Key words: supercritical extraction, wild carrots, HCMS, ecology, sterols, fatty acids
To study the influence of ecological growing conditions on the chemical composition of plants, supercritical carbon dioxide extraction of wild carrot samples, widespread in all regions of the world with a temperate climate (Daucus carota subsp. maritimus). Using the methods of gas-liquid chromatography and mass spectral analysis, volatile organic compounds, fatty acids and phytosterols in the studied objects were determined in the extracts obtained. The dependence of the chemical composition of wild carrots on its growing conditions (temperature, precipitation, solar radiation, etc.) is shown.
doi:10.34984/SCFTP.2023.18.3.001
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ГОСТ
7.0.100-2018
Relationship of component composition of supercritical СО<sub>2</sub> extracts of wild carrots with growing conditions / – Текст : непосредственный // Сверхкритические Флюиды: Теория и Практика.. – 2023. – Т. 18. – № 3. – С. 3-14. - DOI: 10.34984/SCFTP.2023.18.3.001
TRANSLIT
Zavisimost komponentnogo sostava sverhkriticheskogo SO<sub>2</sub>-ekstrakta morkovi dikoj ot uslovij proizrastaniya / – Tekst : neposredstvennyj // Sverhkriticheskie Flyuidy: Teoriya i Praktika.. – 2023. – Т. 18. – № 3. – S. 3-14. - DOI: 10.34984/SCFTP.2023.18.3.001
En
Relationship of component composition of supercritical СО<sub>2</sub> extracts of wild carrots with growing conditions. Sverhkriticheskie Flyuidy: Teoriya i Praktika, 3, 3-14 (2023). https://doi.org/10.34984/SCFTP.2023.18.3.001
Key words: svinec, okislenie, vodokislorodnyj flyuid, peroksid vodoroda
The paper presents the research results of the oxidation of bulk lead samples with oxygen, water vapor, water-oxygen mixture, and hydrogen peroxide solution during heating of the reactor at a rate of 1 K/min up to 873 K under the conditions of high reactant density (ρН2О ≤ 4,58 и ρO2 ≤ 0,58 моль/дм3). The smallest gain in the weight of the samples was detected during the oxidation of lead with water vapor and oxygen, and the largest one, with the H2O/O2 mixture. It follows from the time dependences of the temperature and pressure of the reaction mixture that oxidation of lead by the H2O/O2 mixture noticeably accelerates at T > 425 K. An increase in the O2 content in the mixture and a decrease in the water vapor density intensify the oxidation. According to the X-ray diffraction analysis data, Pb3O4 (minium) predominates in the composition of lead oxidation products formed in the H2O/O2 mixture. It has been revealed that the size and morphology of oxidized lead particles depend on the composition of the reaction mixture. The mechanisms of lead oxidation are discussed.
doi:10.34984/SCFTP.2023.18.3.002
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ГОСТ
7.0.100-2018
Peculiarities of bulk lead sample oxidation in water-oxygen fluid / – Текст : непосредственный // Сверхкритические Флюиды: Теория и Практика.. – 2023. – Т. 18. – № 3. – С. 15-28. - DOI: 10.34984/SCFTP.2023.18.3.002
TRANSLIT
Osobennosti okisleniya massivnyh obrazcov svinca v vodokislorodnom flyuide / – Tekst : neposredstvennyj // Sverhkriticheskie Flyuidy: Teoriya i Praktika.. – 2023. – Т. 18. – № 3. – S. 15-28. - DOI: 10.34984/SCFTP.2023.18.3.002
En
Peculiarities of bulk lead sample oxidation in water-oxygen fluid. Sverhkriticheskie Flyuidy: Teoriya i Praktika, 3, 15-28 (2023). https://doi.org/10.34984/SCFTP.2023.18.3.002
Key words: laminariya japanese Saccharina japonica, iodine, alginic acid, subcritical water, extraction, functional nutrition.
