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Volume 49, Issue 2
Displaying 1-9 of 9 articles from this issue
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Review
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Akiyo YAMAUCHI, Takashi HAYASHITAArticle type: Review
2000 Volume 49 Issue 2 Pages 75-89
Published: 2000
Released on J-STAGE: June 29, 2001
JOURNAL FREE ACCESSThe recent developments of metal-ion probes based on photosignal transduction are reviewed in relation to their molecular design and response function. The metal-ion probes are classified into two types according to their design concepts: one is “molecular built-up” probes, in which ion recognition is performed by a single molecular receptor function; the other is “molecular assembled” probes, which are based on a supramolecular interaction derived from plural receptor molecules. For these probes, the principal mechanisms of photosignal transduction upon metal-ion recognition are summarized and their applications to metal ion sensing are discussed.View full abstractDownload PDF (928K)
Research Papers
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Haizhou WU, Noriyuki WATANABE, Ryoichi TSUKAHARA, Takao ITOH, Yohichi ...Article type: Research Papers
2000 Volume 49 Issue 2 Pages 91-97
Published: 2000
Released on J-STAGE: June 29, 2001
JOURNAL FREE ACCESSIt is very difficult to accurately quantify trace rare-earth elements(REE) in ultra-pure rare-earth compounds by a single analysis method, such as ICP-AES, ICP-MS or electrothermal vaporization(ETV)/ICP-MS. We have developed a highly sensitive and efficient method by coupling the advantages of HPLC. ETV and ICP-MS. HPLC eliminated problems caused by matrix and severe overlapping of oxides and hydroxides peaks coming from the main component observed in ICP-MS. ETV greatly reduced the interference from additives contained in the eluent of HPLC, and provided an efficient introduction method for ICP-MS. The detection limits of other REE in pure Gd2O3 were 0.07∼2ng/g Gd. The method is applicable to analyses for 7∼8N pure metal and compounds.View full abstractDownload PDF (428K) -
Shang-Qian Wu, Tetsuya KIMISHIMA, Hiroshi MASUSAKI, Hiroaki KUZE, Nobu ...Article type: Research Papers
2000 Volume 49 Issue 2 Pages 99-104
Published: 2000
Released on J-STAGE: June 29, 2001
JOURNAL FREE ACCESSThe amount of trace moisture is precisely determined in N2 and HCl gases by means of near-infrared diode-laser absorption spectroscopy. As an optical source, we use a near-infrared InGaAsP distributed-feedback diode laser which operates at room temperature. A multi-pass sample cell designed for corrosive gases is employed to enhance molecular absorption. For the purpose of reducing the etalon noise that is usually encountered in multi-pass absorption spectroscopy, we adjust the base path length in accordance with the bandwidth of a molecular spectral line so that the etalon frequency does not critically overlap with that of the molecular spectrum. The remaining noise is further reduced by applying multi-stage smoothing. Trace moisture content as small as 2.3ppb is detected with a 20-m absorption length.View full abstractDownload PDF (419K) -
Tetsuya SATO, Misa KATO, Katsunori KIMIJIMA, Masaki OKUYAMA, Kiyoshi C ...Article type: Research Papers
2000 Volume 49 Issue 2 Pages 105-110
Published: 2000
Released on J-STAGE: June 29, 2001
JOURNAL FREE ACCESSA metastable transfer emission spectroscopy(MTES) combined with a tungsten coil atomizer was carried out for the sensitive determination of cadmium. Pulse atomization induced by a capacitor discharge to the coil atomizer produced a condensed vapour, which was transported and mixed with active nitrogen in a metastable state produced by a microwave discharge. A high sensitivity was obtained from the emission of cadmium by this system. Some new spectra were observed by MTES. Five μl of a cadmium solution acidified with nitric acid was deposited on the coil atomizer. A detection limit of less than 5pg was obtained at a wavelength of 326.1nm. This system is more sensitive by a factor of six than a system using a Ta boat. The linearity range of a calibration curve was from 5 to 200pg Cd, beyond which the emission signal intensity was saturated. The saturation is likely to be controlled by the density of metastable nitrogen molecules existing in the excitation region.View full abstractDownload PDF (383K) -
