ISSN:
1040-7685
Keywords:
capillary column gas chromatography
;
nitrophenyl polysiloxanes
;
stationary phases
;
Chemistry
;
Analytical Chemistry and Spectroscopy
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Nitrophenyl-, nitrophenylethyl-, dinitrophenylethyl-, and methoxynitrophen- ylethyl-substituted polysiloxanes (25-50% substitution) have been synthesized and evaluated as stationary phases in capillary column gas chromatography. Phases with 25% substitution and with ethylene spacers between the phenyl substituents and the polysiloxane backbone were found to provide high efficiencies, moderate thermal stabilities, and useful selectivities. Without flexible hydrocarbon spacers, the station- ary phases exhibited poor efficiencies. The 50% substituted phases generally provided narrower operational temperature ranges and lower efficiencies, and they were more difficult to immobilize by free radical crosslinking. Several methods of immobilization were evaluated, and a dynamic procedure with dicumylperoxide (DCP) was found to produce the best results for these nitrophenyl-containing phases. The enhancements in polarity resulting from the resonances of the nitrophenyl substituent groups pro- vided unique selectivities for specific applications involving aromatic compounds. The dinitrophenyl-containing phases showed, in addition, selectivity based on charge transfer complex formation.
Additional Material:
7 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/mcs.1220010610
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