Nuclear Magnetic Resonance Studies of ⁴³Ca

Abstract

The ratio of the Larmor frequencies of 43Ca and 37C1 has been measured and a magnetic moment for 43Ca of ^(43Ca2+ in D20) = -1.315645 (7) /uy; has been calculated. 43Ca chemi cal shifts have been determined in aqueous calcium salt solu tions with 43Ca in natural abundance, also at low concentra tions. The latter result is interesting for 43Ca studies in bio logical systems. Introduction 43Ca, the only stable Calcium isotope which can be studied by the NMR-method, has a natural abundance of 0.129%. Therefore there exist no 43Ca NMR studies in natural abundance, although 43Ca is an interesting element in biological systems. A few studies in this area were done by Bryant1 with enriched material.Jeffries2 has determined the nuclear magnetic moment of 43Ca, ju(43Ca) = -1.3152 (2) jUy by measuring the ratio of the Larmor frequencies of 43Ca and 2H in an aqueous solution of CaBr2 en riched to 68 percent 43Ca, with a paramagnetic cata lyst. With the optical pumping method, Olschewski 3 determined the nuclear magnetic moment on free 43Ca-atoms; the value is ja (43Ca) = -1 .3 1 5 37(60) juN .

Fourier transform nuclear magnetic resonance studies of199Hg

“…The NMR signal of 2~ with a relative intensity, which is 5 times smaller than that of 199Hg, was not observed with the described spectrometer. The cause of this fact is not so much the weak intensity-less intense signals have already been observed [27,28]as probably a large linewidth, because 2~…”

Precision measurement of the Ca+43 nuclear magnetic moment

“…Of particular interest are ions with magic numbers of nucleons [20]. Recently there has been significant theoretical [21][22][23][24][25][26][27] and experimental attention [28][29][30][31][32] given to the calcium isotopic chain as there exist two naturallyoccurring doubly-magic isotopes, 40 Ca and 48 Ca. The properties of the calcium isotopic chain can reveal new aspects of nuclear forces, such as three-body contributions [33] and the appearance of new magic numbers at extreme neutron-to-proton ratios [34].…”

“…Liquid NMR [47] −1.315645 (7) Liquid NMR [48 which the atom is measured. The chemical shift is challenging to calculate [40] and has led to significant disagreements between theory and experiment [16].…”

“…There exist three previous measurements of µ I for 43 Ca which are summarised in table I. Two measurements were made using NMR of liquid Ca salts [47,48], and the other by spectroscopy in an atomic vapour [49].…”

“…397 nm 393 nm µ I . From this, and previous NMR spectroscopy [48], we derive the shielding constant of 43 Ca 2+ ions in deuterium oxide σ. We conclude with a comparison to previous measurements.…”