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Takahiro KUMAMARU, Hidenori NOTAKE, Shiquan TAO, Yasuaki OKAMOTO
1997 Volume 13 Issue 6 Pages
885-889
Published: December 10, 1997
Released on J-STAGE: July 07, 2006
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A method based on the low-temperature electrothermal vaporization of an 8-quinolinolato complex from a tungsten boat cuvette is proposed for introducing a trace amount of aluminum present in a digested steel-making alloy or opal glass sample into an inductively coupled plasma for atomic emission spectrometric detection. The operating conditions were optimized and the effect of foreign ions was investigated. Zirconium(IV) was found to reduce the interferences from other foreign ions. The detection limit was found to be 0.12ng of aluminum and the precision in relative standard deviation for 2.0ng of aluminum was determined to be 6.1% (
n=6). The aluminum contents in some standard samples determined by the proposed method were in good agreement with the certified values.
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Xiang-Yu ZHANG, Keiichi SATOH, Atsushi SATOH, Kiyoshi SAWADA, Toshio S ...
1997 Volume 13 Issue 6 Pages
891-895
Published: December 10, 1997
Released on J-STAGE: July 07, 2006
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Simultaneous preconcentration extraction by trioctylmethylammonium chloride (TOMA•Cl) for the determination of trace amounts of twelve elements (Bi(III), Cd(II), Co(II), Cu(II), Fe(II), Hg(II), Mo(VI), Pb(II), Sb(III), Sn(II), V(V), Zn(II)) in natural water samples is described. A water sample containing 0.3mol dm
-3 HCl, 0.1mol dm
-3 KI, 0.1mol dm
-3 KSCN, and 0.01mol dm
-3 ascorbic acid was shaken with 2%(w/v) TOMA•Cl in xylene with a volume ratio (
Vaq/
Vorg) of 100. After preconcentration extraction, the organic phase was directly introduced into inductively coupled plasma atomic emission spectrometry. Twelve elements could be determined at the μg dm
-3 or ng dm
-3 level. Some natural water samples as well as standard reference material were analyzed by the proposed method. The results were highly satisfactory.
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Hiromichi YAMADA, Tetsuyoshi NAITO, Kazuto MIWA, Noriyuki TACHI, Hirok ...
1997 Volume 13 Issue 6 Pages
897-902
Published: December 10, 1997
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The partition constants of a number of carboxylic acids were determined for the partition systems using 1-octanol and benzene as a solvent, and the dimerization constants of carboxylic acids in the benzene phase were also determined. A linear relationship between the partition constants (log
KD, HA) of carboxylic acids and the molar volume of the respective carboxylic acids was found. A new good relationship on the partition equilibrium of carboxylic acids was found between the partition systems using 1-octanol and benzene, that is, a good linear relationship exists between the values of (log
K2, HA+2log
KD, HA) for benzene/water system and the values of log
KD, HA for 1-octanol/water system, irrespective of the kinds of carboxylic acids.
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Akinobu NASU, Susumu YAMAUCHI, Tatsuya SEKINE
1997 Volume 13 Issue 6 Pages
903-911
Published: December 10, 1997
Released on J-STAGE: July 07, 2006
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The solvent extraction of copper(II) in 1mol dm
-3 Na(SCN, NO
3), in which the thiocyanate concentration was 0.01 to 1mol dm
-3, with tetrabutylammonium ions (tba
+) into chloroform and with trioctylphosphine oxide (TOPO) into hexane was studied. Also, the solvent extraction of copper(I), which was formed by reducing copper(II) by ascorbic acid in these aqueous solutions, was studied. By a statistical analysis of the extraction data, it was concluded that copper(I) was extracted as tba
+Cu
I(SCN)
2- and Cu
ISCN(TOPO)
3, and copper(II) was extracted as (tba
+)
2Cu
II(SCN)
42- and Cu
II(SCN)
2(TOPO)
3. Although copper(I) was extracted with both extractants better than copper(II) in the lower thiocyanate concentration range, copper(II) was extracted better in the higher thiocyanate concentration range. This was concluded to be due to better extraction of the extractable species of copper(I) than those of copper(II); however, copper(I) formed unextractable complexes much more than did copper(II) in the higher thiocyanate concentration range in the aqueous phase.
