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Volume 44, Issue 5
Displaying 1-11 of 11 articles from this issue
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Tokuji IKEDA1995 Volume 44 Issue 5 Pages 333-354
Published: May 05, 1995
Released on J-STAGE: June 19, 2009
JOURNAL FREE ACCESSThe historical development, present, and future prospects of enzyme-modified electrodes are described with emphasis on their significance in methods of electrochemical analysis. First, the bioelectrocatalytic function of electrode systems with the enzymes solubilized in solution and immobilized on electrodes are mentioned. Then, methods for immobilization of enzymes, kinds of enzymes utilized, biosensor functions, and the proteins and microorganisms used as biocatalysts are described.View full abstractDownload PDF (3633K) -
Yuta YOKOI, Chiyo MATSUBARA, Kiyoko TAKAMURA1995 Volume 44 Issue 5 Pages 355-362
Published: May 05, 1995
Released on J-STAGE: January 18, 2010
JOURNAL FREE ACCESSA rapid and sensitive flow injection analysis (FIA) with spectrophotometric detection by a titanium(IV)-porphyrin reagent was examined for the continuous determination of glucose, sucrose, maltose and lactose in foods using immobilized enzyme reactors to yield hydrogen peroxide. A sample solution is carried by valve to three hydrolysis enzyme reactors in the flow system. The reagent is an aqueous solution of oxo[5, 10, 15, 20-tetra(4-pyridyl)porphyrinato]titanium(IV), TiO(tpypH4)4+, which reacts with hydrogen peroxide to form a monoperoxo complex, TiO2(tpypH4)4+, having an absorption peak at 450nm. The hydrogen peroxide produced from each sugar was determined by combining the reactions with glucose oxidase (GOD) and hydrolytic enzyme reactors corresponding to each sugar. Linear relations were observed between the peak heights and sugar concentrations in samples containing 0.5500μM (1010000 pmol/test) glucose, and 11000 μM (2020000 pmol/test) sucrose, maltose and lactose. The relative standard deviations for ten replicate determinations of glucose, sucrose, maltose and lactose were 0.74, 0.75, 0.84 and 0.49%, respectively, for each standard solution of 100μM. The method permitted analysis of 20 kinds of sugar in samples per hour. This method was applied to determining these four sugars in foods such as milk, soft drinks and wine with satisfactory results.View full abstractDownload PDF (1184K) -
Takashi SAITO, Nobuhiro MURATA1995 Volume 44 Issue 5 Pages 363-367
Published: May 05, 1995
Released on J-STAGE: January 18, 2010
JOURNAL FREE ACCESSA new method for colorimetric determination of trace iron ion has been studied using polyvinyl chloride(PVC) membrane containing 4, 7-diphenyl-1, 10-phenanthroline (bathophenanthroline) and ο-nitrophenyloctylether(ο-NPOE). A sheet of PVC membrane consisting of 1.0 wt% bathophenanthroline and 65.0 wt% ο-NPOE was sandwiched between a PTFE board (1×5cm) with a hole (0.39cm diameter) and another without hole. A 10cm3 of aqueous sample containing iron ion was placed in a glass beaker, and 1.0cm3 of L(+)-ascorbic acid, potassium chloride and acetic acid-sodium acetate buffer solution (pH 5.0) were added. After 16μl of the sample solution was taken by microsyringe and dropped into the hole on the PTFE board, the PTFE board was put in an oven for a definite time at 55°C. The absorbance of the colored spot portion was measured at 538nm using a spectrophotometer, and the iron ion concentration in the sample solution was determined using a calibration curve. The determination range for iron ion was 2.04×10-6 to 8.15×10-4 mol dm -3. The reproducibilities of the absorbance values for samples containing 3.3×10-5 and 1.0×10-4 mol dm -3 of iron ion were 0.049± 1.95×10-3 and 0.16 ± 4.4×10-3 for a 3.9 and 2.8% relative standard deviation (n = 10), respectively.View full abstractDownload PDF (761K) -
Osamu FUJINO, Masakazu MATSUI1995 Volume 44 Issue 5 Pages 369-376
Published: May 05, 1995
Released on J-STAGE: January 18, 2010
JOURNAL FREE ACCESSDetermination, uptake and distribution of various ions such as alkali metals in three different parts (leaf, stem and root) and seeds of radish (Kaiware daikon) were examined using flame emission spectrometry and ICP-AES. In order to examine the influence of concentration alkali metal ion concentration in the radish culture solution on the uptake and distribution of these metals, the radish was grown at pH 5.6 in solutions containing alkali metal chloride at concentrations ranging from 10-5to 10-1mol dm-3. When the radish were grown in culture solution with alkali metal ions of low concentrations (10-5and 10-4mol dm-3), Na, K, Rb and trace Li were detected in leaves, stems and roots while Cs was scarcely detected. However, the contents of Na, K, Li in these organs were the same as those in radish cultivated in pure water. An increase of Rb uptake was observed with an increased Rb concentration. In the case of high concentrations (10-3and 10-2mol dm-3) of alkali metals in culture solution, the all alkali ions uptake of all alkali ions suddenly accelerated. Moreover, at concentrations higher than 0.1 mol dm-3, the radish germinated poorly and did not completely mature.View full abstractDownload PDF (1092K) -
