Kolakowski Beata M, Grossert J Stuart, Ramaley Louis
Department of Chemistry, Dalhousie University, Halifax, Nova Scotia, Canada.
J Am Soc Mass Spectrom. 2004 Mar;15(3):301-10. doi: 10.1016/j.jasms.2003.10.015.
The response of atmospheric pressure chemical ionization (APCI) mass spectrometry to selected polycyclic aromatic compounds (PACs) was examined in a Micromass Quattro atmospheric pressure ion source as a function of both solvents and source gases. Typical PACs found in petroleum samples were represented by mixtures of naphthalene, fluorene, phenanthrene, pyrene, fluoranthene, chrysene, triphenylene, perylene, carbazole, dibenzothiophene, and 9-phenanthrol. A large range of different gases in the APCI source was studied, with emphasis on nitrogen, air, and carbon dioxide. Solvents used included water-acetonitrile, acetonitrile, dichloromethane, and hexanes. The signal responses were dependent on both the gases and solvents used, as was the ionization mechanism, as indicated by the degree of protonation with respect to the level of charge exchange. The combination of carbon dioxide in the nebulizer gas stream with nitrogen in the other streams gave a three- to fourfold better sensitivity than using nitrogen alone for both test mixtures and for complex samples.
在Micromass Quattro大气压离子源中，研究了大气压化学电离（APCI）质谱对选定多环芳烃化合物（PACs）的响应，该响应是溶剂和源气体两者的函数。石油样品中发现的典型PACs由萘、芴、菲、芘、荧蒽、 Chrysene、三亚苯、苝、咔唑、二苯并噻吩和9-菲酚的混合物表示。研究了APCI源中大量不同的气体，重点是氮气、空气和二氧化碳。使用的溶剂包括水-乙腈、乙腈、二氯甲烷和己烷。信号响应取决于所使用的气体和溶剂，电离机制也是如此，如质子化程度相对于电荷交换水平所示。雾化器气流中的二氧化碳与其他气流中的氮气相结合，对于测试混合物和复杂样品，其灵敏度比单独使用氮气提高了三到四倍。