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Yoshio MORIYA, Nobuaki OGAWA, Mikio SUGAI, Yozo OHSHIMA
1997 Volume 13 Issue 6 Pages
913-919
Published: December 10, 1997
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The extraction behavior of copper(II) with three carboxylic acids having a bulky substituent at the α-position was investigated in order to clarify the steric effect on the dimerization of copper(II) carboxylate extracted in benzene. Pivalate and 2-ethylbutyrate were found to be extracted only as a dimeric species Cu
2L
4(HL)
2through the slope analyses, taking into account the formation constant of (1:1) copper carboxylate complex in the aqueous phase. A new computing method based on fixing the species to the composition, Cu
2L
4(HL)
2, was proposed to estimate both the dimerization constant of carboxylic acid (
K2, HL) and the extraction constant of the dimeric copper species (
Kex(22)) for the case of carboxylic acid of higher carbon number in nonpolar solvents, and the extracted diphenylacetate was also found to be only a dimer as is usual. Consequently, under our experimental conditions, there was no evidence for the coextraction of monomeric copper(II) species caused by the steric hindrance as reported in other papers. Moreover, a linear relationship between log
Kex(22) and log
Ka was maintained by adding the three bulky substituent carboxylic acids.
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Hideyuki ITABASHI, Yoshikatsu TAKAZAWA, Norihiro NIIBE, Hiroshi KAWAMO ...
1997 Volume 13 Issue 6 Pages
921-924
Published: December 10, 1997
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The back-extraction rate of bis(dithizonato)cadmium(II) was measured, and the possibility of the mutual separation of cadmium(II) from zinc(II) with dithizone by back-extraction was considered. It was found that the back-extraction rate of zinc(II) was much lower than that of Cadmium(II), which could be almost back-extracted within 40s of shaking at pH 1.8, though under these conditions zinc(II) was scarcely back-extracted at all. Based on this, the kinetic separation of cadmium(II) from zinc(II) using a back-extraction procedure could be devised.
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Hirofumi TANI, Akira MATSUDA, Tamio KAMIDATE, Hiroto WATANABE
1997 Volume 13 Issue 6 Pages
925-929
Published: December 10, 1997
Released on J-STAGE: July 07, 2006
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Triblock copolymer surfactants, Pluronic L61 (L61) and Pluronic 25R2 (25R2), consisting of poly(ethylene oxide) (PEO) and poly(propylene oxide) (PPO) were utilized for the extraction of proteins. The extraction was based on phase separation into surfactant-depleted and -condensed phases (an aqueous phase and a surfactant-rich phase) upon warming aqueous solutions of L61 and 25R2. Hydrophilic cytochrome c was not extracted into the surfactant-rich phase in either Pluronics. However, hydrophobic cytochrome
b5 was extracted with L61, while not with 25R2. The difference in the extractability of cytochrome
b5 and cytochrome
c is probably due to the structural difference in L61 and 25R2.
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Yasushi ISHIHAMA, Yoshiya ODA, Naoki ASAKAWA, Masahiro IWAKURA
1997 Volume 13 Issue 6 Pages
931-938
Published: December 10, 1997
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Based on the difference between the electrophoretic mobility of the native protein and that of the unfolded one, the thermally-induced unfolding transition of proteins was analyzed by capillary electrophoresis (CE) using an in-column incubation method. In this method, the required amount of sample could be reduced to 100ng because the unfolding process occurred not in the sample vial, but in the separation capillary after the sample injection. The thermodynamic parameters of the unfolding transition process were obtained by analyzing the dependence of the electrophoretic mobilities on the temperature inside the capillary controlled by the thermostated water. The temperature inside the capillary was measured by an easy and rapid method on the basis of the dependence of the electrical current on the applied voltage. The electrophoretic mobility was converted to a temperature-independent parameter using the average of the electrical current through the analysis. In this work, the unfolding processes of several proteins were investigated. Although the apparent transition temperatures by CE were generally consistent with those obtained by far-UV CD using a two-state transition model, these two methods had different detection selectivity for the change in the protein structures. The CE method would offer additional information for the unfolding processes of proteins.
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Xiao-jing LIU, Yuan-zong LI, Yun-xiang CI
1997 Volume 13 Issue 6 Pages
939-944
Published: December 10, 1997
Released on J-STAGE: July 07, 2006
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The interaction of the La
3+-morin complex with DNA has been examined using fluorescence and absorption spectroscopic as well as viscosity measurement methods. The fluorescence intensity of La
3+-morin complex could be highly enhanced by DNA. In the presence of DNA the absorption wavelength or fluorescence excitation wavelength showed a red shift of 43-45nm, while the emission wavelength remained unchanged, consistent with groove binding of fluorescent dye with DNA. In contrast to intercalators, the complex showed an enhanced stacking effect, based on a viscometer measurement, on base pairs of DNA. The presence of both NaCl and phosphate showed a strong quenching effect on the fluorescence of the ternary system. This is also in favor of groove binding. Thus, groove binding rather than intercalation of the complex to DNA was suggested. Binding of the complex into a DNA narrow minor groove imposed constrains on free motion of the complex. Therefore, the non-radioactive deactivation of the excited state of the complex was inhibited and fluorescence enhancement was observed. The enhancement effect of DNA on the fluorescence of La
3+- morin complex was used for a quantitative and selective determination of double-stranded DNA. The detction limit was 20ng/ml.
