• Journal of the Korean Magnetic Resonance Society
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• v.21 no.4
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• pp.126-130
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• 2017

In the developed NMR hyperpolarization techniques, Parahydrogen-Induced Polarization (PHIP) technique is widely utilized to overcome the low sensitivity of the NMR/MRI. Parahydrogen generator is essential to produce high spin order of parahydrogen molecule. Commercial parahydrogen generator is well developed with user-friendly systems. However, it has drawbacks of long preparation time (~ 2h including cooling down time of 1h) and high cost (~ 200 million won) for the commercial setup. We designed a simple and portable parahydrogen generating system with low cost (~ 2 million won), which produce polarization in less than 1 min. With the designed parahydrogen generator, we successfully performed the PHIP with Wilkinson's catalyst on styrene. This study will broaden the parahydrogen based polarization transfer study on many researchers by providing the simple portable and low cost parahydrogen generator.

• Journal of the Korean Magnetic Resonance Society
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• v.22 no.1
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• pp.1-9
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• 2018

Among several NMR hyperpolarization techniques, parahydrogen-based hyperpolarization technique is recently extensively utilized to enhance the sensitivity of the conventional NMR/MRI spectroscopy. Two mostly investigated research topics are PHIP (Parahydrogen Induced Polarization) and SABRE (Signal Amplification By Reversible Exchange), which are commonly using the parahydrogen as the source of hyperpolarization. Those researches have been considered as the promising techniques that could provide hyperpolarized states on the ambient substrates including biologically important materials. Therefore, based on their potentials, we briefly reviewed several important experimental results on those topics after introducing the basic principle of parahydrogen and its generation with conceptual explanations. We hope this review will broaden the parahydrogen-based hyperpolarization transfer study on many researches in Korea.

• Journal of the Korean Magnetic Resonance Society
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• v.23 no.1
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• pp.6-11
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• 2019

Parahydrogen induced hyperpolarization (PHIP) technique is extensively studied to increase the sensitivity of the conventional NMR spectroscopy and recently try to apply this advanced technique into the revolutionary future of the MRI. The other hyperpolarization technique, which is widely utilized, is DNP (Dynamic Nuclear Polarization)-based hyperpolarization one. Despite its great advances in these fields, it contains several drawbacks to overcome: fast relaxation time, expensive equipment is needed, long build-up time is required (several hours), and batch scale material is hyperpolarized. To overcome all those limitations, one can effectively harness the hyperpolarized spin state of parahydrogen. One important step for utilizing the spin state of parahydrogen is doing well-developed experiments of ALTADENA and PASADENA. Based on those concepts, we successfully obtain the hydrogenation signals of ALTADENA and PASADENA from styrene by using benchtop NMR spectrometer. Also those signals were conceptually analyzed and confirmed with different mechanisms. To our best knowledge, those experiments using 1.4T (benchtop NMR) is the first reported one. Considering these experiments, we hope that parahydrogen-based hyperpolarization transfer studies in NMR/MRI will be broadened in Korea in the future.

• Journal of the Korean Chemical Society
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• v.45 no.4
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• pp.293-297
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• 2001

The existing vapor pressure measurements reported in the literature for parahydrogen between the triple point and the critical point have been employed to establish the constants and exponent of the following equation in the form of reduced vapor pressure and reduced temperature: ln $lnP_r=2.64-{\frac{2.75}{T_r}}+1.48129lnT_r+0.11T^5_r$Only the normal boiling point ($T_b$= 20.268K), the critical pressure ($P_c$= 1292.81 kPa), and the critical temperature ($T_c$= 32.976K) are necessary to calculate the vapor pressure for an overall average deviation of 0.21% for 153 experimental vapor pressure data.