Analytical Sciences
Online ISSN : 1348-2246
Print ISSN : 0910-6340
ISSN-L : 0910-6340
Volume 19 , Issue 5
Showing 1-35 articles out of 35 articles from the selected issue
Rapid Communications
Original Papers
  • Jun ZHONG, Zhimei QI, Han DAI, Chunhai FAN, Genxi LI, Naoki MATSUDA
    Type: Others
    Subject area: Others
    2003 Volume 19 Issue 5 Pages 653-657
    Published: 2003
    Released: December 19, 2003
    JOURNALS FREE ACCESS
    DNA and gold nanoparticles are co-immobilized at a gold electrode through elaborate self-assembly processes. This configuration has proven to be useful as a sensor for phenothiazine drugs, taking advantage of the well-known, relatively large surface area of gold nanoparticles and the strong intercalation between dsDNA and phenothiazine drugs. This modified electrode has demonstrated good sensitivity and stability towards the oxidation of two model phenorthiazine drugs: promethazine and chlorpromazine. A linear dependence between the concentration of phenothiazine drugs and the peak current is observed, with a concentration range of 2.0 × 10-5 - 1.6 × 10-4 M and 1.0 × 10-5 - 1.2 × 10-4 M, and a detection limit of 1.0 × 10-5 M and 7.0 × 10-6 M, for promethazine and chlorpromazine, respectively.
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  • Tadayuki TSUKATANI, Takahiro OBA, Hiroyuki UKEDA, Kiyoshi MATSUMOTO
    Type: scientific monograph
    Subject area: Infomation Science
    2003 Volume 19 Issue 5 Pages 659-664
    Published: 2003
    Released: December 19, 2003
    JOURNALS FREE ACCESS
    A method for the spectrophotometric assay of yeast vitality was developed using 2,3,5,6-tetramethyl-1,4-benzoquinone and tetrazolium salts. The metabolic efficiency of 2,3,5,6-tetramethyl-1,4-benzoquinone by yeast cells was used as an index of yeast vitality. 2,3,5,6-Tetramethyl-1,4-benzoquinone was reduced to 2,3,5,6-tetramethyl-1,4-hydroquinone by yeast cells. Then, the superoxide anion radicals generated from O2 by reduction with 2,3,5,6-tetramethyl-1,4-hydroquinone under alkaline conditions reduced tetrazolium salts to formazan, which exhibited absorbance maxima at 440 nm. A linear relationship between the absorbance and viable cell density was obtained in the range of 1.0 × 105 - 2.0 × 107 cells/ml for a sample solution. During the cultivation of yeast cells, the absorbance showed almost an anti-parallel change with that of glucose in yeast growth and fermentation, suggesting that the absorbance change reflected the vitality of yeast cells.
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  • Saipin THANACHASAI, Shoichiro YOSHIDA, Tadashi WATANABE
    Type: Others
    Subject area: Others
    2003 Volume 19 Issue 5 Pages 665-669
    Published: 2003
    Released: December 19, 2003
    JOURNALS FREE ACCESS
    Hydrogen peroxide sensors where horseradish peroxidase (HRP) is incorporated into pyrrole/3-alkylsulfonate pyrrole copolymer films deposited on an SnO2 electrode (HRP/Py-PS electrode) were investigated with regard to the effects of the fabrication parameters (electropolymerization charge, deposition current density, and electrodeposition solution pH) on the amount of surface-immobilized enzyme and the sensor response. The amount of incorporated enzyme was determined with a method recently developed by ourselves. The results suggest that the amount of entrapped enzyme increases almost linearly with the total charge passed, and strongly depends on the polymer film growth rate and the electropolymerization pH. These findings open up a way to control the amount of enzyme and the resultant response of the biosensor by modifying the preparation conditions.
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  • Sheng-xun SHI, Zhi-guang ZHU, Ran SUO, Chun WANG
    Type: Others
    Subject area: Others
    2003 Volume 19 Issue 5 Pages 671-673
    Published: 2003
    Released: December 19, 2003
    JOURNALS FREE ACCESS
    A method for activating ISE is proposed that can allow determination of the fluoride concentration at ng mL-1 level with good precision and accuracy. Fluoride ISE is activated in 0.5 mol L-1 HClO4 medium and then fluoride is determined in the same medium. The linear range for the determination of fluoride is between 1.00 × 10-2 - 1.00 × 10-7 mol L-1, and the detection limit of the method is 1.0 ng mL-1. The advantage of this method is that it is free from the use of TISAB solution while being, time-saving and labor-saving. A mechanism study of the activation of FISE in HClO4 medium is explained. The method has been used for the determination of trace fluoride in milk and flour with satisfactory results.
