Jo Boden
Carlos VargasThis Information Applies To: Agilent GC systems
Issue
Peak fronting is present in a chromatography peak when it has an excessive asymmetry with a trailing edge. A normal peak is almost symmetrical.
Other chromatographic problems are identified in Basic Troubleshooting for GC Systems . Regular maintenance of your instrument in accordance with the recommended maintenance schedule will reduce the incidence of chromatography problems.
Background
Tailing can be caused by several reasons. Figure 1 shows some examples of peak tailing at several degrees.
Figure 1. Peak tailing
1. Symmetrical peak with no tailing
Resolution
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Tip: Some active compounds always tail.
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| Possible cause of tailing | Solution | ||
| Split ratio too low | Increase the split ratio | ||
| Column contamination | Bake out the column. Limit the bake-out for 1 to 2 hours or until the signal is stable
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| Column activity | Irreversible. Replace the column | ||
| Improper injection technique (slow/erratic plunger depression) | Check that the syringe plunger is moving freely. The solution should be pulled into the syringe body, and moving freely and fast when plunger is depressed | ||
| Improper column installation, including poor column cutting | Remove and reinstall the column. See Capillary column installation quick reference guide | ||
| Solvent effect violation for splitless or on-column injections | Lower the oven start temperature | ||
| Mixed sample solvent with large differences in polarity or boiling points | Change the sample solvent or use a retention gap |
If these procedures have not resolved the peak tailing problem, contact Agilent Technical Support.
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Learn how to effectively troubleshoot your Agilent GC System:
GC-0GEN-1040z - Practical Steps in GC Troubleshooting
GC-0GEN-2040zs - GC Troubleshooting Series e-learning courses available from Agilent education |
