Shigeyuki Tanaka

Selective preconcentration of Au(III), Pt(IV) and Pd(II) on silica gel modified with γ-aminopropyltriethoxysilane

Abstract Silica gel functionalized by reaction with γ-aminopropyltriethoxysilane was prepared and its adsorption characteirstics for metal ions were studied. This material selectively removes the Au(III), Pt(IV) and Pd(II) chloro complex ions from sample solutions containing Fe(III) and Cu(II) ions by ion exchange.

Preconcentration of indium with 1-phenyl-3-methyl-4-stearoyl-5-pyrazolone on silica gel

Abstract Indium was quantitatively retained at pH > 2.8, and could be removed by treatment with 1 M hydrochloric acid. The adsorption capacity of the material was 32 μmol In g −1 . Nickel, cobalt and zinc had no effect on the retention of indium.

Selective determination of l-ascorbic acid by a chemiluminescence method with ascorbate oxidase

Abstract The determination of l -ascorbic acid by utilizing lucigenin chemiluminescence with ascorbate oxidase was studied. The dehydroascorbic acid produced by the enzymatic reaction of l -ascorbic acid and ascorbate oxidase was found to be a more effective activator than l -ascorbic acid for the lucigenin chemiluminescence reaction. The optimum pH, temperature and incubation time for the enzymatic reaction were 5.7, 30°C and 10 min, respectively. The calibration graph was linear over the range 0.14–50 μg ml −1 . The correlation coefficient for this line was 0.998. The detection limit (2σ) was 0.1 μg ml −1 and the relative standard deviation was 10% ( n = 5) for a concentration of 0.14 μg ml −1 . This method was applied to the determination of l -ascorbic acid in commercially available drugs and health drinks.

Determination of acetaldehyde by a chemiluminescence method

Abstract The determination of acetaldehyde was achieved by monitoring the chemiluminescence emission from the luminol-potassium hexacyanoferrate (III) reaction in the presence of xanthine oxidase. The linear range was three orders of magnitude, the detection limit (2σ) was 4 × 10 −7 M and the relative standard deviation ( n = 5) was 10.6% for 4.3 × 10 −7 M. No interference was observed from seven organic and inorganic species at a 1000-fold excess relative to a concentration of 1 × 10 −5 M acetaldehyde.

Fourier Transform Infrared Emission Measurements By Exciting With A Laser

Infrared emission spectroscopy(EMS) has been known as an useful method for analysing thin organic films on metal substrates which have high reflectivity[1,2]. However, it is difficult to obtain spatial resolution of a specimen, since the measurement by the conventional method is carried out by heating the sample above detector temperature using an electrical heating equipments. In this paper, a laser excitaion method was examined instead of using an electrical heater. The emission spectra of organic compounds on aluminum plates were measured by illuminating the specimen continuously with a laser beam, and the results were comapred with the spectra obtained by a conventional heating method. Preliminary results obtained by a step scan FT-IR spectrometer and a modulated laser beam were also discussed.

In-situ measurement of photochemical changes of solid samples by fourier transform infrared photoacoustic spectroscopy

Infrared spectral changes of lithographic printing plates were measuredin-situ by PAS and RAS. The advantages of PAS over RAS were discussed for the spectral measurements of organic coatings on roughened metal surface.