INFICON
Troubleshooting | 11
074-594-P1H Micro GC Fusion Operating Manual
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11.2.1.3.4.4 Split Peak Apex
Ensure that this is not a merged peak by conducting a run at a lower column
temperature. If the peaks separate at the lower column temperature, the split peak is
due to unresolved compounds.
Hydrogen peaks, analyzed with a thermal conductivity detector and helium carrier gas,
often show a split peak apex. Reduce the Inject (ms) time until the split is resolved. If
using a variable volume or fixed volume injector, do not reduce the Inject (ms) time to
less than 15 ms to avoid repeatability issues.
11.2.2 Method Problems
This section describes how to troubleshoot a method and solve problems that arise
from incorrect Micro GC Fusion parameter settings, wrong peak identification
windows, and inappropriate peak detection parameters. These conditions cause an
erroneous calculation of the mole percent composition of samples. Troubleshoot the
method if the following symptoms are observed in the reports and chromatograms
when running a calibration standard.
• Zero mole percent composition for components known to be present
• Peaks are not being integrated, or are being integrated incorrectly
• Unusually high or low mole percent composition
• Samples with unnormalized totals outside the 95 to 105% range
11.2.2.1 Correcting Instrument Parameter Settings - Adjusting Column
Head Pressure
Column head pressure controls flow through the column, and directly affects the
retention time of all peaks in the run.
1 Determine the retention time for the start of the first peak for all modules in the
calibration standard.
