GE AxiChrom 50 Operating Instructions Manual page 146

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