model mixture
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Fuel ◽  
2022 ◽  
Vol 309 ◽  
pp. 122130
Author(s):  
Dan Wang ◽  
Tao Zhang ◽  
Lin Yang ◽  
Lianzheng Zhang ◽  
Dongmei Xu ◽  
...  

2021 ◽  
Vol 899 ◽  
pp. 275-280
Author(s):  
Ilya L. Borisov ◽  
Evgenia Grushevenko ◽  
Elena Buinova ◽  
Vladimir Volkov

The paper presents a comparison of the techniques for polydecylmethylsiloxane selective layer coating to the inner and outer sides of a polysulfone hollow fiber support. It has been shown that coating to the outer side allows one to obtain a composite membrane with a higher selectivity for CO2/N2 vapor. A decrease in the number of defects in the selective layer is achieved by increasing the viscosity of the polydecylmethylsiloxane solution. The resulting membrane was characterized in the separation of a model mixture of hydrocarbons, and a high separation selectivity was shown - 12.4 with respect to the n-butane / methane gas pair.


2021 ◽  
Vol 23 (5) ◽  
pp. 703-707
Author(s):  
L. I. Kucherenko ◽  
O. O. Chonka ◽  
O. O. Portna

Today, the important problem is the creation of new decamethoxine and thiotriazoline based drugs for the treatment of stomatitis. The aim of the work is to develop a method for quantitative determination of decamethoxine and thiotriazoline in the model mixture (1:25) by spectrophotometry. Materials and methods. Series 6 model mixtures were made at the ratio of decamethoxine and thiotriazoline 1:25. We used certified substances: thiotriazoline series GTT 3460911 (manufacturer: State Enterprise Chemical Reagents Plant, Kharkiv), decamethoxine series № 010915 (manufacturer: LLC “PHARMCHIM”). Optizen POP spectrophotometer, polyvinyl alcohol, hydrochloric acid, and eosin were used. Results. A method for quantitative determination of decamethoxine and thiotriazoline in MS was developed. It was established that the content of active substances in MS is thiotriazoline from 0.5021 to 0.5096, decamethoxine from 0.0207 to 0.0211. Conclusions. A method for quantitative determination of decamethoxine and thiotriazoline in MS has been developed. The method of quantitative determination of decamethoxine and thiotriazoline in MS is reproducible.


Author(s):  
O. V. Korobova ◽  
L. K. Samarska ◽  
S. L. Humenjuk ◽  
M. I. Bereziyk ◽  
M. V. Yurkevych

Aim of our war was to investigate the degradation of diazinon in the model mixture in comparison with the experimental preparation. Methyl alcohol was used as a basis for the manufacture of diazinon drops and the model mixture. The concentration of diazinon was determined by reversed-phase high performance liquid chromatography on the third, fourteenth and twenty-first day after preparation of the model mixture and experimental preparation when stored at room temperature. Despite the large number of publications studying the degradation of diazinon under the influence of various factors, there is a need to study this process in mixtures of a specific composition, in particular in new veterinary drugs that have not yet been studied. This article presents the results of determining the content of diazinon in 10% of the drug and the model mixture based on methyl alcohol. The analyzes were performed on a Knauer liquid chromatograph with a spectrophotometric detector equipped with a Luna® Omega Polar C 18 150 × 4.6 mm column filled with a 5 μm particle sorbent from Phenomenex with a universal C 18 pre-column 4 × 3.0 mm ID. Mobile phase: degassed mixture of acetonitrile: water in the ratio 65:35, flow rate was 1.1 ml/min, temperature of the column was ambient. Diazinone was detected at 245 nm. Injection volume was 0.050 ml and the time of one separation – 20 minutes. The appearance of an unknown peak on the 3 min chromatogram of the solution of the production experimental preparation was revealed. On the twenty-first day of storage of the experimental drug, the content of diazinon decreased to 34 % of the stated amount. On the third and twenty-first day of storage of the model mixture, a decrease in the content of diazinon by 16 % and 79%, respectively, and the appearance of an additional peak were observed. The use of methyl alcohol with other components is likely to be a factor in the breakdown of diazinon in the drug. According to the recipe of the drug, methanol is about half the content of ingredients. This composition does not provide stability of the proposed dosage form of the drug. The next step will be to study the effect of other solvents on maintaining the stated concentration of diazinon.


2021 ◽  
Vol 134 (3) ◽  
pp. 26-28
Author(s):  
◽  
A. M. Mazgarov ◽  
A. F. Vildanov ◽  
F. A. Korobkov ◽  
N. I. Kuznechova ◽  
...  

The adsorption capacity of a number of zeolites during the purification of the n-hexane + dimethyl sulfide model mixture from dimethyl sulfide was studied. Under the selected conditions (21–24°C, flow rate of the model mixture —120 ml/h, adsorbent volume — 50 ml) ultra-stable zeolite exhibits the greatest sulfur capacity 2.3% by weight.


