[en] Inductively coupled plasma mass spectrometry (ICP-MS) is applied to geological standard rocks for the determination of Y, lanthanoids (Ln's), Th and U. Internal standardization is employed for the precise measurement: Rh for Y, In and Tl for Ln's, Bi for Th and U. For Ln's, linear interpolation correction is used. Our ICP-MS data agree with the recommended values within 10% for most samples. Their chondrite-normalized Ln abundance patterns are smooth, suggesting that our ICP-MS data are highly accurate and can be used for discussing detailed abundances of Ln's. The Y, Th and U data are as precise as the Ln data. The simultaneous and precise determination of Ln's, Th and U enable us to extend the geochemical discussion in better detail than before. (author)

[en] A spectral fitting method is described to analyze the ICP-AE spectrum of a crude rare-earth chloride obtained from a monazite ore. Each window for a rare-earth element (width, 1 nm; 400 data) was successively analyzed using some developed software. The linear additivity of observed reference spectra of rare-earth elements in a spectrum database was assumed to synthesize a simulated spectrum, and differences between the simulated spectrum and an observed spectrum were minimized by a least-squares method which varies linear coefficients. Consequently, determined rare-earth elements (mass% of total rare-earth) were Y(0.42%), La(23.7%), Ce(45.5%), Pr(5.38%), Nd(19.8%), Sm(3.60%), Eu(0.011%), Gd(1.17%), Tb(0.077%), Dy(0.26%), Ho(0.032%), Er(0.029%) and Yb(0.005%). Tm and Lu could not be determined due to weak line intensities. It took less than 2 min to analyze each window, when a personal computer equipped with an 80486 CPU was used. The obtained analytical results agreed well with those obtained by isotachophoresis-particle induced X-ray emission, confirming the utility of this method for such samples with heavy spectrum interference. (author)

[en] The kinetics of the complexation reaction of zirconium(IV) and hafnium(IV) with Semixylenol Orange (H₄L) have been studied spectrophotometrically by means of a stopped-flow technique. The rate of formation of the complex is expressed as d[MHL⁺]/dt=k₁[M⁴⁺][H₅L⁺][H⁺]^-2+k₂[M⁴⁺][H₅L⁺][H⁺]^-3-k₃[MHL⁺][H⁺]-k₄[MHL⁺][H⁺]² for both metal ions (M⁴⁺). With values of k₁ and k₂, assuming a dissociative interchange mechanism for the first two reaction paths in this rate equation, the rate constants of the loss of coordinated water molecules at MOH³⁺ and M(OH)₂²⁺ were estimated. With these rate constants, the γ parameters for both metal ions, which describe the acceleration effect of the bound ligand A (A=OH^- in this study) on the water exchange rate at MA, were also estimated. With the same parameter, some possibilities to design a new kinetic-catalytic method of analysis based on ligand-substitution reactions involving zirconium(IV) were proposed. (author)

[en] The extraction equilibria of molybdenum (VI) with several alkylated 8-quinolinol derivatives (HQ): 2-methyl-5-octyl-oxymethyl-8-quinolinol (HMO₈Q), 5-octyloxymethyl-8-quinolinol (HO₈Q), and 5-(4-nitrophenylazo)-7-(4-ethyl-1-methyloctyl)-8-quinolinol (HNEQ) have been investigated. Molybdenum(VI) was completely extracted with a 0.01 M extractant in chloroform from an aqueous phase at 1 M (1 M=1 mol dm^-3) HCl-pH 5 for HMO₈Q, 2 M HCl-pH 6 for HO₈Q and 4 M HCl-pH 5 for HNEQ. The extraction constants, log K_ex(=[MoO₂(Q)₂]_org/[MoO₄^2-][H⁺]²[HQ]_org², are 17.72±0.06(HO₈Q-CHCl₃), 14.90±0.07(HMO₈Q-CHCl₃), 17.00±0.07(HNEQ-CCl₄) and 17.18±0.08(HO₈Q-CCl₄) at 25degC. The molybdenum(VI)-HQ complexes, except the HO₈Q complex in an organic phase could be easily stripped with an aqueous ammonia solution. Molybdenum(VI) was selectively separated with alkylated 8-quinolinol derivatives from many metal ions, such as iron(III), cobalt(II), nickel(II), copper(II), zinc(II) and gallium(III). (author)

