Hi, I have created a named group in the calibration compound table. The named group called Total consists of Compound A and Compound B and Compound B uses Compound A as a curve reference. Is it possible to generate a calibration curve of the named group Total? I am using OL 2.3. Thanks
Hello,
I added tags to this post to increase its visibility.
Named group amounts are concentrations are calculated by just summing the amounts or concentrations of all of the group's component members. For example, if you have a named group consisting of Compound A and Compound B then the group's concentration is going to be Compound A's concentration + Compound B's concentration.
This means that the group as a whole is not calibrated but rather the individual members of the group are calibrated.
Hopefully this helps.
Hi Rob, Thanks for your quick reply. Please could you confirm that it is not possible to generate a calibration curve from a named group. Best Regards
Hi camelia,
That is correct. Named Groups are not calibrated as a whole in OpenLab CDS, but rather the group members are calibrated and the group's results are calculated as the sum of its members' results.
Hi Rob, Thanks for clarifying this. Kind Regards
Hi Camelia,
although it is not possible to calibrate a named group as such, you could achieve the same by using a timed group.
Timed groups can be setup with various regions and if you choose the retention time windows of your expected peaks you can calibrate it as a group.
If you want to label the individual compounds with their names, you can set up in the identification table, but not define calibration levels for those compounds. (Otherwise they would be quantified twice).
If a 2nd peak slips into a defined time region, it also gets quantified - so the width of the region need to be selected carefully.
This workflow doesn't fully replace a quantification based on a named group, but still may simplify the method setup.
Hi betrich, thanks for the information. I will try this to see if it offers a workaround.
Hi Betrich
yes this helps and I can quantify the compound group as required. The problem is that although the calibration curve and r2 value is visible in the OpenLab Calibration curve window the default calibration report templates provided by Agilent do not pull this data in and I am unable to print the timed group calibration curve.
Updated - This issue has now been resolved using a workaround to output the r2 using the expression: =CalibCurve_CorrCoefficient*CalibCurve_CorrCoefficient. It is a known defect which has been fixed in version 2.5
Kind regards
Hi camelia,
That is correct. Named Groups are not calibrated as a whole in OpenLab CDS, but rather the group members are calibrated and the group's results are calculated as the sum of its members' results.