Analytical Sciences
Online ISSN : 1348-2246
Print ISSN : 0910-6340
ISSN-L : 0910-6340
Volume 21 , Issue 3
Showing 1-31 articles out of 31 articles from the selected issue
Call for Papers
Rapid Communications
  • Jun LIU, Xuan-Ming LIU, Su-Yao XIAO, Chuen-Yi TONG, Dong-Ying TANG, Li ...
    2005 Volume 21 Issue 3 Pages 193-195
    Published: 2005
    Released: June 14, 2005
    JOURNALS FREE ACCESS
    To research whether poly-L-lysine-starch nanoparticle (PLL-StNP) could protect DNA from ultrasound damage or not, a series experiments were carried out: plasmid DNA-PLL-StNP complexes were treated with ultrasound for diverse times; the electrophoresis result proved that DNA bound to the complexes all the same. To investigate whether the conjugated DNA was completely protected or not, cDNA fragments bound to PLL-StNP were treated with ultrasound, and matched molecular beacons (MBs) were added. The cDNA-MB-PLL-StNP complexes exhibited dramatically increasing fluorescence, and had the same intensity as that of those MBs that were hybridized with free cDNA fragments. After being treated by ultrasound, the pIRGFP plasmid DNA-PLL-StNP complexes were transferred into COS-7 cells mediated by ultrasound. Green fluorescence protein expressed in most of the cells. Those results indicated that PLL-StNP could completely protect DNA from ultrasound damage. Furthermore, the DNA kept the same function as untreated one.
    Download PDF (197K)
  • Sonoko KIKUCHI, Kazuteru KAWAUCHI, Masaru KUROSAWA, Hisashi HONJHO, Te ...
    2005 Volume 21 Issue 3 Pages 197-198
    Published: 2005
    Released: June 14, 2005
    JOURNALS FREE ACCESS
    The European Union has banned chromium(VI) compounds in electrical and electronic equipment (EEE), such as chromate conversion coating films. Chromium(III) compounds are not banned. Using Raman spectroscopy without any preparation, we distinguished chromium(VI) oxide from chromium(III) oxide and chromium(III) hydroxide in chromate conversion coating films. Raman bands of chromium(VI) oxide were detected in films at around 1000 and 500 cm-1, while chromium(III) compounds generated no bands in the region between 2000 and 200 cm-1. The analysis took about 1 min, whereas the usual diphenylcarbazide-colorimetric method for analyzing chromium(VI) compounds takes about 10 h.
    Download PDF (68K)
Original Papers
  • Yanbei ZHU, Ryota HATTORI, Eiji FUJIMORI, Tomonari UMEMURA, Hiroki HAR ...
    2005 Volume 21 Issue 3 Pages 199-203
    Published: 2005
    Released: June 14, 2005
    JOURNALS FREE ACCESS
    The determination of 34 trace metals in a river water certified reference material (CRM), i.e. JSAC 0301-1, which was issued by the Japan Society for Analytical Chemistry in January 2004, was performed by ICP-MS with a high efficiency nebulizer after preconcentration with a laboratory-made chelating resin-packed minicolumn, with which trace metals were concentrated 100-fold from 50 mL of a river water sample to 0.5 mL of the final analysis solution. Trace metals in JSAC 0301-1 were observed in the concentration range from 19 µg L-1 of Al to 0.000053 µg L-1 of Bi. It was found that most of the concentrations of trace metals, including rare earth elements (REEs), in JSAC 0301-1 were lower than those in JAC 0031, which was also a previously issued CRM prepared with water from the same river as that of JSAC 0301-1. The low concentrations of trace metals in JSAC 0301-1 might be attributed to the fact that there was a heavy rain before collecting the original water sample to prepare the present CRM. Furthermore, the REE distribution patterns of JSAC 0301-1, JAC 0031 and the average values of river water samples in Japan were parallel to each other. These results indicate that the distributions of REEs in JSAC 0301-1 and JAC 0031 were the typical ones of river water samples in Japan.
    Download PDF (69K)
  • Yoshihito OHTSUKA, Yuichi TAKAKU, Jyoji KIMURA, Shun’ichi HISAMA ...
