Analytical Sciences
Online ISSN : 1348-2246
Print ISSN : 0910-6340
ISSN-L : 0910-6340
Volume 19 , Issue 3
Showing 1-30 articles out of 30 articles from the selected issue
Original Papers
  • Toshimasa TOYO’OKA, Tomomi MANTANI, Masaru KATO
    Type: scientific monograph
    Subject area: Infomation Science
    2003 Volume 19 Issue 3 Pages 341-346
    Published: 2003
    Released: July 31, 2003
    JOURNALS FREE ACCESS
    The reversible labeling of tyrosine (Tyr)-containing peptide, which involves detection and recovery, is described in this paper. The phenolic-OH in Tyr structure reacted with 4-fluoro-7-nitro-2,1,3-benzoxadiazole (NBD-F) under a mild condition at room temperature in alkaline medium. The resulting derivative absorbed at around 280 nm and 380 nm. However, the fluorescence was very weak. The NBD moiety in the derivative was efficiently removed by the treatment of N-acetyl-L-cysteine (N-AcCys), and the original peptide before the labeling was completely recovered. The proposed procedure was successfully applied to the reversible labeling of N-terminal amine-blocked peptides, i.e., N-AcTyr-Val-Gly, Z-Glu-Tyr, Z-Phe-Tyr, N-Formyl-Met-Leu-Tyr, and N-AcArg-Pro-Pro-Gly-Phe-Ser-Pro-Tyr-Arg. Although the proposed method could not recover the N-terminal amine-free peptides without blocking, the selective detection and the recovery of Tyr-containing peptide fragments were possible by the combination with enzyme digestion. The reversible labeling of Tyr-containing peptide was demonstrated with [Tyr8]-bradykinin as a model for high-molecular-mass peptides and proteins. The peptide fragments containing NBD-O-Tyr moiety, obtained after the digestion, were easily discriminated from various peptides with the monitoring of UV and FL, because the target peptide did not fluoresce, but absorbed at both 280 nm and 380 nm. The peptide fragment containing Tyr was finally recovered from the de-labeling reaction with N-AcCys. The proposed method hence provides a novel technique for the reversible labeling of Tyr-containing peptides, which will enable the selective detection and the recovery of the original peptide.
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  • Zheng-Hua SONG, Shuang HOU
    Type: scientific monograph
    Subject area: Infomation Science
    2003 Volume 19 Issue 3 Pages 347-352
    Published: 2003
    Released: July 31, 2003
    JOURNALS FREE ACCESS
    A novel analytical procedure based on chemiluminescence (CL) detection was described for the determination of lysozyme at ng ml-1 level by using controlled-reagent-release technology in a flow injection system. The analytical reagents involved in the CL reaction, including luminol and periodate, were both immobilized on the anion-exchange resins in the flow injection system. Through water injection, luminol and periodate were eluted from the anion-exchange column to generate the chemiluminescence, which was inhibited in the presence of lysozyme. By measuring the decrease of CL intensity, one could analyze the lysozyme quantitatively. The decrement of CL emission was linear over the logarithm of lysozyme concentration in the range of 30 - 1000 ng ml-1. A typical analytical procedure, including sampling and washing, could be performed in 0.5 min at a flow rate of 2.0 ml min-1, giving a throughput of 120 h-1, with a relative standard deviation of less than 3.0%. The proposed method was applied successfully to the determination of lysozyme in human tear and saliva samples, and the recovery was from 92.0% to 105.7%.
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  • Mohammad Reza GANJALI, Azadeh DAFTARI, Majid FAAL-RASTEGAR, Abolghasem ...
    Type: scientific monograph
    Subject area: Infomation Science
    2003 Volume 19 Issue 3 Pages 353-356
    Published: 2003
    Released: July 31, 2003
    JOURNALS FREE ACCESS
    A novel poly(vinyl chloride) (PVC) membrane electrode based on naphto-9-crown-3 was prepared and tested for the selective detection of beryllium ions. A suitable lipophilicity of the carrier and appropriate coordination ability were found to be essential for designing an electrode with good response characteristics. A PVC membrane with 9% naphtho-9-crown-3 carrier, 58% o-NPOE plasticizer, 3% tetraphenylborate anionic excluder and 30% poly(vinyl chloride) satisfied these requirements. The proposed sensor displayed a linear response to beryllium over a wide concentration range of 1.0 × 10-1-8.0 × 10-6 M with a Nernstian slope of 29.5 mV per decade. The electrode showed very short response time (<15 s) and could be used in the pH range 3.5 - 9.0. The selectivity coefficient for alkali, alkaline earth, transition and heavy metal ions was smaller than 4.0 × 10-4. The sensor was successfully used as an indicator electrode in the potentiometric titration of Be2+ with EDTA. The proposed Be(II) sensor was also used for the determination of Be2+ ions in binary mixtures.
