Yamaguchi Kentaro
Chemical Analysis Center, Chiba University, 1-33 Yayoicho, Inage-ku, Chiba 263-8533, Japan.
J Mass Spectrom. 2003 May;38(5):473-90. doi: 10.1002/jms.488.
A direct solution analysis method, cold-spray ionization (CSI) mass spectrometry (MS), a variant of electrospray (ESI) MS operating at low temperature (ca -80 to 10 degrees C), allows the facile and precise characterization of labile organic species, especially those in which non-covalent bonding interactions are prominent. We applied this method to investigations of the solution structures of many labile organic species, including unstable reagents and reaction intermediates, asymmetric catalysts, supramolecules and even primary biomolecules. Remarkable analytical results were obtained for highly ordered supramolecules using the CSI method. Whereas conventional ESI is not applicable to these compounds because of their instability to heat and/or air, CSI affords multiply charged molecular ions with many solvent molecules attached. Investigation of the constitution of Grignard reagents in solution is extremely challenging, but CSI-MS allowed us to identify one of the key structures in THF solution. Recently, this method was adopted for investigations of the solution structures of primary biomolecules such as nucleosides, amino acids, sugars and lipids, revealing singly charged Na(+) adducts of large clusters (chain structures), presumably linked by non-covalent interactions, including hydrogen bonding and/or hydrophobic interactions. The principle of the CSI method and applications of the method to a wide variety of labile organic species and primary biomolecules in solution are described.
一种直接溶液分析方法——冷喷雾电离（CSI）质谱（MS），是电喷雾（ESI）质谱在低温（约 -80至10摄氏度）下运行的一种变体，可轻松、精确地表征不稳定的有机物种，尤其是那些非共价键相互作用显著的物种。我们将此方法应用于许多不稳定有机物种溶液结构的研究，包括不稳定试剂和反应中间体、不对称催化剂、超分子甚至初级生物分子。使用CSI方法对高度有序的超分子获得了显著的分析结果。由于传统ESI不适用于这些对热和/或空气不稳定的化合物，而CSI能提供附着有许多溶剂分子的多电荷分子离子。溶液中格氏试剂组成的研究极具挑战性，但CSI-MS使我们能够鉴定出四氢呋喃（THF）溶液中的一种关键结构。最近，该方法被用于研究核苷、氨基酸、糖和脂质等初级生物分子的溶液结构，揭示了大簇（链结构）的单电荷Na(+)加合物，推测是通过包括氢键和/或疏水相互作用在内的非共价相互作用连接的。本文描述了CSI方法的原理及其在溶液中各种不稳定有机物种和初级生物分子中的应用。