    2005 Volume 21 Issue 3 Pages 205-208
    Published: 2005
    Released: June 14, 2005
    JOURNALS FREE ACCESS
    This paper describes our development of a rapid on-line column/ID-ICP-MS technique for the analysis of plutonium (Pu) in environmental samples using an UTEVA® extraction chromatograph resin (UTEVA resin) column. It took only 40 min to separate and measure Pu in the sample solution, including the time for conditioning the resin column for the next analysis. In our method, Pu in a 3 M nitric acid solution was fed to the UTEVA resin, and then eluted from the resin by reducing Pu to Pu(III) with 3 M nitric acid mixed with 0.01 M ascorbic acid after washing the resin. The outflow from the resin column was directly introduced to an ICP-MS system. The low concentration of ascorbic acid and the small volume of the eluting solution (0.6 mL) made successive stable analysis possible without any skimmer cone clogging. The chemical recovery of Pu during column operation was 70%, and typical lower detection limits for 239Pu, 240Pu and 242Pu were 9.2, 4.3 and 7.5 fg (21, 36 and 1.1 µBq), respectively. We analyzed five international standard materials for Pu, and obtained good results.
    Download PDF (78K)
  • Wagner J. BARRETO, Maira R. RIBEIRO, Maria C. SOLCI, Ieda S. SCARMINIO ...
    2005 Volume 21 Issue 3 Pages 209-214
    Published: 2005
    Released: June 14, 2005
    JOURNALS FREE ACCESS
    The hydrological cycle of Lake Ipê and the principal parameters that could affect its abiotic parameters and its metal (Fe, Mn, and Cd) concentrations were investigated. A detailed study of seasonal variations using Principal Components Analysis (PCA) for the most relevant metals (Fe, Mn and Cd) was performed, assisted by the MINTEQA2 geochemical equilibrium program using 15 water abiotic parameters. The abiotic variables and metals in the lake were governed by the hydrological regimen of the Parana River and by the occurrence of occasional flood pulses and rainfall. The occurrence of cadmium is a concern; its presence could be due to industrial or agricultural activities or even to a natural geochemical process.
    Download PDF (210K)
  • Keiichi OHTSUKA, Masahide KUROKI, Takahiko NOJIMA, Michinori WAKI, Shi ...
    2005 Volume 21 Issue 3 Pages 215-218
    Published: 2005
    Released: June 14, 2005
    JOURNALS FREE ACCESS
    A monoclonal antibody for the carcinoembryonic antigen (CEA) was immobilized on a gold chip surface covered by a self-assembled monolayer of 11-mercaptoundecanoic acid. Upon the addition of CEA, a Fourier transform infrared reflection-absorption spectroscopy (FT-IR RAS) measurement showed an increased absorption at around 1500 - 1700 cm-1, corresponding to its amide structures. Another addition of CEA polyclonal antibody on this chip caused a further increase of the absorption in this region only after a treatment with CEA. This result shows that an antibody-fixed gold surface coupled with an FT-IR RAS measurement provides a new tool for detecting the antibody-antigen interaction.
    Download PDF (127K)
  • Yuko MATSUMOTO, Hideki KURAMITZ, Shinji ITOH, Shunitz TANAKA
    2005 Volume 21 Issue 3 Pages 219-224
    Published: 2005
    Released: June 14, 2005
    JOURNALS FREE ACCESS
    A sensitive and simple immunoassay to determine 17β-estradiol (E2) in fresh water was developed. The method is based on a solid-phase avidin-biotin binding assay and solid phase extraction. The binding event of E2 to the antibody is detected indirectly by the competitive reaction between E2 and biotinylated estradiol (BE) as a tracer for the limited binding sites of antibodies immobilized onto the wall of a microtiter plate. Namely, E2 concentrations are determined from the strong interaction between BE and avidin conjugated with horseradish peroxidase (avidin-HRP). In order to achieve a sensitive measurement for the binding of BE to the antibody immobilized on the microtiter plate substrate, QuantaBlu™ fluorogenic peroxidase substrate (QFPS) was employed. The detection limit and the linear range of E2 determination were 27 pM and 27 - 7480 pM, respectively. The relative standard deviations (RSD) for the E2 assay were between 0.3 and 12.0% (n = 3). The cross-reactivities of several other estrogens in this assay system were also investigated. No serious influences from any cross-reaction caused by other estrogens tested in this experiment were observed. The determination of E2 in water samples from eight rivers and a marsh in Hokkaido was performed by the immunoassay combined with solid phase extraction. It was found that the concentration of E2 was in the range between 0.06 and 67 pM.
