Analytical Sciences
Online ISSN : 1348-2246
Print ISSN : 0910-6340
ISSN-L : 0910-6340
Volume 29 , Issue 1
Showing 1-32 articles out of 32 articles from the selected issue
Original Papers
  • Wesley W. HSIAO, Hsien-Shun LIAO, Hsing-Hung LIN, Ren-Feng DING, Kuang ...
    Type: Original Papers
    2013 Volume 29 Issue 1 Pages 3-8
    Published: January 10, 2013
    Released: January 10, 2013
    JOURNALS FREE ACCESS
    Eukaryotic flagella are responsible for the motile organelles that cause the migration of mammalian sperms. The lashing force and torque of the sperm flagellum contain critical information regarding the sperm health, as important evaluation factors for sperm screening. The objective of the study was to investigate the lashing force and torque of a sperm under physiological conditions using atomic force microscopy (AFM). At a distance of about 18.5 μm from its head-tail junction, a lashing force of 0.96 ± 0.20 nN was measured. Its corresponding lashing torque was 1.77(± 0.37)× 10−14 N·m. The torque increases in proportion to the square of the head-tail junction distance. Our results reasonably conclude that the axonemal motility is linear dependent on the flagellum length of the sperm. Our developed measurement system can consistently determine the lashing force and torque of a sperm, which can contribute to further studies concerning the mechanism of sperm transport and fertilization.
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  • Takuroh NOGUCHI, Mayumi HATTA, Toshiro YAMANAKA, Kei OKAMURA
    Type: Original Papers
    2013 Volume 29 Issue 1 Pages 9-13
    Published: January 10, 2013
    Released: January 10, 2013
    JOURNALS FREE ACCESS
    We developed a system for measuring the total dissolved inorganic carbon (DIC) concentrations in interstitial water and hydrothermal fluid, which are hard to obtain in large volumes. The system requires a sample volume of only 500 μL, and it takes only 150 s per one sample. The detection limit of this system was estimated to be 66.6 μmol/kg with repeated analysis of CO2-free ultrapure water (n = 9). The precision of this nondispersive infrared (NDIR) system was ±3.1% of the relative standard deviations (2σ) by repeated CRM batch 104 (n = 10). This result is much larger than the required precision for oceanographic studies, but is comparable to a previous result of interstitial water analysis. An on-site trial showed a significant DIC enrichment in interstitial water of hydrothermally altered sediment, and is considered to occur by the mixing of hydrothermal fluid. This procedure will achieve carbon dioxide flux calculations from hydrothermal activities, and will bring a more accurate feature on the global carbon cycle.
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  • Yusuke SATO, Tomoe KAGEYAMA, Seiichi NISHIZAWA, Norio TERAMAE
    Type: Original Papers
    2013 Volume 29 Issue 1 Pages 15-19
    Published: January 10, 2013
    Released: January 10, 2013
    JOURNALS FREE ACCESS
    We describe a competitive binding assay for the analysis of single-base mutation by using abasic site (AP site)-specific binding fluorescent ligands and masking ligands bound to the AP site in DNA duplexes. 2-Amino-5,6,7-trimethyl-1,8-naphthyridine (ATMND) can strongly bind to not only cytosine (C), but also thymine (T) opposite an AP site in the DNA duplexes (K11/107 M−1: C, 15; T, 7.0). By contrast, in the presence of lumichrome (Lch) as a masking ligand, ATMND shows a clear binding selectivity for C over T (K11/107 M−1: C, 7.0; T, 0.57), which is ascribed to the effective masking effect of Lch to the ATMND-T interaction in the AP site-containing DNA duplexes. It was shown that the competitive binding of ATMND and Lch to the AP site allowed the highly selective detection of C-related single-base mutation in DNAs amplified by polymerase chain reaction.
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  • Megumi NAGAI, Wakayo MIYAHARA, Honami SAGAWA, Shigeo YAMAZAKI, Keiitsu ...
    Type: Original Papers
    2013 Volume 29 Issue 1 Pages 21-24
    Published: January 10, 2013
    Released: January 10, 2013
    JOURNALS FREE ACCESS
    A chemiluminescence method for the determination of glucose (GC) using a batch system made in our laboratory is proposed. The method is based on measures of the chemiluminesence intensity from a batch of sample GC solutions following the injection of an (NH4)2[Ce(NO3)6]–[Ru(bpy)3]Cl2 solution. The effect of the Ru complex concentration on chemiluminescence was studied. The detection limit was 0.5 × 10−8 M, and the linear calibration curve reached 10−7 M. The Ru complex was selected on the basis of its desirable performance compared to those of other photosensitizers. However, flow-injection analysis (FIA) using the Ce-Ru complex reagent was not applicable for the detection of GC.