[en] The distribution behavior of ion associates of the tetraiodobismate(III) anion, BiI₄^-, with eight quaternary ammonium cations between a chloroform and an aqueous phase was examined, and the extraction constants (log K_ex) were determined. The extractability with long-chain alkyltrimethylammonium cations (group I) is greater than that with symmetrical tetraalkylammonium cations (group II). The contributions of a methylene group in the cations of groups I and II to log K_ex were found to be about 0.54 and about 0.40 on the average, respectively. From the extraction constants obtained, a highly sensitive extraction-spectrophotometric method of bismuth was developed. (author)

[en] Traces of Co, Cu, Ni, Th and U in high-purity zinc metal were determined by inductively coupled plasma mass spectrometry (ICP-MS) in combination with flow-injection (FI) on-line matrix separation (FI-ICP-MS). The anion-exchange separation method of an HCl system was applied to the separation of Ni, Co, Cu, Th and U from zinc matrix. The matrix element, zinc, was adsorbed on an anion-exchange (BIO·RAD AG1-X8) mini-column (2.0 mm i.d. x 300 mm bed length), while the analytes were directly introduced into the ICP-MS. The following detection limits (in ng g^-1) were obtained: Ni, 3.1; Co, 1.2; Cu, 4.0; Th, 0.12 and U, 0.48. The reproducibility has proved to be satisfactory with a relative standard deviation of less than 5% (at the 10 ng ml^-1 level, n=3). The method was successfully applied to determining trace impurities in three 6 and 7 nines grade of high-purity zinc metals and in three standard reference materials of high-purity zinc metal samples (from NIST). (author)

No abstract available

[en] The X-ray power dependence of the charge-up shift of a photoelectron line was examined for metal films insulated from a spectrometer. As the X-ray power increased, the observed line position shifted to a higher binding energy, and approached an asymptotic value. This charge-up behavior was treated based on the balance between the photoelectron emission from the sample surface and electron injection from an aluminum window of the X-ray source and from other electron sources. It was concluded that, for insulated metals, the vacuum level of the sample is aligned to that of the spectrometer when the X-ray power is extrapolated to zero, i.e., the magnitude of the charge-up is equal to zero. The work function of the spectrometer was successfully determined with samples having a known work function. A new method to obtain the binding energy relative to the vacuum level for insulators is proposed. (author)

[en] A column filled with Amberlite XAD-1180 resin was examined in order to test its suitability for extracting inorganic complexes of Cu, Cd, Pb, Bi, Ni, Fe, Mn and Co from sulfuric, nitric or hydrochloric acid solutions containing iodide, thiocyanate or their mixtures. The proposed procedure was applied to the determination of Cu, Cd, Pb and Bi in pure zinc metals by flame- or graphite furnace-atomic absorption spectrometry with good results, such as recoveries ≥95%, relative standard deviations ≤6% (n=10) and detection limits ≤0.200 μg cm^-3. (author)

[en] By detecting characteristic X-rays excited during a RHEED (reflection high energy electron diffraction) experiment, a highly sensitive measurement of the adsorbate is possible if the X-ray detector is placed at the critical angle (θ_c) corresponding to the total reflection of the X-rays. Furthermore, by measuring the glancing angle (θ_g) dependence, it is possible to analyze the depth distribution of the composition at the surface. The resolution in the depth direction is about 1 ML. By applying these methods to studying the epitaxy of metals (Ag, Au, Sn, Ga and In) on Si(111)-n x m-M surface structures (metal-induced Si(111) reconstructed surface structures), new growth modes were observed, such as the substitution-atom growth mode, the floating-atom growth mode and some complex growth modes. (author)