Shan JI, Tomoki YABUTANI, Akihide ITOH, Koichi CHIBA, Hiroki HARAGUCHIArticle type: Research Papers
2000 Volume 49 Issue 2 Pages 111-119
Published: 2000
Released on J-STAGE: June 29, 2001
JOURNAL FREE ACCESSThe distributions of major-to-ultratrace elements into natural salt from coastal seawater in a salt-preparation process were investigated by ICP-AES(inductively coupled plasma atomic emission spectrometry) and ICP-MS(inductively coupled plasma mass spectrometry) with preconcentration using a chelating resin. The coastal seawater samples were collected off-shore near to the Nie coast, where Agehama-made salt is produced by a classical Agehama method. Natural salt was produced from original coastal seawater in the laboratory in a similar manner to the Agehama method. First, the seawater samples were filtered with a membrane filter(pore size of 0.45μm), and the elements in the dissolved fraction(filtrate) and in the particulate fraction(particulate on the filter) were determined by ICP-AES and ICP-MS. The analytical results for seawater indicate that alkali elements, alkaline earth elements, and oxoanion-forming elements (V, Mo, W, U) were dominantly in the dissolved fraction, while other elements such as Al, Fe, Pb and rare earth elements were mostly in the particulate fraction. The elements in laboratory-made salt and Agehama-made salt were also determined by ICP-AES and ICP-MS after dissolving them in a 0.1M HNO3 solution. Although the concentrations of trace elements in laboratory-made salt and Agehama-made salt were almost at the same levels for 27 elements among 34 elements within a factor between ca.1/5 and 5, Ba, Mn, Cd and Pb in Agehama-made salt were much higher (8-30 fold) in concentration than those in the laboratory-made salt. Based on the experimental results mentioned above, the distributions of major-to-ultratrace elements into natural salt from seawater were discussed, taking into consideration the preparation process of natural salt.View full abstractDownload PDF (650K)
Technical Papers
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Michio ZENKI, Yoshihiko NAKAKITA, Aika KOMATSU, Takashi YOKOYAMAArticle type: Technical Paper
2000 Volume 49 Issue 2 Pages 121-124
Published: 2000
Released on J-STAGE: June 29, 2001
JOURNAL FREE ACCESSThe use of a closed-loop system in flow-injection analysis(FIA) allows for the recycling of reagents which are present in excess. Strong acids and bases are determined by injection into a continually circulated buffer solution containing an acid-base indicator. Neutralization occurs in the sample zone and discoloration of an indicator is monitored by spectrophotometry. Passing though the flow cell, the resulting solution is then buffered and returns to the reservoir. A typical aqueous reservoir solution contained 0.1M acetate buffer and 1.5×10-4M Methyl Orange. This solution was circulated at a flow rate of 2.5ml/min. Sample(acid or base) aliquots of 2μl were introduced into the stream and the differential absorbances were monitored at 530nm. The calibration curve of samples by this method showed good linearity over a range of 0.1-5M. Acids(HCl, HNO3, H2SO4, and oxalic acid) and bases(NaOH, KOH and NH3) gave the same slope of the calibration curve, respectively. Although a slight gradual increase in the baseline shift could not be avoided, it allowed 500 repetitive determinations of 1M HCl or NaOH with the same 100ml of circulating 0.1M acetate buffer solution.View full abstractDownload PDF (259K)
Notes
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Tomokazu TANAKA, Kenji FURUHASHI, Daisuke MATSUO, Masataka HIRAIDEArticle type: Note
2000 Volume 49 Issue 2 Pages 125-127
Published: 2000
Released on J-STAGE: June 29, 2001
