Mass Spectrometry on the Chromatographic Time Scale: Realistic Expectations
Mass Spectrometry on the Chromatographic Time Scale: Realistic Expectations
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色谱时间尺度上的质谱分析：现实的期望
DOI：
10.1021/ac00260a766
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发表时间：
1983
影响因子：
7.4
通讯作者：
J. Watson
中科院分区：
文献类型：
--
作者：
J. Holland;C. Enke;J. Allison;J. Stults;J. Pinkston;Bruce Hewitt Newcome;J. Watson
对于复杂混合物的分析，气相色谱-质谱仪(GC/MS)被认为是一种非常有价值的工具。将色层分离与可高度选择性的二维(质量、强度)检测器相结合，为许多分析问题提供了解决方案，从监测废水中的污染物(1)到测量体液中的代谢物水平(2)。由于需要更好的分离，对色谱分辨率的持续改进可能会导致样品在离子源中的停留时间和质谱扫描时间之间的时间关系紧张。在许多情况下，质谱仪的扫描速度被推到了极限。为了评估从日益狭窄的色谱峰中获得足够的质量谱数据的可能性，有必要对现代质谱计的扫描能力进行检查。随着GC/MS联用技术的成熟，有两个令人信服的理由需要更快地扫描质谱仪；一个与MS有关，另一个与GC有关。第一种方法是在获取光谱的过程中最小化离子源中样品浓度的变化，以便最小化给定谱的相对峰强度的失真。从典型的填充柱进样，可以在1-2个S范围内获得完整的光谱，而对于毛细管柱气相色谱/质谱仪，在0.2-0.5个S范围内收集光谱可以将同样的问题减少到最低限度。对于那些希望从连续记录的质谱图(3-6)重建色谱图的工人来说，高重复率是重要的。光谱采集的频率越高，可用于定义色谱图的点数就越多。选择离子监测是另一种方法，它为每个色谱峰提供大量的点，但这种专门的技术只适用于对几个预先选择的质量上的离子电流感兴趣的分析。图1中的例子说明了扫描速度对GC/MS应用中准确表示色谱分辨率的质量数据库容量的关键依赖关系。请注意，图1中的GC峰大约有3-4个S宽。(A)中的质谱图代表一对色谱线，但第二秒的表观大小
For the analysis of complex mixtures, combined gas chromatography-mass spectrometry (GC/MS) is recognized as an invaluable tool. The cou-pling of chromatographic separation with a two-dimensional (mass, intensity) detector that can be highly selec-tive provides the solution to many an-alytical problems ranging from moni-toring pollutants in wastewater (1) to measuring metabolite levels in body fluids (2). Continuing improvements in chromatographic resolving power, necessitated by the demand forbetter separations, can lead to a strain in the temporal relationship between residence time of the sample in the ion source and mass spectral scan time. In many cases, mass spectrometer scan-ning rates are being pushed to their limit. An examination of the scanning capabilities of modern mass spectrom-eters is necessary to assess the feasi-bility of obtaining adequate mass spectral data from increasingly narrow chromatographic peaks. As thetechnique of combined GC/MS has matured, there have been two compelling reasons to scan the mass spectrometer more quickly; one relates to MS, the other to GC. The first is to minimize changes in sample concentration in the ion source during the time a spectrum is acquired in order to minimize distortion of rela-tive peak intensities for a given spectrum. With sample introduction from a typical packed column this can be accomplished by obtaining the com-plete spectrum in 1-2 s. For capillary column GC/MS t he same problem can be minimized by collecting the spectrum in 0.2-0.5 s. The second reason for requiring high scan rates in GC/MS is to increase the frequency at which complete mass spectra are col-lected. High repetition rates are im-portant for those workers who wish to reconstruct the chromatogram from consecutively recorded mass spectra (3-6). The greater the frequency of spectrum acquisition, the greater the number of points available to define the chromatographic profile. Selected ion monitoring, an alternative ap-proach, provides a large number of points per chromatographic peak, but this specialized technique is useful only for analyses inwhich the ion cur-rents at a few preselected masses are of interest.The example in Figure 1 illustrates the critical dependence of scan rate on the capacity of a mass spectral data base to accurately represent chromatographic resolution in GC/MS ap-plications. Note that the GC peak in Figure 1 is approximately 3-4 s wide. The mass chromatogram in (a) represents a chromatographic doublet, but the apparent magnitude of thesecond
通过气相色谱质谱数据系统对尿类固醇进行自动代谢谱分析。
DOI：
10.1002/bms.1200100309
发表时间：
1983
期刊：
Biomedical mass spectrometry
影响因子：
--
作者：
Vrbanac,JJ;Sweeley,CC;Pinkston,JD
通讯作者：
Pinkston,JD
DOI：
10.1002/bms.1200080915
发表时间：
1981
期刊：
Biomedical mass spectrometry
影响因子：
--
作者：
Sweeley,CC;Vrbanac,J;Pinkston,D;Issachar,D
通讯作者：
Issachar,D