Peak Shape Problems: Broad Solvent Peaks/Fronts

In this technical tip, we will address a common issue encountered in Gas Chromatography (GC) analysis: Broad solvent peaks/fronts. These distorted solvent’s peak shapes can adversely affect the accuracy and reliability of your results making determination of early eluting compounds very difficult. Let's explore possible causes and suggest remedies:

Symptom: Broad solvent peaks / fronts

Phenomenex: Peak Shape Problems: Broad Solvent Peaks/Fronts

Possible Cause  /  Suggested Remedy

• Bad column installation: Reinstall column.
• Injector leak: Find and fix leak.
• Injection volume too large: Decrease sample size.
• Injection temperature too low: Increase injection temperature so the entire sample is vaporized “instantly”. An injection temperature higher than the temperature limit of the column will not damage the column.
• Split ratio is too low: Increase split ratio.
• Column temperature too low: Increase column temperature. Use a lower boiling solvent.
• Initial column temperature too high for splitless injection: Decrease the initial column temperature. Use a less volatile solvent so the initial column temperature is at least 10°C below the boiling point of the solvent.
• Purge time too long (splitless injection): Use a shorter purge activation time.
• Septum purge plugged or turned off: Remove plug or turn septum purge on.

By addressing these potential causes and implementing the suggested remedies, you can easily overcome the issue of broad solvent peaks/fronts, improving the peak shape and the overall accuracy of your GC analysis.