Doroshenko V M, Cotter R J
Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
Rapid Commun Mass Spectrom. 1996;10(1):65-73. doi: 10.1002/(SICI)1097-0231(19960115)10:1<65::AID-RCM447>3.0.CO;2-M.
The stored waveform inverse Fourier transform (SWIFT) technique is used for broadband excitation of ions in an ion-trap mass spectrometer to perform mass-selective accumulation, isolation, and fragmentation of peptide ions formed by matrix-assisted laser desorption/ionization. Unit mass resolution is achieved for isolation of ions in the range of m/z up to 1300 using a two-step isolation technique with stretched-in-time narrow band SWIFT pulses at the second stage. The effect of 'stretched-in-time' waveforms is similar to that observed previously for mass-scan-rate reduction. The asymmetry phenomenon resulting from the stretched ion-trap electrode geometry is observed during application of normal and time-reversed waveforms and is similar to the asymmetry effects observed for forward and reverse mass scans in the resonance ejection mode. Mass-selective accumulation of ions from multiple laser shots was accomplished using a method described earlier that involves increasing the trapping voltage during ion introduction for more efficient trapping of ions.
存储波形傅里叶逆变换（SWIFT）技术用于离子阱质谱仪中离子的宽带激发，以实现对基质辅助激光解吸/电离形成的肽离子进行质量选择性积累、分离和碎裂。使用两步分离技术，在第二阶段采用时间拉伸窄带SWIFT脉冲，可实现m/z高达1300范围内离子的单位质量分辨率分离。“时间拉伸”波形的效果与之前观察到的质量扫描速率降低的效果类似。在施加正向和时间反转波形期间，观察到由拉伸离子阱电极几何形状导致的不对称现象，这与共振喷射模式下正向和反向质量扫描中观察到的不对称效应类似。使用先前描述的一种方法完成了来自多次激光照射的离子的质量选择性积累，该方法涉及在离子引入期间增加捕获电压，以更有效地捕获离子。