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  • Saad S.M. HASSAN, Wagiha H. MAHMOUD, Mohamed A.F. ELMOSALLAMY, Mahra H ...
    Type: scientific monograph
    Subject area: Infomation Science
    2003 Volume 19 Issue 5 Pages 675-679
    Published: 2003
    Released: December 19, 2003
    JOURNALS FREE ACCESS
    Two novel potentiometric membrane sensors responsive to the ibuprofen drug have been developed. These incorporate poly(vinyl chloride) and polyurethane matrix membranes containing 5,10,15,20-tetraphenylporphrinato (TPP) indium (III) ionophore plasticized with dibutylsebacate. The sensors show a near-Nernstian response with anionic slopes of −53 and −55 mV decade-1, over the concentration range of 4.2 × 10-6 - 1.0 × 10-2 and 3.3 × 10-6 - 1.0 × 10-2 M ibuprofen within pH ranges of 4 - 9 and 5 - 9 for PVC and PU matrix membranes, respectively. A sensor based on a polyurethane membrane displays a lower detection limit and a wider linear working range, and a sensor based on a PVC membrane exhibits a better overall selectivity, especially in the presence of lipophilic organic anions. Both sensors are used for the quantification and quality-control assessment of ibuprofen in pharmaceutical preparations. The average recoveries are 99.1±0.3% and 99.3±0.3% for TPP In(III)-PVC and TPP In(III)-PU based membrane sensors, respectively. High selectivities towards ibuprofen in the presence of many anions, drug excipients and diluents are offered by both sensors, which exhibit a non-Hofmeister selectivity pattern.
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  • Qiong HE, Junjie FEI, Shengshui HU
    Type: Others
    Subject area: Others
    2003 Volume 19 Issue 5 Pages 681-686
    Published: 2003
    Released: December 19, 2003
    JOURNALS FREE ACCESS
    Carbon-paste electrodes (CPEs) were studied to elucidate the cathodic stripping voltammetric determination of iodine. At an accumulation potential of 1.0 V (vs. SCE), iodide was preconcentrated on CPEs via an ion-pairing reaction, followed by oxidation to iodine. Then a linear scan voltammogram was recorded after 10 s of quiescent time by a cathodic potential scan from 0.7 V to 0.1 V at a scan rate of 100 mV s-1. A cathodic peak current was obtained at about 0.38 V. Various experiment parameters such as the acidity, chloride concentration, accumulation potential, accumulation time, concentration of cetyltrimethylammonium bromide (CTAB) and scan rate, were optimized to analyze the iodide by employing linear-scan stripping voltammetry. Under the optimal conditions, calibration curves were obtained over a wide concentration range of the iodide ion from 8 × 10-9 mol L-1 to 5 × 10-6 mol L-1 with a detection limit of 2 × 10-9 mol L-1 at an accumulation time of 3 min. The effect of interfering species was evaluated and the procedure was applied to an iodide analysis in table salt, with good results.
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  • Hassan A. ARIDA, Sohair A. EL-REEFY, Abeer M. EL-SAIED
    Type: scientific monograph
    Subject area: Infomation Science
    2003 Volume 19 Issue 5 Pages 687-690
    Published: 2003
    Released: December 19, 2003
    JOURNALS FREE ACCESS
    A new lead(II)-selective electrode has been developed based on bis(acetylacetone)-p-phenylenediamine-lead(II) [LPb(NO3)2]H2O complex ionophore as a sensing material, dioctylphthalate (DOP) as a solvent mediator and PVC as a matrix. This electrode exhibits a linear Nernstian response over the concentration range of 1 × 10-5 - 1 × 10-1 mol l-1 of Pb(II) cation, with a cationic calibration slope of 30.0 ± 0.2 mV/concentration decade and a detection limit of 2 × 10-6 mol l-1 (0.40 ppm). It has a fast response time and can be used for a period of 2 months without any divergence in potentials. The proposed electrode reveals a good selectivity for Pb(II) over a wide variety of other tested cations and could be used in the pH range of 4 - 8. It was successfully used for direct determination of Pb(II) concentration in some samples. The obtained results show a good agreement with those obtained by an atomic absorption spectrometric method. The average recovery obtained is 96.5 ± 0.5% with standard deviation of 1.2% (n = 8).
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  • Jackson S. ALBUQUERQUE, Valdinete L. SILVA, Fernando LIMA, Alberto N. ...
