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11.
Shuntaro Matsuta Noriaki Shima Hidenao Kakehashi Akari Ishikawa Ryutaro Asai Atsushi Nitta Misato Wada Shihoko Nakano Hiroe Kamata Yoshio Nishiyama Hirohisa Nagatani Hisanori Imura Munehiro Katagi 《Journal of mass spectrometry : JMS》2020,55(9)
Various cathinone‐derived designer drugs (CATs) have recently appeared on the drug market. This study examined the mechanism for the generation of dehydrated ions for CATs during electrospray ionization collision‐induced dissociation (ESI‐CID). The generation mechanism of dehydrated ions is dependent on the amine classification in the cathinone skeleton, which is used in the identification of CATs. The two hydrogen atoms eliminated during the dehydration of cathinone (primary amine) and methcathinone (secondary amine) were determined, and the reaction mechanism was elucidated through the deuterium labeling experiments. The hydrogen atom bonded to the amine nitrogen was eliminated with the proton added during ESI, in both of the tested compounds. This provided evidence that CATs with tertiary amine structures (such as dimethylcathinone and α‐pyrrolidinophenones [α‐PPs]) do not undergo dehydration. However, it was shown that the two major tertiary amine metabolites (1‐OH and 2″‐oxo) of CATs generate dehydrated ions in ESI‐CID. The dehydration mechanisms of the metabolites of α‐pyrrolidinobutiophenone (α‐PBP) belongs to α‐PPs were also investigated. Stable‐isotope labeling showed the dehydration of the 1‐OH metabolite following a simple mechanism where the hydroxy group was eliminated together with the proton added during ESI. In contrast, the dehydration mechanism of the 2″‐oxo metabolite involved hydrogen atoms in three or more locations along with the carbonyl group oxygen, indicating that dehydration occurred via multiple mechanisms likely including the rearrangement reaction of hydrogen atoms. These findings presented herein indicate that the dehydrated ions in ESI‐CID can be used for the structural identification of CATs. 相似文献
12.
T. Minamisono Y. Nojiri K. Matsuta K. Takeyama A. Kitagawa T. Ohtsubo A. Ozawa 《Hyperfine Interactions》1990,59(1-4):31-40
Electromagnetic moments of doubly closed shell ±1 nucleon nuclei were studied. Recent technical developments of the β-NMR
was shown that was applicable for the polarized β emitters. Also, the implication of those new moments were discussed especially
on the nuclear interactions and non nucleonic degrees of freedom. 相似文献
13.
T. Nagatomo H. Ueno M. Mihara K. Matsuta A. Yoshimi Y. Ichikawa K. Yamada H. Kawamura A. Ozawa T. Moriguchi Y. Ishibashi K. Asahi M. Uchida K. Suzuki T. Inoue Y. Hasama H. Iijima T. Sumikama M. Fukuda T. Minamisono 《Hyperfine Interactions》2010,198(1-3):103-107
Electric quadrupole coupling constant eqQ/h of the extremely proton-rich 23Al (I π ?=?5/2?+?, T 1/2?=?0.47 s) nucleus implanted into an Al2O3 single crystal has been measured for the first time, using the β-ray detecting nuclear quadrupole resonance method (β-NQR) in a high magnetic field. As a preliminary result, the quadrupole coupling constant was determined as |eqQ/h(23Al) |?=?2.66±0.77 MHz. Using the quadrupole coupling constant of 27Al in Al2O3 as a reference, the Q moment of the ground state of 23Al was extracted as |Q(23Al)|?~?160 mb, which is well explained by the shell model calculation in the sd-shell model space with the USD interaction. 相似文献
14.
Matsuta K. Onishi T. Fukuda M. Minamisono T. Mihara M. Sasaki M. Yamaguchi T. Miyake T. Sato K. Minamisono K. Ohsumi F. Muramoto Y. Oui S. Ha C. Tanaka K. Kidera K. Morishita A. Tsubota T. Sumikama T. Kitagawa A. Torikoshi M. Kanazawa M. Nishio T. Koda S. Ohtsubo T. Fukuda S. Nojiri Y. Momota S. Ozawa A. Yoshida K. Suzuki T. Kobayashi T. Tanihata I. Hanna S.S. Alonso J.R. Krebs G.F. Symons T.J.M. 《Hyperfine Interactions》1999,120(1-8):713-717
The degrees of nuclear spin polarization of 8,12B, 9C, 12N, 13O, 20,21F, 23Mg, 27Si and 39Ca produced in the high energy 12,13C, 16O, 22Ne, 24Mg, 28Si and 40Ca ions on Be collisions have been measured systematically, for the technical developments of the nuclear moment studies as
well as the hyperfine interaction studies by means of β-NMR technique. The fragment momentum dependences were well reproduced
by the simple kinematical model. Incident energy dependence and the mass dependence as well as the reaction angle dependences
were qualitatively explained by the mixing of the near and far side collisions.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
15.
