Analytical Sciences
Online ISSN : 1348-2246
Print ISSN : 0910-6340
ISSN-L : 0910-6340
Volume 12 , Issue 2
Showing 1-40 articles out of 40 articles from the selected issue
  • J. KARPINSKA, B. STARCZEWSKA, H. PUZANOWSKA-TARASIEWICZ
    1996 Volume 12 Issue 2 Pages 161-170
    Published: April 10, 1996
    Released: July 04, 2006
    JOURNALS FREE ACCESS
    Phenothiazine derivatives substituted in the 2 and 10 positions belong to a big group of tricyclic aromatic compounds. They are in extensive use in psychiatry as tranquilizers and neuroleptics. Due to their characteristic structure they exhibit many valuable analytical properties. They are easily oxidized in an acidic medium while generating color products. They also react with some thiocyanate and halide complexes of metals as well as some organic compounds, and form well-defined ion-association complexes. The properties mentioned above are the basis for utilizing the phenothiazine derivatives as reagents for chemical analysis. The physical and chemical properties of 2, 10-disubstituted phenothiazine derivatives are described in the presented paper in detail. The paper is divided into seven parts. The first chapter presents the physical properties of the phenothiazine derivatives, such as their physical state, thermal stability and solubility. The next part of the paper is devoted to the spectral properties of 2, 10-disubstituted phenothiazine derivatives. The influence of the type of substituents on the intensity and shape of the UV and fluorescence spectra of phenothiazine derivatives are discussed. Chapters 4 and 5 show the run and the mechanism of phenothiazine derivatives oxidation, their electrochemical properties and the analytical aspects of the described processes. Chapter 6 of the present paper is devoted to the complexing abilities of the phenothiazine derivatives. The paper is based on a review of the chemical literature up to 1995. A short specification of the analytical methods utilizing the physical and chemical properties of the phenothiazine derivatives is also included.
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  • Kazuaki KAKEHI, Atsuko HIROSE, Toshiaki TAMAI, Atsushi TAGA, Susumu HO ...
    1996 Volume 12 Issue 2 Pages 171-176
    Published: April 10, 1996
    Released: July 04, 2006
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    A few colominic acid preparations and N-acetylneuraminic acid (NANA) oligomers derived thereof were analyzed by capillary zone electrophoresis with low-wavelength UV detection. Colominic acid homologues having degrees of polymerization (d.p.s) up to ca. 30 were separated to the baseline level, and homologues having a d.p.s of 30-40 were discriminated from each other using a 100cm capillary (50μm i.d.) and a 25mM phosphate buffer containing SDS to a concentration of 100mM as the carrier. A colominic acid preparation was hydrolyzed by a dilute acid (10mM HCl), an acidic buffer (50mM acetate buffer, pH 4.8) and neuraminidase from Arthrobacter ureafaciens; the products were then analyzed under the established conditions. The information from the obtained results will be useful for estimating NANA oligomers and polymers having a specified d.p.s, and for investigating the biosynthesis and metabolism of glycoconjugates containing these homologous oligosaccharides.
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  • Jing-yi HE, Akimasa SHIBUKAWA, Min ZENG, Shizuya AMANE, Takeshi SAWADA ...
    1996 Volume 12 Issue 2 Pages 177-181
    Published: April 10, 1996
    Released: July 04, 2006
    JOURNALS FREE ACCESS
    The on-capillary sample enrichment technique was developed to improve the sensitivity of UV-detection in capillary electrophoresis (CE). The enrichment was achieved in a preconcentration zone (zone length 2mm) filled with the packing material used for HPLC, which is fixed by an inner frit near to the inlet of the capillary. The feasibility of this technique was demonstrated by chiral separation of a low concentration of verapamil (VER, a calcium channel blocker) enantiomers. The preconcentration procedure involves initial conditioning of the capillary, hydrodynamic sample introduction, washing of adsorbed VER, and its transfer to the capillary. Enriched VER was separated into enantiomers using a chiral selector (25mM trimethyl-β-CD) dissolved in the run buffer (pH 2.5). The detection limit was 5nM, about 200-times lower than that without preconcentration. The detection response indicated good linearity against the concentration of VER over the 10-100nM range for each enantiomer (r>0.999). The present CE system was applied to determine the unbound concentration of VER enantiomers in human plasma after ultrafiltration.
