OpenLAB Custom Calculator

Hello ryoboyle,

Thank you for the reply and for realising that I had posted  a duplicate by mistake - apologies.

To answer your questions:

• We are running OpenLAB CDS 2.3
• There is only going to be one Method Blank per sequence
• Yes, you are correct, I only want take the area for one specific compound/timed group and subtract that from all the sample injections only.

I hope this helps, thanks

Hello,

I added tags to this post to increase visibility. 

What revision of OpenLab CDS are you using? 

Is there just going to be one blank run in your sequences or are there going to be multiple blank runs per sequence. If there are going to be multiple blank runs, then do you want to average the areas of your peak of interest across the injections and then subtract that value from the rest of the runs?

And to clarify, you only want to take the area of one compound from the blank run to then subtract from other runs, correct? Or do you want to do this for all compounds? 

Hi,

Thanks for these possible options.

I will give them a go and hopefully they will work.

I will definitely come back to you with some feedback after I have tried them early next week.

Take care,

Regards,

Naweed

See below screenshots and give it a try to see if it works for your purposes. You will need to replace "Compound_A" in the CompoundA_BlankArea formula with the name of your compound.

CorrectedArea should report Compound_Area for all compounds except for the identified compound in the CompoundA_BlankArea formula where it will report Compound_Area with the area from that compound in the blank injection subtracted. 

Hi Ryoboyle,

                Thank you for these tips – this worked wonderfully.

                I even managed to change the blank for a system suitability blank – such that I could subtract the method blank from the sample areas and the system suitability blank from the standard areas.

                The only thing I struggled with was the second calculation, which wouldn’t work initially as written.

                I then tried : Compound_Area-CC14, CC14 was the custom calculation for the blank area.  This worked fine.

                Now, my next problem is that I couldn’t find a way to get the subtracted result calculation into the report editor, when I tried to use the field ‘Custom Calculation Results’ in the Fields and then Compounds option – it imports the description correctly but not the actual result – it gives me a zero result for the blank area and it picks the area of peak one from the result table and displays this in the corrected area field.

                Any help here would be highly appreciated.

                Apologies for the late reply, I have been out of the office for a few days and could not try these calculations.

Are the correct values being displayed properly in the Injection Results window in Data Analysis? If so, then there shouldn't be a problem with those values then being pulled onto a report. Are you trying to add the correct area as a new column in a results table on the report template? Can you send me screenshots of what is happening on the report?