Research on the Microwave-Assisted Supercritical CO2 Extraction of Alkaloids from Gynura segetum (Lour.) Merr.

2014 ◽  
Vol 988 ◽  
pp. 390-396 ◽  
Author(s):  
Qin Fang Lu ◽  
Li Fang Pan ◽  
Ming Chen ◽  
Yong Qiu ◽  
Bao Hua Xie
Keyword(s):  
Infrared Spectroscopy ◽  
Microwave Irradiation ◽  
Extraction Method ◽  
Ethanol Concentration ◽  
Irradiation Time ◽  
Experimental Conditions ◽  
Soaking Time ◽  
Microwave Assisted ◽  
Water Solvent ◽  
Main Component

In this study, the alkaloids from Gynura Segetum (Lour.) Merr. were extracted based on the microwave-assisted supercritical CO2 extraction technique. Before extraction, the powder of Gynura Segetum (Lour.) Merr. was firstly soaked with ethanol-water solvent and irradiated by microwave The experimental conditions including ethanol concentration, soaking time and microwave irradiation time were carefully studied, and the best efficiency could be obtained when the ethanol concentration, soaking time and microwave irradiation time were respectively 90%, 10 h and 2 min. Meanwhile, a parallel experiment with only supercritical CO2 extraction was also carried out as a comparison. The results indicated the efficiency of microwave-assisted supercritical CO2 extraction method was better for extracting the alkaloids from Gynura Segetum (Lour.) Merr. samples. Finally, the structures of the crystals extracted from the Gynura Segetum (Lour.) Merr. were analyzed by infrared spectroscopy, and the seneciphylline was found as the main component of the crystals.

scholarly journals Extraction of Phytosterol Concentration in Different Legume Pods by Using Microwave-Assisted Hydrodistillation

2019 ◽  
Vol 19 (3) ◽  
pp. 796
Author(s):  
Noormazlinah Noormazlinah ◽  
Norlaili Hashim ◽  
Abdurahman Hamid Nour ◽  
Mimi Sakinah Abdul Munaim ◽  
Maria Pilar Almajano ◽  
...  
Keyword(s):  
Bioactive Compounds ◽  
Microwave Power ◽  
Ethanol Concentration ◽  
Irradiation Time ◽  
Optimal Conditions ◽  
Solvent Concentration ◽  
Visible Spectroscopy ◽  
Optimum System ◽  
Microwave Assisted ◽  
Extraction Parameters

The traditional ways in the extraction of bioactive compounds using conventional methods are disadvantageous from both economic and environmental perspectives. In this, the potential of microwave-assisted hydrodistillation conditions for extraction of phytosterol from legume pods was investigated. Salkowski test performed on the legume pod has shown the reddish brown in all sample which confirmed the presence of phytosterol qualitatively. Liebermann-Burchard procedure and ultraviolet-visible spectroscopy (UV-Vis) apparatus were used to study the concentration of phytosterol at different extraction parameters which are temperature (25–80 °C), solvent concentration (50–100% v/v), irradiation time (1–10 min) and microwave power (400–800 W). The optimal conditions for highest yield of extract (0.219 mg/L) were obtained at a microwave power of 600 W, the irradiation time of 6 min, and ethanol concentration of 75% v/v. Results obtained in this study have shown the capability of microwave-assisted hydrodistillation in the extraction of phytosterol from legume pod. Further works are nevertheless required to provide a deeper understanding of the mechanisms involved to facilitate the development of an optimum system applicable to the industry.

Meso-mechanics simulation analysis of microwave-assisted mineral liberation

2015 ◽  
Author(s):  
Qin Like ◽  
Dai Jun ◽  
Yuan Liqun
Keyword(s):  
Energy Consumption ◽  
Microwave Irradiation ◽  
Power Density ◽  
Microwave Power ◽  
Mineral Content ◽  
Crystal Size ◽  
Irradiation Time ◽  
Mineral Crystal ◽  
Microwave Assisted ◽  
Time And Energy