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  • Kohei UEMATSU, Hajime KATANO
    Type: Original Papers
    2013 Volume 29 Issue 1 Pages 25-29
    Published: January 10, 2013
    Released: January 10, 2013
    JOURNALS FREE ACCESS
    An approximate equation for bioelectrocatalitic current was applied to an inhibition reaction analysis of bilirubin oxidase by anion (Cl, SCN, and F) in order to assess the possibility of the electrochemical method for the analysis of enzymatic inhibition reactions. The approximate equation can be transformed into the Michaelis–Menten form, so that the bioelectrocatalitic current can be analyzed by the usual graphical manner, that is, Lineweaver–Burk, Hanes–Woolf, Dixon and Cornish–Bowden plots, if the rate of inhibition reaction is described as a simple Michaelis–Menten form. From the electrochemical assay, it was found that the inhibitor of Cl and SCN anions exhibit non-competitive inhibition while that of F exhibits competitive inhibition, and their inhibition constants were 220, 45, and 22 mM, respectively. The results were essentially similar to those obtained from the conventional spectrophotometric assay.
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  • Li RONG, Lee Wah LIM, Toyohide TAKEUCHI
    Type: Original Papers
    2013 Volume 29 Issue 1 Pages 31-34
    Published: January 10, 2013
    Released: January 10, 2013
    JOURNALS FREE ACCESS
    A novel and simple capillary ion chromatographic method for the determination of iodide is reported. Separation was achieved on a laboratory-made packed capillary column (100 mm × 0.32 mm i.d.) packed with triacontyl-functionalized silica, followed by a modification with hexadimethrine bromide, where 1 mM sodium chloride–acetonitrile (95:5, v/v) was used as the eluent and UV-absorbing analyte anions were detected at 225 nm. The effects of the eluent composition on the retention behavior of inorganic anions were investigated. The addition of a small amount of an organic substance in an eluent such as acetonitrile increased the retention of iodide, while the addition of methanol decreased its retention. The present analytical method was successfully applied to the rapid and direct determination of iodide in seawater without any preconcentration. Also, this modified column could be used for about two months (6 h operation per day) without hexadimethrine bromide being contained in the eluent.
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  • Yoshinori IIGUNI, Hajime OHTANI
    Type: Original Papers
    2013 Volume 29 Issue 1 Pages 35-39
    Published: January 10, 2013
    Released: January 10, 2013
    JOURNALS FREE ACCESS
    By using the electromagnetophoretic migration technique with permanent magnets, the electromagnetophoretic migration velocimetry in a droplet-based system was demonstrated for organic droplets dispersed in an aqueous solution. Migration of 2-fluorotoluene droplets with a diameter of 8 – 16 μm dispersed in 1.0 M KCl aqueous solution could be achieved in the same manner as for solid particles. The effect of cetyltrimethylammonium bromide (CTAB) on the electromagnetophoretic migration velocity of the droplets was also investigated. When the concentration of CTAB was in the range from 10−6 to 10−4 M, the electromagnetophoretic migration velocity of 2-fluorotoluene droplets decreased as the concentration of CTAB increased. With this measurement, we could successfully characterize organic droplets in terms of the amount of adsorbing surfactants by evaluating the surface conductivity of organic droplets calculated based on their electromagnetophoretic migration velocity.
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  • Shinya YAMASAKI, Shuto YAMADA, Kô TAKEHARA
    Type: Original Papers
    2013 Volume 29 Issue 1 Pages 41-46
    Published: January 10, 2013
    Released: January 10, 2013
    JOURNALS FREE ACCESS
    The inhibitory effects of hydrophobic molecules on the bacterial luciferase, BL, luminescence reaction were analyzed using an electrochemically-controlled BL luminescence system. The inhibition potency of alkyl amines, CnNH2, and fatty acids, CmCOOH (m = n – 1), on the BL reaction increased with an increase in the alkyl chain-length of these aliphatic compounds. CmCOOH showed lower inhibition potency than CnNH2 and alkyl alcohols, CnOH, data for which have been previously reported. To make clear the inhibition mechanisms of the aliphatic compounds on the BL reaction, the initial rate of the BL reaction was measured and analyzed using the Dixon plot and Cornish–Bowden plot. The C12OH inhibited the BL reaction in competition with the substrate C11CHO, while C12NH2 and C11COOH inhibited in an uncompetitive manner with the C11CHO. These results suggest that the alkyl chain-length and the terminal unit of the aliphatic compound determine the inhibition potency and the inhibition mechanism, respectively.