JOURNAL FREE ACCESSA combined method of electrothermal vaporization and ICP-MS was studied for microtrace analysis. A 5μl volume of a sample was placed on a tungsten filament(0.2mm in diam.×45mm) and desolvated electrothermally. Arsenic in the residue was then vaporized by increasing the temperature of the filament to 2450°C with the aid of a capacitor(0.22F) and then carried in an argon stream to an ICP torch. The filament was used repeatedly at least 100 times. The relative standard deviation(n=10) for signal intensities of 15pg As was ca. 10%, with an absolute detection limit(3σ) of 1pg. The proposed method was applied to the determination of arsenic in a certified reference human hair sample. The analytical results obtained for the sample(decomposed with 14M nitric acid and hydrogen peroxide) were 0.35±0.03μg g-1, which almost coincided with the certified values(0.31±0.02μg g-1).View full abstractDownload PDF (183K)
Digest of Doctoral Dissertation
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Yoshio MACHIDAArticle type: Digest of Doctoral Dissertation
2000 Volume 49 Issue 2 Pages 129-130
Published: 2000
Released on J-STAGE: June 29, 2001
JOURNAL FREE ACCESSEnantiomers often differ in pharmacological activity. Usually, only one of the various isomers fully contributes to therapeutic action, and the others do not. The separation of enantiomers is a subject of great interest because the antipode of a chiral drug is regarded as being an impurity from the view-point of quality control. Recently, chromatographic techniques, especially high-performance liquid chromatography with chiral stationary phases(CSPs), have been extensively used to achieve direct enantiomer separation. Various kinds of CSPs are commercially available. In this study, (1)the author designed and prepared novel CSPs(CSP-18C6I, II, III) which immobilized chiral crown ether ((+)-18-crown-6 tetracarboxylic acid). Then, the CSPs(18C6 series) were applied to the enantiomeric separation of amino acids, aminoalcohols and some hydrophobic amino compounds, which were them enantioseparated successfully. (2)Studies of the chiral-recognition mechanism of 18C6H4 using NMR and crystalline X-rays were performed and explained. (3)A modification(the addition of metal cations or cyclodextrin) of the mobile phase used in Crownpak CR(+), where hydrophobic chiral crown ether was dynamically coated on an ODS column, was investigated. A fast analysis of hydrophobic amino compounds was accomplished using this method.View full abstractDownload PDF (138K) -
Yoshihiro MORIArticle type: Digest of Doctoral Dissertation
2000 Volume 49 Issue 2 Pages 131-132
Published: 2000
Released on J-STAGE: June 29, 2001
JOURNAL FREE ACCESSMetallic impurities on the surface of semiconductor wafers deteriorate the electrical properties of LSI devices. In recent years, total reflection X-ray fluorescence(TXRF) spectrometry has come into wide use in semiconductor industry for the analysis of metal impurities. In TXRF analysis, the properties of a standard sample, especially the depth distribution of the analyte, are significant for accurate quantification. First, requirements for standard samples are discussed. Next, a study of metal adsorption in ammoniac hydrogen peroxide cleaning solution through equilibrium analysis is considered. It has been found that the properties of the wafers, on which metals are adsorbed in the solution, are suitable for standard samples of TXRF. This method was named “immersion in alkaline hydrogen peroxide(IAP).” The depth distribution of analyte on IAP wafers was evaluated by fitting angle scan data. After carrying out the above-mentioned studies, cross-check experiments between TXRF and other methods at a level of 1012 atoms cm-2 were conducted by using the IAP standard samples. The study clarified that the IAP standard samples are suitable for crosscheck experiments. Finally, the accuracy of TXRF below a level of 1011 atoms cm-2 was examined. With IAP standard samples, the determination values of TXRF agreed with those of AAS with an accuracy of 20%.View full abstractDownload PDF (134K)
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