| Molecular spectroscopy is a method that used to measure intensity and wavelength in the absorption,reflectionor scattered radiation which is generated in the quantization energy level transition of internal material when molecular interact with the electromagnetic radiation. It is the important experimental method of indentifing and determining molecular structure, including ultraviolet-visible spectrum, the near-infrared spectrum and infrared spectrum, resonance Rayleigh scattering, Raman spectroscopic analysis, molecular fluorescence and the phosphorescence and so on. Their characteristics are highly sensitive, simple and rapid. They are the important analytical tools of the material elements of qualitative, quantitative and structural analysis, among ultraviolet-visible spectrum, resonance Rayleigh scattering, molecular fluorescence obtained high sensitivity, simplicity, rapid and good selectivity and so on.Especially, RRS has attracted more and more attention due to its high simplicity and sensitivity. Taking the fluoroquinolone antibiotics as examples, we have studied and developed the new methods for the determination by the molecular spectroscopy. In the thesis, we mainly investigated the interaction between fluoroquinolone antibiotics and dyes, metal ions by the molecular spectroscopy. Besides, the spectral characteristics, the influencing factors and the optimum conditions were studied. The reaction mechanism was discussed too. The main investigated systems are summarized as follows:1,The Absorption Spectra and Resonance Rayleigh Scattering Spectra of Erythrosine and Fluoroquinolone Antibiotics System and theirs Analytical ApplicatioUnder the optimum acidity,erythrosine(Ery) could react with Moxifloxacin(MXFX) and Gatifloxacin(GTF) of fluoroquinolone antibiotics (FLQs) to form 1:1 ion-association complexes, The system reactions resulted in the great enhancement of resonance Rayleigh scattering (RRS) and new RRS spectra appear. Their reaction products of the two drugs had similar spectral characteristics, the maximum RRS wavelengths were situated at 568 nm, of antibiotics drugs, the linear range of two drugs were 0.02～2.7μg/mL(MXFX) and 0.06～10.2μg/mL(GTF) espectively. So a new method for determination of the drugs could be developed and succeed to applied to determine content of the MXFX in Capsule and human urine sample. The reaction mechanism and the reasons for RRS enhancement of the system were investigated in the paper. At the same time the system resulted in the changes of the absorption spectra and have obvious fading effect, the maximum fading wavelengths were situated at 520nm.and Molar absorption coefficients are 5.7×104L·mol-1·cm-1(MXFX) and 5.9×104 L-mol-1·cm-1(GTF)espectively. So the methods could be applied yet to determine the FLQs drugs for fading spectrometry. And at 342 nm and 378 nm had two small scattering peak. At 342 nm the intensities of RRS are proportional to the concentration.2,Study on Resonance Rayleigh Scattering spectra of Phosphowolframic Acid and Fluoroquinolone Antibiotics System and theirs Analytical ApplicationIn a acid medium, phosphowolframic acid (Pwa) could react with Moxifloxacin(MXFX) and Gatifloxacin(GTF)fluoroquinolone antibiotics (FLQs) to form 1:1 ion-association complexes respectively.The system reactions resulted in the great enhancement of resonance Rayleigh scattering (RRS) and new RRS spectra appear. Their reaction products of the two drugs had similar spectral characteristics, the maximum RRS wavelengths were situated at 320 nm. And the intensities of RRS are proportional to the concentration of antibiotics, the linearity range of two fluoroquinolone antibiotics are 0.025～6.0μg/mL(MXFX)and 0.023～9.0μg/mL(GTF) espectively. So a new method for determination of the drugs could be developed and succeed to applied to determine content of the FLQs in Capsule and human urine sample. The reaction mechanism and the reasons for RRS enhancement of the system were investigated in the paper.3,The Absorption Spectra and Resonance Rayleigh Scattering Spectra of Cu(Ⅱ)-fluoroquinolone chelates with Tetrachlorotetraiodo-fluoresceindisodium salt System and theirs Analytical Application In pH 4.2-4.8 Britton-Robinson (B-R) buffer solution, Moxifloxacin(MXFX) and Gatifloxacin (GTF) of fluoroquinolone antibiotics (FLQs) could react with Cu (II) to form chelate cations, which further bind with tetrachlorotetraiodo-fluoresceindisodium salt (Tf) to form FLQs:Cu(II):Tf for 1:1:1 ion association complexes. The system reactions resulted in the great enhancement of resonance Rayleigh scattering (RRS) and new RRS spectra appear. The reaction systems of the two drugs had similar spectral characteristics, the maximum RRS wavelengths were situated at 373 nm, and at 590 nm had one small scattering peak. At 373 nm the intensities of RRS are proportional to the concentration of antibiotics drugs, the linear range of two drugs were 0.031-7.8 mg/L(MXFX) and 0.029-9.0 mg/L (GTF) espectively. So a new method for determination of the drugs could be developed and succeed to applied to determine content of the FLQs in Capsule and human urine sample. The reaction mechanism and the reasons for RRS enhancement of the system were investigated in the paper.4,Simultaneous Dermination of MXFX and GTF by Ultraviolet Spectrophotometry-two lines with one pointIn pH 3.8-5.2 B-R buffer medium, Eosin Y could react with Moxifloxacin(MXFX) and Gatifloxacin(GTF) to form ion-association complexes respectively.The system reactions resulted in the great enhancement of absorption intensities and the great absorbance wavelengtha in 294 nm. And the absorption intensities(△A) are enhanced with the increase of medication concentration in certain ranges. After GTF and MXFX were mixed at a ratio of 1:3, a series of the different concentrations of the mixture drugs reacted with Eosin Y. The absorption intensities(△A) were also directly proportional to the total concentrations of GTF and MXFX at 294 nm. The results showed that the absorption intensities of GTF and MXFX have the additivity. Moreover, the calibration curve for the mixture system was constructed, and the total concentration of GTF and MXFX in mixed samples was obtained.The detection limits and linear ranges of two drugs are 15.1 ng/mL and 0.4-25.2μg/mL for MXFX,22.6 ng/mL and 0.5-27.6μg/mL for GTF with satisfactory results.
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