Mobile High Resolution Xenon Nuclear Magnetic Resonance Spectroscopy in the Earth’s Magnetic Field

Appelt, Stephan; Häsing, F. Wolfgang; Kühn, H.; Perlo, Juan; Blümich, Bernhard

doi:10.1103/physrevlett.94.197602

Cited by 56 publications

(48 citation statements)

References 25 publications

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“…This is owing to the fact that the spectral lines are normally much broader than the line separation induced by chemical-shift differences. One exception is hyperpolarized xenon ( 129 Xe), which allows Earth's field Xe chemical-shift measurements in liquids with a precision comparable to that of superconducting magnets 19 . Second, only heteronuclear J-couplings can be measured in the Earth's field, because the chemical-shift differences for a given nuclear-spin species (<0.1 Hz) are smaller than the typical values of the homonuclear J-coupling constants (∼0.5−200 Hz).…”

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Chemical analysis by ultrahigh-resolution nuclear magnetic resonance in the Earth’s magnetic field

et al. 2006

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Increasing requirements of sensitivity and of spectral dispersion have driven the development of NMR magnets to higher and more homogeneous magnetic fields, which are obtained by immobile and expensive superconducting magnets. With the best field homogeneities available ( B/B ∼ 10 −9 over 1 cm 3 , where B is the magnetic field), ultrahigh-resolution carbon ( 13 C) NMR spectra at 4.2 T with an instrumental broadening below 50 mHz have been realized 2 . For 1 H high-field NMR spectroscopy (1-20 T), it is difficult to measure linewidths with an instrumental broadening below 100 mHz.We define our ideal NMR spectrometer by two requirements: first, it should measure NMR spectra with high resolution and all relevant NMR parameters, such as the longitudinal (T 1 ) and transverse (T 2 ) relaxation times, the chemical shift and the dipolar and J-coupling, in a single scan; and second, the spectrometer should be robust, low cost and mobile. Low cost and mobile means that heavy electro or superconducting magnets as well as superconducting quantum interference devices (SQUIDs) should be avoided. Single-scan and high-resolution NMR implies

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“…Figure 4 shows a complicated case, the 19 F spectrum of NFH. In the Earth's field, the NFH molecule is characterized by eight heteronuclear 1 H− 19 F J-coupling constants.…”

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Chemical analysis by ultrahigh-resolution nuclear magnetic resonance in the Earth’s magnetic field

et al. 2006

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“…Hyperpolarized (hp) 3 He and hp 129 Xe (both I ϭ 1͞2) have both been used in a wide range of NMR and magnetic resonance imaging (MRI) experiments that are otherwise impossible (3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15). In particular hp 3 He has been applied for medical MRI diagnosis of pulmonary diseases (16)(17)(18)(19).…”

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Hyperpolarized krypton-83 as a contrast agent for magnetic resonance imaging

Pavlovskaya

Cleveland

Stupic

et al. 2005

Proc. Natl. Acad. Sci. U.S.A.

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For the first time, magnetic resonance imaging (MRI) with hyperpolarized (hp) krypton-83 ( 83 Kr) has become available. The relaxation of the nuclear spin of 83 Kr atoms (I ‫؍‬ 9͞2) is driven by quadrupolar interactions during brief adsorption periods on surrounding material interfaces. Experiments in model systems reveal that the longitudinal relaxation of hp 83 Kr gas strongly depends on the chemical composition of the materials. The relaxationweighted contrast in hp 83 Kr MRI allows for the distinction between hydrophobic and hydrophilic surfaces. The feasibility of hp 83 Kr MRI of airways is tested in canine lung tissue by using krypton gas with natural abundance isotopic distribution. Additionally, the influence of magnetic field strength and the presence of a breathable concentration of molecular oxygen on longitudinal relaxation are investigated.NMR ͉ optical pumping ͉ pulmonary ͉ MRI ͉ xenon H igh nuclear spin polarization in noble gasses can be generated through rubidium vapor spin exchange optical pumping (RbSEOP) (1) and allows for NMR signal enhancements of many orders of magnitude (2). Hyperpolarized (hp) 3 He and hp 129 Xe (both I ϭ 1͞2) have both been used in a wide range of NMR and magnetic resonance imaging (MRI) experiments that are otherwise impossible (3-15). In particular hp 3 He has been applied for medical MRI diagnosis of pulmonary diseases (16)(17)(18)(19). One of the fundamental parameters with high diagnostic value for hp 3 He MRI is the spin-density that is a result of the helium concentration in a particular volume. Spin-density mapping of hp 3 He can be applied to visualize ventilation in lungs. Other useful parameters are 3 He diffusion that provides information about alveolar size distributions in lung tissue and hp 3 He relaxation that depends on oxygen partial pressure in lungs. In vivo MRI of airways with hp 129 Xe as a contrast agent (19-21) suffers from a lower sensitivity compared with hp 3 He. However, 129 Xe adds a further parameter not available by 3 He, namely, the chemical shift that allows for insights into the local environment of the xenon atoms (22-27). The 129 Xe chemical shift has been used extensively for research in materials science, engineering, and xenon dissolved in liquids including human blood (3,5,6,8,9,12,28). The chemical shift obtained from hp 129 Xe can be used to generate an in vivo MRI contrast that is a probe for gas perfusion in lungs (i.e., exchange of the gaseous xenon with the lung parenchyma) (29).3 He and 129 Xe are the only spin I ϭ 1͞2 stable isotopes of the noble gas group, but there are three more NMR active isotopes in this group with higher spin that possess a nuclear electric quadrupole moment. The three quadrupolar isotopes are 21 Ne (I ϭ 3͞2, natural abundance 0.27%), 83 Kr (I ϭ 9͞2, natural abundance 11.5%), and 131 Xe (I ϭ 3͞2, natural abundance 21%). Quadrupolar interactions in these noble gas atoms cause spin relaxation and coherent spin evolution that are probes for the shape, size, and symmetry of void spaces as well as the ...