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  • Gong-Min CAO, Tadao HOSHINO
    1996 Volume 12 Issue 2 Pages 183-188
    Published: April 10, 1996
    Released: July 04, 2006
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    A new method of high-performance liquid chromatographic three-potential electrochemical detection was developed and applied for determining DA, DOPA, NE, E, 3MT, DOPAC, HVA, MHPG, DEP, 5HT and 5HIAA in rat-brain tissue. The proposed method employed a coulometric electrochemical detector coupled with a conditioning cell and a dualelectrode analytic cell. Three individual potentials were applied to the electrodes in order to oxidize-reduce the analytes. This detection system could effectively avoid interfering substance peaks, and could accurately quantify eleven components of catecholamines and serotonin as well as metabolites. The present method showed normal linearity with quantity injection of the standards; the detection limit was 0.17-1.22pg for all analytes of interest. In a measurement of neuroamines in rat-brain, the recovery of all target components averaged 74.5%.
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  • Kazumi SASAMOT, Tamano USHIJIMA, Mikihiko SAITO, Yosuke OHKURA
    1996 Volume 12 Issue 2 Pages 189-193
    Published: April 10, 1996
    Released: July 04, 2006
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    A new coumarin-based amine, 4-aminomethyl-6, 7-dimethoxycoumarin, was synthesized as a precolumn fluorescence derivatization reagent for carboxylic acids. The derivatization using the amine in a two-phase medium of water and ethyl acetate was examined. The two-phase derivatization method with the amine was found to be of value since it allows simple and rapid HPLC assays of carboxylic acids with a reasonable sensitivity and reparability. The detection limit was determined to be 20-50fmol per 10μl injection volume at a signal-to-noise ratio of 3 under partially optimized conditions. The method was also applied to the assay of fatty acids in human serum.
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  • Jin-Chun WOO, Dong-Min MOON, Hiroshi KAWAGUCHI
    1996 Volume 12 Issue 2 Pages 195-200
    Published: April 10, 1996
    Released: July 04, 2006
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    A discharge ionization detector for gas chromatography was designed and optimized for the analysis of inert gas. A wire-mesh suppression electrode was placed between the discharge and collector electrodes so as to enhance the signal-to-noise ratio. The sensitivities obtained during an atmospheric helium discharge were about 1000-times higher than those obtained under a reduced-pressure discharge. There was no significant variation in the signal response when changing the applied potential to the suppression electrode. In contrast, when the size of the hole in the suppression electrode was increased, the signal response was increased. These facts suggest that the eluent gas is ionized by photons or metastable helium atoms, but not by such charged particles as helium ions or electrons. Under the optimum operating conditions, the noise and background levels were 5×10-13 A and 8×10-9 A, respectively. Detection limits of 0.2-2pg/s were obtained depending on the determined gases.
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  • C. F. WANG, M. F. HUANG, E. E. CHANG, P. C. CHIANG
    1996 Volume 12 Issue 2 Pages 201-207
    Published: April 10, 1996
    Released: July 04, 2006
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    Closed vessel acid digestion methods, especially the microwave digestion, have been investigated for elemental analysis of airborne particulates collected by glass fiber filter and analyzed by ICP-AES. A two-step digestion procedure was examined; it included the digestion of airborne particulates with HNO3+HClO4 in the first step and the addition of HF after removal from the intact filter membrane in the second step. Both the NIST Standard Reference Material 1648 urban particulate matter and real samples were employed to assess the capabilities of the suggested methods throughout the QA/QC programs. It was found that the two-step method is an appropriate pretreatment procedure for multi-element analysis by ICP-AES. The importance of evaporation after the digestion and of the substitution of H3BO3 addition for evaporation process are discussed. Both evaporation and H3BO3 addition processes after the digestion may effectively reduce the matrix effect on the suppression of the analyte elements. A comparison between the conventional pressure bomb and microwave digestion methods was performed using real samples.
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  • Kunihiko AKATSUKA, Takunori KATOH, Naoki NOBUYAMA, Takayoshi OKANAKA, ...