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  • Won-Sik HAN, Su-Jung YOO, Sung-Hoon KIM, Tae-Kee HONG, Koo-Chun CHUNG
    Type: scientific monograph
    Subject area: Infomation Science
    2003 Volume 19 Issue 3 Pages 357-360
    Published: 2003
    Released: July 31, 2003
    JOURNALS FREE ACCESS
    We compared the slopes of the EMF responses and the response range of a solid contact electrode based on a tribenzylamine ionophore with those based on a tris(2-phenylethyl)amine ionophore and a tris(3-phenylpropyl)amine ionophore. Their slopes of the EMF responses showed, respectively, 57.7, 58.1, 59.0 mV pH-1 (at 20±0.2°C). Also, the linear pH response dynamic ranges were 2.74 - 10.63 for tribenzylamine-based SCEs, pH 4.47 - 12.59 for tris(2-phenylethyl)amine, and pH 4.60 - 13.24 for tris(3-phenylpropyl)amine. When the slopes of the EMF responses and the response range were considered, as the length of the replaced alkyl chain increased between the nitrogen atom and the phenyl group in the ionophore, though the dynamic range and the slopes of the EMF responses of these electrodes did not show any particularly different results, their response ranges moved toward the alkali range (shifted to pH 14). When it was directly applied to cow’s milk (in pH range of 6.0 - 8.5), we could obtain the same satisfying results. This electrode continuously contacted a Tris 7.50 buffered solution as well as cow’s milk for one month without any loss of performance. Also, especially, these electrodes showed very good results, such as stabilization of the base potential as well as the best reproducibility and response time (<10 s).
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  • Wagiha H. MAHMOUD
    Type: scientific monograph
    Subject area: Infomation Science
    2003 Volume 19 Issue 3 Pages 361-365
    Published: 2003
    Released: July 31, 2003
    JOURNALS FREE ACCESS
    Poly(vinyl chloride) membrane sensors for Ca(II) ions were constructed based on bilirubin (1,3,6,7-tetramethyl-4,5-dicarboxyethy-2,8-divinyl-[b-13]-dihydrobilenone) as a neutral carrier in the presence of various plasticizers (o-nitrophenyloctyl ether, dioctyl phethalate and dibutyl sebacate), which were used as solvent mediators to incorporate the carrier into the membranes. The role of plasticizers as a medium of complexation was demonstrated. The influences of an anionic excluder, the pH and foreign ions were investigated. The selectivity coefficients were measured by a separate solution method. Among the plasticizers used, o-nitrophenyloctyl ether gave the best selectivity in the presence of large concentrations of alkali and alkaline earth’s metal ions. Using sensor number I, a linear calibration graph with a good Nernstian slope of 29.5±0.8 mV was obtained for Ca(II) concentrations of 5×10-7-10-2 mol l-1 with a detection limit of 3×10-7 mol l-1 (12 ppb). The sensor can be used for more than 3 months with good reproducibility and a fast response time of 10 s. The developed sensor has been successfully applied to the analysis of some pharmaceutical formulations, baby-food products and human plasma. Moreover, it can be used as an indicator sensor in the potentiometric titration of Ca(II) with EDTA.
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  • Eduardo BOLEA, Francisco LABORDA, Juan R. CASTILLO
    Type: scientific monograph
    Subject area: Infomation Science
    2003 Volume 19 Issue 3 Pages 367-372
    Published: 2003
    Released: July 31, 2003
    JOURNALS FREE ACCESS
    A flow injection system for the determination of selenium by electrochemical hydride generation and quartz tube atomic absorption spectrometry is described. The generator consists of an electrolytic flow-through cell with a concentric arrangement and a packed cathode made of particulated lead. The influences of sample flow rate, carrier gas flow rate and electrolysis current on the hydrogen selenide generation have been critically studied. Both sample flow rate and electrolysis current play important roles in the efficiency of the hydride generation process. A characteristic mass of 2.4 ng and a concentration detection limit of 17 μg l -1 were obtained for a sample volume of 420 μl.