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  • Takeshi OHNO, Takafumi HIRATA
    Type: Original Papers
    2013 Volume 29 Issue 1 Pages 47-53
    Published: January 10, 2013
    Released: January 10, 2013
    JOURNALS FREE ACCESS
    We have developed a new analytical method to determine the mass-dependent isotopic fractionations on Ce and Nd in geochemical samples. Mass discrimination effects on Ce and Nd were externally corrected by normalizing 149Sm/147Sm and 153Eu/151Eu, being 0.92124 and 1.0916, respectively based on an exponential law. The reproducibility of the isotopic ratio measurements on 142Ce/140Ce, 146Nd/144Nd and 148Nd/144Nd were 0.08‰ (2SD, n = 25), 0.06‰ (2SD, n = 39) and 0.12‰ (2SD, n = 39), respectively. The present technique was applied to determine the variations of the Ce and Nd isotopic ratios for five geochemical reference materials (igneous rocks, JB-1a and JA-2; sedimentary rocks, JMn-1, JCh-1 and JDo-1). The resulting ratios for two igneous rocks (JB-1a and JA-2) and two sedimentary rocks (JMn-1 and JCh-1) did not vary significantly among the samples, whereas the Ce and Nd isotope ratios for the carbonate samples (JDo-1) were significantly higher than those for igneous and sedimentary rock samples. The 1:1 simple correlation between δ142Ce and δ146Nd indicates that there were no significant difference in the degree of isotopic fractionation between the Ce and Nd. This suggests that the isotopic fractionation for Ce found in the JDo-1 could be induced by geochemical or physicochemical processes without changing the oxidation status of Ce, since the redox-reaction can produce larger isotopic fractionation than the reactions without changing the oxidation state. The variations in the Ce and Nd isotope ratios for geochemical samples could provide new information concerning the physico-chemical processes of the sample formation.
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  • Yuko UENO, Kazuaki FURUKAWA, Katsuyoshi HAYASHI, Makoto TAKAMURA, Hiro ...
    Type: Original Papers
    2013 Volume 29 Issue 1 Pages 55-60
    Published: January 10, 2013
    Released: January 10, 2013
    JOURNALS FREE ACCESS
    We have developed a new procedure for fabricating interdigitated array gold electrodes (Au-IDA) modified with reduced graphene oxide (rGO). In this procedure, we coated the gold surface of the micrometer order electrodes with graphene oxide (GO) prior to the reduction and the lift-off processes to avoid short-circuiting the pair of electrodes by conductive rGO flakes after the reduction. We then studied the basic electrochemical activity of the prepared electrodes, rGO/Au-IDA, mainly on p-aminophenol (pAP), because pAP is a good probe for an electrochemical immunoassay. The voltammograms showed that denser rGO provides better electrode reactivity for pAP. We confirmed that redox cycling between the anode and cathode at the rGO/Au-IDA was established, which yields more sensitive detection than with a single electrode. As one application of the electrochemical immunoassay using the rGO/Au-IDA, we demonstrated the quantitative detection of cortisol, a stress marker, at levels found in human saliva.
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  • Yuki IWAHANA, Atsushi OHBUCHI, Yuya KOIKE, Masaru KITANO, Toshihiro NA ...
    Type: Original Papers
    2013 Volume 29 Issue 1 Pages 61-66
    Published: January 10, 2013
    Released: January 10, 2013
    JOURNALS FREE ACCESS
    Radioactive nuclides in the incinerator ashes of municipal solid wastes were determined by γ-ray spectrometry before and after the accident at the Fukushima nuclear power plant (March 11, 2011). Incinerator ash samples were collected in northern Kyushu, Japan, which is located approximately 1200 km west-southwest (WSW) of the Fukushima nuclear power plant, from April 2006 to March 2007 and from March 2011 to October 2011. 40K, 137Cs, 208Tl, 212Pb, 214Pb, 212Bi, 214Bi, and 228Ac were identified in the ashes before the accident (∼February 2011) and 134Cs was identified along with these eight nuclides in the ashes after the accident (March 2011∼). A sequential extraction procedure based on a modified Tessier method with added water extraction was used for 1st fly ash sampled in August 2011 because the highest activity concentrations of 134Cs and 137Cs were observed for this sample. The speciation of radioactive nuclides in the fly ash was achieved by γ-ray spectrometry and powder X-ray diffractometry for the extraction residues. Little variation was observed in the distribution of the chemical forms of 134Cs and 137Cs in 1st fly ash of municipal solid waste; one half of 134Cs existed as water soluble salts and the other half as carbonate compounds, whereas 75% of 137Cs existed as water soluble salts with the remainder as carbonates(10%) and sulfides (15%). These results show that 88% of the total radioactive Cs existed in water soluble and ion extractive forms and might be at risk for elution and diffusion with rain and wind.
