Ultrafast 2D NMR for the analysis of complex mixtures

In‐line Multidimensional NMR Monitoring of Photochemical Flow Reactions

“…Another less explored approach would be to combine UF experiments and non‐linear sampling [28] . Each 2D COSY spectrum was acquired here with 4 interleaved scans to cover the required spectral width, [27] and either 1 or 2 averages, resulting in a total experiment duration of 35 or 70 s or less. This is more than 10 times faster than the corresponding conventional experiment.…”

“…2D NMR experiments are useful to address overlap issues and provide additional structural information, but the duration of conventional 2D experiments is hardly compatible with in‐line analysis, which ideally requires short analysis durations for high throughput, and efficient process control and automation. Ultrafast (UF) 2D NMR makes it possible to accelerate experiments by one order of magnitude or more, [26] and is a powerful tool for reaction monitoring [27] . Notably, UF NMR methods can provide broadband 2D spectra in less than 1 minute at mM concentrations at high field, and this is comparable to the duration of a 1D experiment [27] .…”

“…Ultrafast (UF) 2D NMR makes it possible to accelerate experiments by one order of magnitude or more, [26] and is a powerful tool for reaction monitoring [27] . Notably, UF NMR methods can provide broadband 2D spectra in less than 1 minute at mM concentrations at high field, and this is comparable to the duration of a 1D experiment [27] . UF 2D NMR has never been used, however, for the in‐line analysis of a flow reaction.…”

NMR methods for the analysis of mixtures

“…In UF 2D NMR, the scan-to-scan incrementation of a parameter value found in classic 2D NMR (e.g., of the t 1 evolution time) is replaced by a spatial parallelisation approach, in which the parameter value varies as a function of position in the sample. 141,142 This is achieved with the combined application of a frequency-swept pulse and a magnetic field gradient. Together with magnetic-resonance imaging methods that make it possible to effectively collect separate free-induction decay (FID) signal per sample slice, such spatial encoding provides a full 2D data set in a single scan of less than 1 second.…”

Absolute Metabolite Quantification Using Pure Shift NMR: Toward Quantitative Metabolic Profiling of Aqueous Biological Samples

“…Simple, robust quantification protocols, applicable to a wide variety of samples, have been established, giving access to the absolute quantification of the components in the mixture. , Moreover, in recent years, an increasing number of methods based on sophisticated pulse sequences have emerged, which has paved the way to the analysis of ever more complex samples. This is, for instance, the case for two-dimensional (2D) NMR or pure shift NMR experiments, − whose resolution enhancements make it possible to separate and identify the components of mixtures in various fields of application (organic chemistry, biology, etc.). It is also the case with hyperpolarization methods, which allow to dramatically push back the detection limits for the analysis of “real” samples (cells, fruit extracts, etc.…”