Can you only have a Curve Reference if you process samples sets including 'Amount'?

I have a related impurities test which tests % impurity by the following formula:
Area of impurity*RRF*100/Area of Active. I have a custom field for this which works well ie Area*RRF*100/CCalRef1[Area] but how do I take into account the RRF and does Empower automatically assign an unknown peak with an RRF of 1? I know you can select a curve reference and that gives you a space to enter RRF but for my custom field to work on all knowns and unknowns would I have to NAME all peaks in my sample then calibrate and quantitate to process the sample set?

If I use the default peak option, wont this only calculate unknowns is some kind of calibration and quantitation occurs? Currently results are written up on Excel..

Best Answer

  • Accepted Answer
    The impurities tab is designed to eliminate this particular gap when processing impurities: when you need a default value for an unnamed peak (not in your component table).  I believe you can set up a general/default RRF but I'm no expert

    You might think of creating your own custom field for RRF rather than using the built in one. You could then set a default value for that field which will only be modified if the CConst value is entered. RRF=CConst5; Default value 1.2

    There may be a way to use the Default peak for all unknowns in a region. The unknown peaks may pick up the RRF value but again, its been a long time.

    I think there are may ways to skin this particular cat


  • If you aren't naming all peaks, maybe a simpler approach (to ignore all the peak naming/calibration curve issues) would be to implement a bit of boolean logic into the mix.  Maybe a peak type test where if it is a named component ("Found" peak type), then you'd calculate exactly like you always have, and if not, you specify a value of 1 instead of the RRF field.  I think you'd essentially need 3 total fields to pull it off.  The first is your existing field (I'll call that ImpFound) and the second is the altered field with the 1 substituted for the RRF (I'll call this one ImpUnk).  The third would be the boolean test.

    The following is rough and untested, but something like: EQ(Peak Type, "Found").  If it is a found peak, it will return a 1 which would be translated to "ImpFound (fc)" in your translation definition.  If not a named component, it would return a 0, which you would translate to "ImpUnk (fc)" in the translation definition.  You'd then report the result of the boolean field (not the called sub-field) for any final result.

    Just as another catch...ensure you've properly configured the fields for Founds and Unknowns.
  • Thanks, another way to set it up within the one custom field would be EQ(Peak Type,"Found")*(Area*RRF*100/CCalRef1[Area])+EQ(Peak Type,"Missing")*(Area*1*100/CCalRef1[Area]).
  • Just to follow up, doesn't Empower 3 have an Impurity RRF tab set up automatically in the Components tab so there is no need to set curves against components?
  • So, yes, you could use that, but then the peak would have to be named in order to show up in the table where you could then enter a value of 1 which is something you specifically wanted to avoid having to do for all peaks present in each sample injection.  Using the custom field option discussed eliminates the need to name all the peaks to achieve the same result.  So, it comes down to which you'd prefer I suppose, name all peaks and use built-in fields possibly or use a custom field and not have to name everything.
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