    1996 Volume 12 Issue 2 Pages 209-213
    Published: April 10, 1996
    Released: July 04, 2006
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    An octadecylsilylsilica (C18) column dynamically coated with methyltricaprylylammonium chloride (C18-Aliquat 336) was examined for the preconcentration of trace amounts of Zn in water samples. Zinc was quantitatively retained on the column from an HCl solution at between 0.5 and 3mol dm-3, or seawater acidified with HCl, ranging from 0.5 to 1.0mol dm-3. The retention capacity of the C18-Aliquat 336 for zinc was about 50μmol g-1 from a 1mol dm-3 HCl solution. The Zn retained on the column was completely eluted with 3.5ml of 0.1mol dm-3 nitric acid, and was directly determined by graphite-furnace atomic absorption spectrometry. The precision and accuracy of the present method were demonstrated by analyzing certified reference materials, such as Coastal Seawater (CASS-2) and Riverine Water (SLRS-3). The total procedural blank was 1.9±0.4ng for Zn. The detection limit (3σ of the blanks) was 2.4ng dm-3 for Zn based on a 125-fold concentration of a 500-ml sample.
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  • Hui LI, Hiromichi NAGASAWA, Kazuko MATSUMOTO
    1996 Volume 12 Issue 2 Pages 215-218
    Published: April 10, 1996
    Released: July 04, 2006
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    The sensitivity of organomercury in organic solutions has been found to be enhanced by applying 15μl of an ethanol solution of Pd(acac)2 (500μg Pd ml-1, acac is acetylacetonate) to a graphite-furnace, which is then heated to make a Pd coating on the furnace. After this treatment, an ethanol solution of the sample is injected to the furnace and measured. With this method, the detection limit of organomercury was found to be 0.25ng. In a slightly different way, in which 2ml of an ethanol solution of PdCl2(PhCN)2 (1000μg Pd ml-1) was added as a matrix modifier to 3ml of an ethanol solution of organoselenium, selenium was determined with a detection limit of 0.12ng. These methods can be successfully applied to the determinations of organomercury and organoselenium in an extract solution of a dolphin liver.
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  • Shizuko AMBE, Masako IWAMOTO, Haruka MAEDA, Fumitoshi AMBE
    1996 Volume 12 Issue 2 Pages 219-224
    Published: April 10, 1996
    Released: July 04, 2006
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    The transport of Au(III) and 19 other metal ions through a tributyl phosphate (TBP)-decalin membrane supported on a microporous polytetrafluoroethylene sheet was studied in order to establish a procedure for removing Au(III) ions from acid solutions of a gold target irradiated by high-energy heavy ions, leaving a multitracer solution in a carrier-and salt-free state. Distilled water was used as a stripping agent. A feed solution of 3mol dm-3 HCl gave the highest transport rate in the 0.1-8mol dm-3 HCl range. The transport of carrier-free radioisotopes of Sc, Fe, Zr, Nb, Te, and Hf was observed for 8mol dm-3 HCl and that of Fe, Zr, Nb, and Te for 5 and 6mol dm-3 HCl, while their transport was not detected for 0.1 and 1mol dm-3 HCl feed solutions and was small with 3mol dm-3 HCl. The 3mol dm-3 HCl solution is considered to be the best feed solution for preparing a multitracer from an Au target, because of the large transport rate of Au(III) and the negligible transport of other elements. The transport rates of Au(III) ions from 0.2-2mol dm-3 HNO3 solutions are smaller than those from 1-6mol dm-3 HCl. On the basis of these observations, a practical procedure was established for preparing a multitracer solution from a heavy-ion-irradiated Au target.
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  • Yuji SASAKI, R. CHOPPIN
    1996 Volume 12 Issue 2 Pages 225-230
    Published: April 10, 1996
    Released: July 04, 2006
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    The diamide type extractants (N, N′-dimethyl-N, N′-dihexyl-3-oxapentanediamide, DMDHOPDA, N, N′-dihexyl-3-thiopentanediamide, DHTPDA, and N, N′-dihexyl-3-oxapentanediamide, DHOPDA) were synthesized and tested for the extraction of the lanthanide and actinide elements. The elements, Eu3+, Am3+, Th4+, NpO2+ and UO22+, when extracted by DMDHOPDA, showed no pH-dependence. The relationships between log[DMDHOPDA] and log D under different ionic strengths were investigated in order to clarify the extraction reactions. The separation factor for Eu3+/Am3+ is 8.64.
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  • Qiuquan WANG, Kin-ichi TSUNODA, Hideo AKAIWA, Limin YANG, Haimin MA, Y ...
