Solvent selectivity in the liquid chromatographic separation of polystyrene oligomers on silica

Mourey, Thomas H.; Smith, Gary A.; Snyder, Lloyd R.

doi:10.1021/ac00275a005

Cited by 38 publications

(11 citation statements)

References 31 publications

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“…In previous work by Mourey et al, [29] normal-phase LSC was employed for the separation of diastereomers of low molecular weight oligostyrenes. They used two 4.6 mm Â 250 mm serially coupled silica columns running a linear gradient, increasing at 0.1%/mL from 89% to 11% n-hexane/dichloromethane at a flow rate of 1.0 mL/min.…”

Section: Resultsmentioning

confidence: 99%

Ultra‐High Resolution Separation of Diastereomers on Carbon Adsorption Stationary Phases

Milroy

Dennis

Shalliker

2007

Journal of Liquid Chromatography & Related Technologies

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Reversed-phase adsorption liquid chromatography was used to successfully resolve diastereomers in a complex mixture of low molecular weight polystyrene oligomers. The separation was achieved by incorporating a two-dimensional liquid chromatography system where the polystyrene oligomers were transported from the first dimensional column, a C 18 , to an adsorbent phase in the second dimension, a carbon clad zirconia (CCZ) column. Using this system up to 46 diastereomers, each consisting of eight configurational repeat units, were able to be resolved in ultra high separations.

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Section: Resultsmentioning

confidence: 99%

Ultra‐High Resolution Separation of Diastereomers on Carbon Adsorption Stationary Phases

Milroy

Dennis

Shalliker

2007

Journal of Liquid Chromatography & Related Technologies

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“…(8)(9)(10)(11)(12) Further dimensionality of the polystyrene may be described depending upon the classification of the types of stereoisomers that may be present within the oligomeric fractions, i.e., tacticity. One dimension of the sample is the variation in the molecular weight of each oligomeric unit, while a second dimension of the sample may be described by the stereoisomers that are present within each oligomeric fraction.…”

Section: Sweeney Wyllie and Shallikermentioning

confidence: 99%

The Separation of Stereoisomers From Oligomers of Low Molecular Weight Polystyrene on a Carbon Clad Zirconia Column Using a Reversed Phase Multidimensional HPLC System

Sweeney

Wyllie

Shalliker

2001

Journal of Liquid Chromatography & Related Technologies

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The two dimensional separation of low molecular weight polystyrene oligomers and stereoisomers was achieved using a liquid chromatographic system designed for 'heart-cutting' multidimensional chromatography. The first separation process incorporated a C18 column and a methanol mobile phase to separate the oligomers, whilst the second separation process utilised the change in selectivity associated with a carbon clad zirconia stationary phase and an acetonitrile mobile phase for the separation of the isomers. The two dimensional separation that was achieved using this automated system was comparable to the individual 2559 separations following manual sample manipulation in each individual separation step. Furthermore, the multidimensional LC system was shown to be highly reproducible in routine continuous operation over an eight hour period.

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“…Separations in which the enthalpic interactions dominate over the entropic exclusion have been reported in reversed phase [1 -9] and normal phase [6,10 -12] liquid chromatography, as well as supercritical-fluid chromatography. [10] Nevertheless, in all such cases the separation of isomers for the oligomeric fractions is dominated by the molecular weight of the oligomeric fractions, [1 -12] and the isomers elute within confined regions depending upon their molecular weight. These changes in chromatographic selectivity may allow isomeric components to be separated on the basis of their different stereochemistries.…”

Section: Introductionmentioning

confidence: 99%

“…Selectivity in a separation is not entirely independent of the solvent strength, but is a term used to define individual solvent characteristics that relate to aspects of the solute, rather than the solvent averaged group effects. [10,11] In all cases, the stereoisomer resolution is secondary to the molecular weight separation, and isomers are resolved within the distinct regions specific to that particular molecular weight. [15] In this triangle, solvents with similar attributes are grouped together, making it possible for the analyst to anticipate changes in selectivity.…”

Section: Introductionmentioning

confidence: 99%

Selectivity and the Separation of Isomers of Low Molecular Weight Polystyrenes

Gray

Sweeney

Dennis

et al. 2004

Journal of Liquid Chromatography & Related Technologies

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The separation of diastereoisomers of polystyrene has been investigated on carbon-clad zirconia (CCZ), C 18 , and diamond C18 stationary phases using eluents of widely different properties. Eluents were chosen according to their selectivity, solvent polarity index, and polymer solubility constants. Acetonitrile mobile phases in combination with CCZ produced the best diastereoisomer separations, however, when methanol was employed as the mobile phase, the separation profiles were very similar, except that retention was greatly increased. Retention and isomer separation decreased when isopropanol was employed. Surprisingly, some diastereoisomer separation was still apparent using the CCZ column and a 99% hexane/1% isopropanol mobile phase, although none was observed for the same solvent mixture on a C 18 column. Indeed, significant diastereoisomer separation was only obtained on the C 18 column-using acetonitrile as the mobile phase, but the resolution was far inferior to that observed on the CCZ column. The diamond C18 surface, which is a hybrid of C 18 and CCZ, gave separations that were intermediate between those of the parent surfaces, with enhanced molecular weight selectivity in comparison with CCZ, but slightly less discrimination on the basis of stereochemistry. Polystyrenes eluted unretained if either dichloromethane or tetrahydrofuran were used as the mobile phases on all stationary phases.

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Solvent selectivity in the liquid chromatographic separation of polystyrene oligomers on silica

Cited by 38 publications

References 31 publications

Ultra‐High Resolution Separation of Diastereomers on Carbon Adsorption Stationary Phases

Ultra‐High Resolution Separation of Diastereomers on Carbon Adsorption Stationary Phases

The Separation of Stereoisomers From Oligomers of Low Molecular Weight Polystyrene on a Carbon Clad Zirconia Column Using a Reversed Phase Multidimensional HPLC System

Selectivity and the Separation of Isomers of Low Molecular Weight Polystyrenes

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