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  • Takuya OKAZAKI, Wenjing WANG, Hideki KURAMITZ, Noriko HATA, Shigeru TA ...
    Type: Original Papers
    2013 Volume 29 Issue 1 Pages 67-72
    Published: January 10, 2013
    Released: January 10, 2013
    JOURNALS FREE ACCESS
    An improved molybdenum blue spectrophotometry using a soluble membrane filter and CaCO3-column was proposed for determining arsenic in drinking water supplied from ground water in the presence of phosphate. A 100 mL sample solution containing 0.5 – 10 μg arsenic was passed through a CaCO3-column to remove phosphate, arsenate (As(V)). Arsenite (As(III)) which was not retained on the column was oxidized to As(V). As(V) was converted into a heteropolymolybdenum blue anion. The blue anion was collected on a membrane filter as an ion-associate with n-dodecyltrimethylammonium ion by filtration. The filter was dissolved in 2 mL of 2-methoxyethanol. The absorbance of the solution was measured at 810 nm against a reagent blank. Total inorganic arsenic was determined by reducing As(V) to As(III) before the column treatment. The RSDs for 10 μg L−1 of As(III) and As(V) were 2.9%. Phosphate 0.2 mg L−1 (as P) and iron 0.1 mg L−1 did not interfere with the determination of 10 μg L−1 arsenic. The proposed method was successfully applied to ground waters.
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  • Tomoyuki YAMAMOTO, Yusuke TSUNEMINE, Fumio HAYAKAWA, Tamer H. A. HASAN ...
    Type: Original Papers
    2013 Volume 29 Issue 1 Pages 73-77
    Published: January 10, 2013
    Released: January 10, 2013
    JOURNALS FREE ACCESS
    A flow chemiluminescence (CL) method combined with a liquid–liquid extraction technique is proposed for the indirect determination of antimony in aqueous samples using rhodamine B (RB). In the liquid–liquid extraction process, the antimony(V) chloro-complex anion, [SbCl6], was extracted from an aqueous acidic solution into toluene via ion-pair formation with the protonated RBH+ ion. Upon mixing the extract with a reversed micellar reagent solution of cetyltrimethylammonium chloride (CTAC) in 1-hexanol–cyclohexane/water (0.60 mol dm−3 H2SO4) containing cerium(IV), uptake of the ion-pair by CTAC reversed micelles occurred easily, followed by an oxidation reaction of RB with Ce(IV) in the CL process. The CL signal produced was then measured. Using a flow injection system, the detection limits (DL) of 0.25 μmol dm−3 Sb(III) and 0.20 μmol dm−3 Sb(V), and linear calibration graphs with dynamic ranges from the respective DLs to 16 μmol dm−3 for Sb(III) and Sb(V) were obtained under optimized experimental conditions. The proposed method was successfully applied to a mixture of Sb(III) and Sb(V), where total antimony, Sb(III) + Sb(V), was measured using ceric sulfate as an oxidant to oxidize Sb(III) to Sb(V) prior to extraction, Sb(V) was determined directly without the use of an oxidant, and Sb(III) was calculated by difference.
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  • Yohei YAMADA, Tetsuya HAYASHI, Haruhiko SAKURABA, Tomoki YABUTANI, Tos ...
    Type: Original Papers
    2013 Volume 29 Issue 1 Pages 79-83
    Published: January 10, 2013
    Released: January 10, 2013
    JOURNALS FREE ACCESS
    We fabricated a thermostable quinoprotein aldose sugar dehydrogenase (tPQQ-ASD derived from a hyperthermophilic archaeon Pyrobaculum aerophilum) immobilized electrode. The electrode was prepared by immobilizing agarose gel mixed with the enzyme and carbon nanofiber (CNF) on a carbon paste (CP) electrode containing p-benzoquinone (BQ) as an electron mediator. The electrocatalytic response was clearly observed by the addition of D-glucose at the electrode. The electrode properties such as pH, temperature dependency and substrate selectivity basically followed the enzyme properties. The current response against D-glucose increased with measurement temperatures up to 70°C, and response perturbation caused by dissolved oxygen level was not observed at the electrode. As for the results of long-term stability evaluation, the current response was stable for 30 days when the electrode was stored in HEPES buffer solution (pH 7.0) at 4°C.
