Deconvolution of Natural Isotope Distributions

In addition to the incorporated deuterons, a deuterated peptide also contains other natural occurring heavy isotopes such as C, N, 0, S, etc. To see the true distribution of incorporated deuterons, it is sometimes desirable to remove the contribution of natural isotopes from the observed isotope distribution in a spectrum. 

In most modem HX-MS experiments, the mass spectra are collected in high resolution, when all isotopic peaks, but usually not the isotope fine stractures, are resolved. The observed spectrum / (fw) (observed intensity of the isotopic peak with mass of m) of a deuterated peptide is a convolution of natural isotope distribution and the distribution of incorporated deuterium A as shown in Equation 7.13  

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