Study On The New Methods For Ceric Ammonium Nitrate,riboflavin And Gatifloxacin By Fluorescence Spectrophotometry

In recent years,synthesis of carbon dots and its application have attracted more and more attention.Carbon dots have been applied in fields of environmental monitoring,biological imaging,biological molecular detection analysis and drug delivery based on the advantages of small size,low toxicity,light stability,long fluorescent life time and good solubility in water,.Fluorescence spectrometry is more and more widely applied in environment,medicine,biology,medicine,food and other fields with advantages of simple operation,less reagent dosage,good selectivity,high sensitivity,etc.This paper mainly studied the synthesis of carbon dots and its application in water pollutants ammonium cerium nitrate and drug fluorescence spectrum detection application of riboflavin,additionally,another new fluorescence spectrometry method is established for determination of gatifloxacin.1.The hydrothermal synthesis of fluorescent carbon dots,characterization and fluorescence properties studyThe carbon dots was systhesised with maleic acid and ethylene diamine as precursor by one step hydrothermal method.Then carbon dots solution was placed in a centrifuge for 10 min at a speed of 8000 r/min to remove large particles of solid impurities,the filtrate with 0.22 mM water-based microporous filter membrane,and dialysis after 12 h.Dialysate was vacuum dried for solid flake carbon dots.We studied the fluorescence properties and the effects of p H on carbon dots and through ultraviolet absorption,infrared spectrum,transmission electron microscopy?TEM?for characterization.2.Research on fluorescence spectrometry CDs-CAN system and its analytical applicationA simple,high efficiency,good selective fluorescence spectrometry method for determination of CAN was established with CDs as fluorescence probe and ceric ammonium nitrate?CAN?as the fluorescence quenching agent.CAN effectively quenched fluorescence of carbon dots at p H 3.0 buffer solution with an excitation peak of 445 nm and an emission peak of 490 nm.Under optimized conditions,fluorescence quenching value of carbon dots had good linear relationship to concentration of CAN in the range of 4.0-140 mg m L^-1.The detection limit was 1.4 mg m L^-1.Common interferents were examined,the results showed that the method has good selectivity and the test results are satisfactory when the method was used for the determination of CAN in water samples.The recovery rate was 96.2%-101.4% showed that the method has high accuracy.Discussed the quenching mechanism of CDs-CAN system based on the temperature curve and the UV absorption spectra.3.Research on fluorescence spectrometry CDs-VB₂ system and its analytical applicationWith CDs as the energy donor and riboflavin as the energy acceptor,at p H 7.0 buffer solution,fluorescence intensity of the CDs-VB₂ system was enhanced as riboflavin was added with an excitation peak of 445 nm,while the maximum emission wavelength was redshift at about 520 nm.Under optimized conditions,the linear concentration of riboflavin was 3.0-37.5×10-6 mol L^-1.The detection limit was 0.52 mM.common coexist substance and tablet accessories were Investigated for the effect on the method,and the results showed that the method has good selectivity.Method is successfully applied to the determination of riboflavin in tablets.In addition,the mechanism of reaction system should belong to the fluorescence resonance energy transfer according to the ultraviolet absorption and fluorescence spectrum.4.The charge transfer fluorescence spectrometry method for determination of gatifloxacinIn the charge-transfer reaction between chloranilic acid and gatifloxacin?GFLX?,where chloranilic acid acts as a p-electron acceptor and GFLX acts as an electron donor,the fluorescence intensity of the charge-transfer complex is ten times higher than that of GFLX itself.The complex shows a stable light purple color in methanol.Spectrofluorimetric determination of GFLX is simple,accurate,and rapid with good selectivity and high sensitivity.The method shows a good linear relationship with the concentration of GFLX in the range of 0.12-10.00 mg m L^-1 with a high correlation coefficient of 0.9991.Determination of GFLX in tablets with recovery of?100.46±2.04?% obtained a satisfactory result.