title: Singlet order conversion and parahydrogen-induced hyperpolarization of13C nuclei in near-equivalent spin systems.
abstract: We have demonstrated two radiofrequency pulse methods which convert the nuclear singlet order of proton spin pairs into the magnetisation of nearby13C nuclei. These irradiation schemes work well in the near-equivalence regime of the three-spin system, which applies when the difference in the two1H-13C couplings is much smaller than the1H-1H coupling. We use pulse sequences to generate thermally polarized singlet states in a reproducible manner, and study the singlet-to-magnetisation transfer step. Preliminary results demonstrate a parahydrogen-enhanced13C polarization level of at least 9%, providing a signal enhancement factor of more than 9000, using 50% enriched parahydrogen.
authors.affiliation: University of Southampton, SO17 1BJ, UK.
authors.forename: James
authors.initials: J
authors.lastname: Eills
authors.affiliation: University of Southampton, SO17 1BJ, UK.
authors.forename: Gabriele
authors.initials: G
authors.lastname: Stevanato
authors.affiliation: Goethe-Universität, 60323 Frankfurt, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Bengs
authors.affiliation: University of Southampton, SO17 1BJ, UK.
authors.forename: Stefan
authors.initials: S
authors.lastname: Glöggler
authors.affiliation: University of Southampton, SO17 1BJ, UK.
authors.forename: Stuart J
authors.initials: SJ
authors.lastname: Elliott
authors.affiliation: University of Southampton, SO17 1BJ, UK.
authors.forename: Javier
authors.initials: J
authors.lastname: Alonso-Valdesueiro
authors.affiliation: University of Southampton, SO17 1BJ, UK.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Pileio
authors.affiliation: University of Southampton, SO17 1BJ, UK. Electronic address: mhl@soton.ac.uk.
authors.forename: Malcolm H
authors.initials: MH
authors.lastname: Levitt
keywords: Hyperpolarization; PHIP; Parahydrogen; SLIC; Singlet states