Assessing 2D electrophoretic mobility spectroscopy (2D MOSY) for analytical applications

Abstract

Electrophoretic displacement of charged entity phase modulates the spectrum acquired in electrophoretic NMR experiments, and this modulation can be presented via 2D FT as 2D mobility spectroscopy (MOSY) spectra. We compare in various mixed solutions the chemical selectivity provided by 2D MOSY spectra with that provided by 2D diffusion‐ordered spectroscopy (DOSY) spectra and demonstrate, under the conditions explored, a superior performance of the former method. 2D MOSY compares also favourably with closely related LC‐NMR methods. The shape of 2D MOSY spectra in complex mixtures is strongly modulated by the pH of the sample, a feature that has potential for areas such as in drug discovery and metabolomics. Copyright © 2016 The Authors. Magnetic Resonance in Chemistry published by John Wiley & Sons Ltd.

Spectral deconvolution in electrophoretic NMR to investigate the migration of neutral molecules in electrolytes

“…Therefore, the electrophoretic mobility can be analyzed via 2D Fourier transformation in the time domain and the electric field domain E , using a modification of the States–Haberkorn method as applied in various reports . The States method is employed to obtain pure absorption phase spectra and suppress phase twist line shapes .…”

“…In dilute aqueous salt solutions, however, where experimentally observable phase shifts can reach >1,000°, eNMR is established in the investigation of multiple molecular species, which exhibit different phase shifts in the 1 H eNMR spectrum . It was shown that the mobilities can be analyzed via 2D Fourier transformation applying the States–Haberkorn correction yielding a mobility‐ordered spectrum (MOSY) .…”

“…It was shown that the mobilities can be analyzed via 2D Fourier transformation applying the States–Haberkorn correction yielding a mobility‐ordered spectrum (MOSY) . This has been demonstrated as a powerful tool to resolve superimposed 1 H eNMR spectra of, for example, aqueous amino acid mixtures or polyelectrolytes and their counterions by their electrophoretic mobilities …”

A novel approach to study catalytic reactions via electrophoretic NMR on the example of Pd/NHC‐catalyzed Mizoroki–Heck cross‐coupling reaction

“…To enhance the analysis, a 1 H 2D MOSY (Mobility Ordered Spectroscopy) spectrum was obtained using a two‐dimensional Fourier transform in the time domain and in the electric field. [ 22,23 ] It is a 2D NMR spectrum, where the F1 and F2 axes represent the electrophoretic mobility and chemical shift, respectively. Conventional spectrum processing programs cannot process the MOSY spectrum.…”

NMR for Mixture Analysis: Concentration-Ordered Spectroscopy

“…The covariation can be measured statistically and is used to generate pseudo-2D plot of STOCSY . In addition, electrophoretic mobility has also been utilized in NMR (mobility spectroscopy, MOSY) to separate the charged molecules in solution. − However, due to the limited dynamic ranges, the molecules with similar self-diffusion coefficient constants and electronic changes could not be fully resolved by DOSY, MOSY, and STOCSY. Herein, we proposed a novel approach for constructing concentration-ordered NMR spectroscopy (CORDY) for simultaneously separating and quantitating the signals of the components of a mixture.…”