Solvatochromic characterization of Silica-based stationary phases for liquid chromatography

Ryu, Young Kyun; Park, J. K.; Lim, H. J.

doi:10.1007/bf02490814

Cited by 11 publications

(7 citation statements)

References 52 publications

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“…This is the off-set of the QSRR equation and may be treated as the phase ratio of the system (U = V s /V m ). However, all the possible influences on retention, not covered by the QSRR equations, as well as the off-sets of the used descriptors, are summarized in the c term [32,33]. More difficult to interpret than the other regression coefficients, the c term values should be reported in QSRR studies as necessary if the retention of a non-tested analyte in the specific system was to be predicted.…”

Section: Regression Coefficients Of Qsrr Equationsmentioning

confidence: 99%

Quantitative structure‐retention relationships in reversed‐phase liquid chromatography using several stationary and mobile phases

Vonk

Lewandowska

Claessens³

et al. 2003

J of Separation Science

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Quantitative structure-retention relationships in reversed-phase liquid chromatography using several stationary and mobile phases Quantitative Structure-Retention Relationships (QSRRs) have been employed to study retention mechanism of Reversed-Phase Liquid Chromatography (RPLC). Two C 18 and two C 8 columns were used with mobile phases containing methanol, acetonitrile, and tetrahydrofuran in concentrations ranging from 40 to 90 (v/v)% in water. QSRR equations derived are generally characterized by a satisfactory quality of fit, although missing data or a low average retention can decrease the goodness-of-fit. In agreement with literature the most important retention descriptors appeared to be the analyte's molecular volume and its hydrogen-bond accepting basicity, but also the polarity/polarizability, hydrogen-bond donating acidity, and excess molar refraction showed statistical significance in several cases. Relatively small, but significant differences between the two C 18 stationary phases were observed. The differences between C 8 and C 18 column types were more pronounced. The influence of the mobile phase on regression coefficients is more difficult to interpret, because of adsorption of mobile phase constituents by the stationary phase. However, the importance of this partitioning of water and modifier is illustrated by the practically identical trends in b values for the three modifiers studied, while the trends in v values are significantly different. Principal component analysis of the QSRR regression coefficients demonstrated the prevailing role of the mobile phase for chromatographic properties of the RPLC systems studied as compared to the stationary phase.

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Section: Regression Coefficients Of Qsrr Equationsmentioning

confidence: 99%

Quantitative structure‐retention relationships in reversed‐phase liquid chromatography using several stationary and mobile phases

Vonk

Lewandowska

Claessens³

et al. 2003

J of Separation Science

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“…[1][2][3] Kamlet-Taft empirical solvent parameters have been established for this purpose, which allow a differentiated polarity assignment to be made. [4][5][6][7][8][9][10] The Kamlet-Taft equation, in its simple form, is given in eqn (1).…”

Section: Introductionmentioning

confidence: 99%

The dipolarity/polarisability of 1-alkyl-3-methylimidazolium ionic liquids as function of anion structure and the alkyl chain length

2010

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“…The dye DCBPI meets these requirements and has been shown not to exhibit any dye-specific behavior. 13,16 For DCBPI used in this work the following solvatochromic regression equation for the σmax in 9 pure solvents was obtained: Assuming that Eq. (3) for pure solvents also holds for aqueous PEG solutions, the α values for aqueous PEG solutions were computed as follows using the measured π* and σmax values for the solutions:…”

Section: Calculation Of the Solvatochromic Parametersmentioning

confidence: 99%

“…This method has been widely used to measure these properties of many types of solvents and solvent mixtures. [10][11][12][13][14][15][16] The π*, β and α values for neat liquid PEGs at room temperature have also been measured. Terminal hydroxyl groups of a PEG molecule can act as both an HB donor acid and an acceptor base, and oxyethylene repeating units can act as HB acceptor base.…”

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confidence: 99%

Dipolarity, Hydrogen-Bond Basicity and Hydrogen-Bond Acidity of Aqueous Poly(ethylene glycol) Solutions

et al. 2002

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The interaction of polymers with water has been extensively studied because of its scientific interest and importance in industrial applications.Poly(ethylene glycol) (PEG) has received a great deal of attention due to its unique properties pertinent to biomedical and biotechnical applications such as complete miscibility in water over a wide range of temperatures and molecular weights, very low toxicity, ability to precipitate proteins and nucleic acids and to form two-phase systems with aqueous solutions of other polymers. 1 Previous results by various techniques, such as complex permittivity, 2 partition, 3,4 potentiometric, 5 spectroscopic 6 measurements and thermal methods, 7 indicated that the physicochemical properties of water in polymer solutions are significantly changed, compared to those of pure water. Recently, Zaslavsky et al. 8 reported "polarity" of aqueous PEG solutions measured by a solvatochromic technique. 9 They measured the molar transition energy (ET) for the UV-VIS absorption band of Reichardt's betaine dye 9 in aqueous solutions of PEGs of various molecular weight (MW) at different concentrations, and observed that the polarity of aqueous PEG solutions, represented by ET, decreased with increasing the MW and concentration of PEGs. It has been suggested that the polarity decrease is due to the structuring action of PEG on water and that the observed solvatochromic effects are due to a change of solvent properties produced by the presence of polymer molecules, not due to a direct interaction of the dye with the polymer. 5,8 It is well known that ET is a composite characteristic that actually responds to changes in both a solvent's dipolarity/polarizability and a solvent's hydrogen bond (HB) donor acidity strength. 10,11 This suggests that the ET values alone can not clearly explain whether the presence of PEG molecules in water cause both of the dipolarity/polarizability and HB donor acidity of water or only one of these two properties to be altered. Water is HB basic as well as dipolar and HB acidic.11 In order to fully understand the effect of PEG on water we thought it is important to measure the HB acceptor basicity as well as the dipolarity/polarizability and HB donor acidity of the water in the presence of varying concentration of PEG.In the present work, we used the Kamlet-Taft solvatochromic comparison approach 10 to study dipolarity/polarizability (π*), HB acceptor basicity (β) and HB donor acidity (α) of aqueous PEG solutions. This method has been widely used to measure these properties of many types of solvents and solvent mixtures. [10][11][12][13][14][15][16] The π*, β and α values for neat liquid PEGs at room temperature have also been measured. Terminal hydroxyl groups of a PEG molecule can act as both an HB donor acid and an acceptor base, and oxyethylene repeating units can act as HB acceptor base. PEG molecules with these moieties are certainly dipolar. These properties of neat liquid PEG might be useful in understanding how PEG molecules affect the properties of water in...

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Solvatochromic characterization of Silica-based stationary phases for liquid chromatography

Cited by 11 publications

References 52 publications

Quantitative structure‐retention relationships in reversed‐phase liquid chromatography using several stationary and mobile phases

Quantitative structure‐retention relationships in reversed‐phase liquid chromatography using several stationary and mobile phases

The dipolarity/polarisability of 1-alkyl-3-methylimidazolium ionic liquids as function of anion structure and the alkyl chain length

Dipolarity, Hydrogen-Bond Basicity and Hydrogen-Bond Acidity of Aqueous Poly(ethylene glycol) Solutions

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