ISSN:
1612-1112
Keywords:
Gas chromatography
;
Liquid crystals
;
Internal and external NO2 compounds
;
Transition temperature
;
Analytical properties
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Summary Thermal and analytical properties of two liquid crystals containing internal [2-nitro, 3-methyl 4-(4-heptylbenzoyloxy) 4′-methylazobenzene] and external NO2 [2,3-dimethyl 4-(4-heptylbenzoyloxy) 4′-nitroazobenzene] have been investigated by gas chromatography. Transitions temperatures are determined by inverse gas chromatography using standard columns. Good agreement with values determined by differential scanning calorimetry are found. Analytical capabilities of the two liquid crystals are shown in glass capillary columns. Compared to examples in the literature, the crystals used separated different kinds of solutes. In addition, high molecular mass solutes were eluted at relatively low temperatures. Typical separations are observed for hydrocarbon positional isomers, aromatic hydrocarbons, geometric isomers, and volatile aroma compounds. Comparison between the performance of internal and external, NO2-liquid crystals is made.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02290272
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