Analytical Sciences
Online ISSN : 1348-2246
Print ISSN : 0910-6340
ISSN-L : 0910-6340
Volume 10 , Issue 1
Showing 1-47 articles out of 47 articles from the selected issue
  • Manabu NAKATANI, Akimasa SHIBUKAWA, Terumichi NAKAGAWA
    1994 Volume 10 Issue 1 Pages 1-4
    Published: February 10, 1994
    Released: July 04, 2006
    JOURNALS FREE ACCESS
    Sodium dodecyl sulfate (SDS)-linear polyacrylamide-bonded capillary electrophoresis has been developed for the separation and molecular weight determination of proteins. Vinyl groups were introduced to silanol groups on the inner wall of fused silica capillaries by a Grignard reaction, followed by reaction of the vinyl group with acrylamide, resulted in a sieving medium of linear polyacrylamide attached through hydrolytically stable Si-C linkages. The durability of the developed capillary were improved as compared with the SDS-linear polyacrylamide-filled capillary using a conventional fused silica capillary. An excellent linear relationship existed between the mobility and the logarithm of the molecular weight of proteins (r2>0.998). The relative standard deviation of migration times was below 1.0% (n=10).
    Download PDF (243K)
  • Hitoshi NOHTA, Hee-Kyoung JEON, Masaaki KAI, Yosuke OHKURA
    1994 Volume 10 Issue 1 Pages 5-9
    Published: February 10, 1994
    Released: July 04, 2006
    JOURNALS FREE ACCESS
    This paper describes a method for the determination of indoleamine (5-hydroxytryptamine) and its precursor (5-hydroxytryptophan) and metabolites (5-hydroxyindoleacetic acid and 5-hydroxytryptophol) simultaneously with catecholamines (norepinephrine, epinephrine and dopamine) and their precursor (L-3, 4-dihydroxyphenylalanine) and metabolites (normetanephrine, metanephrine, 3-methoxytyramine, 3, 4-dihydroxymandelic acid, 3, 4- dihydroxyphenylacetic acid, vanillylmandelic acid, homovanillic acid, 3, 4-dihydroxyphenylethylene glycol and 4-hydroxy-3-methoxyphenylethylene glycol). The method uses reversed-phase liquid chromatography with postcolumn fluorescence derivatization involving a periodate oxidation. This is followed by reaction with meso-1, 2-diphenylethylenediamine in the presence of hexacyanoferrate(III). The detection limits (S/N=3) varied from 13 to 570fmol on column, depending on the compounds. The method can be applied to the determination of these compounds in four discrete brain regions (striatum, cerebral cortex, hypothalamus and hippocampus) from rats treated with saline, pargyline (a monoamine oxidase inhibitor) and probenecid (an acid transport inhibitor).
    Download PDF (328K)
  • Akira TERAKITA, Akimasa SHIBUKAWA, Chikako NAKAO, Terumichi NAKAGAWA
    1994 Volume 10 Issue 1 Pages 11-15
    Published: February 10, 1994
    Released: July 04, 2006
    JOURNALS FREE ACCESS
    A micro high-performance frontal analysis (MHPFA) using a small-bore internal-surface reversed-phase silica column (10cm×1.0mm or 1.5mm id.) was developed for the simultaneous determination of the total and unbound carbamazepine (CBZ) concentrations in a human serum albumin (HSA) solution. When a 100-μl or 200-μl portion of a 4-12μg/ml CBZ solution containing 593μM HSA was directly injected into the column, CBZ gave a trapezoidal peak
    with the plateau being separated from the HSA peak. The CBZ concentration, calculated from the plateau height, agreed well with the unbound drug concentration determined by the conventional ultrafiltration-HPLC method, and the CBZ concentration calculated from the peak area coincided with the total concentration. The reproducibility was satisfactory (RSD, <3.79%, n=5 or 6). The use of a glass-lined stainless-steel column and an injector-reswitching
    technique, which prevents the introduction of a diffused portion of the sample solution into the column, was necessary for a frontal analysis using these small-bore columns. The present MHPFA reduced the sample volume to as low as one-seventh of that required for HPFA using an internal-surface reversed-phase silica column of conventional size (15cm×4.6mm i.d.).
    Download PDF (358K)
  • Junichi KONDO, Nobuyuki SUZUKI, Toshi IMAOKA, Takao KAWASAKI, Akio NAK ...
    1994 Volume 10 Issue 1 Pages 17-23
    Published: February 10, 1994
    Released: July 04, 2006
    JOURNALS FREE ACCESS
    Three chiral derivatization reagents: 2-[4-(L-leucyl)aminophenyl]-6-methoxybenzoxazole, 2-[4-(D-phenylglycyl)amino-phenyl]-6-methoxybenzoxazole, and 2-[4-(L-phenylalanyl)aminophenyl]-6-methoxybenzoxazole, have been synthesized to permit separation of carboxylic acid enantiomers by high-performance liquid chromatography. Enantiomeric carboxylic acids were readily condensed with the chiral reagents in the presence of 2, 2′-dipyridyl disulfide and triphenylphosphine. The diastereometric amides formed were separated on a normal-phase column, and were sensitively detected fluorometrically at 375nm, with excitation at 330nm. The detection limit of L-PheBOX derivative of 2-phenylpropionic acid was 70fmol at a signal-to-noise ratio of 3.
