Kendrick mass defect spectrum: A compact visual analysis for ultrahigh-resolution broadband mass spectra
Kendrick mass defect spectrum: A compact visual analysis for ultrahigh-resolution broadband mass spectra
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DOI：
10.1021/ac010560w
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发表时间：
2001-10-01
影响因子：
7.4
通讯作者：
Qian, KN
中科院分区：
文献类型：
--
作者：
Hughey, CA;Hendrickson, CL;Qian, KN
在目前可实现的傅里叶变换离子回旋共振宽带质谱分辨能力（对于200 < m/z < 1000，m/m Δ m（50%）> 350 000）下，有必要将常规质谱展开到类似于200 μ m，以便提供最接近分辨的峰的视觉分辨率。幸运的是，在典型的质谱中存在间隔为1 Da的天然间隙，因为几乎没有常见的元素组成产生这些值的质量。因此，有可能将宽带质谱分成1-Da片段，将每个片段旋转90度，根据其质量亏损缩放每个片段（即，精确质量和标称质量之间的差异），然后压缩段之间的间距以产生紧凑的显示。对于烃系统，从IUPAC质量到“Kendrick”质量（即，将每个质量乘以14.00000/14.01565）通过将峰值图案直线化进一步简化了显示。所得到的显示不仅保留了“粗略”间距（例如，奇数和偶数质量之间类似于1 Da，对应于偶数对奇数个氮或C-12（c）对C-12（c-1），C-13（1）相同分子的元素组成;类似于2-Da分离，对应于双键或环;类似于14 Da分离，对应于一个CH 2基团），而且“精细结构”（即，不同元素组成的不同质量缺陷）。该方法说明了实验电喷雾电离FTICR超高分辨率质谱的石油原油。几千种元素组成可以在一页二维显示中直观地分辨出来，以及各种化合物族--类NnOoSs）、类型（CcH 2c +ZNnOoSs中的Z）。
At currently achievable Fourier transform ion cyclotron resonance broadband mass spectrometry resolving power (m/m Deltam(50%) > 350 000 for 200 < m/z < 1000), it would be necessary to spread out a conventional mass spectrum over similar to 200 m in order to provide visual resolution of the most closely resolved peaks. Fortunately, there are natural gaps in a typical mass spectrum, spaced 1 Da apart, because virtually no commonly encountered elemental compositions yield masses at those values. Thus, it is possible to break a broadband mass spectrum into 1-Da segments, rotate each segment by 90 degrees, scale each segment according to its mass defect (i.e., difference between exact and nominal mass), and then compress the spacing between the segments to yield a compact display. For hydrocarbon systems, conversion from IUPAC mass to "Kendrick" mass (i.e., multiplying each mass by 14.00000/14.01565) further simplifies the display by rectilinearizing the peak patterns. The resulting display preserves not only the "coarse" spacings (e.g., similar to1 Da between odd and even masses, corresponding to either even vs odd number of nitrogens or C-12(c) vs C-12(c-1), C-13(1) elemental compositions of the same molecule; similar to2-Da separations, corresponding to a double bond or ring; similar to 14 Da separations, corresponding to one CH2 group) but also the "fine structure" (i.e., different mass defects for different elemental compositions) across each I-Da segment. The method is illustrated for experimental electrospray ionization FTICR ultrahigh-resolution mass spectra of a petroleum crude oil. Several thousand elemental compositions may be resolved visually in a single one-page two-dimensional display, and various compound families-class NnOoSs), type (Z in CcH2c+ZNnOoSs).