STUDY OF PHENOLIC COMPOUNDS IN THE ABOVE-GROUND PART OF CERTAIN SPECIES OF THE GENUS INULA BY HPLC

2020 ◽  
pp. 68-73
Author(s):  
Kruglaya A.A.
Keyword(s):  
Particle Size ◽  
Ferulic Acid ◽  
Plant Material ◽  
Aerial Part ◽  
Room Temperature ◽  
Wild Plants ◽  
Water Mixture ◽  
Acid Acid ◽  
Paper Filter ◽  
Ground Part

Studied the cоmpоsitiоn оf phenоlic cоmpоunds cоntained in the aerial part оf wild plants оf the genus Inula, cоllected in different areas оf the Nоrthern Caucasus (Inula оrientalis, Inula salicina, Inula germanica). The HPLC methоd identified 20 phenоlic cоmpоunds in the aerial part оf the Inula оrientalis, identified 17 cоmpоunds (tannin, galic acid, chlоrоgenic acid, chicоreic acid, ferulic acid and оther cоmpоunds), in the aerial part оf the Inula aspera, 19 cоmpоunds оf phenоlic nature were fоund, 12 cоmpоunds were identified (dihydrоcоumarin, hyperоside, galic acid, chlоrоgenic acid, and оther cоmpоunds), in the aerial part оf the Inula germanica, 22 phenоlic cоmpоunds were fоund, 14 cоmpоunds were identified (dihydrоcоumarin, hyperоside, rutin, chlоrоgenic acid, and оther cоmpоunds). The study оf the qualitative cоmpоsitiоn оf phenоlic cоmpоunds was carried оut оn a high-perfоrmance liquid chrоmatоgraph оf the firm "GILSTОN", mоdel 305, FRANCE; manual injectоr, mоdel RHEОDYNE 7125 USA, fоllоwed by cоmputer prоcessing оf the research results using the Multichrоm prоgram fоr Windоws. The system - methanol - water - concentrated phosphoric acid - tetrahydrofuran, in the ratio 370: 570: 5: 60 was chosen as the mobile phase. The stationary phase was a 4.6 x 250 mm KROMASIL C18 metal column with a particle size of 5 microns. According to the method, the analysis was carried out at room temperature. The flow rate of the eluent is 0.8 ml / min. Analysis duration 60 min. Detectiоn was carried оut using a GILSTОN UV/VIS mоdel 151 UV detectоr at a wavelength оf 254 nm. Fоr research, crushed plant material tо a particle size passing thrоugh a sieve with a hоle diameter оf 2 mm was placed in a flask with a capacity оf 100 ml, 20 ml оf 70% ethyl alcоhоl was added, attached tо a reflux cоndenser and heated in a bоiling water bath fоr 1 hоur frоm the mоment the alcоhоl-water mixture bоiled in the flask. After cооling, the mixture was filtered thrоugh a paper filter intо a 25 ml vоlumetric flask and diluted with ethyl alcоhоl 70% up tо the mark. In parallel, a series оf 0.05% reference sоlutiоns in 70% ethyl alcоhоl was prepared: cinnamic acid, chicoric acid, ferulic acid, tannin, epicatechin, catechin, naringenin, dicoumarin, dihydroquercetin, rutin, quercetin, luteolin, luteolin-7-glycoside, kaempferol, coumarin, hyperoside, hesperidin, apigenin, gallic acid acid, neochlorogenic acid.

