The combinations of some oxidases and appropriate reducing agents lead to effective substrates regeneration cycles via enzymatically oxidized products and/or enzymatic intermediate complex accompanied by amplified change in enzymatic oxygen consumption. These chemically amplified reactions were extremely useful for enhancement of output signal of oxygen-detection type of enzyme sensors for highly sensitive detection of not only substrates but also enzymatic inhibitors and cell population. Furthermore, novel oxidase-mimic reaction, in which reducing agents are oxidized by dissolved oxygen, catalyzed by metal-proteins, poly (amino acid) /metal complex and DNA/metal complex could be applied for highly sensitive biosensors for exogenous ligands and DNA-binding drugs.

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Electrolytic dissociation of water is accelerated by metal oxide hydrates incorporated in a bipolar membrane. In order to clarify the mechanism of catalytic effect, bipolar membranes incorporated with Al (III) -, Rh (III) -, Zr (IV)- and Ta (V) oxide hydrate were prepared and current density-potenti al difference curves were measured across these membranes. The current density increased by the treatment with these metal oxide hydrates and is dependent on the molar ratio [OH^-]/[Mⁿ⁺] (Mⁿ⁺ =Al³⁺, Rh³⁺, Zr⁴⁺, Ta⁵⁺). These results suggest that water molecules coordinated to metal ions play an important role in the dissociation of water in the bipolar membrane.

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In the initial stage of corrosion of steel, both corroded and bright areas were observed on a steel surface in aqueous NaCl solution under the aeration. The corroded area grew with time. The relationship between corrosion potential (E_corr) and θ at 25°C was studied; θ is defined as the ratio of the corroded area (A_a) to the total area (A). The electrochemical roles of bright and rusted surfaces on a steel were discussed.
In the initial stage of corrosion, the relationship between E_corr, and log[θ/ 1-θ] was linear with the slope of about 130 mV/decade, regardless of the concentration of NaCl and pH. This relation was explained on the following assumptions; (a) an anodic reaction proceeds mainly under the rust, while a cathodic reaction does on the bright surface, (b) the anodic reaction rate does not depend on the potential. The corrosion reaction could be controlled by the anodic reaction in the initial stage of corrosion.

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Vapor phase adsorption behavior of hexane, benzene, ethanol, and water to films of polyfluorinated surfactants, N-methyl-N, N-dioctadecy1(3-perfluoroacylamino)propylammonium bromide having three different number of carbon n=1, 2, 3 in the perfluoroalkyl group, and to films of corresponding three hydrocarbon analogues were studied by quartz crystal microbalance method. The surfactant films were made by casting them on gold plated on quartz crystals. Adsorption-desorption equilibrium constant, number of adsorption site, adsorption rate constant, and desorption rate constant were determined. Nonpolar hexane and benzene were observed to be readily adsorbed and desorbed, while polar ethanol and water had slower adsorption and desorption rate constants. The larger number of adsorption site and the total area of adsorption suggested that polar ethanol and water adsorbed to ammonium and amide groups of the surfactants in a similar mechanism of solvation. The casted films of polyfluorinated surfactants have been suggested to have partly the similar surface polyfluorinated micro-structure with those reported in polyfluorinated micelles and vesicles, while the films of hydrocarbon type surfactants had micro-structure where ammonium groups were directly exposed to gas phase.

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The homogeneous hydroformylation of styrene catalyzed by dihydridorhodium complex [RhH₂ (Ph₂N₃) (PPh₃)₂] with synthesis gas (CO/H₂O = 1/1) was carried out in dimethyl sulfoxide. The synthesis gas pressure was in the range from 9.8×10⁴ to 9.8×10⁵ Pa, and the temperature was changed from 303to 333 K. The products were 2- and 3-phenylpropanal, 2-phenylpropanal being more abundant. Increase in the pressure of synthesis gas and addition of 1, 3-diphenyltriazene or triphenylphosphine increased the yield of 2-phenylpropanal and decreased 3-phenylpropanal. When the reaction temperature was raised, 2-phenylpropanal yield reached maximum at 323 K, and then it decreased gradually. On the other hand, the formation rate of 3-phenylpropanal was accelerated by elevating the reaction temperature. The mechanism of hydroformylation reaction was discussed.

