Authors:N. Ishioka, H. Matsuoka, S. Watanabe, A. Osa, M. Koizumi, T. Kume, S. Matsuhashi, T. Fujimura, A. Tsuji, H. Uchida, and T. Sekine
The positron emitters11C,13N and18F and their labeled compounds have been produced for studies on plants using a newly developed positron emitting tracer imaging
system. Although this system covers, at present, a limited area in a plant, the distribution of the positron emitter fed into
the plant can be visualized dynamically. Further development of positron-emitter-labeled compounds is expected to elucidate
the physiological function of plants in vivo.
The current experimental and computational research in carbon clusters pointed out a need for enumeration of all possible12C/13C isotopoments of the C2v cyclic odd-numbered carbon clusters Cn. It is shown that the number of the isotopomers is given by 2k–1(2k–1+1) withk=(n+1)/2. Some illustrative computed structure and energy data for the clusters are reported, too.
Authors:E. Aragon, K. Jardet, P. Satre, and A. Sebaoun
The Al–Ga–Zn ternary phase diagram presents two isobaric invariant reactions: a eutectic at 231C and a metatectic at 1231C
[1–3]. Calorimetric measurements on the two isobaric invariant reactions have been carried out. First the Tammann method has
enabled us to determine the composition of their limits on five isopletic cross sections. Then, the compositions of the invariant
phases have been determined.
The set of all 51 possible12C/13C isotopomers of a C8 cluster of D2d symmetry has been studied by means of the harmonic vibration analysis based on the force field resulting from the second order Møller-Plesset (MP2) perturbation treatment with the 6-31G* basis set. The isotopomers can undergo 200 isomerizations which can be classified into 5 distinct groups using the properties of sums of the squares of harmonic vibrational frequencies.
Authors:Tiecheng Ran, Ruili Liu, Juanjuan Yin, Jianhua Zhu, Wenxin Li, and Qingnuan Li
A procedure for labeling of a fullerene derivative 1-[N',N'-bis(2-chloroethyl)-4-aminophenyl]-N-methyl-fullereno-C60-[1,9-c]pyrrolidine (C60-C13H18N2Cl2) with 125I is reported. The compound was first iodinated with a large excess of iodine monochloride and then radiolabeled by isotopic
exchange with Na125I in a toluene-water two-phase system. The dependence of the radiolabeling yield on the reaction temperature and exchange
time was examined. The radiolabeling yield of the compound was as high as 94% after heating for 2 hours at 130 °C.
Authors:G. Mohamed, F. Nour El-Dien, and N. El-Gamel
The present work aims chiefly to study the thermal behaviour of complex compounds with general formula: [M(HL)
yH2O (where HL=C13H11N4O2=6-(2-pyridylazo)-3-acetamidophenol (PAAP), M=Cu(II), Zn(II), Cd(II) and Fe(III) x=1, 3; y=2, 5) while A=CH3COO– (Ac), Cl2. The second formula is [M(H2L)
xH2O]Cl2yH2O, (where H2L=C13H12N4O2 (PAAP), M=Ni(II), Co(II) x=3; y=4, 6). The compounds were identified by elemental analysis, FT-IR spectra and TG/DTG,DTA methods. It was found that during the thermal decomposition of complex compounds water molecules of crystallization are released in the first step. In the next step the pyrolysis of organic ligand takes place. Metal oxide remained as a solid product of the thermal decomposition. Mass spectroscopy has been used for the determination of the thermal decomposition on the intermediate products. It was found that the thermal stability of the studied compounds increases as the ionic radii decreases. The activation energy E, the entropy change
S*, the enthalpy
H* change and Gibbs free energy change
G* were calculated from TG curve.
Free and bound aroma (precursors) compounds of the Muscat of Alexandria wines and the effect of skin contact (7 h, at 15 °C) on aroma composition have been investigated. The aroma compounds, extracted with the pentan-dichloromethane (2:1) method and Amberlite XAD-2 resin, were analysed by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). A total of 41 free volatile compounds (12 esters, 8 acids, 7 terpenes, 5 alcohols, 4 phenols, 3 C-6 compounds, 2 carbonyl compounds) and 28 bound compounds (10 terpenes, 2 alcohols, 2 C-6 compounds, 5 fatty acids, 6 phenols, 2 C-13 norisoprenoids, 1 carbonyl compound) were identified in Muscat of Alexandria wines. Skin contact treatment increased the total free and bound aroma compound levels, and improved the wine quality by affecting the intensity as well as the quality of aroma.
Reversed-phase high-performance liquid chromatography with u.v. detection was applied for rapid and sensitive determination of pertechnetate in99Mo/99mTc generator eluates, using a mixture solvent of acetonitrile and 0.04M aqueous acetate buffer (1/1) containing a few volume percentage of 0.5 M tetra-n-butylammonium hydroxide as the mobile phase. Employing a -bondapak C13 column, the TcO
species was separated, monitored with absorbance at 254 nm, and observed at the retention time of 3.5 min. The detection limit was found to be 5.2·10–10 g of Tc for each injection. Total Tc contents in the99mTc eluates from clinically-used99Mo/99mTc generator were analyzed by this technique. The99mTc (99Tc) species was separated from the contaminant99Mo. This method was found to be useful for the purification of99mTc (99Tc) as well as the determination of total Tc content.
Authors:K. Shikano, K. Masumoto, T. Ohtsuki, and M. Katoh
We studied the production of nine typical organic analytical reagents labeled with11C,13N and18F by irradiation with charged particles and bremsstrahlung and the purification of labeled compounds with HPLC and sublimation.
As a result, we found that six reagents, α-naphthol, β-naphthol, quinoline, α-nitroso-β-naphthol, 8-hydroxyquinoline, and
1,10-phenanthroline H2O could be labeled with11C by bombarding a mixture of each reagent and boron with protons. More than 10% of the11C was successfully exchanged with carbon atoms in the original reagents. We also found that sublimation is useful for purifying
8-hydroxyquinoline labeled with11C. The extraction property of11C-labeled 8-hydroxyquinoline between water and chloroform could be easily monitored by radioactivity measurement.
Authors:O. Kindel, F. Herrmann, L. Schmidt, and P. Patzelt
In kerosene samples from nuclear fuel reprocessing, iodoalkanes with chain-lengths from C4 to C13 have been identified. The kerosene samples were purified by means of solid-phase extraction. By this method other fission products like125Sb and106Ru were quantitatively removed from the solution. The only remaining radioactive nuclide was thus129I. The iodoorganic compounds in the kerosene from the solvent were enriched from 6000 Bq/L to 100 000 Bq/L129I by vacuum distillation. Chromatographic separation by HPLC, fractionation, and -measurement of the fractions showed that at least one polar and one nonpolar iodoorganic compound were present. Derivatisation of the iodoorganic compounds with, 1,4-diazabicyclo-2,2,2-octane to quatermary ammonium salts and252Cf plasma desorption mass spectrometry of the products revealed that the main iodoorganic constituents in the kerosene were iodobutane as polar and iodododecane as nonpolar compound in approximately equal concentrations.