Senko M W, Hendrickson C L, Pasa-Tolić L, Marto J A, White F M, Guan S, Marshall A G
Center for Interdisciplinary Magnetic Resonance, National High Magnetic Field Laboratory, Florida State University, Tallahassee 32310, USA.
Rapid Commun Mass Spectrom. 1996;10(14):1824-8. doi: 10.1002/(SICI)1097-0231(199611)10:14<1824::AID-RCM695>3.0.CO;2-E.
We present the first results from a new electrospray ionization Fourier transform ion cyclotron resonance mass spectrometer operated at a magnetic field of 9.4 T (i.e. > or = 2.4 T higher than for any prior FTICR instrument). The 9.4 T instrument provides substantially improved performance for large molecules (> or = 50% increase in mass resolving power) and complex mixtures (> or = 100% increase in dynamic range) compared to lower-field (< or = 6 T) instruments. The higher magnetic field makes possible larger trapped-ion population without introduction of significant space--charge effects such as spectral peak shift and/or distortion, and coalescence of closely-spaced resonances. For bovine ubiquitin (8.6 kDa) we observe accurate relative isotopic abundances at a signal-to-noise ratio greater than 1000:1, whereas a complete nozzle-skimmer dissociation electrospray ionization (ESI) FTICR mass spectrum of bovine carbonic anhydrase (29 kDa) is achieved from a single scan with a signal-to-noise ratio of more than 250:1. Finally, we are able to obtain mass resolving power, m/delta m > 200,000, routinely for porcine serum albumin (67 kDa). The present performance guides further modifications of the instrument, which should lead to significant further improvements.
我们展示了一台新型电喷雾电离傅里叶变换离子回旋共振质谱仪在9.4 T磁场下运行的首批结果（即比任何先前的傅里叶变换离子回旋共振仪器的磁场高≥2.4 T）。与低场（≤6 T）仪器相比，9.4 T的仪器在大分子分析方面性能显著提升（质量分辨能力提高≥50%），在复杂混合物分析方面也有显著进步（动态范围提高≥100%）。更高的磁场使得捕获更多离子成为可能，且不会引入显著的空间电荷效应，如光谱峰位移和/或畸变，以及紧密间隔共振的合并。对于牛泛素（8.6 kDa），我们在信噪比大于1000:1时观察到了精确的相对同位素丰度，而牛碳酸酐酶（29 kDa）的完整的喷嘴 - 分离器解离电喷雾电离（ESI）傅里叶变换离子回旋共振质谱图通过单次扫描获得，信噪比大于250:1。最后，对于猪血清白蛋白（67 kDa），我们常规能够获得质量分辨能力m/Δm > 200,000。目前的性能为仪器的进一步改进提供了指导，有望带来更大的提升。
