PDA/FLR fields? Is it possible to reference extracted spectra values with a custom field?


There are a bunch of these PDA-type fields available when creating a new custom field. They vary from Match1 to Match3. 

PDA/FLR Match1 Angle
PDA/FLR Match1 Error

Anyone have info on what these represent or what uses they have?

Reason why I'm asking: Extraction Plots. I'm looking for a way to access the Extraction Table values (Wavelength, Absorbance) with custom fields. Right now I just use a report method and specify a extraction time, which works for identification, however I 'd like to eventually move toward a custom field that compares λ-max from two extracted spectra at an average RT and evaluate there.


Best Answer

    Accepted Answer
    In short, I don't think it is possible to do what you are asking in an automated way.  

    The fields you mention are related to peak purity/peak matching so I don't think those would help at all.  As an FYI, I've attached the help file associated with peak and result fields.

    I have an ID test using the "Peak Lambda Max" field: ..(Peak Lambda Max.)-SS01.5.(Peak Lambda Max.) where I can compare the wavelength maxima in a sample to that of a standard.  This field relies on the peak identification though, not a specific RT, so that a peak component of "API" is compared between the two injections with whatever spectrum/wavelength maxima is identified during integration.

    Calculating an average RT is easy enough and using the Peak Lambda Max field on the back-end is easy enough to compare with whatever mathematical comparison you want.  What needs to happen in the middle is for Empower to extract a spectrum at that average RT which I think is where your problem comes in.  I don't think there's any way to set up a custom field to extract a spectrum.

    If you want Empower to report it at all, you'd probably have to manually process the injections to extract a spectrum at your average RT.  Empower could then take the manual processing and re-summarize for any potential custom fields/intersample calcs to generate the desired values (e.g. a custom calc. using the Peak Lambda Max field).  Having to manually extract those spectra is not what you seem to be looking for though.


  • Dear MJS,

    Thank you for your detailed response. We'll keep doing it manually for now. It was worth a shot!
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