[en] Isotope effects of some elements in chemical exchange reaction were investigated by use of liquid-liquid extraction, liquid membrane or chromatographic separation. Cyclic polyether was used for every method. All polyethers used in a series of the studies were made clear that they distinguished the isotopes not only by their nuclear masses but also by their nuclear sizes and shapes. Chromium isotopes, for example, were recognized to have enrichment factors being proportional to δ< r²> which is a parameter to show field shift or the nuclear size and shape of the isotope. It follows that the chromium isotopes are separated not by their masses but by their field shift effects. Nuclear spin also played a great role to separate odd mass number isotopes from even mass number isotopes in even atomic number elements. Contribution of the nuclear spin (I=3/2) of ⁵³Cr to total enrichment factor, ε_53/52 = -0.00028, for ⁵³Cr to ⁵²Cr was observed to be, ε_spin = -0.0025. (author)

[en] A pulse counting method has been used to determine gains of an electron multiplier for various ions. A 16-stage box and grid type electron multiplier with copper-beryllium dynodes has been employed in equipment to a single focusing mass spectrometer. The condition, where the gain determined by the pulse counting method becomes almost identical to that by a Faraday cup method for each of various ions, has been discussed. (author)

[en] We examined an analytical procedure for accurate determination of ¹⁴C concentrations in elemental carbon (EC) of an aerosol in the atmosphere. When carbon dioxide released by a combustion of EC is converted to graphite for ¹⁴C measurement with accelerator mass spectrometry (AMS), sulfur, nitrogen and halogens co-released impede the conversion to graphite. We examined an appropriate condition for effective formation of graphite on metallic Fe powder. We used Ag wire and Sulfix for removing halogens and sulfur oxides and also used a reduced copper metal for reduction of nitrogen oxides to nitrogen gas. The following condition was used: 0.1 mm in diameter Ag wire of 100cm and reduced copper metal of about 30 mg were added in a vycol tube with about 64 mg of CuO during the EC combustion at 900degC for 1 hour. In addition, CO₂ evolved was heated at 350degC with Sulfix of about 20 mg in a pyrex tube. We obtained a yield up to 70% during the process to convert EC to graphite. Δ¹⁴C values of EC in aerosol were measured for 3 sets of samples: two from mountainous areas of Ikawa and one from Mt. Norikura and an urban area, Shizuoka University. The Δ¹⁴C values of EC at Mt. Norikura, (ave. -636per mille) were similar to those at Shizuoka University (ave. -717per mille), while the Δ¹⁴C values in Ikawa (ave. -282per mille to ave. -349per mille) were higher than those of the other sites. (author)

[en] A new technique for the removal of isobaric interferences on Ba has been developed for ICP-mass spectrometer. Mass spectrometric interferences on Ba by ¹³⁸La⁺, ¹³⁶Ce⁺, or ¹³⁸Ce⁺ isobaric signals were effectively eliminated by a selective production of oxide ions. The La⁺ and Ce⁺ ions could be quantitatively converted to oxide ions (LaO⁺ and CeO⁺) by the ICP ion source under the low-power operation. Production efficiency of oxide signals for La and Ce was remarkably enhanced, i.e., > 2,000,000 times the level obtained by the conventional ICP power (1.35 kW). Residual signal intensity of La⁺ signal was almost the same level as the instrumental background. The overall contribution of isobaric ¹³⁸La and ¹³⁸Ce to ¹³⁸Ba signals were 0.02% and 0.1%, respectively, even with the presence of x 10,000 times higher concentration of La and Ce. The data obtained here demonstrate that the level of the isobaric interferences by ¹³⁸La, ¹³⁶Ce, and ¹³⁸Ce signals produced by the low-power ionisation was negligible within the analytical precision achieved in this study (∼1%). It should be noted that the analytical sensitivity for Ba obtained by the low-power ICP remains almost 85% of the level achieved by the conventional ICP power. This is very promising because the present technique can be applied to the laser ablation sampling technique which requires high sensitivity without chemical separation or purification procedures. (author)

[en] The application of mass spectrometry to high temperature chemistry is reviewed. As a blanket material for fusion reactors, the behavior of lithium has been investigated by using mass analysers. The enthalpies of the chemical reactions of metallic lithium were obtained. The enthalpies of isomolecular exchange reactions and the derived atomization energies of LiD, Li₂D and Li₂D₂ were also obtained by mass spectrometry. The thermomechanical character of lithium oxide was studied. The vaporization behaviors of LiCrO₂ and Li₅FeO₄ were studied with a quadrupole mass analyser. The vaporization of cobalt from nickel alloy was studied. The evaporated ions were analysed with a mass analyser. The measurement of the vaporized molecules of metals and fused silicate was made by mass spectrometry. The activities of Fe-V system were determined by measuring the ion current ratio. The activities of Fe-V-Cr system were also obtained. The vapor pressure of phosphor from Fe-P alloys can be measured. The activity coefficients and interaction parameters for the dilute solutions of elements, such as Mn, Al, Cu, Cr, Co, Ni, Si, Ti, V, B, Zr, Mo, C, S, and P, dissolved in liquid iron are shown in a table. The activities of NaCl-KCl system were derived by measuring the ion current ratio and by monomer-dimer method. (Kato, T.)

