Browse reference spectra from the USGS Spectral Library Version 7 and other curated sources. Each spectrum includes interactive plots, metadata, and downloadable data.
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| Formula | Modality | Category | Source | ||
|---|---|---|---|---|---|
| 4-OXO-4H-PYRIDO(1,2-A)PYRIMIDINE-3-ACETICACID | C10H8N2O3 | Mass Spec | Chemical | MassBank | |
| 4-OXO-4H-PYRIDO(1,2-A)PYRIMIDINE-3-ACETICACID ETHYL ESTER | C12H12N2O3 | Mass Spec | Chemical | MassBank | |
| 4-OXO-4H-PYRIDO(1,2-A)PYRIMIDINE-3-CARBOXYLIC ACID ETHYL ESTER | C11H10N2O3 | Mass Spec | Chemical | MassBank | |
| 4-OXO-4H-PYRIDO(1,2-A)PYRIMIDINE-3-PROPIONIC ACID ETHYL ESTER | C13H14N2O3 | Mass Spec | Chemical | MassBank | |
| 4-OXO-6,7,8,9-TETRAHYDRO-4H-PYRIDO(1,2-A)PYRIMIDINE-3-ACETIC ACID | C10H12N2O3 | Mass Spec | Chemical | MassBank | |
| 4-OXO-6,7,8,9-TETRAHYDRO-4H-PYRIDO(1,2-A)PYRIMIDINE-3-ACETIC ACID ETHYL ESTER | C12H16N2O3 | Mass Spec | Chemical | MassBank | |
| 4-OXO-6,7,8,9-TETRAHYDRO-4H-PYRIDO(1,2-A)PYRIMIDINE-3-CARBOXYLIC ACID ETHYL ESTER | C11H14N2O3 | Mass Spec | Chemical | MassBank | |
| 4-OXOPENTANOIC ACID TRIMETHYLSILYL ESTER | C8H16O3Si | Mass Spec | Chemical | MassBank | |
| 4-OXOVALERIC ACID METHYL ESTER | C6H10O3 | Mass Spec | Chemical | MassBank | |
| 4-Octylbenzenesulfonic acid | C14H22O3S | Mass Spec | Chemical | MassBank | |
| 4-Octylphenol | C14H22O | Mass Spec | Environmental | MassBank | |
| 4-Oxo-4-[3-(trifluoromethyl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H9-yl]-1-(2,4,5-trifluorophenyl)butan-2-one | C16H12F6N4O2 | Mass Spec | Chemical | MassBank | |
| 4-Oxohexanoate | C6H10O3 | Mass Spec | Chemical | MassBank | |
| 4-Oxopentanoic acid | C5H8O3 | Mass Spec | Chemical | MassBank | |
| 4-Oxypiperidol | C9H18NO2 | Mass Spec | Pharmaceutical | MassBank | |
| 4-PENTEN-1-OL | C5H10O | Mass Spec | Chemical | MassBank | |
| 4-PENTENENITRILE | C5H7N | Mass Spec | Chemical | MassBank | |
| 4-PENTENYL ISOTHIOCYANATE | C6H9NS | Mass Spec | Chemical | MassBank | |
| 4-PENTYLBENZOIC ACID TRIMETHYLSILYL ESTER | C15H24O2Si | Mass Spec | Chemical | MassBank | |
| 4-PENTYLCYCLOHEXANOL | C11H22O | Mass Spec | Chemical | MassBank | |
| 4-PENTYLPYRIDINE | C10H15N | Mass Spec | Chemical | MassBank | |
| 4-PHENOXYBENZYL BENZOATE | C20H16O3 | Mass Spec | Chemical | MassBank | |
| 4-PHENOXYBENZYLALCOHOL | C13H12O2 | Mass Spec | Chemical | MassBank | |
| 4-PHENYL-2-(2-OXOPROPYL)FURAN | C13H12O2 | Mass Spec | Chemical | MassBank | |
| 4-PHENYL-2-(N'-PHENYLUREIDO)PYRIMIDINE-1-OXIDE | C17H14N4O2 | Mass Spec | Chemical | MassBank | |
| 4-PHENYL-3-BUTEN-2-ONE | C10H10O | Mass Spec | Chemical | MassBank | |
| 4-PHENYL-4-METHYL-2-PENTANONE | C12H16O | Mass Spec | Chemical | MassBank | |
| 4-PHENYL-6-HEPTYN-2-ONE | C13H14O | Mass Spec | Chemical | MassBank | |
| 4-PHENYLAMINO-2(5H)-FURANONE | C10H9NO2 | Mass Spec | Chemical | MassBank | |
| 4-PHENYLAZOBENZOIC ACID METHYL ESTER | C14H12N2O2 | Mass Spec | Chemical | MassBank | |
| 4-PHENYLAZOBENZOIC ACID TRIMETHYLSILYL ESTER | C16H18N2O2Si | Mass Spec | Chemical | MassBank | |
| 4-PHENYLBENZOIC ACID | C13H10O2 | Mass Spec | Chemical | MassBank | |
| 4-PHENYLBENZYLALCOHOL | C13H12O | Mass Spec | Chemical | MassBank | |
| 4-PHENYLBICYCLO(3.2.2)NONA-3,6-DIEN-2-ONE | C15H14O | Mass Spec | Chemical | MassBank | |
| 4-PHENYLBUTYRIC ACID | C10H12O2 | Mass Spec | Chemical | MassBank | |
| 4-PHENYLBUTYRIC ACID METHYL ESTER | C11H14O2 | Mass Spec | Chemical | MassBank | |
| 4-PHENYLBUTYRIC ACID TRIMETHYLSILYL ESTER | C13H20O2Si | Mass Spec | Chemical | MassBank | |
| 4-PHENYLDECANE | C16H26 | Mass Spec | Chemical | MassBank | |
| 4-PHENYLDODECANE | C18H30 | Mass Spec | Chemical | MassBank | |
| 4-PHENYLPYRIDINE | C11H9N | Mass Spec | Chemical | MassBank | |
| 4-PHENYLTRIDECANE | C19H32 | Mass Spec | Chemical | MassBank | |
| 4-PHENYLUNDECANE | C17H28 | Mass Spec | Chemical | MassBank | |
| 4-PICOLYL ACETATE | C8H9NO2 | Mass Spec | Chemical | MassBank | |
| 4-PIPECOLINE | C6H13N | Mass Spec | Chemical | MassBank | |
| 4-PIPEROYLMORPHOLINE | C16H17NO4 | Mass Spec | Chemical | MassBank | |
| 4-PROPOXYBENZOIC ACID METHYL ESTER | C11H14O3 | Mass Spec | Chemical | MassBank | |
| 4-PROPOXYBENZOIC ACID TRIMETHYLSILYL ESTER | C13H20O3Si | Mass Spec | Chemical | MassBank | |
| 4-PROPYL-4,4A,5,6,7,8-HEXAHYDRO-2(3H)-NAPHTHALENONE | C13H20O | Mass Spec | Chemical | MassBank | |
| 4-PROPYLBENZOIC ACID METHYL ESTER | C11H14O2 | Mass Spec | Chemical | MassBank | |
| 4-PROPYLPYRIDINE | C8H11N | Mass Spec | Chemical | MassBank |