## Abstract The solvation parameter model is used to characterize the solvent properties of 12 poly(siloxane) stationary phases of varied structure. Selectivity differences are explained in terms of differences in the cohesive energy of the solvents and their capacity for dispersion, dipoleβtype, h
Shape selectivity assessment of stationary phases in gas chromatography
β Scribed by Lane C. Sander; Manfred Schneider; Stephen A. Wise
- Publisher
- John Wiley and Sons
- Year
- 1994
- Tongue
- English
- Weight
- 786 KB
- Volume
- 6
- Category
- Article
- ISSN
- 1040-7685
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β¦ Synopsis
Abstract
Column selectivity is examined for a series of smectic liquid crystalline columns and is compared with methyl and C~18~ polysiloxane columns for the separation of polycyclic aromatic hydrocarbon (PAH) isomers. A set of extended and condensed solute probes is described that provides a sensitive indication of variations in column shape selectivity. Examples of shape selectivity differences are presented for smectic liquid crystalline columns and 5% phenyl polysiloxane columns using various PAH isomer sets. Variations in selectivity have been observed among different smectic liquid crystalline columns, and this problem appears more significant than for methyl polysiloxane columns. The selectivity ration for tetraphenylmethane and pβterphenyl provides a sensitive indication of column shape selectivity, with a change in elution order occurring between ordered (smectic liquid crystalline) columns and nonβordered (methyl polysiloxane) columns. Shape selectivity differences indicated by this test mixture are apparent for more complex PAH isomer mixtures. Despite stationary phase selectivity variability, smectic liquid crystalline columns offer considerable potential for solving difficult separation problems involving structured solutes.
π SIMILAR VOLUMES
Thermal stability and enantioselectivity of chiral polysiloxane staposition and purity of the polymer matrix, its functional groups, the chiral selector, and the pretreatment of the inner surface of the be prepared which may be used to 300 o c for short times. Crosslinking of the phases is achieved