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Kazuo Itoh Masahiko Chikuma Mieko Nishimura Tomoo Tanaka Motoko Tanaka Morio Nakayama Hisashi Tanaka 《Fresenius' Journal of Analytical Chemistry》1989,333(2):102-107
Summary A sulfonic acid derivative of bismuthiol-II (bisIIS) was synthesized from 4-hydrazinobenzene sulfonic acid and carbon disulfide. Selenium(IV) was adsorbed selectively and quantitatively on the anion-exchange resin loaded with bis-IIS. Selenium adsorbed on the resin was eluted by the use of penicillamine and determined by hydride generation atomic absorption spectrometry (hydride generation/AAS). Selenium(VI) and other forms of selenium, which were not adsorbed onto the resin, were collected on the resin after digestion with nitric acid followed by reduction with hydrochloric acid. Separative preconcentration of selenium(IV), selenium(VI) and other forms of selenium in 0.5 mol/l sodium chloride could be carried out successfully by the proposed procedures. However, in the case of estuarial sea water containing a large quantity of organic substances, selenium(IV) could not be separated, because organic substances interfered with the reduction of selenium(VI) to selenium(IV) by the use of hydrochloric acid. Selenium(IV) and total amount of selenium(VI) and other forms of selenium dissolved in polluted sea water samples were determined by the proposed procedures.
Bestimmung von Selen (IV) und anderen in Meereswasser gelösten Selenformen mit Hilfe eines mit dem Sulfonsäurederivat von Bismuthiol-II beladenen Anionenaustauschers und der Hydrid-AAS相似文献
915.
Hisashi Yamada Kenji Iso Makoto Saito Hirohiko Hirasawa Natalie Fellows Hisashi Masui Kenji Fujito James S. Speck Steven P. DenBaars Shuji Nakamura 《固体物理学:研究快报》2008,2(2):89-91
InGaN/GaN‐based light emitting diodes (LEDs) grown on m ‐plane, a ‐plane and off‐axis between m ‐ and a ‐plane GaN bulk substrates were investigated. A smooth surface was obtained when a ‐plane substrate was applied; however, large amounts of defects were observed. Photoluminescence measurements of the LEDs with a well thickness of 2.5 nm revealed that all the LEDs showed the peak emission wavelength at 389 nm. The PL intensity of the a ‐plane LED is one order of magnitude lower than that of the m ‐plane LED. The a ‐plane LEDs showed significant lower electroluminescence output powers than m ‐plane LEDs, suggesting that excitons are trapped by the defects, which act as non‐radiative recombination centers. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
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Yoshihiro Kitatsuji Zenko Yoshida Hiroshi Kudo Sorin Kihara 《Journal of Electroanalytical Chemistry》2002,520(1-2)
A novel electrochemical method based on controlled-potential electrolysis has been developed for the elucidation of the ion transfer at the interface between two immiscible electrolyte solutions (ITIES). A relationship between the applied interfacial potential (Eapp) and the amount of the ion transferred (Atr) was investigated after an electrolytic equilibrium was attained by controlled-potential electrolysis. The Atr was determined chemically or radiometrically instead of by current measurement. It was found that (i) controlled-potential electrolysis was applicable to the study of the transfer of such hydrophilic ions as transition metal ions which gave no appreciable current within the potential window in voltammetry or polarography at ITIES, (ii) controlled-potential electrolysis in combination with a sensitive analytical method enabled a study of the transfer reaction of an ion of very dilute concentration, and (iii) even when the transfer reaction of an ion was irreversible or quasi-reversible, a standard ion transfer potential could be determined by controlled-potential electrolysis without using a kinetic parameter. The controlled-potential electrolysis method developed was applied to the transfer reactions of actinide ions such as UO2 2+ and Am3+ from aqueous solution to nitrobenzene solution in the absence or presence of an ionophore facilitating the transfer. The Gibbs energy for the transfer of actinide ion and a stability constant of the complex between an actinide ion and the ionophore in nitrobenzene solution were determined from log D versus Eapp plots (D the ratio of the concentration of the ion in nitrobenzene solution to that in aqueous solution). The feasibility of controlled-potential electrolysis as a method for electrolytic separation of actinide ions is discussed. 相似文献