Chromatographic Troubleshooting

Peak symptoms

Deformed peaks

The ideal peak, rarely occurring in chromatography, is a pure Gaussian shape. In practice, some asymmetry is always present, particularly near the baseline.

1. The peak rises normally, then drops sharply to baseline:

Figure 9-1.

Overloaded Peak

CThe most likely cause is column overload; dilute the sample ten•foldand run it again.

CThis may also be two (or more) closely merged (unresolved) peaks; lower oven temperature 30^C and repeat the analysis. If partial separation is seen, merged peaks are present.

2.The peak rises sharply and then falls normally to baseline:

Figure 9-2.

Abnormal Interaction with Column Material

211