P. Sun et al., CHITOSAN COATED CAPILLARY WITH REVERSED ELECTROOSMOTIC FLOW IN CAPILLARY ELECTROPHORESIS FOR THE SEPARATION OF BASIC DRUGS AND PROTEINS, The Journal of microcolumn separations, 6(4), 1994, pp. 403-407
An enhanced surface coating method was developed for capillary electro
phoresis (CE) using the natural polymer chitosan. The cationic propert
y of chitosan at pH below 6.5 created a reversed electroosmotic flow (
EOF) in the capillary. The EOF changed significantly with the run buff
er pH at values below 4.0, with less pH dependency at values in the pH
range of 4.0-5.5. The new coating exhibited good performance reproduc
ibility. The relative standard deviation (RSD) of EOF was 0.77 %. The
EOF changed an average of 2.4 % after 10 b normal use. The EOF started
to change significantly after a constant electric field (300 v cm-1)
had been applied for 20 h. This capillary with a reversed EOF can be u
sed to reduce the solute-wall interaction problem for separations of b
asic analytes, for example, separations of positively charged proteins
and basic drug enantiomers.