Yuji SUZUKI, Yoshikatsu SAKAGISHI1995 Volume 44 Issue 5 Pages 377-382
Published: May 05, 1995
Released on J-STAGE: January 18, 2010
JOURNAL FREE ACCESSWe investigated the reaction of saccharides with six diazo-compounds :sulfanilic acid, 4-aminobenzoic acid, 3-aminobenzoic acid, 4-iodoaniline, 4-chloroaniline and 4-aminoacetophenone. Five reduced sugars, glucose, fructose, xylose, maltose and lactose, reacted with various diazo-compound to form colored products under alkaline conditions; a nonreduced sugar, sucrose, did not react. The absorption maximum of the colored product varied with the diazo-compound, correlating with the Hammett substituent constant of the substituent attached to the benzene ring on the aromatic primary amine, but there was little difference in the absorption spectra of the five sugars reacted with the same diazo-compound. Their absorption maxima ranged from 530 to 540 nm and their molar absorptivities from 216 to 649 l mol-1cm-1in the case of the reaction of diazotized 4-aminobenzoic acid, which gave the colored product with the largest color intensity. The absorption spectrum of the colored product indicated a reversible change when hydrochloric acid or sodium hydroxide were added, like that of a pH indicator. In the color reaction of the reduced sugars, a lag time of 318 min was required before the color reaction began. The reaction rate of the ketose, fructose, was higher than that of glucose, xylose, maltose and lactose, the reaction time being about 60 min for fructose and about 140 min for the other reduced sugars. The colored product was easily oxidized by air after completion of the reaction, but was stabilized by addition of ascorbic acid. Since nonreduced sugar did not react with diazo-compound, it seems that the carbonyl groups formed in the reduced sugars under alkaline conditions take part in this color reaction. As this color reaction of the sugars occured at room temperature, it may be of use for their detection.View full abstractDownload PDF (746K) -
Toshiyuki MITSUI, Yoshikazu FUJIMURA1995 Volume 44 Issue 5 Pages 383-389
Published: May 05, 1995
Released on J-STAGE: June 19, 2009
JOURNAL FREE ACCESSWhen a mixture of heavy oil and kerosene was measured by GC, we could not accurately judge whether the measured material was heavy oil or kerosene because the respective chromatogram overlapped. Therefore, to analyze the blend composition ratio (v/v) of heavy oil to kerosene, some chromatograms were made using mixture of heavy oil and kerosene with blend composition ratios. Each peak in the chromatograms was expressed by a relative value to provide data for calculation by principal component analysis. The blend composition ratio of an unknown sample was calculated more finely by factor score and dispersion of principal component. By this method, the blend composition ratios of heavy oil-kerosene mixtures could be determined with a high degree of accuracy.View full abstractDownload PDF (1078K) -
Atsushi UZAWA, Wataru YOSHIMURA, Tadao OKUTANI1995 Volume 44 Issue 5 Pages 391-395
Published: May 05, 1995
Released on J-STAGE: January 18, 2010
JOURNAL FREE ACCESSAg(I) and Au(III) are adsorbed on activated carbon (AC) impregnated with dithizone (AC-Dz). A simple and rapid method for determining trace amounts of Ag(I) and Au(III) by metal furnace AAS using direct heating of metals adsorbed onto AC was investigated. To 100 cm3 of sample solutions containing less than 0.1 μg of Ag(I) and 0.5 μg of Au(III), respectively, 25 mg of AC-Dz is added. Ag(I) and Au(III) are adsorbed as Dz-complexes after adjusting the pH to 1.5 for Ag(I) and 3.0 for Au(III). After separation of AC from the aqueous phase through a membrane filter, an AC-suspension is dispersed in 5.0 cm3 of water by mixing with shaking. Then, aliquots (10 mm3) of AC-suspension are directly injected into the metal furnace, and the Ag and Au peak heights are measured under optimal instrumental operating conditions. The determination limits (S/N =3) were 0.005 μgAg/100 cm3 and 0.04 μgAu/100 cm3. Relative standard deviations were 3.2 % and 2.6 %, respectively. The proposed method has been applied to the determination of Ag and Au in riverbottom and sea floor sediments.View full abstractDownload PDF (770K) -
