title: Fast graphically inspired algorithm for assignment of molecular formulae in ultrahigh resolution mass spectrometry.
abstract: 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 (13)C 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.
authors: †Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States.|‡Department of Chemistry, Ball State University, Muncie, Indiana 47306, United States.
authors: Nelson W
authors: NW
authors: Green
authors: ‡Department of Chemistry, Ball State University, Muncie, Indiana 47306, United States.
authors: E Michael
authors: EM
authors: Perdue