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dc.contributor.authorLi, H.en
dc.contributor.authorPatrickios, Costas S.en
dc.creatorLi, H.en
dc.creatorPatrickios, Costas S.en
dc.date.accessioned2019-11-21T06:21:10Z
dc.date.available2019-11-21T06:21:10Z
dc.date.issued2001
dc.identifier.urihttp://gnosis.library.ucy.ac.cy/handle/7/55788
dc.description.abstractA homologous series of four oligomers of acetic acid (namely acetic acid, succinic acid, tricarballylic acid, and tetracarboxylic acid) is characterized using isocratic and linear salt gradient anion-exchange chromatography. The double logarithmic plot of the isocratic retention factors versus the salt concentration gives straight lines for all samples. These straight lines (with the exception of the line for the strongly retained succinate peak) have a common intersection point - something which is proved to be a direct consequence of the stoichiometric mass-action ion-exchange model. The characteristic charge and the equilibrium ion-exchange constant (and the corresponding Gibbs free energy of ion exchange, or ΔGexchange) are determined from the isocratic experiments. The characteristic charge agrees satisfactorily with the number of carboxylic acid groups in the samples, and the ΔGexchange value decreases linearly with the characteristic charge. Succinic acid always gives two chromatographic peaks despite the proven chemical purity of the sample. The characteristic charge that is calculated for both of the succinic acid peaks is approximately two. The ΔGexchange value calculated for the weakly retained succinic acid peak falls in the free energy versus characteristic charge straight line defined by the other homologues. The ΔGexchange value of the strongly retained peak is lower than that of the weakly retained peak by 1.85 kJ/mol. The two succinic acid peaks are explained in terms of an equilibrium between two conformers in solution - one binding the solution counterions tightly and the other loosely. An analysis of all samples under a linear salt gradient provides retention times that increase linearly with the number of functional groups. Using an appropriate model (along with the isocratically determined characteristic charge and ion-exchange constant), we predict theoretically the linear gradient retention times, which agree reasonably well with the experimental ones.en
dc.sourceJournal of chromatographic scienceen
dc.source.urihttps://www.scopus.com/inward/record.uri?eid=2-s2.0-0035296589&partnerID=40&md5=a76adcdd860ecc21a9cadd099f5dc992
dc.subjectmodelen
dc.subjectarticleen
dc.subjectpredictionen
dc.subjectunclassified drugen
dc.subjectchemical analysisen
dc.subjectenergyen
dc.subjectstoichiometryen
dc.subjectcalculationen
dc.subjectanion exchange chromatographyen
dc.subjectmassen
dc.subjectsuccinic aciden
dc.subjectacetic aciden
dc.subjectanionen
dc.subjectionen
dc.subjectacetic acid derivativeen
dc.subjectallyl compounden
dc.subjecttetracarboxylic aciden
dc.subjecttricarballylic aciden
dc.titleOligoacetic acid characterization by isocratic and linear salt gradient anion-exchange chromatographyen
dc.typeinfo:eu-repo/semantics/article
dc.description.volume39
dc.description.issue3
dc.description.startingpage87
dc.description.endingpage92
dc.author.faculty002 Σχολή Θετικών και Εφαρμοσμένων Επιστημών / Faculty of Pure and Applied Sciences
dc.author.departmentΤμήμα Χημείας / Department of Chemistry
dc.type.uhtypeArticleen
dc.source.abbreviationJ.Chromatogr.Sci.en
dc.contributor.orcidPatrickios, Costas S. [0000-0001-8855-0370]
dc.gnosis.orcid0000-0001-8855-0370


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