Baseline calculation

The first step when you integrate peaks is to calculate a baseline. A correct baseline is crucial for accurate calculation of the peak areas. This section describes the options for how to calculate baselines in the Integrate dialog box.

UNICORN™ offers several options for how to create an accurate baseline:

• To use the automatic Calculate baseline function.

• To create a baseline based on a blank curve.

• To use a Zero baseline.

• To reuse an existing baseline.

The Calculate baseline instruction provides automatic calculation of the baseline. In most cases the measurement is very accurate. The calculation can be performed using the Morphological algorithm or the Classical algorithm.

A blank curve can be used as the baseline for peak integration.

• You can use a blank curve with the same chromatographic conditions as the corresponding sample.

or

• You can subtract the blank run from the source curve and then perform peak integration on the resulting curve with the Calculate baseline instruction.

Note: In addition to blank run curves, it is also possible to select any curve from the current chromatogram as the baseline, e.g. an edited baseline.

To use a Zero baseline means that there is no baseline subtraction at all.

To reuse an existing baseline for the selected curve is the default alternative whenever there is an existing baseline available. The option Correlated baseline is selected if this is the case.