Grouping Peaks

If you are interested in the sum parameters for two or more peaks, you can

1. Define these peaks as a peak group (that is treated as one single peak).

2. Define them as a group of peaks.

1. If the peaks lie close together and are not baseline separated, for example, with overloaded columns, define the peak group start and the peak group end via the Peak Group Start/End parameters on the Detection tab page. The baseline will then be drawn from the start of the peak group to its end. Such a peak group is treated as one single peak.

2. To define a peak group in which the peaks do not necessarily succeed one another, for example, to determine the amount/concentration of an entire class of substances, take the following steps:

• Identified peaks: Select Column > Display Column on the context menu to insert the Group column into the peak table if the column is not yet displayed. For those peaks that should belong to this group, type a group name into this column.

• Unidentified peaks: Click Unidentified peaks… on the General tab page to define the period for which this group shall be valid. The baseline will be drawn in the same way as for individual peaks.

• Add the Group Amount column to the Report and the Printer Layout. This column shows the desired Amount value. In the report, open the dialog box Insert/Add Report Column via the Insert Column or Add Column commands on the context menu. Select the Peak Results category and then choose Group Amount as variable.

 Tip:

If the selected calibration type is, for example, LOff instead of Lin, the value in the Group Amount column will not be identical to the sum of the amount values of the individual peaks even if the group includes all peaks of the chromatogram.