Electroacoustic Study of n-Hexadecane/Water Emulsions

2001 ◽  
Vol 54 (8) ◽  
pp. 503 ◽  
Author(s):  
Linggen Kong ◽  
James K. Beattie ◽  
Robert J. Hunter
Keyword(s):  
Particle Size ◽  
Zeta Potential ◽  
Volume Fraction ◽  
Sodium Dodecyl ◽  
Surfactant Solution ◽  
Minimum Size ◽  
Water Mixture ◽  
Concentrated Suspensions ◽  
Minimum Concentration ◽  
Median Diameter

n-Hexadecane-in-water emulsions were investigated by electroacoustics using a prototype of an AcoustoSizer-II apparatus. The emulsions were formed by passing the stirred oil/water mixture through a homogenizer in the presence of sodium dodecyl sulfate (SDS) at natural pH (6–7). With increasing oil-volume fraction, the particle size increased linearly after 5 and also after 20 passages through the homogenizer, suggesting that surface energy was determining particle size. For systems in which the surfactant concentration was limited, the particle size after 20 passages approached the value dictated by the SDS concentration. With ample surfactant present, the median diameter was a linear function of the inverse of the total energy input as measured by the number of passes. There was, however, a limit to the amount of size reduction that could be achieved in the homogenizer, and the minimum size was smaller at smaller volume fractions. Dilution of the emulsion with a surfactant solution of the same composition as the water phase had a negligible effect on the particle size and changed the zeta potential only slightly. This confirms results from previous work and validates the equations used to determine the particle size and zeta potential in concentrated suspensions. The minimum concentration of SDS that could prevent the emulsion from coalescing for the system with 6% by volume oil was 3 mM. For this dilute emulsion, the particle size decreased regularly with an increase in SDS concentration, but the magnitude of the zeta potential went through a strong maximum at intermediate surfactant concentrations.

Photophysical Studies of a Hemicyanine Dye (LDS-698) in Dioxane−Water Mixture, in Different Alcohols, and in a Room Temperature Ionic Liquid

2009 ◽  
Vol 113 (19) ◽  
pp. 6826-6833 ◽  
Author(s):  
Debabrata Seth ◽  
Souravi Sarkar ◽  
Rajib Pramanik ◽  
Chiranjib Ghatak ◽  
Palash Setua ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Room Temperature ◽  
Room Temperature Ionic Liquid ◽  
Water Mixture ◽  
Hemicyanine Dye ◽  
Photophysical Studies

Sintering of Silver Nanoparticles at Room-Temperature for Conductive Ink Applications

2018 ◽  
Vol 775 ◽  
pp. 144-148 ◽  
Author(s):  
Bethel Faith Y. Rezaga ◽  
Mary Donnabelle L. Balela
Keyword(s):  
Particle Size ◽  
Ag Nanoparticles ◽  
Room Temperature ◽  
Average Diameter ◽  
Aqueous System ◽  
Ag Nanoparticle ◽  
Nacl Solution ◽  
Cellulose Acetate Film ◽  
Sintered Ag ◽  
Nanoparticle Ink

Silver (Ag) nanoparticles synthesized in an aqueous system was sintered at room temperature using NaCl solution. The Ag nanoparticles have an average diameter of about 24 nm. After dispersing the Ag nanoparticles in 50mM NaCl solution, a significant increase in particle size to about 206 nm was observed. On the other hand, the particle size was also increased to about 175 nm when the Ag nanoparticles were printed and then 50mM NaCl solution was dropped onto the printed Ag nanoparticles. The enlargement of particle size was accompanied by the increase in conductivity of the Ag nanoparticle ink. The resistance was reduced from 57.7 to 6.5 and 6.7 ohms for the as-prepared and sintered Ag nanoparticles using two different treatments, respectively. The sintered Ag nanoparticle ink formulation exhibit high conductivity when drawn on both cellulose acetate film and bond paper even after bending and folding of the substrates.

NANOEMULSIONS BASED ON LIPOIC ACID DERIVATIVES WITH VARIOUS ALCOHOLS: PRODUCTION AND INFLUENCE ON FUNCTIONAL ACTIVITY OF PLATELETS

2020 ◽  
pp. 461-464
Author(s):  
A. Sinebryukhova ◽  
A. Shipelova ◽  
E. Darnotuk ◽  
A. Chekanov ◽  
O. Baranova ◽  
...  
Keyword(s):  
Particle Size ◽  
Arachidonic Acid ◽  
Lipoic Acid ◽  
Encapsulation Efficiency ◽  
Room Temperature ◽  
Optimal Conditions ◽  
Pluronic F68 ◽  
Long Term Storage ◽  
Term Storage

