Generates sum formulas based on a given mass. The formula generator assumes
input masses to be major isotopic masses.

Generated sum formulas can be filtered by the nitrogen rule, element ratio rule, and
by element number restriction. For details on the implemented options, please see the
"seven golden rules" by Kind et al., 2007. The following excerpts are taken from the publication.

"The nitrogen rule states that an odd nominal molecular mass implies also an odd number of nitrogens.
This rule should only be used with nominal (integer) masses. When using accurate mass measurements
this rule becomes unreliable in mass ranges higher than 500 Da."

"The maximum element count can be restricted in a heuristic manner by using the provided sets of element
minima und maxima that were derived from NIST and Wiley mass spectra and DNP entries. Maximum element counts
are defined for the mass ranges at smaller 500 Da, 1000 Da, 2000 Da, 3000 Da by taking the higher value found
in either of the two databases."

"More than 99.7% of all formulas were included with H/C ratios between 0.2–3.1. This range is called the 'common range'.
However, a number of chemical classes fall out of this range. The 'extended ranges' covers 99.99% of all formulas in
the used database (H vs C 0.1–6). There are extreme cases for which rules of typical H vs C ratios may be overridden, e.g.
for the study of fullerenes, which have an extremely low hydrogen/carbon ratio such as in C78H12Cl2N2."

Sum formulas that do not contain a single Carbon atom are always included.

DISABLED Options: 'All elements' and 'Exclude elements' are currently not supported because the
matrix required for the calculation exceeds the memory limit of the virtual machine: Math.pow(2, size).

- Column with masses
- Mass column in input table.
- All elements (DISABLED)
- Whether to use all elements for the calculation.
- Include elements
- Whether to use a custom set of elements.
- Exclude elements (DISABLED)
- Whether to use all elements excluding a set of elements.
- Elements
- The comma-separated set of elements to be included or excluded.
- Carbon limits
- The allowed minimum and maximum number of carbon element counts.
- Hydrogen limits
- The allowed minimum and maximum number of hydrogen element counts.
- Other limits
- The allowed minimum and maximum number of other element counts.
- Mass tolerance
- The mass tolerance in 'amu'.
- Nitrogen rule
- Apply the nitrogen rule.
- Element ratio rule
- Apply the element ratio check rule.
- Element restriction
- Apply element occurrence restrictions.

- This node has no views

- No workflows found

- No links available

You want to see the source code for this node? Click the following button and we’ll use our super-powers to find it for you.

To use this node in KNIME, install the extension KNIME-CDK from the below update site following our NodePit Product and Node Installation Guide:

v4.7

A zipped version of the software site can be downloaded here.

Do you have feedback, questions, comments about NodePit, want to support this platform, or want your own nodes or workflows listed here as well? Do you think, the search results could be improved or something is missing? Then please get in touch! Alternatively, you can send us an email to mail@nodepit.com, follow @NodePit on Twitter, or chat on Gitter!

**Please note that this is only about NodePit. We do not provide general support for KNIME — please use the KNIME forums instead.**