Tune shoulder detection (Data Analysis)
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Tune shoulder detection

The integration optimizer helps you find peak shoulders. Adjust the parameters as follows:

In step 1: Characterize Chromatogram

To enable shoulder detection, select the Detect shoulders check box. It is available if:

  • You create a new set of integration parameters

    and

  • You use the ChemStation integrator

In step 2: Integration & Tuning

With Detect shoulders selected, the integration optimizer proposes the parameters as follows:

  • Peak width: If you have defined a time range for the smallest peak, not only the height but also the width of the smallest peak is taken into account for the proposed peak width.

  • Peak reject by: To optimize the number of detected shoulders, adjust the Area reject value. Area reject is used by the algorithm to eliminate insignificant shoulders based on a preliminary approximation. See Initial events.

  • Peak separation mode: Set to Drop.

    When you choose another peak separation mode, both Shoulders mode and Tangent skim mode are changed to their corresponding values (Drop and Straight, both Gaussian, both New Exponential, or Tangential and Straight).

  • Skim ratio: Initially set to 0, so that only shoulder detection is enabled. Rider peaks are therefore integrated as individual peaks separated by a drop line, independent of the peak separation mode.

    When you increase the skim ratio, both Tail peak skim height ratio and Front peak skim height ratio are automatically set to the corresponding value.

  • Two Detect shoulders events: Set to Off at 0.000 min, and to On about 2 min later, depending on the signal. Move the On event to the front of the peak whose shoulders are relevant. Add another Off event as required when shoulders are no longer relevant. To add or move events see Tune timed events in the chromatogram.

The Integration Optimizer will remember the peak separation mode and skim ratio parameters when you navigate between the steps, and also when you restart the wizard.

In step 3: Finalize Parameters

You can adjust each integration parameter individually in the integration events table (see Tune using the integration events table).

In the Advanced section, Baseline correction mode is set to Advanced+ for an optimized shoulder detection.

See Also