Combination of OPSY and PhD-PHIP results in enhanced sensitivity in PHIP

Understanding Heterogeneous Catalytic Hydrogenation by Parahydrogen-Induced Polarization NMR Spectroscopy

“…OPSY (only parahydrogen spectroscopy) is a gradient-based PHIP NMR method, which can selectively observe the polarized signals while the thermally polarized signals are filtered. Based on this method, the spectra can be “cleared”, leading to enhanced sensitivity. , Besides, PhD-PHIP (parahydrogen discriminated-PHIP) can act as an acquisition block that prevents signal cancellation in the presence of magnetic field inhomogeneities to increase the resolution and sensitivity of the spectra …”

“…135,136 Besides, PhD-PHIP (parahydrogen discriminated-PHIP) can act as an acquisition block that prevents signal cancellation in the presence of magnetic field inhomogeneities to increase the resolution and sensitivity of the spectra. 137 The rapid development of HET-PHIP enforces the function of the NMR technique and opens the door to new applications in chemistry, material science, and biology. For example, HET-PHIP has shown high application potential in the field of hyperpolarized magnetic resonance imaging (MRI) to obtain 2D and 3D imaging of the catalyst reactor and gas product distribution in the catalyst bed.…”

Discrimination of PHIP Signals Through their Evolution in Multipulse Sequences

“…It is important to remark that, although at first sight it seems that the same effect is achieved by the use of a digital filter, the situation is not equivalent. In a scenario of relatively low hyperpolarized level, either due to poor reaction efficiency or low concentration of reactants, the receiver gain is limited by the thermal background, even if it is out of the frequency range of the digital filter [39,40] because prior to the filtering process the whole signal is acquired. Therefore, independently of the use of digital filters during the acquisition with PhD-PHIP, using OPSY as a filter allows rising the receiver gain level, resulting in sensitivity enhancement.…”

“…Recently, we demonstrated the convenience of this combination of sequences in a series of experiments performed with the hydrogenation of 1-hexyne. [40] In Figure 4a, the chemical reaction is depicted, along with the NMR spectrum acquired after a 45°pulse, where a very low hyperpolarization level is achieved for demonstrative purposes. Figure 4b shows the signal acquired with the original OPSY, [19] where the receiver gain level has been bumped up to enhance the SNR.…”

“…c) OPSY and PhD-PHIP combined to improve resolution and sensitivity simultaneously. Adapted with permission from Ref [40]. Copyright (2019) Elsevier.…”