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  • Susumu KAWAKUBO, Yuka OKAZAKI, Masaaki IWATSUKI
    Type: scientific monograph
    Subject area: Infomation Science
    2003 Volume 19 Issue 3 Pages 373-378
    Published: 2003
    Released: July 31, 2003
    JOURNALS FREE ACCESS
    A flow-injection determination method was proposed for the speciation of reactive species of iron in non-acidified water samples. Iron was determined by the spectrophotometric monitoring of the iron-catalyzed oxidation of o-phenylenediamine with hydrogen peroxide. The reactive iron was characterized as Fe3+ and FeIIILi3-in, where i = 1 or 2 for a unidentate ligand and i = 1 for a bidentate ligand (Ln-) from the chemical equilibria of hydroxo, oxalato and fluoro Fe(III) complexes. A useful parameter was also proposed to check the reliability of the determination when suffering the adsorption of iron on the inner wall of a PTFE tube of a flow-injection system. Under the optimized FIA condition and by measuring the peak height, a linear calibration curve of iron was obtained up to 0.1 mg L-1 with a detection limit of 0.1 μg L-1. The proposed method was successfully applied to the speciation of reactive and unreactive iron in tap- and river-water samples.
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  • Junichi MATSUMOTO, Bunji NAKANO, Totaro IMASAKA
    Type: scientific monograph
    Subject area: Infomation Science
    2003 Volume 19 Issue 3 Pages 379-382
    Published: 2003
    Released: July 31, 2003
    JOURNALS FREE ACCESS
    A new type of compact supersonic jet/resonance-enhanced multiphoton ionization/time-of-flight mass spectrometer is described. The analytical instrucment, consisting of a single turbo molecular pump equipped with a rotary pump, was maintained at <2×10-3 Pa when a 0.3-atm sample was injected into a vacuum at 10-Hz using a 200-μs pulse valve. The diameters of the extraction and ground skimmer electrodes were expanded to 30 mm in order to avoid strong focusing and defocusing of the ion, and the optimum conditions for the system were investigated. The mass spectrometer functioned as expected: (1) no defocusing of the ion beam was observed even when the potential of the einzel lens was adjusted to zero; (2) the direction of the ion beam to an assembly of microchannel plates deviated in the expected manner when the potential of the defection electrode was changed from 0 to 30 V.
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  • Junichi MATSUMOTO, Bunji NAKANO, Totaro IMASAKA
    Type: scientific monograph
    Subject area: Infomation Science
    2003 Volume 19 Issue 3 Pages 383-386
    Published: 2003
    Released: July 31, 2003
    JOURNALS FREE ACCESS
    A compact supersonic jet/multiphoton ionization/mass spectrometer (SSJ/MPI/MS) equipped with a single pump system was developed for use in the analysis of dioxin. A mass spectrum and multiphoton ionization spectrum were obtained for chlorobenzene and dibenzofuran using an optical parametric oscillator (OPO) for excitation and subsequent ionization. The detection limit for chlorobenzene (S/N = 3) was 0.3 ppb, which corresponds to an absolute amount of 0.1 pg. The rotational temperature was 35 K. This slightly high temperature can be attributed to the long nozzle throat used in the instrument.
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  • Tomohiro UCHIMURA, Hirokazu KANDA, Totaro IMASAKA
    Type: scientific monograph
    Subject area: Infomation Science
    2003 Volume 19 Issue 3 Pages 387-389
    Published: 2003
    Released: July 31, 2003
    JOURNALS FREE ACCESS
    Two-color (1+1′) resonance-enhanced multiphoton ionization/time-of-flight mass spectrometry (REMPI/TOF-MS) combined with supersonic jet (SSJ) spectrometry has been demonstrated. The methodology uses a two-color laser beam consisting of a Stokes beam generated by stimulated Raman scattering (SRS) and a fundamental beam for the excitation and subsequent ionization of p-dichlorobenzene. The MPI signal was found to be substantially increased when a two-color laser beam was employed. This approach greatly simplifies the analytical system and reduces the cost of the instrumentation required for two-color ionization. The potential advantage of applying this method for the analysis of polychlorinated dibenzo-p-dioxin (PCDD) and polychlorinated dibenzofuran (PCDF) emitted from an incinerator is discussed.
