Heuristically Determined Formula by Mass
This page is meant to be a tool for mass spectrometry. The formula masses for over
400 million formulas have been calculated and stored. Because of the large combinatorial
problem, formulas with natural abundance masses less than 2000 daltons were calculated and
heuristic rules were used to limit the formulas to those that are most likely to be
found in nature.
Please take a moment to review the input formats.
Because of the large file sizes and http post constraints, limit your query list to 500
entries or less. Very large files do not get transferred.
The results of your query will be deposited into a downloadable, tab
seperated file and posted below. Please be aware that large queries may
take some time to complete.