title: Mass spectrometric and tandem mass spectrometric behavior of nitrocatechol glucuronides: a comparison of atmospheric pressure chemical ionization and electrospray ionization.
abstract: The mass spectrometric (MS) and tandem mass spectrometric (MS/MS) behavior of six nitrocatechol-type glucuronides using atmospheric pressure chemical ionization (APCI) and electrospray ionization (ESI) was systematically studied, and the effect of operation parameters on the fragmentations are presented. The positive ion APCI- and ESI-MS spectra showed an intense protonated molecule and the respective negative ion spectra a deprotonated molecule with minimal fragmentation. The main fragment ions in the MS/MS spectra of the protonated and deprotonated molecules were [M + H - Glu]+ and [M - H - Glu]-, respectively, formed by the loss of the glucuronide moiety. The measured limits of detection indicated that ESI is a significantly more efficient ionization method than APCI in the negative and positive ion modes for the compounds studied. MS/MS was found to be less sensitive, but more reliable and simple than MS due to the absence of chemical noise.
authors.affiliation: Department of Pharmacy, University of Helsinki, Finland.
authors.forename: H
authors.initials: H
authors.lastname: Keski-Hynnilä
authors.forename: L
authors.initials: L
authors.lastname: Luukkanen
authors.forename: J
authors.initials: J
authors.lastname: Taskinen
authors.forename: R
authors.initials: R
authors.lastname: Kostiainen
mesh_terms: D000465:Algorithms; D005965:Glucuronates / Q000032:analysis* / Q000652:urine; D006801:Humans; D013058:Mass Spectrometry
chemical_list: D005965:Glucuronates