    1996 Volume 12 Issue 2 Pages 231-236
    Published: April 10, 1996
    Released: July 04, 2006
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    The extraction behavior of rare-earth elements on silica gel impregnated with petroleum sulfoxide (PSO) from an aqueous NH4SCN solution was systematically investigated. With a batch method, the distribution ratios and separation factors of rare-earth elements in this medium were determined. The composition of the extracted complex was determined by a slope analysis as being (PSO)3RE(SCN)Cl2. Through the IR spectra it was proved that the oxygen atom of the >S=O group in PSO coordinates the rare-earth element to form the extracted complex. The standard enthalpy (ΔH°RE) in the process of PSO-extraction of rare-earth elements was measured; ΔH°RE indicated that the distribution process of the rare-earth element between the PSO-silica gel stationary and NH4SCN mobile phases is an exothermic process. Moreover, the stabilities of the extracted complexes are discussed in terms of Δ(ΔG°)Ln/Y, the relative standard free energy of complex formation (ΔG°LnG°Y). The quantitative separation of yttrium from lanthanides has been achieved by this method, which was also used in an analysis for yttrium in the Jiangxi ionic-type rare-earth ores of China.
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  • Susumu KAWAKUBO, Koji KAJIHARA, Masaaki IWATSUK
    1996 Volume 12 Issue 2 Pages 237-242
    Published: April 10, 1996
    Released: July 04, 2006
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    A highly sensitive spectrophotometric FIA method is proposed for the determination of vanadium using the vanadium-catalyzed oxidation of o-phenylenediamine with bromate at pH 4.0 and 50°C in the presence of gallic acid as an activator. The same calibration graph with a linear range of 0-8μg l-1 was obtained for V(IV) and V(V) by the proposed method. The detection limit and typical sampling frequency were 4ng l-1(0.8pg) and 30 samples h-1, respectively. Iron ions of up to 5μg l-1 and humic acid of up to 3000μg l-1 were tolerable in the determination of 0.2μg l-1 of vanadium; the latter value was markedly improved compared to that with a manual-batch fluorometric method. The proposed method was successfully applied to analyses of lake, river, ground, rain and tap water samples containing vanadium down to 0.02μg l-1
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  • Takashi TOMIYASU, Hayao SAKAMOTO, Norinobu YONEHARA
    1996 Volume 12 Issue 2 Pages 243-248
    Published: April 10, 1996
    Released: July 04, 2006
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    The iron(II) catalyzed oxidation reaction of chlorpromazine with hydrogen peroxide in hydrochloric acid solution was studied kinetically by an initial-rate method. All reactions were run at constant ionic strength 0.44mol l-1 and at 30°C and followed by measuring the absorbance at 525nm of the red free radical formed. According to results of a kinetic study of the iron(II) catalyzed reaction, a mechanism is proposed which leads to the following rate equation: R0cat=[Fe(II)]0[CP][H+][H2O2]/(2.0×10-2[CP][H+]+2.2×10-4[H2O2]+1.8×10-3[H2O2][H+]+2.0[CP][H+][H2O2]). The optimal condition for iron determination by initial rate procedure was predicted using this rate equation and analytical implications of the mechanistic study are discussed.
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  • Yasunobu OHMIYA, Tatsuya SEKINE
    1996 Volume 12 Issue 2 Pages 249-254
    Published: April 10, 1996
    Released: July 04, 2006
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    The solvent extraction of silver(I) in aqueous 0.1mol dm-3 sodium nitrate solutions with 2-thenoyltrifluoroacetone (Htta) and 4-isopropyltropolone (β-isopropyltropolone, Hipt) into chloroform was studied in the absence and presence of tetrabutylammonium ions (tba+), and the results were compared. Although extraction with Htta was poor, it was very much enhanced and nearly quantitative extraction was achieved by the addition of tba+. This was assumed to be due to the fact that the complex, Ag(tta), was hydrophilic due to its hydration, but tba+Ag(tta)2-, which was extracted in the presence of tba+, was very weakly hydrated and bulkier. Both Ag(ipt) and Ag(ipt)(Hipt) were extracted; extraction with Hipt was not very effective in the absence of tba+. By the addition of tba+, the anionic complex, tba+Ag(ipt)2-, was also extracted, and nearly quantitative extraction was also achieved. Since the formation of this anionic complex is made by an exchange of ipt- with Hipt of the Ag(ipt)(Hipt) species, the enhancement of extraction was impaired by the dissociation of Hipt from the self-adduct.
