High-resolution multiple-ion simultaneous monitoring by means of multiple-foldover Fourier transform ion cyclotron resonance mass spectrometry.
High-resolution multiple-ion simultaneous monitoring by means of multiple-foldover Fourier transform ion cyclotron resonance mass spectrometry.
复制标题
通过多重折叠傅里叶变换离子回旋共振质谱进行高分辨率多离子同时监测。
DOI：
10.1021/ac00155a014
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发表时间：
1988
影响因子：
7.4
通讯作者：
Marshall,AG
中科院分区：
文献类型：
--
作者：
Wang,M;Marshall,AG
在傅里叶变换离子回旋共振（FT/ICR）质谱中，超高的质量分辨率需要较长的时域数据采集周期，而宽质量范围的覆盖需要快速的时域采样速率。因此，高分辨宽范围FT/ICR质谱需要很大的数据集（> 1 Mword）。然而，当真实的离子质荷比（m/z）值是已知的，但不同m/z的离子的相对丰度是未知的（如在多离子监测中），那么在远低于奈奎斯特极限的频率下的时域采样可以将来自广泛分离的m/z值的离子的ICR信号”折叠”成单个窄带（因此具有高分辨率）光谱。例如，我们通过以导致超过1000倍的速率直接采样，以足以分辨CO（来自N2）和N2 O（来自CO2）而没有外差的分辨率产生了呼吸气体（H2O、N2、O2、CO2、N2 O）的电子电离混合物的单个质谱。在所有形式的离散光谱法中，数字分辨率受到数据集最大大小的限制（例如，1 Kword到1 Mword左右）。因此，即使有高模拟分辨率的实验光谱，通常也只能通过缩小光谱频率范围来接近模拟分辨率，以便最终的离散光谱为每个模拟线宽提供几个数据点（在半峰高处测量）。因此，人们通常必须选择导致窄范围高分辨率光谱或宽范围低分辨率光谱的条件。例如，在傅里叶变换离子回旋加速器中，
In Fourier transform Ion cyclotron resonance(FT/ICR) mass spectrometry, uttrahlgh mass resolution requires a long time-domain data acquisition period, whereas coverage of a wide mass range requires a rapid time-domain sampling rate. A hlgh-resolutlon wide-range FT/ICR mass spectrum thus re-quires a very large data set (> 1 Mword). However, when the true ionic mass-to-charge (m/z) values are known but the relative abundances ofIons of different m/z are not (as In multlple-lon monitoring), then time-domain sampling at a frequency well below the Nyquist limit can" fold over" the ICR signals from Ions of widely separated m/z valuesInto a single narrow-band (and thus hlgh-resolutlon) spectrum. For exam-ple, we have produced a single mass spectrum of an electron-ionized mixture of respiratory gases (H20, N2, 02, C02, N20) at a resolution sufficient to resolve CO (from N2) and N20 (from C02) without heterodyning, by direct sampling at a rate leading to more than 1000 foldovers. Other applications are discussed.In all forms of discrete spectrometry, digital resolution is limited by the maximum size of the data set (eg, 1 Kword to 1 Mword or so). Thus, even when an experimental spec-trum is available athigh analog resolution, that analog res-olution can generally be approachedonly by narrowing the spectral frequency range so that the final discrete spectrum provides several data points per analog line width (measured at, say half-maximum peak height). One must therefore usually choose conditions which lead either to a narrow-range high-resolution spectrum or to a wide-range low-resolution spectrum. For example, in Fourier transform ion cyclotron