title: Direct detection of explosives on solid surfaces by low temperature plasma desorption mass spectrometry.
abstract: In this paper, we have constructed a low temperature plasma (LTP) probe using dielectric barrier discharge (DBD) and employed it for the detection of explosives on a variety of substrates under ambient conditions. Upon discharge, a transient, low-temperature non-equilibrium plasma comprising ions, electrons and metastable atoms are generated between the electrodes. Three common explosives, 2,4,6-trinitrotoluene (TNT), hexahydro-1,3,5-trinitro-1,3,5-trinitro-1,3,5-triazine (RDX), and pentaerythritol tetranitrate (PETN), were directly desorbed and ionized from solid surfaces, followed by subsequent analysis using the mass spectrometer in the negative ion mode. Limits of detection (LODs) were 500 fg for TNT, 1 pg for RDX, and 500 fg for PETN. The reliability of the method was characterized by a successful analysis of a mixture of the three explosives. The ion source also allowed direct detection of trace explosives on both conductive and non-conductive substrates, thus expanding the applicability of low temperature plasma desorption mass spectrometry.
authors.affiliation: Department of Chemistry, Key Laboratory for Atomic and Molecular Nanosciences of Education Ministry, Tsinghua University, 100084, Beijing, PR China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhang
authors.forename: Xiaoxiao
authors.initials: X
authors.lastname: Ma
authors.forename: Sichun
authors.initials: S
authors.lastname: Zhang
authors.forename: Chengdui
authors.initials: C
authors.lastname: Yang
authors.forename: Zheng
authors.initials: Z
authors.lastname: Ouyang
authors.forename: Xinrong
authors.initials: X
authors.lastname: Zhang
mesh_terms: D004563:Electrochemistry / Q000379:methods; D004785:Environmental Pollutants / Q000032:analysis*; D053834:Explosive Agents / Q000032:analysis*; D013058:Mass Spectrometry / Q000379:methods*; D010417:Pentaerythritol Tetranitrate / Q000032:analysis; D012680:Sensitivity and Specificity; D013696:Temperature; D014227:Triazines / Q000032:analysis; D014303:Trinitrotoluene / Q000032:analysis
chemical_list: D004785:Environmental Pollutants; D053834:Explosive Agents; D014227:Triazines; D010417:Pentaerythritol Tetranitrate; D014303:Trinitrotoluene; C009160:cyclonite