Browse reference spectra from the USGS Spectral Library Version 7 and other curated sources. Each spectrum includes interactive plots, metadata, and downloadable data.
Have an unknown spectrum? Match it against this entire library with HQI similarity scoring — no install, no data leaves your machine.
Identify My SampleLearn more about how spectral matching works, HQI scoring, and building a personal reference library on the Spectral Library Search page.
| Formula | Modality | Category | Source | ||
|---|---|---|---|---|---|
| 3'-BROMOACETOPHENONE | C8H7BrO | Mass Spec | Chemical | MassBank | |
| 3'-BROMOFLAVONOL | C15H9BrO3 | Mass Spec | Chemical | MassBank | |
| 3'-CHLOROFLAVONE | C15H9ClO2 | Mass Spec | Chemical | MassBank | |
| 3'-CHLOROFLAVONOL | C15H9ClO3 | Mass Spec | Chemical | MassBank | |
| 3'-Deoxycapsanthin | C40H56O2 | Mass Spec | Chemical | MassBank | |
| 3'-Dephosphocoenzyme A | C21H35N7O13P2S | Mass Spec | Chemical | MassBank | |
| 3'-Epigobiusxanthin | C40H54O3 | Mass Spec | Natural product | MassBank | |
| 3'-HYDROXY-2',4'-DIMETHOXYACETOPHENONE | C10H12O4 | Mass Spec | Chemical | MassBank | |
| 3'-HYDROXYACETOPHENONE | C8H8O2 | Mass Spec | Chemical | MassBank | |
| 3'-Hydroxyflavone | C15H10O3 | Mass Spec | Natural product | MassBank | |
| 3'-METHOXY-4',5,7-TRIHYDROXYFLAVONOL | C16H12O7 | Mass Spec | Chemical | MassBank | |
| 3'-Methyl-4-dimethylaminoazobenzene | C15H17N3 | Mass Spec | Chemical | MassBank | |
| 3'-NITROACETOPHENONE | C8H7NO3 | Mass Spec | Chemical | MassBank | |
| 3'-O-Didehydrolutein | C40H54O2 | Mass Spec | Chemical | MassBank | |
| 3(S)-CITRONELAL | C10H18O | Mass Spec | Chemical | MassBank | |
| 3(S)-CITRONELOL | C10H20O | Mass Spec | Chemical | MassBank | |
| 3,1-BENZOXAZEPINE-2-CARBONITRILE | C10H6N2O | Mass Spec | Chemical | MassBank | |
| 3,12-Dioxo-5a-cholan-24-oic acid | C24H36O4 | Mass Spec | Natural product | MassBank | |
| 3,12-Dioxo-5b-cholan-24-oic acid | C24H36O4 | Mass Spec | Natural product | MassBank | |
| 3,15-Diacetyldeoxynivalenol | C19H24O8 | Mass Spec | Metabolite | MassBank | |
| 3,17ALPHA-DI-O-TRIMETHYLSILYLESTRADIOL | C24H40O2Si2 | Mass Spec | Chemical | MassBank | |
| 3,17BETA-DI-O-TRIMETHYLSILYLESTRADIOL | C24H40O2Si2 | Mass Spec | Chemical | MassBank | |
| 3,3',4',5,5',7-hexahydroxyflavone | C15H10O8 | Mass Spec | Natural product | MassBank | |
| 3,3',4',5,7-PENTAACETOXYFLAVONE | C25H20O12 | Mass Spec | Chemical | MassBank | |
| 3,3',4',5,7-pentahydroxy flavylium | [C15H11O6]+ | Mass Spec | Natural product | MassBank | |
| 3,3',4',5,7-pentahydroxyflavone | C15H10O7 | Mass Spec | Natural product | MassBank | |
| 3,3',4',5-tetrahydroxy-7-methoxyflavone | C16H12O7 | Mass Spec | Natural product | MassBank | |
| 3,3',5,5'-TETRA-METHYL-4,4'-DICYCLOPROPYL-METHYLOXY-BIPHENYL | C24H30O2 | Mass Spec | Chemical | MassBank | |
| 3,3',5,5'-TETRAMETHYL-4,4'-DIMETHOXY-1,1'-BIPHENYL | C18H22O2 | Mass Spec | Chemical | MassBank | |
| 3,3',5,5'-Tetrabromobisphenol A | C15H12Br4O2 | Mass Spec | Environmental | MassBank | |
| 3,3',5,5'-Tetramethylbenzidine | C16H20N2 | Mass Spec | Environmental | MassBank | |
| 3,3',5-Triiodothyronine | C15H12I3NO4 | Mass Spec | Chemical | MassBank | |
| 3,3'-(1,1,3,3-Tetramethyldisiloxane-1,3-diyl)dipropan-1-amine | C10H28N2OSi2 | Mass Spec | Chemical | MassBank | |
| 3,3'-(4-Methylbenzene-1,3-diyl)bis(1,1-dimethylurea) | C13H20N4O2 | Mass Spec | Chemical | MassBank | |
| 3,3'-DICHLOROBENZIDINE | C12H10Cl2N2 | Mass Spec | Chemical | MassBank | |
| 3,3'-DINITROAZOXYBENZENE | C12H8N4O5 | Mass Spec | Chemical | MassBank | |
| 3,3'-Dimethoxybenzidine | C14H16N2O2 | Mass Spec | Environmental | MassBank | |
| 3,3'-IMINODIPROPIONITRILE | C6H9N3 | Mass Spec | Chemical | MassBank | |
| 3,3'-Iminobispropanenitrile | C6H9N3 | Mass Spec | Chemical | MassBank | |
| 3,3'-Sulphonyldianiline | C12H12N2O2S | Mass Spec | Chemical | MassBank | |
| 3,3'5,5'-TETRABROMO-2,2'-BITHIOPHENE | C8H2Br4S2 | Mass Spec | Chemical | MassBank | |
| 3,3,3-TRICHLORO-2-HYDROXY-PROPIONIC ACID-HYDRAZIDE | C3H5Cl3N2O2 | Mass Spec | Chemical | MassBank | |
| 3,3,3-TRICHLORO-2-TRIMETHYLSILOXYPROPENE | C6H11Cl3OSi | Mass Spec | Chemical | MassBank | |
| 3,3,3-TRIMETHOXY PROPIONITRILE | C6H11NO3 | Mass Spec | Chemical | MassBank | |
| 3,3,3-TRIMETHOXYPROPIONITRILE | C6H11NO3 | Mass Spec | Chemical | MassBank | |
| 3,3,4,4,5,5,6,6,7,7,8,8,8-Tridecafluorooctyl dihydrogen phosphate | C8H6F13O4P | Mass Spec | Chemical | MassBank | |
| 3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluorooctane-1-sulfonic acid | C8H5F13O3S | Mass Spec | Chemical | MassBank | |
| 3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,10-Heptadecafluorodecanesulphonic acid | C10H5F17O3S | Mass Spec | Chemical | MassBank | |
| 3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,10-Heptadecafluorodecyl dihydrogen phosphate | C10H6F17O4P | Mass Spec | Chemical | MassBank | |
| 3,3,4-TRIMETHOXY-8,8,9,9-TETRAMETHYLBICYCLO(5.2.0)NONANE-2,6-DIONE | C16H26O5 | Mass Spec | Chemical | MassBank |