Phenolic acid mass spectra

ESI-MS has emerged as a powerful technique for the characterization of biomolecules, and is the most versatile ionization technique in existence today. This highly sensitive and soft ionization technique allows mass spectrometric analysis of thermolabile, non-volatile, and polar compounds and produces intact ions from large and complex species in solution. In addition, it has the ability to introduce liquid samples to a mass detector with minimum manipulation. Volatile acids (such as formic acid and acetic acid) are often added to the mobile phase as well to protonate anthocyanins. A chromatogram with only the base peak for every mass spectrum provides more readily interpretable data because of fewer interference peaks. Cleaner mass spectra are achieved if anthocyanins are isolated from other phenolics by the use of C18 solid phase purification. - ... 

Confidence level for match of mass spectrum of known phenolic acids. 

All classes of organic compounds each compound identified by its mass spectrum Mass spectrometer Gas chromatography VOCs (EPA 8260) and SVOCs (EPA 8270) dioxins/furans (EPA 8280, EPA 8290) CLP SOW for organic analysis Liquid chromatography solvent-extratable nonvolatile compounds (EPA 8321, EPA 8325) Interferences from Oily matrices Trace level laboratory artifacts Interferences from Organic acids Phenols Trace level laboratory artifacts... 

The bark of O. viellardii Guill. afforded seven known alkaloids and an eighth new alkaloid, ellipticine JV-oxide (266) (120). In the mass spectrum the molecular ion was observed at m/e 262, indicating the presence of an additional oxygen compared to ellipticine (267). The oxygen was not in the form of a carbonyl (IR) or phenolic (UV) function. Reduction with zinc and hydrochloric acid gave ellipticine (267), identical with the authentic alkaloid. Attempts to produce the N-oxide with classical reagents failed. 

---