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  • Tomohiro UCHIMURA, Yuki HIRONAKA, Misako MORI
    Type: Original Papers
    2013 Volume 29 Issue 1 Pages 85-88
    Published: January 10, 2013
    Released: January 10, 2013
    JOURNALS FREE ACCESS
    Multiphoton ionization/time-of-flight mass spectrometry (MPI/TOFMS) was modified for the rapid analysis of gasoline-contaminated soil. This technique uses a nanosecond laser emitting at 266 nm, and has the potential to produce the mass spectrum for gasoline 30 min after sampling. The rapidity and robustness of the method can be applied to the screening of gasoline-contaminated soils while minimizing the risk of contamination when gas chromatograph (GC) is used. GC/MPI/TOFMS was used for a simultaneous determination of aromatic compounds of gasoline in a soil sample, and this was achieved without interference. A peak for toluene can be observed from 0.02 ng of gasoline, and ten peaks of aromatic hydrocarbons, which are sensitive to measurement by a laser, can be observed from 0.65 ng of gasoline. The MPI/TOFMS had good sensitivity and selectivity, and was therefore useful for the rapid analysis of gasoline-contaminated soils.
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  • Mika TADA, Yoshiko ONO, Masaaki NAKAI, Masami HARADA, Hiroshi SHIBATA, ...
    Type: Original Papers
    2013 Volume 29 Issue 1 Pages 89-94
    Published: January 10, 2013
    Released: January 10, 2013
    JOURNALS FREE ACCESS
    Antioxidative effects of sesamin (a mixture of sesamin and episesamin) were evaluated in the liver, kidney and inferior vena cava of living rats using a radiofrequency ESR method. TEMPOL, 4-hydroxy-2,2,6,6-tetramethylpiperidine 1-oxyl, was used as an in vivo redox probe, the half-life of which is believed to be correlated with the antioxidant status. The oral administration of sesamin (250 mg/kg rat weight) 3 h before ESR measurements shortened the half-life of TEMPOL in the liver by 10 – 15% as compared with the controls, but did not affect the other organs. This effect was maintained for at least 3 h after the administration, and then disappeared at 24 h, corresponding to the results of our preliminary pharmacokinetic studies. Changes in the reducing ability were observed only in the hepatic sites of the sesamin-treated rats. These findings suggest that sesamin exhibits effective antioxidant activity in the liver via modulation of the intracellular redox status related to TEMPOL reduction.
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  • Kotaro MORITA, Kenichi SHIBATA, Hirohisa NAGATANI, Naoki HIRAYAMA, His ...
    Type: Original Papers
    2013 Volume 29 Issue 1 Pages 95-99
    Published: January 10, 2013
    Released: January 10, 2013
    JOURNALS FREE ACCESS
    Covalent grafting of chromotropic acid (CA) moiety to a glassy carbon electrode was performed by electrochemical reduction of the corresponding diazonium cation generated in situ. Grafted electrodes were subjected to the electrochemical detection of multivalent cations using Fe(CN)63−/4− as an electrochemical probe molecule. In the absence of metal cations, redox reaction of the anionic probe was depressed by electrostatic repulsion between the probe and negatively charged CA moieties on the electrode surface. Binding of tetravalent cations such as Zr(IV) and Hf(IV) and trivalent cations such as Al(III) and lanthanide(III) to the CA moiety on the electrode surface resulted in an increase in the current intensity of the probe due to a decrease in electrostatic repulsion. Highly selective detection of the tetravalent cations was achieved in the micromolar concentration range at pH 1.0.
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  • Yukina TAKAHASHI, Natsumi MIYAHARA, Sunao YAMADA
    Type: Original Papers
    2013 Volume 29 Issue 1 Pages 101-105
    Published: January 10, 2013
    Released: January 10, 2013
    JOURNALS FREE ACCESS
    We succeeded in fabricating a localized surface plasmon resonance (LSPR) sensor comprising gold nanorods (AuNRs) that were immobilized in a thin film of titanium oxide. First, AuNRs were electrostatically immobilized onto a glass substrate; then, dip-coating of the thin titanium oxide film was carried out. These procedures were realized to prepare well-dispersed AuNRs onto a substrate with a uniform titanium oxide layer. The titanium-oxide-coated AuNRs could retain their rod-shape, even after annealing at 300°C for 1 h, since titanium oxide effectively prevented any heat-induced shape change of the AuNRs. The peak shifts of the plasmon bands of the immobilized AuNRs were observed with the change in the environmental refractive indices, even after titanium oxide coating. In addition, the as-prepared titanium oxide layer exhibited photocatalytic activity for methylene blue dye molecule under UV irradiation. This suggests that the titanium-oxide-coated AuNRs can conveniently be reusable even for unwanted contamination with organic compounds, due to their photocatalytic decomposition with UV light.
