7
Diagnostics and Troubleshooting
Troubleshooting
142
TSQ Quantum XLS and TSQ Quantum GC User Guide
Thermo Scientific
• Method development problems are present. Contact Thermo Fisher Scientific Technical
Support.
Issue:
Sensitivity is
unstable or shows
decrease with repeated
injections.
Possible causes/solutions
• The GC temperature ramp does not continue to a high enough temperature to elute high
boiling point compounds. Multiple injections cause these compounds to accumulate in a
column, reducing sensitivity. Extend the upper temperature or the time at upper
temperature in the GC oven ramp.
• The ion volume or lenses are contaminated. Clean the ion volume and lenses as described
in
“Cleaning Ion Source Components”
• The ion source temperature is too low and causes the ion source to contaminate too
quickly. Clean ion volume and lenses as described in
“Cleaning Ion Source Components”
and then raise ion source temperature.
• There is a problem with the filament emission current control. See
for more information.
• The electron multiplier is faulty. Contact Thermo Fisher Scientific Technical Support.
• The injection port liner or capillary column is contaminated. Replace the injection port
liner and trim the capillary column.
Issue:
Poor
sensitivity in
CI mode.
Possible causes/solutions
• An EI ion volume is installed. Install a CI ion volume as described in
.
• The small hole in the CI ion volume is plugged. Use a dental pick or old syringe needle to
clear it.
• The filament is not aligned. Remove the ion volume and check if the ion burn is centered
around the small electron entrance hole. Be sure the filament is properly inserted into the
connector. Carefully bend the filament wire to better align it with the ion volume.
• The ion volume is not inserted properly. While running the instrument, you can push on
the ion volume with the I/R tool. Be sure to monitor the pressure to ensure that you get a
good seal around the I/R tool. Otherwise, you may damage the filament. An increase in
signal calibration gas as you push on the ion volume usually indicates that the filament is
not aligned properly.
Stability Issues
Stability helps provide consistent instrument precision and the reproducibility of accurate
results. Good operating conditions for the mass spectrometer, gas chromatograph, and
autosampler contribute to instrument stability.