    Download PDF (464K)
  • Takashi YARITA, Akira NOMURA, Yoshiyuki HORIMOTO
    1994 Volume 10 Issue 1 Pages 25-29
    Published: February 10, 1994
    Released: July 04, 2006
    JOURNALS FREE ACCESS
    A multidimensional supercritical fluid chromatography (SFC)/gas chromatography (GC) system was developed for the characterization of citrus essential oils. For on-line coupling of SFC with GC, the carbon dioxide mobile phase used in the SFC was split after a UV detector and then introduced into a GC injector. The elution order in the SFC on a silicagel column was based on the polarities of the solutes. First, citrus essential oils were separated into three fractions (hydrocarbons, aldehydes and esters, and alcohols) by SFC utilizing stepwise pressure programming. Then, each fraction was introduced into the GC and determined using a flame ionization detector for the quantification of three fractions as well as their components in the oils. The SFC/GC system was applied to the characterization of citrus essential oils. All of the citrus essential oils used in this study mainly consisted of hydrocarbons.
    Download PDF (291K)
  • Nobuo UEHARA, Toshifumi KURAHASHI, Yoshio SHIJO
    1994 Volume 10 Issue 1 Pages 31-34
    Published: February 10, 1994
    Released: July 04, 2006
    JOURNALS FREE ACCESS
    The chromatographic behavior of tris(2-methyl-8-quinolinolato)gallium and other tris(methyl-substituted 8-quinolinolato)galliums was studied with a methanol-water mixture (80:20 v/v) containing 5×10-4mol dm-3 of the corresponding methyl-substituted 8-quinolinol and 2×10-3mol dm-3 of a hexamethylenetetramine buffer (pH 6.0). The chromatographic behavior of tris(2-methyl-8-quinolinolato)gallium and tris(2, 5-dimethyl-8-quinolinolato)gallium changed when the column was varied. The other tris(methyl-substituted 8-quinolinolato)galliums did not change. Tris(2-methyl-8-quinolinolato)gallium and tris(2, 5-dimethyl-8-quinolinolato)gallium were dissociated by EDTA among all of the tris(methyl-substituted 8-quinolinolato)galliums studied. It was suggested that the chromatographic behavior of tris(2-methyl-8-quinolinolato)gallium was influenced by the chelate forming the interaction of the silanol group on the stationary phase.
    Download PDF (273K)
  • Takaho WATANABE, Chang Qing LIN, Yoshihiro YOSHIMURA, Katsumi UCHIYAMA ...
    1994 Volume 10 Issue 1 Pages 35-38
    Published: February 10, 1994
    Released: July 04, 2006
    JOURNALS FREE ACCESS
    We propose a simple colorimetric method for determining chlorine dioxide in water in the presence of hypochlorite and/or chlorite. This method is based on the coloration of an m-aminobenzyl alcohol (ABA). The reagent solution changes from colorless to red-violet in the presence of chlorine dioxide. Since the red-violet coloration is proportional to the concentration of chlorine dioxide, this concentration can be determined by comparing it to a color standard of chloranilic acid. When ABA and chlorine dioxide react for 10min at pH 2-7, the detection limit of the chlorine dioxide is 0.1ppm. The maximum absorption wavelength of the reaction product of ABA and chlorine dioxide is 532nm. This product was separated by column chromatography, and the structure (C7H5O3Cl) was then determined by ultraviolet (UV), infrared (IR), nuclear magnetic resonance (NMR), and mass (MS) analyses.
    Download PDF (232K)
  • Chikara AMANO, Hiroshi ISHIGAKI
    1994 Volume 10 Issue 1 Pages 39-42
    Published: February 10, 1994
    Released: July 04, 2006
    JOURNALS FREE ACCESS
    A regular series of silver-carbon mixed cluster ions: AgmC2n(m=3, 5, 7, 9; n=1, 2, 3) has been found by mass spectrometry. This regularity is not destroyed by the energetic collisions of the cluster ions with argon atoms. Remarkable differences are observed in the chemical species produced between the cluster ions containing odd numbers of silver atoms and those containing even numbers of silver atoms. Size-selected reactions of the cluster ions with argon clearly show the magic numbers effect, in addition to the even-odd difference. The mechanism of formation of silver-carbon mixed cluster ions is studied. The authors propose that the mixed cluster ions are produced on a silver surface through decomposition and dehydrogenation of hydrocarbon molecules contained in the background gas of the ionization chamber. This picture is consistent with observations from scanning tunneling microscopy.
