Pulse sequence symmetries in the nuclear magnetic resonance of spinning solids: Application to heteronuclear decoupling

1999 ◽  
Vol 111 (4) ◽  
pp. 1511-1519 ◽  
Author(s):  
Mattias Edén ◽  
Malcolm H. Levitt
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Pulse Sequence ◽  
Nuclear Magnetic

Broadband dipolar recoupling in the nuclear magnetic resonance of rotating solids: A compensated C7 pulse sequence

1998 ◽  
Vol 108 (7) ◽  
pp. 2686-2694 ◽  
Author(s):  
M. Hohwy ◽  
H. J. Jakobsen ◽  
M. Edén ◽  
M. H. Levitt ◽  
N. C. Nielsen
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Pulse Sequence ◽  
Dipolar Recoupling ◽  
Nuclear Magnetic

Guidelines for the representation of pulse sequences for solution-state nuclear magnetic resonance spectrometry (IUPAC Recommendations 2001)

2001 ◽  
Vol 73 (11) ◽  
pp. 1749-1764 ◽  
Author(s):  
Antony N. Davies ◽  
Jörg Lambert ◽  
Robert J. Lancashire ◽  
Peter Lampen ◽  
Woody Conover ◽  
...  
Keyword(s):  
Experimental Data ◽  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Pulse Sequence ◽  
Pulse Sequences ◽  
Resonance Spectroscopy ◽  
Data Content ◽  
Nuclear Magnetic Resonance Spectrometry ◽  
Magnetic Resonance Spectrometry ◽  
Nuclear Magnetic

In drawing up the specifications for a standard for multidimensional nuclear magnetic resonance spectroscopy (NMR) it became clear that the spectroscopic data content needed to be qualified by experimental condition information especially pertaining to the pulse sequences used to obtain the free induced decays or spectra. Failure to include this information not only severely inhibits the ability of subsequent data handling packages to work with the experimental data, but also makes interpretation of the final results virtually impossible.This paper has been produced in collaboration with the NMR spectrometer manufacturers in an attempt to get agreement on a definitive list of the most frequently used pulse sequence programs. The list includes entries where common agreement has been reached as to the acronym to name the experiment and the key instrument independent parameters needed to report concisely. It is not intended to restrict in any way the freedom of manufacturers or users to develop new and novel experimental pulse sequences, but should aid reporting of experimental data where the more common sequences are in use.

scholarly journals Quantitative Analysis of Flavonoids in Glycyrrhiza uralensis Fisch by 1H-qNMR

2021 ◽  
Vol 2021 ◽  
pp. 1-6
Author(s):  
Ping Yu ◽  
Qian Li ◽  
Yanmei Feng ◽  
Yuying Chen ◽  
Sinan Ma ◽  
...  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Pulse Sequence ◽  
Quantitative Characteristic ◽  
Internal Standard ◽  
Proton Nuclear Magnetic Resonance ◽  
Experimental Result ◽  
Resonance Spectroscopy ◽  
Nuclear Magnetic

Objective. To establish a method for simultaneous determination of liquiritin, liquiritigenin, and isoliquiritinin glycyrrhizin using hydrogen nuclear magnetic resonance quantitative technology (1H-qNMR). Methodology. Deuterated dimethyl sulfoxide was used as the solvent, and dichloromethane was used as the internal standard. The probe temperature was 298.0 K, the pulse sequence was Zg30, the number of scans was 16, and relaxation delay (D1) was 10 s. Quantitative characteristic signal peaks were δ 4.891∼4.878 ppm, δ 8.187∼8.172 ppm, and δ 6.790∼6.776 ppm for liquiritin, isoliquiritin, and liquiritigenin, respectively. Results. The experimental result showed that the content of flavonoids in Licorice, from Chifeng, Inner Mongolia, was the highest. Conclusion. In this study, a new method for determination of three flavonoids in Licorice using 1H-qNMR was established. This experimental method has the advantages of accuracy, efficiency, and economy. It lays a foundation for the study on the determination of flavonoids content in licorice by proton nuclear magnetic resonance spectroscopy.

The Wellcome Foundation Lecture, 1984 - Nuclear magnetic resonance imaging in medicine: medical and biological applications and problems

1986 ◽  
Vol 226 (1245) ◽  
pp. 391-419 ◽  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Pulse Sequence ◽  
Clinical Work ◽  
Mental States ◽  
Response To Therapy ◽  
Whole Body ◽  
Proton Density ◽  
Transform Method ◽  
Nuclear Magnetic

From early biological work and the first T 1 nuclear magnetic resonance (n. m. r.) animal image in 1974, whole-body patient images, by using a two-dimensional Fourier transform method were achieved in Aberdeen in 1980 with a 0.04 T vertical resistive magnet. Different pulse sequences produce images dependent by different amounts on proton density, T 1 and T 2 , and for clinical work it is advantageous to use more than one pulse sequence to image pathology. The slow improvement of spatial resolution with increasing standing magnetic field strength is discussed and information on the T 1 and T 2 contrast dependence is reviewed: it suggests that the gains from high fields may be less than believed hitherto. Electrocardiogram gating can be used to produce moving images of the beating heart; blood flow can be imaged and surface radiofrequency coils are used for improved detail. N. m. r. imaging has considerable potential for studying response to therapy; mental states and dementia; tissue generation; discriminating body fat and body fluids. Other nuclei such as 23 Na can be imaged and the potential to image fluorine-labelled pharmaceuticals could be very exciting; n. m. r. contrast agents are now being developed. Images formed T 1 values measured for each pixel are very useful for diagnosis, but the numerical values themselves are less valuable for distinctive pathological identification. With 15 companies manufacturing n. m. r. imagers and over 200 in use in hospitals, the technique is rapidly becoming established in diagnostic clinical practice and some typical uses are presented.

scholarly journals Robust Metabolite Quantification from J-Compensated 2D 1H-13C-HSQC Experiments

Metabolites ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 449
Author(s):  
Alexander Weitzel ◽  
Claudia Samol ◽  
Peter J. Oefner ◽  
Wolfram Gronwald
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Quantum Coherence ◽  
Pulse Sequence ◽  
Latin Square ◽  
Scalar Coupling ◽  
Residual Water ◽  
Physiological Concentration ◽  
Water Signal ◽  
Nuclear Magnetic

The spectral resolution of 2D 1H-13C heteronuclear single quantum coherence (1H-13C-HSQC) nuclear magnetic resonance (NMR) spectra facilitates both metabolite identification and quantification in nuclear magnetic resonance-based metabolomics. However, quantification is complicated by variations in magnetization transfer, which among others originate mainly from scalar coupling differences. Methods that compensate for variation in scalar coupling include the generation of calibration factors for individual signals or the use of additional pulse sequence schemes such as quantitative HSQC (Q-HSQC) that suppress the JCH-dependence by modulating the polarization transfer delays of HSQC or, additionally, employ a pure-shift homodecoupling approach in the 1H dimension, such as Quantitative, Perfected and Pure Shifted HSQC (QUIPU-HSQC). To test the quantitative accuracy of these three methods, employing a 600 MHz NMR spectrometer equipped with a helium cooled cryoprobe, a Latin-square design that covered the physiological concentration ranges of 10 metabolites was used. The results show the suitability of all three methods for the quantification of highly abundant metabolites. However, the substantially increased residual water signal observed in QUIPU-HSQC spectra impeded the quantification of low abundant metabolites located near the residual water signal, thus limiting its utility in high-throughput metabolite fingerprinting studies.

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