    Type: Others
    Subject area: Others
    2003 Volume 19 Issue 5 Pages 691-694
    Published: 2003
    Released: December 19, 2003
    JOURNALS FREE ACCESS
    This work describes an FIA potentiometric procedure for the quantification of dipyrone in pharmaceutical products. For the detector, a tubular electrode comprising a polymeric membrane containing tetraoctylammonium as an electroactive material (5% w/w), dibutylphtalate as a mediator solvent (65% w/w) and PVC (30% w/w) directly applied above a graphite conductor support was used. This unit was incorporated into a monochannel FI-system with a 0.1 mol/L phosphate buffer solution (pH = 5.2) as the carrier solution. The electrode showed a linear response from 8.0 × 10-4 to 10-1 mol/L dipyrone, a slope of 62.1 ± 0.2 mV/dec in pH 5.2 units, an injection volume of 500 μL and a carrier flow-rate of 6 mL/min. This procedure was applied to the analysis of pharmaceutical formulations (oral and injectable) containing dipyrone; the obtained results gave a relative error of less than 3.9% and coefficients of variation less than 1% and 5%, respectively, for the FIA and classical iodometric methods.
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  • Yukio KANDA, Masafumi TAIRA
    Type: Others
    Subject area: Others
    2003 Volume 19 Issue 5 Pages 695-699
    Published: 2003
    Released: December 19, 2003
    JOURNALS FREE ACCESS
    A flow-injection analysis method for the determination of nitrite and nitrate in natural water samples has been developed that consists of two systems based on their reduction to NO with hydrazine and/or ascorbic acid, followed by chemiluminescence detection. The procedure of sweeping the generated NO into an NOx monitor, by means of a gas-liquid separating coil consisting of microporous polytetrafluoroethylene (PTFE) tubing, offers practical advantages. The adjustment of the carrier gas-flow rates could yield the same calibration graphs for the two measurement systems, and the accumulation sweeping mode provides a higher sensitivity. Chemiluminescence detection allows a wide linear calibration range of 5 × 10-8 to 5 × 10-5 M. The detection limits for nitrate and nitrite, defined as three-times the standard deviation of measurement blanks, are 2 × 10-8 M and 1 × 10-8 M, respectively, and the average precision was 3.2% at ambient natural concentration levels. Recovery tests were between 94% and 106% for a variety of natural water samples. The method is relatively free from interferences from the substances normally found in natural water, and only ferric ion has an effect for the nitrite determination.
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  • Manuel MATEU-SÁNCHEZ, Mercedes MORENO, F.Javier ARREBOLA, Jos&e ...
    Type: Others
    Subject area: Others
    2003 Volume 19 Issue 5 Pages 701-704
    Published: 2003
    Released: December 19, 2003
    JOURNALS FREE ACCESS
    A new analytical method has been validated for determining the insecticide acetamiprid in vegetables using gas chromatography (GC) and different mass spectrometric detection techniques, such as full-scan mass spectrometry (MS), and tandem mass spectrometry (MS/MS). For this purpose, a previous extraction of the vegetable sample was carried out with ethyl acetate. In GC-MS/MS, the lowest detectable concentration was 0.001 mg kg-1, the average recovery rates at various fortification levels (0.015 and 0.030 mg kg-1) ranged between 82.4 and 85.7% and the relative standard deviations were lower than 12.2% in all cases.
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  • M. NOROOZIFAR, M. KHORASANI-MOTLAGH
    Type: scientific monograph
    Subject area: Infomation Science
    2003 Volume 19 Issue 5 Pages 705-708
    Published: 2003
    Released: December 19, 2003
    JOURNALS FREE ACCESS
    A very specific, selective, simple and inexpensive procedure was developed for the speciation of CrVI and CrIII. This method is based on the quantitative extraction of chromate and CrIII (previously oxidized to CrVI) as a tetrabutylammonium-chromate ion-pair in methyl isobutyl ketone (MIBK), and then back extraction and preconcentration with an acidic diphenylcarbazide (DPC) solution. Back extraction was applied to achieve further preconcentration by a final factor of 20. The CrVI-DPC complex was determined in back-extract by a spectrophotometer at 548 nm. Under these extraction conditions, most of the probable concomitant cations and anions remained in the first inorganic phase. The calibration curve was linear up to 0.14 μg L-1 of CrVI with a detection limit of 2.22 ng L-1. The developed procedure was found to be suitable for the determination of the CrVI and CrIII species in various natural water samples with a relative standard deviation of better than 1.6%. The method was successfully applied to the speciation of chromium in spiked natural water samples, and also samples of effluent from a leather treatment plant.
