mass spectroscopy calculator - SERP Analysis

https://www.sisweb.com/mstools/isotope.htm

https://ms.epfl.ch/applications/theoretical-calculations/

https://warwick.ac.uk/fac/sci/chemistry/research/barrow/barrowgroup/calculators/

https://www.sisweb.com/referenc/tools/exactmass.htm

https://www.envipat.eawag.ch/

https://www.protpi.ch/Calculator/MassSpecSimulator

https://fiehnlab.ucdavis.edu/staff/kind/metabolomics/ms-adduct-calculator/

https://warwick.ac.uk/fac/sci/chemistry/research/barrow/barrowgroup/calculators/mass_errors/

http://www.chemcalc.org/mf-finder

https://www.nist.gov/mml/biomolecular-measurement/mass-spectrometry-data-center/nist-glyco-mass-calculator