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Volume 46, Number 6
(November - December 2001) |
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Volume 46, Number 6
(November - December 2001) |
Chemometric Characterization of the RF Values of Alkaloids for Thin Layer Chromatographic Systems of the Type Polar Adsorbent - Multicomponent Eluent
by Monika Waksmundzka-Hajnos and Maria Gadzikowska
Department of Organic and Analytical Chemistry, Medical University, 6 Staszica Street, 20-081 Lublin, Poland
Key words: TLC, alkaloids, retention-eluent composition relationships, selectivity - RM1 vs RM2 correlations, silica, alumina, magnesium silicate
Chemometric characteristic of several alkaloids of various groups was
performed by the relationships of their retention coefficients RF
against modifier concentration in eluent. Retention of alkaloids was investigated
on silica layers using nonaqueous eluents containing of different amounts
of methanol in dichloromethane or using aqueous eluents (in pseudoreversed
phases) using methanol or acetonitrile as modifiers and 2% of glacial acetic
acid. For poorly separated compounds in such systems alumina and magnesium
silicate (Florisil) and dichloromethane - methanol mixtures as eluents
were used. Selectivity of separation was analyzed by correlation diagrams
RM A1 vs RM Si
and RM Si vs RM Florisil
for data obtained in nonaqueous systems. Presented results as RF
vs C% plots or RM1 vs RM2
diagrams permit to choose selective systems for the separation of particurar
groups of substances and enable identification and chemometric cheracterization
of investigated alkaloids.
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