Microwave-assisted crushing and grinding can improve efficiency and reduce energy consumption. This paper takes rock grains with galena and calcite as the research object to establish a two-dimensional computational model through the finite difference software FLAC2D. It analyzes the process and law of mineral boundary failure under microwave irradiation, and assesses the effects of four factors, namely, microwave irradiation time, power density, mineral crystal size, and mineral content, on mineral boundary failure. Results indicate an optimal microwave irradiation period for the rapid failure of mineral boundary. Moreover, irradiation time and energy consumption can be reduced by increasing the microwave power density. However, irradiation time and energy consumption are basically unchanged when the microwave power density is above a certain threshold. Mineral content slightly affects the microwave irradiation time, whereas mineral crystal size significantly affects the microwave irradiation time. In addition, a larger-sized mineral crystal requires less irradiation time and energy consumption to reach the same failure rate. However, irradiation time and energy consumption slightly change when the crystal size is larger than a certain value.

scholarly journals Screening of Microwave-Assisted-Batch Extraction Parameters for Recovering Total Phenolic and Flavonoid Contents from Chromolaena odorata Leaves through Two-Level Factorial Design

2019 ◽  
Vol 19 (2) ◽  
pp. 511 ◽  
Author(s):  
Oluwaseun Ruth Alara ◽  
Abdurahman Hamid Nour ◽  
Siti Kholijah Binti Abdul Mudalip
Keyword(s):  
Factorial Design ◽  
Microwave Power ◽  
Ethanol Concentration ◽  
Irradiation Time ◽  
Power Level ◽  
Feed Ratio ◽  
Total Phenolic ◽  
Chromolaena Odorata ◽  
Microwave Assisted ◽  
Microwave Power Level

Microwave-assisted extraction (MAE) of phenolic compounds from Chromolaena odorata leaves was investigated using one-factor-at-a-time (OFAT) and two-level factorial design. The MAE parameters studied were irradiation time (A: 1–5 min); microwave power level (B: 400-800 W); extraction temperature (C: 60–80 °C); solvent/feed ratio (D: 8:1–14:1 mL/g); and ethanol concentration (E: 20–60% v/v). The optima yields of TPC and TFC were 56.13 mg GAE/g d.w. and 44.78 mg QE/g d.w., respectively were achieved from MAE of C. odorata leaf at irradiation time of 2 min, microwave power of 600 W, temperature of 60 °C, solvent:feed ratio of 10:1 mL/g, and ethanol concentration of 40% v/v through one-factor-at-time (OFAT) experimental trials. The results obtained from a two-level factorial design experiments reflected that only ethanol concentration (20–60% v/v), irradiation time (1–5 min) and microwave power level (400–800 W) had significant effects on the yields of total phenolic content (TPC) and total flavonoid content (TFC) from C. odorata leaves (p < 0.05). However, temperature and solvent/feed ratio was not significant. In addition, the interactions AB (irradiation time and microwave power) and AE (irradiation time and ethanol concentration) contributed greatly to the recovery yields.

scholarly journals A Green Synthesis of a Novel Calix[4]Resorcinarene from 7-Hydroxycitronellal Using Microwave Irradiation

2018 ◽  
Vol 18 (1) ◽  
pp. 53
Author(s):  
Ratnaningsih Eko Sardjono ◽  
Iqbal Musthapa ◽  
Iis Rosliana ◽  
Fitri Khoerunnisa ◽  
Galuh Yuliani
Keyword(s):  
Energy Consumption ◽  
Reaction Time ◽  
Microwave Irradiation ◽  
Irradiation Time ◽  
Microwave Oven ◽  
Conventional Heating ◽  
Heating Method ◽  
Microwave Assisted ◽  
Domestic Microwave Oven ◽  
Waste Production

A new versatile macromolecule cyclic C-3,7-dimethyl-7-hydroxycalix[4]resorcinarene (CDHHK4R) has been synthesized from a fragrance agent, 7-hydroxycitronellal, via microwave irradiation. The reaction utilized a domestic microwave oven at various irradiation time and power to yield an optimum condition. As a comparison, the conventional heating method was also employed for the synthesis of the same calix[4]resorcinarene. Compared to the conventional method, microwave-assisted reaction effectively reduced the reaction time, the amount of energy consumption and the waste production. It is found that the synthesis of CDHHK4R by microwave irradiation yielded 77.55% of product, higher than by conventional heating which was only 62.17%.

