X-ray fluorescence determination of bromine in halogenated organic compounds using quasisolid emitters

A series of quasi-solid emitters is proposed for the X-ray fluorescence determination of bromine in different bromine-containing compounds. It is shown that sucrose-based glasses are the best emitters for analyzing alkali solutions of halogenated organic compounds, saccharose-based glasses and polymer films are best for analyzing powder samples, and organic gels offer most promise for analyzing liquid (at normal conditions) samples. It is noted that the proposed method can expand the possibilities of commercially produced element analyzers, which are currently intended for determining only C, H, O, N, and S in organic compounds and cannot be used for determining halogens.     

Extractional X-ray Fluorescence Determination of Small Quantities of As,Se and Hg in Aqueous Solutions

An important problem of the monitoring of the environment is control of natural and waste waters. To elaborate the X-ray fluorescence determination of arsenic,selenium and mercury in the waters we used the extraction concentration of diethyldithiocarbamate of the elements from a strong acid solution.     

1,3-Diacetylferrocene

A method is described for the preparation of 1,3-diacetylferrocene, in which ethylferrocene is first acetylated with acetyl chloride in the presence of AlCl₃ in methylene chloride to a mixture of isomeric acetylethylferrocenes. This mixture is then subjected to thin-layer chromatography, a mixture of the 1,1′- and 1,3-derivatives free from the 1,2-isomer being obtained. After oxidation of this mixture with MnO₂ to a mixture of 1,1′- and 1,3-diacetylferrocenes, the isomers are separated by preparative thin-layer chromatography.     

Synthesis of mixed bisarenechromium complexes using chromium vapor

Conclusions Cocondensation of the vapors of chromium and two aromatic compounds affords mixed bisarenechromium -complexes, benzene (benzonitrile) chromium and chlorobenzene (benzonitrile) chromium.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 9, pp. 2144–2146, September, 1982.     

Studies of phase transformations in the gelatine-water system using near-IR spectroscopy

Near-IR spectroscopy studies of gel formation mechanism are reported for gelatin-water systems. Relative absorbance in 1.4-μm and 1.9-μm bands was shown to be sensitive to the helix to coil phase transition in the pre-melting region. The formation mechanism of a metastable “coil” phase is in agreement with DSC and TGA data obtained in parallel experiments on the 10% gelatin gel. Received: 12 April 2000 Accepted: 4 October 2000     

Sampling of Natural Water Using the Ultrasonic and Ultraviolet Decomposition of Humic Substances

It was shown that the time dependences of the degree of decomposition of humic substances under exposure to ultrasound and UV radiation exhibit identical maxima. It was found that ultrasonic and ultraviolet treatments enhance the analytical signal even in the absence of humic substances. It was proposed to use the ultrasonic pretreatment before the extraction–X-ray fluorescence analysis of water to eliminate the effect of humic substances on the recovery of elements.     

Hydrogenation of a double bond in a side chain of dibenzene chromium

Russian Chemical Bulletin -