Efficient Calculation of Exact Mass Isotopic Distributions

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 × 10 11. 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.