Search Results

You are looking at 1 - 10 of 18 items for

  • Author or Editor: Y. Nakano x
  • All content x
Clear All Modify Search

Abstract  

Concentration levels of trace elements were determined in several speciesof subtropical crustaceans from Amami Islands in Japan in order to evaluatethe levels of specific accumulation of elements among species. Tissue samplesprepared from gill, muscle, hepatopancreas, and testis were irradiated forphoton activation analysis (PAA) and neutron activation analysis (NAA). ByPAA and NAA, eighteen elements could be determined. The levels of Br and Iwere extremely high in gills of spiny lobster and shovel-nosed lobster, respectively.A high concentration of Ag was found in the hepatopancreas of spiny lobsterscollected from the Amami Islands, while this element was not detected in thesame species collected from Toba. The results suggest that the distributionof the trace elements in different tissues and species varies according toboth species and environmental differences. To study the molecular forms ofthe elements in tissue, we separated fractions that contained protein-boundelements from the hepatopancreas of spiny lobsters by ultracentrifugationand gel filtration chromatography. Elution profiles of the chromatographysuggest that Cu, Fe, and Se were bound to proteins, while Ag was not.

Restricted access

Abstract  

Instrumental neutron activation analysis was applied to 61 ivory samples of which origin countries are known. 12 elements such as Br, Ca, Cl, Co, Cs, Fe, Mg, Mn, Na, Sc, Sr and Zn, were determined in all samples. The factor score of each sample was calculated for each factor by making use of principal component analysis in order to determine their origins. The results were compared with those by stable isotope analysis (13C and15N).

Restricted access

Abstract  

Marine invertebrates are well known to accumulate trace metals from seawater, plankton, sea plants, and sediments. To test the usefulness of such organisms as a bio-indicator of environmental conditions, we have determined levels of trace elements in tissue of twelve species of marine invertebrates by photon and neutron activation analysis. Relatively higher concentration of elements were observed for Ni and Sn in mid-gut gland, for Cu and Zn in oyster tissues, for Se in swimming crabs, for Cu, Fe, and Se in gills of swimming crabs. Our results indicate that mid-gut gland of ear-shell will be useful as the indicator of environmental conditions.

Restricted access

Abstract  

Trace elements in soft tissues of marine bivalves were determined by neutron activation analysis (NAA) and photon activation analysis (PAA). Elemental levels of Ag, As, Br, Co, Cu, Fe, I, Mn, Ni, Rb, Se, and Zn in the organs of giant ezoscallos, rock oysters, and giant crams were obtained. The metal-bound proteins were extracted from the mantles and hepatopancreases of rock oysters. By irradiating the fraction obtained by HPLC gel chromatography, we found the possibility for the existence of an Ag bound protein in the mantles.

Restricted access

Abstract  

Instrumental neutron activation analysis was applied to 80 samples from various African countries and 81 samples from the Kruger National Park in the Republic of South Africa. Twelve elements such as Br, Ca, Cl, Co, Cs, Fe, Mg, Mn, Na, Sc, Sr, and Zn, were determined in all samples. The factor scores of each sample were calculated from those elemental concentrations for the first and second factors to clarify the differences of samples from various African countries with those from Kruger Park. The results were compared with those by stable isotope analysis (13C and15N).

Restricted access

Abstract  

An experimental method is described for the synthesis of195mPt-radiolabeled cis-diammine (glycolato) platinum (II) (254-S). Ten mg of 95% enriched194Pt was irradiated for 75 h in the hydraulic conveyer of KUR at a thermal neutron flux of ca. 8.15×1013 n·cm–2·s–1, and the195mPt-radiolabeled 254-S was synthesized and purified using HPLC (column: Dichrosorb Diol, elution: 80% CH3CN). The chemical yield was approximately 45%, with chemical purity greater than 98.4%. The radionuclidic purity was nearly 100% and the specific activity, 7.2 MBq·mg–1 254-S.

Restricted access

A combination system of thermogravimetric/differential thermal analysis (TG-DTA) and Fourier-transform infrared absorption spectroscopy (FT-IR) was described. This simultaneous TG-DTA/FT-IR technique gave spectroscopic and weight loss information about the thermal degradation process of engineering polyesters; poly(ethylene terephthalate)(PET) and poly(butylene terephthalate)(PBT). The evolved gases from PET were benzoic acid, carbon dioxide and carbon monoxide, while those from PBT were terephthalic acid esters and benzoic acid esters.

Restricted access

Abstract  

Samples of hair from 370 subjects were analysed by neutron activation. The samples were taken from residents of nine different countries: Japan, France, Ivory Coast, Brasil, Paraguay, Canary Islands, Papua New Guinea, Italy and New Zealand. The selenium determination was made using the76Se(n,)77mSe reaction.It was found that the average selenium concentration in the hair of Japanese subjects, both those living in Japan and those living in foreign countries was higher (total average: 0.59±0.14 mg/kg) than those of subjects from other countries (total average: 0.42±0.13 mg/kg).Our results from the determination of the selenium concentration in the hair of individuals from different countries show significant differences between different countries, nevertheless, the selenium content in human hair was small amounts. Since this is likely due to differences in diet. This method was able to analyze quickly for many samples.

Restricted access

Abstract  

Human hair collected from the mercury, arsenic and cadmium polluted areas has been analysed by instrumental neutron activation method. The concentrations of 27 elements were compared with those of normal Japanese. Correlation coefficients of logarithmic concentrations between the elements were calculated and their significance levels were determined. Factor contribution and factor loadings of the elements were calculated for each factor by making use of principal component analysis. The factor score of each sample was also calculated for each factor to examine the effects of the contamination by heavy metals on individuals.

Restricted access

Abstract  

The detection of tritium and14C-ethylene on the surface of nickel sheet was carried out by means of autoradiography. Two autoradiographical methods were used, the ordinary stripping-film method and the electron-microscope autoradiographical method. The ordinary autoradiographs indicated that14C-ethylene accumulates at scratches on the surface of the sheet; however, tritium accumulates at grain boundaries and scratches. Electron-microscope autoradiographs indicated that tritium accumulates on the step-edges of slip band of nickel.

Restricted access