High-Pressure Clinical-Scale 87% Parahydrogen Generator

Abstract

We present an automated parahydrogen generator (Para-Sun) for clinical-scale applications in parahydrogen-induced polarization (PHIP) and signal amplification by reversible exchange (SABRE) at high pressures. The device employs a vacuum-pumped, Sunpower cryo-cooler (typically employed for cooling cellular network antennas) to achieve up to ∼87% parahydrogen enrichment at a temperature as low as ∼40 K and a maximum outlet pressure of ∼490 PSI. The device reaches the target temperature set-point in under 1 h. It employs a FeO(OH) catalyst for the ortho-to para-state conversion. A mass-flow controller (MFC) facilitates the controlled flow of H 2 gas at a rate of 150 standard cubic centimeters per minute (sccm). This design bridges the gap between rudimentary 50% enrichment liquid-N 2 baths and far costlier, near-unity-enrichment configurations employing high-H 2 throughputs and <25 K temperatures. The design presented here should be of interest for those pursuing a wide variety of PHIP applications, including those involving the production of inhalable or injectable hyperpolarized contrast agents for biomedical imaging.

Heterogeneous 1H and 13C Parahydrogen‐Induced Polarization of Acetate and Pyruvate Esters

“…p‐H 2 enrichment was achieved using custom‐built ParaSun p‐H 2 generator based on cryocooler module (SunPower, P/N 100490, CryoTel GT; a detailed description of the generator was published elsewhere [75,83] ). The generator was operated at 40–68 K, resulting in ca.…”

Parahydrogen‐Induced Polarization of Amino Acids

“…Several instruments have been developed to aid the production of p H 2 . [ 34 , 35 , 36 ] As the o H 2 – p H 2 transition is forbidden under conservation of quantum numbers, a conversion catalyst such as FeO(OH) is used. Once produced, p H 2 may be conveniently stored in a bottle and used on demand.…”

Parawasserstoff‐induzierte Polarisation von Aminosäuren

“…Zur Herstellung von pH 2 wurden mehrere Geräte entwickelt. [34][35][36] Da der oH 2 -pH 2 -Übergang unter Erhaltung der Quantenzahlen verboten ist, wird ein Umwandlungskatalysator wie FeO(OH)-Granulat verwendet. Einmal hergestellt, kann pH 2 fürl ängere Zeit in Flaschen aufbewahrt und bei Bedarf verwendet werden.…”