    Download PDF (257K)
  • Mitsuru EBIHARA, Haruka MINOWA, Hiromichi NAKAHARA, Chushiro YONEZAWA
    1994 Volume 10 Issue 1 Pages 43-48
    Published: February 10, 1994
    Released: July 04, 2006
    JOURNALS FREE ACCESS
    Zirconium and hafnium contents were determined by radiochemical neutron activation analysis for some basaltic and granitic geological standard rock samples. Our values for Zr and Hf are consistent with the literature values for basaltic samples, but are systematically higher than the literature data, especially for Zr, for granitic samples, though their relative ratios were found to be in good agreement with meteoritic values. The present work suggests that the literature values of Zr and Hf are systematically low for some granitic rock standard samples.
    Download PDF (437K)
  • C. T. YAP, Younan HUA
    1994 Volume 10 Issue 1 Pages 49-52
    Published: February 10, 1994
    Released: July 04, 2006
    JOURNALS FREE ACCESS
    A new relation between ln(fluorescent intensity ratio of analyte to pure analyte/concentration of analyte) and ln(fluorescent energy) can be expressed as ln(Ii/(Iioci))=aln(E)+b, where a and b are constants. This relation depends on the pure-element intensity (Ioi). Although the simplest way to obtain pure-element intensities is to use thick pure-metal foils, there are, however, many elements whose pure-metal foils are not available. This paper proposes a new method for determining pure-element intensities, which we shall call the "Low-Concentration Method". Essentially, by measuring the intensities of known low concentrations of elements in a known matrix and calculating the appropriate alpha coefficients from tabulated mass-absorption coefficients, the pure-element intensities can be obtained. It was found that such values are in good agreement with those obtained using thick metal foils as well as with those using oxides.
    Download PDF (235K)
  • Kozo MOMOKI, Yoshiyuki FUKAZAWA
    1994 Volume 10 Issue 1 Pages 53-58
    Published: February 10, 1994
    Released: July 04, 2006
    JOURNALS FREE ACCESS
    Whether the bulbed capillary external referencing method developed with an electromagnet NMR instrument can be performed also with a superconducting magnet instrument by only changing gcy from 2π/3 to 0 is studied. As the result, the same bulbed capillary and procedures giving high precisions and accuracies are found to be applicable to either electromagnet or superconducting magnet instrument and to either 1H or even 13C spectra. Thus, the validity of the generalized bulbed capillary theories and the superiorities of the bulbed capillary method over previous referencing methods are made clear.
    Download PDF (438K)
  • Shiquan TAO, Soulin LIN, Takahiro KUMAMARU
    1994 Volume 10 Issue 1 Pages 59-63
    Published: February 10, 1994
    Released: July 04, 2006
    JOURNALS FREE ACCESS
    A system of continuous laser vaporization coupled with graphite-furnace atomic absorption spectrometry and its characteristics for the direct analysis of solid samples are described. A detailed investigation indicated that the system was free from the influence of sample inhomogeneity when the solid samples were pulverized to under a size of 200 mesh. In addition, the continuous laser mode showed less matrix interference on the atomic absorption signals than
    did the pulsed-laser mode. The procedures for sample preparation and direct analysis of a solid sample are presented. The system was applied to the determination of trace copper and lead in geological solid samples; the obtained results show good agreement with the certified values.
    Download PDF (358K)
  • Maria BALCERZAK, Stanislaw KUS
    1994 Volume 10 Issue 1 Pages 65-69
    Published: February 10, 1994
    Released: July 04, 2006
    JOURNALS FREE ACCESS
    Ruthenium and osmium can be determined in the same solution by second-order derivative spectrophotometry after a conversion into complexes with tin(II) chloride. In a mixed solution containing 5M (1M=1mol dm-3) HCl and 0.05M SnCl2 ruthenium is quantitatively converted, from various oxidation states and various forms, into the complex RuCl2(SnCl3)22- after heating for 45min. The value of the second-derivative for the anionic complex with SnCl3- ligands at 22250cm-1 (zero-crossing point of osmium) is a measure of ruthenium concentration. Osmium can be determined after heating the solution containing 2M HCl and 0.4M SnCl2 for 1.5h. At 25900cm-1 the value of second-derivative is dependent only on osmium concentration (zero-crossing point of ruthenium). Ruthenium, in the concentration range 2-35μg/ml (in the presence up to 450μgOs/ml), and osmium, in the concentration range 7.5-90μg/ml (in the presence up to 45μgRu/ml), can be determined with good precision and accuracy, without separation.
    Download PDF (315K)
  • Yoshiaki SASAKI, Shoji TAGASHIRA, Yoshiko MURAKAMI, Hiroaki NAKADA
    1994 Volume 10 Issue 1 Pages 71-75
    Published: February 10, 1994
    Released: July 04, 2006
    JOURNALS FREE ACCESS
    Chromium(VI) reacts with O, O′-dibutyl dithiophosphate ion to form tris(dibutyl dithiophosphato)chromium(III) and tetrabutyl thiophosphoryl disulfide in an acidic solution (pH 1.2-1.7). Both of the products are extracted into hexane and the absorbance at 278nm based on these products is utilized for the determination of chromium(VI). The chromium(III) complex corresponding to two-thirds of the initial chromium(VI) concentration and the disulfide corresponding to three-halves of the initial chromium(VI) concentration are extracted under the optimum conditions. The calibration graph obtained is linear over the range of 2×10-6-1×10-4mol/dm3 chromium(VI) concentration, and the apparent molar absorptivity (absorbance per initial chromium(VI) concentration in aqueous phase) is 1.69×104mol-1 dm3 cm-1. This method is subject to interference from CuII, FeII, CdII, PbII, HgII, PdII, SnIV, SbIII, SeIV, AuIII, nitrite, sulfite, thiosulfate and ascorbic acid. This method was applied to the determination of chromium in steel samples, and good results were obtained.
