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721.
722.
Tsutomu Uryu Jun Yoshinaga Yukio Yanagisawa Masahiko Endo Junichi Takahashi 《Analytical sciences》2003,19(10):1413-1416
Laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) was used to determine the Pb/Ca ratios in the enamel of deciduous incisors, a biomarker of in utero Pb exposure, using pelletized bone certified reference materials (CRMs) as calibrants. The detection limit for Pb by LA-ICP-MS was 11 microg kg(-1) demonstrating an adequate sensitivity for Pb in the teeth of unexposed individuals (0.1-10 mg kg(-1)). The precision for the Pb/Ca ratios in NIST SRM 1486 Bone Meal was 3.4%. The correlation between Pb/Ca ratios obtained by LA-ICP-MS and those obtained by a digestion method was highly significant. We found one point calibration by a CRM was applicable for the quantification of Pb in tooth enamel. This method will be valuable for the assessment of in utero Pb exposure levels. 相似文献
723.
Halide ions could be visualized via fluorescence quenching in microcolumn ion chromatography. The fluorescence of quinine sulfate, which was contained in an acidic eluent, was quenched by halide ions. The observed fluorescence quenching values increased in this order: iodide, bromide, and chloride. The present detection system was relatively sensitive to halide ions except for fluoride: other anions gave smaller signals than halide ions. The present detection system provided quantitative information, so it could be applied to the determination of chloride in water samples. 相似文献
724.
The sedimentation and drying dissipative structural patterns were formed during the course of drying binary mixtures among
colloidal silica spheres of 183 nm, 305 nm, and 1.205 μm in diameter in aqueous suspension on a watch glass, a glass dish,
and a cover glass, respectively. The broad ring-like sedimentation patterns were formed within several hours in suspension
state for all the substrates used. Colorful macroscopic broad ring-like drying patterns were formed for the three substrates.
In a watch glass, macroscopic drying patterns were composed of the outer and inner layers of small and large spheres, respectively.
The two colored layers were ascribed to the Bragg diffractions of light by the dried colloidal crystals of the corresponding
spheres. The width ratio of the layers changed in proportion to the mixing ratio of each spheres. In a glass dish, wave-like
macroscopic drying patterns were observed in the intermediate areas between the outside edges of the broad ring and the inner
wall of the cell. On a cover glass, the sphere mixing ratios were analyzed from the widths of the drying broad rings of the
small spheres at the outside edge. High and distinct broad rings of small spheres and the low and vague broad one formed at
the outer edges and in the inner area, respectively. Drying dissipative pattern was clarified to be one of the novel analysis
techniques of colloidal size in binary colloidal mixtures. 相似文献
725.
Matsuo T Asano A Ando T Hisaeda Y Hayashi T 《Chemical communications (Cambridge, England)》2008,(31):3684-3686
A reconstituted myoglobin with a synthetic cofactor having anionic binding sites effectively works as a photocatalyst for hydrogen generation in the presence of monomethylated bipyridinium. 相似文献
726.
Actin-binding marine macrolides exhibit significant structural and functional diversity. In this issue, Perrins et al. demonstrate that a long stereochemically conserved aliphatic side chain, known as the "tail", found in many of these compounds is the functional determinant of cytotoxicity (Perrins et al., 2008). 相似文献
727.
728.
Ohne Zusammenfassung 相似文献
729.
730.
Takaharu Asano Pi-Chao Wang Akio Iwasaki 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2010,75(1):305-309
For the purpose of detection of multimetal components in environment, alteration of the spectrophotometrical metal sensitivity of porphyrin was attempted. Two porphyrin-incorporated polymers were newly synthesized by the free radical copolymerization of protoporphyrin IX disodium salt and vinyl monomers, and their metal sensitivities were examined by measuring the difference absorption spectra. These porphyrin-incorporated polymers showed different metal sensitivities and their sensitivities were altered by change of pH. Three measuring reagents, which were different in the combination of the porphyrin-incorporated polymers and pH, were used for the simultaneous detection of multimetal components in metal ion mixtures. The difference spectra of these reagents showed the separate peaks corresponding to six metal ions, Bi(III), Co(II), Cu(II), Mn(II), Pb(II), and Zn(II). The spectra were acquired reproducibly by using standard normal variate (SNV) transformation. Furthermore, this method was applied to detect multimetal components in water samples such as tap water and industrial effluent. 相似文献