    Download PDF (115K)
  • Wei-Chang TSENG, Yuh-Chang SUN, Cheng-Fa LEE, Mo-Hsiung YANG, Yeou-Lih ...
    2005 Volume 21 Issue 3 Pages 225-229
    Published: 2005
    Released: June 14, 2005
    JOURNALS FREE ACCESS
    A direct, rapid and continuous in vivo monitoring of diffusible calcium in the blood of living rabbits has been developed using microdialysis sampling coupled on-line with flame atomic absorption spectrometry. Microdialysates perfused through implanted microdialysis probes were collected with a sample loop on an injection valve and directly introduced into the flame atomizer by a carrier solution. An ultrapure saline solution (0.9% NaCl, pH 7.2) was used as the perfusion solution at a flow rate of 20 µl min-1 via the microdialysis probe. A 0.1% La solution in 0.5% HNO3 solution was employed as the carrier solution at a nebulizer uptake flow rate of 2.5 ml min-1. The interval for each determination was 2.5 min (2 min of sampling time, 20 s of read time and 10 s of washing time). The performance characteristics of the on-line microdialysis-FAAS system were validated as follows: linearity range, 0 - 100 mg l-1; detection limit (3 σ, n = 7), 3.66 mg l-1; precision (RSD, n = 50), 6.2%. For the evaluation of analytical accuracy, the proposed on-line method was compared with the in vivo no net flux method. The use of an on-line microdialysis-FAAS system permitted the in situ, dynamic and continuous in vivo monitoring of diffusible calcium in the blood of the living rabbits after CaCl2 administration with a temporal resolution of 2.5 min.
    Download PDF (106K)
  • Faju HOU, Xiaolei WANG, Chongqiu JIANG
    2005 Volume 21 Issue 3 Pages 231-234
    Published: 2005
    Released: June 14, 2005
    JOURNALS FREE ACCESS
    A new spectrofluorimetric method has been developed for the determination of adenosine disodium triphosphate (ATP). We studied the interactions between the doxycycline (DC)-Eu3+ complex and adenosine disodium triphosphate (ATP) by using UV-visible absorption and fluorescence spectra. Using doxycycline (DC)-Eu3+ as a fluorescence probe, under the optimum conditions, ATP could remarkably enhance the fluorescence intensity of the DC-Eu3+ complex at λ = 612 nm. The enhanced fluorescence intensity of the Eu3+ ion was in proportion to the concentration of ATP. The optimum conditions for the determination of ATP were also investigated. The linear ranges for ATP were 1.00 × 10-7 - 2.00 × 10-6 mol L-1 with detection limits of 4.07 × 10-8 mol L-1. This method is simple, practical and relatively free of interference from coexisting substances, and can be successfully applied to the determination of ATP in samples. The mechanism of fluorescence enhancement between the doxycycline (DC)-Eu3+ complex and ATP was also studied.
    Download PDF (90K)
  • Audrey A. S. G. LONNI, Ieda S. SCARMINIO, Lucas M. C. SILVA, Dalva T. ...
    2005 Volume 21 Issue 3 Pages 235-239
    Published: 2005
    Released: June 14, 2005
    JOURNALS FREE ACCESS
    Numerical taxonomy characterization of Baccharis genus species was performed using ultraviolet-visible spectrophotometry. The aim was to present a more convenient, more practical, more economic and faster method based on chemometric methods and UV-vis absorbance to give the most information about species identity and discrimination, especially when their classification has been doubtful. Three Baccharis species: B. genistelloides Persoon var. trimera (Less.) DC, B. milleflora (Less.) DC, and B. articulata (Lam.) Persoon were included in the study. With the help of principal component analysis (PCA) and cluster analysis (CA), we could characterize the three species. Application of soft independent modeling of class analogy (SIMCA) and K-nearest neighbor (KNN) methods on a training set of 65 extracts resulted in models that correctly classified all samples of an independent validation set, eight samples of B. genistelloides Persoon var. trimera (Less.) DC and one sample donated by Prof. Alarich Schultz Herbarium, Porto Alegre-RS, Brazil.
