Jo Boden
Carlos VargasThis Information Applies To: Agilent GC Systems
Issue
Peak splitting is when a single compound is shown in the chromatogram as two peaks usually unresolved, or one of the peaks is a shoulder.
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
Peak splitting and broadening are a result of the analyte being deposited incorrectly onto the column (Figure 1):
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Tip: Peak splitting is a single compound effect, not near coeluting compounds.
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| Possible cause of peak splitting and broadening | Solution |
| Injection technique (manual injection) | 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. Use an autosampler |
| Improper column installation | Remove and reinstall the column. See Capillary column installation quick reference guide |
| Injector temperature too low | Increase the injector temperature to ensure fast transfer of analyte to the column |
| Injector temperature is too high, causing analyte degradation | Reduce the injector temperature or change to an on-column injection technique |
| Mixed sample solvent with large differences in polarity or boiling points | The analyte has different solubility in different solvents. Change to a single solvent |
| Poor sample focusing | Use a retention gap |
If these procedures have not resolved the peak splitting, 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 |
