ISSN:
1612-1112
Keywords:
Column liquid chromatography
;
Porous graphite
;
Chiral stationary phase
;
Copper complexation chromatography
;
Amino acids
;
Hydroxy acids
;
Adsorbed stationary phases
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Summary A new type of chiral stationary phase has been prepared by coating porous graphite with a near-monolayer of an adsorbed enantiomeric modifier which then acts as an adsorbed stationary phase. The most effective modifiers are L- or D-isomers of N-(2-naphthalene-sulphonyl)-phenylalanine (NS-Phe). Conveniently 80% of monolayer coverages, corresponding to 1.2 μmol m−2, are achieved by adsorption of NS-Phe from methanolic solution. Enantiomeric separations by complexation with cupric ion show base-line resolution of α-amino and α-hydroxy acids with separation factors up to 2. Identical separations are achieved with chiral phases made from the L- and D-isomers of NS-Phe except that the elution orders of enantiomers are inverted. Reduced plate heights are around 5 and the adsorbed chiral phases are extremely stable, retention ratios being unchanged after passage of 7000 column volumes of eluent. A mechanism of retention is proposed, which fits the experimental observations.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02274600
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