Shin-ichi Kondo Kimihiro Endo Jun Iioka Keisuke Sato Yuka Matsuta 《Tetrahedron letters》2017,58(43):4115-4118
We have successfully prepared 5-(2-phenylethynyl)isophathalilc acid as a signaling unit and the corresponding derivatives for an anion receptor 2 and a barbiturate receptor 4. Receptor 2 showed characteristic UV–vis changes and dramatic fluorescence quenching upon the addition of anions and receptor 4 showed UV–vis and an OFF-ON fluorescence changes upon the addition of dibutylbarbituric acid based on the diphenylethyne moiety. 相似文献
16.
T. Sumikama M. Ogura Y. Nakashima T. Iwakoshi M. Mihara M. Fukuda K. Matsuta T. Minamisono H. Akai 《Hyperfine Interactions》2004,158(1-4):413-416
We observed the electric quadrupole interaction of 12B implanted in the interstitial site of TiO2 using β-NMR method. The electric field gradients including the direction of the principal axes were determined. The direction agreed
well with the theoretical calculation. 相似文献
17.
M. Mihara R. Matsumiya K. Matsuta K. Shimomura M. Fukuda J. Komurasaki D. Nishimura D. Ishikawa T. Nagasawa T. Izumikawa T. Minamisono 《Hyperfine Interactions》2007,178(1-3):69-72
In order to study the local electronic structure of nitrogen impurity in rutile TiO2, we have measured double-quantum NMR spectra of short lived β-emitter 12N(I = 1, T 1/2 = 11 ms) implanted into a rutile single crystal by means of the β-NMR technique. The resonance line obtained at room temperature is well accounted for by the second order shift due to the quadrupole interaction at the oxygen substitutional site. The spectrum at 25 K has shown the other lines than the central diamagnetic line shifted by 10?15 kHz to both sides, which has been already shown in the previous data obtained with a different crystal orientation and an external field. The present results supports the existence of a paramagnetic state formed by the substitutional nitrogen impurities. 相似文献
18.
T. Ohtsubo Y. Nakayama I. Minami M. Tanigaki S. Fukuda A. Kitagawa M. Fukuda K. Matsuta Y. Nojiri H. Akai T. Minamisono 《Hyperfine Interactions》1993,80(1-4):1051-1060
The quadrupole coupling constants of8Li and12B in hcp Mg and Zn are determined by use of a newly developed nuclear quadrupole resonance technique (NNQR) as ¦eqQ(8Li in Mg)/h¦=3.0±0.3 kHz, ¦eqQ(8Li in Zn)/h¦=33.5±2 kHz, and ¦eqQ(12B in Mg)/h¦=47.0±0.1 kHz. Correspondingly, the electric field gradients at room temperature are deduced: ¦q(8Li in Mg)¦=(3.81±0.39)×1018, ¦q(8Li in Zn)¦=(4.25±0.27)×1019, and ¦q(12B in Mg)¦=(1.47±0.03)×1020, all in V/m2. The experiments are compared with the results of first-principles super-cell band structure calculations which can treat local lattice relaxations around the impurity nuclei. The calculations show that the most favorable location of these light interstitials in hcp Mg is not the octahedral-like sites which have the biggest interstitial volume, but the basal trigonal sites with a local lattice expansion of as big as 30%. Calculated electric field gradients at the impurity nuclei reproduce the experimental values fairly well. 相似文献
19.
T. Minamisono T. Ohtsubo Y. Nakayama T. Araki K. Mashitani K. Matsuda E. Takahashi M. Tanigaki Y. Someda M. Tanaka A. Kitagawa M. Fukuda K. Matsuta Y. Nojiri 《Hyperfine Interactions》1992,73(3-4):347-356
Hyperfine interactions of β-emitting17F implanted in single crystals of NaF and CaF2 were studied. The nuclear magnetic moment of theT
π=5/2+ state was determined with an improved precision to be |μ(17F;π=5/2+,T
1/2=64.5s|=4.72130±0.00025. nm. Isoscalar magnetic moments of the doubly closed shell ±1 nucleon nuclei around mass number 16
were derived and the effective nucleon mass in the nucleus was discussed. 相似文献
20.
Naofumi Ohtsu Masaoki Oku Kazuo Obara Shun Ito Toetsu Shisido Kazuaki Wagatsuma 《Surface and interface analysis : SIA》2007,39(6):528-532
Oxidation behavior of NiAl alloy at low temperatures was studied. A NiAl plate was oxidized by exposure to ambient atmosphere at room temperature, heated at 473 K in air, and heated at 773 K in air. The oxide formed on the NiAl surface was investigated by angle‐resolved X‐ray photoelectron spectroscopy (AR‐XPS). Chemical composition and atomic concentration in the oxide layer were analyzed with factor analysis of XPS spectra. Exposure of the NiAl plate to the ambient atmosphere resulted in the formation of an Al2O3 layer along with a small amount of NiO. Oxidation of the NiAl plate at 473 K in air formed a film of double‐layered oxide; the top layer consisted of NiAl2O4 and a small amount of NiO, and the second layer was Al2O3. Successive oxidation at 773 K only changed the oxide‐layer thickness without changing the structure. Formation of oxide observed in the present study corresponds to the thermodynamic prediction for the oxidation behavior of NiAl at 1373 K. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献