Thermodynamic analysis of polyphenols retention in polymer resin chromatography by van’t Hoff plot and isothermal titration calorimetry

•Adsorption enthalpy values of polyphenols in polymer chromatography were obtained.•Isothermal titration calorimetry (ITC) and van’t Hoff (VH) plots were used.•Linear gradient elution (LGE) and isocratic elution (IE) were used for VH plots.•Enthalpy values obtained by VH plots using LGE and IE and b...

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Bibliographic Details
Published inJournal of Chromatography A Vol. 1608; p. 460405
Main Authors Simoes-Cardoso, Joao C., Yoshimoto, Noriko, Yamamoto, Shuichi
Format Journal Article
LanguageEnglish
Published Netherlands Elsevier B.V 20.12.2019
Subjects
Adsorption
Adsorption enthalpy
Calorimetry
Chromatography
Gradient elution
Isocratic elution
Isothermal titration calorimetry
Polymers - chemistry
Polyphenol
Polyphenols - analysis
Polyphenols - metabolism
Polystyrene resin
Polystyrenes - chemistry
Thermodynamics
Vinyl Compounds - chemistry
Water - chemistry
Adsorption enthalpy
Polystyrene resin
Polyphenol
Isothermal titration calorimetry
Gradient elution
Isocratic elution
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Summary:•Adsorption enthalpy values of polyphenols in polymer chromatography were obtained.•Isothermal titration calorimetry (ITC) and van’t Hoff (VH) plots were used.•Linear gradient elution (LGE) and isocratic elution (IE) were used for VH plots.•Enthalpy values obtained by VH plots using LGE and IE and by ITC were similar.•Adsorption enthalpy values obtained with ITC and VH plots were exothermic. Temperature effect on the adsorption enthalpy of polyphenols was analyzed with van’t Hoff plots using the distribution coefficient, K, determined with isocratic and gradient elution chromatography. Catechin and epigallocatechin gallate (EGCG) were used as model polyphenols. The stationary phase was polystyrene-divinylbenzene (PS-DVB) resin particles and the mobile phase was an ethanol-water mixture. The values of adsorption enthalpy determined by chromatography and isothermal titration calorimetry were obtained in the temperature range of 283 and 318 K. The results obtained by van’t Hoff plots were consistent with the ones obtained with the isothermal titration calorimetry (ITC). The interaction between PS-DVB particles and the polyphenols was found to be exothermic with negative values of enthalpy, –30.1 and –37.7 kJ/mol for catechin and EGCG, respectively.
ISSN:0021-9673
1873-3778
DOI:10.1016/j.chroma.2019.460405