Separate peaks and estimate peak volumes using the Peak Separator

Analysis has a functionality that allows the user to separate overlapping peaks automatically, the Peak Separator popup, which is accessible through M: Peak: Peak Separator:

The Peak Separator uses a Markov Chain Monte Carlo search which uses idealised peak model shapes in attempts to deconvolve overlapped peak regions into their separate constituent peaks. The Peak Separator is not intended to be used for peak picking. The functionality should rather be used for separation of peaks in regions of overlap, and to estimate peak volumes. The Peak Separator may be suitable for fitting model shapes to single peaks, in order to calculate precise intensities. To pick peaks in an overlapped region, do as follows:

• • Set the minimum number of peaks to be found in “Min. number of peaks:”. This parameter is by default set to one, it is not possible to set this to a value less than one.

  • Set the maximum number of peaks to be found in “Max. number of peaks:”. This parameter is by default set to one, increasing this value allows the search routine to fit more models. Higher numbers slow the routine, and setting this value to 0 allows the routine to (effectively) fit unlimited peaks.

  • Set wherever you want to search for both negative and positive peaks in “Only pick positive peaks:” If you are not interested in negative peaks, removing the possibility of fitting negative peaks can reduce search time.

  • Set “Peak Model:” to search the spectra for peaks with either a Gaussian peak model or a Lorentzian peak model.

  • Set the “Peak List:”, to which the newly picked peaks will be added to. Peaks picked using the Peak Separator will have their |Details| column in M: Peak: Peak Lists, {Peak Table} appended with “PeakSeparator” so you know where they came from.

  • Go to the {Advanced Settings} tab and set advanced settings, usually this is not necessary.

  • Select the region to apply the Peak Separator to by drawing a box over the region (mouse left).

  • Click [Add Region] to add the region to the Peak Separator’s ‘Region’ table.

  • Click [Separate Peaks] to separate and pick peaks in the region. Have a look in the python prompt to see the calculations. This may take a few minutes to run, depending on the size of the spectral region being searched, the number of peaks being fitted and the speed of your machine.

After a successful run, the identified peaks have been added to the selected peak list. The peak intensities (and volumes) have been calculated using the selected peak model.