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Low-pressure helium ICP-MS provides some advantages including effective ionization, negligible spectral interference and low consumption of plasma gases. The conventional nebulizers, however, are not useful for introducing aqueous sample solutions. In the present study, therefore, hydride generation was examined as a sampling technique for the determination of selenium. Traces of selenium in a stream (0.5 mL min^-1) of aqueous solution were converted into selenium hydride in coiled PVC tubes (4 mm i. d.×0.5 m and 4 mm i. d.×1.5 m) with 2 mol dm^-3 HCl and 1 w/v% NaBH₄ aqueous solution. The volatile hydride was separated from the solution and transferred into a low-pressure helium ICP through a glass capillary tube (0.2 mm i. d.×40 mm) with the aid of helium carrier gas at a flow rate of 100 mL min^-1. The mass spectra obtained show that ⁸⁰Se⁺ (generated from the most abundant isotope)is successfully determined with the excellent S/B ratio, otherwise not measured as is the case with conventional argon ICP due to serious isobaric interference.

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In order to develop an effective adsorbent for nitrate anion from ground water, four kinds of chitosan derivatives containing the primary amine (CLC), the secondary amine (GCLC), the quaternary ammonium (TMC) and the quaternary ammonium (NTMC) imprinted for nitrate anion were synthesized. These adsorption properties for various anions such as nitrate anion, chloride anion, and sulfate anion were examined by a batchwise method at 303 K. The pH dependencies on the adsorption properties were tested in the adsorption from a single solution containing only nitrate anions. CLC and GCLC exhibited a maximum adsorption of nitrate anions in the pH region of 3-4, while these hardly adsorbed it in the region of pH around 7. On the other hand, the quaternized chitosan derivatives exhibited a high adsorption for nitrate anions even at pH 7, especially, NTMC indicated two times adsorption compared with TMC, owing to a molecularly imprinting effect. This effect has appeared in the adsorption from a solution containing a single solute, while the effect hardly appeared in the adsorption from the mixture solution containing nitrate anion, chloride anion and sulfate anion.

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The 13 samples, which contained 8 samples of accurate methamphetamine. HCl (Me) content and 5samples of unknown Me content, were measured by FT-IR. The absorbance of each wavelength was divided by the absorbance of the 700.1 cm^-1 wavelength and the 20 values from one sample were selected by Quantification N. The correlation coefficient between each of the 20 values (categories) and Me content was calculated from the 8 samples of accurate Me content using a correlation equation. The 9categories showed a correlation coefficient of over 0.900 and they were used for the determination of the Me content by the improved principal component score analysis (PCS2), principal component regression (PCR), partial least squares regression (PLS), and multiple regression analysis (MRA). The principal component analysis (PCS) using 20 categories and MRA using 9 or 20 categories were unsuitable for the determination of the Me content. The PCS2 method provided an accurate and precise quantitative analysis of the Me content.

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Stable sulfur isotope ratios of SO₂ emitted from active volcanoes such as Mt. Sakurajima and SatsumaIwojima were determined in relation to the project clarify source of sulfur in acidic and oxidative compounds in East Asia. The δ³⁴S of SO₂ were +10.1 to + 13.5‰ and +3.2 to +8.4‰at Satsuma-Iwojima and Mt. Sakurajima, respectively. We reported the δ³⁴S values for Mt. Sakurajima for the first time, but it should be noted that the gas samples were collected at station about 3 km away from fumarole. Nevertheless the OS values of Mt. Sakurajima volcano were similar to those from Mt. Use, Mt. Tarumae, Mt. Kuju-Iwoyama and Mt. Aso for which gas samples directly collected from fumarole.
The δ³⁴S values of sulfate in wet deposition collected at Mt. Shibi and Yorita, located approximately 50 km northwest of Mt. Sakurajima volcano, varied with time, contribution of the different sources of sulfur to these two sampling localities. Wet deposition samples from Mt. Shibi were considered to be more influenced by Mt. Sakurajima emission than Yorita, which was rather affected by continental anthropogenic emission.

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To get more information concerning zeolite synthesis in the presence of 1-butanol (n-BuOH), influences of the alkali metal cation and the synthesis conditions on the zeolite synthesis were investigated. It was found that highly crystalline TON (Theta-1), MER (Merlinoite) and LTL (L) type zeolites were synthesized when KOH was employed as an alkali source, whereas MFI (ZSM-5) and MOR (Mordenite)type zeolites for NaOH. Characterization of zeolites obtained was conducted using X-ray diffraction, scanning electron microscopy, FT-IR, thermal analysis, ¹³C and ²⁷Al MAS NMR. From the results of FT-IR and ¹³C CP MAS NMR measurements of as-made zeolites, it was concluded that n-BuOH molecules were occluded in the zeolitic pores of TON and MFI type zeolites, while no n-BuOH molecules for MOR, MER and LTL type zeolites.

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