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  • Kosei UENO, Haeng-Boo KIM, Noboru KITAMURA
    Type: scientific monograph
    Subject area: Infomation Science
    2003 Volume 19 Issue 3 Pages 391-394
    Published: 2003
    Released: July 31, 2003
    JOURNALS FREE ACCESS
    A polymer microchannel chip with a symmetrical or unsymmetrical zigzag-side-walled structure was fabricated by an imprinting method, and applied to study shape effects on solution flow characteristics as well as on the liquid/liquid extraction efficiency of an aluminium(III) chelate complex (Al-DHAB: DHAB = o,o′-dihydroxyazobenzene) in a microchannel chip. In an unsymmetrical zigzag-side-walled channel chip (us-channel), an oil/water interface was sinusoidal, while that in a symmetrical zigzag-side-walled channel chip (s-channel) was flat as long as the observation was made under an optical microscope. It was demonstrated that the efficiency of the water-to-oil (1-butanol) extraction of Al-DHAB in the microchannel was governed by the contact time between the two phases. As the most important results, furthermore, the extraction efficiency was higher in the us-channel, as compared with that in the s-channel, owing to the sinusoidal liquid/liquid interfacial structure and, therefore, to the high interfacial area between the two phases.
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  • Akihiro MATSUMOTO, Taketoshi NAKAHARA
    Type: scientific monograph
    Subject area: Infomation Science
    2003 Volume 19 Issue 3 Pages 395-400
    Published: 2003
    Released: July 31, 2003
    JOURNALS FREE ACCESS
    A trace amount of carbon was determined by atmospheric-pressure helium microwave induced plasma atomic emission spectrometry (He-MIP-AES) with gas-phase sample introduction technique. This method was applied for the generation of a continuous flow of carbon dioxide by the acidification of carbonate ion and hydrogen carbonate ion for the determination of carbon. The generated carbon dioxide was separated from the solution by a simple gas-liquid separator, dried with a desiccant and swept into the MIP with helium carrier gas for analysis. Of the acids and drying agents investigated, hydrochloric acid for acidification and anhydrous calcium chloride as a desiccant were found to be the most appropriate for the generation of carbon dioxide. Under the optimized experimental conditions, the best attainable detection limits at C (I) 193.09 and C (I) 247.86 nm lines were 7.89 and 8.10 μg/l with linear dynamic ranges of 100 to 10000 and 100 to 20000 μg/l for carbon, respectively. The presence of many diverse elements and ions was found to cause a more or less depressing interference by the proposed technique. However, no interference was observed from the following elements and ions: Ca, K, Rb, Br-, Cl-, F- and I-. Finally, the present method has been applied to the determination of carbon in several water samples.
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  • Hiroaki MINAMISAWA, Kenji MURASHIMA, Mayumi MINAMISAWA, Nobumasa ARAI, ...
    Type: scientific monograph
    Subject area: Infomation Science
    2003 Volume 19 Issue 3 Pages 401-404
    Published: 2003
    Released: July 31, 2003
    JOURNALS FREE ACCESS
    A sensitive and simple method for the determination of trace amounts of indium in water samples by graphite furnace atomic absorption spectrometry (GFAAS) after coprecipitation with chitosan was investigated. Indium was quantitatively preconcentrated from water samples by coprecipitation with chitosan at pH 7.0-9.0. The coprecipitant was easily dissolved with acetic acid, and indium in the resulting solution was determined by GFAAS. The addition of lanthanum as a chemical modifier was more effective for the atomic absorbance of indium. The detection limit (S/N ≥ 3) for indium was 0.04 μg dm-3, and the relative standard deviations (n = 5) were 3.5-4.5% at 1.0 μg/100 cm3. The results obtained in this study indicate that the proposed method can be successfully applied to the determination of trace indium in water samples.
