Utilization of SABRE-derived hyperpolarization to detect low-concentration analytes via 1D and 2D NMR methods.

The characterization of materials by the inherently insensitive method of NMR spectroscopy plays a vital role in chemistry. Increasingly, hyperpolarization is being used to address the sensitivity limitation. Here, by reference to quinoline, we illustrate that the SABRE hyperpolarization technique, which uses para-hydrogen as the source of polarization, enables the rapid completion of a range of NMR measurements. These include the collection of (13)C, (13)C{(1)H}, and NOE data in addition to more complex 2D COSY, ultrafast 2D COSY and 2D HMBC spectra. The observations are made possible by the use of a flow probe and external sample preparation cell to re-hyperpolarize the substrate between transients, allowing repeat measurements to be made within seconds. The potential benefit of the combination of SABRE and 2D NMR methods for rapid characterization of low-concentration analytes is therefore established.