    Download PDF (299K)
  • Akio SAKURAGAWA, Satoshi NAKAYAMA, Tadao OKUTANI
    1994 Volume 10 Issue 1 Pages 77-81
    Published: February 10, 1994
    Released: July 04, 2006
    JOURNALS FREE ACCESS
    A rapid and simple flow-injection method using a reaction column packed with barium chromate powder is described for the determination of micro amounts of sulfate ion in surface- and sea-water samples. An aqueous solution containing 4.5mM sodium acetate and 4% ethanol was used as a carrier solution at a flow rate of 0.8ml/min. The absorbance of the chromate ion (which corresponds to the sulfate ion concentration) in the carrier solution from the reaction column was measured using a photometric detector at 370nm. Interference from some cations was eliminated by the use of a cation-exchange resin column installed in front of the reaction column; interference from some anions was reduced by using the carrier solution mentioned above. The concentration range from 0.5 to 5ppm of the sulfate ion in practical water samples can be determined by the proposed method with good reproducibility.
    Download PDF (288K)
  • Shigehiro KAGAYA, Shiro KOSUMI, Joichi UEDA
    1994 Volume 10 Issue 1 Pages 83-87
    Published: February 10, 1994
    Released: July 04, 2006
    JOURNALS FREE ACCESS
    An analytical method involving lead in water was studied using differential pulse polarography (DPP) after being concentrated by the rapid coprecipitation technique with indium hydroxide. Indium hydroxide coprecipitates quantitatively 1-1500μg of lead from up to 1000cm3 of sample solution at a pH of about 9. The presence of indium does not affect the polarogram of lead. Since the concentration of indium is also measurable by DPP, the rapid coprecipitation technique, which does not require a complete collection of the collector precipitate, becomes possible using a known amount of indium and measuring the concentrations of both lead and indium in the final sample solution by DPP. The calibration curve is linear over the 0.04-60μg cm-3 range of lead. Of the 39 diverse ions tested, tin(IV) and selenium(IV) interfered with the determination. The effect of tin(IV), however, could be eliminated by the addition of phosphoric acid. The proposed method is rapid and applicable to the determination of lead in water samples.
    Download PDF (299K)
  • Hanming WANG, Erkang WANG
    1994 Volume 10 Issue 1 Pages 89-93
    Published: February 10, 1994
    Released: July 04, 2006
    JOURNALS FREE ACCESS
    The transfer behavior of the heteropoly anion [H3PW11O39]4- and the isopoly anion [H2W12O39]4- across the water/nitrobenzene interface was investigated by cyclic voltammetry and chronopotentiometry with linear current scanning. The transfer processes were diffusion-controlled. The effect of pH on the transfer behavior and the formation of isopolytungstates and heteropolytungstates anions in the water phase was studied. Parameters related to interface, the transfer half-wave potential and the standard transfer Gibbs energy, were estimated and transfer mechanisms are discussed.
    Download PDF (234K)
  • Baizhao ZENG, Zhuang LIU, Xingyao ZHOU
    1994 Volume 10 Issue 1 Pages 95-99
    Published: February 10, 1994
    Released: July 04, 2006
    JOURNALS FREE ACCESS
    A rapid and sensitive polarographic method for the determination of bilirubin is described. In a solution containing 0.03M NaOH, 1.0×10-3M Na2SO3 and 2.0×10-4M EDTA, bilirubin can cause a polarographic wave at about -0.26V (vs. SCE) when potential sweeps from -0.65V to -0.1V. The peak current varies linearly with bilirubin concentration over a range of 8.0×10-8M to 6.0×10-6M as determined by derivative linear sweep polarography. A low detection limit of 5×10-8M is obtained. The method has been developed for the determination of bilirubin in serum and medicine. In this research, the characteristics of the polarographic wave have been investigated, and it has been confirmed to be an adsorptive wave. The electrochemical mechanism is discussed, the wave is ascribed to the oxidation of mercury.
    Download PDF (340K)
  • Shoji MOTOMIZU, Nahoko MORI, Masayoshi KUWABARA, Mitsuko OSHIMA
    1994 Volume 10 Issue 1 Pages 101-103
    Published: 1994
    Released: July 27, 2007
    JOURNALS FREE ACCESS
    Download PDF (166K)
  • Hitoshi WATARAI, Yoshito CHIDA
    1994 Volume 10 Issue 1 Pages 105-107
    Published: 1994
    Released: July 27, 2007
    JOURNALS FREE ACCESS
    The two methods gave successfully the interfacial absorption spectra. The capillary plate method seems superior to the other in the simplicity of device, the stability of the interface and the reproducibility. The detection limit in this method can be improved by the use of multiple plates. The fraction of interface in a liquid-liquid system can be evaluated in terms of the specific interfacial area, a. The specific interfacial area for the stir cell is determined by the diameter of droplets, d, through the equation of a=6/d, which yields 67cm-1 for the present system. On the other hand, the specific interfacial area for the capillary plate is determined solely by the thickness of the organic phase with the equation of a=2/1, which affords 20cm-1 for the present case.