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  • Anant P. ARGEKA, Ashok K. SHETTY
    1996 Volume 12 Issue 2 Pages 255-258
    Published: April 10, 1996
    Released: July 04, 2006
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    Cyanex 301 [bis(2, 4, 4-trimethylpentyl)dithiophosphinc acid] has been proposed as a selective reagent for the extractive spectrophotometric determination of copper. The molar absorptivity of Cu(II)-Cyanex 301 complex in toluene is 1.41×104l mol-1 cm-1 at 440nm. The method has been applied for the determination of copper in pharmaceutical formulations, human hair and foodstuffs.
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  • Zubi LI, Jialin WANG, Qiheng XU
    1996 Volume 12 Issue 2 Pages 259-262
    Published: April 10, 1996
    Released: July 04, 2006
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    A sensitive method for the determination of trace amounts of scandium by spectrophotometry is described, based on the formation of the ion associate between scandium(III), molybdate and Nile Blue in the presence of poly(vinyl alcohol). The molar absorptivity at 585nm is 3.59×105dm3 mol-1 cm-1. Beer′s law is obeyed over the range 0-2.0μg scandium per 25ml. Optimal conditions for the determination and the interferences from foreign ions are reported. Ten-fold amounts of rare earth elements do not interfere with the determination of scandium, except cerium. The proposed method has been applied successfully for the spectrophotometric determination of scandium in some geological samples.
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  • Takashi ISHIYAMA, Ken-ichiro ABE, Tatsuhiko TANAKA, Atsushi MIZUIKE
    1996 Volume 12 Issue 2 Pages 263-265
    Published: April 10, 1996
    Released: July 04, 2006
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    A simple, rapid and sensitive method based on catholic stripping voltammetry without preliminary separation of the copper matrix is described for the determination of lead at the μg g-1 level in copper. The sample was decomposed with nitric acid (2+1), and sodium hydroxide was added to prepare a 1M sodium nitrate electrolyte at pH 2.0. More than 35% of the lead at the ng level in a 1-cm3 aliquot of the electrolyte containing 2mg of copper was electrodeposited on a platinum anode as lead(IV) oxide at +1.6V vs. SCE in 25min. Reproducible differential pulse catholic stripping curves were obtained by scanning the potential at a rate of 50mV s-1 to +0.60V vs. SCE. The determination of 5 to 50μg g-1 of lead in copper wire was achieved with RSDs of ca. 6% (n=5-10) within 1h.
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  • Zhiqiang GAO, KOK Siong SIOW
    1996 Volume 12 Issue 2 Pages 267-271
    Published: April 10, 1996
    Released: July 04, 2006
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    A procedure for the direct determination of tin in biological samples is described. Based on the formation of the adsorptive complex of tin with 8-hydroxyquinoline (oxine), it is possible to determine subnanomolar levels of tin after a few minutes of stirred accumulation at-0.25V. The detection limits are 0.35nM (40ppt) and 70pM (8.3ppt) for 1- and 5-min accumulation periods, respectively. The standard deviation at 50nM is 1.4%. Possible interferences were investigated. This procedure was applied to determine trace amounts of tin in blood, serum and plants.
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  • Kenji HAMASE, Hiroshi NAKAMURA, Terumi NAKAJIMA
    1996 Volume 12 Issue 2 Pages 273-275
    Published: 1996
    Released: July 27, 2007
    JOURNALS FREE ACCESS
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  • Yoshihiro MORI, Kengo SHIMANOE
    1996 Volume 12 Issue 2 Pages 277-279
    Published: April 10, 1996
    Released: July 04, 2006
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  • Toru OBA, Masami KOBAYASHI, Shoichiro YOSHIDA, Tadashi WATANABE
    1996 Volume 12 Issue 2 Pages 281-284
    Published: April 10, 1996
    Released: July 04, 2006
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  • Adela RODRIGUEZ-ROMERO, Kaliyamoorthy PANNEERSELVAM, Manuel SORIANO-CA ...
