title: [Study on the interaction between alginic sodium diester and azur A and the application].
abstract: The interaction of alginic sodium diester (ASD) and azur A (AA) was studied by absorption spectra. The influence of pH and the molar ratio of AA/ASD on the spectra was investigated. The maximum binding number (N = 168) and the binding equilibrium constant (K = 3.25 x 10(6)) of the alginic sodium diester and azur A were obtained by the theoretical model. The new method for the determination of ASD was developed by the formation of ASD-AA ion-association complex that caused the fading of the AA. The detection limit is 0.009 microg x mL(-1). The method has the advantages of simplicity, stable system, good accuracy and selectivity, and was applied to the determination of alginic sodium diester in tablets with satisfactory results.
authors.affiliation: Chemical College of Yantai University, Yantai 264005, China. yongming_liu@163.com
authors.forename: Yong-ming
authors.initials: YM
authors.lastname: Liu
authors.forename: Gui-zhi
authors.initials: GZ
authors.lastname: Li
authors.forename: Fei
authors.initials: F
authors.lastname: Pan
mesh_terms: D000464:Alginates / Q000032:analysis* / Q000737:chemistry; D001399:Azure Stains / Q000032:analysis* / Q000737:chemistry; D004952:Esters; D006863:Hydrogen-Ion Concentration; D012964:Sodium / Q000032:analysis* / Q000737:chemistry; D013053:Spectrophotometry / Q000379:methods*
chemical_list: D000464:Alginates; D001399:Azure Stains; D004952:Esters; D012964:Sodium; C025818:Azure A