Characterization of reversed-phase columns using the linear free energy relationship

Sándi, Ákos; Nagy, M.H.; Szepesy, L.

doi:10.1016/s0021-9673(00)00733-0

Cited by 66 publications

(22 citation statements)

References 58 publications

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“…Our test uses 65% methanol-35% buffer, the NIST test 80% methanol-20% buffer, and the Tanaka test 80% methanol-20% water. It is known [5] that the absolute value of the hydrophobicity parameter depends on the mobile phase composition. However, the hydrophobicity values of different packings appear to change in a consistent pattern for different reversed-phase packings [5].…”

Section: Hydrophobic Interactionmentioning

confidence: 99%

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Characterization of HPLC packings

Neue¹,

Tran²,

Iraneta³

et al. 2003

J of Separation Science

134

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Several chromatographic test procedures are in use for the characterization of commercially available packings. The results of the test procedure used in our laboratory are updated and further refined. Two well-defined physico-chemical properties of packings can be derived from this test procedure, the hydrophobicity of a packing and the silanophilic activity at pH 7. In addition, our method is unique in its ability to differentiate between classical packings and packings with incorporated polar groups. We can also distinguish CN packings or fluorinated packings. Our database now includes over 100 commercially available packings. The ability of the test to cleanly discriminate between different classes of packings has been strengthened. Limited comparisons with other published tests are now possible as well, and the results of these comparisons are discussed.

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Section: Hydrophobic Interactionmentioning

confidence: 99%

“…It is known [5] that the absolute value of the hydrophobicity parameter depends on the mobile phase composition. However, the hydrophobicity values of different packings appear to change in a consistent pattern for different reversed-phase packings [5]. The other issue is the fact that different probes are used.…”

Section: Hydrophobic Interactionmentioning

confidence: 99%

Characterization of HPLC packings

Neue¹,

Tran²,

Iraneta³

et al. 2003

J of Separation Science

134

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“…In general, the latter interaction forces have more pronounced effect on the stationary phase with shorter hydrocarbon chains (owing to the more easily accessible silica-gel surface there). 41,42 Increasing the vancomycin concentration resulted in increased retention. This trend could be observed more clearly on the C-18 stationary phase at higher chiral-selector concentration.…”

Section: Results and Discussion Enantioselective Separations Of Profementioning

confidence: 99%

Vancomycin as chiral selector for enantioselective separation of selected profen nonsteroidal anti‐inflammatory drugs incapillary liquid chromatography

et al. 2006

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The chiral selector vancomycin was used either as mobile phase additive or bound as a chiral stationary phase (CSP) for the stereoselective separation of seven racemic nonsteroidal anti-inflammatory drugs (NSAIDs), fenoprofen, carprofen, flurbiprofen, indoprofen, flobufen, ketoprofen, and suprofen, by capillary liquid chromatography. The effect of the type of stationary phase, the chiral column Chirobiotic V or the achiral stationary phases Nucleosil 100 C8 HD and Nucleosil 100 C18 HD, and the concentration of vancomycin in the mobile phase on separation of the drug enantiomers were evaluated. All the drugs, except flobufen, were successfully enantioseparated on Nucleosil 100 C8 HD with 4 mM vancomycin present in the mobile phase (composed of methanol and buffer) in the reversed phase mode. On the vancomycin-bonded chiral stationary phase, it was difficult to get enantioseparations of the profen NSAIDs. However, flobufen gave better enantioseparation on the vancomycin CSP. The better enantioresolution of the majority of profen derivatives on the achiral columns with vancomycin added to the mobile phase can be attributed in particular to the higher separation efficiency of this capillary chromatographic system. In addition, vancomycin dimers, formed in the mobile phase, seem to offer a better steric arrangement for stereoselective interaction to these analytes than the vancomycin bonded on the CSP. These substantial differences in the CS structure significantly influence the chiral discrimination mechanism.

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“…(1) describe the properties of the separation system; they are defined as the difference in the properties of the stationary and mobile phases [14][15][16][17][18][19][20][21][22]. Coefficient v is determined by the cohesive energy of the mobile and stationary phases and reflects the effect of dispersive interactions.…”

Section: Introductionmentioning

confidence: 99%

Application of solvation model to prediction of the solute retention in liquid chromatography over a wide range of mobile-phase compositions

Jirkal

Machovcová

Ševčı́k³

2016

Acta Chromatographica

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Summary.Possibilities have been studied of using a solvation model to predict the retention behavior of solutes in liquid chromatography mobile phases of water-acetonitrile and water-methanol with the organic solvent content varying from 1 to 100 vol%. Twenty-one test solutes, both aliphatic and aromatic compounds, have been selected on the basis of two-level factorial designs. Using the multiple linear regression analysis, regression coefficients, which are characteristics of the stationary and mobile-phase system, were calculated for different mobile phases in the solvation model. Regression coefficients have been used for the prediction of the retention behavior. Unbiased results have been obtained by using two sets, one training and the other the testing set. The predicted retention has been compared with the experimental data. The methanol-water system provided good results at low and medium methanol concentrations; the retention prediction was unsatisfactory for mobile phases containing more than 90% of methanol. The acetonitrile-water system yielded similar results, but the retention prediction ceased to be at acetonitrile concentrations greater than 80%. The retention has primarily been determined by cohesive and acid-base interactions. The dependences of the regression coefficients on the mobile-phase composition were similar for the acetonitrilewater and methanol-water systems.

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Characterization of reversed-phase columns using the linear free energy relationship

Cited by 66 publications

References 58 publications

Characterization of HPLC packings

Characterization of HPLC packings

Vancomycin as chiral selector for enantioselective separation of selected profen nonsteroidal anti‐inflammatory drugs incapillary liquid chromatography

Application of solvation model to prediction of the solute retention in liquid chromatography over a wide range of mobile-phase compositions

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