    1996 Volume 12 Issue 2 Pages 285-286
    Published: April 10, 1996
    Released: July 04, 2006
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  • Koo-soon CHUNG
    1996 Volume 12 Issue 2 Pages 289
    Published: April 10, 1996
    Released: July 04, 2006
    JOURNALS FREE ACCESS
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  • Hiroshi NAKAMURA
    1996 Volume 12 Issue 2 Pages 290
    Published: April 10, 1996
    Released: July 04, 2006
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  • Ming GUO, Lu XU, Hua LI, Chang-Yu HU
    1996 Volume 12 Issue 2 Pages 291-294
    Published: April 10, 1996
    Released: July 04, 2006
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    A quantitative structure-property study has been made on the relationship between molar absorptivities (ε) of asymmetrical phosphone bisazo derivatives of chromotropic acid and their color reactions with cerium by multiple regression analysis and neural network. The new topological indices Ax1, -Ax3 suggested in our laboratory and molecular connectivity indices of 43 compounds have been calculated. The results obtained from the two methods are compared. The neural network model is superior to the regression analysis technique and gave a prediction which was sufficiently accurate to estimate the molar absorptivities of color reagents during their color reactions with cerium.
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  • Yuexia ZHANG, Teng ZHU, Guanhua YUE
    1996 Volume 12 Issue 2 Pages 295-299
    Published: April 10, 1996
    Released: July 04, 2006
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    Tin(IV) in a medium of sulfuric acid-oxalic acid with some thiazine dyes, e.g. new Methylene Blue (NMB) or Toluidine Blue (TB), at -0.60V (vs. SCE) produced a highly sensitive adsorptive complex wave. The sensitivity was increased to about 16-times higher than that without those dyes in the above-mentioned medium. The detection limit was 0.8ng/ml (6.7×10-9mol/l) Sn(IV). The existing form and the apparent stability constant (k) of these complexes, the reversibility of the electrode process, the character of adsorption and the mechanism of the electrode reaction were investigated, and a series of constants and parameters were calculated. The proposed method was applied to determine trace tin in drinking-water samples and reagents with satisfactory results.
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  • Koji MATUSAKI, Tomoki YAMAGUCHI, Yuroku YAMAMOTO
    1996 Volume 12 Issue 2 Pages 301-305
    Published: April 10, 1996
    Released: July 04, 2006
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    Boron was determined by atomic absorption spectrometry with a coated graphite furnace. Pyrolytic graphite tubes were first coated with titanium carbide, and then further coated with tungsten carbide. A mixture of nitrates of strontium and nickel and ascorbic acid was then added to a sample solution as a matrix modifier. Using this doubly coated tube, the determination of boron was successful with high sensitivity. No interference from metal nitrates and chlorides was observed. The sulfate interference could be removed by adding ammonium salt of EDTA.
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  • Hyo J. KIM, Sung K. CHOI, Kee B. LEE, Ha S. KIM, Gae H. LEE
    1996 Volume 12 Issue 2 Pages 307-310
    Published: April 10, 1996
    Released: July 04, 2006
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    A modified gas jet-enhanced sputtering device was investigated in atomic spectrometry for the analysis of solid samples. Comparisons of the calibration curve and analytical performance were made between three types of jet cofigurations. These included a six-jet configuration, a cone jet configuration, and a cylinder-jet configuration. The absorbance of Ni (232.0nm), Mn (279.5nm), Cr (357.9nm), Cu (324.7nm), Si (251.6nm) sputtered from iron and the absorbance of Ni (232.0nm) sputtered from aluminum, brass and iron were studied. The cone jet configuration showed the highest sensitivity. Sensitivities of 1% absorption for Cu, Cr, Ni, Mn, and Si, determined in the low-alloy steel under the optimum conditions, were 81, 20, 49, 57, and 79μg/g with cone-jet configuration, respectively.
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  • Tai-Ly TSO, Shih-Yi CHANG
    1996 Volume 12 Issue 2 Pages 311-319
    Published: April 10, 1996
    Released: July 04, 2006
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    Toxic air pollutants were investigated in a petrochemical industrial park in Taiwan using a movable open-path Fourier-transform infrared spectroscopy (FTIR). The results show the qualitative and quantitative analysis of emission gases from plants, and also provide the emission rates of various compounds. More than twenty compounds under usual operation were found from this industrial park. The concentration variation with time could be correlated exactly with the distances from the emission source along the wind direction. This means that by changing the measuring points the source of emission could be unambiguously identified. The point, area and line source (PAL) plume dispersion model has been applied to estimate the emission rate of either a point or an area source. The local atmospheric stability was determined by releasing an SF6 tracer. The origin of errors came mainly from the uncertainty of the source configuration and the variation of the meteorological condition. Through continuous measurement using a portable open-path Fourier transform infrared (POP-FTIR) spectrometer, the maximum value of the emission rate and the annual amount of emission could be derived. The emission rate of the measured toxic gases was derived by the model technique, and the results show that the emission amount is on the order of ten to hundred tonnes per year.
