What is Peak Purity or Deconvolution?
Peak purity analysis’s purpose is to detect the presence of an impurity that is coeluting with the desired analyte peak. For impurity detection with a single wavelength UV/visible detector, we found a shoulder, valley, or excessive tailing to suspect the existence of an impurity.
PDA detector (A photodiode array detector).
Peak Purity is an analysis of spectral changes or deviation, assuming the impurities are spectrally different from the analyte or desired substance.
When no significant spectral changes or deviation are found within a peak, one can assume that the peak is spectrally similar and probably contains only one compound.
The software examines spectral noise and the random events which cause small deviations in spectra, from a user-selected segment of baseline. This is called the “Threshold”.
When the purity plot is above this noise threshold, the spectral fluctuations are recognized to be greater than random noise. This provides a level of assurance in that a spectral impurity has been found.
When an impurity is detected, the purity plot increases above the threshold line. This displays spectral changes outside noise contributions and indicates the presence of more than one compound in the chromatographic peak.
An angle of 0° indicates the spectral shape is identical and an angle of 90 degrees indicates no spectral overlap.
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