7
Diagnostics and Troubleshooting
Troubleshooting
Thermo Scientific
TSQ Quantum XLS Series User Guide
117
Issue:
Unable to
initialize the
autosampler.
Possible causes/solutions
• The autosampler is not turned on. Turn on autosampler.
• The autosampler is not configured properly in the Xcalibur data system. Check
Instrument Configuration.
• The cable between the GC and autosampler is disconnected. Verify connection.
• The autosampler instrument configuration is not set to the correct port. Verify
connection and configuration.
Issue:
Unable to
download methods to
the autosampler.
Possible cause/solution
• There is a discrepancy between instrument method and configuration. Verify consistency
between instrument method and instrument configuration.
Contamination Issues
Chemical noise is always present in any mass spectrometer. As a result, the high sensitivity of
the mass spectrometer can cause new users to confuse background with a contamination
problem. Additionally, the spectra shown in Xcalibur Tune and Real-Time Display are
auto-normalized, which can make the background level appear high.
Some chemical noise does occur, such as septum bleed after a series of injections, vial sample
bleed (which occurs if more than one injection is made from a sample vial), and siloxane peaks
that appear in the chromatogram at regular intervals from focusing at the head of the column
or in the injector.
Other possible contamination sources include hydrocarbon contamination of the carrier gas,
pump oil, or instrument cleaning solvents.
Always wear clean, lint- and powder- free gloves when handling ion source and mass analyzer
components, and ensure that the carrier gas filter, carrier gas lines, and gas regulators are free
of contamination and leaks.
Issue:
Excessive
chemical background
due to a column bleed
(
m/z
429, 355, 281).
Possible causes/solutions
• The capillary column has not been properly conditioned. Condition the capillary
column.
• The capillary column is damaged as a result of exposure to oxygen. Find the source of the
oxygen in the carrier gas or air leak. Recondition or replace the capillary column.