    Though the value of a of the optical stir cell is larger than the other, the spectrum observed in the stir cell method is seriously interfered with by refraction at the toluene droplet surface.
    Further investigations on the interfacial reactions, including protonation and metal complex formation, are in progress in which the Teflon capillary plate method is being used.
    Download PDF (173K)
  • Shinichi MIYAIRI, Akiko KANAMARU, Kumiko NAKAJIMA, Toyoaki KATO, Junic ...
    1994 Volume 10 Issue 1 Pages 109-111
    Published: 1994
    Released: July 27, 2007
    JOURNALS FREE ACCESS
    Download PDF (145K)
  • Mizuo MAEDA, Masaharu MURATA, Kazuhiko TSUKAGOSHI, Makoto TAKAGI
    1994 Volume 10 Issue 1 Pages 113-115
    Published: 1994
    Released: July 27, 2007
    JOURNALS FREE ACCESS
    Download PDF (238K)
  • Yoshimune NONOMURA, Hitoshi HATANO, Kazuki FUKUDA, Hidenari INOUE
    1994 Volume 10 Issue 1 Pages 117-119
    Published: February 10, 1994
    Released: July 04, 2006
    JOURNALS FREE ACCESS
    Download PDF (156K)
  • Yutaka SAITO, Masaki MIFUNE, Kimiya OKAZAKI
    1994 Volume 10 Issue 1 Pages 121-123
    Published: February 10, 1994
    Released: July 04, 2006
    JOURNALS FREE ACCESS
    Download PDF (196K)
  • Masataka HIRAIDE, Mohammad-Hussein SOROURADIN, Hiroshi KAWAGUCHI
    1994 Volume 10 Issue 1 Pages 125-127
    Published: February 10, 1994
    Released: July 04, 2006
    JOURNALS FREE ACCESS
    Download PDF (174K)
  • Yoshihiro KUDO, Tokiko KOBAYASHI, Tatsuya EZAKI, Ibrahim H. REFAAT, Ya ...
    1994 Volume 10 Issue 1 Pages 129-131
    Published: February 10, 1994
    Released: July 04, 2006
    JOURNALS FREE ACCESS
    Download PDF (206K)
  • Haruki SHIRAISHI, Reiji TAKAHASHI
    1994 Volume 10 Issue 1 Pages 133-135
    Published: February 10, 1994
    Released: July 04, 2006
    JOURNALS FREE ACCESS
    Download PDF (140K)
  • Kazumasa HONDA, Midori GOTO, Isao KOJIMA, Isao SHIBUYA
    1994 Volume 10 Issue 1 Pages 137-138
    Published: February 10, 1994
    Released: July 04, 2006
    JOURNALS FREE ACCESS
    Download PDF (79K)
  • Nobuya NAGASHIMA, Takahiro SATO, Eiji NAKANISHI, Kunisuke IZAWA, Yoich ...
    1994 Volume 10 Issue 1 Pages 139-141
    Published: February 10, 1994
    Released: July 04, 2006
    JOURNALS FREE ACCESS
    Download PDF (138K)
  • Makoto TAKAGI, Yosuke OHKURA
    1994 Volume 10 Issue 1 Pages 145
    Published: February 10, 1994
    Released: July 04, 2006
    JOURNALS FREE ACCESS
    Download PDF (70K)
  • Erkang Wang
    1994 Volume 10 Issue 1 Pages 147
    Published: February 10, 1994
    Released: July 04, 2006
    JOURNALS FREE ACCESS
    Download PDF (71K)
  • Ru-Qin YU, Yu-Long XIE
    1994 Volume 10 Issue 1 Pages 149-153
    Published: February 10, 1994
    Released: July 04, 2006
    JOURNALS FREE ACCESS
    In this paper, robust statistical procedures in chemometrics have been reviewed. Two robust multivariate calibration methods: robust Kalman filter and robust principal component analysis via projection pursuit, are proposed.
    Download PDF (351K)
  • Erkang WANG
    1994 Volume 10 Issue 1 Pages 155-156
    Published: February 10, 1994
    Released: July 04, 2006
    JOURNALS FREE ACCESS
    An ECSTM apparatus with an ideal tip using a homemade SSX-1A STM instrument has been constructed. STM and ECSTM tips were made by electrochemical etching and insulating with paraffin, silicon rubber or epoxy resin under an optical microscope. In situ imaging of highly oriented pyrolytic graphite (HOPG) shows that the leakage current passing through the tip has been effectively eliminated. By this technique we have studied the growth and mechanism of polypyrrole films on HOPG. Using the STM technique we have also studied a metalloporphyrin compound, FAD and tungstosilicic acid modified on HOPG.
