EP s/n of a peak versus a region in the blank

We would like to get the EP s/n of a peak in an injectio not versus a time region (start time to stop time) in the same injection but in a time region in the blank.
I mean getting the EP signal/noise of a peak in a injection related to a time region of the blank injection (injection of diluent, mobile phase...). So from different injections

Hope somebody knows it..

Answers

  • You would need to set up a few custom fields to match the EP s/n formula which is:

    2*((Height-0.5*(PeaktoPeakNoise)*Scaling)/(PeaktoPeakNoise*Scaling)

    Make sure you have "Calculate EP s/n" ticked in your processing method and for noise pick PeakToPeakNoise and a suitable Baseline Start and End value, which you would also input in the Noise and Drift Tab. In order to calculate the EP s/n of a peak in one injection but use it based on the noise range of another injection, set up 3 CFs and give the injection where the noise is required a label in the sample set example Diluent

    1. Peak, Real, CF Result Set Only

    Height-(0.5*(Diluent.%.(PeaktoPeakNoise))*Diluent.%.(Scaling)

    2. Result Real CF Result Set Only

    Diluent.%.(PeaktoPeakNoise)*Diluent.%.(Scaling)

    3. Peak Real CF Result Set Only

    2*((CF1/CF2))

    Process sample set to generate a result set and you will get a value for EP s/n for peaks based off of using the height of the peak and using the values for PeakToPeakNoise and Scaling in the injection marked Diluent. You may want to have a small precision for CF3 as the result may be quite large.