Study And Applicion On Molecular Emission Spectra In Rare-earth Analysis Of Environmental Samples

Rare-earth elements widely researched in the field of environmental science.At present, in the environmental analysis pay more attention to the rare-earth analysis. In this article,Lanthanum,Europium,Cerium(Ⅲ),Cerium(Ⅳ) four kinds of rare-earth elements had been established new molecular fluorescence system,with Fluorescence quenching spectroscopy;Sensitized fluorescence spectroscopy; Synchronous fluorescen spectrometry;Three-Dimensional fluorescence spectrometry;Resonance light scattering spectroscopy, in order to quantitative Applications Analysis and Discuss the qualitative theory. The basic experimental theory to solve the practical problems of environmental analysis and monitoring of trace rare earth and its stored in the body of life,the transmission mechanism and pathology basic experimental theory.There are seven chapters in a dilThis part discusses the fluorescence quenching spectraand the resonance light scattering properties of Ce(Ⅳ)-I3--MG,based on the reaction between bromate ion peroxide and execss KI to I3-reacted with malachite green to form association particles,The resonance light scattering(RLS) intensity of sulfanilic acid was Sensitized by Ce(Ⅳ),the magnitude of decrease RLS intensity (IRLS) with directly proportional to the concent ration of Ce(Ⅳ). The linear calibration range for nitrite was0.02-0.85μg/mL and The linear equation was IRLS=36.91C(μg/mL)+1.19,and the relative coefficient was0.9984,with a detection limit of7.8ng/mL(3s).The proposed method was used in the determination of Ce(Ⅳ) in in the rare earth sample,giving recovery range of96.20%～104.00%.Under the imitated physiological condition of animal body,The binding reaction of BSA with La(Ⅲ) was studied by fluorescence spectroscopy.The quenching mechanism of intrinsic fluorescence of BSA with La(Ⅲ) was studied by Stern-volmer curve,Lineweaver-Burk curve and double reciprocal curve.The experimental results showed that static quenching were the main factors of the quenching mechanism of intrinsic fluorescence. The quenching constants and diffusion constants between BSA and La(Ⅲ)were measured,and all of the numbers of binding sites are2.673. The thermodynamic parameter of binding reaction was determined by the binding, it’s showed La(Ⅲ) into the cavity formed in the sub-structure of BSA mainly by Hydrogen bonding、Vander force Walls.Synchronou-s spectroscopy was used to investigate the conformational changes of BSA.The spectral properties of Europium (Eu(Ⅲ)) were studied.Based on the intense luminescence of Eu(Ⅲ)-Quercetin-Hexadecy trimethy ammonium Bromide(CTAB) complex in HAc-NaAc medium produce significant fluorescence peak, and gradually increased with the increase in fluorescence intensity of Eu(Ⅲ) ion concentration, a simple sensitive fluorimetry for determination of Eu(Ⅲ) was developed. The intra molecular energy transfer models had been set up.Under the optimum experimental conditions,The linear calibration range for nitrite was0.01-0.80μg/mL and The curve regression equation of IF=25.56C(μg/mL)+1.32with correlation coefficient of0.9972and a detection limit of6.3ng/mL(3s).The proposed method was used in the determination of europium in the rare earth sample,giving recovery range of95.83%～106.89%with satisfactory results.The interaction of Trypsine with rare-earth Ce (Ⅲ) was studied by fluorescence spectrome try.The quenching mechanism of intrinsic fluorescence of Trypsine with Ce (Ⅲ) were studied by Stern-volmer curve,Lineweaver-Burk curve and double reciprocal curve.The experimental results showed that static quenching was the main factors of the quenching mechanism of intrinsic fluorescence.The quenching constants and diffusion constants between Trypsine and Ce (Ⅲ) was measured, and the numbers of binding site is2.173.The thermodynamic parameters of binding reactions were determined by the binding constants in285K and295K.According to these,the interaction between Trypsine and Ce(Ⅲ) was driven mainly by Hydrophobic interaction.The results of synchronous flurescence spectroscopy indicate that Ce (Ⅲ) had little effect of Tyrosine residues,Tryptophan residues,resulti-ng not in the change of the Hydrophobic environment and Polarity of the environment.The proposed methods were rapid, easy sample handling, selectivity and high sensitivity which had practical value. While, the basis theory we measured can provide a reference for the further research.