Tsunenobu Shigematsu

The solvent extraction of europium and barium with 1-aryl-3-methyl-4-aroyl-5-pyrazolones

Abstract Eleven 1-aryl-3-methyl-4-aroyl-5-pyrazolone derivatives were synthesized. Their acid dissociation constants were determined spectrophotometrically; there was a linear relationship between them and Hammetts σ values. Europium and barium ions were readily extracted into benzene and n-octyl alcohol, respectively, at very low pH.

Gas Chromatography of Rare Earth Chelates of Pivaloyltrifluoroacetone

The gas chromatographic behavior of Sc, Y, and rare earth chelates of a new β-diketone, pivaroyltrifluoroacetone (PTA), was investigated. PTA was synthesized by a Claisen condensation from pinacolin and ethyltrifluoroacetone. Sc, Y, Nd, Sm, Eu, Gd, Tb, Dy, Er, Yb, and Lu PTA chelates were prepared. Their elemental analyses and infrared spectra indicated that they were anhydrous tris chelates, and the TGA curves of the chelates proved their good volatile characteristics, showing approximately a 100% weight loss. Gas chromatograms of all the chelates and of mixtures of Sc, Y, and several rare earth chelates were obtained. Some relationships were observed between the retention time, the volatilization temperature, and the ionic radius of the central metal: With the decrease in the ionic radius, the retention time of the chelate decreased and the volatilization temperature became lower.

Determination of manganese in natural waters by atomic absorption spectrometry with a carbon tube atomizer.

Abstract The atomic absorption spectrometry of manganese was studied with carbon tube atomizers. Various inner diameters of the carbon tubes were studied: small bores gave higher sensitivity, but large bores gave higher reproducibility. A fairly linear calibration curve was obtained in the range of 1–6 ·10 -10 g of manganese with injection volumes of 5 μl. The detection limit was 1.5 ·10 -11 g and the relative standard deviation 3.5%. In 40-fold amounts, few salts interfered, but there were considerable interferences from 400 and 4000-fold amounts. Manganese in natural waters was determined by extracting it into diisobutyl ketone as the diethyldithiocarbamate; the amounts found lay in the range 0.5–33 p.p.b.

Thermogravimetric and gas-chromatographic study of neodymium, gadolinium and erbium β-diketone chelates

Summary Various β-diketone chelates of neodymium, gadolinium and erbium were prepared. Hydrate formation and hydroxyl content of the chelates were studied by i.r. spectra in the region 3000–3700 cm−1. The TGA curves of the chelates showed that dipivaloylmethane (DPM), isobutyrylpivaloylmethane (IBPM) and trifluoroacetylpivaloylmethane (TPM) chelates sublimed quantitatively at 150–270° ; diisobutyrylmethane (Gd, Er), pivaloylpropionylmethane (Er), trifluoroacetylisobutyrylmethane (Gd, Er), trifluoroacetyl-α-methylbutyrylmethane (Er) and trifluoroacetylisovalerylmethane (Er) chelates partially volatilized, and the other chelates decomposed without sublimation. Generally, the anhydrous tris-chelates sublimed quantitatively, and the basic rare earth β-diketonates and hydrated chelates decomposed. Among the β-diketones studied HIBPM, HDPM and HTPM seem to be useful reagents for the gas chromatography of the rare earth elements.

A highly sensitive spectrophotometric determination of palladium with chromal blue g and cetyltrimethylammonium chloride

Abstract A new spectrophotometric method for the determination of palladium with chromal blue G (Color Index 43835) and cetyltrimethylammonium chloride is described. The sensitivity of the color reaction between palladium and chromal blue G is greatly increased in the presence of cetyltrimethylammonium chloride. The palladium complex has maximal absorbance at pH 3.2–3.8 and at 670 nm. Beers law is obeyed over the range 0.08–1.4 p.p.m. palladium; the molar absorptivity is 1.01 · 10 5 l mol -1 cm -1 at 670 nm and the sensitivity is 1·10 -3 μg Pd cm -2 . The mole ratio of palladium and chromal blue G in the complex in the presence of cetyltrimethylammonium chloride is 1:3. Only scandium interferes when sodium fluoride is used as masking agent.

A highly sensitive spectrophotometric determination of gallium with Pontachrome Azure Blue B and cetyltrimethylammonium chloride

A new spectrophotometric method for the determination of gallium with Pontachrome Azure Blue B and cetyltrimethylammonium chloride is described. The sensitivity of the colour reaction between gallium and Pontachrome Azure Blue B is greatly increased in the presence of cetyltrimethylammonium chloride. The gallium complex has maximal absorbance at 680 nm and pH 6.0-6.6. Beers law is obeyed over the range 0.08-0.6 ppm of gallium; the molar absorptivity is 1.39 x 10(5) 1.mole(-1). cm(-1) and sensitivity 4.9 x 10(-4) mu/cm(2). The mole ratio of the complex, the formation constant and effect of interfering ions are described.

The Half Life of Tb

A sample of Gd/sub 2/O/sub 3/ was borabarded for four hours with 38.5- Mev alpha particles and the activity of Dy/sup 157/ produced by the ( alpha ,3n) reaction was separated from the target material. Terbium was separated from dysprosium by an ionexchange method. The decay rate of Tb/sup 157/ nuclei was determined from the counting rate of the K x rays in a well type crystal, and the K and L electron capture ratio was measured using a NaI(Tl) crystal covered with Al, corrected for absorption by the Al cover, self absorption, photopeak efficiency, and fluorescence yield. The half life of Tb/sup 157/ was estimated at 160 ction in DDT-C/ 40 yr; a decay mode was proposed. (C.E.S.)

Decay of 150Eu

Abstract Carrier free sources of 150Eu were prepared from bombardment of enriched 150Sm with 11 MeV deuterons and 9 MeV protons. The half-life was determined to be 12.79±0.08 h. The maximum energy of the negatons was 1.02±0.01 MeV and the Kurie plot showed almost an allowed shape. However, the experimental shape factor showed a slight deviation from the allowed one. This decay was estimated to be 0− or 1− to 0+ transition. Positons with a maximum energy of 1.8±0.3 MeV and an intensity of about 0.3% and the K X-ray following orbital electron capture with an intensity of 3.9±0.2% were found. In scintillation measurements 15 gamma rays were observed. Gamma gamma coincidence studies were performed at several gate windows for gamma rays and annihilation radiations. The decay scheme of 150Eu was constructed on the basis of these results.

Nonaqueous Liquid-Liquid Extraction. Extraction of Zinc from Methanol-Water Solution of Chloride by Trioctylphosph1Ne Oxide in Decaline

Abstract The distribution of zinc was studied between the decaline phase having tri-n-octylphosphine oxide (TOPO) and the methanol-water phase (4:1 in molar ratio) having chloride ion, and the stability constants of zinc with chloride in the methanolic solution were calculated from the extraction experiments (K1 = 2.4 × 103, K2 = 1.9 × 102at 298°K).

Nonaqueous Liquid-Liquid Extraction: Extraction of Zinc from Ethylene Glycol Solution of Chloride by Trioctylphosphine Oxide

Abstract The distribution of zinc between the toluene phase containing trioctylphosphine oxide (TOPO) and the nonaqueous ethylene glycol phase containing either hydrogen or lithium chloride has been investigated by using zinc-65. In the zinc-hydrogen or lithium-chloride-TOPO system, the complex ZnCl2-2TOPO may predominantly occur in the toluene phase, and only mononuclear zinc complexes appear to exist in the two phases.