Kaiser Nathan K, Savory Joshua J, Hendrickson Christopher L
Ion Cyclotron Resonance Program National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL, 32310-4005, USA,
J Am Soc Mass Spectrom. 2014 Jun;25(6):943-9. doi: 10.1007/s13361-014-0871-6. Epub 2014 Apr 2.
An auxiliary rf waveform of the same amplitude and phase applied to all the rods of an ion accumulation multipole creates an m/z-dependent axial pseudo potential. Controlled decrease of the auxiliary rf amplitude releases ions from the accumulation multipole sequentially from high to low m/z. The slope of the auxiliary rf voltage ramp is adjusted so that ions of different m/z reach the center of the ICR cell at the same time point, which mitigates the typical time dispersion observed in external source FT-ICR and extends the observable mass range for a single data acquisition by 2- to 3-fold. For complex mixture analysis, twice the number of elemental compositions are assigned when the auxiliary rf ejection is applied compared with the standard gated trapping.
施加到离子累积多极杆所有杆上的具有相同幅度和相位的辅助射频波形会产生与质荷比相关的轴向伪势。辅助射频幅度的受控降低会使离子从累积多极杆中按质荷比从高到低依次释放。调整辅助射频电压斜坡的斜率，以使不同质荷比的离子在同一时间点到达离子回旋共振（ICR）池的中心，这减轻了在外部源傅里叶变换离子回旋共振（FT-ICR）中观察到的典型时间离散，并将单次数据采集的可观测质量范围扩展了2至3倍。对于复杂混合物分析，与标准门控捕获相比，应用辅助射频喷射时分配的元素组成数量是其两倍。