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  • Yi FAN, Yu-Qi FENG, Shi-Lu DA, Ping-Yun FENG
    Type: scientific monograph
    Subject area: Infomation Science
    2003 Volume 19 Issue 5 Pages 709-714
    Published: 2003
    Released: December 19, 2003
    JOURNALS FREE ACCESS
    A β-cyclodextrin bonded silica was synthesized by using a convenient method, and was evaluated as a selective sorbent for the solid-phase extraction of 4-nitrophenol and 2,4-dinitrophenol. When double-distilled water was used as the sample matrix, the sorbent showed a strong capacity to adsorb 4-nitrophenol and 2,4-dinitrophenol; the recoveries were found to be 96% and 99%, respectively, with a 1 L water sample. The selectivity of the sorbent was investigated by using a washing step with methanol. Most of the phenols were washed out with 5 mL of methanol, while 4-nitrophenol and 2,4-dinitrophenol still gave recoveries of 94% and 90%. The solution for efficiently eluting the analytes was optimized and the effect of the inorganic salt on the extraction was examined. In order to investigate the potentiality of the sorbent in dealing with real water samples, water from Donghu lake (Wuhan, China) spiked with nine phenolic compounds at microgram per liter levels were preconcentrated on this cartridge.
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  • Haruyo SANBE, Ken HOSOYA, Jun HAGINAKA
    Type: scientific monograph
    Subject area: Infomation Science
    2003 Volume 19 Issue 5 Pages 715-719
    Published: 2003
    Released: December 19, 2003
    JOURNALS FREE ACCESS
    Uniformly sized molecularly imprinted polymers, which can recognize bisphenol A (BPA), have been prepared by a multi-step swelling and polymerization method using BPA or a structurally related analogue of BPA [p-t-octylphenol (OP) or p-t-butylphenol (BP)] as the template molecule, 4-vinylpyridine as the functional monomer, and ethylene glycol dimethacrylate as the cross-linker. The BP-imprinted polymer showed higher molecular recognition ability for BPA than the OP-imprinted polymer. The BPA- and BP-imprinted polymers were applied for the assay of a trace amount of BPA in river water using column-switching HPLC with fluorescence detection: A BPA-imprinted polymer was used for removal of BPA from the pretreatment eluent as the trap column, and a BP-imprinted polymer was used for selective pretreatment and enrichment of BPA in river water as the pretreatment column. The calibration graph, constructed from peak area data plotted versus BPA concentration, was linear with a correlation coefficient of >0.999 in the concentration ranges of 25 - 1000 ppt. The limit of quantitation was 25 ppt with a 5-ml injection. The column-switching HPLC system was successfully applied for the assay of BPA in river water.
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  • Nobutaka ENDO, Yukari TAKEDA, Mitsuru HIGA, Koji MATSUSAKI
    Type: Others
    Subject area: Others
    2003 Volume 19 Issue 5 Pages 721-725
    Published: 2003
    Released: December 19, 2003
    JOURNALS FREE ACCESS
    A colloidal powder was prepared by fixing polyaniline (PANI, conducting polymer), poly(vinyl alcohol)(PVA, surfactant stabilizer) and a suitable dopant anion to silica-gel powder. This hydrophilic composite colloidal particle incorporates anions with the protonation of PANI in an acidic solution. The anion can be exchanged with other anions when the colloid is immersed in an acidic solution. Thus, the PANI colloid works as an ion exchanger. The ion-exchange properties on the composite colloidal powder were investigated. Anions were successfully and easily exchanged in the order Br- < Cl- < NO3- < ClO4- < SCN-. This ion-exchange selectivity corresponds largely to the ion-exchange equilibrium constants, which are based on a hydrophobic interaction between the anion and colloid. However, this ion-exchange selectivity does not agree simply with the lipophilic order, but is instead explainable by a gap in the effective ion-exchange capacity due to a size effect between the micropore on the colloidal particle formed by the dopant anion in polymerization and anion sizes in the hydrophobic environment.
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  • Yukio HIRATA, Etsuro IMAMURA, Yoshifumi YAZAWA
    Type: Others
    Subject area: Others
    2003 Volume 19 Issue 5 Pages 727-730
    Published: 2003
    Released: December 19, 2003
    JOURNALS FREE ACCESS
    A serially coupled column system for capillary supercritical fluid chromatography was constructed by connecting two capillary columns of different polarities using or without using a coupling restrictor. The influence of the column sequence, the size of the coupling restrictor and the column temperature on the polarity of the system were studied. The system without a coupling restrictor (the directly coupled system) provided an intermediate polarity between two columns, depending on the column geometry, such as the film thickness and column length, although it slightly shifted to that of the first column. In the system with a coupling restrictor, the contribution of the second column to the overall retention increased with its resistance. The use of a coupling restrictor allowed to control the polarity of the coupled system virtually over the whole range between two columns. The temperature was an additional effective parameter for tuning the polarity of the system.
