title: A novel method for the determination of the degree of deacetylation of chitosan by coulometric titration.
abstract: A novel method to determine the degree of deacetylation of chitosan is described. In this method, the coulometric titrant OH- is generated by the electrolysis of water. The OH- reacted with the residual hydrochloric acid in chitosan solution and the degree of deacetylation was obtained by Faraday's law. The optimized experimental parameters in this study were 1.0 mol/L KCl as supporting electrolyte, 15.00 mA as the intensity of constant current, composite glass electrode as indicating electrode couples, double platinum generated electrode-platinum wire auxiliary electrode as working electrode pairs, pH 3.80 as the titration end-point. The degree of deacetylation in the four samples, which varied from 70 to 95% were measured. The results were similar to those from 1H NMR and the standard deviations were lower than 0.5%. With merit of simplicity, convenience, quickness, high accuracy and precision, automatic detection of titration end-point and low-cost, the proposed method will be very useful in the industrial production.
authors.affiliation: Department of Chemistry, Wuhan University of Technology, Wuhan 430070, PR China.
authors.forename: Chao
authors.initials: C
authors.lastname: Wang
authors.affiliation: School of Information Engineering, Chang Jiang Engineering Vocational College, Wuhan 430070, PR China.
authors.forename: Fang
authors.initials: F
authors.lastname: Yuan
authors.affiliation: Department of Chemistry, Wuhan University of Technology, Wuhan 430070, PR China.
authors.forename: Jiabao
authors.initials: J
authors.lastname: Pan
authors.affiliation: Department of Chemistry, Wuhan University of Technology, Wuhan 430070, PR China.
authors.forename: Shining
authors.initials: S
authors.lastname: Jiao
authors.affiliation: Department of Chemistry, Wuhan University of Technology, Wuhan 430070, PR China.
authors.forename: Ling
authors.initials: L
authors.lastname: Jin
authors.affiliation: Department of Chemistry, Wuhan University of Technology, Wuhan 430070, PR China. Electronic address: caihongwei@whut.edu.cn.
authors.forename: Hongwei
authors.initials: H
authors.lastname: Cai
mesh_terms: D000107:Acetylation; D048271:Chitosan / Q000737:chemistry*; D004572:Electrolysis; D004573:Electrolytes / Q000737:chemistry
chemical_list: D004573:Electrolytes; D048271:Chitosan
keywords: Chitosan; Coulometric titration.; Degree of deacetylation