Defining Detection Parameters
Defining Rider Peaks

The detection parameters Rider Threshold and Maximum Rider Ratio allow you to define which peaks shall be detected as Rider Peaks and which shall be detected as main peaks. The following applies:

The smaller the rider threshold is, the smaller are the peaks that can be detected as rider peaks. (Peaks below the rider threshold are always regarded as main peaks. For peaks above the rider threshold, the Maximum Rider Ratio defines whether a peak is a rider peak or a main peak.) The larger the maximum rider ratio is, the larger the peaks that can be defined as rider peaks.

 Tip:

When defining rider peaks with these parameters please keep in mind that the same peak may be detected in two different chromatograms as main peak and as rider peak. This would result in considerable deviations; for example, in the calibration. To prevent this, select the peak type Rider (or Main) for the respective peak in the peak table. Thus, the peak is a rider peak, if possible (or always a main peak).

In addition, you can define how to skim rider peaks by using the Rider Skimming parameter. With the two options Tangential at lower peak end and Tangential at both peak ends the peak is skimmed by a tangent. Usually, there is hardly any difference between the results of the two options.

With the Exponential option, the course of the baseline is approximated by an exponential function; that is, the peak is skimmed by the exponential function. This option clearly distinguishes from the two others. In most of the cases, Exponential maps the actual baseline course very accurate. With this option, the rider peak will usually receive a more realistic larger area. To be able to use this option, make sure that a sufficient number of data points is available.

 Tips:

You can move the baseline in the chromatogram with the mouse for tangentially skimmed riders, but you cannot for exponentially skimmed riders.

Split Peak on the context menu allows splitting one rider peak into two peaks.