Evaluation of Molecular Isotope Patterns for Elemental Composition Identification on a Unit Resolution Quadrupole Mass Spectrometer

摘要

Data acquisition in profile mode on a unit resolution mass spectrometer and processing by means of MassWorks~(TM) provide "best line shape" function for mass standards such as PFTBA. The "best line shape" function can be used for internal mass spectral calibration, in order to determine accurate masses and elemental compositions via CLIPS. The CLIPS feature also provide an automated comparison of pure and overlapping isotope patterns against theoretical profiles. In the absence of fragment ions, two accurate masses should be reported, either from the molecular ion and its adduct or from two adducts. A theoretical mass spectrum with known percent similarity must be provided when reporting accurate masses for compounds containing elements with complex isotope patterns, such as chlorine, to support elemental composition assignment.