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Mitsuhiro WADA, Naotaka KURODA, Shuzo AKIYAMA, Kenichiro NAKASHIMA
1997 Volume 13 Issue 6 Pages
945-950
Published: December 10, 1997
Released on J-STAGE: July 07, 2006
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A sensitive and rapid FIA using an immobilized enzyme column reactor was developed for the determination of D-amino acids in human plasma. This method is based on a specific enzymic reaction with
D-amino acid oxidase and a sensitive peroxyoxalate chemiluminescence (PO-CL) detection with bis(2, 4, 6-trichlorophenyl)oxalate and 2, 4, 6, 8- tetrathiomorpholinopyrimido[5, 4-
d]pyrimidine as CL reagents. Eleven kinds of D-amino acids could be independently detected quantitatively (
r=0.983-1.000). The detection limits of each D-amino acid ranged from 0.4 to 30pmol/10μl injection at a signal-to-noise ratio of 3. The average concentration level of D-amino acids in human plasma was found to be 14.6±4.7 (in the range of 5.0-24.3,
n=18)nmol/ml plasma. The correlation between the results obtained by the proposed FIA-PO-CL method and the colorimetric method was satisfactory (r=0.900). Moreover, this method is advantageous, since the net volume of the plasma sample needed was 2μl for each run; also, 5 samples could be analyzed within 10min.
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Russell B. POE, Yuzuru HAYASHI, Rieko MATSUDA
1997 Volume 13 Issue 6 Pages
951-962
Published: December 10, 1997
Released on J-STAGE: July 07, 2006
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With the theoretically predicted relative standard deviation (RSD) of measurements as a criterion, the ultra-violet detection wavelengths are optimized in a capillary electrophoresis system equipped with a diode-array, when analyte signals are baseline-separated in the time-direction and the measurements are the integration results in the time and wavelength directions. Some cold drugs and additives are taken as examples. The auto-correlation of an instrumental baseline at a diode (time-correlation) and the cross-correlation of measurements between different diodes (wavelength- correlation) are both taken into account for a better prediction of RSD. A simple method for estimating the wavelength- correlation is presented with a theoretical proof. This paper also shows that the measurement precision is governed to a large extent by the zero level setting of the time integration which accumulates the instrumental output relative to the zero level. The optimum (minimum RSD) is selected from among the wavelengths (190-300nm) and possible zero level settings. The validity of the RSD prediction is statistically verified.
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Yukio YOKOYAMA, Tomoo AMAKI, Sohei HORIKOSHI, Hisakuni SATO
1997 Volume 13 Issue 6 Pages
963-967
Published: December 10, 1997
Released on J-STAGE: July 07, 2006
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An optimum combination of reversed-phase column type and eluent composition was selected for the practical separation of amino acids by gradient elution ion-pair chromatography. A butyl-silica (C4) column with a concentration gradient elution between 5mM SDS-10mM HClO4 solution and acetonitrile provided the best resolution for amino acids. The C4 column was most adequate for reducing the chromatographic cycle time including the column regeneration. The use of 5mM SDS as ion-pairing agent in relatively low concentration is economical and practical for replicate and routine analyses. The developed HPLC system is applicable to the analysis of organic cations at low cost.
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Kyung Lae RHO, Sang Hyun HAN, Hakhyun NAM, Geun Sig CHA, Kyoung II JOU ...
1997 Volume 13 Issue 6 Pages
969-974
Published: December 10, 1997
Released on J-STAGE: July 07, 2006
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In order to investigate the performance of different types of silicone rubber (SR) materials as matrices for ion-selective membrane electrodes, various cation-selective membranes are formulated from each of four different room temperature vulcanizing (RTV) SRs with addition of plasticizer. Four different neutral carrier-type cation ionophores (K
+, Ca
2+, and two Na
2+) were included in this study. These SR-based ion-selective membranes were compared with the corresponding PVC-based membranes in both conventional electrode body and coated wire-type electrode formats. All of the one-component RTV SRs except for the oxime-evolving type, were shown to exhibit similar potentiometric response characteristics for a given ionophore system. It was also shown, however, that their performance is greatly dependent on the type of the neutral carrier incorporated.
