Volume 72, Nº 1 (2017)

The structure of 9-(5,5-dimethyl-2,4,5,6-tetrahydro-1H-phenalen-2-yl)-5,5,9-trimethyl-5,6,8,9-tetrahydrocyclopenta[а]phenalen-10(4H)-one was determined by X-ray crystallography. The intermolecular interaction energies were calculated by the atom-atomic approach for the crystal structure. The character of the crystal structure and the structural subclass were established.

A method is proposed for determination of lanthanum, cerium, praseodymium, neodymium, and samarium in mineral water by means of total-reflection X-ray fluorescence analysis. In this work, the combined technique of preconcentration of rare earth ions is used. This technique consists of coprecipitation of metal hydroxides on the collector (iron (III) hydroxide) and dispersive liquid–liquid microextraction of their complexes with 1-(2-pyridylazo)-2-naphthol by chloroform in the presence of ethanol. The use of the developed hybrid approach allows simultaneous determination of the mentioned metals in mineral water in the range n(10^–2–10¹) μg/L. The results of analysis of Arkhyz and Rychal-Su mineral waters by the proposed extraction–X-ray fluorescent method are confirmed by the literature data, obtained by inductively coupled plasma mass spectrometry.

The specular and diffuse reflectance spectra of organic matrices on the basis of photonic crystals formed of polystyrene microspheres with a particle size of 230 nm and polydimethylsiloxane layers, which are both applied on substrates made of quartz glass and acrylic plates, are recorded. Part of the organic matrix changes color from green to red-yellow 2 to 5 min after contact with a nonpolar solvent. The kinetics of structural changes occurring in the organic matrix under the influence of non-polar organic solvents, such as toluene, benzene, and n-hexane, is studied by diffusion reflectance spectroscopy. The equilibria in the organic matrix are achieved in 15–20 min.

Sonocatalytic oxidative desulfurization of oil from the Zhanazhol oilfield was investigated. Application of stepwise periodic treatment in an ultrasound field in the presence of a Ni-skeletal catalyst and oxidizer was shown to be an effective procedure for improving the quality of oil and oil-based products, which allowed targeted change of its chemical composition, increasing the yield of light products (gasoline and diesel fractions from 15.6 to 21.9 and from 47.7 to 58.6 wt %, respectively) and decreasing the sulfur content in oil products to 49%.

Cerasome-forming amphiphile based on L-aspartic acid dihexadecyl ester derivative with (3-aminopropyl) triethoxysilane moiety in its structure was synthesized. Mixed storage-stable lipid dispersions containing phosphatidylcholine were prepared and their properties were examined.

An X-ray fluorescence analysis technique is proposed, which is based on using ratios of intensities of spectral lines. The technique includes performing calculations for evaluation of calibration equations, which allows using few reference samples or carrying out standardless analysis, if necessary. That parameters of the calibration equations depend linearly on concentrations of disturbing elements allows one to simplify taking their influence into account. To apply the developed technique to analysis of samples containing a significant amount of undetectable light elements, a use of a dependence of intensity ratio of the characteristic radiation of the X-ray tube’s anode, coherently and incoherently scattered by a sample, on a total content of undetectable elements is proposed. The technique’s adequacy is demonstrated by analysis of standard steel samples, metal cuttings and iron-ore materials.

The possibility of determining the kerosene content in the ground using a flash detector with open cell detection based on a piezosensor is considered. The coating of the electrodes of a quartz crystal resonator and its weight for the detection of kerosene vapors in a wide concentration range, the structural parameters of the flash detector housing, the conditions for detecting kerosene vapors above ground are optimized. The accuracy and reliability of assessing of the level of kerosene contamination in different types of soils are estimated in field conditions.