disulfide-linked

An improved synthesis of disulfides linked @b-cyclodextrin dimer and its analytical application for dequalinium chloride determination by spectrofluorimetry [An article from: Analytica Chimica Acta]
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This digital document is a journal article from Analytica Chimica Acta, published by Elsevier in . The article is delivered in HTML format and is available in your Amazon.com Media Library immediately after purchase. You can view it with any web browser.

Description:
An improved synthesis of @b-cyclodextrin (@b-CD) dimer, containing two @b-CD moieties that are linked through their sides by disulfides was presented. The dimer was characterized by means of IR, ^1H NMR and elemental analysis. The inclusion complexation behavior of @b-cyclodextrin dimer with dequalinium chloride (DQC) was studied in an aqueous NH"4Ac-HAc buffer solution of pH 4.00 at room temperature by spectrofluorimetry. The apparent association constant of the complex was 1.67x10^4lmol^-^1, which showed higher affinity than native @b-CD (K"s=4.99x10^2lmol^-^1). Based on the significant enhancement of fluorescence intensity of DQC, a spectrofluorimetric method with high sensitivity and selectivity was developed for the determination of DQC in bulk aqueous solution in presence of @b-CD dimer. The linear range was 6.38-1.60x10^3ngml^-^1with the detection limit 1.9ngml^-^1. There was no interference from the excipients normally used in tablets and serum constituents. The proposed method was successfully applied to the determination of DQC in tablets and serum.