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  • Fumihiko KITAGAWA, Hiroshi SUDAKI, Kenji SUEYOSHI, Koji OTSUKA
    Type: Original Papers
    2013 Volume 29 Issue 1 Pages 107-112
    Published: January 10, 2013
    Released: January 10, 2013
    JOURNALS FREE ACCESS
    The preparation of cinchonidine (CCND) nanocrystals and their immobilization onto the inner surface of a fused silica capillary was investigated for use in the enantioseparation by capillary electrochromatography. The CCND nanocrystals were prepared by an emulsion method that utilizes crystal growth in an oil-in-water emulsion without a stabilizer. As a result, white-colored aqueous dispersions of organic nanoparticles were obtained. SEM images showed that the prepared CCND nanocrystals were from 300 to 700 nm in size. When the obtained dispersion was introduced into a poly(diallyldimethylammonium chloride) (PDDAC) coated capillary, the nanocrystals were strongly adsorbed onto the inner surface due to an electrostatic interaction between cationic PDDAC and the negatively charged organic nanocrystals. In CCND nanocrystals coated capillary, CEC enantioseparations of racemic amino acids were successfully achieved. The reproducibilities of the detection times were acceptable with a relative standard deviation of less than 7%, indicating that stable nanocrystal coating could be obtained by our proposed method.
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  • Masayori SUWA, Kayoko MIYAMOTO, Hitoshi WATARAI
    Type: Original Papers
    2013 Volume 29 Issue 1 Pages 113-119
    Published: January 10, 2013
    Released: January 10, 2013
    JOURNALS FREE ACCESS
    We constructed an apparatus to measure the wavelength dispersion of the Faraday rotation in the visible region, and determined the Verdet constants of diamagnetic organic liquids, including aliphatic compounds, benzene derivatives, and naphthalene derivatives. These three groups were easily distinguished by the magnitudes of their Verdet constants. Based on the theory developed by Serber, we determined the enhancing effect of π*←π transitions on the visible-light Faraday rotation angles observed for aromatic compounds. Furthermore, we propose a novel approach for simultaneously observing Faraday rotation dispersion and natural optical rotatory dispersion.
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  • Daisuke KOZAKI, Masanobu MORI, Nobutake NAKATANI, Kaori ARAI, Tomoe MA ...
    Type: Original Papers
    2013 Volume 29 Issue 1 Pages 121-126
    Published: January 10, 2013
    Released: January 10, 2013
    JOURNALS FREE ACCESS
    Herein, we describe indirect UV detection–ion-exclusion/cation-exchange chromatography (IEC/CEC) on a weakly acidic cation-exchange resin in the H+-form (TSKgel Super IC-A/C) using sulfosalicylic acid as the eluent. The goal of the study was to characterize the peaks detected by UV detector. The peak directions of analyte ions in UV at 315 nm were negative because the molar absorbance coefficients of analyte anions and cations were lower than that of the sulfosalicylic acid eluent. Good chromatographic resolution and high signal-to-noise ratios of analyte ions were obtained for the separations performed using 1.1 mM sulfosalicylic acid and 1.5 mM 18-crown-6 as the eluent. The relative standard deviations (RSDs) of the peak areas ranged from 0.6 to 4.9%. Lower detection limits of the analytes were achieved using indirect UV detection at 315 nm (0.23 – 0.98 μM) than those obtained with conductometric detection (CD) (0.61 – 2.1 μM) under the optimized elution conditions. The calibration curves were linear in the range from 0.01 to 1.0 mM except for Cl, which was from 0.02 to 2.0 mM. The present method was successfully applied to determine common inorganic ions in a pond water sample.
