Zhang Yan, Ma Xiaoxiao, Zhang Sichun, Yang Chengdui, Ouyang Zheng, Zhang Xinrong
Department of Chemistry, Key Laboratory for Atomic and Molecular Nanosciences of Education Ministry, Tsinghua University, 100084, Beijing, PR China.
Analyst. 2009 Jan;134(1):176-81. doi: 10.1039/b816230a. Epub 2008 Nov 25.
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.
在本文中，我们利用介质阻挡放电（DBD）构建了一种低温等离子体（LTP）探针，并将其用于在环境条件下检测各种基底上的爆炸物。放电时，电极之间会产生由离子、电子和亚稳态原子组成的瞬态低温非平衡等离子体。三种常见爆炸物，2,4,6-三硝基甲苯（TNT）、六氢-1,3,5-三硝基-1,3,5-三嗪（RDX）和季戊四醇四硝酸酯（PETN），从固体表面直接解吸并电离，随后使用质谱仪以负离子模式进行分析。TNT的检测限（LOD）为500 fg，RDX为1 pg，PETN为500 fg。该方法的可靠性通过对这三种爆炸物混合物的成功分析得以表征。该离子源还允许直接检测导电和非导电基底上的痕量爆炸物，从而扩大了低温等离子体解吸质谱的适用性。
