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Saitama, Japan

Sato R.,SI Science CO. | Kawanishi H.,SI Science CO. | Schimmelmann A.,Indiana University | Suzuki Y.,Japan National Food Research Institute | Chikaraishi Y.,Japan Agency for Marine - Earth Science and Technology
Bunseki Kagaku | Year: 2014

The availability of suitable standards (i.e., internationally calibrated reference materials) is a common issue as an analytical chemical precondition accurately measuring stable isotope ratios in many scientific disciplines. However, the traditional IAEA and NIST standards are in limited supply, particularly for the isotope analysis of organic hydrogen (D/H), carbon (13C/12C), nitrogen (15N/14N), oxygen (18O/16O), and sulfur (34S/32S). In a subproject coupled with the international project "Development of Organic H, C, and N Stable Isotope International Standards for NIST and IAEA", we recently produced new reference materials of nine amino acids. These reference martials were designed as a working standard set to cover the naturally occurring nitrogen isotopic heterogeneity, ranging from - 25 to + 45%o (δ15N value, vs. Air), which would be useful as the first internationally suitable reference materials for modern applications of the nitrogen isotope analysis of amino acids and other nitrogenous organic compounds. © 2014 The Japan Society for Analytical Chemistry.


Suzuki Y.,Japan National Food Research Institute | Isshiki M.,Food Agricultural Materials Inspection Center | Sato R.,SI Science CO. | Nakashita R.,Japan Forestry and Forest Products Research Institute
Bunseki Kagaku | Year: 2014

In previous studies, stable carbon, nitrogen and oxygen isotope analyses were probably a useful tool for tracing the geographical origin of processed eels. However, the lack of a reliable technique for isotope ratio measurements is significantly regrettable, and should be improved immediately. Here, we present results of an inter-laboratory test on the EA-IRMS determination of stable carbon, nitrogen and oxygen isotopic compositions (δ13C, δ15N and δ18O) in processed eel samples. The processed eel samples were distributed and analyzed by a total of 5 laboratories. The variations of the standard deviations for δ13C (- 18.7 ‰ ± 0.2 ‰) and δ15N (+13.4 %o ± 0.3 ‰) among laboratories were not very large compared to the instrument uncertainties. The δ18O values (+ 16.5 %o ± 3.1 ‰) in processed eel samples showed a large variation among laboratories. This may have been caused by much the contamination of N2 to the CO peak on the EA-IRMS chromatogram, and may be improved by using a longer GC column or Purge & trap columns for chromatographic separation. © 2014 The Japan Society for Analytical Chemistry.


Endo T.,Health Sciences University of Hokkaido | Hotta Y.,Health Sciences University of Hokkaido | Hisamichi Y.,Health Sciences University of Hokkaido | Kimura O.,Health Sciences University of Hokkaido | And 3 more authors.
Ecotoxicology and Environmental Safety | Year: 2012

We analyzed the δ 13C, δ 15N and δ 18O values and Hg concentration in red meat products originating from the predominant types sold in Japan for human consumption: two populations of common minke (J- and O-types), Bryde's and sei whales in the western North Pacific Ocean, and fin and Antarctic minke whales in the Southern Ocean. The order of the trophic positions, evaluated by δ 15N values and Hg concentrations, coincided with their known feeding habits: common minke (J-type)=common minke (O-type)>Bryde's≥sei≥Antarctic minke≥fin. The Hg concentrations in the combined samples from the six samples were significantly correlated with their δ 15N values (γ=0.455, n=66, p<0.05), reflecting overall differences in the trophic level. This correlation was not significant for within-species comparison for the common minke (J- and O-types) or the Bryde's whale, probably reflecting the higher δ 15N value and lower Hg concentration in the North Pacific Ocean around Japan. Determination of δ 13C, δ 15N and δ 18O could be used to discriminate between the red meat products originating from the whale species in the North Pacific and Southern Oceans. However, the four whale species or populations in the Pacific Ocean could not be discriminated on basis of these values, nor could the two species in the Southern Ocean. Positive correlations between the δ 13C and δ 15N values and negative correlations between the δ 15N and δ 18O values and the δ 13C and δ 18O values, probably reflecting migration patterns, were found in some whale species in the North Pacific and Southern Oceans. © 2012 Elsevier Inc.


Endo T.,Health Sciences University of Hokkaido | Kimura O.,Health Sciences University of Hokkaido | Sato R.,SI Science CO. | Kobayashi M.,Tokyo University of Agriculture | And 2 more authors.
Marine Pollution Bulletin | Year: 2014

We analyzed δ13C, δ15N and δ18O in the muscle and liver from killer whales stranded on the coast of Japan. The δ15N values in the muscle samples from calves were apparently higher than those in their lactating mothers, suggesting that nursing may result in the higher δ15N values in the muscle samples of calves. The δ15N value in the muscle samples of male and female whales, except for the calves, were positively correlated with the δ13C values and body length, suggesting that the increases in δ15N were due to the growth of the whales and increase in their trophic level. In contrast, the δ18O values in the muscle samples of female whales except for the calves were negatively correlated with the δ13C and δ15N values. The δ18O may be lower in whales occupying higher trophic positions (δ15N), although it might also be affected by geographic and climatic conditions. © 2014 Elsevier Ltd.

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