Rapid determination method of radiocesium in sea water by cesium-selective resin

A rapid and precise method of determining radiocesium corresponding to 5 mrem/y, the Japan AEC's guideline, was proposed. The development and practical performance of cesium-selective resin and the determination method was described in this paper. The resin was prepared by the formation of ammonium molybdophosphate in the structure of Amberlite XAD-7 resin. It took only 3 hours to carry out all the procedures the authors proposed. This value represents 1/10∼1/2 of the time of conventional method. The concentration of¹³⁷Cs and¹³⁴Cs in sea water was determined to be 0.13∼0.16 pCi/1 and less than 7.1·10⁻² pCi/1, respectively.     

Diastereomeric Difference of the Self-Inclusion Complex of N(N′-Formyl-Phenylalanyl)-Deoxyamino-β-Cyclodextrin Caused by the Interaction between the Arm and the Rim of the Cavity

A complete assignment of proton resonances for N(N-formyl d-phenylalanyl)-deoxyamino--cyclodextrin (1d) was performed by means of 1D and 2D NMR,¹H–^1H-COSY, ¹H–^13C-COSY, TOCSYand NOESY spectroscopy. Based on 2D-NMR ROESY and circular dichroism spectroscopy, the conformation of 1d was determined; the phenyl group stays inside the distorted cyclodextrin (CyD) cavity forming a self-inclusion complex, which is almost the same as N(N-formyl l-phenylalanyl)-deoxyamino--CyD (1l). The remarkable diastereomeric difference was observed in the chemical shifts of H(5) and H(6) protons at the narrow rim of the CyD cavity and induced circular dichroism spectra. These results suggest the existence of hydrogen bonds between the hydroxyl group on CyD and the amide groups on the arms, which provides the difference in the molecular recognition properties.     

Preparation of phosphorus-containing polymers—XVI. Synthesis of phosphorus-containing polyanhydride-imides

Phosphorus-containing polyanhydride-imides were synthesized from N,N-bis(4-carboxyphthalimido)-3,3′-diphenylalkylphosphine oxide, 3,3′-[N,N′-bis(4-carboxyphthalimido)]benzophenone and their mixtures in two steps via the diacetyl derivatives of the bisimide-carboxylic acids. The resulting polymers have reduced viscosities of 0.06–0.14 dl/g and are soluble in polar aprotic solvents such as DMA, DMF and DMSO, and conc. H₂SO₄ etc. They have good hydrolytic stability for moisture and water. Phosphorus-containing polymers have little heat-resistance and poor flame-retardance. The benefit of incorporating phosphorus in the polymers is small.     

Stable and lipophilic technetium-99m dithiosemicarbazone complexes with 5-6-5 membered chelate ring structure

Modification of the chelate ring structure of technetium-99m (99mTc) dithiosemicarbazone (DTS) chelate was carried out in pursuit of a more stable and lipophilic compound. A new DTS chelating molecule, pentane-2,4-dione bis(N-methylthiosemicarbazone) (PETS), with a 5-6-5 membered chelate ring structure, was synthesized and labeled with 99mTc, PETS generated two 99mTc compounds as major products. Both had much higher stability and lipophilicity than a 5-5-5 membered 99mTc DTS compound, as well as great stability in plasma. Both 99mTc-PETS compounds were rapidly extracted by the brain and heart when injected into mice. Thus, the modified chelate ring structure afforded a preferable characteristics to DTS chelate as for the chelating site for technetium radiopharmaceuticals.     

High-performance liquid chromatographic determination of taurine in biological fluids by post-column fluorescence reaction with thiamine.

A high-performance liquid chromatographic method is described for the selective determination of taurine in biological fluids by post-column fluorescence reaction. Taurine was separated on an adsorption-distribution type Shodex Ionpac KC-811 column. Then it was converted with hypochlorite into the corresponding N-chloramine, which was allowed to react with thiamine to give fluorescent thiochrome. As little as 6 ng per injection of taurine could be determined. The average recoveries of spiked taurine in serum and urine were 99.5 +/- 2.7 and 101.8 +/- 2.9%, respectively. The method could be applied to the assay of taurine in human serum and urine with simple pretreatment.     

Diaminothiazoles and diaminothiophenes

Several 2,4-diaminothiazoles and 2,4-diaminothiophenes could be easily obtained by metallation using LDA from aminomethylthiomethylenecyanamides $\text{2}$ and aminomethylthiomethylenemalononitrile, respectively.     

Stereoselective synthesis of tetrasubstituted (Z)-alkenes from aryl alkyl ketones utilizing the Horner-Wadsworth-Emmons reaction

Tetrasubstituted (Z)-alkenes were readily prepared through the Horner-Wadsworth-Emmons reactions of methyl 2-[bis(2,2,2-trifluoroethyl)phosphono]propionate with aryl alkyl ketones by employing Sn(OSO(2)CF(3))(2) and N-ethylpiperidine.     

Uranium determination by133Xe in meteorites; comparative study with fission track and/or239Np methods and thermal release character of133Xe

Uranium concentrations in three types of inclusions of the Allende (C III), a bulk sample of the Plainview (H5), and a bulk and 5 to 15 density separates of the Huckitta pallasite were determined and discussed by comparing the results from homogenized fission track and/or²³⁹Np analyses with the¹³³Xe results. Stepwise heating experiment revealed that the¹³³Xe release from the Plainview is bimordal and incomplete by a simple heating at 1600 °C, and that the¹³³Xe releases in the Huckitta bulk and metallic samples are multitudinous but can be extracted rather completely at 1600–1700 °C. In the Huckitta, uranium-rich phase (∼100 ppb) was in the lightest density fraction of d=2.9–3.3, but the bulk uranium was found to be mostly from the heavy metal-rich fraction of d>4.2.