NMR Phase-Sensitive 2D J-Resolved Spectrum via Strong Coupling Suppression
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Solution Overview
Problem
Conventional NMR 2D J-resolved spectroscopy faces issues with phase distortion and strong coupling spurious peaks, which cannot be effectively suppressed using existing methods, leading to decreased spectral resolution and peak broadening.
Innovation Solution
A method involving a pulse sequence with 180° chirp sweep frequency pulses and a PSYCHE module, combined with weak gradient field pulses, is used to suppress strong coupling spurious peaks, allowing for phase-sensitive data processing and recovery of pure chemical shift information.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If phase-sensitive processing is performed on conventional 2D J-resolved spectrum, then phase distortion is resolved and natural linewidth is maintained, but strong coupling spurious peaks cannot be suppressed
Solution Approach 1:
The patent extracts and eliminates the harmful strong coupling spurious peaks from the NMR spectrum by using a specialized pulse sequence (PSYCHE module) that selectively suppresses these artifacts while preserving the desired phase-sensitive signal information
Solution Approach 2:
The patent changes the pulse sequence parameters by introducing chirp sweep frequency pulses with specific frequency modulation characteristics, replacing conventional rectangular pulses to achieve both phase sensitivity and strong coupling suppression simultaneously
2Reliability
If conventional 2D J-resolved spectrum is displayed in absolute value mode, then phase distortion problem is avoided, but spectral resolution decreases and peak linewidth increases
Solution Approach 1:
The patent applies preliminary phase correction and strong coupling suppression during the data acquisition and processing stages, enabling the spectrum to be displayed in phase-sensitive mode without suffering from phase distortion artifacts
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach effectively suppresses strong coupling spurious peaks, maintaining natural linewidth and improving spectral resolution, enabling more accurate analysis of complex chemical samples.
Implementation Method 1
a 180° forward chirp sweep frequency pulse, a 180° reverse chirp sweep frequency pulse
Implementation Method 2
nuclear magnetic resonance (NMR) spectroscopy detection
Implementation Method 3
a weak gradient field pulse G2 and a weak gradient field pulse G6
Implementation Method 4
provides information on chemical shifts and J-coupling constants in these two dimensions
Implementation Method 5
conventional 2D J-resolved spectrum (2D J spectrum) provides information on chemical shifts and J-coupling constants
Data Source
AI summary
A method for acquiring nuclear magnetic resonance (NMR) phase-sensitive two-dimensional (2D) J-resolved spectrum by suppressing strong coupling spurious peaks, comprising: 1) placing a sample, collecting a conventional one-dimensional (1D) spectrum of the sample, and measuring a time width (pw) of a 90° pulse, wherein the conventional 1D spectrum provides J coupling information and chemical shift information of the sample; and 2) introducing a pulse sequence for suppressing strong coupling, setting parameters of a chirp sweep frequency pulse, a pure shift yielded by chirp excitation (PSYCHE) module, and a J sampling module, and collecting and saving data of a spectrum.