¦¢-cyclodextrin In Spectral Applied Research

β-cyclodextrin(β-CD) and its various derivatives are well known, which structure is that of a truncated cone with the hydrophilic outer surface and a hydrophobic internal cavity. Because of this peculiar molecular structure,β-CD and its derivatives could include guest molecules to form inclusion complexes. At present, they had been widely used in various fields, such as medicine, chemistry, agriculture, and so on. The major contents of this paper are described as follows:(1) Effect ofβ-cyclodextrin-microemulsion on determination of trace Bi(III) by spectrofluorimetryThe sensitizing effect ofβ-cyclodextrin(β-CD) andβ-CD-CTAB on the determination of Bismuth(III) by spectrofluorimetry was studied. The results showed thatβ-CD had no sensitizing effect on Bi(III)-8-hydroxyquinoline(HQ). Whenβ-CD-CTAB- microemulsion was added, the sensitizing effect on the determination of Bi(III)-HQ was the highest. The proposed method was applied to the determination of Bi(III) in standard sample and real sample with satisfactory results.(2) Study on the inclusion interactions ofβ-cyclodextrin and its derivative with dyes by spectrofluorimetry and its analytical applicationThe inclusion interactions ofβ-cyclodextrin and hydroxypropyl-β-cyclodextrin (HP-β-CD) with dyes were developed by spectrofluorimetry. The main factors (the host molecule, the guest molecule, and the pH) for the inclusion interaction were discussed in detail. At the same time, the inclusion interaction of HP-β-CD and vitamin B6 (VB6) was investigated with the competitive fluorescence inclusion method and the inclusion constant of HP-β-CD and VB6 was obtained by indirect fluorescence technique. On the basis of the linear relationship between the fluorescence intensity and the concentration of VB6, a competitive fluorescence inclusion method for the determination of VB6 was developed. The method has been successfully applied to the determination of VB6 in synthetic samples, tablets and injections with satisfactory results. (3) Hydroxypropyl-β-cyclodextrin enhanced determination for the vitamin B₁₂ by fluorescence quenching methodA novel fluorescence quenching method for the determination of vitamin B₁₂ (VB₁₂ ) had been developed. It was based on that the fluorescence intensity of erythrosine sodium (ES) could be enhanced by Hydroxypropyl-β-cyclodextrin due to the formation of inclusion complex (HP-β-CD-ES), while the fluorescence intensity of HP-β-CD-ES was diminished after adding VB₁₂ into the system, and there was a linear relationship between the fluorescence quenching value of the system and the concentration of VB₁₂. The mechanism of the determination of VB₁₂ was discussed. The results showed that under the optimal conditions, the linear range of calibration curve for the determination of VB₁₂ was 0.0².1×10^-5 mol/L, and the detection limit was 1.8×10^-7 mol/L. It could be satisfactorily applied to the determination of VB₁₂ in injections.(4) Determination of Protein by Hydroxypropyl-β-cyclodextrin Sensitized Fluorescence Quenching method with a fluorescence Probe of erythrosine sodiumThe fluorescence spectral behavior of interaction of erythrosine sodium and bovine serum albumin (BSA) was investigated in Hydroxypropyl-β-cyclodextrin medium at pH 5.8. The excitation and emission wavelengths were 527nm and 549nm, respectively. HP-β-CD could form inclusion complex with ES, thereby increasing the fluorescence intensity of ES and enhancing the sensitivity of the system. After adding BSA, the fluorescence intensity of ES-HP-β-CD was diminished, and there was a linear relationship between the fluorescence quenching value of the system and the concentration of BSA. Based on this, a novel fluorescence quenching method for the determination of protein with erythrosine sodium as a fluorescence probe has been developed. Under the optimal conditions, the linear range of calibration curve for the determination of BSA was 0.0³2.0μg/mL, and the detection limit was 49.2ng/mL. It has been applied to the determination of proteins in human serum samples with satisfactory results.