Journal of the American Society for Mass Spectrometry

, Volume 18, Issue 8, pp 1511-1515

First online:

Efficient calculation of exact mass isotopic distributions

  • Ross K. SniderAffiliated withTechnology, Inc.Department of Electrical and Computer Engineering, Montana State University Email author 


This paper presents a new method for efficiently calculating the exact masses in an isotopic distribution using a dynamic programming approach. The resulting program, isoDalton, can generate extremely high isotopic resolutions as demonstrated by a FWHM resolution of 2 × 1011. This resolution allows very fine mass structures in isotopic distributions to be seen, even for large molecules. Since the number of exact masses grows exponentially with molecular size, only the most probable exact masses are kept, the number of which is user specified.