Action
Comment
Problem
•
Compress the bed further and retest
before repacking the column with a
higher Packing Factor.
Bed too loosely packed
causing a gap between
chromatography medium
and adapter.
Poor stability when
repeating packing
evaluation. Increased
tailing.
•
Re-equilibrate the column. Evaluate the
packing again.
Column not properly
equilibrated before packing
evaluation.
Poor stability when
repeating packing
evaluations. Decreased
tailing.
•
Repack the column with a lower Packing
Factor.
Bed packed too densely.
Cracks present at the
beginning get worse.
Poor stability when
repeating packing
evaluation. Increased
leading.
•
Re-equilibrate the column. Evaluate the
packing again.
Column not properly
equilibrated before packing
evaluation.
Poor stability when
repeating packing
evaluation. Decreased
leading.
•
Repack the column with a higher or
lower Packing Factor.
Bed packed too densely or
too loosely.
Poor stability when
repeating packing
evaluation. Decreasing
number of plates.
•
Ensure the equipment is the same or
identical to your test routine or Standard
operating procedure, SOP.
Extra volume in the system,
e.g. new tubing (longer,
shorter or different diameter)
affects peak position and
HETP.
Peak moves over
several HETP (Height
Equivalent to a
Theoretical Plate)
evaluations. Retention
times change.
•
Use appropriate test molecule and con-
ditions, e.g. use acetone or 0.8 M NaCl
as sample in 0.4 M salt liquid.
Test molecule is excluded by
the chromatography
medium under the
conditions used, e.g. NaCl for
ion exchange chromatogra-
phy, or chromatography
medium in water as running
liquid.
HETP values
unrealistically high
(number of theoretical
plates too low).
146
AxiChrom 50, 70 and 100 columns Operating instructions 28-9331-08 AG
7 Troubleshooting
7.1 Performance
