The retention regularities on a column packed with microspherical zeolite 13X particles were studied for different classes of compounds (alkanes, aromatic substances, oxygen-, nitrogen-, chlorine-, and sulfur- containing compounds) under conditions of hydrophilic interaction liquid chromatography (HILIC) using methanol and acetonitrile as mobile phases. In general, the retention (logk') of studied substances having kinetic diameter less than zeolite pore size is proportional to their polarity. The retention of organic substances was compared for 13X and mesoporous silica columns. A special attention was paid to the retention of n- and iso-alcohols homologues, for which a electrostatically induced sieving effect was observed. It was found that retention factors (k') of solutes on 13X depend strongly on flow rate of the mobile phases indicating the presence of kinetic selectivity effect for the micrporous adsorbent. For the first time the baseline separation was obtained for the low homologues of n-alkanols. Also, selective separation of methanol and methanol-d4 (selectivity alpha = 1.274; resolution of peaks RS = 1.32) is achieved on 50 x 4.6 mm I.D. column with acetonitrile as the eluent.

Inorganic zeolites or microporous crystalline aluminosilicates have high porosity, developed specific surface area, uniform pore size and ion exchange properties, which determines their molecular sieve and adsorption properties. The use of zeolites as catalysts, dryers of solvents and gases, and selective sorbents for the separation of low molecular weight compounds is widely known. Zeolites are widely used as fillers for chromatographic columns in gas adsorption chromatography. Little is known about the use of zeolites in high-performance liquid chromatography (HPLC) and the mechanism of sorbate retention on these sorbents. Depending on the properties of sorbates, retention is determined by a combination of ion exchange, adsorption, molecular sieve effect, as well as kinetic selectivity. Due to solvation of the sorbent surface in HPLC, the thermodynamic parameters of the interaction of sorbates with zeolite change, the effective pore size decreases, and the diffusion of separated compounds into the pores of the sorbent becomes more difficult. Nevertheless, zeolites are promising adsorbents, since specific size (dpore) and the pore geometry of zeolites, as well as the possibility of selecting zeolites with a certain polarity, determines the high selectivity of the separation of low molecular weight compounds. Wide-pore zeolites with dpore (0.6-0.8 nm) with 8, 10, 12, and 14-membered ring channels are of greatest interest for HPLC. This review provides brief information about the classification, composition, structure of zeolites and their effect on their adsorption properties, as well as systematizes data on the use of zeolites in HPLC.

Luminescence spectra of several polarity indicators, including Coumarin 153 and coronene that were previously studied at room temperature and Nile Red and Pigment Red 179, were recorded at 20 and 120°C in solutions of liquid stationary phases of various polarities. The effect of temperature on the spectral parameters sensitive to the stationary phase polarity was estimated for these indicators. The prospects for estimating the polarity of stationary liquid phases using luminescent methods at high temperatures was demonstrated.

The estimation of the applicability and the choice of the scale of quantitative one-parameter evaluation of the polarity of stationary liquid phases were carried out for gas-liquid chromatography. The absorption and luminescence spectra of five indicators including coumarin 153, coumarin 314, coronene, 4-dicyanomethylene-2-methyl-6-[4-(di-methylamino)-styryl]-4H-pyran (DCM), 3-aminophthalimide have been obtainned in solvents of different polarity at room temperature. The dependence of the wavelength of the fluorescence and absorption maxima on the polarity of the medium was evaluated. Various spectroscopic polarity scales are compared. The fluorescent coronene scale has been shown to be the most appropriate. This scale was used to assess the polarity of some widespread phases (squalane, polydimethylsiloxane liquid PMS-100, 3,3'-oxydipropionitrile, 2-ethyl-hexylsebacinate, etc.) for gas-liquid chromatography. This approach has been shown to be promising for preliminary selection of chromatographic stationary phases.