    Download PDF (151K)
  • Ki-jung PAENG, Insook RHEE PAENG, James R. KINCAID
    1994 Volume 10 Issue 1 Pages 157-159
    Published: February 10, 1994
    Released: July 04, 2006
    JOURNALS FREE ACCESS
    A new fast mixing device has been developed. Our attention has been paid to improving the apparatus design in order to decrease the mixing dead time and to enhance the mixing efficiency. We modified and, mainly, simplified the system proposed by Clegg. The new device comprises two concentric tubes and a platinum spherical ball with a single piece of Teflon used as a support housing. Mixing is thus performed by the induced turbulent flow which can be generated by forcing a liquid stream to flow through channels between a Pt ball and a glass wall. This device offers many advantages relative to conventional mixing devices. The 99% mixing time for the device has been found to be 30-80μs, which is at least a factor of 10 faster than the older devices. This technique can be applied using any type of fast reaction, solvent or laser. The stability of the stream and the excellent reproducibility allow measurements of the rate constants of very fast reactions.
    Download PDF (185K)
  • Liping ZHANG, Kikuo TERADA
    1994 Volume 10 Issue 1 Pages 161-165
    Published: February 10, 1994
    Released: July 04, 2006
    JOURNALS FREE ACCESS
    A simple and rapid method has been established for spectrophotometric determination of cobalt(II) in water after preconcentration by sorbing the nitroso R (sodium-1-nitroso-2-hydroxynaphthalene-3, 6-disulfonate) complex of cobalt(II) on poly(chlorotrifluoroethylene) resin. The cobalt-nitroso R complex was quantitatively retained on the resin as an ion associate complex with tetrabutylammonium cation in the range of pH 5.5 to 8.5. The retention capacity was
    41.6μg (0.71μmol) Co g-1 resin at a maximum flow rate of 30ml min-1. Cobalt retained on the resin column was completely extracted with 5ml of methanol which was submitted to spectrophotometric measurement at 550nm after 1ml of 1.0mol dm-3 nitric acid was added. The proposed method was applied to a river water sample.
    Download PDF (313K)
  • Yuko HASEGAWA, Fumie WATANABE, Miho TAKAHASHI
    1994 Volume 10 Issue 1 Pages 167-170
    Published: February 10, 1994
    Released: July 04, 2006
    JOURNALS FREE ACCESS
    The extraction behavior of lanthanoids(III) from 1M Na(SCN, Cl) into hexane containing trioctylphosphine oxide has been examined. The data are explained by assuming LnX3•3E and LnX3•4E as being the extracted species. The proportion of LnX3•4E decreases and that of LaX3•3E increases from light to heavy lanthanoids. The extraction constants for LnX3•4E are independent of the lanthanoids, and the constants for LnX3•3E are dependent on the lanthanoids. The separation factor in the hexane system is much smaller than that in chloroform over the series of lanthanoids. The difference is explained in terms of the different extracted species; the dominant species in hexane is LnX3•4E in the light lanthanoids, while the dominant species in chloroform is LnX3•3E over the series.
    Download PDF (245K)
  • Dongjin PYO, Doweon Ju
    1994 Volume 10 Issue 1 Pages 171-174
    Published: February 10, 1994
    Released: July 04, 2006
    JOURNALS FREE ACCESS
    The polarity range of solutes that can be separated by supercritical fluid chromatography (SFC) can be greatly extended by the addition of polar modifiers to supercritical CO2. In this paper, a new mixing device was introduced, in which highly porous stainless-steel filters were used to generate water-modified or methanol-modified carbon dioxide mobile phases. When supercritical CO2 goes through the mixing device, modifiers held within the small pores of filters can be dissolved in the pressurized supercritical fluids. Among the many stainless-steel filters with different porosities which
    were tested, 0.5 and 2μm stainless-steel filters were more effective than the others. To measure the amount of modifiers dissolved in supercritical CO2 after the mixing device, a modifier sensor which consists of a polymer film, i.e. a film of a perfluorosulfonate ionomer (PFSI), was used.
    Download PDF (249K)
  • Shaojun DONG
    1994 Volume 10 Issue 1 Pages 175-177
    Published: February 10, 1994
    Released: July 04, 2006
    JOURNALS FREE ACCESS
    Amperometric biosensors based on surface modifications of electrodes are described. Cobalt porphyrins modified on glassy carbon and carbon fiber electrodes can greatly decrease the overpotential and increase the sensitivity of detection due to EC electrocatalysis. Cation exchange polymer films, Nafion and Eastman Kodak AQ, as well as poly(1, 2-diaminobenzene) film, were used as membrane barriers; they can avoid the interference from ascorbic acid and uric acid. Simple ferrocene without any substitutes was incorporated in Nafion film for preparation of glucose sensor; it shows long term stability because of two domains (hydrophilic and hydrophobic) existed in the film. By using ferrocene derivatives as mediator, amino acid enzyme electrode was fabricated with double-enzymes. Dehydrogenase (lactic acid, alcohol and malic acid dehydrogenase) enzyme electrodes were prepared with double-mediators. This kind of biosensor can overcome the disadvantage of poor selectivity and reproducibility by using the mediators for direct determination of NADH.
