Analytical Sciences
Online ISSN : 1348-2246
Print ISSN : 0910-6340
ISSN-L : 0910-6340
Volume 22 , Issue 12
Showing 1-26 articles out of 26 articles from the selected issue
Call for Papers
Original Papers
  • Satoshi YAMAGUCHI, Tomohiro UCHIMURA, Totaro IMASAKA
    2006 Volume 22 Issue 12 Pages 1483-1487
    Published: 2006
    Released: December 12, 2006
    JOURNALS FREE ACCESS
    Gas chromatography/multiphoton ionization/time-of-flight mass spectrometry (GC/MPI/TOF-MS) using a femtosecond laser source has been developed and applied to analysis of an authentic sample containing five polychlorinated dibenzofurans (PCDFs). The ionization efficiency was substantially improved for compounds such as tetrachlorinated dibenzofuran (tetraCDF) and pentachlorinated dibenzofuran (pentaCDF) using a femtosecond laser, instead of a nanosecond laser currently used for this purpose. The relatively poor efficiencies in nanosecond ionization can be attributed to the short lifetimes of the singlet excited states that are efficiently relaxed to triplet levels by intersystem crossing. The detection limits for pentaCDF isomers, i.e., 1,2,3,8,9-pentaCDF (non-toxic) and 1,2,3,7,8-pentaCDF (toxic), were determined to be ca. 100 pg, when the femtosecond laser was employed. The present method has the potential for use in the detection and determination of toxic PCDD/Fs in exhaust gas from an incinerator, because of the high inherent selectivity of GC and the high sensitivity of MPI/TOF-MS.
    Download PDF (83K)
  • Takayuki ASAMI, Hisanori IMURA
    2006 Volume 22 Issue 12 Pages 1489-1493
    Published: 2006
    Released: December 12, 2006
    JOURNALS FREE ACCESS
    A highly sensitive and accurate determination method for trace quantities of enantiomers of glufosinate (D,L-GLUF), a phosphorus-containing amino acid-type herbicide, has been studied. The present method is based on the change in the mole ratio of the enantiomeric isomers after spiking of a known amount of an isomer (L-GLUF). The chiral separation and detection were made by γ-cyclodextrin modified capillary zone electrophoresis (γ-CD-CZE) with fluorescence detection. Solid-phase extraction of D,L-GLUF with titania was investigated as the pre-separation method to eliminate coexisting materials such as inorganic salts and organic compounds in river water. A separated D,L-GLUF was labeled with dansyl chloride and subjected to the on-capillary concentration using large-volume sample stacking (LVSS) before γ-CD-CZE. The detection limit of the present method was as low as 2.0 × 10-9 M. The present method was successfully applied to a model sample containing 2.0 × 10-7 M D,L-GLUF in river water. It was confirmed that trace quantities of D-and L-GLUF in environmental samples can be accurately determined without any calibration curves and comparison standards.
    Download PDF (91K)
  • Tomohisa YAMASHITA, Shuji KODAMA, Mikiya OHTO, Eriko NAKAYAMA, Sumiyo ...
    2006 Volume 22 Issue 12 Pages 1495-1500
    Published: 2006
    Released: December 12, 2006
    JOURNALS FREE ACCESS
    The permeation fluxes of phenol, benzene sulfonate (BS) and benzene disulfonate (BDS) through a porous anodic alumina membrane with the perpendicularly oriented silica-surfactant nanochannel assembly membrane (NAM) were measured in water-ethanol mixture media. The permeation flux depended on solute charges and on solvent composition. As the ethanol ratio increased, the fluxes of BS and BDS increased and the flux of phenol decreased. The results of extraction/elution experiments also depended on the solute charges and the solvent composition. Chromatographic experiments in n-hexane showed that dipole and hydrophobic interactions affect the retention of solutes. Permeation of the solute across the NAM in water-ethanol mixture is likely to be determined by various factors such as dipole interaction, hydrophobic interaction, solvation, and anion-exchange efficiencies.
    Download PDF (95K)
  • Akira YAMAGUCHI, Takashi YODA, Shintaro SUZUKI, Kotaro MORITA, Norio T ...
