The CNL model was built based on the MassBank EU and MassBank of North America (MoNA) database entries that were obtained using electrospray ionization in positive mode with a mass resolution ≥ 5000, including any type of mass analyzer (i.e., QTof and Orbitrap) and collision energy. Where multiple entries for a single chemical were found, the spectra were merged to ensure that the CNLs for each compound would have equal contribution to the model, using a 0.001 Da mass window. It should be noted that 0.001 Da was not assumed to be the inherent uncertainty of the data and was used as bin width for generation of average spectra. To obtain the CNLs for each compound, the fragment m/z values from the merged spectra were subtracted from the precursor ion mass. This resulted in reducing the 81,417 individual spectra to 4205 merged CNL spectra for unique chemical constituents.