title: Chemical ionization mass spectrometry using carbon nanotube field emission electron sources.
abstract: A novel chemical ionization (CI) source has been developed based on a carbon nanotube (CNT) field emission electron source. The CNT-based electron source was evaluated and compared with a standard filament thermionic electron source in a commercial explosives trace detection desktop mass spectrometer. This work demonstrates the first reported use of a CNT-based ion source capable of collecting CI mass spectra. Both positive and negative modes were investigated. Spectra were collected for a standard mass spectrometer calibration compound, perfluorotributylamine (PFTBA), as well as trace explosives including trinitrotoluene (TNT), Research Department explosive (RDX), and pentaerythritol tetranitrate (PETN). The electrical characteristics, lifetime at operating pressure, and power requirements of the CNT-based electron source are reported. The CNT field emission electron sources demonstrated an average lifetime of 320 h when operated in constant emission mode under elevated CI pressures. The ability of the CNT field emission source to cycle on and off can provide enhanced lifetime and reduced power consumption without sacrificing performance and detection capabilities. Graphical Abstract ᅟ.
authors.affiliation: Department of Electrical and Computer Engineering, Duke University, Durham, NC, 27708, USA. ejr18@duke.edu.
authors.forename: Erich J
authors.initials: EJ
authors.lastname: Radauscher
authors.affiliation: FLIR Systems, Inc., West Lafayette, IN, 47906, USA.
authors.forename: Adam D
authors.initials: AD
authors.lastname: Keil
authors.affiliation: FLIR Systems, Inc., West Lafayette, IN, 47906, USA.
authors.forename: Mitch
authors.initials: M
authors.lastname: Wells
authors.affiliation: Department of Electrical and Computer Engineering, Duke University, Durham, NC, 27708, USA.
authors.forename: Jason J
authors.initials: JJ
authors.lastname: Amsden
authors.affiliation: Engineering and Applied Physics Division, RTI International, Research Triangle Park, NC, 27709, USA.
authors.forename: Jeffrey R
authors.initials: JR
authors.lastname: Piascik
authors.affiliation: Department of Electrical and Computer Engineering, Duke University, Durham, NC, 27708, USA.
authors.forename: Charles B
authors.initials: CB
authors.lastname: Parker
authors.affiliation: Department of Electrical and Computer Engineering, Duke University, Durham, NC, 27708, USA.|Engineering and Applied Physics Division, RTI International, Research Triangle Park, NC, 27709, USA.
authors.forename: Brian R
authors.initials: BR
authors.lastname: Stoner
authors.affiliation: Department of Electrical and Computer Engineering, Duke University, Durham, NC, 27708, USA.
authors.forename: Jeffrey T
authors.initials: JT
authors.lastname: Glass
keywords: CNT; Carbon nanotube; Chemical ionization; Explosives; Field emission; Field emitter; Mass spectrometry