Within the framework of this work, the efficiency of extracting iodine and alginic acids from dry thalli of laminariya japanese (Saccharina japonica) with subcritical water at temperatures of 130, 150 and 170°C in the dynamic extraction mode was evaluated. It has been established that during extraction, iodine is completely extracted from the thallus of laminariya japanese, however, in the dynamic extraction mode, only about 45 % of iodine-containing compounds pass into the extract, the rest remains in the mucus that forms around the particles of laminariya during the extraction process. The obtained extracts of laminariya japanese contain fatty and phenolic acids, alcohols, carbohydrates. Marmalade, made on the basis of a subcritical water extract of kelp weighing about 6 g, contains about 20 daily doses of iodine, can be used as a functional food product.
doi:10.34984/SCFTP.2023.18.3.003
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ГОСТ
7.0.100-2018
Subcritical water extracts of laminariya japanese as a potential basis for functional nutrition / – Текст : непосредственный // Сверхкритические Флюиды: Теория и Практика.. – 2023. – Т. 18. – № 3. – С. 29-38. - DOI: 10.34984/SCFTP.2023.18.3.003
TRANSLIT
Subkriticheskie vodnye ekstrakty laminarii yaponskoj kak potencialnaya osnova funkcional'nogo pitaniya / – Tekst : neposredstvennyj // Sverhkriticheskie Flyuidy: Teoriya i Praktika.. – 2023. – Т. 18. – № 3. – S. 29-38. - DOI: 10.34984/SCFTP.2023.18.3.003
En
Subcritical water extracts of laminariya japanese as a potential basis for functional nutrition. Sverhkriticheskie Flyuidy: Teoriya i Praktika, 3, 29-38 (2023). https://doi.org/10.34984/SCFTP.2023.18.3.003
Key words: supercritical antisolvent precipitation, morphology, crystallization, phase equilibria
The effect of pressure on the size and morphology of levofloxacin hydrochloride particles precipitated by supercritical antisolvent precipitation (SAS) was investigated. It is shown that the crystallization of levofloxacin from the two-phase CO2—dimethylforamide—levofloxacin hydrochloride system leads to the production of particles with a bimodal size distribution. Crystallization from a single-phase system leads to a change in the mixing mode of CO2 and solution, and as a result, preci pitation of particles with a monomodal size distribution is observed. Liquid—gas equilibrium curves were obtained for the CO2— dimethylforamide—levofloxacin hydrochloride system at a temperature of 40°C.
doi:10.34984/SCFTP.2023.18.3.004
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ГОСТ
7.0.100-2018
Supercritical antisolvent precipitation of levofloxacin hydrochloride from single-phase and two-phase mixtures of CO<sub>2</sub>—dimethylformamide / – Текст : непосредственный // Сверхкритические Флюиды: Теория и Практика.. – 2023. – Т. 18. – № 3. – С. 39-50. - DOI: 10.34984/SCFTP.2023.18.3.004
TRANSLIT
Sverhkriticheskoe antisolventnoe osazhdenie gidrohlorida levofloksacina iz odnofaznoj i dvuhfaznoj smesej SO<sub>2</sub>—dimetilformamid / – Tekst : neposredstvennyj // Sverhkriticheskie Flyuidy: Teoriya i Praktika.. – 2023. – Т. 18. – № 3. – S. 39-50. - DOI: 10.34984/SCFTP.2023.18.3.004
En
Supercritical antisolvent precipitation of levofloxacin hydrochloride from single-phase and two-phase mixtures of CO<sub>2</sub>—dimethylformamide. Sverhkriticheskie Flyuidy: Teoriya i Praktika, 3, 39-50 (2023). https://doi.org/10.34984/SCFTP.2023.18.3.004
Key words: mixed La—Al-oxides, lanthanum aluminate, lanthanum oxide, structure, water fluid, catalysts, stability, oxidative coupling of methane
The catalytic properties in the oxidative coupling of methane (OCM) and the structural features of a series of mixed lanthanum-aluminum oxides with a constant atomic ratio La : Al = 1 : 1 were studied. The samples were prepared from precursors containing La and Al nitrates and organic component — filter paper or starch. After drying and burning the organic component, the samples were subjected to additional heat treatment and exposure to water fluid (WF) with a density of 0.2 g cm-3 at 415 °C. After calcination at 900°C, all the samples contain a phase of lanthanum aluminate LaAlO3 with a cubic perovskite structure. Varying the type of organic component, as well as the sequence of procedures and processing conditions leads to the production of samples with different morphologies and catalytic properties. The minimum activity, selectivity for OCM products and stability over time is demonstrated by the sample obtained under conditions conducive to the formation of the most ordered structure — successively calcined at 900 °C, treated in a WF medium and re-calcined at 900 °C. The most efficient and stable turned out to be the sample whose crystal structure was formed mainly in the WF medium. It was noted that there is no correlation between the morphology of particles and the specific surface area of the samples, on the one hand, and their catalytic properties, on the other. It was assumed that the catalytic properties are determined by the type and number of point defects in the crystal structure — primarily cation vacancies and, as a consequence, hole centers of the [O–] type in the anion sublattice.