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  • Bo Un YOON, Keunchang CHO, Hasuck KIM
    1996 Volume 12 Issue 2 Pages 321-326
    Published: April 10, 1996
    Released: July 04, 2006
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    A scanning tunneling microscope (STM) has been constructed to observe the surface change of a working electrode during the electrochemical reactions in electrolyte solution. Both potentials of STM tip and substrate with respect to a reference electrode can be independently controlled by simply combining with a commercially available potentiostat and the STM. These types of apparatus are used to study the electrochemical deposition of Ag on a highly oriented pyrolytic graphite (HOPG) substrate in HClO4 solution. Before Ag deposition and after stripping the Ag film, atomic images of HOPG surface are obtained. The STM images of Ag deposit produced by cyclic voltammetric and potential pulse methods are observed. The observed STM images support the conclusion that the electrodeposition occurs according to the island growth mechanism.
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  • Kwang KIM, Young Ok PARK, Hyun Ja CHUN
    1996 Volume 12 Issue 2 Pages 327-330
    Published: April 10, 1996
    Released: July 04, 2006
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    The interaction of a corticosterone antibody and glutaraldehyde adsorbed on a Pt electrode modified with silane was examined by cyclic voltammetry. A mirror-polished Pt wire was oxidized for 10min at +1.3V vs. Ag/AgCl in 1.0M H2SO4. The oxidized Pt wire was coated with 3-aminopropyltrimethoxysilane under N2 gas for 1h at room temperature in benzene, and then modified with glutaraldehyde. The modified electrodes were tested for their electrocatalytic properties and interaction with the corticosterone antibody. The catholic peak currents (-0.4V) exhibited a reproducible linearity of the current intensity vs. the concentration of anticorticosterone.
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  • Masao SUGAWARA, Keiji OKUDE, Koji TOHDA, Yoshio UMEZAWA
    1996 Volume 12 Issue 2 Pages 331-335
    Published: April 10, 1996
    Released: July 04, 2006
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  • Hye Jin KIM, Mi Jeoung KIM, Jin Mog KIM, Geun Sig CHA
    1996 Volume 12 Issue 2 Pages 337-341
    Published: April 10, 1996
    Released: July 04, 2006
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    The feasibility of using alkaline phosphatase (ALP) as a generic label in a homogeneous type assay is examined. In the proposed ALP-based biotin-avidin mediated assay, the activity of the ALP-biotin conjugate is inhibited in the presence of the avidin-riboflavin conjugate, and the observed inhibition is reversed in an amount proportional to the concentration of riboflavin binding protein (RBP) added. The ALP activity of the mixture is re-inhibited upon additions of free analyte riboflavin, to an extent proportional to the concentration of riboflavin added to the assay mixture. An avidin-riboflavin conjugate with a desired inhibitory effect is prepared by protecting the binding-site of avidin with 2-iminobiotin during the conjugation reaction at pH 6.5. The catalytic activity of ALP, conjugated with biotin, is inhibited to a significant degree (up to 86%) by the binding of the avidin-riboflavin conjugate, and is fully recovered upon additions of RBP.
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  • Kiyoko TAKAMURA, Tetsuo FUSE, Fumiyo KUSU
    1996 Volume 12 Issue 2 Pages 343-347
    Published: April 10, 1996
    Released: July 04, 2006
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    A new method was developed using flow injection analysis (FIA) with amperometric detection for determining the activity of esterases, such as lipase and cholinesterase. Such esterases catalyze hydrolysis reactions of the substrate esters to release constituent acids. The released acids were determined based on current height of the reduction prepeak of quinone. Olive oil, as a substrate, produces higher fatty acids through lipase enzyme reaction. Benzoylcholine or acetylcholine, as a substrate, produces benzoic acid or acetic acid through cholinesterase enzyme reactions. Samples containing the enzymes were incubated with a substrate at 37°C, and test solutions were prepared. The released acids in the test solutions were determined by FIA. Enzyme activity in the samples was subsequently calculated. The relative standard deviation of activity values in human serum were less than 3% (n=5) in all cases. Good correlation was observed for the present and conventional methods in lipase and cholinesterase activity determinations, respectively.
