Premium
Open tubular columns with mixed‐mode reversed‐phase and weak anion‐exchange stationary phase for capillary electrochromatography
Author(s) -
Lei Jie,
Zhang Xiangmin
Publication year - 2013
Publication title -
journal of separation science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.72
H-Index - 102
eISSN - 1615-9314
pISSN - 1615-9306
DOI - 10.1002/jssc.201201146
Subject(s) - silanol , capillary electrochromatography , chemistry , phase (matter) , electrochromatography , chromatography , surface modification , capillary action , amine gas treating , analytical chemistry (journal) , ion exchange , monolith , ion , capillary electrophoresis , materials science , organic chemistry , catalysis , composite material
Columns for open tubular capillary electrochromatography, coated with a mixed‐mode ( RP /ion‐exchange) stationary phase, were prepared by using the sol–gel method. The synthetic procedure was optimized by changing the ratios of tetraethoxysilane, octyltriethoxysilane, and 3‐aminopropyltriethoxysilane in the initial sol. SEM studies reveal that a coating with about 400 nm thickness can be obtained. The inner surface properties of these capillaries were probed by measuring the EOF as a function of pH. The surface of this stationary phase contains octyl, amine, and residual silanol moieties; the amine and silanol groups determine the net charge on the inner surface of the capillary and can produce a switchable EOF (anodal/cathodal). The performances of the columns were evaluated by open tubular capillary electrochromatography using a wide range of compounds (polycyclic aromatic hydrocarbons, aromatic acids, and aromatic amines).