Murrell J, Despeyroux D, Lammert S A, Stephenson J L, Goeringer D E
Dstl, Detection Department, Porton Down, Salisbury, Wiltshire, United Kingdom.
J Am Soc Mass Spectrom. 2003 Jul;14(7):785-9. doi: 10.1016/S1044-0305(03)00326-X.
Collision-induced dissociation (CID) in a quadrupole ion trap mass spectrometer is usually performed by applying a small amplitude excitation voltage at the same secular frequency as the ion of interest. Here we disclose studies examining the use of large amplitude voltage excitations (applied for short periods of time) to cause fragmentation of the ions of interest. This process has been examined using leucine enkephalin as the model compound and the motion of the ions within the ion trap simulated using ITSIM. The resulting fragmentation information obtained is identical with that observed by conventional resonance excitation CID. "Fast excitation" CID deposits (as determined by the intensity ratio of the a(4)/b(4) ion of leucine enkephalin) approximately the same amount of internal energy into an ion as conventional resonance excitation CID where the excitation signal is applied for much longer periods of time. The major difference between the two excitation techniques is the higher rate of excitation (gain in kinetic energy) between successive collisions with helium atoms with "fast excitation" CID as opposed to the conventional resonance excitation CID. With conventional resonance excitation CID ions fragment while the excitation voltage is still being applied whereas for "fast excitation" CID a higher proportion of the ions fragment in the ion cooling time following the excitation pulse. The fragmentation of the (M + 17H)(17+) of horse heart myoglobin is also shown to illustrate the application of "fast excitation" CID to proteins.
在四极杆离子阱质谱仪中，碰撞诱导解离（CID）通常是通过施加与目标离子相同回旋频率的小幅度激发电压来实现的。在此，我们披露了一些研究，这些研究考察了使用大幅度电压激发（短时间施加）来促使目标离子碎裂的情况。以亮氨酸脑啡肽作为模型化合物对该过程进行了研究，并使用ITSIM模拟了离子在离子阱中的运动。所获得的最终碎裂信息与通过传统共振激发CID所观察到的信息相同。“快速激发”CID（由亮氨酸脑啡肽的a(4)/b(4)离子强度比确定）向离子中注入的内能与传统共振激发CID大致相同，而传统共振激发CID的激发信号施加时间要长得多。这两种激发技术的主要区别在于，与传统共振激发CID相比，“快速激发”CID在与氦原子连续碰撞之间具有更高的激发速率（动能增加）。在传统共振激发CID中，离子在仍施加激发电压时就会碎裂，而对于“快速激发”CID，更高比例的离子在激发脉冲后的离子冷却时间内碎裂。还展示了马心肌红蛋白的(M + 17H)(17+)的碎裂情况，以说明“快速激发”CID在蛋白质分析中的应用。
