Helpful Hints For Capillary Electrophoresis
Improving Signal to Noise Ratios
When signal to noise is too high to produce reproducible results, the settings on your instrument can sometimes be
changed to give you acceptable results. You should consult your manual or contact your instrument company for a list
of suggestions.
A real life example we experienced was with a lab that was having difficulty with integration of peak area while
using CElixirOA (inverse detection and polarity) looking at organic acids and anions.
This customer was using a new Beckman MDQ instrument and contacted Beckman technical support with the problem.
Their suggestion was to replace the aperture clip in the detector with a 100 x 800 micron size aperture (over the
capillary window) instead of the 100 x 200 micron size that they were using.
They did that (and also replaced the capillary) and it made a world of difference in the light throughput and
reduction of noise. The baseline threshold was 75, well below the 400 they were experiencing and the integration
parameters for the method were working much better after the change using the CElixirOA5.4 buffer kit.