The optimal conditions were selected for obtaining homogeneous nanoemulsions (NE) of lipoic acid conjugates (LA-conjugates) based on Pluronic F68 (1,8%) with a particle size not exceeding 400 nm, characterized by 97±2% encapsulation efficiency of substances in nanoparticles (NP). A heterogeneous NE (polydispersity index, PDI>0,3) with the derivative of LA and myo-inositol based on phosphatidylcholine (PC, C = 3 mg/ml) was also obtained consisting of 2 particle fractions: 20–70 nm (27%) and 122–212 nm (73%). The obtained NEs with LA-conjugates based on Pluronic F68 and PC were stable during long-term storage (more than 12 months) at room temperature. The effect of the obtained NEs of LA-conjugates on platelet aggregation (Pt) caused by arachidonic acid (AA) was determined, and a mechanism of their action was proposed.

scholarly journals Initial Investigation into the Leaching of Manganese from Nodules at Room Temperature with the Use of Sulfuric Acid and the Addition of Foundry Slag—Part I

Minerals ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 565 ◽  
Author(s):  
Norman Toro ◽  
Nelson Herrera ◽  
Jonathan Castillo ◽  
Cynthia Torres ◽  
Rossana Sepúlveda
Keyword(s):  
Particle Size ◽  
Sulfuric Acid ◽  
Acid Concentration ◽  
Room Temperature ◽  
Sulfuric Acid Concentration ◽  
Extraction Rate ◽  
Molar Ratio ◽  
Independent Variables ◽  
Initial Investigation ◽  
Optimization Methodology

In this study, the surface optimization methodology was used to assess the effect of three independent variables—time, particle size and sulfuric acid concentration—on Mn extraction from marine nodules during leaching with H2SO4 in the presence of foundry slag. The effect of the MnO2/Fe ratio and particle size (MnO2) was also investigated. The maximum Mn extraction rate was obtained when a MnO2 to Fe molar ratio of 0.5, 1 M of H2SO4, −320 + 400 Tyler mesh (−47 + 38 μm) nodule particle size and a leaching time of 30 min were used.

Magnesium Aluminate Nanoparticles for Chemical Detoxification of Sarin and Soman

2020 ◽  
Vol 20 (6) ◽  
pp. 3547-3553
Author(s):  
G. K. Prasad ◽  
L. K. Pandey ◽  
J. Praveen Kumar ◽  
K. Ganesan ◽  
J. Acharya ◽  
...  
Keyword(s):  
Particle Size ◽  
Spinel Structure ◽  
Room Temperature ◽  
Chemical Warfare Agents ◽  
Nitrogen Adsorption ◽  
Chemical Warfare ◽  
Magnesium Aluminate ◽  
Nitrogen Adsorption Isotherm ◽  
Type Iv ◽  
Warfare Agents

The solutions of Mg(NO3)2, Al(NO3)3, and (NH4)2CO3 were mixed at pH 8 and then heated at 95 °C for 4 h, aged at room temperature for 16 h, and calcined at 650 °C for 4 h to obtain magnesium aluminate nanoparticles. The obtained materials exhibited spinel structure with the particle size being 6 to 26 nm. The nanoparticles demonstrated type IV nitrogen adsorption isotherm, typical of mesoporosity with a surface area of 325 m2/g. They were utilized for studies on chemical detoxification of deadly chemical warfare agents such as sarin and soman. Our results showed that the magnesium aluminate nanoparticles effectively decontaminated more than 99% of sarin and soman within 8–10 min when used at a ratio of 1:50–60% w/w.