    Download PDF (85K)
  • Thiraporn CHAROENRAKS, Suchada CHUANUWATANAKUL, Kensuke HONDA, Yoko YA ...
    2005 Volume 21 Issue 3 Pages 241-245
    Published: 2005
    Released: June 14, 2005
    JOURNALS FREE ACCESS
    The analysis of tetracycline, oxytetracyline, chlortetracycline and doxycycline by high-performance liquid chromatography with pulsed amperometric detection using an anodized boron-doped diamond thin film (BDD) electrode is originally reported. The analyses were carried out using the mobile phase, phosphate buffer (0.01 M, pH 2.5)-acetonitrile (80:20; v/v), on a C18 column (250 × 4.6 mm i.d., 5 µm) at a flow rate of 1.0 mL/min. The optimal PAD waveform parameters at the anodized BDD were 1.5 V (versus Ag/AgCl) detection potential (Edet) for 290 ms (200 ms delay time and 90 ms integration time), 2.0 V (versus Ag/AgCl) oxidation potential (Eoxd) for 200 ms oxidation time (toxd) and 0.4 V (versus Ag/AgCl) reduction potential (Ered) for 200 ms reduction time (tred). The proposed method showed the simultaneous determination of tetracycline, oxytetracyline, chlortetracycline and doxycycline with a linear range of 0.1 - 100 µg/mL, detection limits of 0.05 - 0.1 µg/mL and recoveries of 70.8 - 96.0%. The application of this method to real samples was demonstrated and validated using a shrimp sample.
    Download PDF (75K)
  • Gang CHEN, Luyan ZHANG, Pengyuan YANG
    2005 Volume 21 Issue 3 Pages 247-251
    Published: 2005
    Released: June 14, 2005
    JOURNALS FREE ACCESS
    A method based on capillary electrophoresis with electrochemical detection has been developed for the separation and determination of paeoniflorin, sucrose, glucose, and fructose in traditional Chinese medicine, Radix Paeoniae Alba. The effects of several important factors, such as the concentration of NaOH, the separation voltage, the injection time, and the detection potential, were investigated to determine the optimum conditions. The detection electrode was a 300-µm diameter copper disc electrode at a working potential of +0.60 V (versus SCE). The four analytes can be well separated within 8 min in a 40 cm length fused-silica capillary at a separation voltage of 12 kV in a 75 mM NaOH aqueous solution. The relation between the peak current and the analyte concentration was linear over about 3 orders of magnitude with detection limits (S/N = 3) ranging from 1 to 2 µM for all analytes. The proposed method has been successfully applied for the determination of the paeoniflorin and sugars in real plant samples with satisfactory assay results.
    Download PDF (80K)
  • Xiaojia HUANG, Junde WANG, Qiuquan WANG, Benli HUANG
    2005 Volume 21 Issue 3 Pages 253-257
    Published: 2005
    Released: June 14, 2005
    JOURNALS FREE ACCESS
    A new type of chiral ligand-exchange stationary phase (CLES) was successfully synthesized by treating silica gel with β-(3,4-epoxycyclohexyl)ethyltrimethoxy silane and opening the epoxy ring by L-isoleucine. The chiral speciation of DL-selenomethionine (DL-SeMet) by high-performance liquid chromatography (HPLC) with UV absorbance on the CLES column was studied. The influences of the contents of copper ion and methanol as well as the pH value in the mobile phase and temperature of the column on the efficiency of resolution of DL-SeMet were investigated in detail. DL-SeMet could be completely resolved within 40 min under the optimal operating conditions of 0.1 mmol/L Cu2+ at 0.05 mol/L KH2PO4 buffer (pH = 5.5) and 35°C temperature of the column. The limits of detection of D- and L-SeMet were 255 ppb and 286 ppb, respectively. This method was applied to determine the D- and L-enantiomers of DL-SeMet in real samples, such as selenized yeast powder and garlic.