    2006 Volume 22 Issue 12 Pages 1501-1507
    Published: 2006
    Released: December 12, 2006
    JOURNALS FREE ACCESS
    The apparent diffusion coefficients of tris(2,2′-bipyridyl)ruthenium ([Ru(bpy3)]2+) are estimated in silica-nanochannels which are assembled inside columnar alumina pores in an anodic alumina membrane, and are modified with alkylsilanes such as trimethylchlorosilane (C1), butyldimethylchlorosilane (C4), and dodecyldimethylchlorosilane (C12). The estimation is performed by observing the lag-time, which is defined as the time required for [Ru(bpy)3]2+ to diffuse through alkylsilane-modified silica-nanochannels in the alumina membrane. When ethanol is used as a solvent, the apparent diffusion coefficients of [Ru(bpy)3]2+ are estimated as 2.1 × 10-10 and 3.2 × 10-10 cm2 s-1 in the C1- and C4-modified silica-nanochannels, respectively. These values are about 104 times smaller than that obtained in bulk ethanol. Based on the experimental results on the solvent dependency of the lag-time, the hydrogen-bonding interaction between ethanol molecules is considered to be stronger in the C1- and C4-modified silica-nanochannels than in bulk ethanol, and the hydrogen-bonding interaction plays a critical role for the slow diffusivity in those nanochannels. In contrast, the apparent diffusion coefficient in the C12-modified silica-nanochannel is at least two orders of magnitude larger than those in the C1- and C4-modified silica-nanochannels. This relatively fast diffusion is most likely explained by the presence of a long alkyl chain of C12, which reduces a hindrance effect that is originates in the hydrogen-bonding interaction.
    Download PDF (198K)
  • Kazuhiko TAKEDA, Shinya KATOH, Nobutake NAKATANI, Hiroshi SAKUGAWA
    2006 Volume 22 Issue 12 Pages 1509-1514
    Published: 2006
    Released: December 12, 2006
    JOURNALS FREE ACCESS
    The aim of this research was to develop a simple procedure for a highly sensitive determination of low-molecular-weight (LMW) carbonyl compounds in drinking water and natural water. We employed a preconcentration HPLC system with 2,4-dinitrophenylhydrazine (DNPH) for the determination of LMW carbonyl compounds. A C-18 reverse-phase preconcentration column was used instead of a sample loop at the sample injection valve. A 0.1 - 5.0 mL portion of the derivatized sample solution was injected with a gas-tight syringe, and a 15% acetonitrile aqueous solution was pushed through the preconcentration column to remove the unreacted excess DNPH, which caused serious interference in the determination of formaldehyde. The detection limits were 1 - 3 nM with a relative standard deviation of 2 - 5% for 20 nM standard solutions (n = 5). The calibration curves were essentially unaffected by coexisting sea salts. Applications to commercial mineral water, tap water, river water, pond water and seawater are presented.
    Download PDF (91K)
  • Shiwang LIU, Li-Wei ZHANG, Xin-Xiang ZHANG
    2006 Volume 22 Issue 12 Pages 1515-1518
    Published: 2006
    Released: December 12, 2006
    JOURNALS FREE ACCESS
    The interactions between eight fluoroquinolone antibiotics (ciprofloxacin, enoxacin, fleroxacin, levofloxacin, lomefloxacin, norfloxacin, ofloxacin, pefloxacin) and bovine serum albumin (BSA) were studied by affinity capillary electrophoresis (ACE). The binding constants were estimated by the change of migration times of the analytes through the change of concentration of BSA in the buffer solution. The yield binding constants were between 3.19 × 104 and 1.21 × 105 M-1. These were related with the structures of fluoroquinolones, and agreed with the results obtained by other techniques. The obtained binding constants may help us in gaining some insights on possible drug/protein interactions and in early evaluation of the drugs' pharmacokinetic profiles during drug discovery.
    Download PDF (77K)
  • Shiro MATSUOKA, Yu NAKATSU, Kô TAKEHARA, Sulistyo SAPUTRO, Kazuh ...
    2006 Volume 22 Issue 12 Pages 1519-1524
    Published: 2006
    Released: December 12, 2006
    JOURNALS FREE ACCESS
    A novel on-line oxidation method of ultra-trace Cr(III) dissolved in natural water has been developed using a flow electrolysis cell. This method was successfully applied to the determination of the total Cr concentration by flow injection-solid phase spectrophotometry using diphenylcarbazide as a coloring agent. With the applied potential of 1.35 V (vs. Ag/AgCl) and the flow rate of 0.80 cm3 min-1, Cr(III) was quantitatively oxidized to Cr(VI) at room temperature. The total Cr concentration of sub-µg dm-3 in 3 - 4 samples could be determined within 1 h using an aqueous sample volume of 7.1 cm3. The analytical values of the total Cr concentration in natural water were in good agreement with those obtained by ICP-MS. The detection limit of the proposed method was 0.014 µg dm-3 (3σ, n = 7). This method could be applied to the specific determination of Cr(III) and Cr(VI) in river water samples.
    Download PDF (116K)
  • Sang Hyun KWON, Yoshio OKAMOTO, Chiyo YAMAMOTO, Wonjo CHEONG, Myeonghe ...
