High performance capillary electrophoresis - T.E.A.M.
High performance capillary electrophoresis - T.E.A.M.
High performance capillary electrophoresis - T.E.A.M.
Create successful ePaper yourself
Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.
Modes<br />
Mode<br />
Capillary zone<br />
<strong>electrophoresis</strong><br />
Micellar<br />
electrokinetic<br />
chromatography<br />
Capillary gel<br />
<strong>electrophoresis</strong><br />
Isoelectric<br />
focusing<br />
Isotachophoresis<br />
Table 8<br />
Modes of CE<br />
Basis of<br />
separation<br />
Free solution<br />
mobility<br />
Hydrophobic/<br />
ionic interactions<br />
with micelle<br />
Size and charge<br />
Isoelectric point<br />
Moving<br />
boundaries<br />
The versatility of CE is partially derived from its numerous<br />
modes of operation. The separation mechanisms of each<br />
mode are different and thus can offer orthogonal and<br />
complementary information. The basic methods encompassed<br />
by CE include <strong>capillary</strong> zone <strong>electrophoresis</strong> (CZE),<br />
micellar electrokinetic chromatography (MEKC), <strong>capillary</strong><br />
gel <strong>electrophoresis</strong> (CGE), <strong>capillary</strong> isoelectric focusing<br />
(CIEF), and <strong>capillary</strong> isotachophoresis (CITP).<br />
The separation mechanisms of each mode are illustrated in<br />
figure 21 and described in table 8. For the most part, the<br />
different modes are accessed simply by altering the buffer<br />
composition. Each mode is described below, with emphases<br />
on basic operation and relevant applications.<br />
Figure 21<br />
Illustration of zonal, IEF and ITP <strong>electrophoresis</strong><br />
Zone <strong>electrophoresis</strong><br />
a)<br />
t = 0<br />
t > 0<br />
IEF<br />
Capillary filled with mixture of sample and ampholytes<br />
b)<br />
t = 0<br />
Low pH<br />
pH gradient<br />
<strong>High</strong> pH<br />
t > 0<br />
ITP<br />
c)<br />
T<br />
L<br />
t = 0<br />
T<br />
L<br />
t > 0<br />
46
Change language