Fusing of Silver Nanoparticles at Room Temperature Using Halide Solutions for Conductive Inks

2020 ◽  
Vol 833 ◽  
pp. 181-185 ◽  
Author(s):  
Bethel Faith Y. Rezaga ◽  
Mary Donnabelle L. Balela
Keyword(s):  
Particle Size ◽  
Ag Nanoparticles ◽  
Room Temperature ◽  
Average Diameter ◽  
Aqueous System ◽  
Ag Nanoparticle ◽  
Nacl Solution ◽  
Halide Solution ◽  
Sintered Ag ◽  
Nanoparticle Ink

Fusing of silver (Ag) nanoparticles synthesized in an aqueous system was observed at room temperature using halide solutions. The as-synthesized Ag nanoparticles have an average diameter of about 24 nm. After dispersing the Ag nanoparticles in a halide solution, a significant increase in particle size to about 188-197 nm was observed. The enlargement of particle size was accompanied by the increase in conductivity of the Ag nanoparticle ink. The resistance was reduced from 110 kiloohms to 35 and 9.3 ohms for the as-prepared and sintered Ag nanoparticles using NaBr and NaCl solution, respectively.

Preparation of Nanocrystalline Fe2O3 Powder by Cryomilling with Liquid Nitrogen and its Magnetic Property

2020 ◽  
Vol 993 ◽  
pp. 806-810
Author(s):  
Zhi Wei Zhang ◽  
Bing Wei Luo ◽  
Hai Tao Zhou ◽  
Fen Wang
Keyword(s):  
Particle Size ◽  
Grain Size ◽  
Magnetic Property ◽  
Liquid Nitrogen ◽  
Room Temperature ◽  
Single Phase ◽  
Rapid Preparation ◽  
Mean Particle Size ◽  
Milling Temperature ◽  
The Mean

Rapid preparation of nanocrystalline γ-Fe2O3 powder with superparamagnetism was realized by cryomilling commercial Fe2O3 powder using liquid nitrogen. The effects of milling temperature and duration on the grain size, phase and microstructure of the nanocrystalline Fe2O3 powder were analyzed. Magnetic property of the nanocrystalline γ-Fe2O3 powder was also tested by magnetometer at room temperature. The results demonstrate that nanocrystalline γ-Fe2O3 powder with single phase can be prepared rapidly by cryomilling with liquid nitrogen. The mean particle size of γ-Fe2O3 powder can be reduced from 300 nm to 13 nm by cryomilling at −130 °C within 3 hours. The nanocrystalline γ-Fe2O3 powder shows superparamagnetism at room temperature.

Hydrogen Sulfide Separation from Biogas Using Laterite Soil Adsorbent

2020 ◽  
Vol 988 ◽  
pp. 144-150
Author(s):  
Sanggono Adisasmito ◽  
Carolus Borromeus Rasrendra ◽  
M. Qori Alfadhli ◽  
M. Fauzan Al Ghifary
Keyword(s):  
Particle Size ◽  
Adsorption Capacity ◽  
Room Temperature ◽  
Biogas Production ◽  
Separation Process ◽  
High Adsorption ◽  
Laterite Soil ◽  
Adsorption Column ◽  
Bed Height ◽  
High Adsorption Capacity

Biogas production contributes as an alternative renewable energy but its emissions contain sulphuric components which needs to be separated because it can cause damage to the environment. The method used in separation is adsorption with laterite soil because the price is cheap, easy to obtain, and can occur at room temperature. The purpose of this study is to determine the conditions of the adsorbent in the adsorption column which can provide a high adsorption capacity. The separation process is carried out by flowing biogas with a flow rate of 1.5 liters/minute to the adsorption column containing laterite soil. Reducing the particle size of the adsorbent from 6 mesh to 21 mesh will increase the adsorption capacity to 2.13 times, ie from 7.3 to 14.2 mg H2S/g adsorbent. The addition of bed height from 7 cm to 12 cm will increase the adsorption capacity from 6.7 to 7.9 mg H2­S/g adsorbent at 6 mesh particle size. The addition of bed height from 7 cm to 12 cm will increase the adsorption capacity from 13.5 to 15.0 mg H2S/g adsorbent at 21 mesh particle size. The laterite soil adsorbent with a particle size of 21 mesh has the highest adsorption capacity of 15.0 mg H2S/g adsorbent.

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