Dynamic Coating for Capillary Electrophoresis
What Is CElixir-pH & how does it work?
Click here to view an animated graphical presentation of the Double Layer, Dynamic Coating for CZE.
CElixir is a patented1, double layer, dynamic coating system that
will make your CZE more reproducible. CElixir makes CZE useful in the pH range
of 1.0 to 9.2.0 in your lab with astonishing speed and precision. Unlike traditional
CZE, the two ionic solutions of CElixir will produce very robust EOF allowing
you to develop methods that are most optimal for your samples. You can now select
the pH where your analytes are most ionized or at or below your samples pK. Selectivity,
efficiency, speed and precision are now available to you with CZE.
The two polyionic solutions of CElixir are applied to a bare fused silica
capillary producing a very stable polymeric coating on the wall. First the cationic,
polymer of the Initiator Solution(A) binds to the ionized silanol sites of
the capillary wall. Then the anionic polymer of the Accelerator Solution(B),
with a vast excess of negative charge, is added. Thus, there is an increase in the
negatively charged sites relative to the bare fused silica wall that is always fully
charged. Most importantly, however, is that both the exposed polymer layer (negatively
charged) and the base polymer layers are washed off between runs by a NaOH solution
rinse. A virgin layer of both polymers is replaced before each analysis. This gives
previously unheard of reproducibility independent of source or age of the bare fused
Reproducible CZE methods from run to run, capillary-to-capillary
or instrument-to-instrument are now possible with CElixir.
How does it work?
Two solutions of CElixir are placed in three vials on your HPCE instrument
and are automatically applied to the capillary before and between runs. The CE practitioner
is no longer relying on the fused silica capillary as the main component of the
separation mechanism and EOF. The ionic polymers in CElixir now provide this
separation mechanism, making it “portable”, controllable and reproducible. The solutions
are always the same on any capillary you use and on any HPCE instrument that you
use and therefore the EOF and CZE conditions are always the same anywhere any time.
Low pH Yet High Flow Rate
Even at very low pH (as low as 1.7), CElixir has a very fast and reproducible
EOF. If you change the pH from run to run, the resulting change in EOF speed will
be negligible. This allows you to use pH as a solubility tool, a selectivity tool
or as a sample matrix option to retain the biological activity of your samples.
Since you are re-apply the coating before each run and the wall adsorption effects
are minimized the inherent capillary inconsistencies experienced at low pH are eliminated.
Precision, speed and reproducibility are increased over normal CZE.
Average Migration Time of Heroin Powder Using CElixir
This chart shows the results using seven different Capillaries with CElixir
at pH 6.6 and run six times each. This shows how stable the EOF and migration times
are using CElixir.
|Features of CElixir:
- Increases Precision of your EOF
- Increases Reproducibility of your HPCE
- Can be automated
- pH Independent
- Shifts Adsorption Equilibria
- Increases EOF Speed
- Lower Cost v. HPLC
- No Buffer Preparation Needed
- No Organics or Hazardous Material Used
|Benefits of CElixir:
- Makes Quantification of Peaks Easy and Reliable
- Gives you the confidence needed
- Easy to use, anyone in the lab can use it
- Use pH to control ionization of your sample for selectivity or to maintain biological
- Minimize Sample loss and increase reproducibility
- Shorter Analysis time, Increase lab throughput
- Save Money buying solvents and disposal costs
- Save Time and Increase Repeatability of Method
- Solutions are stable and safe and easily disposed of
1 Patent No. 5,611,903