pda functions

[sindibad]

n the PDA method setup, I have to set a purity threshold (values comprise 0 to 1000).
I know if it is 1000 than the peak is most probably pur

the set value of absorbance threshold, is it linked to LOQ or LOD?, means the values of signal to noise?, in which case should I put 2 or 5 or 10%
- background correction is only for gradient of mobile phase and if I leave it not cheked?
Many thanks

[Ivan Vins]

Peak Purity value is calculated as a match between the peak apex spectrum and all the spectra thorough the peak boundaries. Perfect match is represented by 1000. The values are plotted in the Peak profile window, the average is reported in the Result table. For pure peaks, the profile should be more or less rectangular.

In the PDA method, Peak Purity section, the Peak Purity Threshold (0-1000) and Absorbance Threshold (0-100%) are used to eliminate spectra not exceeding the set values, as they probably represent just noise and will affect the average value.

[sindibad]

ok thanks

[Ivan Vins]

Chromatogram, Add signal in PDA window allows you to create a new signal in chromatogram for selected wavelength. Such signal could then be integrated in the Chromatogram window.

Spectrum, Add to Library in PDA window serves to add the selected spectrum to actually opened Spectral Library

Please refer to the help or manual

http://downloads.dataapex.com/documenta ... ns-pda.pdf