Solid-liquid Extraction System Research Articles

Bioherbicide from Azadirachta indica Seed Waste: Exploitation, Efficient Extraction of Neem Oil and Allelopathic Effect on Senna occidentalis

Bioherbicides are an alternative to minimize the damage caused to the environment using agrochemicals. This study had the objective of extracting neem oil from ripe waste fruits that Azadirachta indica A. Juss and optimizing the process using solvents (or a mixture of solvents) with different polarities. Then, through a solid-liquid extraction system (Soxhlet), the solvents hexane, methanol/hexane (1:1), ethanol, and hexane/ethanol (1:1) were used to determine the process with the highest yield and most efficiency. The physicochemical parameters of the extracted oil (density, acidity value, iodine value, saponification value, esters value, and molecular weight) and the % of free fatty acids were determined. In addition, the allelopathic properties of the oil (0%, 2%, 3%, and 4% m/v) on septic weed Senna occidentalis seeds were evaluated, analyzing their growth and development parameters (germination, germination speed, hypocotyl, and radicle length). Hexane was the most efficient (4 h) in neem oil extraction, with the highest yield (43%). It also provided a better oleic and linoleic acid content (41.3% and 18.6%), similar to ethanol extraction (41.1% and 20.22%). Moreover, the allelopathic properties were more prominent for the oils extracted with hexane and hexane/ethanol. This optimized process provides an efficient alternative to obtain a natural herbicidal potential for strategically controlling harmful plants.

Soybean oil extraction with ethanol from multiple-batch assays to reproduce a continuous, countercurrent, and multistage equipment

The replacement of toxic organic solvents from fossil sources by nontoxic ones from biorenewable origin in large-scale processes has been a frequent search. Although ethanol has been currently investigated as a hexane-substitute for vegetable oils extraction, most studies are conducted on laboratorial scale and in batch assays. Initial parameters of a continuous and countercurrent extractor that indicates the technical possibility of a large-scale operation are still scarce. Here, a continuous extractor composed of fixed bed columns connected in series (resembling the so-called simulated moving bed extractor) for soybean oil extraction with anhydrous ethanol was experimentally reproduced by a multiple-batch solid-liquid extraction system. After a 5-stage extraction, the residual oil in the solid phase was 0.17% with 99.2% extraction yield, confirming that ethanol was capable to exhaust the solid matrix with a reasonable extraction yield. Although the minimum solvent-to-feed ratio (S/F) for ethanol (S/F = 2.62/1) was higher than that for hexane (S/F = 0.36/1), benefits in relation to food safety, reduction in handling danger, and less environmental impact reinforce ethanol as a safe and promising solvent for the extraction of vegetable oils in a continuous equipment.

Preparation of polysulfone-graft-monoazabenzo-15-crown-5 ether porous membrane for lithium isotope separation

A novel polysulfone-graft-monoazabenzo-15-crown-5 ether (PSF-g-BN15C5) polymer was prepared via nucleophilic substitution reaction and characterized by FT-IR, 1H NMR, TGA, and XPS. The non-induced phase separation was employed to fabricate PSF-g-BN15C5 porous membrane with sponge-like structure for lithium isotope separation. The effects of lithium salt, temperature and immobilization amount of crown ether on distribution coefficient and separation factor were explored. Results showed that a maximum separation factor obtained from the solid–liquid extraction system of H2O-LiI/PSF-g-BN15C5 was up to 1.049 ± 0.002. Furthermore, the light isotope 6Li was enriched in the membrane phase owing to the stronger bonding environment.

Simulation and process design of continuous countercurrent ethanolic extraction of rice bran oil

The overwhelming majority of all vegetable oils is extracted using solvent extraction, and the most widely used solvent is hexane. However, the use of ethanol has attractive advantages, including low toxicity, good operational security, as well as being obtained from a biorenewable source. In this study, a multiple-batch solid-liquid extraction system has been successfully employed to simulate continuous countercurrent ethanolic extraction of rice bran oil. Results showed that the extraction process using ethanol as solvent is feasible and facilitated by increases in temperature. The number of equilibrium stages required for rice bran oil extraction was theoretically determined, and it was shown that in the extraction process using hexane the number of ideal stages is lower than the number required when ethanol is used as solvent. Furthermore, a mathematical expression for determining the minimum flow of solvent depending on the equilibrium relationship between the extract and raffinate phases has been developed and implemented for both solvents. Given the potential fire hazard and harmful emissions risks of using hexane as solvent, extraction with ethanol showed to be a promising alternative to conventional extraction, completely exhausting the solid matrix with only five stages.

