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A continuous‐flow, high‐throughput, high‐pressure parahydrogen converter for hyperpolarization in a clinical setting
Author(s) -
Hövener JanBernd,
Bär Sébastien,
Leupold Jochen,
Jenne Klaus,
Leibfritz Dieter,
Hennig Jürgen,
Duckett Simon B.,
Elverfeldt Dominik
Publication year - 2013
Publication title -
nmr in biomedicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.278
H-Index - 114
eISSN - 1099-1492
pISSN - 0952-3480
DOI - 10.1002/nbm.2827
Subject(s) - hyperpolarization (physics) , spin isomers of hydrogen , chemistry , continuous flow , volumetric flow rate , pyridine , bar (unit) , high pressure , analytical chemistry (journal) , chromatography , hydrogen , thermodynamics , mechanics , physics , nuclear magnetic resonance spectroscopy , stereochemistry , organic chemistry , medicinal chemistry , meteorology
Pure parahydrogen (pH 2 ) is the prerequisite for optimal pH 2 ‐based hyperpolarization experiments, promising approaches to access the hidden orders of magnitude of MR signals. pH 2 production on‐site in medical research centers is vital for the proliferation of these technologies in the life sciences. However, previously suggested designs do not meet our requirements for safety or production performance (flow rate, pressure or enrichment). In this article, we present the safety concept, design and installation of a pH 2 converter, operated in a clinical setting. The apparatus produces a continuous flow of four standard liters per minute of ≈98% enriched pH 2 at a pressure maximum of 50 bar. The entire production cycle, including cleaning and cooling to 25 K, takes less than 5 h, only ≈45 min of which are required for actual pH 2 conversion. A fast and simple quantification procedure is described. The lifetimes of pH 2 in a glass vial and aluminum storage cylinder are measured to be T 1C (glass vial) = 822 ± 29 min and T 1C (Al cylinder) = 129 ± 36 days, thus providing sufficiently long storage intervals and allowing the application of pH 2 on demand. A dependence of line width on pH 2 enrichment is observed. As examples, 1 H hyperpolarization of pyridine and 13 C hyperpolarization of hydroxyethylpropionate are presented. Copyright © 2012 John Wiley & Sons, Ltd.