SABRE hyperpolarization enables high-sensitivity ¹H and ¹³C benchtop NMR spectroscopy

Abstract

Benchtop NMR spectrometers operating with magnetic fields of 1–2 T at sub-ppm resolution coupled with SABRE hyperpolarization show great promise as analytical platforms that can be used outside the traditional laboratory environment.

Quantitative In Situ Monitoring of Parahydrogen Fraction Using Raman Spectroscopy

“…Between intervals, the PB held the gas pressure constant at 5 bar in the FT. The polariser box has previously been used to automate SABRE NMR experiments, 19,20,28,29 but in this case it was simply used to control the flow of gas out of the pH 2 generator.…”

“…This control unit is normally used to control the input of pH 2 into a mixing chamber used for hyperpolarisation experiments. 19,20,28 In this case the pneumatic control was used to regulate the pressure in the flow tube, and to control the flow of gas out of the pH 2 generator. The Raman laser was focussed onto the inside of the glass tube to provide in-situ analysis of the composition of the H 2 gas flowing directly out of the generator and into the control unit.…”

“…17 The research group at the University of Strathclyde has an in-house built pH 2 generator, which is used to provide gaseous pH 2 for signal amplification by reversible exchange (SABRE) hyperpolarisation studies on a bench-top NMR spectrometer. [18][19][20] To validate the hyperpolarisation experiments, it is desirable to be able to rapidly monitor the pH 2 fraction produced by this generator. The two spin isomers differ slightly in several physical properties, such as: heat capacity, vapour pressure, speed of sound, and thermal conductivity.…”

Rapid13C NMR hyperpolarization delivered frompara-hydrogen enables the low concentration detection and quantification of sugars

“…41,48 Since the polarization is produced ex situ it is also independent of detection eld, which means detection can occur on signicantly cheaper benchtop devices. [49][50][51] The applicability of SABRE is not limited to 1 H NMR and can be applied to many different nuclei such as 13 C, 52-54 19 F, 55,56 and 15 N, [57][58][59] among others. 60,61 In the case of 13 C and 15 N, the resonance condition for SABRE occurs at much lower magnetic elds, so PTFs of around 5 mG are required for the direct transfer of polarization from the catalysts hydride ligands.…”

Hyperpolarised 1H–13C Benchtop NMR Spectroscopy

“…Popular hyperpolarisation techniques include Dynamic Nuclear Polarisation (DNP) [41][42][43] and Parahydrogen-induced polarisation (PHIP) [44][45][46]. One relatively inexpensive method, which has been successfully implemented at low-field, is a PHIP-based method called signal amplification by reversible exchange (SABRE) [47][48][49]. SABRE catalytically transfers the latent polarisation in parahydrogen (p-H 2 , the NMR-silent singlet spin isomer of H 2 ) to a target molecule without chemical alteration of the target.…”