title: LC-electron capture-APCI(-)-MS determination of nitrobenzoxadiazole derivatives.
abstract: Nitrobenzoxadiazole (NBD) derivatives are determined with limits of detection ranging down to 20 nmol l(-1) using liquid chromatography-mass spectrometry (LC-MS) with electron capture (EC) ionisation. An atmospheric pressure chemical ionisation (APCI) interface operated in the negative ion mode is used as ionisation source. Amine derivatives of 4-chloro-7-nitro-2,1,3-benzoxadiazole (NBDCl) as well as the isocyanate derivatives of 4-nitro-7-piperazino-2,1,3-nitrobenzoxadiazole (NBDPZ) have been analysed using this technique. The parameters favouring electron capture mechanisms have been investigated thoroughly under consideration of the competing mechanism of deprotonation to allow a better understanding of the electron capture process and to improve selectivity of the analysis.
authors.affiliation: University of Twente, Department of Chemical Analysis and MESA+ Research Institute, PO Box 217, 7500 AE Enschede, The Netherlands.
authors.forename: Heiko
authors.initials: H
authors.lastname: Hayen
authors.forename: Nicole
authors.initials: N
authors.lastname: Jachmann
authors.forename: Martin
authors.initials: M
authors.lastname: Vogel
authors.forename: Uwe
authors.initials: U
authors.lastname: Karst
mesh_terms: D002853:Chromatography, Liquid / Q000379:methods; D004785:Environmental Pollutants / Q000032:analysis*; D010069:Oxadiazoles / Q000032:analysis*; D013057:Spectrum Analysis / Q000379:methods
chemical_list: D004785:Environmental Pollutants; D010069:Oxadiazoles