Accounting for system and solvent peaks when reporting impurites?

edited January 2019 in Informatics
I have a related substances method which uses Area/CCalRef1[Area]*100 to calculate % Impurity for known and unknown impurities. However each sample has a certain number of "peaks" that are due to solvent or a system peak. I want to exclude these values when summing the total impurities and I cant find an efficient way to do this. If I name the peaks as Diluent, System etc then these peaks may not elute at the same time due to retention time shifts later on in the sample set (I run 5 batches per sample set). 

I tried to use the "Component Type" of Diluent or System Peak but again, this still requires you to name the peak, leading me to the same problem of retention time shifts. Does anyone have any suggestions on the best way to exclude these peaks without making it too complicated?


  • Use the peak label in the component editor of the processing method. Name the peaks what were you with, make the peak label "Blank" (as an example).

    From your custom field standpoint:

    ... + EQ(Peak Label,"Blank")*-1*50,000 ...

    What ever field is doing the above, sum it and use that summation to report your total.

  • Thanks Shaunwat that would do the trick I hope. 
  • or reversely... use some peak label (many users historically used a CConst field =1) to label the peaks you ARE interested in. Then have your summary calculation only use THOSE peaks. (That is what the Impurity Processing functionality does now automatically) Before we had all the new options the admin would set up Area x CConst1 as the response field.
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