    Download PDF (177K)
  • Y. S. FUND, S. Y. Mo
    1994 Volume 10 Issue 1 Pages 179-180
    Published: February 10, 1994
    Released: July 04, 2006
    JOURNALS FREE ACCESS
    A recent advance in square-wave voltammetry provides a method which can perform potential scanning within seconds, and is thus applicable for detection in a flow system. Although square-wave voltammetry has been applied to the flow injection analysis of additives in food, theoretical work has been lacking in the literature. This paper presents a working equation for the above-mentioned analysis. The results obtained by a theoretical calculation have been shown to give satisfactory agreement with the experimental results. The results for analyses of food are given to illustrate the applicability of the technique for flow injection analysis.
    Download PDF (141K)
  • Hitoshi HOSHINO, Kyouko KIBA, Shinsuke EDA, Takao YOTSUYANAGI
    1994 Volume 10 Issue 1 Pages 181-185
    Published: February 10, 1994
    Released: July 04, 2006
    JOURNALS FREE ACCESS
    The near-infrared (NIR) color forming reagents are described for Ni, Pd, and Pt ions, π-electron conjugated 1, 2-dithiols and 1, 2-diamines. The dithiol ligands forms the yellow 1:2 chelates with these metal ions and subsequent oxidation with I2 or IO3- ion yields the corresponding NIR active species. The spectroscopic data are: Ni-tcbt, λ=878nm (ε=1.49×104M-1 cm-1); Pd-tcbt, λ=1125nm (ε=2.00×104); Pt-tcbt, λ=880nm (ε=1.92×104), where tcbt means 3, 4, 5, 6-
    tetrachlorobenzene-1, 2-dithiol. In contrast with the dithiolato chelates, the complexation and oxidation processes for metal-diamine systems are concurrently accomplished under slightly acidic (for Pt ion) or slightly alkaline (for Pd ion) conditions, respectively. Very large E values are obtained: Pd-Br2dab, λ=828nm (ε=4.54×104); Pt-Br2dab, λ=738nm (ε=1.29×105), where Br2dab denotes 3, 5-dibromo-1, 2-diaminobenzene. A new idea for designing unique NIR color formation systems is reported; the complexation reactions must be linked with reduction-oxidation processes. The satisfactory selectivity of the Br2dab system for Pt in the presence of iron, copper, and zinc ions is demonstrated for Pt determination in possible clinical practices.
    Download PDF (351K)
  • Shoji MOTOMIZU, Masanori KOBAYASHI
    1994 Volume 10 Issue 1 Pages 187-192
    Published: February 10, 1994
    Released: July 04, 2006
    JOURNALS FREE ACCESS
    New precipitation reactions for alkali metal ions are proposed. The crown ether complexes of alkali metal ions were found to be less soluble than the alkali metal ions, themselves, in water when they form ion-association complexes with a bulky anion, such as the Hexyl ion (Hexyl-: 2, 4, 6, 2′, 4′, 6′-hexanitrodiphenylaminate ion) and its analogues as a counter ion. The apparent solubility products (Ksp) of alkali metal ions were determined in aqueous solutions. On the basis of the precipitation reaction, a flow-injection (FI) method for the spectrophotometric determination of potassium ions in water samples is proposed. A double-line FI system was assembled, and samples were injected into a carrier stream, which merged with a reagent stream containing bulky anions, a crown ether, EDTA and saturated potassium ions. Calibration graphs with Hexyl- and DC18C6 (dicyclohexano-18-crown-6) as well as with α-Hexyl(2, 4, 6-trinitrophenyl-2′, 4′-dinitronaphthylaminate ion) were linear over the range 2×10-6-1×10-4M (M=mol dm-3) and 1× 10-7-1×10-5M potassium ion, respectively.
    Download PDF (360K)
  • Shih-Yi CHANG, Tai-Ly TSO
    1994 Volume 10 Issue 1 Pages 193-201
    Published: February 10, 1994
    Released: July 04, 2006
    JOURNALS FREE ACCESS
    A portable open long-path Fourier-transform infrared system (POPFT-IR) operable at pathlengths of up to 961m has been constructed for the detection and measurement of trace gases in ambient air and for photochemical smog formation studies. The long optical path is achieved by using a three-mirror multiple reflection cell with a 15.5m base path. The combination of a retro-reflection mirror with one of three mirrors eliminates any air-turbulence interference. The design, construction, advantage, and use of this novel folded open-path optical system and calibration spectrum for quantitative analysis are described in detail. Preliminary ambient air measurements were made at a variety of locations in Taiwan from urban, suburban and rural to remote areas. The existing trace gases in the background atmosphere were measured as nitrous oxide (N2O), methane (CH4), carbon monoxide (CO) and carbon dioxide (CO2). Major pollutants such as ethylene (C2H4), propylene (C3H6), ammonia (NH3), ozone (O3) and peroxyacetyl nitrate (PAN) were measured in the polluted urban atomosphere.
