Premium
Sample stacking for the analysis of catechins by microemulsion EKC
Author(s) -
Huang HsiYa,
Huang I.Yun,
Liang Hsinhui,
Lee Szetsen
Publication year - 2007
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/elps.200600413
Subject(s) - microemulsion , stacking , chemistry , chromatography , gallate , analyte , catechin , electrolyte , organic chemistry , polyphenol , nuclear chemistry , biochemistry , pulmonary surfactant , electrode , antioxidant
In this study, an on‐line concentration method, ASEI (anion‐selective exhaustive injection)‐sweeping technology which was coupled with microemulsion EKC (MEEKC), was used to analyze and detect six catechins ((−)‐epicatechin, (+)‐catechin, (−)‐epigallocatechin gallate, (−)‐epicatechin gallate, (−)‐epigallocatechin, and (−)‐gallocatechin). In addition to the effects of the buffer pH and electrolyte concentration on stacking, the compositions of microemulsion (types of oil phase, and types and levels of cosurfactant) also dominated the stacking effect of catechins. In MEEKC, the effect of the type of oil in microemulsion on separation mechanism is often unclear. This study had demonstrated that the oil type in microemulsion indeed altered the affinity of oil droplets with analytes. Finally, this proposed ASEI‐sweeping MEEKC method was able to detect trace level of catechins in food products that was not previously possible by a normal MEEKC method.