Study on Preparation of Activated Carbon from Corncob Furfural Residue with ZnCl2 by Microwave Irradiation

2010 ◽  
Vol 152-153 ◽  
pp. 1322-1327 ◽  
Author(s):  
Cong Jin Chen ◽  
Long Bin Wei ◽  
Peng Cheng Zhao ◽  
Yue Li ◽  
Hua Yu Hu ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Microwave Irradiation ◽  
Mass Concentration ◽  
Ph Value ◽  
Irradiation Time ◽  
Carbon Yield ◽  
Solution Ph ◽  
Soaking Time ◽  
Furfural Residue

In this paper, the feasibility of preparing activated carbon from corncob furfural residue with ZnCl2 by microwave irradiation was studied. The effect of the ratio by weight of ZnCl2 to corncob furfural residue, ZnCl2 solution soaking time, microwave irradiation time and the pH value of ZnCl2 solution on the quality of activated carbon was investigated. On the condition that the microwave power is 800 W and ZnCl2 solution mass concentration is 50%, the best technological parameter on preparing activated carbon with ZnCl2 by microwave irradiation is obtained: at the ratio of 3.5:1 by weight of ZnCl2 to corncob furfural residue, microwave irradiation time is 20 min, ZnCl2 solution soaking time is 12 h, the pH value of ZnCl2 solution is 2, the activated carbon yield reached 33.1% and the decolorizing capacity for methylene blue is 202.5 mg/g, the product is used in treating Cr6+ solution(pH value 4.0, concentration 50 mg/L), its adsorption capacity of Cr6+ is 7.583 mg/g.

scholarly journals Protic Ionic Liquids as Efficient Solvents in Microwave-Assisted Extraction of Rhein and Emodin from Rheum palmatum L.

Molecules ◽  
2019 ◽  
Vol 24 (15) ◽  
pp. 2770 ◽  
Author(s):  
Yunchang Fan ◽  
Zeyu Niu ◽  
Chen Xu ◽  
Lei Yang ◽  
Tuojie Yang
Keyword(s):  
Ionic Liquids ◽  
Microwave Irradiation ◽  
Irradiation Time ◽  
Chinese Herb ◽  
Microwave Assisted Extraction ◽  
Active Components ◽  
Protic Ionic Liquids ◽  
Microwave Assisted ◽  
Rheum Palmatum ◽  
Assisted Extraction

Rheum palmatum L. (R. palmatum L.) is a traditional Chinese herb and food, in which rhein and emodin are the main bioactive components. The extraction of the two compounds from R. palmatum L. is, thus, of great importance. In this work, protic ionic liquids (PILs) were applied in the microwave-assisted extraction (MAE) of rhein and emodin from R. palmatum L., which avoids the toxicity of organic solvents. The results of the present study indicate that PILs possessing higher polarity exhibit higher extraction ability due to their stronger absorption ability for microwave irradiation. Compared with conventional solvents, such as methanol, trichloromethane, and deep eutectic solvents (DESs), the PIL, 1-butyl-3-himidazolium methanesulfonate ([BHim]MeSO3) reported herein is more efficient. The selected extraction conditions of liquid–solid ratio, microwave irradiation time, microwave irradiation power, and PIL concentration were 40 g·g−1, 50 s, 280 W, and 80%, respectively. Under the selected conditions, the extraction yields of rhein and emodin were 7.8 and 4.0 mg·g−1, respectively. These results suggest that PILs are efficient extraction solvents for the separation of active components from natural products.

scholarly journals TWO LEVEL FACTORIAL SCREENING OF MICROWAVE-ASSISTED EXTRACTION PARAMETERS FOR THE RECOVERY OF PHENOLIC COMPOUNDS FROM VERNONIA CINEREA LEAF

