DERIVATIZATION FOR ELECTROSPRAY-IONIZATION MASS-SPECTROMETRY - 3 - ELECTROCHEMICALLY IONIZABLE DERIVATIVES

In this paper, the use of ferrocene-based ''electrochemically ionizabl e'' derivatives to enhance ES-MS analysis of simple alcohols, sterols, and phenols is discussed. These derivatives are designed to take adva ntage of the electrolysis process inherent to operation of the ES ion source for selective ionization. Derivatization procedures, electroche mical character of the derivatives, and the ES-MS operational paramete rs necessary to maximize electrochemical ionization and to enhance gas -phase detection are presented with reference to ferrocenecarbamate es ter derivatives of a variety of alcohol standards, as well as the ferr oceneboronate derivative of the diol, pinacol. Tandem mass spectrometr ic analysis of the derivatives (precursor and product ion spectra) is shown to provide derivative confirmation, enhanced detection, and addi tional analyte structure information. The utility of this derivatizati on approach for the selective detection of alcohols in complicated mix tures is demonstrated using a saw palmetto (Serenoa repens) fruit extr act known to contain a variety of alcohols at low levels.