Graduate School of Science and Engineering , Doshisha University , Kyotanabe , Kyoto 610-0321 , Japan.
Koichi Tanaka Mass Spectrometry Research Laboratory , Shimadzu Corporation , Nakagyo-ku , Kyoto 604-8511 , Japan.
Anal Chem. 2018 Jun 19;90(12):7239-7245. doi: 10.1021/acs.analchem.8b00344. Epub 2018 Jun 5.
A thermal cracking cell that served as the atomic hydrogen source for hydrogen attachment/abstraction dissociation (HAD) analysis has an intrinsic problem to produce a beam of atoms reactive against heated tungsten capillary. A plasma excited by 2.45 GHz microwave discharge can deliver reactive species to a quadrupole ion trap confining analyte ions without excessive heating of the radical source components. The radical (H) production performance of the developed source was evaluated by optical emission spectroscopy and H attachment reaction to fullerene ions. The source exhibited the H attachment rate as high as a thermal cracking source forming H in the high temperature tungsten capillary to induce fragmentation processes preserving post-translational modifications. Water vapor was introduced to the source to confirm the stability to generate oxygen containing radicals, which were found present in the water vapor plasma together with atomic hydrogen. Injection of radicals from a water vapor plasma successfully dissociated peptide ions to c-/z- and a-/x-type ions as the case of HAD induced by a thermal cracking cell.
作为原子氢供体用于氢加成/消除解离（HAD）分析的热裂化池存在一个固有问题，即难以产生一束可与加热的钨毛细管反应的原子束。由 2.45GHz 微波放电激发的等离子体可将反应性物质输送到四极离子阱中，限制分析物离子，而不会过度加热自由基源组件。通过光发射光谱和富勒烯离子的 H 加成反应评估了所开发的源的自由基（H）生成性能。该源表现出的 H 加成速率与在高温钨毛细管中形成 H 的热裂化源一样高，这会导致碎裂过程，从而保留翻译后修饰。将水蒸气引入到该源中，以确认其生成含氧自由基的稳定性，在水蒸气等离子体中与原子氢一起发现了含氧自由基。从水蒸气等离子体中注入自由基成功地将肽离子解离为 c-/z- 和 a-/x- 型离子，这与热裂化池诱导的 HAD 情况相同。
