Open Lab CDS 2.2 Question for Calibration

Question

Hello Everyone,

I'm new to Open Lab CDS and I currently have version 2.2 paired with a Agilent GC-FID. I'm still learnng the software and I had a few questions in regards to calibrating and calculating uncalibrated peaks. In Open Lab CDS, how do I calculate uncalibrated peaks using a known compound? I'm used to seeing this in Open Lab Chemstation in "Calibration Settings" but can't find that open in Open Lab CDS. Also, how do I recalibrate a processing method? I'm used to just running standards and going into "Calibration" and recalibrating my different levels manually under "Recalibration". In addition, is there a function to replace the existing calibration for a level and then average the response factor for different runs for the same level? I run all my standards in triplicate so it's something I'm trying to figure out.

Thanks for any help that you can provide.

Ryan

camelia · Accepted Answer

Hi Ryan i also run a method where target compounds are quantified using the response of a reference compound that crucially is not present in the sample chromatogram. Unfortunately OL 2.2 is not able to automatically quantify the target compounds using the Reference selected in the calibration table unless that reference compound is present in the sample This is confirmed in the Help and Learning. To quantify the target compounds you will need to either spike the samples with the reference standard, or use the calibration equation generated from the reference standard together with a custom calculation to calculate the concentration of the target compounds or get OL 2.3. In OL 2.3 it is possible to use the Reference mode of calibration to quantify target compounds in chromatograms that do not contain the reference compound. Sorry to be the bearer of bad news.

ryoboyle · Answer

Hello Ryan, I added tags to this post to increase visibility. To perform quantitation on uncalibrated peaks in OpenLab CDS you would still need to add the peaks to your Processing Method's compound table. Once added, you can select a quantitation mode of either Manual factor or Reference as opposed to the default value of curve (which would require you to run calibration standards and build a calibration curve for the compound): The Manual factor mode allows you to define a fixed response factor to be used when calculating amounts and concentrations for that peak. The Reference mode, you can specify a reference compound (which would already be calibrated) and that reference compound's calibration data will be used when generating results for the uncalibrated peak. As for your second question: yes, it is possible to replace the existing calibration during reprocessing and then average subsequent cal points of the same level. This is controlled by the 'Run type' column in your Sequence Table (for Acquisition) or Injection List (for Data Analysis). If you wish to clear the calibration data for ALL levels, you would just specify a run type of 'Clear all calibration' for your first calibration standard in your sequence. You can also choose 'Clear calibration at level' if you wish to only clear the calibration data for one particular level. If you leave the Run Type column empty for a calibration sample, then previous calibration points will stay in the calibration curve after reprocessing. Hopefully this helps.

Open Lab CDS 2.2 Question for Calibration

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