    Download PDF (94K)
  • Jingdong PENG, Shaopu LIU, Chuanyue DENG
    2005 Volume 21 Issue 3 Pages 259-262
    Published: 2005
    Released: June 14, 2005
    JOURNALS FREE ACCESS
    An RP-HPLC method for the separation and determination of aluminium(III), vanadium(V), iron(III), copper(II) and nickel(II) with CALKS (Chromazol KS) and PAR ([4-(2-pyridylazo)resorcinol]) chelating on a YWG-ODS column was developed. A mixture of methanol-tetrahydrofuran(THF)-water (60:5:35 v/v) containing 0.2 mol/L LiCl, 5 × 10-5 mol/L CALKS, 5 × 10-5 mol/L PAR and acetate buffer solution (pH 4.9) was selected as mobile phase. The method has high sensitivity, with the detection limits being 6 ng/mL for aluminium(III), 3.5 ng/mL for vanadium(V), 10.4 ng/mL for iron(III), 6.3 ng/mL for copper(II) and 8.7 ng/mL for nickel(II). It also has good selectivity, so that most foreign metal ions do not interfere under the optimum conditions. The method can be applied to the simultaneous determination of trace amounts of aluminium, vanadium, iron, copper and nickel in rice and flour samples.
    Download PDF (106K)
  • Zenhai LI, Mitsuko OSHIMA, Akhmad SABARUDIN, Shoji MOTOMIZU
    2005 Volume 21 Issue 3 Pages 263-268
    Published: 2005
    Released: June 14, 2005
    JOURNALS FREE ACCESS
    A highly sensitive fluorescence-quenching method for the determination of phosphorus based on the formation of an ion associate between molybdophosphate and Rhodamine B (RB) was developed. A simple flow-injection system coupled with a fluorescence detector was used to measure the fluorescence intensity at 560 nm and 580 nm as an excitation and an emission wavelength, respectively. The calibration graph for phosphorus showed a good linearity in the range of (0 - 1) × 10-7 M (1 M = 1 mol L-1), and a detection limit of 1 × 10-9 M (S/N = 3). The proposed method was successfully applied to the determination of ultratrace amounts of phosphorus in ultrapurified and purified water samples, and to the determination of trace amounts of phosphorus in commercially-available hydrogen peroxide solutions with satisfactory results.
    Download PDF (88K)
  • Minako IWAKUMA, Yoshinari BABA
    2005 Volume 21 Issue 3 Pages 269-272
    Published: 2005
    Released: June 14, 2005
    JOURNALS FREE ACCESS
    2-Dodecylthiomethylpyridine (DTP) was newly synthesized to study its extraction properties for precious metals. DTP was a selective extractant for palladium(II) and gold(III) over base metals. The loading test for palladium(II) showed that one palladium ion reacted with one molecule of DTP. The extraction rate of palladium with DTP was measured using a Lewis-type transfer cell at 303 K. The extraction reaction of palladium with DTP has been found to be a first order reaction with respect to palladium ion, DTP, and hydrogen ion concentrations. This reaction is inversely proportional to chloride ion concentration. The rate-determining step was the parallel reactions of DTP with PdCl3- and PdCl42- in the aqueous phase.
    Download PDF (79K)
  • Yong-Sheng LI, Cheng-Xia XING, Li-Ling YANG
    2005 Volume 21 Issue 3 Pages 273-279
    Published: 2005
    Released: June 14, 2005
    JOURNALS FREE ACCESS
    A new method for the rapid determination of trace-level sodium ion based on flow-injection analysis (FIA) and an ion selective electrode (ISE) is proposed. Various effects on the sensitivity of the method such as the flow rate and alkalinity of the carrier, sampling volume, temperature, length of reaction coil, length and thickness of alkalization tube, concentration of the alkalizing reagent etc. were investigated. The optimum conditions were ascertained. The method showed good linearity in the concentration ranges of 0.5 - 10 µg L-1 and 10 - 100 µg L-1, and could deal with 40 - 50 samples per hour. The consumption of the sample is only 0.80 mL per time. The relative standard deviation was 0.55%, and the recovery range was 98 - 103%. By designing a hermetically sealed single-line FIA-ISE manifold, a problem removing the interference of sodium ion from air could be solved, and automatic alkalization of the sample was realized. This method has been used for successfully determining the trace-level sodium ions in the water-steam system at fossil power plants.