Toshihide IHARA, Kaoru MURATA, Yoshio SUGIMOTO, Tatsuro NAKAGAMA, Tosh ...1995 Volume 44 Issue 5 Pages 397-400
Published: May 05, 1995
Released on J-STAGE: June 19, 2009
JOURNAL FREE ACCESSMonoamide type chiral stationary phases for high performance liquid chromatography were synthesized from (S)-α-(1-naphthyl)ethylamine using a new immobilizing method. In this procedure, the silanol groups on silica gel, which hinder the interaction between sample molecules and chiral selector, were initially treated with dimethylchlorosilane. The enantioselectivity was evaluated by changing the coverage density of the chiral selectors. It was found that when the coverage density was 0.268 groups/nm2 (0.156 mmol/g), the enantioselectivity was great. This indicates that chiral selector can interact with sample molecules more efficiently without silanol interference.View full abstractDownload PDF (484K) -
Kunihiro WATANABE, Masayuki USUKI, Masayuki ITAGAKI1995 Volume 44 Issue 5 Pages 401-404
Published: May 05, 1995
Released on J-STAGE: June 19, 2009
JOURNAL FREE ACCESSA continuous extraction system consisting of a distillation flask, an extraction flask (Morton flask) containing a high speed stirrer and a Teflon phase separator was investigated. The utility of the system was examined by the separation and concentration of V(V) and Fe(III) with acetylacetone(AA).m-Xylene was selected as the extraction solvent because distillation took place at about 140°C. Fe(III) was easily extracted into the organic solvent with AA. On the other hand, V(V) was not extracted with AA without adding pentyl alcohol. Therefore, V(V) was extracted by the synergism between AA and pentyl alcohol. The effect of stirring speed was examined on the extractions of V(V) and Fe(III). The recommended procedure for the stepwise determination of V(V) and Fe(III) was as follows: A solvent mixture ofm-xylene (15 cm3)and AA(1 cm3) was added to the sample solution (50 cm3, pH 4) containing Fe(III) and V(V) in the Morton flask (200cm3) containing a stirring rod and a Teflon phase separator. The stirring speed was kept at 1800 rpm. The rate of solvent-transport by the Peristaltic pump was regulated at 1.6 cm3/min. The extraction was stopped after 30 min and the distillation flask containing the concentrate for Fe(III) analysis was removed. The distillation flask in the extraction-apparatus was then exchanged and 1 cm3 of pentyl alcohol and 0.5 cm3 of AA were added to the extraction solvent in the Morton flask. Subsequently, 1 cm3 of 8 mol dm-3 HCl solution was added in order to adjust the pH to 2.5. The extraction was then performed again. After 60 min, the absorbance of the concentrated extract was measured at 449 nm after dilution to 10 cm3 with m-xylene. Similarly, the amount of Fe(III) in the previous flask was determined at 437 nm. The metal ions were quantitatively extracted by the proposed method. The extractability of V(V) by this batch method was 63%. The determination ranges of V(V) and Fe(III) were 20100 μg and 1080 μg, respectively.View full abstractDownload PDF (635K) -
Yukiko IMAIZUMI, Sawako SUGIMOTO, Yoko KANAYAMA, Yoshiko ARIKAWA1995 Volume 44 Issue 5 Pages 405-409
Published: May 05, 1995
Released on J-STAGE: June 19, 2009
JOURNAL FREE ACCESSAn AAS method for the rapid and accurate determination of ppb or ppm levels of arsenic in environmental samples was developed. The method involves pretreatment by the combustion of samples in high pressure oxygen and the subsequent formation of arsine by reduction. The As2O5 formed throughout the combustion dissolves in water as As(V)O43-, which is reduced to As(III)O33- in an HCl and KI medium. Arsine generated by the reduction of As(III)O33- with NaBH4 and HCl is introduced to a quartz cell heated in an acetylene-air flame. The atomic absorption is measured at a wavelength of 193.7nm. The method of standard addition was employed for the determination of arsenic in six NIES standard samples.View full abstractDownload PDF (749K) -
Yoshiro MATSUMOTO1995 Volume 44 Issue 5 Pages 411-415
Published: May 05, 1995
Released on J-STAGE: May 25, 2010
JOURNAL FREE ACCESSGlow discharge spectrometry was applied to the determination of P and S in steel. The effect of anode inner diameter on spectral intensity, BEC (background equivalent concentration), and the analytical accuracy were studied. The inner diameters of anodes used for the experiments were 4 mm, 6 mm and 8 mm. The P and S emission intensities increased and BECs decreased with increasing anode diameter. However, the analytical accuracies were excellent in the case of the 4 mm and 6 mm inner diameter anodes.View full abstractDownload PDF (548K)
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