Reference chromatograms

With reference chromatograms, you can do a quick visual comparison of a sample chromatogram against another, specified chromatogram.

Reference chromatograms are stored in the processing method. You can therefore use the same reference chromatograms for all injections that you link to this method.

What do you want to do?

• Add a reference chromatogram

• Remove a reference chromatogram

• Display the reference chromatogram

Add a reference chromatogram

Prerequisites

• To be able to carry out the procedure as described, you need the privilege Processing Method > Edit signal parameters. Privileges are configured in the Control Panel.

• If the project enforces method approval, the method status must be Generic. For details, see Method approval.

1. Load the results that you want to use as a reference.

2. Open the method to which you want to add the reference chromatograms.

3. In the Processing Method window, select the General > Signals node.

4. Select the Reference Chromatogram tab.

5. If you have changed your data in the meantime, save all results.

Only saved data can be added as a reference chromatogram.

6. Click .

You can add up to five reference chromatograms.

7. In the Select reference chromatogram dialog, select the injection that you want to use as a reference. Click in the Signal field to choose the correct signal from the relevant injection.

By default, the dialog shows the focused injection plus all pinned injections.

The Signal drop-down list shows all signals for the selected injection that are supported for reference chromatograms and that are currently displayed in the Chromatograms window.

MSD signals, 2D-LC signals, chromatograms created by data extraction, and instrument curves are not available as reference chromatograms.



Each reference chromatogram is identified by the injection and signal that you choose in the Select reference chromatogram dialog. If a reference chromatogram already exists for a specific injection and signal, the existing reference chromatogram will be updated.

8. To select a signal from another loaded injection, clear the check box at the top of the dialog.

The dialog then offers all loaded injections with all of their signals.

MSD signals, 2D-LC signals, chromatograms created by data extraction, and instrument curves are not available as reference chromatograms.



9. Click OK.

10. Save the method, and link it to the relevant injections.

If the audit trail is activated for your method, an entry about adding the reference chromatogram will be added to the method audit trail. The audit trail entry includes the version number of the result set that you used as a reference. For more information about versioning, see Versioning.

Remove a reference chromatogram

Prerequisites

• To be able to carry out the procedure as described, you need the privilege Processing Method > Edit signal parameters. Privileges are configured in the Control Panel.

• If the project enforces method approval, the method status must be Generic. For details, see Method approval.

1. In the Processing Method window, select the General > Signals node.

2. Select the Reference Chromatogram tab.

3. Select the reference or references that you want to remove, and click .

Display the reference chromatogram

Prerequisites

• A processing method is linked to the displayed injection.

• At least one reference chromatogram is available in this processing method.

In the Chromatograms window, click to show or hide the reference chromatograms that are available in the linked method. The icon is only visible if a reference chromatogram is available.

A REF tag is added to the title of the reference chromatogram.

In Separate mode, reference chromatograms are always shown at the top. They are shown independently of the signals selected in the navigation pane.

Peak and compound annotations are identical to the other chromatograms. However, you cannot select the signal of the reference chromatogram.