An optimization based algorithm for solving design problems of counter-current multistage batch solid–liquid extractors for complex systems: Application to vanilla extract

Solid–liquid extraction is one of the aged unit operations in chemical engineering. However the process design models, universally included in textbooks, continue considering infinite dilution of extractable material and single component solvent. Extraction processes of bioactive compounds with composite solvents (ethanol–water) from plants or foods products require a better understanding of equilibrium between phases of bioactive compounds and their role in the process design. Then, a general mathematical model of counter-current ideal multi-stages batch solid–liquid extractors was developed. The model considers composite solvents and the two equilibrium relations required for the total description of a solid–liquid extraction system. An optimization based algorithm was proposed for solving the design problems. Experimental equilibrium relations were obtained for vanilla–ethanol–water system and used as example of model application. Additionally, the prediction of a particular component (vanillin) concentration in extract was included and experimentally validated.

Preparation and Characterization of Polysulfone-graft-4′-aminobenzo-15-crown-5-ether for Lithium Isotope Separation

A novel polymer polysulfone (PSF)-graft-4′-aminobenzo-15-crown-5-ether (AB15C5) (PSF-g-AB15C5) for lithium isotope separation was prepared from PSF and AB15C5 as starting materials via nucleophilic substitution reaction. The chemical structure and properties of PSF-g-AB15C5 polymers were characterized by FT-IR, 1H NMR, XPS, and TGA. The polymers obtained were used for lithium isotope separation by solid–liquid extraction. The effects of the immobilization amount of crown ether grafting on PSF, the type of counteranion of lithium salt, and the kind of solvent on the single stage separation factor were explored. Results showed that the single stage separation factor was only 1.002 ± 0.002 for AB15C5 in the traditional liquid–liquid extraction system of H2O–LiCl/CHCl3–AB15C5, whereas the single stage separation factor increased from 1.003 ± 0.001 to 1.015 ± 0.002 with the increase of the immobilization amount of crown ether from 0.23 to 0.79 mmol g–1 on PSF-g-AB15C5 polymers in the solid–liquid extraction system of CH3OH–LiCl/PSF-g-AB15C5 polymers. The order of the single stage separation factor obtained in different lithium salts was LiI > LiBr > LiClO4 > LiCl. Further, the maximum value of single stage separation factor was 1.031 ± 0.002 for the extraction system of CH3NO2–LiCl/PSF-g-AB15C5 polymers. Moreover, 6Li and 7Li were enriched in the polymer phase and the solution phase, respectively.

Studies on Temperature Dependent Ionic Liquid Solid-Liquid Extraction Behavior of Rare Earth

Temperature dependent solid-liquid extraction behavior of eight rare earth elements (REs) was investigated using N-butyl pyridinium hexafluorophosphate ([BPPF6) as an ionic liquid solvent and 8-hydroxyquinoline (HQ) as an extractant at 80 °C. Parameters including the amount of [BPPF6, HQ concentration, extraction time, extraction temperature and pH were investigated and optimized. The extracted species was neutral REQ3 in the RE3+-[BPPF6-HQ solid-liquid extraction system. The extraction percentage of RE3+ could be higher than 99%. The recovery of RE3+ extracted into [BPPF6 can be achieved using the mixture of hydrazine hydrate and ethylenediamine tetraacetic acid as stripping agents. The extraction equilibrium constants and the pH1/2 values of eight REs and their separation factors between adjacent rare earths were estimated and comparatively studied. REs were extracted into solid ionic liquid phase with smaller volume and concentrated to some extent. Furthermore the temperature dependent solid-liquid extraction allows to recover [BPPF6 after the extraction procedures. These results indicate that the proposed procedure can be used for the preconcentration and separation of REs using [BPPF6 with high melting point.

