03-914978-00:1
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Troubleshooting
Correction of Solvent Tailing or Broadening Problems
Symptom Solution
Poor column installation
resulting in dead volume
in the injector
Reinstall the column in the injector. Check the column seal
with the insert in the SPI/1079 (on-column). Make sure you
have a good cut on the column by examining the column
under magnification. Check the 1077/1078/1079 injector for
insertion depth.
Solvent flashing in hot
injector (usually 1077,
1078 or 1079)
Reduce the injection speed for the hot injectors. If possible,
reduce the injector temperature. If you are using sandwich
injection, reduce the solvent plug to 0.5
µ
L.
Incorrect temperature
control using
programmable SPI or
1079.
A typical setting for the SPI is 20 °C below the solvent boiling
point. The column temperature is set at the solvent boiling
point. Hold the column at this temperature until SPI has
finished heating (usually about 2 min).
Septum purge line is
plugged
Check that the septum purge flow is 0.5 mL/min for a SPI
with a 10-psi head pressure, 2 mL/min for a 1077 or 1078
and 3.5-4.5 mL/min for 1079 with a 10-psi head pressure. If
necessary, change the septum purge frit or adjust the valve
setting (depending on your injector configuration).
Injector is not purged
properly following
splitless injection
For a splitless injection, the vent flow should be at least 70
mL/min. The injector should be switched to the split mode 30
to 90 sec after the injection.
Correction of Tailing Sample Peaks for Particularly
Active Components
Symptom Solution
Active sites in the
injector insert or liner
Change or clean the injector insert. If necessary, silanize it.
Active sites or degraded
phase present in the
column
Remove the front 15 cm of the column and reinstall it. If the
retention times are changing, or if cutting the column does
not fix the problem, replace the column.
Correction of Low Response and Severe Tailing with
High Boiling Point Compounds
Symptom Solution
Injector not hot enough
to vaporize high boilers
Increase the temperature of the injector
High levels of column
bleed masking
component peaks
Condition the column at 30 °C below its maximum operating
temperature (320 °C for DB-5). Switch to a high temperature
column, (e.g., the SGE HT5), if conditioning does not help.
High levels of silicone or
other contamination are
coated on the ion trap
surfaces
Clean the ion trap as outlined in Maintenance Section.
Check Contamination Table for listing of potential
contamination.
Insufficient vaporization
of the higher boiling
point components
Lower the injector temperature and the injection speed.
Check that the graphite ferrule in the 1077 or 1078 is free of
cracks, and that the septum support is tight.
Trap temperature is too
low
Increase the trap temperature in increments of 20 °C.