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  • Mohammad Ali TAHER, Mahboobeh SHAMSI
    Type: scientific monograph
    Subject area: Infomation Science
    2003 Volume 19 Issue 3 Pages 405-408
    Published: 2003
    Released: July 31, 2003
    JOURNALS FREE ACCESS
    Nickel was quantitatively retained by 2-nitroso-1-naphthol-4-sulfonic acid (Nitroso-S) and tetradecyldimethylbenzylammonium chloride (TDBA Cl) onto benzophenone in the pH range 5.0 - 6.0 from large volumes of aqueous solutions of various samples. After filtration, each solid mass consisting of a nickel complex and benzophenone was dissolved with 5 ml of dimethylformamide (DMF) and the metal was determined by atomic absorption spectrometry (AAS). About 0.6μg of nickel could be concentrated from 200 ml of an aqueous sample, where its concentration was as low as 3.0 ng/ml. Eight replicate determinations of 2.5 μg/ml of nickel in the final DMF solution gave a mean absorbance of 0.112 with a relative standard deviation of 1.9%. The sensitivity for 1% absorption was 98 ng/ml. The interference of a number of anions and cations was studied and the developed optimized conditions were utilized for the trace determination of nickel in various alloys and biological samples.
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  • Peng LIU, Qiaosheng PU, Qiaoyu SUN, Zhixing SU
    Type: scientific monograph
    Subject area: Infomation Science
    2003 Volume 19 Issue 3 Pages 409-414
    Published: 2003
    Released: July 31, 2003
    JOURNALS FREE ACCESS
    Amidino-thiourea immobilized glass beads (AGB I) were prepared and used as the microcolumn packing for the flow injection (FI) on-line separation and preconcentration of Ag(I) coupled with atomic absorption spectrometry (AAS) determination. Base metal ions and anions with a concentration of 2.0 mg mL-1 had no interference with the determination of Ag(I). The limit of detection (LOD) of Ag(I) for a preconcentration time of 60 s with a sampling flow rate of 5.0 mL min-1 for 40.0 ng mL-1 of Ag(I) were 0.50 ng mL-1 with the peak-height absorbance mode and 1.26 ng mL-1 with the peak-area absorbance mode, respectively. The relative standard deviations (RSD) of 7 replicate determinations were 0.9% and 0.7% for the peak-height absorbance (H) and the peak-area absorbance (A), respectively. The method was successfully applied to the determination of Ag(I) in ore samples.
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  • Yasuhiro SUZUKI, Masaaki KASAMATSU, Shinichi SUZUKI, Yoshiteru MARUMO
    Type: scientific monograph
    Subject area: Infomation Science
    2003 Volume 19 Issue 3 Pages 415-418
    Published: 2003
    Released: July 31, 2003
    JOURNALS FREE ACCESS
    Trace impurities in lead-tin solders were determined using inductively coupled plasma atomic emission spectrometry (ICP-AES) for the forensic discrimination of solder samples from different origins by a comparison of the concentration for each element. After about 10 mg of sample was accurately measured and taken into a glass tube, 1 ml of HNO3 was added. The tube was capped and heated at 80°C for 10 min. After cooling to the room temperature, 1 ml of HCl and 2 ml of purified water were added. It was then agitated until the sample was completely dissolved, followed by dilution to 10 ml. Five elements (Sb, Bi, Cu, As and Ag) in this solution were determined by ICP-AES. The observed values for these elements in the NIST Standard Reference Material 1131 showed good agreement with the certified ones. Eighteen kinds of solder samples could be distinguished from each other, since all of the pairs among these samples provided remarkable difference in the concentration of the trace elements. The copper concentration should have been excluded from the comparison when it increased after melting by a soldering iron made of copper.
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  • Jing FAN, Yahong CHEN, Suling FENG, Cunling YE, Jianji WANG
    Type: scientific monograph
    Subject area: Infomation Science
    2003 Volume 19 Issue 3 Pages 419-422
    Published: 2003
    Released: July 31, 2003
    JOURNALS FREE ACCESS
    A rapid and sensitive flow-injection spectrophotometric method is proposed for the determination of sulfadiazine and sulfamethoxazole. This method is based on the diazotization of sulfonamide with sodium nitrite, and a coupling reaction of the diazo-compound with α-naphthylamine. The optimum experimental conditions are obtained by using the controlled and weighted centroid simplex method. The linear ranges for the determination of sulfadiazine and sulfamethoxazole are 0.2 - 20 μg ml-1 and 0.1 - 20 μg ml-1 and their detection limits are 0.06 μg ml-1 and 0.05 μg ml-1, respectively, and the sampling frequency is 130 samples per hour. The method has been used to determine sulfadiazine and sulfamethoxazole in pharmaceuticals and urine without separation. The results are in agreement with those obtained by a high-performance liquid chromatograph technique at the 95% confidence level.
