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1-Nitro-4-benzothiazolylsulfanyl-and -sulfonyldienes were synthesized. The former were obtained by thiylation of 1,4-dinitrodienes, and the latter were prepared from the former by oxidation with hydrogen peroxide. The spatial structure of compounds obtained was considered.

Electrodes modified with poly(arylene phthalide ketones) were developed for the voltammetric determination of isomers of aromatic nitro compounds. A polynomial algorithm for processing analytical signals from a sensor array was tested in the analysis of ternary mixtures. It is shown that the sensor array offers promise for analyzing multicomponent mixtures in the case when analytical signals overlap.

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Abstract-The paper describes solving the problem of direct silicon determination at low levels in uranium materials, caused by the spectral interferences of polyatomic ions and the high value of blank levels, using inductively coupled plasma mass spectrometry (ICP MS). To overcome the interference problem, two pri mary techniques have been applied: double focusing high resolution ICP MS and dynamic reaction cell (DRC) filled with highly reactive ammonia gas. All measurements were performed at high resolution (m/Δm = 4000) on an Element 2 mass spectrometer and pressurized mode of a dynamic reaction cell on an Elan DRC II mass spectrometer. The ways to reducing background levels are investigated. The effects of oper ating conditions, such as plasma parameters, DRC system original parameters, and uranium matrix influence on the analytical signals of silicon at m/z = 28 have been observed for different mass spectrometer types. The detection limits and the random error characteristics (relative standard deviation) of silicon determination in uranium materials were estimated.

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