Sentence examples for molecular formulas that from inspiring English sources
Second, computation time highly depends on the number of molecular formulas that have to be considered.
Decomposing the monoisotopic peak can result in a large number of candidate molecular formulas that are within the measured mass [117].
This approach is, by design, restricted to molecular formulas that are already known, and must naturally miss cases where no molecular formula is contained in a structure database.
Fig. 1 Number of molecular formulas that match the mass of some precursor peak in the Agilent and GNPS dataset, using the maximum of 10 ppm and 2 mDa as allowed mass deviation.
The structural elucidation of compounds not included in the libraries is hampered by hard ionization techniques, which often do not allow the identification of the molecular ion [51], and by the sometimes high number of molecular formulas that can be attributed to low-resolution mass spectra [52].
If we restrict our search to molecular formulas that are contained in PubChem, and again rank molecular formula candidates by mass difference to the measured parent mass, we find the correct molecular formula for 17.1 % of the instances in top rank, and 59.8 % in the top 5.
Molecular Formula A molecular formula that captures the types and counts of atoms present in a molecule.
FTs can be used to identify the molecular formula of a compound [34]: for each molecular formula decomposition that is within the given mass accuracy of the parent peak, find the FT rooted with this molecular formula that has maximum score.
Each molecule was predicted by HRMS to have a molecular formula that was distinct from any previously isolated pentangular polyphenol natural product.
Furthermore, prior probabilities are chosen conservatively, so that "unlikely" molecular formulas are penalized only slightly: if there is sufficient MS/MS data, SIRIUS 3 will "overrule" these priors, returning a molecular formula that violates one or even several prior assumptions.
By this, the number of carbon, nitrogen as well as sulfur atoms can be determined upfront, and the number of potential molecular formula that we have to consider, is reduced considerably.