    2006 Volume 22 Issue 12 Pages 1525-1529
    Published: 2006
    Released: December 12, 2006
    JOURNALS FREE ACCESS
    Porous zirconia particles are very robust material and have received considerable attention as a stationary phase support for HPLC. We prepared cellulose dimethylphenylcarbamate-bonded carbon-clad zirconia (CDMPCCZ) as a chiral stationary phase (CSP) for separation of enantiomers of a set of 14 racemic compounds in normal phase (NP) and reversed-phase (RP) liquid chromatography. Retention and enantioselectivity on CDMPCCZ were compared to those on CDMPC-coated zirconia (CDMPCZ) to see how the change in immobilization method of the chiral selector affects the retention and chiral selectivity. In NPLC, retention was longer and the number of resolved racemates was smaller on CDMPCCZ than on CDMPCZ. However, chiral selectivity factors for some resolved racemates were better on CDMPCCZ than on CDMPCZ. The longer retention on CDMPCCZ is likely due to strong, non-chiral discriminating interactions with the carbon layer on CDMPCZ. In RPLC only two racemates were resolved on CDMPCCZ, but retention times were shorter than, and resolutions were comparable to, those in NPLC, indicating a potential for improving chromatographic performance of the CDMPCCZ column in RPLC with optimized column preparation and separation conditions.
    Download PDF (62K)
  • Satomi ONOUE, Baosheng LIU, Yoshitaka NEMOTO, Mariko HIROSE, Takehiko ...
    2006 Volume 22 Issue 12 Pages 1531-1535
    Published: 2006
    Released: December 12, 2006
    JOURNALS FREE ACCESS
    Thymopentin (TP5) is a synthetic pentapeptide fragment, which corresponds to position 32 - 36 of thymic polypeptide thymopoietin. Thymopoietin and TP5 display a variety of biological functions, including phenotypic differentiation of T cells and the regulation of immune systems. Previous chemical modification experiments suggested that there was an absolute requirement for N-terminal amino acids to maintain the biological activity of TP5. On the basis of this structure-activity relationship, we designed and synthesized the C-terminally 5-carboxyfluorescein-coupled TP5 (TP5-FAM) as a fluorescent probe for thymopoietin receptor. TP5-FAM could bind to the membrane of human lymphoid cell lines, MOLT-4 cells, in which the thymopoietin receptor is expressed. The binding is specific and saturable (Kd = 33 µM). TP5 and human splenopentin are nearly equipotent inhibitors of TP5-FAM binding to the thymopoietin receptor, but porcine secretin did not show any significant inhibition of TP5-FAM binding to MOLT-4 cells. Thus, TP5-FAM is suggested to be a potent and biologically active ligand that would be useful for studying the binding and functional characteristics of the human thymopoietin receptor.
    Download PDF (135K)
  • Yuichi MICHIKAWA, Kentaro FUJIMOTO, Kenji KINOSHITA, Seiko KAWAI, Keis ...
    2006 Volume 22 Issue 12 Pages 1537-1545
    Published: 2006
    Released: December 12, 2006
    JOURNALS FREE ACCESS
    In the present work, a convenient microarray SNP typing system has been developed using a plastic base that covalently immobilizes amino-modified oligonucleotides. Reliable SNP allele discrimination was achieved by using allelic specificity-enhanced enzymatic extension of immobilized oligonucleotide primer, with a locked nucleic acid (LNA) modification at the SNP-discriminating 3′-end nucleotide. Incorporation of multiple biotin-dUTP molecules during primer extension, followed by binding of alkaline phosphatase-conjugated streptavidin, allowed optical detection of the genotyping results through precipitation of colored alkaline phosphatase substrates onto the surface of the plastic base. Notably, rapid primer extension was demonstrated without a preliminary annealing step of double-stranded template DNA, allowing overall processes to be performed within a couple of hours. Simultaneous evaluation of three SNPs in the genes TGFB1, SOD2 and APEX1, previously investigated for association with radiation sensitivity, in 25 individuals has shown perfect assignment with data obtained by another established technique (MassARRAY system).
    Download PDF (579K)
  • Chun-Lian HE, Feng-Lian REN, Xiao-Bing ZHANG, Yan-Yan DONG, Yan ZHAO
    2006 Volume 22 Issue 12 Pages 1547-1551
    Published: 2006
    Released: December 12, 2006
    JOURNALS FREE ACCESS
    In this research, bis(2,2′-bipyridine)(4-methyl-2,2′-bipyridine-4′-carboxylic acid)ruthenium(II)·2PF6- complex (1), was first used as a fluorescent chemosensor to recognize Cu(II) in EtOH/H2O (1:1, v/v) solution. The response of the sensor is based on the fluorescence quenching of complex 1 by binding with Cu(II). The analytical performance characteristics of the proposed Cu(II)-sensitive chemosensor were investigated. The sensor can be applied to the quantification of Cu(II) with a linear range covering from 5.0 × 10-8 to 1.0 × 10-4 M and a detection limit of 4.2 × 10-8 M. The experiment results show that the response behavior of 1 to Cu(II) is pH independent in medium condition (pH 4.0 - 8.0), and show excellent selectivity for Cu(II) over other transition metal cations.
