Bio-Rad Aminex Organic Acid and Alcohol Analysis Columns User Manual
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Section 4
Connecting the Column
Reduce the flow rate to 0.2 ml/min. Remove the end screws from the analytical
column and attach the outlet end of the guard column tubing to the inlet of the
analytical column. Connect the analytical column with the pump running at a slow
flow rate, to exclude any air from the column inlet. Pass approximately 20 ml of
degassed solvent through the column. When a new column is initially placed on an
LC system for use or testing, the column should be attached only at the inlet end
when introducing the mobile phase. This prevents particulates of packing (should
the frit have been broken in shipment) or air bubbles (if the column dried during
storage) from getting into the detector flow cell. When clear, bubble-free solvent is
flowing from the outlet end of the column, the column outlet may be attached to
the detector.
It is important that the tubing between the column and the detector be as short as
possible. Tubing with a small inner diameter (0.010 inch ID) should be used
between the injector and the column, and also between the column and detector.
Be sure to make provision for collecting and properly disposing of waste solvent.
Place the column in Bio-Rad’s Column Heater (catalog number 125-0425),
equipped with the appropriate inserts, after checking for leaks in guard column and
analytical column connections. Turn on the column heater and adjust the
temperature. Never heat the column without flow. Increase the flow rate only after
the column has reached the set temperature. Equilibrate the column with your
eluant. With gradient systems, use the starting eluant.
Be sure air does not get into the column. If there is reason to believe that it has,
reduce the column temperature, reverse the column direction, and allow the
solvent to flow slowly through the column until the air is eliminated. Be sure to
remove air from all system piping. Then reconnect the column correctly.
Note that all metal tube connections are of the compression screw (reverse nut)
type. A ferrule is compressed permanently against the tubing. To insure minimum
dead volumes, tighten the assembly of tubing, ferrule, and nut finger tight. Push
the tubing in until it bottoms firmly. Using a 1/4’’ wrench, tighten 1/4 turn. The
fitting only needs to be tight enough to seal; its lifetime will be diminished by
over-tightening.
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