Author(s):  
Sergiy Bochkarev ◽  
Viktoria Mazaeva ◽  
Tetiana Ovsiannikova ◽  
Oksana Zviahintseva

When introducing plant and animal protein products, in addition to nutritional value, it is advisable to assess their physicochemical properties and technological indicators, in particular, homogeneity and consistency stability. The aim of research is to determine the effect of consistency stabilizers on the viscosity of a reconstituted hypertonic drink for athletes based on flaxseed cake, sesame seeds and whey protein concentrate. The mass fraction of protein in the model dry mixture of a hypertonic drink, as well as in its individual components by the Kjeldahl method, the mass fraction of fiber – by the gravimetric method, the mass fraction of lipids – by the extraction-gravimetric method, the mass fraction of moisture – by the thermogravimetric method. The mass fraction of ash in the mixtures was carried out by the method of incineration followed by calcining the mineral residue at a temperature of 450 ... 600 °C. The effective viscosity in the reduced samples of mixtures without and with the addition of stabilizers was determined on a rotational viscometer "Rheotest 2". For the planning of the experiment and data processing, mathematical methods were applied using the Microsoft Office Excel 2003 software package. The chemical composition of individual components and a model dry mixture of a hypertonic drink for the nutrition of athletes, including the content of compounds that have a stabilizing effect on the restored product, has been investigated. It has been proved that the effective viscosity of the reconstructed model mixture in comparison with the effective viscosity of the individual components of the mixture nonaditively increases. The mutual influence of the consistency stabilizers (gum arabic (E 414) and carboxymethylcellulose (E 466)) on the value of the effective viscosity of the reconstituted hypertonic drink was investigated. The developed model mixture of a hypertonic drink is recommended to be used for the development of competitive dry mixtures of hypertonic drinks of plant and animal origin for the nutrition of athletes


Molecules ◽  
2020 ◽  
Vol 25 (21) ◽  
pp. 5061
Author(s):  
Marine Canton ◽  
Jane Hubert ◽  
Stéphane Poigny ◽  
Richard Roe ◽  
Yves Brunel ◽  
...  

For scientific, regulatory, and safety reasons, the chemical profile knowledge of natural extracts incorporated in commercial cosmetic formulations is of primary importance. Many extracts are produced or stabilized in glycerin, a practice which hampers their characterization. This article proposes a new methodology for the quick identification of metabolites present in natural extracts when diluted in glycerin. As an extension of a 13C nuclear magnetic resonance (NMR) based dereplication process, two complementary approaches are presented for the chemical profiling of natural extracts diluted in glycerin: A physical suppression by centrifugal partition chromatography (CPC) with the appropriate biphasic solvent system EtOAc/CH3CN/water 3:3:4 (v/v/v) for the crude extract fractionation, and a spectroscopic suppression by presaturation of 13C-NMR signals of glycerin applied to glycerin containing fractions. This innovative workflow was applied to a model mixture containing 23 natural metabolites. Dereplication by 13C-NMR was applied either on the dry model mixture or after dilution at 5% in glycerin, for comparison, resulting in the detection of 20 out of 23 compounds in the two model mixtures. Subsequently, a natural extract of Cedrus atlantica diluted in glycerin was characterized and resulted in the identification of 12 metabolites. The first annotations by 13C-NMR were confirmed by two-dimensional NMR and completed by LC-MS analyses for the annotation of five additional minor compounds. These results demonstrate that the application of physical suppression by CPC and presaturation of 13C-NMR solvent signals highly facilitates the quick chemical profiling of natural extracts diluted in glycerin.


2020 ◽  
Vol 8 (2) ◽  
pp. 321-328
Author(s):  
Artem Samoylov ◽  
Natal’ya Suraeva ◽  
Mariya Zaytseva ◽  
Vera Rachkova ◽  
Madinat Kurbanova ◽  
...  

Introduction. In view of the ongoing research into the negative effects of fruit juice on human health, we aimed to study the subchronic toxicity of apple juice, a model mixture based on its components, and ethanol on biomass growth, cellular oxidative enzymes, and chromosomal abnormalities in Allium cepa roots. Study objects and methods. Our objects of study included clarified apple juice and its components such as fructose, glucose, sucrose, D-sorbitol, and malic acid. After treating Allium cepa roots with apple juice and a model mixture in different concentrations, we analyzed their toxic effects on biomass growth, malondialdehyde levels, as well as the nature and frequency of proliferative and cytogenetic disorders in the plant tissues. Results and discussion. The incubation in an aqueous solution of apple juice at a concentration of 1:5 inhibited the growth in root mass by 50% compared to the control (water). The mitotic index of cells decreased with higher concentrations of juice, reaching zero at a 1:5 dilution. The fructose and model solutions in the same concentrations appeared less toxic in relation to cell mitosis and root mass growth. Although malondialdehyde levels increased in the onion roots treated with juice and model solutions, they were twice as low as in the control due to the juice’s antioxidant activity. Adding 1% ethanol to the 1:2 diluted juice abolished the effect of acute toxicity on root growth and reduced malondialdehyde levels by 30%. Conclusion. The study revealed a complex of interdependent biomarkers of apple juice responsible for its subchronic toxicity in Allium cepa roots. These data can be used to create biological response models based on the approaches of systems biology and bioinformatics.


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