This Information Applies To: Agilent GC systems
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.
Tailing can be caused by several reasons. Figure 1 shows some examples of peak tailing at several degrees.
Tip: Some active compounds always tail.
|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
|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.
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