All issues
Volume 42, Issue 2
Displaying 1-13 of 13 articles from this issue
- |<
- <
- 1
- >
- >|
-
Mingyu DING, Yoshihito SUZUKI, Hitoshi KOIZUMI1993 Volume 42 Issue 2 Pages 49-54
Published: February 05, 1993
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSThe application of column switching method was studied in an attempt to separate organic acids and cations in beverages by ion chromatography with an eluent which can be used for anion and cation exchange columns. The columns and valves were assembled in such a way that the columns could be operated both in series and parallel. For precutting operation, a cation exchange column (Yokogawa ICS-C25, 4.6 mm i.d.×125 mm) and an anion exchange column (Yokogawa SAM3-075, 4.9 mm i.d.×75mm) were connected in series. Three and a half minutes after sample injection, when all anions in the sample has been transferred into the anion exchange column, flow of the eluent is changed by valve operation, so that the effluent from the cation exchange column directly enters the detector. When all cations are eluted from the cation exchange column, the valve is turned to the first position so that the effluent from the cation exchange column passes through the anion exchange column to serve as an eluent for separation of anions. The chromatograms for anions and cations can be recorded on a single chart with only one sample injection. Organic acids and five cations were separated at ambient temperature within 60 min when 1.5 mM oxalic acid at a flow rate of 0.75 ml/min was used as an eluent. The proposed method was applied to simultaneous determination of both organic acids and cations in wine, juice and coffee with good reproducibilities.View full abstractDownload PDF (731K) -
Kenji BANSHO, Hiroaki TAO, Takashi IMAGAWA, Akira MIYAZAKI1993 Volume 42 Issue 2 Pages 55-60
Published: February 05, 1993
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSFor the determination of trichloroethylene (TCE) in groundwater, a fiber-optic sensor, based on chemiluminescence detection with luminol, was prepared and tested. The sensor consisted of a glass fiber bundle (8mm diameter; 1m length) and a transducer. The transducer was composed of three components; a) a gas-permeable membrane to separate TCE from water, b) oxidizing agent which on reaction with TCE generates reaction gas needed for luminol chemiluminescence reaction, c) luminol solution. Mixture of sulfuric acid and sodium nitrate was selected as the oxidizing agent. The optimum pH of luminol solution was 8.5, and the optimum concentrations of luminol, H2O2, and sodium borate were 5×10-3 M, 2×10-2 M, and 5×10-2 M, respectively. The life time of the transducer was about 15 min, and the response time was shorter than 2 min. Calibration curve was linear at least from 0.05 to 0.6μg/ml and the relative standard deviation (n=6) for 0.5μg/ml was about 3%. Detection limit was 0.03μg/ml, and a 10m optical fiber sensor with photon-counting detection also showed the same sensitivity. Tetrachloroethylene was also measurable with the sensor although the sensitivity was about 1/4 times that for TCE.View full abstractDownload PDF (877K) -
Syuji OKUYAMA, Toshiyuki MITSUI, Toshiaki NOMURA, Yoshikazu FUJIMURA1993 Volume 42 Issue 2 Pages 61-65
Published: February 05, 1993
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSThe determination of each compound from overlapped peak in chromatogram was examined by principal component analysis. The method is as follows. The peak height on overlapped peak in chromatogram was measured for a distance of 2.5 mm each (chart speed; 240mm/min) with the maximum peak height as the central point. The measurement values were divided by the value of peak height on internal standard and used the calculation of principal component analysis. The quantitative analysis of peak heights was carried out by principal component analysis using these values. For example, methanol and ethyl acetate were analyzed from the overlapped peak in chromatogram by this method. The relative standard deviation (n=10) was 0.63% for methanol and 0.57 % for ethyl acetate when methanol and ethyl acetate mixture was used as the sample (50.00:50.00v/v%). The relative standard deviation (n=10) in the analysis of peak area from the same chromatogram was 3.92% for methanol and 0.88% for ethyl acetate.View full abstractDownload PDF (603K) -
Haruhiko TAJIMA, Toshiaki KABE, Atsushi ISHIHARA1993 Volume 42 Issue 2 Pages 67-75
Published: February 05, 1993
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSSulfur-containing polyaromatic hydrocarbons (PASH) in light oil were separated by high performance liquid chromatography (HPLC) with a silicagel column and ligand exchange chromatography with 10% PdCl2/silicagel column. Each component of PASH was analyzed by gas chromatography/atomic emission detection (GC/AED) and gaschromatography/mass spectrometry (GC/MS). Forty two kinds of alkylbenzothiophenes and twenty nine kinds of alkyldibenzothiophenes were identified and determined by GC/AED.View full abstractDownload PDF (1039K) -
Yasuhisa SHIBATA, Satoshi OZAWA, Hiroyuki MIYAGI1993 Volume 42 Issue 2 Pages 77-83
Published: February 05, 1993
