Chemistry Department, Baker Laboratory, Cornell University, 14853-1301, Ithaca, NY, USA.
J Am Soc Mass Spectrom. 1990 Nov;1(6):427-30. doi: 10.1016/1044-0305(90)85025-H.
For ions formed by plasma desorption (PD) in a Fourier-transform mass spectrometer, high resolution measurements are demonstrated, such as 65,000 (FWHH) for the protonated molecularion of gramicidin S (MW 1140.7). Resolution is substantially improved by delaying measurements until a significant ion concentration has built up in the cell, and by collisionally deactivating the orbital kinetic energy of the ions. This also makes the ions available for subsequent dissociation steps, so that tandem mass spectrometry can be demonstrated for PD ions. With this for larger ions, collisionally activated dissociation (CAD) is effected with > 85% efficiency. The CAD spectra of (M + Na)(+) and of fragment ions from the PD of gramicidin S provide structurally useful information.
对于在傅里叶变换质谱仪中由等离子体解吸 (PD) 形成的离子，可进行高分辨率测量，例如对短杆菌肽 S（MW 1140.7）的质子化分子离子进行 65000（半峰全宽）的测量。通过延迟测量直到细胞中积累了显著的离子浓度，以及通过碰撞使离子的轨道动能失活，分辨率得到了极大的提高。这也使得离子可用于后续的解离步骤，从而可以对 PD 离子进行串联质谱分析。对于更大的离子，通过碰撞激活解离 (CAD) 可实现超过 85%的效率。(M + Na)(+)的 CAD 光谱以及短杆菌肽 S PD 产生的碎片离子的 CAD 光谱提供了有用的结构信息。
