Study On The New Method For The Determination Of Daunorubicin, Meloxicam And Cadmium By Fluorescence Spectroscopy And Resonance Rayleigh Scattering

This paper mainly studies interaction of daunorubicin, meloxicam and cadmium with meso-tetrakis (4-sulfonatophenyl) porphyrin, uranyl acetate,1,10-phenanthorline and erythrosine, and set up fluorescence spectroscopy and resonance Rayleigh scattering for the determination of them. The mechanism of interactions was investigated by absorption spectroscopy and computational approach of quantum chemistry. The new methods for determination of daunorubicin, meloxicam and cadmium were established, they also have been successfully applied to the quick determination in practical samples. The main work of this thesis is as follows:1. Fluorescence Quenching and Spectrophotometric Methods for the Determination of Daunorubicin with meso-tera (4-sulphophenyl) porphyrin as ProbeIn this work, a synthetic meso-tera (4-sulfophenyl) porphyrin (TPPS4) was used as a probe to determine daunorubicin (DNR) by fluorescence quenching and spectrophotometric methods. At pH4.6potassium acid phthalate-NaOH buffer solution, a1:1complex of DNR interacted with TPPS4formed via the electrostatic attractions and hydrophobic interactions, thus resulted in TPPS4fluorescence quenching and absorption spectra change. The maximum excitation wavelength (λex) and the maximum emission wavelength (λem) are435nm and672nm, respectively. The fluorescence quenching values (ΔF) are the good linear relationship to the concentration of DNR in the range of0.8-6.0mg·L-1. The method exhibits high sensitivity with the detection limit (3σ) being27.0ng·mL-1. Meanwhile, the absorbance decreased at433nm and a new absorption peak appeared at420nm. The absorbance value (ΔA) and the concentration of DNR were accorded with Lambert-Beer law in a certain range. The molar absorptivity was7.75x104L-mol-1·cm-1for fading spectrophotometry and5.19x104L-mol-1·cm-1for enhanced spectrophotometry. The molar absorptivity could achieve1.29x105L-mol-1·cm-1for dual-wavelength overlapping spectrophotometry. The optimum reaction conditions, influencing factors and the effect of coexisting substances have been investigated in our experiment. The results showed that the method had a good selectivity and could be applied to determine DNR in serum and urine samples. In addition, the combine ratio between DNR and TPPS4was measured and the charge distribution before and after reaction was calculated by quantum chemistry calculation AM1method. The type of fluorescence quenching was discussed by the absorption spectra change,Stern-Volmer plots and fluorescence lifetime determination.2. A Rapid and Highly Sensitive Fluorimetric Method for the Determination of Meloxicam Using Uranyl AcetateIn this work, the fluorescence of a metal ion (UO22+) was exploited for the determination of meloxicam. The fluorescence quenching values of Uranyl Acetate (UA) showed an excellent linear relationship to the concentration of meloxicam (MLX) over the range of0.02-7.5μg·mL-1. The detection limit (3a) was4.49ng·mL-1, which was lower than or comparable to most of the previously reported methods. The proposed method was applied satisfactorily to the assay of MLX in tablet and capsule samples. The optimum reaction conditions, influencing factors and effects of coexisting substances have been investigated. And the absorption spectrum, quenching constants (Kq) and Stern-Volmer plots confirmed that this was a dynamic quenching process.3. Determination of Cadmium by Fluorescence Enhancement Method with1,10-phenanthroline as ProbeIn pH5.5Britton-Robinson (BR) buffer solution, Cd (II) reacted with phen and resulted in the fluorescence enhancement of the reaction system, the maximum excitation and emission wavelength being328and368nm, respectively. The fluorescence enhancement values (ΔF) of phen showed good linear relationship to the concentration of Cd (II) in the range of0.4-21.0μg·mL-1. The method exhibited a high sensitivity with a detection limit (3σ/K) of138.9ng·mL-1. The optimum reaction conditions, influencing factors and the effect of coexisting substances were investigated in the experiment. The results showed that this method had a good selectivity and could be applied to determine Cd (II) in environmental water samples. 4. Study on Erythrosine-Phen-Cd (Ⅱ) Systems by Absorption Spectra, Resonance Rayleigh Scattering and Their Analytical ApplicationsThis process could make system absorption spectra change and produce obvious fading reaction at528nm. ΔA of system was directly proportional to the concentration of Cd (II). Hereby, a high sensitive spectrophotometry which determine Cd (Ⅱ) was established. The molar absorption coefficient was2.29x105L-mol-1·cm-1, the detection limit of Cd (Ⅱ) was26.5ng·mL-1. Furthermore, this process also caused change of scatter spectra. The resonance Rayleigh scattering (RRS) of this system was obviously changed at371and590nm, and second-order scattering (SOS) and frequence doubling scattering (FDS) of this system were obviously changed at640and350nm, respectively. Under the optimum conditions, the scattering intensities(ΔIRRS、AIsos and AIFDS) had good linear relationship with the concentration of Cd (Ⅱ) in certain ranges. The methods had high sensitivity and can be used to detect the trace Cd (Ⅱ) in the environment. The detection limit of Cd (Ⅱ) were1.27ng·mL-1,1.39ng·mL-1,4.03ng·mL-1,5.92ng·mL-1and14.7ng·mL-1for dual-wavelength overlapping resonance Rayleigh scattering (DWO-RRS), RRS (371nm), RRS (590nm), SOS and FDS, respectively. The characteristics of RRS、SOS、FDS and absorption spectra of the system, the suitable reaction conditions and effect factors were investigated. Take RRS for example to investigate the method of selectivity. It had been applied to the determination of Cd (Ⅱ) in environmental water samples. The recovery range was between93.0%and103.0%and the relative standard deviation (RSD) was between2.5%and4.3%. The result was satisfactory with atomic absorption spectroscopy as the control experiment.