Ferrocene-based electroactive derivatizing reagents for the rapid selective screening of alcohols and phenols in natural product mixtures using electrospray-tandem mass spectrometry

The alcohols and phenols of oil of cloves, lemon oil, rose absolut, and oil of peppermint were derivatized with ferroceneoyl azide to generate their f erroceneoyl carbamates. These derivatives are selectively detected at the a ttomole level, in nanomolar concentrations by electrospray-tandem mass spec trometry (ES-MS/MS) without the need for sample cleanup. The ES-MS/MS analy ses of the four essential oils revealed all the expected alcohols, and, in the case of lemon oil, it detected alpha-terpineol as a trace component tha t was not readily observed by GC-MS. The ES-MS/MS analyses complements the more conventional GC-MS analysis. The ES-MS method has the advantage of spe ed, selectivity, and sensitivity over GCMS for detection of a targeted alco hol of a specific mass or structural type. The ES-MS method does not requir e a chromatographic separation of the components to accomplish its task. In contrast, GC-MS remains the preferred method for the determination of the total constituents of an oil. The ES-MS method may produce artifact ions, e specially if the sample is wet and an excess of the ferroceneoyl azide is u sed; however, the artifacts did not interfere with the analyses.