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  • Jiatai WEI, Norio TESHIMA, Shinsuke OHNO, Tadao SAKAI
    Type: scientific monograph
    Subject area: Infomation Science
    2003 Volume 19 Issue 5 Pages 731-735
    Published: 2003
    Released: December 19, 2003
    JOURNALS FREE ACCESS
    A kinetic-catalytic spectrophotometric flow-injection method was developed for the rapid and sensitive determination of trace amounts of copper(II). The method is based on the catalytic effect of copper(II) on the redox reaction of cysteine with iron(III). Iron(II) produced by the catalytic reaction reacts with 2,4,6-tris(2-pyridyl)-1,3,5-triazine (TPTZ) to form the iron(II)-TPTZ complex (λmax = 593 nm). By measuring an absorbance of the complex, one could determine 0.05 - 8 ppb copper(II) with the relative standard deviations (n = 10) of 1.6%, 1.3%, and 0.8% for 0.5 ppb, 1 ppb, and 2 ppb copper(II), respectively. The limit of detection (S/N = 3) was 0.005 ppb. The sample throughput was 30 h-1. The proposed method was successfully applied to the determination of copper in natural water and serum samples.
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  • Salma M.Z. AL-KINDY, Fakhr Eldin O. SULIMAN, Salama B. SALAMA, Mohamed ...
    Type: scientific monograph
    Subject area: Infomation Science
    2003 Volume 19 Issue 5 Pages 737-742
    Published: 2003
    Released: December 19, 2003
    JOURNALS FREE ACCESS
    A simple sequential injection (SI) method is reported for the determination of the non-ionic surfactant polyoxyethylene sorbitan monoleate (Tween-80). The proposed method is based on a fluorescence enhancement of the probe 4′,5′-dibromo-2′,7′-dinitro fluorescein, disodium salt (Eosin B) in the presence of a surfactant. The procedure is optimized using the univariate method of optimization. The optimum operating conditions are as follows: reagent concentration, 40 ppm; pH, 4.5; aspirated volumes of sample and reagent, 120 μL and 100 μL, respectively. With the optimum conditions described, linear calibration curves were obtained from 10 - 200 ppm. The detection limit was 1.7 ppm and the maximum relative standard deviation of the method was 2.7% (n = 5). The fluorescence excitation and emission were fixed at λex = 545 nm and λem = 585 nm. The method was successfully applied to the determination of (TW-80) in natural water samples.
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  • M.Hosein ARBAB-ZAVAR, G.Hosein ROUNAGHI, Mahmoud CHAMSAZ, Mahboube MAS ...
    Type: Others
    Subject area: Others
    2003 Volume 19 Issue 5 Pages 743-746
    Published: 2003
    Released: December 19, 2003
    JOURNALS FREE ACCESS
    A technique for determination of mercury is described; it is based on electrolytic reduction of Hg(II) ion on a graphite cathode, the trapping of mercury vapor and its volatilization into a quartz tube aligned in the optical path of an atomic absorption spectrometer. The electrochemical cell consisted of a graphite cathode and an anode operating with constant direct current for the production of mercury atoms. A pre-activated graphite rod was used as the cathode material. The optimum conditions for electrochemical generation of mercury cold vapor (the electrolysis time and current, the flow rate, the type of electrode and electrolyte) were investigated. The characteristic electrochemical data with chemical cold vapor using NaBH4-acid were compared. The presence of cadmium(II), arsenic(III), antimony(III), selenium(IV), bismuth(III), silver(I), lead(II), lithium(I), sodium(I) and potassium(I) showed interference effects which were eliminated by suitable separation techniques. The calibration curve is linear over the range of 5 - 90 ng ml-1 mercury(II). The detection limit is 2 ng ml-1 of Hg(II) and the RSD is 2.5% (n = 10) for 40 ng ml-1. The accuracy and recovery of the method were investigated by analyzing spiked tap water and river water.
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  • Alaa S. AMIN, Gamal H. RAGAB
    Type: Others
    Subject area: Others
    2003 Volume 19 Issue 5 Pages 747-751
    Published: 2003
    Released: December 19, 2003
    JOURNALS FREE ACCESS
    Four rapid, simple, reproducible and sensitive methods (A-D) for assaying domperidone (I) and metoclopramide (II) in a bulk sample and in dosage forms were investigated. The first and second methods, A and B, are based on the oxidation of I and/or II by Fe3+ in the presence of o-phenanthroline (o-phen) or bipyridyl (bipy). The formation of tris-complex upon reactions with Fe3+-o-phen and/or Fe3+-bipy mixture in an acetate buffer solution of the optimum pH-values was demonstrated. Methods C and D involve the addition of excess Ce4+ and the determination of unreacted oxidant by a decrease of the red color of chromotrope 2R (C2R) at a suitable λmax of 528 nm for method C, or a decrease in the orange pink color of Rhodamine 6G (Rh6G) at a suitable λmax value of 525 nm for method D. A regression analysis of Beer-Lambert plots showed a good correlation in the concentration range of 0.2 - 5.8 μg ml-1. The apparent molar absorptivity, Sandell sensitivity, detection and quantification limits were calculated. For a more accurate analysis, the Ringbom optimum concentration ranges are 0.35 - 5.6 μg ml-1. The developed methods were successfully applied to the determination of domperidone and metoclopramide in bulk and pharmaceutical preparations without any interference from common excipients.
