title: Adsorption characteristics of amino acids on to calcium oxalate.
abstract: Adsorption of amino acids on to calcium oxalate found in urinary calculus has been studied and the adsorption characteristics were analyzed. Pseudo-first-order, pseudo-second-order and intraparticle diffusion models were used to fit the kinetics data. The pseudo-second-order model best described the dynamic behavior of the adsorption process. The uptake of glutamic acid and aspartic acid were found to decrease as solution pH increasing from 4 to 8. The experimental data obtained at different pH conditions were analyzed and fitted by Langmuir, Freundlich, Redlich-Peterson, Temkin and Sips isotherm models using linear and nonlinear regression analysis. Error analysis (correlation coefficient, residual root mean square error and chi-square test) showed that the Langmuir I isotherm model and the non-linear form of Sips isotherm model should be primarily adopted for fitting the equilibrium data. The maximum adsorption capacity of glutamic acid and aspartic acid onto calcium oxalate monohydrate crystals are 0.059 and 0.066μmol/g at pH 4, respectively. These studies have the vital significance for research aimed at exploring the role of urinary amino acids effect the formation process of calcium oxalate crystals found in urinary calculus and for potential application in the design of synthetic peptides used for urinary calculi therapy.
authors.affiliation: Guangxi Colleges and Universities Key Laboratory of Utilization of Microbial and Botanical Resources, College of Marine Sciences and Biotechnology, Guangxi University for Nationalities, Nanning 530006, Guangxi, PR China.
authors.forename: Junbin
authors.initials: J
authors.lastname: He
authors.affiliation: Key Laboratory of New Techniques for Chemical and Biological Conversion Process, School of Chemistry and Chemical Engineering, Guangxi University for Nationalities, Nanning 530006, Guangxi, PR China. Electronic address: rihuilin@aliyun.com.
authors.forename: Rihui
authors.initials: R
authors.lastname: Lin
authors.affiliation: Guangxi Colleges and Universities Key Laboratory of Utilization of Microbial and Botanical Resources, College of Marine Sciences and Biotechnology, Guangxi University for Nationalities, Nanning 530006, Guangxi, PR China.
authors.forename: Han
authors.initials: H
authors.lastname: Long
authors.affiliation: Guangxi Colleges and Universities Key Laboratory of Utilization of Microbial and Botanical Resources, College of Marine Sciences and Biotechnology, Guangxi University for Nationalities, Nanning 530006, Guangxi, PR China.
authors.forename: Yuwei
authors.initials: Y
authors.lastname: Liang
authors.affiliation: Guangxi Colleges and Universities Key Laboratory of Utilization of Microbial and Botanical Resources, College of Marine Sciences and Biotechnology, Guangxi University for Nationalities, Nanning 530006, Guangxi, PR China.
authors.forename: Yangyang
authors.initials: Y
authors.lastname: Chen
mesh_terms: D000327:Adsorption; D001224:Aspartic Acid / Q000737:chemistry*; D002129:Calcium Oxalate / Q000737:chemistry*; D018698:Glutamic Acid / Q000737:chemistry*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008956:Models, Chemical; D012044:Regression Analysis; D012996:Solutions; D014545:Urinary Calculi / Q000737:chemistry*
chemical_list: D012996:Solutions; D002129:Calcium Oxalate; D001224:Aspartic Acid; D018698:Glutamic Acid
keywords: Adsorption; Adsorption isotherms; Aspartic acid; Calcium oxalate monohydrate; Glutamic acid; Urinary calculus