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSEffect of plasticizers on selectivity of chloride ion-selective polymeric membrane electrodes (Cl- ISEs) based on quaternary ammonium salts was studied. Methyltrialkylammonium salts and a tetraalkylammonium salt with long alkyl chains having 1218 carbon atoms were used as sensing materials and ester, ether and alcohol compounds were used as plasticizers. All Cl-ISEs showed good Nernstean slope of -52-56 mV / dccade and wide lincarity range of 10-45×10-1 mol/l. But, itwas shown that selectivity was affected by the kind of plasticizers. When alcohol compounds were used, the selectivity factors to lipophilic anions were reduced. Especially, selectivity factor to SCN- was 23 orders of magnitude smaller than that of ether and ester compounds. This result was obtained by all CI-ISEs based on quaternary ammonium salts used in this study. From the comparison of alchohol compounds with same carbon atoms (1-undecyl alcohol and 5-phenyl-1-pentyl alcohol), it seemed that aliphatic alcohol was more effective than aromatic alcohol as a plasticizer in order to improve the selectivity of CI-ISEs.View full abstractDownload PDF (971K) -
Kenji KOBAYASHI1993 Volume 42 Issue 2 Pages 85-90
Published: February 05, 1993
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSZirconium fluoride and barium hydrogen fluoride were purified by diethyldithiocarbamate extraction and sublimation. Purity of the materials was estimated by NAA for transition elements and by charged particle activation analysis for oxygen. The impurity concentrations in purified zirconium fluoride were 2.6 ng/g iron, 0.018 ng/g for cobalt, 4.6 ng/g for nickel and 1.1 ng/g for copper. Trace amounts of iron and cobalt could be de-termined in the zirconium fluoride by irradiation for 265 h, followed by chemical separation. The concentrations of iron, cobalt, nickel and copper in the purified barium hydrogen fluoride were 17 ng/g, 0.044 ng/g, 1.41 ng/g and 0.2 ng/g, respectively. Trace amounts of nickel were determined using the 58Ni(n, p)58Co nuclear reaction. The analytical results for the transition elements in the prepared zirconium and barium hydrogen fluorides show that solvent extraction and sublimation are the best methods for the prepa-ration of high-purity raw materials for fluoride optical fiber.View full abstractDownload PDF (703K) -
Toshihiko IMATO, Takeshi YOSHIZUKA, Nobuhiko ISHIBASHI1993 Volume 42 Issue 2 Pages 91-98
Published: February 05, 1993
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSTetrafluoroborate (BF4-) ion-selective poly(vinyl chloride) (PVC) membrane electrodes based on hydrophobic quaternary ammonium ions are described. Dioctylphthalate (DOP), dioctyladipate, dioctylsebacate and ο-nitrophenyl octyl ether were examined as a plasticizer of the PVC membrane. Three quaternary ammonium ions, tridodecylhexa-decylammonium (TDHA), tetradodecylammonium ion and trioctylmethylammonium ion were evaluated as an anion exchanger for the electrode. The BF4- ion-selective PVC membrane electrode containing TDHA and DOP shows the best sensitivity to the BF4-ion; a linear response range from 10-1 to 3×10-6 M with the slope of 58mV/decade. Effects of pH and hydrofluoric acid on the potential of the BF4- ion-selective electrode were examined. Interference caused by HF2- ion present in solutions with a high concentration of HF was eliminated by adjusting the pH of the sample solution at about 6 adding a disodium hydrogenphosphate solution. The selectivity coefficients of the elec-trode for anions were determined by the mixed solution method. This electrode was ap-plied to monitoring the converting reaction of boron (a Na2B4O7 solution was chosen as the boron sample) into the BF4- ion with hydrofluoric acid. The apparent first-orderreaction constant of the above reaction was determined to be 0.039±0.006 (s-1) at 50°Cin the 1.0 M HF solution. A flow injection system with three-channels was constructed for the determination of boron utilizing the BF4- ion-selective electrode detector and a stream of the HF solution. The sample solution containing Na2B4O7 was injected into a carrier stream (water) and merged with a stream of the 1M HF solution and then the B(OH)4- ion was converted into the BF4- ion in a reaction coil (10m×0.5mm i.d., 80°C). Subsequently, the mixed stream was merged with a mixed solution of 0.5M Na2HPO4 and 0.5M Na2SO4 in order to neutralize the acidity and to keep the ionic strength of the solution constant. About 95% conversion was achieved within 2 min of residence time in the reaction coil at 80°C. The relationship between the peak height and the logarithmic concentration of B(OH)4- was almost linear with the slope of 56 mV/decade. The detection limit was 10 ppb-boron. A sampling rate of 20 samples/h was achieved with a relative standard deviation of 1.8 % (0.1 ppm-boron, n= 10). The effect of diverse ions on peak height signal for boron was examined and the interference with Al, P and Si was almost negligibly small but nitrate ion interfered.View full abstractDownload PDF (981K) -
Yoshiaki INAKI, Kenji MATSUKAWA, Hong WANG, Eiko MOCHIZUKI, Takehiko W ...1993 Volume 42 Issue 2 Pages 99-105
Published: February 05, 1993
