title: Integrated explosive preconcentrator and electrochemical detection system for 2,4,6-trinitrotoluene (TNT) vapor.
abstract: This article reports on an integrated explosive-preconcentration/electrochemical detection system for 2,4,6-trinitrotoluene (TNT) vapor. The challenges involved in such system integration are discussed. A hydrogel-coated screen-printed electrode is used for the detection of the thermally desorbed TNT from a preconcentration device using rapid square wave voltammetry. Optimization of the preconcentration system for desorption of TNT and subsequent electrochemical detection was conducted yielding a desorption temperature of 120 degrees C under a flow rate of 500 mL min(-1). Such conditions resulted in a characteristic electrochemical signal for TNT representing the multi-step reduction process. Quantitative measurements produced a linear signal dependence on TNT quantity exposed to the preconcentrator from 0.25 to 10 microg. Finally, the integrated device was successfully demonstrated using a sample of solid TNT located upstream of the preconcentrator.
authors.affiliation: Department of Nanoengineering, University of California-San Diego, La Jolla, CA 92093-0448, USA.
authors.forename: Karel
authors.initials: K
authors.lastname: Cizek
authors.forename: Chad
authors.initials: C
authors.lastname: Prior
authors.forename: Chongdee
authors.initials: C
authors.lastname: Thammakhet
authors.forename: Michal
authors.initials: M
authors.lastname: Galik
authors.forename: Kevin
authors.initials: K
authors.lastname: Linker
authors.forename: Ray
authors.initials: R
authors.lastname: Tsui
authors.forename: Avi
authors.initials: A
authors.lastname: Cagan
authors.forename: John
authors.initials: J
authors.lastname: Wake
authors.forename: Jeff
authors.initials: J
authors.lastname: La Belle
authors.forename: Joseph
authors.initials: J
authors.lastname: Wang
mesh_terms: D004563:Electrochemistry / Q000295:instrumentation* / Q000379:methods; D053834:Explosive Agents / Q000032:analysis / Q000737:chemistry*; D014303:Trinitrotoluene / Q000032:analysis / Q000737:chemistry*; D014835:Volatilization
chemical_list: D053834:Explosive Agents; D014303:Trinitrotoluene