Named group/ Time group result in Sequence Report

Hi All,

I am aware that this problem has been answered well in this forum but I am not able to solve it for my scenario. 

In my analysis, i have two peaks which are the meta- and para-cresol. I want to show the peak area and percentage area of sum of both peaks.

In processing, I grouped both peaks using timed and named. Only timed appeared as below using the group Table template. Not sure why the named did not even show in the processing Tab.

My question is why the peak area % is not the combined value. How to correct it? 

Another question is how to not split the merged peak during automatic integration in Openlab CDS 2.3?

I tried by changing the peak width and skin to valley ratio but it is not a good way as it affects the integration of small peaks for other samples. 

Thank you for your help :) 



 References referred. 

 How can I add timed group (isomers) in the OpenLAB Intelligent Report?  

 Display grouped peak summary in sequence summary reports 

  • Hello,

    The system will not sum the area percent for the timed groups as there is no group area sum like there is compound area sum. My guess on why the name group is not displaying would be a problem with the filters on the table you are displaying. For timed groups you could recalculate the area percent using the compound_area using the CC below. This would also work for named peaks but only for one signal channel.

    CurrentPeakOrGroup.Compound_Area / CurrentSignal.AllPeaks.Select(function(x) x.Peak_Area).Sum * 100

    As for the integration you could time program the peak width and VtoV ratio so the settings only effect that time range, or you can try the timed event area sum around those peaks.

    Marty Adams

  • Hi Martin, 

    Thank you for your reply. It is useful. I have tried on the Openlab CDS 2.3 and the CC works.

    For some injections, the sum is incorrect (the sum is above 250%). The injection is performed using MS in SCAN mode and during the data processing, there are few Extracted Ion Chromatograms generated because I have many peaks at different m/z. 

    I feel the CC sum the peak area from all different Extracted Ion Chromatograms before dividing to the sum of all peaks of one signal. 

    How can I specify the CC to only take peak area from TIC SCAN chromatogram  before dividing to the sum of all peaks found in TIC SCAN chromatogram?

    Thank you :)




  • Kris,

    Since the named group has no association with a signal the software picks up the first signal for that sum. If you want to force a specific signal to be used the CC below would work where you replace the exact signal name for "DAD1A". 

    Marty Adams

    CurrentPeakOrGroup.Compound_Area / CurrentInjection.SignalByName("DAD1A").AllPeaks.Select(function(x) x.Peak_Area).Sum * 1

  • Hi Martin, thank you again, Now the CC works well. :) 

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