Effective Derivatization of Indole Compounds in Negative Ion Chemical Ionization Mass Spectrometry

Abstract

Hunt et al. went on to show considerable increases in negtive ion currents relative to positive ion currents for compounds with high electron affinity. In order to use the negative ion chemical ionization (NICI) mass spectrometry for metabolic studies of tryptophan and its metabolites, basic investigation were carried out to examine the usefulness of TFA- or PFP-derivatization in NICI mass spectrometry. As a result, these derivatization was confirmed to be very effective with respect to enhancing sensitivity, favorable fragmentation and other practical characteristics.