Related Experiment Video
Updated: Jun 7, 2025
13:16
Pure Shift Nuclear Magnetic Resonance: a New Tool for Plant Metabolomics
Published on: July 31, 2021
1.8K
Deep learning enabled ultra-high quality NMR chemical shift resolved spectra
Zhengxian Yang1, Weigang Cai1, Wen Zhu1
1Department of Electronic Science, Fujian Provincial Key Laboratory of Plasma and Magnetic Resonance, State Key Laboratory of Physical Chemistry of Solid Surfaces, Xiamen University Xiamen Fujian 361005 China linyq@xmu.edu.cn.
Chemical Science
|November 21, 2024
Summary
A new neural network, spin echo to obtain chemical shifts network (SE2CSNet), enhances nuclear magnetic resonance (NMR) spectroscopy. It achieves high-resolution, sensitive chemical shift detection, even for overlapping or weak signals in noisy data.
Area of Science:
- Nuclear Magnetic Resonance (NMR) Spectroscopy
- Computational Chemistry
- Signal Processing
Background:
- High-quality chemical shift resolved spectra are crucial for detailed molecular analysis in NMR.
- Existing methods often struggle with overlapping signals, low signal-to-noise ratios, and artifacts.
Purpose of the Study:
- To develop a novel neural network for processing NMR spin echo data.
- To improve the resolution, sensitivity, and accuracy of chemical shift detection.
Main Methods:
- A neural network, SE2CSNet, was designed to analyze NMR spin echo spectra.
- The network detects chemical shifts by identifying phase changes within the spectral data.
- The method was evaluated on its ability to handle complex spectral features and noise.
Main Results:
- SE2CSNet accurately identifies chemical shift positions, even with overlapping signals.
- The network effectively processes low signal-to-noise ratio (S/N) samples, recovering weak signals.
- Artifacts such as strong coupling and chunking were avoided, leading to ultra-high quality spectra.
Conclusions:
- SE2CSNet offers a powerful new approach for obtaining high-quality chemical shift resolved NMR spectra.
- The methodology shows potential for broad applicability across various scientific disciplines requiring detailed NMR analysis.
Related Concept Videos
01:15NMR Spectroscopy: Chemical Shift Overview
1.4K
The position of the absorption signal of a sample is reported relative to the position of the signal of tetramethylsilane (TMS), which is added as an internal reference while recording spectra. The difference between the absorption frequencies of the sample and TMS (in Hz) is divided by the spectrometer operating frequency (in MHz) to obtain a dimensionless quantity called the chemical shift. It is reported on the δ (delta) scale and expressed in parts per million.
For instance, the proton...
For instance, the proton...
1.4K
01:02¹H NMR: Interpreting Distorted and Overlapping Signals
1.0K
Spin systems where the difference in chemical shifts of the coupled nuclei is greater than ten times J are called first-order spin systems. These nuclei are weakly coupled, and their chemical shifts and coupling constant can generally be estimated from the well-separated signals in the spectrum.
As Δν decreases and the signals move closer, the doublets appear increasingly distorted. The intensities of the inner lines increase at the cost of those of the outer lines as the signals are...
As Δν decreases and the signals move closer, the doublets appear increasingly distorted. The intensities of the inner lines increase at the cost of those of the outer lines as the signals are...
1.0K
01:14NMR Spectrometers: Resolution and Error Correction
672
When magnetic nuclei in a sample achieve resonance and undergo relaxation, the signal detected in NMR is an approximately exponential free induction decay. Fourier transform of an exponential decay yields a Lorentzian peak in the frequency domain. Lorentzian peaks in an NMR spectrum are defined by their amplitude, full width at half maximum, and position, where the peak width is governed by the spin-spin relaxation time alone. In real experiments, however, the applied magnetic field is rendered...
672
01:20¹³C NMR: Distortionless Enhancement by Polarization Transfer (DEPT)
1.0K
When proton-coupled carbon-13 spectra are simplified by a broadband proton decoupling technique, structural information about the coupled protons is lost. Distortionless enhancement by polarization transfer (DEPT) is a technique that provides information on the number of hydrogens attached to each carbon in a molecule. While the DEPT experiment utilizes complex pulse sequences, the pulse delay and flip angle are specifically manipulated. The resulting signals have different phases depending on...
1.0K
01:19NMR Spectroscopy Of Amines
8.5K
In proton NMR spectroscopy, primary amines and secondary amines showcase their N–H protons as a broad signal in the chemical shift range between δ 0.5 and 5 ppm. The exact position in this range depends on several factors, including sample concentration, hydrogen bonding, and the type of solvent used. Since amine protons undergo fast proton exchange in solution, the protons are labile and therefore do not participate in any splitting with adjacent protons. Thus, the observed peak is...
8.5K
01:12Two-Dimensional (2D) NMR: Overview
623
The 1D NMR spectrum of large and complex molecules like natural products has complicated splitting patterns and overlapping signals, which can be easily interpreted using 2-dimensional (2D) NMR. Unlike 1D NMR, 2D NMR has two frequency axes that provide the coupling information between the nucleus A and nucleus B in a molecule. The process from which 2D spectra are obtained has four steps.
The first step is the preparation period, during which nucleus A is excited with a radiofrequency pulse....
The first step is the preparation period, during which nucleus A is excited with a radiofrequency pulse....
623