Enantioseparation of tartaric acid by ligand‐exchange capillary electrophoresis using contactless conductivity detection

Abstract

A method for the determination of tartaric acid enantiomers using CE with contactless conductivity detection has been developed. Cu(II) as a central metal ion together with L-hydroxyproline were used as a chiral selector, the BGE was composed of 7 mM CuCl2, 14 mM trans-4-hydroxy-L-proline, and 100 mM ε-aminocaproic acid; the pH was adjusted to 5 by hydrochloric acid. Separation with a resolution of 1.9 was achieved in 9 min in a polyacrylamide-coated capillary to suppress the EOF. Various counterions of the BGE were studied, and migration order reversal was achieved when switching from ε-aminocaproic acid to L-histidine. With detection limits of about 20 μM, the method was applied to the analysis of wine and grape samples; only L-tartaric acid was found.

Contactless conductivity detection for analytical techniques—Developments from 2012 to 2014

“…Fatty acids were determined in margarine and vegetable oil samples using conventional CZE and nonaqueous CE . The separation of the enantiomers of tartaric acid in wine and grapes were carried out by ligand‐exchange CE . Eight biogenic amines (e.g., spermine, spermidine, putrescine, cadaverine, etc.…”

Improving the sensitivity in chiral capillary electrophoresis

“…In addition to improve the method sensitivity by means of the above‐mentioned strategies, an attractive approach is to use alternative detection systems as those grouped in Table . This table shows that in the last years most works employed either fluorescence or MS detection systems, whereas only a work described the use of a contactless conductivity detector . This detection system is well known for its low baseline noise, low cost, and its applicability in miniaturized devices .…”

Chiral separation of disease biomarkers with 2‐hydroxycarboxylic acid structure

“…Different studies have approached the enantioseparation of 2-hydroxycarboxylic acids. Some of them are ligand exchange CE [19][20][21], ligand exchange LC [22], GC analysis after derivatization [23], LC after derivatization [24], direct LC by using macrocyclic antibiotic chiral stationary phases (CSPs) [25][26][27], and quinine-or quinidine-derived CSPs [28][29][30][31][32][33], amongst others.…”