BUCHI Cartridge C-670 - Manual (Page 13)

BÜCHI Cartridger TM C-670
11
5 Operation
5.2.1 Selecting the stationary phase
The stationary phases to be packed must be dry and must
have a very uniform particle size range, e.g. clumped starting
material is unsuitable. The permissible particle sizes for packing
lie between 30 and 200µm. Modified phases can also be used
in this particle size range (C18, C8, C4, ...). Smaller particles
cannot be reliably packed.
Do not use phases containing fine dust particles that can
penetrate the lungs (particle size <10µm). These can endanger
your health.
Use DC plates to test which stationary phases are best suited
for your separation. Modified silica gels can also be packed
with the Cartridger (C18, C8, C4, NH2...).
5.2.2 Filling the stationary phase
Remove the black function lid and slowly empty your stationary
phase into the glass container. Please be sure not to overfill
the vessel (see the marking on the glass).
5.2.3 Fluidization of the stationary phase
The fluidization is based on a flow of gas (or air) through the
stationary phase. A frit is integrated into the bottom of the
glass vessel. The optimal gas flow is dependent upon the
grain size of the silica gel and can be set very precisely on the
right side using a needle valve. Be sure to close the needle
valve completely when using the Cartridger for the first time.
Fill the glass vessel and open the air supply to the Cartridger.
Next, slowly open the needle valve until the first air bubbles
appear on the surface of the gel. Inspect the fluidization with
a spatula. It should be possible to move the spatula through
the fluidized gel without resistance. However, the gel shouldn’t
bubble, meaning that the gel should have an even, calm
surface.
Once the needle valve has been set, it need no longer be
adjusted as long as the admission pressure and the stationary
phase remain the same. At the end of the packing process
you need only shut off the main gas flow. Please turn on the
gas supply slowly prior to the next packing procedure.
Figure 5.1: Glass vessel with level indicator
Figure 5.1: Needle valve for fine regulation of gas flow