Bio-Rad BioLogic QuadTec™ Detector and Components User Manual
Page 50
Problem
Possible Cause
Suggested Solutions
Excessive pump
Air bubbles trapped in
pulsations exhibited
the pump heads can
as a sinusoidal
produce exaggerated
baseline or “regular
pulsation, which appear
noise” on the
as a noisy baseline.
detector baseline.
Lamp test
Lamp needs
performed from
burning in.
QuadTec Setup
Signal menu gives
error message
“E INT”.
Baseline noise
Noise spikes can also
continues when
be caused by external
pumps are
environmental influences.
turned off.
UV trace will not
If no air bubbles are
zero.
present in the flow cell,
check that the cell itself
is clean both internally
and externally.
Drifting baseline.
Non-homogeneous
solvent due to poor
mixing or flow rate
variation.
Slow column
equilibration.
If drift is due to a higher
absorbance, suspect that
UV absorbing material
may be leaching from the
column.
TROUBLESHOOTING
SYSTEM INSTALLATION AND SETUP
6-3
1.
Purge the pump heads to remove trapped air
bubbles. See the Troubleshooting section of the
BioLogic DuoFlow instruction manual.
1.
Leave the lamp burning for several hours (up to
24).
2.
Retest periodically from the Setup menu.
3.
If error message persists, contact Bio-Rad
Technical service at 1-800-4-BIORAD.
1.
If the spikes occur at regular intervals (for example,
once every 20–30 sec), check for the presence of
heating baths, drying ovens, or other heating
devices on the same electrical circuit or in close
proximity to the BioLogic DuoFlow system. Turn off
these devices to see if the problem goes away.
1.
Clean the interior of the flow cell using the
procedure outlined in the Maintenance chapter.
2.
Condensation may occur on the exterior windows
of the flow cell when moving the optics unit from
the lab to a cold room and vice versa. Always allow
an equilibration period to compensate for such
temperature effects.
1.
Check flow rates of both pumps; recalibrate if
needed by selecting Calibrate Gradient Pump from
the Utilities drop-down menu.
2.
Some ion exchangers are slow to equilibrate
especially if just sanitized. Allow a longer
equilibration period.
3.
To confirm this, remove the column and run DI
water or an aqueous non-absorbing buffer. If the
baseline is stable, then the column is suspect.
Consult the column’s user manual for cleaning
procedures.