An original method is proposed for the preparation of water samples by solid-phase microextraction (SPME) to the determination of hydrocarbon impurities. Substances are eluted with a microamount of an extractant (5 μL per 2 mg of adsorbent) using a centrifuge. Special cartridges are developed for centrifuging. Porapak Q and Tenax TA adsorbents are studied; an optimum solvent is chosen for each adsorbent. The use of SPME with a centrifuge ensures the determination of hydrocarbon impurities in water at the level down to ∼0.3 μg/L.

Предложен оригинальный метод твердофазной микроэкстракции углеводородов из воды с применением центрифуги. Приведены сравнительные результаты хроматографического элюирования веществ после жидкофазной и твердофазной микроэкстракции. Рассчитаны процентное извлечение веществ из водного раствора и минимальный предел обнаружения для ароматических и алифатических соединений.

The effect of an extractant on the yield of lipids depending on the moisture content of peat was studied. A maximum yield of lipids was obtained upon extraction with a mixture of methyl tert -butyl ether and ethanol in a ratio of 1: 1. It was found that the use of an ethyl acetate-ethanol or methyl tert -butyl ether-ethanol solvent mixture led to a decrease in the acid and peroxide numbers of lipids regardless of the moisture content of peat. The antioxidant activity of lipids increased with the moisture content of peat.

The silver magnesium zirconium molybdate Ag4Mg2Zr(MoO4), undoped and aliovalently doped with yttrium and aluminum, has been characterized by impedance spectroscopy, X-ray diffraction, and IR spectroscopy. The materials studied possess relatively high ionic conductivity at temperatures above 550 K. Partial yttrium substitution on the zirconium site ensures an increase in ionic conductivity almost throughout the temperature range studied.

The interaction between polychlorobiphenyls (PCBs) and an alkaline amino acid reagent (NaL) in solutions and a gray forest soil contaminated by these solutions was studied by IR spectroscopy and gas-liquid chromatography depending on the component concentrations and reaction time. Intermolecular interaction of PCBs with NaL by hydrogen bonds of hydroxyl, amide, and carboxyl groups, as well as the detachment of chlorine from the aromatic ring of PCB molecules, was revealed in solutions. A significant decrease (by 32 to 75%) in total PCBs was observed in solutions and gray forest soil in the presence of the amino acid reagent depending on the concentration of the reagent and the amount of its addition to soil samples. Changes in the relative content of low-and high-chlorinated PCB congeners were revealed in solutions and PCB-contaminated gray forest soil in the presence of the amino acid reagent, which indicated their stepwise dechlorination.

Conduction properties and intermolecular interactions in systems based on high-molecular-weight sulfonic acids (poly(4-styrenesulfonic), poly(2-acrylamidomethylpropane-sulfonic), and perfluorosulfonic (MF-4SC)) and polyaniline were studied by impedance and IR spectroscopy. In all systems, an interpolyelectrolyte complex is formed due to strong hydrogen bonding. In two former cases, the interpolyelectrolyte complexes form nanodispersed powders with ionic and electronic conductivity. MF-4SC—polyaniline solutions were used for the membranes preparation with high ionic conductivity.

Phase transitions and cation mobility in double molybdates K 2 M 2 II (MoO 4 ) 3 with M = Mg or Co and the products of their heterovalent doping with scandium(III) and vanadium(V) have been studied. The transition from low to high conductivity in K 2 M 2 II (MoO 4 ) 3 is the result of a two-stage phase transition, whose occurrence is significantly extended in time. Heterovalent substitutions noticeably decrease the heat of the phase transition. The transition to the low-temperature phase is not achieved even after long-term exposure.

Potassium magnesium and potassium cobalt molybdates of composition K 2 M 2 II (MoO 4 ) 3 (M = Mg, Co) and the products of their heterovalent doping by scandium(III) and vanadium(V) ions have been studied by impedance spectroscopy, powder X-ray diffraction, and electron microscopy. The compounds have high ion conductivity. Partial heterovalent substitutions of scandium for magnesium or vanadium for molybdenum additionally increases ion conductivity. The high conductivity of potassium magnesium and potassium cobalt molybdates allows us to consider them as promising solid electrolytes with potassium conductivity.

Impedance spectroscopy, X-ray powder diffraction, and electron microscopy are used to study silver magnesium and silver cobalt molybdates of composition Ag2A 2 II (MoO4)3 (A = Mg, Co) and the products of their aliovalent doping by scandium(III) and vanadium(V). The double molybdates have high ionic conductivities at temperatures above 600 K. A partial aliovalent substitution of scandium for magnesium or vanadium for molybdenum increases the ionic conductivity of the molybdates below 473 K. The defect mobility and the enthalpy of defect formation in the Ag2Mg2(MoO4)3 structure are estimated proceeding from the experimental data.

Model experiments were performed for studying the effect of different concentrations (2 and 20 mg/kg) of polychlorinated biphenyls (PCBs) on the physical properties of natural materials (samples from the A horizon of loamy gray forest soil, river sand, and mantle loam). It was found that PCBs affect the aggregation of micro-and macroparticles in samples from the A horizon of gray forest soil and loam and the reflective properties of sand. It was also found that the coefficient of filtration in the substrates studied varies under the effect of PCBs. The rate of the water rising in the loam samples in the presence of PCBs decreases by 5.9 times for particles <3 mm and remains constant for particles <0.25 mm; in the samples from the A horizon of gray forest soil, the rate of the water rising increases by a factor of 1.3–1.9 for particles of all sizes. The water-retaining capacity of loam and gray forest soil from the A horizon decreases in the presence of PCBs.

Data on the contents of polychlorinated biphenyls (strong toxicants) in soils of the town of Serpukhov (Moscow oblast) are presented. The patterns of their distribution in soil profiles of different urban areas are found. Temporal changes in the polychlorinated biphenyl concentrations are revealed. Further special investigations into the behavior of these pollutants and elaboration of methods for their detoxication are needed.