The applicability of stationary liquid phases for gas–liquid chromatography was evaluated. The scale for quantitative one-parameter estimation of their polarity was chosen. Absorption and luminescence spectra of the five indicators coumarin 153, coumarin 314, coronene, 4-dicyanomethylene-2-methyl-6-[4-(dimethylamino)styryl]-4H-pyran (DCM), and 3-aminophthalimide in solvents of different polarity were obtained at room temperature. The dependence of the fluorescence and absorption maxima wavelengths on the medium polarity was evaluated. Various spectroscopic polarity scales were compared to show that the coronene fluorescence scale was most appropriate. This scale was used to assess the polarity of some widespread phases (squalane, polydimethylsiloxane PMS-100, 3,3′-oxydipropionitrile, 2-ethylhexylsebacate, etc.) for gas-liquid chromatography. This approach was shown to be promising for preliminary selection of chromatographic stationary phases.

New composite adsorbents including silica supports (silica, aerosilogel, and diatomite) and carbon materials (multiwall carbon nanotubes and pyrolytic carbon) have been prepared and characterized. The analytical capabilities of the produced sorbents have been evaluated by their efficiency in the express pre-concentration of volatile organic compounds (butanol and phenols) from the air stream. The prepared surface-layered adsorbents containing multiwall carbon nanotubes placed onto the surface of aerosilogel by use of the carbon vapor deposition method with preloading cobalt nanostructures as a catalyst were found significantly more efficient than traditionally used graphitic carbon-based adsorbents Carbopacks B, C, and X. Additionally, a new adsorbent composed of diatomite Porochrome-3 support coated with a pyrocarbon layer was prepared. This low surface area composited adsorbent allowed both quantitative pre-concentration of phenol and isomeric cresols from the air and their thermal desorption. The developed adsorbents provided fast pre-concentration of selected phenols with a concentration factor of 2 × 103 in 5 min and were used for gas chromatographic determination of analytes in the air at low concentration levels starting from several μg/m3 with a flame ionization detector.

The migration and accompanying adsorption of the synthetic anionic food dyes Yellow Sunset FCF (E110) and Green Fast FCF (E143) in a fused silica capillary are studied by capillary zone electrophoresis. The adsorption of dyes is quantitatively estimated from the dependence of electrophoretic mobility μ ep on the dye concentration in a sample. We find that the electrophoretic mobility of E143 dye reaches a maximum at a low concentration, and that of the E110 dye reaches a maximum at an even lower concentration because the E143 molecule is larger and more hydrophilic. The dependence of μ ep on the concentration of Green Fast FCF in a sample is compared with the isotherm of adsorption of this dye on Silokhrom S-80 silica gel. The maximum adsorption capacity of silica gel for E143 is 6 × 10 –4 μM/m 2 .

The comparative study of adsorption properties of several adsorbents with focus on selective isolation of water-soluble B vitamins (B 2 , B, B 6 and B 12 ) from food products and some pharmaceutical formulations by solid-phase extraction is performed. The adsorption of vitamins was investigated for eleven adsorbents including bare silica, silica modified with polyvinylpyrrolidone, octadecyl-, aminopropyl-, cyanobutyl-functional groups, poly(styrene–divinylbenzene) modified with lactam groups, hypercrosslinked polystyrene, activated carbon and porous microdispersed sintered detonation nanodiamond. Dynamic adsorption capacities of adsorbents for each of the tested vitamins were determined from the dynamic output curves. The highest adsorption capacity was found for HCPS-based sorbents, but complete desorption from these sorbents required harsh conditions. On this reason MSDN was suited better for the preconcentration of water soluble vitamins.

