Authors:C. Shimasaki, T. Kanaki, S. Takeuchi, K. Hasegawa, D. Horita, E. Tsukurimichi, and T. Yoshimura
The pyrolysis of trimethylsilyl derivatives of saccharides (1) was investigated by DTA-TG, MS, GC/MS and TG-GC/MS. The DTA-TG/DTG
curves showed that the pyrolysis of 1 occurred in one stage. The exothermic peaks were due to sublimation or thermal decomposition
by vaporization. The cleavage mechanism by electron impact of 1 was classified into four categories: 1) stepwise elimination
of the side-chain, 2) cleavage of the side-chain, 3) cleavage of the pyranose ring, and 4) cleavage of the pyranose ring and
side-chain at the same time. The mass-spectrum for 1 revealed the main common four fragment ions, such asm/z 73, 191, 204 and 217, with cleavage of the pyranose ring. These fragment ions were detected with a similar retention time
in the gas cromatogram by GC/MS or TG-GC/MS. The retention time for 1 increased in the sequence aldopentose<ketohexose<aldohexose.
This result indicates that the trimethylsilyl derivatives are thermally stable. Subsequently, the pyrolysis regime for 1 obeyed
apparent 1/2-order kinetics and their apparent activation energy was estimated as 75–100 kJ/mole.
Authors:S. Ohmori, H. Tsuji, Y. Kusaka, T. Takeuchi, T. Hayashi, J. Takada, M. Koyama, H. Kozuka, M. Shinogi, A. Aoki, K. Katayama, and T. Tomiyama
With the aim of indicating environmental pollution effects by heavy metals on humans using hair, nondestructive activation
analysis was applied to 382 normal Japanese hair samples (background level). Elemental contents of hair could be determined
for Ag, Al, As, Br, Ca, Cd, Cl, Co, Cr, Cu, Fe, Hg, I, K, La, Mg, Mn, Na, S, Sb, Sc, Se, Sm, Ti, V and Zn. As these elements
in hair have wide concentration ranges, the differences in concentrations distribution between groups (sex, age, permanent
treatment and regional difference) are discussed. A method for hair sampling is presented.