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  • Yu-Zhen CAO, Hong CHEN, Hai-Long WU, Ru-Qin YU
    Type: Others
    Subject area: Others
    2003 Volume 19 Issue 5 Pages 753-756
    Published: 2003
    Released: December 19, 2003
    JOURNALS FREE ACCESS
    A novel algorithm, alternatively minimizing coupled vector (COV) resolution error and PARAFAC error algorithm, is proposed in this paper. This algorithm can overcome the problem of slow convergence and is insensitive to the estimation of component number, such problems are unavoidable while using the traditional parallel factors analysis (PARAFAC) algorithm. In other words, this algorithm is capable of improving the computing speed and providing accurate resolutions provided that the number of factors used in the computation is no less than that of the actual underlying ones. The characteristic performances were demonstrated with a novel fluorescence data array.
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  • Kazuki KAGESHIMA, Takaya TAKEI, Yoshinori SUGITANI
    Type: Others
    Subject area: Others
    2003 Volume 19 Issue 5 Pages 757-759
    Published: 2003
    Released: December 19, 2003
    JOURNALS FREE ACCESS
    High-frequency spectroscopy has been applied to monitoring the stability of oil-in-water emulsions. It was found that stable emulsions showed absorption peaks at around 550 MHz; further, they shifted from lower to higher frequencies with time. The rate of increase of the frequencies was dependent on the amount of emulsifier added. These results show that the stability of emulsions can be monitored by the amount of the frequency shift.
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  • Naokazu YOSHIKAWA, Takeko MATSUMURA-INOUE
    Type: scientific monograph
    Subject area: Infomation Science
    2003 Volume 19 Issue 5 Pages 761-765
    Published: 2003
    Released: December 19, 2003
    JOURNALS FREE ACCESS
    Seven useful mixed-ligand complexes in the form of [Ir(terpy)(L)Cl]2+ were prepared and their spectroscopic and electrochemical properties were investigated. The ligands used were terpy = 2,2′:6′,2″-terpyridine, L = 2,2′-bipyridine, 4,4′-dimethyl-2,2′-bipyridine, 4,4′-diphenyl-2,2′-bipyridine, 1,10-phenanthroline, 5-phenyl-1,10-phenanthroline, 4,7-diphenyl-1,10-phenanthroline, 2,3-bis(2-pyridyl)pyrazine. Synthetic methods were developed by a sequential ligand-replacement which occurred in the reaction vessel using a microwave oven. All complexes showed that LUMOs are based on the π-system contribution of the terpyridine ligand for [Ir(terpy)(bpy)Cl]2+, [Ir(terpy)(dmbpy)Cl]2+, [Ir(terpy)(dpbpy)Cl]2+, [Ir(terpy)(phen)Cl]2+, [Ir(terpy)(dpphen)Cl]2+ and [Ir(terpy)(phphen)Cl]2+. On the other hand, the LUMO in the [Ir(terpy)(bppz)Cl]2+ complex is localized on the π-system of the bppz ligand, whereas the HOMOs in the iridium complexes are localized on the terpyridine ligand. It was found that Ir(terpy)(L)Cl emits in a fluid solution at room temperature. The ancillary ligands, such as terpy and bpy, have been explored to extend the lifetime of the triplet 3(π-π*) excited states of Ir(III) terpyridine complexes. Ir(III) terpyridine units with an electron donor (dmbpy) or electron acceptor substituents (terpy, dpbpy, phphen, dpphen and bppz) are found to decrease the energy of the 3LC states for use as photosensitizer molecular components in supramolecular devices. The spectroscopic and electrochemical details are also reported herein.
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Notes
  • Toshio YAO, Shotaro HANDA
    Type: Others
    Subject area: Others
    2003 Volume 19 Issue 5 Pages 767-770
    Published: 2003
    Released: December 19, 2003
    JOURNALS FREE ACCESS
    Aldehyde biosensors were constructed by cross-linking formaldehyde dehydrogenase (FDH) or aldehyde dehydrogenase (ADH) and bovine serum albumin on the surface of a redox Os-polymer-coated electrode. The prepared aldehyde biosensors responded rapidly (within 30 s) to aldehydes without the addition of a soluble mediator, because the inner redox Os-polymer film effectively mediated the electron transfer from NADH generated enzymatically into the outer enzyme film to a glassy carbon electrode. An FDH/Os-polymer electrode responded linearly over the concentration range of 2 × 10-6 - 5 × 10-4 M for formaldehyde, while an ADH/Os-polymer electrode, though responding similarly to long chain aldehydes, such as propionaldehyde and butylaldehyde, responded linearly over the concentration range of 4 × 10-6 - 2 × 10-4 M for acetaldehyde.
