Optimum Supercritical Fluid Extraction Conditions Research Articles

Optimizing the Supercritical Carbon Dioxide Extraction of Hibiscus Flower Essential Oil using Response Surface Analysis

The development of Supercritical Fluid Extraction (SFE) has opened the door to the harvesting of plants for a wide range of chemical compounds. This study distilled essential oil from hibiscus flowers utilizing the supercritical CO2 method. Different extraction parameters, including pressure (100-300 bar) and temperature (300-350 K), were studied to visualize how they affected oil recovery. Response surface analysis was used to fine-tune the extraction process. The chemical composition of the recovered oil was analyzed by Gas Chromatography-Mass Spectrometry (GC-MS). According to the findings, 13.11% per 80 g of dry flowers is the ideal oil extracted from Hibiscus flowers, using SFE at 200 bar pressure and 325 K extraction temperature. Six compounds were provisionally identified in the extracted oil from hibiscus flowers under optimum SFE conditions.

Supercritical CO2 Extraction of High-Added Value Compounds from Chlorella vulgaris: Experimental Design, Modelling and Optimization.

Microalgae are well-known for their high-added value compounds and their recovery is currently of great interest. The aim of this work is the recovery of such components from Chlorella vulgaris through supercritical fluid extraction (SFE) with CO2. The effect of the extraction temperature (40–60 °C), pressure (110–250 bar), and solvent flow rate (20–40 g/min) was tested on yield, the extract’s antioxidant activity, and the phenolic, chlorophyll and carotenoid content. Thus, data analysis indicated that the yield was mainly affected by temperature, carotenoids by pressure, while the extract’s phenolics and antioxidant activity were affected by the synergy of temperature and pressure. Moreover, SFE’s kinetic study was performed and experimental data were correlated using Sovová’s mass transfer-based model. SFE optimization (60 °C, 250 bar, 40 g/min) led to 3.37% w/w yield, 44.35 mgextr/mgDPPH antioxidant activity (IC50), 18.29 mgGA/gextr total phenolic content, 35.55, 21.14 and 10.00 mg/gextr total chlorophyll, carotenoid and selected carotenoid content (astaxanthin, lutein and β-carotene), respectively. A comparison of SFE with conventional aq. ethanol (90% v/v) extraction proved SFE’s superiority regarding extraction duration, carotenoids, antioxidant activity and organoleptic characteristics of color and odor despite the lower yield. Finally, cosolvent addition (ethanol 10% w/w) at optimum SFE conditions improved the extract’s antioxidant activity (19.46%) as well as yield (101.81%).

A comparative study of supercritical fluid extraction and accelerated solvent extraction of lipophilic compounds from lignocellulosic biomass

The Box-Behnken experimental design technique investigated a comparative study of supercritical fluid extraction (SFE) and accelerated solvent extraction (ASE) of lipophilic compounds from pinewood sawdust. A response surface methodology was used to examine the effect of independent parameters and optimize the extraction yield of lipophilic compounds. The results showed that the increase in extraction temperature used for ASE positively influenced the yield of lipophilic compounds, whereas an increase in the flow rate of the cosolvent at temperature 50 °C, and pressure of 300 bar increased the yield achieved by SFE. The experimental data's quadratic polynomial models gave a coefficient of determination (R2) of 0.87 and 0.80 for ASE and SFE, respectively. The optimum conditions of ASE were temperature (160 °C), static time (12.5 mins), and static cycle (1), which resulted in a maximum yield of 4.2%. The optimum SFE conditions were temperature (50 °C), pressure (300 bar), carbon dioxide (CO2) flow rate (3.2 ml/min), and a 2 ml/min cosolvent flow rate that yielded 2.5% lipophilic compounds. ASE yielded higher extraction efficiency than SFE. Fourier transform infra-red (FTIR) spectroscopy and thermal analyses TGA/DSC evaluated the ultimate analyses of the lipophilic extracts. The FTIR results confirmed the presence of aliphatic groups, hydroxyl groups, and carboxyl groups. The thermal analysis showed that the degradation temperature of the lipophilic compounds occurred between 250 and 450 °C. Thereafter, Pyrolysis-Gas Chromatography Mass Spectrometry (Py-GC/MS) was used to identify the lipophilic compounds, which showed that the extracts were rich in fatty acids and terpenes.