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  • B.K. REDDY, J.R. KUMAR, K.J. REDDY, L.S. SARMA, A.V. REDDY
    Type: scientific monograph
    Subject area: Infomation Science
    2003 Volume 19 Issue 3 Pages 423-428
    Published: 2003
    Released: July 31, 2003
    JOURNALS FREE ACCESS
    Benzildithiosemicarbazone (BDTSC) is proposed as a sensitive and selective analytical reagent for the extractive spectrophotometric determination of copper(II). BDTSC reacts with copper(II) the pH range 1.0 - 7.0 to form a yellowish complex. Beer’s law is obeyed in the concentration range 0.5 - 0.4 μg cm-3. The yellowish Cu(II)-BDTSC complex in chloroform shows a maximum absorbance at 380 nm, with molar absorptivity and Sandell’s sensitivity values of 1.63×104 dm3 mol-1 cm-1 and 0.00389 μg cm-2, respectively. A repetition of the method is checked by finding the relative standard deviation (RSD)(n = 10), which is 0.6%. The composition of the Cu(II)-BDTSC complex is established as 1:1 by slope analysis, molar ratio and Asmus’ methods. An excellent linearity with a correlation coefficient value of 0.98 is obtained for the Cu(II)-BDTSC complex. The instability constant of the complex calculated from Edmond and Birnbaum’s method is 7.70×10-4 and that of Asmus’ method is 7.66×10-4, at room temperature. The method is successfully employed for the determination copper(II) in pharmaceutical and environmental samples. The reliability of the method is assured by analyzing the standard alloys (BCS 5g, 10g, 19e, 78, 32a, 207 and 179) and by inter-comparison of experimental values, using an atomic absorption spectrometer.
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  • Toshifumi YOSHIDOME, Zhongyuan DANG, Barry A. MORROW
    Type: scientific monograph
    Subject area: Infomation Science
    2003 Volume 19 Issue 3 Pages 429-435
    Published: 2003
    Released: July 31, 2003
    JOURNALS FREE ACCESS
    Transformations of chemical species formed by the reaction of gaseous BF3 with high pressure and silica preheated at 473 and 1093 K were studied with the use of infrared absorption spectrometry. The species containing -BF2 and the species containing>BF were transformed to each other on the highly-reacted silica depending on the pressure of BF3 in cell, and some of the species containing -BF2 were also desorbed without their transformations to the species containing>BF. H2O played important roles in these transformations.
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Notes
  • Zhao-Yang WU, Guo-Li SHEN, Shi-Ping WANG, Ru-Qin YU
    Type: scientific monograph
    Subject area: Infomation Science
    2003 Volume 19 Issue 3 Pages 437-440
    Published: 2003
    Released: July 31, 2003
    JOURNALS FREE ACCESS
    A quartz-crystal microbalance immunosensor (QCM) has been developed for the direct determination of Schistosoma-japonicum-infected rabbit serum. A self-assembled monolayer with carboxyl groups was first coated on a gold electrode of a quartz-crystal resonator by the spontaneous adsorption of 3-mercaptopropionic acid. Schistosoma-japonicum molecular antigen of 32 kD molecular weight was then covalently attached to the crystal surface. The QCM immunosensor was used to detect infected rabbit serum (IRS49-2000); a maximum titer of 1:800 was achieved.
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  • Kengo IGARASHI, Tasuku AKAGI, Feng-Fu FU, Sadayo YABUKI
    Type: scientific monograph
    Subject area: Infomation Science
    2003 Volume 19 Issue 3 Pages 441-445
    Published: 2003
    Released: July 31, 2003
    JOURNALS FREE ACCESS
    Rare-earth elements in a limestone geological standard (JLs-1) were determined by inductively coupled plasma mass spectroscopy (ICP-MS) using phosphoric acid 2-ethylhexyl ester solvent extraction, which had been established for seawater analysis. First, the limestone sample was divided into two fractions: acetic acid soluble (carbonate fraction) and insoluble (residue). A modification of the method was undertaken to achieve quantitative recovery. With this method most of the REEs in the carbonate fraction were quantitatively recovered, except for the heaviest three REEs (Tm, Tb and Lu). The reason for the poor recoveries of the three elements was investigated, but still remained unclear. The mass-spectroscopic interference of BaO with Eu made an accurate determination of both lighter REEs and Eu at the same time impossible. The precision of this method was better than 20%. The data adopted after analytical consideration were consistent with those previously reported.