28 ноября 2018 исполнилось 110 лет со дня рождения Андрея Владимировича Киселева, выдающегося физико-химика, заслуженного деятеля науки и техники РСФСР, профессора МГУ им. М.В. Ломоносова. Андрей Владимирович Киселев родился 28 ноября 1908 г. в Москве. В 1930 г. он закончил МВТУ им. Баумана. На втором курсе он начал заниматься научной работой под руководством профессора Н.А. Шилова, в 1933 г. вышла его первая научная статья. В 1939 г. А.В. Киселев защитил кандидатскую диссертацию, а в 1943 г. начал преподавать на химическом факультете МГУ. С 1946 по 1984 гг. он возглавлял лабораторию адсорбции и хроматографии химического факультета, в 1965 г. стал заведующим лаборатории химии поверхности ИФХ. В 1950 г. А.В. Киселев защитил докторскую диссертацию. А.В. Киселев работал над фундаментальными проблемами химии поверхности, адсорбции и хроматографии. Одним из первых он начал комплексные исследования адсорбционных явлений химическими, калориметрическими и спектроскопическими методами. В статье представлен список его приоритетных работ. А.В. Киселева хорошо знали во всем мире, его лаборатория по адсорбции и хроматографии в МГУ стала международным исследовательским центром. Там работали аспиранты и стажеры, представители пяти континентов. Приоритетные работы А.В.Киселева продолжают использоваться и развиваться и в настоящее время: применение молекулярно – статистических расчетов, принципов спектроскопии (работы Буряка А.К., Матюшина Д.Д., Лыгина С.Н.),методов гидротермичной обработки адсорбентов, химического модифицирования силикагелей. Широко применяются поверхностно-пористые сорбенты в ВЭЖХ, графитированные термические сажи, карбосита, карбохромы как для концентрирования, так и для разделения. Профессор Андрей Владимирович Киселев останется в памяти людей как человек неутомимой жажды познания, огромногочувства ответственности, создавший большую научную школу и оставивший после себя научные труды, монографии и учебники для новых поколений исследователей.

В статье дан исторический аспект появления первых теорий адсорбции в 20 веке: с однойстороны, потенциальных теорий А.Т. Эйкена и М. Полани (1914), а с другой стороны –мономолекулярной теории И. Ленгмюра (1916-1918). Продемонстрированы основные положения этихтеорий в аналитическом контексте.

В статье описана история развития представлений об адсорбции по работам ученых конца 18 и 19 века. Приведены первые теоретические интерпретации (флогистическая, механическая (физическая), химическая) явления адсорбции на границах газ - твердое тело и жидкость – твердое тело.

Исследована адсорбция ряда соединений, обладающих свойствами кислот, оснований и амфотерных соединений, на пористом микродисперсном детонационном наноалмазе (ПМДН) из водных растворов. Из анализа результатов адсорбции кислотных и основных красителей на поверхности ПМДН следует, что на поверхности сорбента имеются как основные, так и кислотные группы, с которыми способны вступать во взаимодействия молекулы органических кислот, оснований и амфотерных соединений. Обработка исходного образца кислотой или основанием приводит к уменьшению адсорбции кислотных и основных красителей, что может быть связано с удалением примесей с поверхности ПМДН, с которыми способны взаимодействовать кислотные и основные соединения.

Adsorption of water-soluble vitamins, including riboflavin (В2), nicotinamide (PP, B3), pyridoxine (B6), cyanocobalamine (В12) from water-organic solutions on microdispersed sintered detonation nanodiamond (MSDN), modified in different ways, was studied using high-performance liquid chromatography (HPLC). The effect of composition (from 5% to 80 v/v % of CH3CN) and рН (рН 2.7/6.0) of mobile phase, as well as temperature of chromatographic column (tc = 45/65 °C) on vitamins adsorption was studied. Nonlinear dependences of the sorbate retention factors on the acetonitrile content in the mobile phase are found out, indicating the variation of specific and non-specific interactions of vitamins with MSDN surface. Based on the obtained results, the conditions for chromatographic separation of the mixture of water-soluble vitamins in isocratic mode of HPLC on MSDN are optimized.

