This Information Applies To: Agilent GC Systems
Several problems can be identified in GC chromatograms, and each of these problems can have various different sources.
Regular maintenance of your instrument in accordance with the recommended maintenance schedule will reduce the incidence of chromatography problems.
Steps to follow
The most common gas chromatography problems identified in a chromatogram include:
Ghost peaks or carryover (Figure 1).
See Source of Ghost and Carryover Peaks in GC
Figure 1. Ghost and carryover peaks
1. Clean blank run (no injection), 2. Contaminated run with ghost peaks and carryover
- Excessive baseline noise (Figure 2).
See Excessive Background Noise in GC
Figure 2. Excessive baseline noise
1. Normal background with peaks visible, 2. Excessive background with peaks partially obscured
- Baseline instability or disturbances (Figure 3).
See Baseline Instability in GC
Figure 3. Baseline instability
1. Stable baseline, 2. Unstable baseline
Fronting peaks (Figure 4).
See Peak Fronting in GC
Figure 4. Fronting peaks
1. Normal symmetrical peak, 2. Fronting asymmetrical peak, 3. Overload
Tailing peaks (Figure 5)
See Peak Tailing in GC Systems
Split peaks (Figure 6).
Retention time shift (Figure 7).
See Peak Retention Time Shift in GC
Figure 7. Retention time shift
1. Normal retention time, 2. Retention time increased
Change in peak size (Figure 8).
See Peak Size Changes in GC
Figure 8. Change in peak size
1. Some peaks change size, 2. All peaks change size
Loss of resolution (Figure 9).
See Loss of Peak Resolution in GC
Figure 9. Loss of separation
1. Normal retention time separation, 2. Separation, 3. Peak width
4. Decrease in separation, 5. Increase in peak width
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