LVFX type belongs todynamic quenching.Ceftriaxone (CRO) and Ce3+can form complexes, CRO has obvious quenching effecton Ce3+,thus CRO fluorescence quenching Ce3+system has been established.In this paper,several influencing factorshave been studied including Ce3+concentration, pH,reaction timeand interfering substances,so that the best determination conditions were determined.Usingthis method of CRO powder-injection content and recovery rate were determined, theaverage recovery rate could be over99%. The relationship between the concentration ofCRO and fluorescence quenching intensity of Ce3+shows that the quenching type belongsto static quenching.In this paper, using the complexes of rare earth ions with antibiotics or the quenchingeffect between them, thus three rare earth-durg fluorescence system were stablished.Thesemethods achieve the goal of the indirect determination of antibiotics，which have manyadvantages of high sensitivity, low detection limit, simple operation, low sample dosage.