Using X-ray diffractometry, scanning electron microscopy, thermography, elemental analysis, and others have studied the properties of a number of ores rich in iron, copper and other metals. In a number of investigated samples, significant amounts of magnesium ferrite have been found, which can be used as catalysts in the reactions for the production of valuable monomers such as butadiene, styrene, isoprene, etc. and also in the dehydrogenation reactions of many hydrocarbons. The possibility of its extraction magnesium ferrite from the natural sample "Hematite-Magnetite" was studied

With the methods of X-ray difrractometry, scanning electron microscopy, thermograhy, element analysis and others have investigated the white sludge, formed in the production of alumina from bauxites and alunites in the Ganja Alumina Combine. The possibility of synthesis of sorbents from it for dehydrating trasnsformer oil from trace amounts of moisture has been studied; catalyzers used in petrochemical processes; as well as in building materials without the addition quartz sand to the composition of white sludge

The effect the surface chemistry of ultradispersed diamond (UDD) has on the adsorption of watersoluble dyes is considered. A comparison is made to adsorption on graphitized thermal carbon black (GTCB), which has a homogeneous and nonporous surface. The adsorption isotherms of dyes and the dependence of the adsorption on the pH of solutions are measured. It is found that UDD adsorbs acid (anionic) dyes—acid orange (AO) and acid anthraquinone blue (AAB)—but barely adsorbs a basic (cationic) dye, methylene blue (MB), because of the predominance of positively charged basic groups on the surface of UDD. The maximum adsorption of AO is much lower on UDD than on GTCB, while the maximum adsorption of AAB is similar for both surfaces. The adsorption of AO on UDD depends strongly on the pH of the solution, while the adsorption of AAB is independent of this parameter. It is suggested that the adsorption of AAB is determined not only by ionic and hydrophobic interactions but also by coordination interactions with impurity metal ions on a UDD surface. It is concluded that the adsorption of dyes characterizes the chemistry of a UDD surface with high sensitivity.

The adsorption properties of sulfated aluminum oxide (9% SO 4 2- /γ-Al2O3) and a cobalt-containing composite (0.5%Сo/SO 4 2- /γ-Al2O3) based on it are studied via dynamic sorption. The adsorption isotherms of such test adsorbates as n-hydrocarbons (C6–C8), benzene, ethylbenzene, chloroform, and diethyl ether are measured, and their isosteric heats of adsorption are calculated. It is shown that the surface sulfation of aluminum oxide substantially improves its electron-accepting properties, and so the catalytic activity of SO 4 2- /γ-Al2O3 in the liquid-phase alkylation of benzene with octene-1 at temperatures of 25–120°C is one order of magnitude higher than for the initial aluminum oxide. It is established that additional modification of sulfated aluminum oxide with cobalt ions increases the activity of this catalyst by 2–4 times. It is shown that adsorption sites capable of strong specific adsorption with both donating (aromatics, diethyl ether chemosorption) and accepting molecules (chloroform) form on the surface of sulfated γ-Al2O3 promoted by cobalt salt.

Adsorption properties of γ-Al2O3 modified with Co (5 and 10 wt %) and Co (5 wt %) species are investigated by dynamic adsorption. N-hexane, n-heptane, n-octane, benzene, toluene, ethylbenzene, chloroform, and diethyl ether were used as test adsorbates. Adsorption isotherms were measured, and isosteric adsorption heats were calculated for the indicated sorbates. It was shown that the adsorption isotherms of all the adsorbates and at all the temperatures of measurements on γ-Al2O3 modified with Co (5 wt %) and CoO (5 wt %) nanoparticles located above that recorded for the initial γ-Al2O3 sample. It was established that the surface of modified γ-Al2O3 possessed mainly electron-accepting properties. The 5% Со/γ-Al2O3 and 5% СоO/γ-Al2O3 nanocomposites exhibited the greatest adsorption capacity relative to aromatic hydrocarbons.