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  • Akira OHASHI, Natsumi KAWASHIMA, Kazuaki SATO, Haeng-Boo KIM
    Type: Original Papers
    2013 Volume 29 Issue 1 Pages 127-132
    Published: January 10, 2013
    Released: January 10, 2013
    JOURNALS FREE ACCESS
    The synergistic effect of five 8-quinolinol derivatives (HQs) on the extraction of gallium(III) with di(2-ethylhexyl)-phosphoric acid (D2EHPA or HA) from weak nitric acid into supercritical carbon dioxide (SC-CO2) was investigated. 8-Quinolinol (Hq), 5-ethoxymethyl-8-quinolinol (HO2q), 5-hexyloxymethyl-8-quinolinol (HO6q), 5-(2,2,2-trifluoroethoxymethyl)-8-quinolinol (HFO2q), and 5-chloro-8-quinolinol (5-Cl-Hq) were used as synergists. Synergism was observed for all of the HQs. The synergistic effect increased in the following order: Hq < HO2q < HFO2q < 5-Cl-Hq ≈ HO6q. The extent of synergism can be related to both the distribution constant and the acid dissociation constant of the HQ. The synergistic extraction equilibrium of gallium(III) with D2EHPA and 5-Cl-Hq into SC-CO2 was investigated; the results suggest that the composition of the extracted complex is as GaA2Q·HA. The synergistic extraction mechanism was the same for both SC-CO2 and n-heptane. The synergistic extraction equilibrium constants in both cases were calculated based on the experimental results.
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  • Kenji SUEYOSHI, Fumihiko KITAGAWA, Koji OTSUKA
    Type: Original Papers
    2013 Volume 29 Issue 1 Pages 133-138
    Published: January 10, 2013
    Released: January 10, 2013
    JOURNALS FREE ACCESS
    The effects of a low-conductivity (low-C) zone of an on-line sample preconcentration based on field-amplified sample stacking (FASS) under an acidic condition was investigated in microchip micellar electrokinetic chromatography (MCMEKC). By employing originally fabricated microchips with T- and cross-channel injectors on a single device, partial injection of the low-C zone and large-volume injection of a sample solution were demonstrated. As a typical result, the observed peak intensities of the fluorescent dyes were 1.5 – 2.0-fold enhanced by partial injection of the low-conductivity zone, as compared to those in FASS-MCMEKC without injecting the low-C zone; also, 30 – 40-fold enhancements of the detectability were achieved as compared to the conventional MCMEKC analyses. The resolutions of the hydrophobic analytes were also improved by introducing the low-C zone. The difference in the retention factors of model analytes in the high-C background and low-C zones was also estimated in order to clarify the effect of the low-C zone on the resolution and detectability in FASS-MCMEKC.
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Notes
  • Takaaki WAJIMA
    Type: Notes
    2013 Volume 29 Issue 1 Pages 139-141
    Published: January 10, 2013
    Released: January 10, 2013
    JOURNALS FREE ACCESS
    Ion exchange properties of five different Japanese natural zeolites in seawater were examined. Sodium ions could be reduced by all zeolites, although anions, Cl and SO42−, in seawater showed barely changes. Natural zeolite desalination treatment mainly depends on the ion exchange between Na+, K+ and Mg2+ in seawater and Ca2+ in natural zeolite. This study found that mordenite is superior to clinoptilolite for use in Na+ reduction. Mordenite with high cation exchange capacity containing Ca2+ resulted in the highest Na+ reduction from seawater.
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  • Yaeko SUZUKI, Fumikazu AKAMATSU, Rumiko NAKASHITA, Takashi KORENAGA
    Type: Notes
    2013 Volume 29 Issue 1 Pages 143-146
    Published: January 10, 2013
    Released: January 10, 2013
    JOURNALS FREE ACCESS
    We determined the δD values of the total fatty acids of Japanese rice to test the hypothesis that there is a wide variation in the hydrogen isotopic composition (δD) of the total fatty acids of Japanese rice sourced from different growth areas in Japan and to distinguish the minor differences among these growth areas. The δD values showed a wide variation ranging from –216‰ (Hokkaido) to –183‰ (Okinawa), indicating a good correlation with the corresponding variations for ambient water (r = 0.63) and mean temperature (r = 0.84). These results suggest that the δD values for the total fatty acids can be representative of the growth environments in Japan.
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  • Kojiro SHIMOJO, Ayaka NAKAI, Hiroyuki OKAMURA, Akira OHASHI, Hirochika ...
