Electroosmotic solvent flow has been demonstrated in planar chromatography
media. The application of a 800 V cm(-1) field along conventional silica th
in-layer chromatography plates has been shown to give solvent migration rat
es of 0.039 and 0.210 cm s(-1) with ethanol and acetonitrile, respectively.
Electroosmotic elution has been applied to the separation of pirimicarb an
d a number of related compounds by planar electrochromatography. The elutio
n characteristics of these compounds were similar to those obtained by conv
entional thin-layer chromatography, yielding the same elution sequence, but
more rapidly. Whilst these compounds are separated by using conventional t
hin-layer chromatography, they require an elution time of ca. 18 min and co
mparable electrochromatographic separations can be achieved electroosmotica
lly in only 90 s; this corresponds to a 12-fold increase in elution rate. R
educed band-broadening is also evident with the electrochromatographic elut
ion. (C) 1999 Elsevier Science B.V. All rights reserved.