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Toshiaki HATTORI, Masanao KATO
1997 Volume 13 Issue 6 Pages
975-979
Published: December 10, 1997
Released on J-STAGE: July 07, 2006
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The potential response to ethanol was examined by a flow-through ion sensor using a plasticized poly(vinyl chloride) membrane doped with several amphiphilic ions. When an amphiphilic cation was used, a negative potential slope to ethanol was observed. When an amphiphilic anion was used, however, a positive potential slope was observed. These potential slopes were affected by the hydrophobicity and the shape of the amphiphilic ions. The results of these potential slopes supported the mechanism previously proposed for the potential response to anionic polyelectrolyte, that is, the change of phase-transfer force of the amphiphilic ion from the membrane to the sample solution dominated the potential response. The present ISE method was applied to the determination of ethanol in several liquors. The determination values agreed well with those obtained by a gas chromatographic method.
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Kei TODA, Shuichi HASHIGUCHI, Seiki OGUNI, Isao SANEMASA
1997 Volume 13 Issue 6 Pages
981-986
Published: December 10, 1997
Released on J-STAGE: July 07, 2006
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The detection of nitrogen oxides contained in air was investigated using their redox cycles. NO and NO
2 gases can be detected by means of interdigitated array (IDA) electrodes made of Au that are fabricated on a gas-permeable membrane. The IDA electrodes were applied to a gas detection system for the first time. Although the membrane is soft and flexible, and has pores, the electrodes can be formed successfully on it by photolithography devised in our laboratory. Between the electrodes, redox cycles are produced, and, hence, the gas sensitivities increase. The reactions in this redox cycles are not simple, and it was confirmed that nitrate produced on the generator electrode reacts with NO gas on the collector in the NO detection system. The increase in sensitivity based on the generation of the redox cycle in amperometric detection appears to be improved by decreasing the distance between the electrodes.
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Yoshiaki KURAUCHI, Masaaki NAGASE, Naoyoshi EGASHIRA, Kazuya OHGA
1997 Volume 13 Issue 6 Pages
987-990
Published: December 10, 1997
Released on J-STAGE: July 07, 2006
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A total-internal-reflection-type fiber-optic sensor having a crosslinked Chitosan/poly(vinyl alcohol) blended membrane as the cladding responded reversibly to organic solvents such as alcohols, acetone, acetonitrile, dioxane and chloroform in water. The response was explained on the basis of an increase in the refractive index of the cladding membrane by organic solvents. Larger responses were observed to solvents having lower dielectric constants. When the cladding membrane was coated with a thin Teflon protective membrane, the response time depended on the vapor pressure of the solvents, and was 30s for acetone with a high vapor pressure. The response to chloroform was ca. ten-times larger than that to ethanol, and a linear relationship was obtained in the concentration range of 5 to 50mM.
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Masayuki ITAGAKI, Masaki HOSONO, Kunihiro WATANABE
1997 Volume 13 Issue 6 Pages
991-996
Published: December 10, 1997
Released on J-STAGE: July 07, 2006
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The transfer function,
H(ω), for fluorescence emission of pyrene in ethanol has been calculated from the excitation ray and fluorescence time profiles by the fast Fourier transformation (FFT) process. The
H(ω) describes a clear semicircle on the Nyquist plane at low pyrene concentration. On the other hand, at high pyrene concentration the real part of
H(ω) takes a negative value and the locus deviates from a semicircle at high frequency region. The theoretical expressions of the
H(ω) have been derived on the basis of the fluorescence emission model containing the formation of excimer:
H(
ω)=2.3
αεlc
P{
kf1(
jω+
K2)+
kf2kecP}/{(
jω+
K1)(
jω+
K2)-
K3}
K1=
kq1+
kf1+
kecP,
K2=
kb+
kf2+
kq2,
K3=
kbkecP where α is correction factor, ε is the molar extinction coefficient, l is the cell length and
cP is the concentration of pyrene.
Ke and
kb†are the formation rate constant and its reverse rate constant, respectively.
kf
1 and
kq1 represent rate constants of fluorescence emission and quenching of excited pyrene, respectively.
kf2 and
kq2 represent rate constants of fluorescence emission and quenching of excimer, respectively. The results simulated by this equation were in good agreement with experimental results. In the course of simulation, kinetic parameters for the pyrene fluorescence were obtained.