    Download PDF (163K)
  • Chikaaki MIZUNO, Shanhu BAO, Teruo HINOUE, Toshiaki NOMURA
    2005 Volume 21 Issue 3 Pages 281-286
    Published: 2005
    Released: June 14, 2005
    JOURNALS FREE ACCESS
    The interaction between metal ions and bovine serum albumin (BSA) was studied by using a piezoelectric quartz crystal (PQC) arranged in the electrode-separated configuration. A silanized surface of the PQC was coated with a BSA membrane via a coupling reaction with glutaraldehyde. The frequency shifts obtained from PQC coated with a BSA membrane suggested that various kinds of metal ions could be adsorbed onto the BSA membrane from aqueous solutions containing a low concentration of metal ions (2 or 10 µmol dm-3), only when the BSA was denatured with an alkaline solution. Anionic species of Pt(IV) and Au(III) were adsorbed onto the denatured BSA membrane from an acetic acid solution at pH 2.2, and cationic species of Cd(II), Zn(II), Co(II), Ni(II), Cu(II), and Ag(I), and cations, such as Ca2+, Ba2+, and Mg2+, were adsorbed from ammonia buffer at pH 9.5, whereas Al(III), Cr(III), Fe(III), Hg(II), and Pb(II) were hardly adsorbed. The adsorption mechanisms of these metal ions are discussed, based on the electrostatic interaction between the metal ions and the denatured BSA membrane, and complex formation between the metal ions and amino acid residues of the denatured BSA. Further, the PQC coated with a denatured BSA membrane was applied to the determination of Pt and Cd, using large frequency shifts for Pt(IV) and Cd(II).
    Download PDF (96K)
  • Lan XU, Ruo YUAN, Ying-Zi FU, Ya-Qin CHAI
    2005 Volume 21 Issue 3 Pages 287-292
    Published: 2005
    Released: June 14, 2005
    JOURNALS FREE ACCESS
    A novel salicylate-selective electrode based on an organotin complex with a salicylal Schiff base of amino acid salicylaldehydeaminoacid-di-n-butyl-Sn(IV) [Sn(IV)-SAADB] as ionophore is described, which exhibits high selectivity for salicylate over many other common anions with an anti-Hofmeister selectivity sequence: Sal- » PhCOO-> SCN- > ClO4- > I- > NO3- > NO2- > Br- > Cl- > CH3COO-. The electrode, based on Sn(IV)-SAADB, with a 30.44 wt% PVC, a 65.45 wt% plasticizer (dioctyl phthalate, DOP), a 3.81 wt% ionophore and a 0.3 wt% anionic additive is linear in 6.0 × 10-6 - 1.0 × 10-1 mol l-1 with a detection limit of 2.0 × 10-6 mol l-1 and a slope of 62.0 ± 1.2 mV/decade of salicylate concentration in a phosphate buffer solution of pH 5.5 at 25°C. The influence on the electrode performances by lipophilic charged additives was studied, and the possible response mechanism was investigated by UV spectra. The electrode was applied to medicine analysis and the result obtained has been satisfactory.
    Download PDF (105K)
  • Vinod Kumar GUPTA, Rainer LUDWIG, Shiva AGARWAL
    2005 Volume 21 Issue 3 Pages 293-296
    Published: 2005
    Released: June 14, 2005
    JOURNALS FREE ACCESS
    5,11,17,23,29,35-Hexakis(1,1,3,3-tetramethylbutyl)-37,38,39,40,41,42-hexakis(carboxy methoxy)calix[6]arene (I) has been evaluated as an ionophore for the analysis of Sr2+. The influences of the nature of the plasticizers (DBA, CN, DOP, NPOE) and of the anion excluder (NaTPB) on the characteristics of the electrode were discussed. The best electrode was fabricated with a membrane having composition 6:150:170:3 (I:PVC:DBA:NaTPB). The response to Sr2+ was Nernstian in the range 1.9 × 10-5 to 1.0 × 10-1 M of Sr2+. The influence of pH has also been studied. The electrode exhibited better potential stability and had an operational lifetime of 4 months. The KA,BPot values showed that other alkaline earth metal ions are well discriminated. The sensor has also been used as an indicator electrode in the potentiometric titration of sodium carbonate with strontium(II) ions.
