| Budget Amount *help |
¥4,010,000 (Direct Cost: ¥3,500,000、Indirect Cost: ¥510,000)
Fiscal Year 2007: ¥2,210,000 (Direct Cost: ¥1,700,000、Indirect Cost: ¥510,000)
Fiscal Year 2006: ¥1,800,000 (Direct Cost: ¥1,800,000)
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| Research Abstract |
(1) Quantification of cyanide
Static head-space gas chromatographic method was established for quantifying cyanide using porous polymer capillary column and nitrogen-phosphors detector, which enabled determination of ng/ml level of cyanide without interference of sample matrix.
(2) Production of cyanide from thiocyanate
Considerable levels of cyanide (several to several decade μM) were produced from mM levels of thiocyanate in the presence of hydrogen peroxide, hydroperoxide radical and nitrite under strong acidic condition. In contrast, under the weak acidic condition production of cyanide was not significant (less than 1 μM).
(3) Production of cyanide from beverage samples
From the 50℃ incubation mixture of the commercial instant coffee drink (Nescafe Goldbrend Original, 0.15%) and nitrite (50 mM), 1.2 and 0.4 p.g/mL cyanide was produced in the presence of 10% phosphoric acid and pH 5.0 buffer, respectively. Also from those of oolong tea, 2.9 and 0.5 μg/mL cyanide was produced. Cyanide (1.7〜3.4 mg/mL) was also produced from the reaction mixture of nitrite and natural polyphenol compounds such as chlorogenic acid, caffeic acid, catechin, epicatechin, tannic acid, gallic acid and L-epinephrine. From the synthetic polyphenols, cyanide (0.5〜6.7 μg/mL, 0.1〜15 mg/mL) was also produced. The produced amount of cyanide was dependent on the substrate concentrations of nitrite and polyphenol, pH, temperature and incubation time. Production of cyanide was ascertained by the spectrophotometric method.
(4) Conclusion
Nitrite was reacted with body-fluid thiocyanate and non-nitrogenous polyphenol compounds under acidic conditions, producing significant level of cyanide in the special conditions. Forensic toxicologists should pay attention to this type of the artifactual cyanide production.
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