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Songyan ZHENG, Yohichi GOHSHI
1997 Volume 13 Issue 6 Pages
997-1001
Published: December 10, 1997
Released on J-STAGE: July 07, 2006
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Numerical simulations of X-ray absorption near edge structure (XANES) of Au L
3-edge have been done by total electron yield (TEY) at grazing incidence angles of 12mrad and 4mrad. A 4mrad incidence angle is a total reflection condition and a 12mrad incidence angle is above the total reflection state. The results of calculations show that the signal to background ratio (S/B) of XANES at incidence angle of 4mrad is greater than that at incidence angle of 12mrad. Experimental results are in agreement with numerical simulations.
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Songyan ZHENG, Yohichi GOHSHI
1997 Volume 13 Issue 6 Pages
1003-1005
Published: December 10, 1997
Released on J-STAGE: July 07, 2006
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The purpose of this paper is to extend the use of conversion-electron-yield (CEY) detection in in-situ zeolite analysis. The experimental results demonstrate that CEY detection for chemical state observation of 0.1wt% Ni adsorbed on zeolite is attainable.
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Murad I. H. HELALEH, Nafisur RAHMAN, Eyad S. M. ABU-NAMEH
1997 Volume 13 Issue 6 Pages
1007-1010
Published: December 10, 1997
Released on J-STAGE: July 07, 2006
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An accurate and simple quantitative method for determining levodopa and methyldopa is proposed. Cerium(IV) has been successively used to react with drugs in 2M H
2SO
4†at 80°C. The absorbance of colored products was measured at 510 and 550nm for levodopa and methyldopa, respectively. The method has been extended to the determination of these drugs in dosage forms. The results have been statistically compared with those obtained by the reference method.
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Masami FUKUSHIMA, Shunitz TANAKA, Ken NAKAYASU, Keiko SASAKI, Hiroshi ...
1997 Volume 13 Issue 6 Pages
1011-1015
Published: 1997
Released on J-STAGE: July 27, 2007
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Shoji KOZUKA, Yuji YAMADA, Miyuki TAKENAKA, Masaru HAYASHI, Hideki MAT ...
1997 Volume 13 Issue 6 Pages
1017-1019
Published: December 10, 1997
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Isao KOJIMA, Miwa KATSUZAKI
1997 Volume 13 Issue 6 Pages
1021-1023
Published: December 10, 1997
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Achmad SUBAGIO, Naofumi MORITA
1997 Volume 13 Issue 6 Pages
1025-1028
Published: December 10, 1997
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J. RODR, J. RODRÍGUEZ, G. GASTAÑEDA
1997 Volume 13 Issue 6 Pages
1029-1032
Published: December 10, 1997
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Susumu KAWAKUBO, Takashi NETSU, Masaaki IWATSUKI
1997 Volume 13 Issue 6 Pages
1033-1035
Published: December 10, 1997
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Akio MASUI
1997 Volume 13 Issue 6 Pages
1037-1038
Published: December 10, 1997
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Yong CHE, Manabu TSUSHIMA, Takeyoshi OKAJIMA, Koichi TOKUDA, Takeo OHS ...
1997 Volume 13 Issue 6 Pages
1039-1042
Published: December 10, 1997
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Takaya TAKEI, Chikara AMANO, Yuko NISHIMOTO, Yoshinori SUGITANI
1997 Volume 13 Issue 6 Pages
1043-1045
Published: December 10, 1997
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Yusaku SUENAGA, Masahiko MAEKAWA, Takayoshi KURODA-SOWA, Megumu MUNAKA ...
1997 Volume 13 Issue 6 Pages
1047-1049
Published: December 10, 1997
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Orhan ATAKOL, Filiz ERCAN, Dincer ULKÜ, Nazife YILMAZ
1997 Volume 13 Issue 6 Pages
1051-1052
Published: December 10, 1997
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Goro YASUDA, Hisashi MORIKAWA, Hiroshi KIMOTO
1997 Volume 13 Issue 6 Pages
1053-1054
Published: December 10, 1997
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M. Nawaz TAHIR, Dincer ÜLKÜ, Mustafa TASTEKIN, Orhan ATAKOL
1997 Volume 13 Issue 6 Pages
1055-1056
Published: December 10, 1997
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Kentaro YAMAGUCHI, Zenzo TAMURA, Masako MAEDA
1997 Volume 13 Issue 6 Pages
1057-1058
Published: December 10, 1997
Released on J-STAGE: July 07, 2006
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