    Download PDF (69K)
  • Golamreza KHAYATIAN, Hadi REZATABAR, Abdollah SALIMI
    2005 Volume 21 Issue 3 Pages 297-302
    Published: 2005
    Released: June 14, 2005
    JOURNALS FREE ACCESS
    A new PVC membrane electrode for the triiodide ion based on a charge-transfer complex of iodine with 7,16-dibenzyl-1,4,10,13-tetraoxa-7,16-diazacyclooctadecane as a membrane carrier was prepared. The electrode exhibits a Nernstian response for triiodide ions over a wide concentration range (1.0 × 10-1 - 1.0 × 10-5 M) with a slope of 59.3 ± 0.9 mV decade-1 and a detection limit of 6.3 × 10-6 M. It has a response time of 30 s and can be used for at least 3 months without any divergence in the potential. The potentiometric response is independent of the pH, in the pH range 1.6 - 10.0. The proposed electrode has shown very high selectivity for the triiodide ion over a wide variety of other anions. This electrode was successfully applied as an indicator electrode in the potentiometric titration of ascorbic acid and hydroquinone from pharmaceutical preparations as well as ascorbic acid in orange juice and dissolved O2 in tap water.
    Download PDF (89K)
  • Yasuyuki TSUBOI, Kensaku OKADA, Shoji ISHIZAKA, Noboru KITAMURA
    2005 Volume 21 Issue 3 Pages 303-308
    Published: 2005
    Released: June 14, 2005
    JOURNALS FREE ACCESS
    We found that α-diketones (2,3-butanedione (BD) and 1-phenyl-1,2-propanedione (PPD)) were very suitable luminescence probes for studying the properties of a perfluorinated solvent (i.e., fluorous solvent; perfluoromethylcyclohexane (PFMC)), since these compounds were soluble in PFMC and showed long-lived phosphorescence even at room temperature. The phosphorescence lifetime (τp) of BD in PFMC (650 µs) was much longer than that in cyclohexane (CH, 270 µs). The longer τp value of BD in PFMC was ascribed to the variation of the intersystem crossing rate constant (kisc) from the excited triplet state (T1) to the ground state (S0) with the solvent. Some possible reasons for the change in kisc were discussed in terms of solute-solvent interactions. Furthermore, by utilizing phosphorescence quenching of BD by pyrene, we determined a rate constant of the diffusion-controlled reaction in PFMC. Characteristic behaviors of mixing/separation processes between PFMC and a common organic solvent observed by Schlieren photographs were also reported.
    Download PDF (740K)
  • Hisao YAMASHIGE, Shuji MATSUO, Tsutomu KURISAKI, Rupert C. C. PERERA, ...
    2005 Volume 21 Issue 3 Pages 309-314
    Published: 2005
    Released: June 14, 2005
    JOURNALS FREE ACCESS
    X-ray absorption near edge structure (XANES) measurements at the C, N, and Fe K absorption edges were performed for iron(III)-tetraphenylporphyrin (FeTPP), iron(III)-tetrakis(p-carboxyphenyl)porphyrin (FeTCPP), and iron(III)-tetrakis(p-sulfonatophenyl)porphyrin (FeTSPP). The spectral shapes differ in the Fe K XANES, but not in C and N K XANES among FeTPP, FeTCPP, and FeTSPP. Crosschecks of XANES data for C, N, and Fe K absorption edges in combination with discrete variational (DV)-Xα molecular orbital (MO) calculations indicate that each p-electron-withdrawing group on four meso-phenyl substitutes in an Fe(III)-porphyrin complex brings about a unique electron state through the complex because of the electron-withdrawal strength, itself. Consequently, they affect the positive charge of the center Fe(III) ion.
    Download PDF (124K)
  • Hiroki KIMOTO, Atsuko FUKUDA, Atsushi ASANO, Takuzo KUROTSU
    2005 Volume 21 Issue 3 Pages 315-319
    Published: 2005
    Released: June 14, 2005
    JOURNALS FREE ACCESS
    The proton spin-spin relaxation time (T2) during the bulk polymerization of methyl acrylate was measured as a function of the reaction time at various temperatures. Three kinds of T2 (T2L (long), T2S (short) and T2M (intermediate)) were obtained as the polymerization proceeded. The fraction of T2S (FS) increased sigmoidally at a certain reaction time, while that of T2L (FL) decreased reciprocally. The former corresponded to the amount of a polymer whose molecular weight was sufficiently high enough to cause a tight entanglement that produced a transient network structure; the latter reflected a decrease in the mixture of the monomer and the low molecular weight of the polymer. T2M is considered to arise from a relatively mobile region of the entanglement. The relationship between the fractions of T2S + T2M and the polymer yield was found to be linear, which led us to monitor the polymer yield in real time during the polymerization in a non-distractive manner. 13C DD (dipolar decoupling)/MAS (magic angle spinning) NMR spectra were also measured to monitor the polymerization process in terms of the molecular motions between the main chain and the side chain in the formation of a network structure. The 13C DD/MAS NMR spectra show that the side chain motion became restricted as well as the main chain when the “Trommosdorff effect” (gel effect) was observed, and a part of the monomers were trapped in the network structure.