Response Surface Methodology for Optimization of Supercritical Fluid Extraction of Orange Peel Essential Oil

Background: Orange peel essential oils were obtained using supercritical fluid extraction. This method is an important high scaling extraction method used for the extraction of plant and animal extracts. Objectives: The aim of this study was the optimization of the extraction of the orange peel essential oil. Methods: The experimental parameters of Supercritical Fluid Extraction (SFE) such as temperature, pressure, and extraction time, and modifier volume were optimized using a central composite design after a 24-1 fractional factorial design. Orange peels were collected from ripe orange and were washed, air dried, and milled. Then, a Suprex MPS/225 system in the SFE mode with a maximal operating pressure of 395 bars was used for essential oil extraction. Moreover, GC-MS and GC-FID were used for the identification and determination of oil compounds, respectively. Results: Eight compounds have been identified based on their retention indices and mass spectra. According to the results, α-pinene, β-pinene, myrcene, d-limonene, terpinolene, C8-aldehyde, citronellol, and linalool were identified in orange peel essential oil. The optimum SFE conditions were obtained at a pressure of 347.07 atm, temperature of 55° C, extraction time of 30.16 min, and ethanol volume of 147.05 µL. Moreover, extraction yields based on SFE varied in the range of 0.04% to 1.18% (w/w). Conclusion: The Results showed supercritical fluid technology as the best alternative technique for the extraction of pure and high-quality essential oil from orange peel. It is a green method and does not have any environmental impact.

Artocarpus altilis extracts as a food-borne pathogen and oxidation inhibitors: RSM, COSMO RS, and molecular docking approaches

Lipid oxidation and microbial contamination are the major factors contributing to food deterioration. Food additives like antioxidants and antibacterials can prevent food spoilage by delaying oxidation and preventing the growth of bacteria. Artocarpus altilis leaves exhibited biological properties that suggested its use as a new source of natural antioxidant and antimicrobial. Supercritical fluid extraction (SFE) was used to optimize the extraction of bioactive compounds from the leaves using response surface methodology (yield and antioxidant activity). The optimum SFE conditions were 50.5 °C temperature, 3784 psi pressure and 52 min extraction time. Verification test results (Tukey’s test) showed that no significant difference between the expected and experimental DPPH activity and yield value (99%) were found. Gas-chromatography –mass spectrometry (GC-MS) analysis revealed three major bioactive compounds existed in A. altilis extract. The extract demonstrated antioxidant and antibacterial properties with 2,3-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity, ferric reducing ability of plasma (FRAP), hydroxyl radical scavenging activity, tyrosinase mushrrom inhibition of 41.5%, 8.15 ± 1.31 (µg of ascorbic acid equivalents), 32%, 37% and inhibition zone diameter of 0.766 ± 0.06 cm (B. cereus) and 1.27 ± 0.12 cm (E. coli). Conductor like screening model for real solvents (COSMO RS) was performed to explain the extraction mechanism of the major bioactive compounds during SFE. Molecular electrostatic potential (MEP) shows the probability site of nucleophilic and electrophilic attack during bacterial inhibition. Based on molecular docking study, non-covalent interactions are the main interaction occurring between the major bioactive compounds and bacteria (antibacterial inhibition).

Application of response surface methodology for the optimization of supercritical fluid extraction of essential oil from pomegranate (Punica granatum L.) peel.

Essential oils and volatile components of pomegranate (Punica granatum L.) peel of the Malas variety from Meybod, Iran, were extracted using supercritical fluid extraction (SFE) and hydro-distillation methods. The experimental parameters of SFE that is pressure, temperature, extraction time, and modifier (methanol) volume were optimized using a central composite design after a (24-1) fractional factorial design. Detailed chemical composition of the essential oils and volatile components obtained by hydro-distillation and optimum condition of the supercritical CO2 extraction were analyzed by GC-MS, and seventy-three and forty-six compounds were identified according to their retention indices and mass spectra, respectively. The optimum SFE conditions were 350 atm pressure, 55°C temperature, 30min extraction time, and 150 µL methanol. Results showed that oleic acid, palmitic acid and (-)-Borneol were major compounds in both extracts. The optimum extraction yield was 1.18 % (w/w) for SFE and 0.21 % (v/w) for hydro-distillation.