[en] The vapor pressure of lithium monoxide (Li₂O) has been obtained by high temperature mass spectrometry. The partial pressures of Li, O₂ and Li₂O gaseous molecules have been determined experimentally and several thermodynamic data for the reaction (1) LiO(s) = 2Li(g) + 1/2O₂ and for the reaction (2) LiO(s) = Li₂(g) have been calculated. The third law enthalpy ΔH₀⁰ obtained for the reaction (1) is 909 +- 4 kjoule mole^-1, being in good agreement with published data. The minor vapor species such as LiO, Li₃O and Li₂O₂ were also detected. A compatibility investigation has been undertaken using Knudsen effusion cells fabricated from various refractory metals. The order of oxidation of refractory with Li₂O has been determined as follows, Pt < Ni < Ta < Mo=Nb. (author)

[en] The quadrupole type mass spectrometer system for the precise determination of ²³⁵U isotope ratio of UF₆ has been developed. Fundamental performances, such as inlet and evacuation characteristics, resolution, relative sensitivity, pattern coefficients, isotope ion current detection characteristics were measured and examined carefully on this quadrupole type mass spectrometer for UF₆. The operational stability of this quadrupole type mass spectrometer was good. ²³⁵U and ²³⁸U isotope peak was resolved perfectly. Secondary electron multiplier tube was effective for rapid measuring low ion current with high efficiency, but it had about 3% systematic error on determination of ²³⁵U isotope ratio. It was able to correct this error easily by calibration with standard sample. Results of the performance tests were good. ²³⁵U isotope ratio measurements were carried out by use of many UF₆ standard samples. The precision and the accuracy of the measurements were less than +-0.3% under appropriate operating conditions attained. The time required for measuring one sample was less than five minutes. (author)

[en] Measurements of relative ion production yields in the Penning and dissociative ionizations of methane molecules on impact of metastable helium atoms have been carried out using a new crossed-beam apparatus, ''Perfectron''. Due to the perfect focusing property of the perfectron, the total ion yield as well as differential ion yield of each reaction channel can be measured. Though the measurement is at present only preliminary and no attempt is made to discriminate between 2¹S and 2³S states in the primary helium beam, obtained spectra are in good agreement with those of Cermak et. al. and of Herce et. al. in the measurement of total ion yields. The CH₃⁺ ions are most abundant in contrast with electron impact where the parent CH₄⁺ ions predominate. On the other hand, in the measurement of differential ion yields at 0⁰ with respect to the methane beam, the parent CH₄⁺ ions slightly predominate over the fragment CH₃⁺ ions. (author)

[en] About fifteen years have elapsed since the secondary ion mass spectrometer (SIMS) has been developed. However, it may be said that the spectrometers have not entered the practical working stage till Anderson employed O₂⁺ and O^- as primary ions. Secondary ion intensity increases and becomes stable even in the case of using Ar⁺ as the primary ions if the atmosphere is composed of oxygen. In the paper, first, the interaction of oxygen with solid surfaces and the secondary ion emission from the surface, and next, the secondary ion emission from the surface adsorbing oxygen are described. The interaction may be divided into four processes: adsorption and incorporation, desorption by sputtering, recoil implantation, and implantation. The effects of introducing oxygen into a SIMS are the upgrading of sensitivity (and accuracy), the reduction of relative sensitivity difference, the improvement of analysis in the direction of depth, the decrease of interfering lines due to compound ions, and the extension of application to quantitative analysis. Though there are many proposals to explain the mechanism of emitting secondary ions in a SIMS, unified explanation can not yet be obtained. For the mechanism of emitting secondary ions in which oxygen takes part, work function model, bond breaking model, band model, surface polarization model, etc. have been proposed so far. It is considered that the clarification of the mechanism of emitting secondary ions due to chemical process is specifically indispensable for the practical quantifying in a SIMS. (Wakatsuki, Y.)

[en] A specially designed retarding field energy analyzer has been set in the front of a quadrupole mass filter for studying the energy distribution of thermal ion emitted from a hot metal surface. The distribution curve and its derivative are obtained by the technique of electrical differentiation of the retarding voltage curve in which a small sinusoidal modulation voltage is applied to the two retarding grids in a method similar to Auger electron spectroscopy with a four-grid low energy electron diffraction optics. The effects of frequency and amplitude of the modulation voltage on fundamental and second harmonic components being proportional to the energy distribution function and its derivative have been investigated. The results have been applied to study the energy distributions of Na⁺, K⁺ and Rb⁺ thermal ions emitted from a tungsten ribbon. (author)