As is well known, in non-suppressed ion chromatography a system peak appears after every sample injection. The same is true for suppressed ion chromatography. Here the system peak is usually much smaller but nevertheless may interfere severely with ions of interest. In some cases the operator is not even aware that a peak of interest is hidden by the system peak.
The origin of the system peak as well as the factors influencing its size and position are still under discussion. The two main effects are:
- the system peak elutes at the elution time of the eluent anion
- the size of the system peak depends on the sample matrix
Knowing the position of the system peak with different types of columns allows you to select the columns according to the needs of your application.