2019 ◽  
Vol 5 (1) ◽  
pp. 16-28
Author(s):  
Oluwaseun Ruth Alara ◽  
Nour Hamid Abdurahman ◽  
John Adewole Alara
Keyword(s):  
Phenolic Compounds ◽  
Microwave Power ◽  
Ethanol Concentration ◽  
Irradiation Time ◽  
Total Phenolic ◽  
Microwave Assisted Extraction ◽  
Microwave Assisted ◽  
Assisted Extraction ◽  
Vernonia Cinerea ◽  
Phenolics Compounds

Vernonia cinerea is one of the medicinal plants with several potentials for treating different ailments. In the present study, Microwave-assisted extraction (MAE) was employed in extracting phenolics compounds from this plant. However, different factors that affect this extraction method in the recovery of phenolics compounds abound, these factors need to be screened to determine actual contributing factor in order to minimize cost. Irradiation time (1-5 min), ethanol concentration (20-60% v/v), microwave power (40-80 W), extraction temperature (40-80 oC), and feed/solvent (1:10 - 1:18 g/mL) have been screened using two-factorial design for the recoveries of phenolic compounds from V. cinerea leaves. The results obtained in this study indicated that only microwave power, ethanol concentration, irradiation time and feed/solvent contributed to recoveries of total phenolic content (TPC) and total flavonoid content (TFC) from V. cinerea leaves. Thus, these factors at these ranges can be further optimized to obtain optimal yields of phenolic compounds from V. cinerea leaves.

scholarly journals Microwave-assisted Synthesis of ZnO Nanoparticles Stabilized with Gum Arabic: Effect of Microwave Irradiation Time on ZnO Nanoparticles Size and Morphology

2019 ◽  
Vol 14 (1) ◽  
pp. 182 ◽  
Author(s):  
Norlin Pauzi ◽  
Norashikin Mat Zain ◽  
Nurul Amira Ahmad Yusof
Keyword(s):  
Microwave Irradiation ◽  
Zno Nanoparticles ◽  
Irradiation Time ◽  
Nanoparticle Synthesis ◽  
Gum Arabic ◽  
High Energy ◽  
Conventional Heating ◽  
Microwave Assisted Synthesis ◽  
Microwave Assisted ◽  
Size And Morphology

The conventional heating methods of nanoparticle synthesis regularly depend on the energy inputs from outer heat sources that resulted high energy intake and low reaction competences. In this paper ZnO nanoparticles stabilized with gum arabic are synthesized using precipitating method assisted by simple and cost effective microwave heating technique. The objective of this work is to investigate the effect of microwave irradiation time towards ZnO nanoparticles morphology and size. The effect of microwave irradiation time has been investigated at 2, 4, 6, and 10 minutes. Dynamic Light Scattering (DLS) was employed to measure the size of ZnO nanoparticles. Ultraviolet–Visible spectroscopy (UV-vis), Fourier-Transform Infrared Spectroscopy (FTIR) and X-Ray Diffraction (XRD) were used for the characterization of the ZnO nanoparticles. UV-vis absorption spectrum was found in the range of 350 nm indicating the absorption peak of ZnO nanoparticles. FTIR spectra showed peaks range from 424 to 475 cm–1 which indicating standard of Zn–O stretching. The presence of (100), (002), and (101) planes were apparent in the XRD result, indicating the crystalline phase of ZnO nanoparticles. The increase in the microwave irradiation time affected the processes of nucleation and crystal growth promoted larger ZnO nanoparticles size. Microwave irradiation time at 2 minutes was selected as the best microwave irradiation time for smallest ZnO nanoparticles averaging about 168 nm sizes based on DLS analysis. Copyright © 2019 BCREC Group. All rights reservedReceived: 1st October 2018; Revised: 22nd November 2018; Accepted: 12nd December 2018; Available online: 25th January 2019; Published regularly: April 2019How to Cite: Pauzi, N., Zain, N.M., Yusof, N.A.A. (2019). Microwave-assisted Synthesis of ZnO Nanoparticles Stabilized with Gum Arabic: Effect of Microwave Irradiation Time on ZnO Nanoparticles Size and Morphology. Bulletin of Chemical Reaction Engineering & Catalysis, 14 (1): 182-188 (doi:10.9767/bcrec.14.1.3320.182-188)Permalink/DOI: https://doi.org/10.9767/bcrec.14.1.3320.182-188 

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