    Download PDF (90K)
  • Tatjana ANDJELKOVIC, Jelica PEROVIC, Milovan PURENOVIC, Srdjan BLAGOJE ...
    2006 Volume 22 Issue 12 Pages 1553-1558
    Published: 2006
    Released: December 12, 2006
    JOURNALS FREE ACCESS
    Isolated soil humic acid (HA) and commercial Aldrich HA were derivatized by esterification with methanol-thionyl and acetylation with acetic anhidride, in order to obtain derivatives with selectively blocked carboxyl and phenol groups, respectively. Results obtained by FT-IR spectroscopy and potentiometry show that the methanol-thionyl procedure is a selective, specific and efficient route for blocking carboxyl groups. The good correlation between results obtained by direct potentiometry after HA esterification and by classical calcium-acetate and baryta exchange methods suggests that esterification followed by direct acid-base potentiometric titration can be used as a method for the estimation of carboxyl and phenol group contents. Phenol groups can not be specifically identified by the acetylation method, due to the low selectivity of the acetylation method. The average values of apparent and intrinsic pK of underivatized and derivatized HAs confirm decrease in ionizable groups content due to derivatization and their values are related to the different chemical structures of the acids.
    Download PDF (93K)
  • Ken'ichi NARITA, Kiyoshi MATSUMOTO, Manabu IGAWA
    2006 Volume 22 Issue 12 Pages 1559-1563
    Published: 2006
    Released: December 12, 2006
    JOURNALS FREE ACCESS
    The determination of SO42- concentration in individual rain droplets can be achieved using a gelatin film containing 5 mM barium chloride and 5 mM barium nitrate. SO42- in droplets reacts with barium chloride in the film to form the characteristic Liesegang rings. The areal ratio of the ring to the droplet print (ARRD) on the film is a good indicator for determining the SO42- concentrations in an individual droplet. Interference by NO3- in determining SO42- concentration can be avoided by adding barium nitrate to the gelatin. Measurements of SO42- in rainwater samples by this method agreed well with those from ion chromatography. The individual analysis of rain droplets by this method indicated that the concentrations of SO42- were largely different with a 5-order magnitude, even among individual rain droplets collected simultaneously, and were higher in smaller rain droplets.
    Download PDF (113K)
  • Huafeng FU, Jiyu GUAN, James J. BAO
    2006 Volume 22 Issue 12 Pages 1565-1569
    Published: 2006
    Released: December 12, 2006
    JOURNALS FREE ACCESS
    A new direct method has been developed to determine protein-drug binding based on hollow fiber membrane solvent microextraction. Hollow-fiber membrane solvent microextraction coupled with high-performance chromatography with UV detection was employed to evaluate the binding characteristics of drugs to bovine serum albumin (BSA) and blood serum. It was found that the BSA and matrix in the blood serum did not interfere with the measurement. The method is simple and fast. It lacks the drawbacks of some conventional analytical techniques, such as taking much long time and requiring large volume sample consumption.
    Download PDF (72K)
  • Kô TAKEHARA, Yuki MORINAGA, Shinya NAKASHIMA, Shiro MATSUOKA, Hi ...
    2006 Volume 22 Issue 12 Pages 1571-1575
    Published: 2006
    Released: December 12, 2006
    JOURNALS FREE ACCESS
    With the fluorescence probe of 8-anilino-1-naphthalenesulfonate (ANS), the binding modes of terminally substituted alkane analogues (CnX; X = COOH, OH, CHO, NH3, CONH2) to bovine serum albumin (BSA) were investigated using a competitive binding technique. The Scatchard plot of the fluorometric titration of BSA with ANS showed that the maximum binding number of ANS, nmax, was 3.81, with the binding constant, Kbnd, of 1.42 × 106 mol-1 dm3. The binding modes of CnX to BSA were analyzed based on the fluorometric titration of the ANS and BSA mixture with CnX. CnCOOH completely displaced the ANS bound to BSA, whereas CnOH and CnCHO displaced only about 40% of the ANS bound to BSA. In contrast, CnNH2 and CnCONH2 displaced very little bound ANS. By comparing these results, we classified the binding modes of CnX to BSA into three types. Two of them are detectable with the ANS fluorescence and the remaining one is not detectable with the fluorescence.
    Download PDF (98K)
Notes
Announcements
feedback
Top