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  • Takashi KATSU, Nozomi OKAKI, Kiyoyuki WATANABE, Kiyoka TAKAISHI, Hiroc ...
    Type: Others
    Subject area: Others
    2003 Volume 19 Issue 5 Pages 771-774
    Published: 2003
    Released: December 19, 2003
    JOURNALS FREE ACCESS
    p-tert-Butylcalix[8]arene-octaacetic acid octaethyl ester and calix[8]arene-octaacetic acid octaethyl ester well recognized 2-phenylethylamine and phenylalanine methyl ester compared with the corresponding calix[6]arene derivatives. Moreover, the calix[8]arene derivatives, especially one having tert-butyl groups, gave better selectivity against biologically active amines having a complicated structure, such as norephedrine. We considered the interaction between calixarenes and organic ammonium ions from the viewpoint of molecular symmetries.
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  • Kiyoharu NAKATANI, Jun YAMASHITA, Tomomi SEKINE, Minoru TORIUMI, Toshi ...
    Type: Others
    Subject area: Others
    2003 Volume 19 Issue 5 Pages 775-777
    Published: 2003
    Released: December 19, 2003
    JOURNALS FREE ACCESS
    The dissociation of t-butyl methacrylate-methacrylic acid copolymers in dimethyl sulfoxide was analyzed by a nonaqueous potentiometric titration technique. The negative logarithm of the dissociation constant of the monomer unit of a methacrylic acid (MAA) monotonously increased with the increasing degree of dissociation corresponding to the titrant/MAA amount ratio, and was highly influenced by the copolymerization ratio. The results are discussed in terms of the suppression of the dissociation of MAA by a neighboring charged methacrylate anion unit.
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  • Kanakapura BASAVAIAH, Hulikal Chandrashekar PRAMEELA
    Type: Others
    Subject area: Others
    2003 Volume 19 Issue 5 Pages 779-784
    Published: 2003
    Released: December 19, 2003
    JOURNALS FREE ACCESS
    One titrimetric and two spectrophotometric procedures have been reported for the determination of albendazole and its tablets. Using titrimetry, the drug was titrated directly with Chloramine-T under acidic conditions using a Methyl Orange indicator. The spectrophotometric procedures involve treating the sample solution with a measured excess of Chloramine-T in an acid medium, followed by an estimation of unreacted Chloramine-T by reacting with a fixed amount of either Methyl Orange or Indigo Carmine dye solution and measuring the absorbance at 510 nm or 610 nm. The stoichiometric ratio, which forms the basis for the calculations in titrimetry as well as the range of the applicability, are reported. The Beer’s law range and sensitivity values for spectrophotometric procedures are included. The methods were applied to the determination of albendazole in tablets with satisfactory results.
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  • Ryoko CHIBA, Ayako OGASAWARA, Teppei KUBO, Hiroyuki YAMAZAKI, Masuo UM ...
    Type: Others
    Subject area: Others
    2003 Volume 19 Issue 5 Pages 785-789
    Published: 2003
    Released: December 19, 2003
    JOURNALS FREE ACCESS
    A column-switching high-performance liquid chromatographic method with fluorescence detection was developed for the simultaneous determination of four benzamide-type anti-psychotic drugs: sulpiride, tiapride, sultopride and metoclopramide in human serum. In this method, a TSKgel Super-ODS column was used as an analytical column, and a TSKgel G 2000SW was prepared as a pretreatment column. Under the optimized analytical conditions, four benzamide-type anti-psychotic drugs were eluted within 18 min. The detection limits (S/N = 3) for sulpiride, tiapride, sultopride and metoclopramide are 1 ng/ml, 4 ng/ml, 2 ng/ml and 0.5 ng/ml, respectively. Finally, the method was applied to the determination of sulpiride in human serum samples obtained after a single oral dose of sulpiride.
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  • Hideo HAYASHI, Takahiro HONDA, Taku IWATA, Tomokazu TANAKA, Masataka H ...
    Type: Others
    Subject area: Others
    2003 Volume 19 Issue 5 Pages 791-793
    Published: 2003
    Released: December 19, 2003
    JOURNALS FREE ACCESS
    Electrothermal vaporization with two filaments was studied for low-pressure helium-ICP-MS. A 10-μl volume of sample was dried and vaporized, and then introduced to the ICP. With this technique, four elements were simultaneously determined with the acceptable precisions (RSD ca. 10%). The detection limit based on 3σ of background signals approached the fractional ppb range. The proposed method was successfully applied to the analysis of the certified reference material for human hair.
