NMR as a Chromatography Detector
NMR as a Chromatography Detector
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NMR 作为色谱检测器
DOI：
10.1002/9783527654703.ch52
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发表时间：
2014
影响因子：
2
通讯作者：
K. Albert
中科院分区：
文献类型：
--
作者：
K. Albert
为了满足快速有效地鉴定分析物的需要，色谱分离技术与光谱或光谱检测方法的联用在未来十年的科学和工业中对于结构解析的目的将变得越来越重要。目前使用最多的是高效液相色谱HPLC与质谱（MS）的直接耦合。新开发的离子化技术，如电喷雾离子化（ESI）和大气压化学离子化（APCI），在与HPLC联用时，可提供非常有价值的信息。尽管LC-MS联用在许多应用中显示出优势，但NMR光谱被认为是用于明确未知化合物结构的最强大的光谱方法之一。特别地，NMR光谱学具有区分结构异构体、构象异构体和光学异构体的能力。由于NMR探针设计的不断改进和固相萃取（SPE）的应用，灵敏度可以大幅提高，因此可以在所有现有的色谱分离技术（包括毛细管规模分离和NMR光谱检测）之间进行在线耦合实验。分离技术（如HPLC，毛细管高效液相色谱（capHPLC），凝胶渗透色谱法（GPC）、超临界流体色谱法（SFC）、毛细管气相色谱法（GC）、毛细管电泳法（CE）和毛细管电色谱法（CEC）结合NMR光谱证明有利于氧化和UV敏感化合物的结构解析。在闭环分离- NMR检测系统中，分离的化合物的降解或异构化在很大程度上受到阻碍。使用少量的样品，通过SPE在检测池中获得更高浓度的分析物，从而为1D和2D NMR光谱提供合理的NMR采集时间。因此，通过在液体和气体状态下采用纳升尺度的停流2D NMR光谱，可以对未知色谱峰进行明确的结构归属。来自不同应用领域的实例将展示将分离技术与NMR相结合的高应用能力，采用定制的固定相。正在进行的开发涉及在线13 C NMR检测的开发。首先，将报告令人鼓舞的结果。
To fulfill the need for fast and efficient identification of analytes, hyphenation of chromatographic separation techniques with spectroscopic or spectrometric detection methods will be of increasing importance for structure elucidation purposes in science and industry in the next decade. Mostly used these days is the direct coupling of high‐performance liquid chromatography HPLC to mass spectrometry (MS). Newly developed ionization techniques such as electrospray ionization (ESI) and atmospheric pressure chemical ionization (APCI) yield extremely valuable information when hyphenated to HPLC. Despite the advantages of LC–MS coupling shown in numerous applications, NMR spectroscopy is considered to be one of the most powerful spectroscopic methods for the unambiguous structural elucidation of unknown compounds. In particular, NMR spectroscopy has the capability to distinguish between structural, conformational, and optical isomers. Owing to continuous improvements in the design of NMR probes and the employment of solid phase extraction (SPE), the sensitivity could drastically be increased so that online coupling experiments between all existing chromatographic separation techniques including capillary scale separations and NMR spectroscopic detection can be performed.The hyphenation of separation techniques such as HPLC, capillary high‐performance liquid chromatography (capHPLC), gel permeation chromatography (GPC), supercritical fluid chromatography (SFC), capillary gas chromatography (GC), capillary electrophoresis (CE), and capillary electrochromatography (CEC) with NMR spectroscopy proves advantageous for the structure elucidation of oxidation and UV‐sensitive compounds. In the closed‐loop separation – NMR detection system, degradation, or isomerization of separated compounds is largely hindered. With small amounts of sample, higher concentrations of analyte in the detection cell are obtained by SPE, leading to reasonable NMR acquisition times for 1D and 2D NMR spectra. Thus, unequivocal structural assignment of unknown chromatographic peaks is possible by employing stopped‐flow 2D NMR spectroscopy in the nanoliter scale in the liquid and gaseous states. Practical examples from different application fields will demonstrate the high application power of combining separation techniques together with NMR, employing tailored stationary phases.An ongoing development deals with the development of online13C NMR detection. First, the encouraging results will be reported.
影响因子：
7.4
作者：
Olson,DL;Lacey,ME;Sweedler,JV
通讯作者：
Sweedler,JV
使用在线 NMR 光谱深入了解 cITP 过程。
影响因子：
7.4
作者：
Wolters,AndrewM;Jayawickrama,DimuthuA;Larive,CynthiaK;Sweedler,JonathanV
通讯作者：
Sweedler,JonathanV