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  • Ho Seob KIM, Dai Woon LEE
    1996 Volume 12 Issue 2 Pages 349-353
    Published: April 10, 1996
    Released: July 04, 2006
    JOURNALS FREE ACCESS
    Quantitative structure-retention relationships (QSRRs) models that predict the reversed-phase liquid chromatographic retention behavior of carboxamides and oxadiazoles are proposed. The intermolecular interaction, isomeric effect and substituent effect were explained by the descriptors determined from calculations with MM+ and AM1 methods. The retention of carboxamides was elucidated by using solvent-accessible surface area and x component of dipole moment. For oxadiazoles, 1-octanol/water partition coefficient (log P) and dipole moment were useful descriptors.
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  • Shu-Gui DAI, Chong-Bong JIA
    1996 Volume 12 Issue 2 Pages 355-361
    Published: April 10, 1996
    Released: July 04, 2006
    JOURNALS FREE ACCESS
    The current advancements of hyphenated techniques, including chromatographic separation with atomic-spectrometric detection and multidimensional chromatography, in environmental analysis are reviewed in this paper.
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  • Shankai ZHAO, Feng ZHONG, Zhihua ZHU
    1996 Volume 12 Issue 2 Pages 363-366
    Published: April 10, 1996
    Released: July 04, 2006
    JOURNALS FREE ACCESS
    The method of matrix-assisted laser desorption/ionization mass spectrometry has been used to solve some bioanalytical problems, which are difficult to analyze by general methods. For the selection of a proper laser wavelength and matrices, seven matrices were used with laser wavelength of 266 and 355nm. The results show that with a wavelength of 355nm better results could be obtained with most of the matrices. The molecular weight of cytochrome c, which was separated by gel electrophoresis and electro-blotted onto nitrocellulose membrane, was determined by matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS). The accuracy was better than 0.1%, which is much higher than that of sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The three components of protein mixture extracted from crude peanut oil was directly determined by MALDI-MS. The result also demonstrated that these proteins are in a free manner. Since these proteins are in a 2S bond, with the traditional method, SDS-PAGE, it is not possible to decide whether the proteins exist in a combination mode or in a free manner. Water-soluble polymers stained with dyes are used in the technique of two-phase aqueous solution, which is used for separating biomaterials. By using MALDI, the number of the dye molecules that react with the polymer molecules can be determined, which is difficult to determine by other methods.
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  • G. Y. JUNG, T. H. KIM, H. B. LIM
    1996 Volume 12 Issue 2 Pages 367-370
    Published: April 10, 1996
    Released: July 04, 2006
    JOURNALS FREE ACCESS
    A UV absorption bipolar capillary electrophoresis system was built on the basis of on-column detection. As an application of capillary electrophoresis, analysis of inorganic anions such as Cl-, SO42- and SO3- is demonstrated. The separation of morpholine (M), N-methylmorpholine (NMM) and N-methylmorpholine-N-oxide (NMMO) using indirect UV absorption technique is discussed as well. Chromate buffer of 10mM was used to provide absorption of the mobile phase additive in indirect detection and precise pH control of the carrier electrolyte. The effect of buffer pH on the separation of M, NMM and NMMO is illustrated.
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  • Suhyeon KIM, Hyun Ju YOO, Jong Hoon HAHN
    1996 Volume 12 Issue 2 Pages 371-375
    Published: April 10, 1996
    Released: July 04, 2006
    JOURNALS FREE ACCESS
    A post-electrophoresis capillary scanning technique has been developed and its feasibility as a high-throughput DNA sequencing method has been demonstrated. In this method, capillary gel electrophoresis separations of DNA sequencing reaction products are spatially and temporally separated with laser-induced fluorescence detection of the products. A 90-cm gel-filled capillary was used to separate a mixture of the fluorescently labeled adenine-terminated DNA fragments of pBluescript SK(-) DNA. The adenine base sequence of the DNA was then determined up to 350 bases with a scan rate of 3.7cm/s, which took 27s for the capillary. We have estimated that the capillary scanner can analyze over 130 capillaries in 1h, which corresponds to a DNA sequencing throughput of about 1 megabase/day.
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