Preventing air bubbles in the HPLC system

Air bubbles near the detector in the HPLC system can cause spikes in the chromatogram, affecting both the peak and baseline. This can lead to inaccurate analysis results as peaks cannot be integrated properly.

The most common cause of air bubbles is insufficient degassing of the eluents. It is important to note that column damage caused by air is minimal as the eluents are pumped through the column at high pressure. Several methods exist for degassing, with vacuum degassing being the most effective compared to helium purging and other methods. Another technique to prevent air bubbles is to apply low back pressure to the detector outlet using restriction capillaries and increasing pressure at the column outlet.