Optimization of Focused Ultrasound Extraction (FUSE) and Supercritical Fluid Extraction (SFE) of Citrus Peel Volatile Oils and Antioxidants

In order to evaluate the use of citrus peel as a potential source of volatile oils and antioxidants in food industry, supercritical fluid extraction (SFE) and focused ultrasound extraction (FUSE) techniques have been thoroughly studied. Based on experimental designs and considering the extraction of monoterpenes among the volatile oils, the total phenol content, and the antioxidants, the most adequate extraction conditions have been defined for lemon and then applied to other citrus. The optimum SFE conditions for volatile oils and antioxidants were the following: pressure, 100 and 170 bar; temperature, 35 °C for both; flow, 1 mL/min in both cases; EtOH%, 0 and 40 %, respectively. FUSE extraction of the volatile oils was carried out with cyclohexane and the antioxidants with ethanol. The optimum instrumental conditions were roughly the same (extraction time 5 min, cycles 5 s−1, and amplitude 30 % in both cases, and 10 and 15 mL, respectively, in the case of solvent volumes). Based on successive extractions, FUSE revealed a more efficient technique owing to the solvent features. Finally, a stability test of the content of aromas and antioxidant capacity was carried out and aromas were stable stored at 4 °C for 6 weeks and the antioxidant capacity, in the same conditions, for 13 weeks.

Supercritical Fluid Extraction of Phenolic Compounds and Antioxidants from Grape (Vitis labrusca B.) Seeds

Supercritical fluid extraction (SFE) technique was applied and optimized for temperature, CO₂ pressure and ethanol (modifier) concentration using orthogonal array design and response surface methodology for the extract yield, total phenols and antioxidants from grape (Vitis labrusca B.) seeds. Effects of extraction temperature and pressure were found to be significant for all these response variables in SFE process. Optimum SFE conditions (44 ~ 46 °C temperature and 153 ~ 161 bar CO₂ pressure) along with ethanol (<7 %) as modifier, for the maximum predicted values of extract yield (12.09 %), total phenols (2.41 mg GAE/ml) and antioxidants (7.08 mg AAE/ml), were used to obtain extracts from grape seeds. The predicted values matched well with the experimental values (12.32 % extract yield, 2.45 mg GAE/ml total phenols and 7.08 mg AAE/ml antioxidants) obtained at optimum SFE conditions. The antiradical assay showed that SFE extracts of grape seeds can scavenge more than 85 % of 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radicals. The grape seeds extracts were also analyzed for hydroxybenzoic acids which included gallic acid (1.21 ~ 3.84 μg/ml), protocatechuic acid (3.57 ~ 11.78 μg/ml) and p-hydroxybenzoic acid (206.72 ~ 688.18 μg/ml).

Central Composite Design for the Optimization of Supercritical Carbon Dioxide Fluid Extraction of Fatty Acids from Borago Officinalis L. Flower

In the present study, fatty acids and essential oils of the flower of borage (Borago officinalis L.) were obtained by supercritical carbon dioxide fluid extraction under different conditions. The extracts obtained were compared to oils of borage flower oil isolated by hydrodistillation. The obtained oils were analyzed by gas chromatography mass spectrometry. The compounds were identified according to their retention indices and mass spectra. The experimental parameters of supercritical fluid extraction (SFE) were optimized using a central composite design after a full factorial experimental design. Extraction yields based on SFE varied in the range of 0.02% to 1.96% (w/w), and the oil yield based on the hydrodistillation was 0.05% (v/w). The optimum conditions of SFE were obtained at a pressure of 350 atm, a temperature of 65 °C, a methanol modifier volume of 100 μL, and static and dynamic extraction time of 10 min. Main components of the extracts under optimum SFE conditions were palmitic acid, linoleic acid, γ-linolenic acid, and oleic acid. The results indicated that by using the suitable extraction conditions, SFE is more effective than the conventional hydrodistillation method in the extraction of fatty acids and the preservation of its quality. SFE is a good technique for the extraction of oils from plants. The extraction yields by SFE are more than the conventional method. SFE is used on a large scale for production of essential oils and pharmaceutical products from plants.

