Bio-Rad Aminex Organic Acid and Alcohol Analysis Columns User Manual
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To avoid contaminating the detector flow cell when cleaning or regenerating the
column, disconnect the tubing between the column and the detector. Allow the
appropriate solvent to pass directly to waste.
6.3 Reconverting a Column to its Original Ionic Form
Ionic exchange resins shrink and swell with changes in ionic form. If a new buffer
with the wrong counterion is used, the column may be converted to a new form,
with accompanying resolution and back pressure problems. In most, but not all
cases, the column may be reconverted to the original form by the following
procedure.
1.
Reverse the flow direction and backwash the column at 0.1 ml/min for at least
4 hr in the appropriate regenerating solvent.
2.
Return the column to original operating conditions.
6.4 Topping Off a Column Bed
In rare cases, some bed settling may occur in use. More frequently, serious over
pressure may cause irreversible bed collapse. The resulting void space at the
column head can often be topped off with material from an old column or with
material obtained from Bio-Rad Laboratories. In order to be assured that the
column problem is due to a void in the inlet side of the column, run an unretained
compound (sample), and look for tailing on the resulting peak. If you are unsure,
then consult Technical Services at 1-800-424-6723, or contact your Bio-Rad
office.
1.
Disconnect the column from the HPLC system.
2.
Store the column at 4°C for 3 hr. Do not freeze.
3.
Loosen the nut on the column inlet fitting, which is located at the column end
opposite to the flow arrow.
4.
Using a clean spatula, carefully pack resin of the same type and ionic form
(obtained from an old column or directly from Bio-Rad) into any apparent void
space. Resin should be packed into a shallow cone 1 mm or so above the
column end.
5.
Replace the end fitting and tighten the nut leak tight.
6.
Return the column to original operating conditions.
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