    Download PDF (616K)
  • Xing-Zheng WU, Hiroaki SHINDOH, Masaaki YAMADA, Eigo KOBAYASHI, Toshiy ...
    1994 Volume 10 Issue 1 Pages 203-205
    Published: February 10, 1994
    Released: July 04, 2006
    JOURNALS FREE ACCESS
    A novel detector for flow injection analysis has been developed based on the optical beam deflection induced by the chemical reaction heat. A new flow cell was designed, in which the lower part is filled with CCl4 and an HCl solution is flowed above the CCl4 phase. An NaOH solution is injected into the flow line to react with the HCl. The neutralization heat is transferred to the CCl4 phase, thus generating a temperature gradient. This temperature gradient induces a refractive index gradient which, in turn, generates a deflection of a probe beam that is passed through the CCl4 phase. The effects of the flow rate and the length of the cell on the deflection signals have been investigated. The deflection signal was found to be proportional to the concentration of NaOH in the range of 0.05 to 0.5mol/l by using the flow cell. The detection limit of the NaOH concentration was about 0.05mol/l. Another type of the flow cell is also discussed.
    Download PDF (169K)
  • Norio TESHIMA, Hideyuki ITABASHI, Takuji KAWASHIMA
    1994 Volume 10 Issue 1 Pages 207-212
    Published: February 10, 1994
    Released: July 04, 2006
    JOURNALS FREE ACCESS
    A new simultaneous flow injection determination of vanadium(IV) and vanadium(V) has been proposed with photometric detection. The method is based on the effect of ligands on the formal redox potential of the iron(III)/iron(II) system. The potential of the redox system increases due to the presence of 1, 10-phenanthroline (phen); vanadium(IV) is thus easily oxidized by iron(III) to vanadium(V), producing an Iron(II)-phen complex (λmax=510nm). On the other hand, the presence of diphosphate causes an increase in the reducing power of iron(II) because of a decrease in the potential of the system. Thus, the reduction of vanadium(V) by iron(II) takes place easily. By using an FIA system and measuring the absorbance of the complex at 510nm, the simultaneous determination of vanadium(IV) and vanadium(V) is possible based on both reactions. The proposed method makes it possible to obtain both positive and negative FIA peaks corresponding to the concentrations of vanadium(IV) and vanadium(V) alternatively by a single injection of the sample solution. Vanadium(IV) and vanadium(V) at the 10-6mol dm-3 level can be determined at a rate of 30 samples h-1(60 peaks h-1).
    Download PDF (355K)
  • Yoshiaki KURAUCHI, Takayuki YANAI, Naoyoshi EGASHIRA, Kazuya OHGA
    1994 Volume 10 Issue 1 Pages 213-217
    Published: February 10, 1994
    Released: July 04, 2006
    JOURNALS FREE ACCESS
    A fiber-optic sensor having a chitosan/poly(vinyl alcohol) blended membrane as the cladding and a Teflon protective coating was fabricated to determine ethanol in alcoholic beverages. The response was explained on the basis of an increase in the critical angle of the optical fiber by ethanol, which was induced by a shrinkage of the cladding membrane, leading to an increase in the refractive index. Crosslinking of the cladding membrane with glutaraldehyde enhanced the sensor sensitivity in the 0-70v/v% ethanol-content range. The Teflon coating removed interferences from sugars and organic acids commonly present in alcoholic beverages. The response time was within 2min for 50v/v% ethanol and the relative standard deviation was within 1.7% in 20 repeated determinations during a 2-week period. A linear relationship was obtained between the response and the ethanol content in the 0-70v/v% range. The sensor was applied to the determination of ethanol in shochu, sake, wine, whiskey and beer and the results were consistent with the certified values and values obtained by the conventional specific-gravity method.
    Download PDF (323K)
  • Teiichiro OGAWA, Hangting CHEN, Kazuhiro MASUDA, Takanori INOUE
    1994 Volume 10 Issue 1 Pages 219-221
    Published: February 10, 1994
    Released: July 04, 2006
    JOURNALS FREE ACCESS
    The laser two-photon ionization technique has been applied to several aromatic molecules on the surface of water in ambient air. The third harmonic of a NdYAG laser (355nm) was used for excitation and ionization. The photoionization charge (the area of the signal) was linearly proportional to the solute concentration when the incident angle of the laser beam was 85°. Less soluble molecules exhibited larger signals when the molar absorptivities were
    equal. The detection limits of aminoanthracene and methylanthracene were 0.2μg/dm3 (ppb). They are almost identical to those obtained at 337nm, but slightly inferior to those obtained in hexane solution.
    Download PDF (193K)
  • Tadashi HARA, Syuji KAYAMA, Hisashi NISHIDA, Riichiro NAKAJIMA
    1994 Volume 10 Issue 1 Pages 223-225
    Published: February 10, 1994
    Released: July 04, 2006
    JOURNALS FREE ACCESS
    Download PDF (175K)
feedback
Top