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Advancements in Instrumentation
Instrumental Achievements
  • Dinçer ÜLKÜ, F. Betül KAYNAK, Orhan ATAKOL, Meci ...
    Type: scientific monograph
    Subject area: Infomation Science
    2003 Volume 19 Issue 5 Pages 799-800
    Published: 2003
    Released: December 19, 2003
    JOURNALS FREE ACCESS
    The title compound is a double oxygen-bridged dimeric heteronuclear metal complex. The coordination around the Cu atom is distorted square-planar involving two O and two N atoms from the bis(salicylidene)-1,3-propanediamine ligand. The Zn atom in the molecule has a distorted tetrahedral coordination sphere consisting of the two O atoms of the ligand and the two Br atoms. The bridging plane between the metal atoms is not planar.
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  • Manuel SORIANO-GARCÍA, Ezequiel HUIPE-NAVA, Virgilio Mendoza GO ...
    Type: scientific monograph
    Subject area: Infomation Science
    2003 Volume 19 Issue 5 Pages 801-802
    Published: 2003
    Released: December 19, 2003
    JOURNALS FREE ACCESS
    C15H18O5 is orthorhombic, P212121. The unit-cell dimensions at 293 K are a = 6.526(3), b = 10.247(4), c = 21.008(13)Å, V = 1404.8(12)Å3, Dx = 1.316 g/cm3, and Z = 4. The R value is 0.044 for 1288 observed reflections. The A, B and C rings adopt chair, twist, and half-chair conformations. The absolute configuration is inferred from the C6 stereochemistry of (+)-cedrol. The crystal structure is stabilized by an O-H…O hydrogen bond and van der Waals forces.
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  • Maryam RANJBAR, Abolghasem MOGHIMI, Hossein AGHABOZORG
    Type: scientific monograph
    Subject area: Infomation Science
    2003 Volume 19 Issue 5 Pages 803-804
    Published: 2003
    Released: December 19, 2003
    JOURNALS FREE ACCESS
    A polymeric self-assembled complex {[Pb(pydc)(pydc·H2)(H2O)2]2}n is prepared from the complexation of a novel pyridine containing self-assembling system, LH2, [pyda·H2]2+[pydc]2- (pyda = 2,6-pyridindiamine and pydc·H2 = 2,6-pyridinedicarboxilic acid) and lead(II) nitrate in 84% yield. The characterization was performed using X-ray crystallography. The crystal system is triclinic with space group P and two molecules per unit cell. The unit cell dimensions are a = 6.913(2)Å, b = 10.687(4)Å and c = 11.182(4)Å with α = 92.805(6)°, β = 101.821(6)° and γ = 95.688(6)°. The final R value is 0.0373 for 4633 reflections measured. This compound is a nine-coordinate binuclear complex with two metal fragments linked via the central four-membered Pb2O2 ring. The crystal also contains a neutral [pydc·H2] molecule, that form hydrogen and coordination bonds that dominate the crystal packing, by forming layers of molecules.
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  • Takashi YOKOYAMA, Gen MURAKAMI, Haruo AKASHI, Michio ZENKI
    Type: Others
    Subject area: Others
    2003 Volume 19 Issue 5 Pages 805-806
    Published: 2003
    Released: December 19, 2003
    JOURNALS FREE ACCESS
    Crystal structure of zwitterionic trimethylammoniopropane sulfonate (Z1-Methyl) was determined by single-crystal X-ray diffractometry. Z1-Methyl crystallized in the monoclinic system, space group P21, with a = 6.3639(2), b = 10.9237(4), c = 8.1505(4)Å, β = 111.078(2)°, V = 528.69(4)Å3, Z = 2. An inter-molecular ionic association was observed in the crystal. The shortest distance between the methyl protons of the trimethylammonium group and the oxygens of the sulfonate group was 2.51(2)Å.
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  • Ichiro TAKAHASHI, Shigeki KAMIMURA, Minoru HATANAKA, Hidehiko KITAJIMA ...
    Type: scientific monograph
    Subject area: Infomation Science
    2003 Volume 19 Issue 5 Pages 807-808
    Published: 2003
    Released: December 19, 2003
    JOURNALS FREE ACCESS
    In the crystal structure of TBM-trihydrate three waters of crystallization were found to locate dissymmetrically. Thus, one of them forms a chelated ring with the neighboring C=O and N-H of TBM. Two other ones bind each other through hydrogen bonding and two sets of which form a cyclic dimer by hydrogen bonding (namely, water-tetramer). A C=O group binds by hydrogen bonding to each of the tetrameric water. The spatial volume occupied by water-teramer appears to be sufficient for complexation with organic molecules.
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