Quantitative determination of straight and cyclic hydrocarbons in crystallized permethylated-beta-cyclodextrin inclusion complexes by static headspace-gas chromatography
P. Cardinael et al., Quantitative determination of straight and cyclic hydrocarbons in crystallized permethylated-beta-cyclodextrin inclusion complexes by static headspace-gas chromatography, J SEP SCI, 24(2), 2001, pp. 109-115
Static headspace-gas chromatography (HS-GC) method is used for determinatio
n of the stoichiometry of crystalline inclusion complexes of heptakis (2,3,
6-tri-Omethyl)-beta -cyclodextrin (TRIMEB) with methylcyclohexane, pentane,
cyclohexane, hexane, (-)alpha -pinene, and (+/-)-alpha -pinene. The 'Full
Evaporation Technique' (FET) with Multiple Headspace Extraction (MHE) measu
rements is realized in a straightforward manner on the solid material; this
appears to be the most convenient method for quantitative determination of
the guest/host ratio. As an interesting alternative, the 'solution approac
h' (sample dissolved in the solvent) is also performed by a single extracti
on with ethanol as solvent, which is sufficiently polar to dissociate these
complexes. TRIMEB forms stable 1:1 complexes with cycloalkanes or cycloalk
enes at room temperature and normal pressure. In contrast, the stoichiometr
y with n-alkane is different from ratio of 1:1 because this solid shows eff
lorescent behavior under the same conditions.