THE SEPARATION OF POSITIONAL ISOMERS BY CAPILLARY ELECTROCHROMATOGRAPHY

Autor: Lili Zhou, Kelly A. Newton, Richard Thompson, Jean Wyvratt, Bruce D. Johnson, Dean Ellison
Rok vydání: 2001
Předmět:
Zdroj: Journal of Liquid Chromatography & Related Technologies. 24:755-771
ISSN: 1520-572X
1082-6076
DOI: 10.1081/jlc-100103408
Popis: The feasibility for separation of positional isomers using capillary electrochromatography (CEC) was investigated. Two groups of neutral isomers, trifluoroacetophenone and bromobenzonitrile, were separated by CEC. Effects of selected parameters, such as mobile phase pH, ionic strength, temperature, organic modifier, buffer type, diluent type, voltage, and column length, were studied using bromobenzonitrile isomers to elucidate the separation mechanisms. In parallel, the separation of the isomers was also performed by high-performance liquid chromatography (HPLC) to serve as a comparison. It was found that the retention time behavior as a function of acetonitrile concentration in CEC was similar to that observed in HPLC. The effect of mobile phase pH has a greater impact with CEC than with HPLC due to the change in electroosmotic flow. The effect of temperature with liquid chromatography showed a linear Van't Hoff plot, while deviations from linearity were noted with CEC. The optimized CEC method was valid...
Databáze: OpenAIRE
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