    Download PDF (110K)
  • Tomohiro KYOTANI, Kiminori SATO, Takehito MIZUNO, Sonoko KAKUI, Masano ...
    2005 Volume 21 Issue 3 Pages 321-325
    Published: 2005
    Released: June 14, 2005
    JOURNALS FREE ACCESS
    A zeolite NaA (LTA) membrane supported by an alumina porous support tube was characterized by Fourier Transform Infrared Attenuated Total Reflectance method (FTIR-ATR) with a diamond prism as the waveguide. A method using the FTIR-ATR was developed to estimate rapidly the EtOH/H2O pervaporation (PV) performance of the membrane. The Si-O asymmetric stretching vibration region of LTA membrane spectra synthesized hydrothermally on seeded alumina substrates showed a bimodal peak (830 - 1200 cm-1). The two peaks were assigned to a surface LTA directly derived from the seed crystal (1012 cm-1), and to LTA and/or amorphous substances embedded in the alumina porous support (930 cm-1). The spectrum from LTA membrane synthesized on nonseeded alumina substrate, however, showed a single broad peak similar to the powder-formed one. These results indicate that the Si-O spectral shape of the LTA membrane is influenced strongly by the synthesis method. Also, the FTIR-ATR of the LTA membrane can detect the Si-O peaks as part of the depth information. It was first shown that the relative ratio (930 cm-1/1012 cm-1) of the two Si-O peaks from the LTA membranes on seeded alumina substrates closely relates to the water selectivity (α) in the PV of EtOH/H2O mixture; the α increases exponentially with the peak ratio. This result suggests that the differences in the vertical distribution of LTA crystal and amorphous material strongly affect the dehydration performance in the EtOH/H2O PV, that is, the amorphous-like material embedded in the alumina porous support plays an important role. The relative peak ratio measurement can be used for the rapid evaluation of the dehydration performance of the membrane.
    Download PDF (158K)
  • Ya-Ping DING, Qing-Sheng WU, Qing-De SU
    2005 Volume 21 Issue 3 Pages 327-330
    Published: 2005
    Released: June 14, 2005
    JOURNALS FREE ACCESS
    A new biomimetic algorithm, Chemical Ant Colony Algorithm, has been developed, which has the characteristics of intelligent search, global optimization, robustness, distributed computation and easy combination with other heuristic. The proposed method has been successfully applied to the spectroscopy analysis of the Zn2+, Cd2+, Pb2+-porphyin tribasic color system with supramolecular properties; the errors are within ±8.0%.
    Download PDF (104K)
  • Kazuishi SATO, Toshinori KOIZUMI, Kunihiko OKAJIMA
    2005 Volume 21 Issue 3 Pages 331-335
    Published: 2005
    Released: June 14, 2005
    JOURNALS FREE ACCESS
    The thermally stimulated depolarized current and temperature profiles (TSDC analysis) on iced water was proved to be an effective tool for the qualitative evaluation of various water samples, each having an independent relaxation process, brought about by a pure dipolar orientation. The method proved to be applicable to different kinds of water samples used in the experiment and tap-water samples from different suppliers. Five main peaks (A to E, in the order of increasing temperature) were observed, of which two peaks (B and D) were found for the first time. The appearance of multiple peaks suggested the existence of multi-states of the hydrogen bond, cleaved by the TSDC process. The TSDC profiles were quite reproducible when the water samples contained practically no cations. A separate addition of each cation at a low concentration level revealed that a cation with a smaller ionic radius shifted peak A to a higher temperature. For ice of tap water, which contained relatively higher amount of cations, the TSDC profiles were quite different in shape compared with the standard ice-water samples (shift of peaks A - D to higher temperature, and a strong increase in the current strength of peaks B - E). However, it was still possible to tell from which districts the water samples were supplied.
    Download PDF (116K)
Notes
Announcements
feedback
Top