Effect of eluent composition on thermodynamic properties in high-performance liquid chromatography

Sander, Lane C.; Field, Larry R.

doi:10.1021/ac50063a005

Cited by 88 publications

(35 citation statements)

References 22 publications

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“…more than proportional with p. To check, whether It is probable that, like for many low-molar-mass this effect is real, at first the standard deviation of solutes, sorption will be dominated by partitioning retention time was calculated from 10 determinations [22]. At higher %THF, the structure of the C layer at 108C and 708C respectively for both high-and 18 will be more 'open' and oriented towards the mobile low-molar-mass oligomers, and was found to be phase [29]. This means that penetration of this layer 0.020 min for low-molar-mass oligomers and 0.035 will be easier, thus causing less ordering of solutes min for high-molar-mass oligomers.…”

Section: Hplc Equipment 33 Determination Of Phase Ratio and Ksec Vamentioning

confidence: 99%

“…2). At lower temperatures, the C chains become more 18 rigid which will especially affect the retention behaviour of solutes that (partly) penetrate into the layer, thus giving rise to curved van't Hoff plots. This effect was already reported for other low-molarmass solutes in various reversed-phase systems [40].…”

Section: Hplc Equipment 33 Determination Of Phase Ratio and Ksec Vamentioning

confidence: 99%

“…The compensation temperatures which were deter-3076248C (95% confidence intervals) for oligomers mined from linear regression analysis of the entire 3-15 and 147668C for oligomers [16][17][18][19][20][21][22][23][24][25][26]. The fact curves for both polymers are 175688C for PS and that both values differ significantly, again indicate a 1206128C for PE.…”

Section: Hplc Equipment 33 Determination Of Phase Ratio and Ksec Vamentioning

confidence: 99%

“…r 0 0 d tography (RPLC) is to investigate the temperature dependence of isocratic retention [15][16][17][18][19][20][21][22][23][24][25][26][27]. From the in which K is the chromatographic equilibrium In order to get a better understanding of their DS are the Gibbs free energy, standard enthalpy and retention behaviour, in this study the determination standard entropy of transfer of a solute from the and evaluation of thermodynamic parameters for mobile to the stationary phase.…”

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“…Furthermore, it was shown that these V 5 (%C)(M)(W ) /(100)(12.011)(n )(r) was observed under certain conditions which could (7) be explained from a phase transition of the C 18 column material [20]. This influences the partition If the same physical-chemical process determining process, which has been shown to be the main the energies of the retention process is operative for process determining retention on C derivatized the various situations taken into account in the 18 silica [31]. Partitioning and partial insertion of the compensation plot, then a linear dependence, and alkyl chain was found to be dependent on the carbon therefore only one compensation temperature, will be number of a homologous series, which could be found.…”

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Study on the retention behaviour of low-molar-mass polystyrenes and polyesters in reversed-phase liquid chromatography by evaluation of thermodynamic parameters

Philipsen¹,

Claessens

Lind³

et al. 1997

Journal of Chromatography A

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. (1997). Study on the retention behaviour of low-molar-mass polystyrenes and polyesters in reversed-phase liquid chromatography by evaluation of thermodynamic parameters. Journal of Chromatography, A, 790(1-2), 101-116. DOI: 10.1016/S0021-9673(97)00739-5 General rightsCopyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights.• Users may download and print one copy of any publication from the public portal for the purpose of private study or research.• You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal ? Take down policyIf you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim. AbstractPolymers can be characterized under sorption conditions, to obtain information on molar mass and chemical composition. In order to get a better understanding of their retention behaviour under such conditions, the evaluation of thermodynamic parameters obtained from van't Hoff analyses on low-molar-mass polystyrenes (PS) and polyesters (PE) in various THF-water mixtures on a C column is described in this study. Linear van't Hoff behaviour was observed in almost all 18 cases. Negative values for both DH and DS were found for both PS and PE oligomers, which increase with increasing %THF. For DS this is explained from multi-site attachment effects. For PS, the non-linear relations between DH and DS, and degree of polymerization ( p) could be properly described by the Stockmayer-Fixman equation. Although less clear, similar trends were found for PE. For PS, evidence for penetration effects of oligomer chains into the bonded chains was obtained. Martin plots for both PS and PE were shown to be non-linear in all investigated eluent compositions. The extent of non-linearity is suggested to depend on the conformation of a polymer in solution. No distinct enthalpy-entropycompensation temperature (EECT) independent of p was found for PS, thus confirming the findings of an earlier study in which no exact molar mass independence was found under critical conditions. Further evaluation of EECT for PS oligomers revealed a retention mechanism independent of the binary eluent composition. This indicates that conclusions from this study can also be used for a qualitative understanding of sorption mechanisms in the gradient elution mode. Finally, for PS it was shown that DG equals zero under critical conditions, thus confirming theoretical predictions. © 1997 Elsevier Science B. V.

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Section: Hplc Equipment 33 Determination Of Phase Ratio and Ksec Vamentioning

confidence: 99%

Section: Hplc Equipment 33 Determination Of Phase Ratio and Ksec Vamentioning

confidence: 99%

Section: Hplc Equipment 33 Determination Of Phase Ratio and Ksec Vamentioning

confidence: 99%

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confidence: 99%

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confidence: 99%

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Study on the retention behaviour of low-molar-mass polystyrenes and polyesters in reversed-phase liquid chromatography by evaluation of thermodynamic parameters

Philipsen¹,

Claessens

Lind³

et al. 1997

Journal of Chromatography A

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Thermodynamic behaviour in capillary electrochromatography

Jiskra¹,

Claessens²,

Cramers³

2002

J. Sep. Science

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Investigation of the low temperature effect in micro high performance liquid chromatography‐open tubular microcapillary column

Jinno

Hirata

1981

J. High Resol. Chromatogr.

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The experimental results are represented in Figure 1 ; as in ref.[5], the log k'and Csaxes have opposite directions. Although only few values of solubility are available, the variations of log kvalues and log CS values of 2-hydroxynaphthalenc? are clearly seen to be parallel; some deviations are observed for the less accurately known low K and high Cs values. For 2,3-dihydroxynaphthalene only two Cs values are available in the range of good accuracy, so thatonlyageneral ideacan begainedoftheanalogiesoflog K and log Cs; however, the vertical distance between the plots is clearly much larger than for 2-naphthol. This is in accord with earlier observations [3]. The retention vs. eluent composition relationships are approximately linear, as is frequently observed for liquidlliquid and liquidlsolid systems of this type [7,8].The experimental results confirm the important role of solution effects for nonpolar adsorbents [4,9-141; however, for polar solutes the selectivity (A log K) is apparently attributable not only to differences of solubility (A log CS) but also to other factors.

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Effect of eluent composition on thermodynamic properties in high-performance liquid chromatography

Cited by 88 publications

References 22 publications

Study on the retention behaviour of low-molar-mass polystyrenes and polyesters in reversed-phase liquid chromatography by evaluation of thermodynamic parameters

Study on the retention behaviour of low-molar-mass polystyrenes and polyesters in reversed-phase liquid chromatography by evaluation of thermodynamic parameters

Thermodynamic behaviour in capillary electrochromatography

Investigation of the low temperature effect in micro high performance liquid chromatography‐open tubular microcapillary column

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