NMR Detector Assembly Using Orthogonal RF Fields for Enantiomer Discrimination
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for discriminating enantiomers of chiral substances in NMR spectroscopy require chiral derivatizing agents or solvating agents, leading to peak overlap and additional purification steps, and are limited by the need for equal concentrations or sufficient molar extinction coefficients.
Innovation Solution
An NMR detector assembly using stripline-based RF magnetic and electric fields, applied perpendicular to the static magnetic field, induces a chiral perturbation that differentiates enantiomers through their unique spin dynamics without the need for chiral agents, allowing discrimination in both liquid and solid samples.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If chiral derivatizing agents or solvating agents are used for enantiomer discrimination by NMR, then enantiomers can be discriminated, but peak overlap occurs and additional purification steps are required
Solution Approach 1:
The patent extracts and eliminates the need for chiral derivatizing agents or solvating agents from the NMR detection system. By using an achiral environment with standard NMR techniques, the method removes the source of peak overlap and purification complications while maintaining enantiomer discrimination capability through detection of enantiomerically induced changes in net signal phase
Solution Approach 2:
The patent introduces an intermediary mechanism - the use of a chiral auxiliary field or chiral interaction during the NMR detection process that mediates between the achiral NMR environment and the chiral enantiomers, enabling discrimination without requiring chiral chemical agents that would cause peak overlap
2Ease of operation
If conventional NMR methods are used for enantiomer discrimination, then the technique is simple, but it cannot discriminate enantiomers directly without conversion to diastereomers
Solution Approach 1:
The patent changes the detection parameter in NMR from conventional chemical shift differences to enantiomerically induced changes in net signal phase. This parameter change allows direct enantiomer discrimination while maintaining the simplicity of standard NMR techniques, as the phase changes can be detected using conventional NMR instrumentation and data processing methods
3Measurement precision
If optical rotation or circular dichroism is used for enantiomer discrimination, then enantiomers can be distinguished, but the techniques are limited by equal concentration requirements or sufficient molar extinction coefficients
Solution Approach 1:
The patent creates a universal NMR-based method that can discriminate enantiomers under diverse sample conditions without being restricted by concentration requirements or molar extinction coefficients. The technique works with standard NMR instrumentation and can analyze various types of samples including those with low concentration or insufficient chromophoric properties, making it broadly applicable across different chemical systems
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
Enables enantiomer discrimination in NMR spectroscopy without chiral agents, providing accurate and efficient differentiation of enantiomers based on net signal phase changes, even in racemic mixtures, and distinguishing racemic mixtures from non-chiral substances.
Implementation Method 1
a first set of striplines adapted to create a time-dependent RF magnetic field B1(t) for applying an RF magnetic field pulse... a second set of striplines adapted to create a time-dependent RF electric field E2(t)... located at the intersection of the RF magnetic field B1 and the RF electric field E2
Implementation Method 2
attempts have been made to exploit nuclear magnetic resonance (NMR) for discriminating the enantiomers... since NMR spectroscopy is considered incapable of discriminating the two mirror images as the nuclear shielding tensor responsible for chemical shifts due to the Zeeman effect is even under parity
Data Source
Figure 1
Figure 2
Figure 3a~3d
AI summary
The present invention relates to an NMR detector assembly for discriminating the enantiomers of a chiral substance contained in a sample, the NMR detector assembly being adapted to be inserted in an NMR spectrometer and comprising: a first set of striplines adapted to create a time-dependent RF magnetic field B1(t) for applying an RF magnetic field pulse along the direction of the RF magnetic field B1 such that the net magnetisation of the sample is flipped from its initial position along the direction of the static magnetic field B0 of the NMR spectrometer by an angle θ ≠ (k - 1/2) × π, k being a nonzero positive integer; a second set of striplines adapted to create a time-dependent RF electric field E2(t) perpendicular to the RF magnetic field B1 for applying an RF electric field pulse along the direction of the RF electric field E2 simultaneously with the RF magnetic field pulse along the direction of the RF magnetic field B1; and a sample probing region located at the intersection of the RF magnetic field B1 and the RF electric field E2, wherein the NMR detector assembly is adapted to be inserted in the NMR spectrometer in such a way that each of the RF magnetic field B1 and the RF electric field E2 are perpendicular to the static magnetic field B0 of the NMR spectrometer in the sample probing region. Further, the present invention relates to a corresponding method and to a corresponding computer-program product for discriminating the enantiomers of a chiral substance contained in a sample, which employ said NMR detector assembly.