Faye T, Mathurin JC, Brunot A, Tabet JC, Wells G, Fuche C
Laboratoire de Chimie Structurale Organique et Biologique, CNRS UMR 7613, Universite Pierre et Marie Curie, Paris, France.
Anal Chem. 2000 Oct 15;72(20):5063-9. doi: 10.1021/ac000172e.
Negative ion chemical ionization was carried out using a quadrupole ion trap mass spectrometer with selected reactant negative ions, primarily injected from a homemade dual EI/CI external ion source. Hence, selective ion/molecule reactions were provided according to the reaction time, which induce a greater control over bimolecular ionization mechanisms than in conventional a high-pressure ion source combined with beam instruments, where several competitive ionization processes take place mainly due to source conditions (e.g., temperature, pressure, and repeller). By selecting the reactant ions, ion/molecule reactions were specifically produced (i.e., charge exchange, proton transfer, nucleophilic substitution, and/or alpha-beta elimination) with several organic target compounds. Gas-phase reactivity of phosphorus- and nitrogen-containing compounds (such as phosphonates as representative for chemical warfare agents and phosphorothionates, phosphorodithionates, and triazines for pesticides) as well as dinitro aromatic compounds (for pesticides) has been explored, in the present work, to ensure further unambiguous detection.
负离子化学电离是使用具有选定反应物负离子的四极杆离子阱质谱仪进行的，主要从自制的双EI/CI外部离子源注入。因此，根据反应时间提供了选择性离子/分子反应，与传统的高压离子源结合束仪器相比，这对双分子电离机制有更大的控制，在传统仪器中，由于源条件（如温度、压力和推斥极），会发生几种竞争性电离过程。通过选择反应物离子，与几种有机目标化合物特异性地产生离子/分子反应（即电荷交换、质子转移、亲核取代和/或α-β消除）。在本工作中，已探索了含磷和含氮化合物（如作为化学战剂代表的膦酸酯以及作为农药的硫代磷酸酯、二硫代磷酸酯和三嗪）以及二硝基芳族化合物（用于农药）的气相反应性，以确保进一步明确的检测。
