Common Gas Chromatography Troubleshooting Tips

Gas Chromatography (GC) is a powerful technique, but it's not without its challenges. When problems arise, a systematic approach to troubleshooting is key. This article covers some of the most frequent issues encountered by chromatographers.

1. Peak Tailing

Peak tailing is often caused by active sites in the system. This could be due to a contaminated liner, a degraded column, or incompatible sample solvent. Start by replacing the inlet liner and septum. If the problem persists, trimming the front end of the column or conditioning it at a high temperature may help. As a last resort, the column may need to be replaced.

2. Ghost Peaks

Ghost peaks are unexpected peaks that appear in your chromatogram. They are usually caused by contamination from a previous injection (carryover) or from the system itself. Running a blank solvent injection can help diagnose the issue. To resolve it, bake out the inlet and detector, and check your carrier gas for purity.

3. Unstable Baseline

An unstable baseline can be caused by a column bleed, a contaminated detector, or a leak in the system. Check for leaks using an electronic leak detector. If no leaks are found, try conditioning the column. If the detector is the source, it may require cleaning as per the manufacturer's instructions.