High performance capillary electrophoresis - T.E.A.M.

4.3.7.4 Confirming peak identity
Migration time or mobility measurements are often insufficient
to confirm peak identity. Spectral analysis and library
searching is a useful way to accomplish this. Spectra at the
peak apex can be acquired automatically with the diodearray
detector. The spectra can then be compared with
those stored in a library. With automated comparison a
match factor is calculated to give the statistical probability
of peak identity. The spectral libraries can easily be built
up by the user. In addition, the vast collection of libraries
compiled from liquid chromatography can be used.
Additional detail regarding the use of DAD can be found in
the Agilent Technologies primer entitled Applications of
diode-array Detection in HPLC.
Instrumentation/Operation
4.4 Liquid handling
Liquid handling in CE is important both to maintain high
separation efficiency, automation, and overall experimental
flexibility. Such a system can be considered to include an
autosampler, fraction collector, buffer replenishment system
and buffer leveling system.
4.4.1 Autosampler
In CE an autosampler has two functions. It should transport
both the sample vials and buffer vials to the capillary ends.
For automated method development, usually a single
sample vial and numerous buffer vials (each pair containing
a different buffer composition) are used. Conversely, for
routine analysis, numerous samples but only a single buffer
is used. Thus it is important to have a high vial capacity and
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