To verify how the results for [DOPAC-H] -generalize, a validation set of 189 experimental IRIS spectra was subjected to spectral matching against the in silico IR library spectra, analogous to the analysis for DOPAC. The ranking of each IR spectrum match, as well as spectral plots similar to those for DOPAC are available in the Supporting Information. Figure shows how well the metabolites are identified based on their IRIS spectrum and exact m/z, plotting the percentage of correctly identified metabolites in the top k for increasing k. A total of 142 (75%) correct metabolite identifications is achieved when a single experimental IR spectrum is used (red solid trace); 97% of the metabolites are among the top 5 ranked structures. Annotating the experimental IR spectrum to a random isomeric entry from the spectral library correctly identifies 33% of the metabolites (dashed trace), which is relatively high due to entries in the database with only one or a few isomeric structures.