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  • Lee Wah LIM, Ji-Ye JIN, Toyohide TAKEUCHI
    Type: scientific monograph
    Subject area: Infomation Science
    2003 Volume 19 Issue 3 Pages 447-449
    Published: 2003
    Released: July 31, 2003
    JOURNALS FREE ACCESS
    An on-column enrichment method was developed for the rapid determination of inorganic anions in natural water. The system was assembled from a syringe pump, a six-port switching valve with a sample-enrichment loop, a separation column and a UV detector. The enrichment efficiency of the system was tested by using inorganic anions as samples. The limits of detection were between 0.6 and 7.7 μg/L. The system was applied to the determination of anions in river and pond-water samples.
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  • Shoji KURATA, Masatoshi NAGAI
    Type: scientific monograph
    Subject area: Infomation Science
    2003 Volume 19 Issue 3 Pages 451-454
    Published: 2003
    Released: July 31, 2003
    JOURNALS FREE ACCESS
    The emission spectra of luminescent trivalent europium (Eu3+) and terbium (Tb3+) complexes were measured using a microscope laser Raman spectrometer with a doubled Nd:YAG laser (532 nm) and an Ar laser (488 nm). Excitation at 532 and 488 nm corresponded to wavelengths of the 7F15D1 band of Eu3+ and the 7F65D4 band of Tb3+, respectively. The Eu3+ and Tb3+ complexes were discriminated by high-resolution emission spectra more distinctly and sensitively than by fluorescence spectrometry, the usual analytical method.
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  • T.M. Bulbul ISLAM, Kazuo YOSHINO, Akinobu SASANE
    Type: scientific monograph
    Subject area: Infomation Science
    2003 Volume 19 Issue 3 Pages 455-460
    Published: 2003
    Released: July 31, 2003
    JOURNALS FREE ACCESS
    The 11B NMR spectra of p-carboxybenzeneboronic acid (PCBA) ions demonstrated that their chemical shifts depend on the pH. At a lower pH, PCBA exists as a mixture of neutral PCBA and the monoanion with a trigonal structure, and at higher pH as the dianion with a tetrahedral structure. In the intermediate pH region, both the mono- and dianion coexist. The pKa of the monoanion of PCBA has been estimated to be 8.53. The complex formation constants of PCBA with several monosaccharides suggest that PCBA-fructose complex is most predominant.
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  • Babu G. GOWDA, Jaldappa SEETHARAMAPPA
    Type: scientific monograph
    Subject area: Infomation Science
    2003 Volume 19 Issue 3 Pages 461-464
    Published: 2003
    Released: July 31, 2003
    JOURNALS FREE ACCESS
    A simple, rapid and sensitive spectrophotometric procedure has been proposed for the assay of fluoroquinolones viz., ciprofloxacin (CPF) and norfloxacin (NRF), and antiallergic drugs viz., methdilazine hydrochloride (MDH) and isothipendyl hydrochloride (IPH) in bulk and pharmaceutical formulations. The method is based on the reaction of selected drugs with Brilliant Blue G (BBG) in NaOAc-AcOH buffer of pH 4.0 for CPF and NRF or in neutral medium for MDH and IPH to give chloroform soluble ion-association complexes. The effects of various parameters have been studied. The ion-association complexes exhibited absorption maxima at 610 nm for CPF, at 614 nm for NRF and MDH, and at 612 nm for IPH. Beer’s law plots were obeyed in the concentration ranges of 0.5 - 6.0, 0.4 - 8.0, 0.1 - 6.0 and 0.2 - 6.1 (mg ml-1 for CPF, NRF, MDH and IPH, respectively, with correlation coefficients not less than 0.9969. Molar absorptivity values as calculated from the Beer’s law data were found to be 2.86×104, 2.64×104, 3.13×104 and 5.51×104 l mol-1 cm-1 for CPF, NRF, MDH and IPH, respectively. The influence of commonly employed excipients in the determination of the studied drugs has been studied. The results obtained by the proposed method were statistically validated.
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