doi:10.34984/SCFTP.2023.18.3.005
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ГОСТ
7.0.100-2018
Structural features of mixed La—Al-oxides and stability of their catalytic properties in oxidative coupling of methane / – Текст : непосредственный // Сверхкритические Флюиды: Теория и Практика.. – 2023. – Т. 18. – № 3. – С. 51-68. - DOI: 10.34984/SCFTP.2023.18.3.005
TRANSLIT
Strukturnye osobennosti smeshennyh La-Al-oksidov i stabil'nost ih kataliticheskih svojstv v processe okislitelnoj kondensacii metana / – Tekst : neposredstvennyj // Sverhkriticheskie Flyuidy: Teoriya i Praktika.. – 2023. – Т. 18. – № 3. – S. 51-68. - DOI: 10.34984/SCFTP.2023.18.3.005
En
Structural features of mixed La—Al-oxides and stability of their catalytic properties in oxidative coupling of methane. Sverhkriticheskie Flyuidy: Teoriya i Praktika, 3, 51-68 (2023). https://doi.org/10.34984/SCFTP.2023.18.3.005
Key words: extraction, neodymium, carbon dioxide, TODGA, nitric acid, phase equilibrium
Some equilibria in the system Nd3+ —water—nitric acid—TODGA—CO2 (TODGA — N,N,N′,N′-tetraoctyl diglycolamide) and the efficiency of extraction of Nd3+ ions from aqueous solutions into the supercritical (SC) CO2-based phase at 313—353 K and 180—400 bar were studied. It has been shown that in the absence of TODGA, the transfer of Nd3 ions to the SC-phase does not occur. The extraction efficiency increases with decreasing temperature and with increasing concentration of nitric acid (CNA) in the aqueous solution. At 313 K, CNA ≥ 1.5 mol/l, TODGA content not less than 100 mol/g-at. Nd and CO2 pressure ensuring complete dissolution of TODGA (>19 MPa), a complete transfer of Nd3+ to the SC-phase is observed. As the content of neodymium ions in the system increases, the pressure and amount of CO2 required for complete dissolution of TODGA increases too. This is apparently due to a decrease in the intensity of intermolecular interactions in the SC-phase at increasing concentration in it of large and polar Nd complexes with TODGA and nitrate ions.
doi:10.34984/SCFTP.2023.18.3.006
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ГОСТ
7.0.100-2018
Phase equilibria in the system nd<sup>3</sup><sup>+</sup>–water–nitric acid—TODGA–CO<sub>2 </sub> and the efficiency of supercritical fluid extraction of neodymium ions / – Текст : непосредственный // Сверхкритические Флюиды: Теория и Практика.. – 2023. – Т. 18. – № 3. – С. 69-83. - DOI: 10.34984/SCFTP.2023.18.3.006
TRANSLIT
Fazovye ravnovesiya v sisteme Nd<sup>3+</sup>—voda—azotnaya kislota—TODGA—SO<sub>2</sub> i effektivnost' sverhkriticheskoj flyuidnoj ekstrakcii ionov neodima / – Tekst : neposredstvennyj // Sverhkriticheskie Flyuidy: Teoriya i Praktika.. – 2023. – Т. 18. – № 3. – S. 69-83. - DOI: 10.34984/SCFTP.2023.18.3.006
En
Phase equilibria in the system nd<sup>3</sup><sup>+</sup>–water–nitric acid—TODGA–CO<sub>2 </sub> and the efficiency of supercritical fluid extraction of neodymium ions. Sverhkriticheskie Flyuidy: Teoriya i Praktika, 3, 69-83 (2023). https://doi.org/10.34984/SCFTP.2023.18.3.006