User`s guide

Troubleshooting
365
cannot be cleared by switching the ATD off and then on again,
contact your PerkinElmer service engineer.
If you have encountered a tube or trap leak and fault, the TD or ATD
will attempt to test three tubes. If three consecutive tubes fail at
either the tube or the trap, then a fatal error is generated. Refer to the
troubleshooting instructions in Instrument Fault Conditions on page
352.
Peak Broadening or Splitting
The chromatographic peaks represent the distribution of molecules
in a band as it elutes from the column, the overall broadness being
conveniently measured in terms of the width of the peak. A number
of independent factors, such as temperature and column retention
processes, contribute to the dispersion of molecules in a band and
band broadening. Classical chromatography theory considers that
the separation process takes place by a succession of equilibrium
steps, the more steps in a column the greater the column efficiency
with less band broadening occurring.
1
Peak broadening and splitting are undesirable and can lead to
inaccurate quantitation or misidentification.
Cause: Peak broadening of early eluting compounds is
commonly the first indication that the packing in the
cold trap needs changing.
Action: Replace or repack the cold trap. See Cold Trap
Maintenance on page 277.
Cause: Activity in the transfer line can also cause peak
broadening
Action: If this occurs, the section of capillary column or
the deactivated fused silica in the transfer line
CAUTION
You must ensure that tubes and caps are removed from the
current tube position before resetting the ATD or TD. Failure
to do so may result in damage to the instrument. Use caution
when removing tubes and caps.
1. A. Braithwaite and F.J. Smith, Chromatographic Methods, Fifth
Edition, (Glasgow, 1996), p27