Selective extraction of astaxanthin from crustaceans by use of supercritical carbon dioxide

An on-line supercritical fluid extraction (SFE) system coupled to a continuous flow manifold including a UV detector was used as a screening system to extract astaxanthin from crayfish, which was found to be the major carotenoid present in the samples. This compound constitutes the principal additive used to dye salmon flesh. The flow manifold was used to confirm the presence of astaxanthin in the crustacean samples. Also, an HPLC/UV–vis method was used to ascertain that this compound was the major carotenoid extracted under the optimum SFE conditions employed. The influence of SFE operating variables such as pressure, temperature, equilibration time, extraction time, trap temperature, and volume of CO2 modifier was examined in order to maximize the efficiency of analyte extraction. The use of supercritical CO2 enables the expeditious, selective, quantitative extraction of astaxanthin from crustaceans.

Selective extraction of astaxanthin from crustaceans by use of supercritical carbon dioxide

An on-line supercritical fluid extraction (SFE) system coupled to a continuous flow manifold including a UV detector was used as a screening system to extract astaxanthin from crayfish, which was found to be the major carotenoid present in the samples. This compound constitutes the principal additive used to dye salmon flesh. The flow manifold was used to confirm the presence of astaxanthin in the crustacean samples. Also, an HPLC/UV–vis method was used to ascertain that this compound was the major carotenoid extracted under the optimum SFE conditions employed. The influence of SFE operating variables such as pressure, temperature, equilibration time, extraction time, trap temperature, and volume of CO2 modifier was examined in order to maximize the efficiency of analyte extraction. The use of supercritical CO2 enables the expeditious, selective, quantitative extraction of astaxanthin from crustaceans.

Enhanced Detection of Nitroaromatic Explosive Vapors Combining Solid-Phase Extraction-Air Sampling, Supercritical Fluid Extraction, and Large-Volume Injection-GC

A complete method for sampling and analyzing of energetic compounds in the atmosphere is described. The method consists of the hyphenation of several techniques: active air sampling using a solid-phase extraction cartridge to collect the analytes, extraction of the sorbed analytes by toluene/methyl tert-butyl ether modified supercritical fluid extraction (SFE), and analysis of the extract by large-volume injection GC-nitrogen/phosphorus detection. The GC system is equipped with a loop-type injection interface with an early solvent vapor exit, a utilizing concurrent solvent evaporation technique. Chemometric approaches, based on a Plackett-Burman screening design and a central composite design for response surface modeling, were used to determine the optimum SFE conditions. The relative standard deviations of the optimized method were determined to be 4.3 to 7.7%, giving raise to method detection limits ranging from 0.06 to 0.36 ng in the sampling cartridge, equivalent to 6.2-36.4 pg/L in the atmosphere, standard sampling volume 10 L. The analytical method was applied to characterize headspace composition above military grade trinitrotoluene (TNT). Results confirm that 2,4-dinitrotoluene (DNT) and 1,3-dinitrobenzene (DNB) constitute the largest vapor flux, but TNT, 2,6-DNT, and trinitrobenzene TNB were also consistently detected in all the samples.

Development of a quantitative analysis method for polypropylene additives using on-line SFE/SFC

A procedure is described for the quantitative analysis of (Irganox 1076, Irganox 1010 and Tinuvin 327) in polypropylene matrices using on-line SFE/SFC. The effects of pressure, extraction time, type of matrix (particle or film) and matrix parameters (particle size, film thickness, sample weight) are studied in order to optimize supercritical fluid extractions. The collection efficiency is determined from the recovery of known concentrations of compounds. About 30% of extracts are lost during collection. Calibration curves for polymer samples are established from ground polymer (particle size 100 μm < d < 160 μm) and polymer film (30 μm thickness) under the optimum supercritical fluid extraction conditions. The three additives are incorporated together into polymer at concentrations ranging from 0.04% to 0.6%. Very poor recoveries are obtained from ground samples, but we observed very good recoveries from films (45-70% depending on the additive) and calibration curves were established for the different antioxidants.

Optimization of SFE Conditions for the Removal of Diesel Fuel

Successful strategies for quantitative removal of contaminants such as diesel fuel from soils by supercritical fluid extraction (SFE) require the development of extraction profiles using an inert matrix. We investigated the optimum SFE conditions for quantitative removal of diesel fuel with supercritical carbon dioxide (CO2) from spiked samples of Celite®. The range of pressure tested was 200 to 500 atm and the temperature range was 50 to 70°C. The greatest recovery of diesel fuel was for the conditions of 300 or 350 atm and 50°C for 30 minutes. Recovery was determined by total petroleum hydrocarbon (TPH) analysis by gas chromatography/flame ionization detection (GC/FID) and by weight difference. With losses due to sample handling accounted for, more than 95% recovery was observed at these conditions. The moderate temperatures and pressures required for SFE with CO2 along with rapid recoveries promise an efficient technology for soil remediation.

