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Competitive binding of a Tris run buffer with chiral crown ether in chiral capillary electrophoresis
Author(s) -
Cho Seung Il,
Jung Hyunsook,
Chung Doo Soo
Publication year - 2000
Publication title -
electrophoresis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.666
H-Index - 158
eISSN - 1522-2683
pISSN - 0173-0835
DOI - 10.1002/1522-2683(200011)21:17<3618::aid-elps3618>3.0.co;2-4
Subject(s) - tris , hydroxymethyl , chemistry , capillary electrophoresis , enantiomer , amine gas treating , electrophoresis , binding constant , crown ether , citric acid , chromatography , protonation , buffer (optical fiber) , equilibrium constant , ether , inorganic chemistry , organic chemistry , binding site , computer science , ion , telecommunications , biochemistry
In capillary electrophoresis of primary amine racemates using (+)‐(18‐crown‐6)‐tetracarboxylic acid (18C6H 4 ) as a chiral selector, chiral recognition emanates from the differences in the complex formation between 18C6H 4 and the two protonated amine enantiomers. The presence of buffer constituents such as tris(hydroxymethyl)aminomethane (Tris) or Na + , capable of forming complexes with 18C6H 4 , is thus detrimental to the chiral separation of primary amines. Such a competitive binding of buffer constituents was studied by comparing the electrophoretic mobilities of racemic analytes obtained in Tris/citric acid and triethylamine/citric acid buffers. We developed a simple fitting method to determine the competitive binding constant and applied it to the Tris buffer system. The competitive binding constant of Tris with 18C6H 4 obtained at pH 3.0 was 27 ± 4.