| Project/Area Number |
12680531
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Environmental dynamic analysis
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| Research Institution | Japan Women's University |
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Principal Investigator |
ARIKAWA Yoshiko Japan Women's University, Fac. of Science, Professor, 理学部, 教授 (00060666)
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| Co-Investigator(Kenkyū-buntansha) |
IMAIZUMI Yukiko Japan Women's University, Fac. of Science, research assistant, 理学部, 助手 (10247091)
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| Project Period (FY) |
2000 – 2002
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| Project Status |
Completed (Fiscal Year 2002)
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| Budget Amount *help |
¥3,600,000 (Direct Cost: ¥3,600,000)
Fiscal Year 2002: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 2001: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 2000: ¥2,300,000 (Direct Cost: ¥2,300,000)
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| Keywords | sulfur isotopic ratio / carbonylsulfide / dimethylsulfide / environmental movement / acidification / isotope measurement / DMS generation algae / Thiobacillus thioparus / DMS / 藻類 / 光触媒シリカゲル / 大気中二酸化硫黄 / 浮遊粒子状物質 / 三宅島火山噴火 / δ^<34>S値 / 動態解析 / 環境硫黄 / 環境の酸性化 / 酸性雨 / 硫黄同位体化 / 自然起源硫黄 / COS / DMSの捕集 / Tenax樹脂 |
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| Research Abstract |
Carbonyl sulfide(COS) is produced by microbes such as Thiobacilius thioparus under the presence of thiocyanates in soil. On the other hand dimethly sulfide(DMS) is produced in the sea by algae and the sulfur in the compound comes from the sea water sulfate. In both cases microbes use inorganic sulfur to generate COS and DMS. Why they don't use organic sulfur? To elucidate this problem the experimental generation of COS and DMS were examined by adding organic sulfur compounds in the medium. In the case of cultivating Thiobacillus thioparus by adding aryl isothianate as organic sulfur, microbes did not breed. For DMS it took long times to find algae which breed effectively in the laboratory. Cricosphaera roscoffensis NIES 8 and Alexandrium catenella NIES 677 were recognized to generate DMS in the sea water medium experimentally.
The predominant means to identify the origin of sulfur in the compounds is isotopic (^<32>S/^<34>S) measurement. For the isotopic measurement the collection method of COS and DMS were investigated. COS was introduced in ethane, added by Zn(CH_3COO)_2 to form ZnS which is converted to Ag_2S. DMS was adsorbed on silica gel with titanium oxide photo catalyst which is then irradiated by ultraviolet ray(350〜380nm). The formed SO_2 is introduced to hydrogen peroxide solution to be oxidized to SO_4^<-2> which is finally converted to Ag_2S. The sulfur isotopic measurement is carried out for SO_2 formed from Ag_2S described above. For COS isotopic fractionation by microbe metabolism was observed. δ^<34>S value (6.1‰) of thiocyanate sulfur as a standing material went to be lower as 3.8‰. This result is expected to be useful for the discussion of behavior of environmental sulfur.
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