American Chemical Society
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Fast Graphically Inspired Algorithm for Assignment of Molecular Formulae in Ultrahigh Resolution Mass Spectrometry

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journal contribution
posted on 2015-05-19, 00:00 authored by Nelson W. Green, E. Michael Perdue
This study focuses on the deterministic task of assigning molecular formulae to exact masses that are generated by ultrahigh resolution mass spectrometry. A new algorithm based on low-mass moieties (LMMs) such as CH4O–1 and C4O–3 completely replaces conventional computational loops that explore a user-defined range of C, H, and O when searching for molecular formulae that have a given exact mass. The LMM-based algorithm has been coupled with a combinatorial algorithm that uses nested loops for N, P, S, and 13C to assign molecular formulae. The resulting program is more than 1700 times faster than its brute-force counterpart that uses nested loops for all elements, and both programs yield identical output files. The new LMM-based program is 1050 times faster than the open-source program HR2, 60 times faster than Molecular Formula Calculator, and 3.6 times faster than MassCalc/FormCalc.