New Statistical Approach to a Gas Chromatography Retention Model:  Application to Dichlorophenol Isomers

and, Yves Claude Guillaume; Guinchard, C.

doi:10.1021/jp971037h

Cited by 23 publications

(11 citation statements)

References 33 publications

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“…Therefore, the retention mechanism can be thought to be independent of the solute molecular structure. For a set of compounds where there is enthalpy−entropy compensation, the slope of ln k ‘ versus −Δ H ° will be the same for the same type of reaction. − …”

Section: Resultsmentioning

confidence: 99%

Symmetry Breaking during the Formation of β-Cyclodextrin−Imidazole Inclusion Compounds: Capillary Electrophoresis Study

Guillaume

Peyrin

1999

Anal. Chem.

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A mathematical model was developed for the estimation of binding constants by capillary electrophoresis. The effective electrophoretic mobility in a solute mixture is dependent on the cyclodextrin concentration in the background electrolyte (BGE) as well as the stoichiometry and the binding constant of the guest-cyclodextrin complex. As well, a determination of the degree of complexation, nc (the percent of complexed guest) could be carried out. The model was applied to a series of imidazole derivatives. Thermodynamic data for the solute complexation mechanism were calculated. Different van't Hoff plot shapes of the degree of complexation were observed with different BGE pH values, indicating a change in the solute complexation mechanism. Enthalpy-entropy compensation revealed that the solute complexation mechanism was independent of the imidazole derivative molecular structure, the same at pH = 4.5, 5.0, 5.5, 6.0, and 6.5 but changed at pH = 7.0 and 7.5. Topological defects formed during a symmetry-breaking transition could be responsible for the modification of the structure of the cyclodextrin cavity and explained the nc variations in relation to pH and temperature.

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Section: Resultsmentioning

confidence: 99%

Symmetry Breaking during the Formation of β-Cyclodextrin−Imidazole Inclusion Compounds: Capillary Electrophoresis Study

Guillaume

Peyrin

1999

Anal. Chem.

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“…It is known that the retention factor at temperature T, for the enantiomer X denoted kЈ X,T , is related to the change in free energy (⌬G°I ,II,X ) T incurred during the transfer between the mobile and stationary phases. This relationship is expressed by (Guillaume and Guinchard, 1997):…”

Section: Intracavitary Gibbs Free Energy Changes Between Solute and Hsamentioning

confidence: 99%

Characterization of Solute Binding at Human Serum Albumin Site II and its Geometry Using a Biochromatographic Approach

Peyrin

Guillaume

Guinchard

1999

Biophysical Journal

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Chiral recognition mechanism relationships for binding at site II on human serum albumin (HSA) were investigated using D, L dansyl amino acids. Sodium phosphate salt was used as a solute-HSA interaction modifier. A new model was developed using a biochromatographic approach to describe the variation in the transfer equilibrium constant with the salt concentration, i.e., the nature of the interactions. The solute binding was divided into two salt concentration ranges c. For the low c values, below 0.03 M, the nonstereoselective interactions constituted the preponderant contribution to the variation in the solute binding with the salt concentration. For the high c values, above 0.03 M, the solute binding was governed by the hydrophobic effect and the stereoselective interactions. The different contributions implied in the binding process provided an estimation of both the surface charge density (sigma/F) and the surface area of the site II binding cavity accessible to solvent, which were found to be equal to around 10.10(-7) mol/m(2) and 2 nm(2). As well, the excess of sodium ions excluded by the solute transfer from the surface area of the pocket were about(-0.7) for dansyl norvaline and (-0.8) for dansyl tryptophan.

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“…(3), when enthalpy-entropy compensation is observed for phenol derivatives, all of them have the same free energy AGe ~ at compensation temperature r162 [41] and thus will have the same net retention at the compensation temperature /~ [37,[41][42][43][44]. According to Eq.…”

Section: Theorymentioning

confidence: 99%

Chromatographic framework for analysing lithium perchlorate salt dependence on solute binding mechanisms to porous graphitic carbon surfaces

et al. 2003

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KeyWordsColumn liquid chromatography Porous graphitic carbon Salute bTndTng mechanism LithTum perchlorate Summary A general model to describe the lithium perchlorate salt effect on both phenol derTvatTve-porous graphitic carbon (PGC) association and the selectivity process is presented. Thermody namic functions of solute transfer from mobile phase to PGC surface were determined. Varia tion plots of solute transfer data versus lithium perchlorate concentration (x) in the bulk solvent indicated a change in both the solute PGC assodation and selectivity mechanisms. Enthalpy entropy compensation reveals that this assodation process is independent of the molecular structure of phenol. This study shows the Tmportance of taking into account, (a) salvation by lithium perchlorate in the bulksolvent and (b) possible perchlorate-anTon adsorption on porous graphTtic carbon Tn order to determine optTmum conditTons forseparation of phenol deriva-tTves Tn this system.

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New Statistical Approach to a Gas Chromatography Retention Model: Application to Dichlorophenol Isomers

Cited by 23 publications

References 33 publications

Symmetry Breaking during the Formation of β-Cyclodextrin−Imidazole Inclusion Compounds: Capillary Electrophoresis Study

Symmetry Breaking during the Formation of β-Cyclodextrin−Imidazole Inclusion Compounds: Capillary Electrophoresis Study

Characterization of Solute Binding at Human Serum Albumin Site II and its Geometry Using a Biochromatographic Approach

Chromatographic framework for analysing lithium perchlorate salt dependence on solute binding mechanisms to porous graphitic carbon surfaces

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