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSDeoxyadenosine immobilized silica gels were prepared as the novel HPLC packing materials for the separation of nucleic acid fragments. Tetrathymidylic acid 5'-monophosphate {pd(T)4} was clearly separated from the other tetradeoxynucleotides by the specific interaction of complementary nucleic acid bases. The separation factor (α) of pd(T)4 increased with the decrease of columun temperature from 30°C to 5°C, because the specific bondings between the immobilized ligands and the complementary solutes are stabilized with the decrease of temperature. The presence of the hydrophilic spacer group between stationary phase and the nucleoside ligand caused higher separation efficiency for the complementary solute, compared with the stationary phase having no hydrophilic spacer groups. The "trityl-on" deoxyadenosine as the ligand was preferred to the unprotected one, which may be related to the conformation of the adenosine on silica gel.View full abstractDownload PDF (661K) -
Issei KASAHARA, Scott N. WILLIE, Ralph E. STURGEON, Shier S. BERMAN, S ...1993 Volume 42 Issue 2 Pages 107-110
Published: February 05, 1993
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSSeveral materials were tested for their usefulness as supports to immobilize 8-quinolinol through an azo bonding to prepare clean adsorbents for the preconcentration of trace metals in water. Satisfactory results were obtained with CAPCELL-NH2 (silicone-coated silica gel with alkyl amino groups), and with SEPABEADS (polyvinyl polymer with alkyl amino groups). The adsorbents synthesized from them are clean and can be used for the concentration of metals prior to determination by GFAAS or ICP-MS. Six metals (Cd, Cu, Fe, Ni, Pb, and Zn) in the standard seawater sample, NASS-3, were determined by GFAAS after enrichment with 8-quinolinol bonded SEPABEADS. The results were in good agreement with the certified concentrations.View full abstractDownload PDF (436K) -
Tsutomu YAMASHITA1993 Volume 42 Issue 2 Pages 111-113
Published: February 05, 1993
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSRare earth-iron magnetostriction alloy (0.1g) was decomposed with hydrochloric acid and hydrogen peroxide within a few minutes. The solution obtained was diluted to 100ml with water. To 10 ml of this diluted solution, an internal standard solution and hydrochloric acid were added and then diluted to 100 ml again with water. The amounts of Mn, Fe, Tb and Dy were measured by ICP-AES without any concomitant effect. Among the internal standard elements investigated (Sc, Y and La), La was most suitable. Recoveries of each element measured with a synthetic sample solution were over 99.7%. The relative standard deviations (n=5) were 0.04%0.35%.View full abstractDownload PDF (266K) -
Yoshifumi AKAMA, Hisashi SAITO, Akihiko HAYASHI, Kenji SATO, Sigeyuki ...1993 Volume 42 Issue 2 Pages 115-118
Published: February 05, 1993
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSA simple method was developed for the determination of trace keto-form PMBP admixtured in the commercial PMBP reagent; which is mainly yellow enol-form, by a differential thermal analysis technique. The enol-form PMBP (m.p. 92±1°C) is obtained by crystallization from hexane solution while the keto-form (m.p. 118±1°C) is obtainable by crystallization from ethanol solution. The white keto-form PMBP converts into enol-form upon melting. Calibration graph for keto-form, which was represented by the peak height ratio of keto- to enol-form in the DTA curve, is linear in the studied range (010wt% keto form). The relative standard deviation for five determinations was 4.3% at 0.7wt% level.View full abstractDownload PDF (372K) -
Jun-ichi KAWAHARA, Shigeru HATTORI1993 Volume 42 Issue 2 Pages T29-T36
Published: February 05, 1993
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSIn order to contribute to the fundamental methodology for the accuracy and the reliability of light scattering measurement, a typical light scattering photometer (FICA type) was evaluated in detail, from the viewpoint of the time stability of the instrumental constant, and was found to have some problems. On the basis of this investigation, it was shown that, by simple mechanical alterations and means, the accuracy and the operational convenience of the photometer can be increased significantly. It was also shown that the difference of cell constant between cells and cell directions is negligible in an immersion type light scattering photometer.View full abstractDownload PDF (1097K) -
Naoki OGURI, Akira ONISHI, Keiji NAKAHASHI, Shigeki UCHINO1993 Volume 42 Issue 2 Pages T37-T41
Published: February 05, 1993
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSHigh polar oligomer such as polyamide for the use of epoxy resin hardener, polyaniline and organic tin could be separated by the size exclusion chromatography with polystyrene gel column in chloroform containing 0.5% triethylamine as a mobile phase. No retardation for elution was observed for these materials, while it was observed without triethylamine in the mobile phase.View full abstractDownload PDF (539K)
- |<
- <
- 1
- >
- >|