Dopant-Assisted Negative Photoionization Ion Mobility Spectrometry for Sensitive Detection of Explosives
Ion mobility spectrometry (IMS) is a key trace detection technique for explosives and the development of a simple, stable, and efficient nonradioactive ionization source is highly demanded. A dopant-assisted negative photoionization (DANP) source has been developed for IMS, which uses a commercial VUV krypton lamp to ionize acetone as the source of electrons to produce negative reactant ions in air. With 20 ppm of acetone as the dopant, a stable current of reactant ions of 1.35 nA was achieved. The reactant ions were identified to be CO3–(H2O)n (K0 = 2.44 cm2 V–1 s–1) by atmospheric pressure time-of-flight mass spectrometry, while the reactant ions in 63Ni source were O2–(H2O)n (K0 = 2.30 cm2 V–1 s–1). Finally, its capabilities for detection of common explosives including ammonium nitrate fuel oil (ANFO), 2,4,6-trinitrotoluene (TNT), N-nitrobis(2-hydroxyethyl)amine dinitrate (DINA), and pentaerythritol tetranitrate (PETN) were evaluated, and the limits of detection of 10 pg (ANFO), 80 pg (TNT), and 100 pg...
Shasha Cheng; Jian Dou; Weiguo Wang; Chuang Chen; Lei Hua; Qinghua Zhou; Keyong Hou; Jinghua Li; Haiyang Li
In this Perspective, we present an overview of recent fundamental studies on the nature of the interaction between individual metal atoms and metal clusters and the conjugated surfaces of graphene and carbon nanotube with a particular focus on the electronic structure and chemical bonding a ... more
The first [ECE]Ni(II) pincer complexes with E = SiII and E = GeII metallylene donor arms were synthesized via C–X (X = H, Br) oxidative addition, starting from the corresponding [EC(X)E] ligands. These novel complexes were fully characterized (NMR, MS, and XRD) and used as catalyst for Ni-c ... more
Rohm and Haas Powder Coatings is delighted to announce that its Reading, Pennsylvania, facility is the first site in the world to receive the RCMS® Site Certification awarded by the American Chemical Council (ACC).
When Raj Gupta, Chairman and CEO of Rohm and Haas Company, became Chairman ... more