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Compound Molecular Formula Determination and/or Confirmation


Accurate mass analysis (typical accuracy within 0.003 Da vs theoretical value) is typically performed by an IMSERC staff member. IMSERC is able to perform accurate mass analysis using a wide variety of ionization techniques which include ESI, APCI, APPI, LIFTI, EI and MALDI. IMSERC’s mission is to perform onsite analysis for all molecular compounds synthesized in the department and makes this service available to outside users as well. Stable compounds are usually processed in order received and initial data returned within 2 business days. Customers with air or time sensitive samples should contact an IMSERC staff member before proceeding. External customers must receive approval before shipping samples to IMSERC or the package will be returned unopened. Depending on ionization technique, users will receive a 3 part report containing a full representative spectrum of the compound, a computer generated list of likely formulas for the monoisotopic peak (i.e. formula match) and either a zoomed in spectrum showing isotopic distribution (soft ionization technique) or fragmentation (hard ionization techniques). Customers requesting purity analysis and chromatographic separation should request purity analysis of sample using LC/UV/MS or GCMS.

Typical Data

Below are exampl spectra acquired for a molecule of interest shown in the full spectrum (left),  a zoom in of the isotopic pattern for the psuedomolecular ion for the molecule (middle), and a table assigning match criteria to the isotopic envelope, evaluating the match based on intensity, exact mass (to the 4th decimal place), and spacing of the mass peaks (bottom).



  • Determine the molecular formula of a compound.
  • Confirm the identity of a compound of interest.
  • Include accurate mass analysis of compounds, which is needed for most publications involving molecule synthesis or identifications of unknowns.

If you are interested in utilizing any of these applications for your research Start a project