Analysis of poly(vinyl chloride) additives by supercritical fluid extraction and gas chromatography

The use of supercritical fluid extraction (SFE) is growing, with an expanding range of applications in many different fields as a consequence of its advantages compared with traditional extraction methods. In order to develop an analytical method to determine dibutyl phthalate (DBP) and dioctyl phthalate (DOP) traces (<20 ppm) in flexible poly(vinyl chloride) (PVC) formulations, a maximum efficiency in the extractive process and an adequate separative system are needed to avoid interferences between these two plasticizers and other additives that could be present at high concentrations in flexible PVC formulations. In order to determine the optimum SFE conditions, the extraction time, temperature and pressure were controlled. The separation and quantitation of individual components in the PVC extracts were carried out off-line by using a semicapillary column in gas chromatography (GC). Samples with different DOP content (41.18%, 33.33% and 23.08%) and DBP content (41.18%), as well as samples with both plasticizers (20.59% DOP and 20.59% DBP) were prepared. Some other samples were also prepared to study detection limits for these two PVC additives. Recoveries and reproducibilities were studied in every sample. Finally, this method was compared with Soxhlet liquid extraction. Determination by gravimetric analysis of the total extracted material was found to be particularly suitable for PVC. This study demonstrates the potential of SFE to shorten extraction times with similar or even better extraction efficiencies compared with traditional liquid methods.

Supercritical CO2Fluid Extraction of Imazaquin From Soil

Feasibility of supercritical CO2fluid extraction of imazaquin from spiked soil (3.21 μmol kg-1) as an alternative to a conventional extraction method was investigated. The supercritical fluid extraction method involved single-step extraction of herbicide from soil with no further sample cleanup procedures. Extraction parameters were optimized for maximum herbicide recovery. Adding water as a modifier to air-dried soil significantly improved herbicide recovery. Extracting a 1-g soil sample with supercritical CO2at 0.80 g ml-1density and 3 ml min-1flow rate, 80 C extraction temperature, 6 min static extraction followed by 25 min dynamic extraction, and analyte trap temperature of 40 C was optimum for maximum herbicide recovery. When optimum supercritical fluid extraction conditions were used, imazaquin recovery from three texturally different soils ranged from 55 to 64%, which was comparable to a conventional extraction method (63%). The supercritical fluid extraction method consumed 4 ml methanol and 75 ml supercritical CO2and took approximately 1 h for sample extraction.

Isolation of peppermint oil using supercritical co2 extraction

AbstractPeppermint leaf oil was isolated by a supercritical fluid extraction (SFE) using CO2 in which the extraction was followed by a two‐stage fractional separation. Chemical analysis revealed that oils extracted under different SFE conditions possessed a widely different percentage composition. The percentage of co‐extracted cuticular waxes varied too. Oil obtained by hydrodistillation was also compared with the extracted oils. Although practically the same compounds were present in the hydrodistilled oil, its composition was similar to SFE oil extracted under non‐optimized conditions. Qualitative aroma tests showed that the oil obtained at optimum SFE conditions (p = 90 bar, T = 50°C) had a fragrance that better resembled that of the peppermint leaves used for the extraction of the oils.

Analysis of poly(vinyl chloride) additives by supercritical fluid extraction and supercritical fluid chromatography

The use of supercritical fluid extraction (SFE) as an alternative to liquid extraction was investigated. Supercritical CO2 was used to extract additives in poly(vinyl chloride)(PVC). The extraction time, temperature and pressure were varied in order to determine the optimum SFE conditions. The effects of the particle size of the sample and the addition of methanol to the extraction fluid were also investigated. The separation and quantification of individual components in the PVC extracts were carried out off-line using packed column supercritical fluid chromatography (PSFC). This technique combined good resolution, rapid analysis times and linear calibrations over a wide range of additive concentrations. By using SFE, 29.2% m/m of the sample was extracted of which 66.7% m/m was diisooctyl phthalate (DIOP). This compared with the existing liquid extraction method by which 30% m/m of the sample was extracted of which 67% was DIOP. The total extractions varied by 0.9% relative standard deviation (RSD) and the DIOP content varied by 1.2% RSD.