title: Derivatization for electrospray ionization mass spectrometry. 3. Electrochemically ionizable derivatives.
abstract: In this paper, the use of ferrocene-based "electrochemically ionizable" derivatives to enhance ES-MS analysis of simple alcohols, sterols, and phenols is discussed. These derivatives are designed to take advantage of the electrolysis process inherent to operation of the ES ion source for selective ionization. Derivatization procedures, electrochemical character of the derivatives, and the ES-MS operational parameters necessary to maximize electrochemical ionization and to enhance gas-phase detection are presented with reference to ferrocenecarbamate ester derivatives of a variety of alcohol standards, as well as the ferroceneboronate derivative of the diol, pinacol. Tandem mass spectrometric analysis of the derivatives (precursor and product ion spectra) is shown to provide derivative confirmation, enhanced detection, and additional analyte structure information. The utility of this derivatization approach for the selective detection of alcohols in complicated mixtures is demonstrated using a saw palmetto (Serenoa repens) fruit extract known to contain a variety of alcohols at low levels.
authors.affiliation: Chemical and Analytical Sciences Division, Oak Ridge National Laboratory, Tennessee 37831-6365, USA. vanberkelgj@ornl.gov
authors.forename: G J
authors.initials: GJ
authors.lastname: Van Berkel
authors.forename: J M
authors.initials: JM
authors.lastname: Quirke
authors.forename: R A
authors.initials: RA
authors.lastname: Tigani
authors.forename: A S
authors.initials: AS
authors.lastname: Dilley
authors.forename: T R
authors.initials: TR
authors.lastname: Covey
mesh_terms: D000438:Alcohols / Q000032:analysis* / Q000737:chemistry; D004563:Electrochemistry; D005296:Ferrous Compounds / Q000737:chemistry; D013058:Mass Spectrometry / Q000379:methods*; D000075163:Metallocenes; D010636:Phenols / Q000032:analysis* / Q000737:chemistry; D010936:Plant Extracts / Q000302:isolation & purification; D010946:Plants, Medicinal; D013261:Sterols / Q000032:analysis* / Q000737:chemistry
chemical_list: D000438:Alcohols; D005296:Ferrous Compounds; D000075163:Metallocenes; D010636:Phenols; D010936:Plant Extracts; D013261:Sterols; C078996:ferrocene carbamate