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“…High resolution NMR spectroscopy with hyperpolarized molecules has been demonstrated in the Earth's magnetic field and close to zero field [10][11][12][13]. PHIP, where singlet state order (parahydrogen) is transferred into large observable nuclear polarization, offers an attractive means of hyperpolarization [14][15][16][17][18].…”

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Fundamental Aspects of Parahydrogen Enhanced Low-Field Nuclear Magnetic Resonance

et al. 2013

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We report new phenomena in low-field 1 H nuclear magnetic resonance (NMR) spectroscopy using parahydrogen induced polarization (PHIP), enabling determination of chemical shift differences, , and the scalar coupling constant J. NMR experiments performed with thermal polarization in millitesla magnetic fields do not allow the determination of scalar coupling constants for homonuclear coupled spins in the inverse weak coupling regime ( < J). We show here that low-field PHIP experiments in the inverse weak coupling regime enable the precise determination of and J. Furthermore we experimentally prove that observed splittings are related to in a nonlinear way. Naturally abundant 13 C and 29 Si isotopes lead to heteronuclear J-coupled 1 H-multiplet lines with amplitudes significantly enhanced compared to the amplitudes for thermally prepolarized spins. PHIP-enhanced NMR in the millitesla regime allows us to measure characteristic NMR parameters in a single scan using samples containing rare spins in natural abundance. DOI: 10.1103/PhysRevLett.110.137602 PACS numbers: 76.60.Àk, 33.25.+k, 82.56.Ub The established approach to liquid-state NMR spectroscopy in high fields is based on resolving NMR lines probing chemical shifts, J-coupling constants, and multiplicity. Those parameters are easily extracted from the spectra, because high-field experiments are typically performed in the weak coupling regime, where ) J is valid. The clearly separated spectral lines allow identification of molecular structure. In the presence of rare spins additional heteronuclear J-coupled multiplets arise [1,2].In the last decades various hyperpolarization technologies [3][4][5][6] and sensitive detection schemes [7][8][9][10] have rekindled the interest in low-field NMR. High resolution NMR spectroscopy with hyperpolarized molecules has been demonstrated in the Earth's magnetic field and close to zero field [10][11][12][13]. PHIP, where singlet state order (parahydrogen) is transferred into large observable nuclear polarization, offers an attractive means of hyperpolarization [14][15][16][17][18]. NMR spectroscopy with hyperpolarized J-coupled spins at zero and close to zero field [19][20][21] has been demonstrated. In these cases the presence of rare spins (e.g., 15 N) in the molecule is required to yield observable transitions in J-coupled spin systems. Close to zero field there are still ambiguity problems for molecules with more than two chemical groups and the chemical shift information is lost [22]. The drawbacks of low-field NMR spectroscopy for pure 1 H spin-systems with thermal polarization are the low signal-to-noise ratio (SNR) and the loss of J-coupling and chemical shift information.We show striking differences between the spectra obtained by PHIP and thermal prepolarization in low magnetic fields. In the following we detail how low-field PHIP spectra provide access to J and in addition to benefitting from the inherent SNR enhancement that allows for single-shot acquisition of compounds containing rare spins in natural abundan...

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Mobile High Resolution Xenon Nuclear Magnetic Resonance Spectroscopy in the Earth’s Magnetic Field

Cited by 56 publications

References 25 publications

Chemical analysis by ultrahigh-resolution nuclear magnetic resonance in the Earth’s magnetic field

Chemical analysis by ultrahigh-resolution nuclear magnetic resonance in the Earth’s magnetic field

Hyperpolarized krypton-83 as a contrast agent for magnetic resonance imaging

Fundamental Aspects of Parahydrogen Enhanced Low-Field Nuclear Magnetic Resonance

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