Fused silica capillaries with an i.d. of 50 and 75 mm are chemically modifi
ed by the silanization/hydrosilation method to attach organic moieties for
use in electrokinetic chromatography. An etching process was utilized to in
crease the surface area of the capillary inner wall. A comparison of Si-C b
onded capillary columns to those obtained by conventional organosilanizatio
n (Si-O-Si-C) bond was performed. The etched capillaries after chemical mod
ification are shown to have an anodic electroosmotic flow (EOF) below pH 4.
5 while the bare modified capillaries show a cathodic EOF at all pH's studi
The use of these etched chemically modified capillaries eliminates the need
for frits and the difficulties associated with packed capillaries such as
bubble formation. This open tubular approach to CEC is also suitable for an
analysis of a number of different types of basic compounds.