Use 2D time reference compounds

In addition to the 1D time reference compounds you can also use 2D time reference compounds. For 2D compounds with associated 2D time reference compound, the ¹D and ²D retention times are corrected independently based on the ¹D and ²D shifts observed for the associated 2D reference compound.

Setting up 1D time reference compounds is described in the core Data Analysis help.

For more information on time reference compounds and on the related calculations, see Time reference compounds.

Preparations

• To be able to carry out the procedure as described, you need the privilege Processing Method > Edit identification 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. Under Methods in the navigation pane, select the processing method you want to edit.

2. In the Processing Method window, select the Compounds > Identification node.

3. Select the General tab.

4. Select Use 2D time reference compounds.

5. Select the Compound Table tab.

   The columns Is time ref., Associated time ref., Factor ¹D and Factor ²D are now visible in the compound table.

6. For the 2D compounds that you want to use as time reference compounds, select the Is time ref. check box.

   If you use internal standards, the compounds used as an internal standard are marked as time reference compounds by default.

7. For the other 2D compounds, select the associated 2D time reference compound from the drop-down.

   You can only associate 2D time reference compounds with 2D compounds.

8. Check the values for Factor ¹D for the ¹D RT and Factor ²D for the ²D RT, and adjust them as required.

   The default factor is 1, that means the time shift is applied in the same way as for the time reference compound. A factor greater or smaller than 1 amplifies or diminishes the correction per compound.

9. Reprocess.

   The corrected expected ¹D and ²D retention times are used to identify the 2D peak.