    Type: Notes
    2013 Volume 29 Issue 1 Pages 147-150
    Published: January 10, 2013
    Released: January 10, 2013
    JOURNALS FREE ACCESS
    Selective separation of lead ions (Pb2+) from aqueous solutions containing multiple divalent metal ions (Pb2+, Cu2+, Cd2+, Zn2+, Mn2+, Co2+, and Ni2+) was investigated using liquid–liquid extraction. N,N-Dioctyldiglycol amic acid (DODGAA) enabled quantitative extraction and efficient separation of Pb2+ from the metal ion mixture under mildly acidic conditions. Compared with conventional commercial extractants, DODGAA provided better extraction and excellent selectivity for Pb2+. The extraction of Pb2+ with DODGAA proceeded through a proton-exchange reaction and formed a 1:2 complex, Pb(DODGAA)2. The Pb2+ was readily stripped from the extracting phase under acidic conditions, and the organic solution with DODGAA could be recycled.
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  • Junichi HIRATA, Kazuya TAKAHASHI, Miho TANAKA
    Type: Notes
    2013 Volume 29 Issue 1 Pages 151-155
    Published: January 10, 2013
    Released: January 10, 2013
    JOURNALS FREE ACCESS
    A dilution method using MnO2 for the manganese nodule standard, JMn1, has been newly adopted to obtain accurate calibration lines. Moreover, an internal standard correction method was applied to correct changes in the sample introduction efficiency for the prime purpose of laser ablation–inductively coupled plasma–mass spectrometry (LA-ICP-MS) analysis. Using the dilution method and the correction method, good calibration lines were successfully obtained for 13 elements. The methods were also applied to the analysis of ferromanganese nodules. The results were in accordance with those obtained by ICP-MS, which requires chemical treatments of samples. The results are encouraging, and imply a high potential of LA-ICP-MS for the analysis of trace elements in ferromanganese nodules.
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  • Shingo SAITO, Takeshi MAEDA, Hiroyuki NAKAZUMI, Christa L. COLYER
    Type: Notes
    2013 Volume 29 Issue 1 Pages 157-159
    Published: January 10, 2013
    Released: January 10, 2013
    JOURNALS FREE ACCESS
    In this paper, the characterization and application of the “PectI” (polymer-enhanced capillary transient isotachophoresis) technique for the separation and detection of same genus, gram-positive bacteria, Bacillus globigii (Bg) and Bacillus subtilis, is demonstrated by employing a boronic acid-functionalized squarylium dye (SQ-BA) as an on-capillary labeling agent, including the quantitative performance and applicability to crude samples. The effect of borate in the separation buffer was also investigated, which revealed that borate strongly affects the separation behavior of bacteria.
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  • Shintaro KUBOTA, Osamu SHIRAI, Takao HIBI, Yuzuru TOZAWA, Kenji KANO
    Type: Notes
    2013 Volume 29 Issue 1 Pages 161-164
    Published: January 10, 2013
    Released: January 10, 2013
    JOURNALS FREE ACCESS
    Ion transports from one aqueous phase (W1) to another (W2) across bilayer lipid membranes (BLM) containing KAT1 potassium channel were investigated by recording current fluctuations. KAT1 channel is a voltage-gated K+ channel from Arabidopsis thaliana and has been suggested to have a key role in stomatal opening by osmoregulation in guard cells. Although KAT1 channel is a K+-specific transporter, the species of the counter anions significantly affected the level of the single channel current, suggesting that KAT1 also transported these anions. When various potassium salts were used as electrolytes, the single channel conductance decreased with an increase of the ionic radius of the coexisting anions except for F. This indicates the existence of selective permeation for anions, but the anion-selectivity is less noticeable than the cation-selectivity.
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  • Masaki TAKEUCHI, Yuki MIYAZAKI, Hiromichi TSUNODA, Hideji TANAKA
    Type: Notes
    2013 Volume 29 Issue 1 Pages 165-168
    Published: January 10, 2013
    Released: January 10, 2013
    JOURNALS FREE ACCESS
    During the summer of 2011 and winter of 2012, we continuously measured trace acid gas concentrations in Tokushima, Japan, using a parallel plate wet denuder coupled ion chromatograph. The average concentrations of hydrochloric acid (HCl), nitrous acid (HONO), nitric acid (HNO3), and sulfur dioxide (SO2) were, respectively, 0.54, 1.20, 1.17, and 3.22 μg m−3 in the summer, and 0.09, 1.06, 0.46, and 5.11 μg m−3 in the winter. In the summer, concentrations of all the acid gases increased after sunrise and showed a strong diurnal pattern with daytime maxima and nighttime minima, but the time at which concentration levels began to increase and the pace of increase differed among the acid gases. The concentration of HONO increased sharply immediately after sunrise, while concentrations of the other three gases began increasing about one and half hours later. SO2 showed the fastest rate of increase, followed by HNO3 and HCl. These differences were likely attributable to the formation processes of gaseous substances.
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