Modelling for Extraction of Major Phytochemical Components from Eurycoma longifolia

A mass transfer model of major phytochemical components from Eurycoma longifolia was developed in order to describe the solid-liquid extraction process. The yield of the extraction normally depends on the operating parameters such as solvent to raw material ratio, extraction time, temperature and agitation speed. In this study, the model was developed taking into account the two-way mass transfer of solute into liquid phase and the solvent into solid system. The influence of processing variables such as extraction temperature, solvent to raw material ratio and agitation speed was simulated by the model. Several assumptions were made in the theoretical approach to solve the simulation algorithm in order to predict the performance of the solid-liquid extraction system. From the study, it can be concluded that when the extraction temperature was increased, the yield of extraction also increased and this has reduced the extraction time. The best agitation speed was found to be at 400 rpm.

Production and separation of Astatine Radionuclides: Some new addition to Astatine Chemistry

For the first time no-carrier-added (nca) 209,210At radionuclides were produced by heavy ion ( 7Li) activation from 4 mg/cm 2 lead nitrate target. Astatine was separated from the bulk target by three different approaches. Nca astatine radionuclide was selectively partitioned in the (i) polymer rich phase of an aqueous biphasic system consisting of polyethylene glycol (PEG) 4000 (50% w/w) and 2 M Na 2SO 4 solution (ii) aqueous phase of a liquid liquid extraction system being comprised of a liquid cation exchanger, HDEHP (di-2-ethylhexyl phosphoric acid) (0.5%) and liquor ammonia (iii) liquid phase of a solid liquid extraction system of cation exchange resin Dowex-50 and 10 −6 M HCl. Very high separation factors have been achieved in all the three methods.

Application of centrifugal force to the extraction and separation of parasorboside and gerberin from Gerbera hybrida.

A method for the separation of parasorboside and gerberin from the ornamental plant Gerbera hybrida (Asteraceae) has been developed. The two closely related glucosides were extracted using an Extrachrom instrument, a prototype multi-functional separation tool equipped with an extraction chamber. The rotation planar extraction procedure was compared with that of a medium pressure solid-liquid extraction system. The resulting extracts were pre-purified using rotation planar chromatography and the results compared with those obtained using medium pressure liquid chromatography with silica gel as the stationary phase and a mobile phase of methanol:ethyl acetate:tetrahydrofuran at selectivity point Ps = 111 with 1% formic acid as modifier. The title compounds were isolated from the purified extracts by TLC and their structures confirmed by 1H- and 13C-NMR spectroscopy.

Adsorption of Zr4+, Hf4+, Rf4+ and Po4+ diketonate complexes on hydrophobized glass surface

Studies of the complexes of the title ions with α and β diketonate ligands were performed with the aim of verifying the influence of relativistic effects upon the coordination number of rutherfordium. Since the diketonate complexes are volatile, we developed a new solid-liquid extraction system based on the adsorption of neutral complexes on hydrophobized glass surfaces. This system was applied to the studies of complexation of the short-lived isotopes Zr4+, Hf4+, Po4+ and Rf4+. The procedure including collection of radioactivity, adsorption of complexes and preparation of the α-source, took roughly 50–60 seconds to complete. The obtained results show that studies of adsorption on hydrophobized glass surface may provide important experimental data on the formation of chelate complexes with short-lived radionuclides.

Protein refolding by reversed micelles utilizing solid‐liquid extraction technique

This article reports that a reversed micellar solution is useful for refolding proteins directly from a solid source. The solubilization of denatured RNase A, which had been prepared by reprecipitation from the denaturant protein solution, into reversed micelles formulated with sodium di-2-ethylhexyl sulfosuccinate (AOT) has been investigated by a solid–liquid extraction system. This method is an alternative to the ordinary protein extraction in reversed micelles based on the liquid–liquid extraction. The solid–liquid extraction method was found to facilitate the solubilization of denatured proteins more efficiently in the reversed micellar media than the ordinary phase transfer method of liquid extraction. The refolding of denatured RNase A entrapped in reversed micelles was attained by adding a redox reagent (reduced and oxidized glutathion). Enzymatic activity of RNase A was gradually recovered with time in the reversed micelles. The denatured RNase A was completely refolded within 30 h. In addition, the efficiency of protein refolding was enhanced when reversed micelles were applied to denatured RNase A containing a higher protein concentration that, in the case of aqueous media, would lead to protein aggregation. The solid–liquid extraction technique using reversed micelles affords better scale-up advantages in the direct refolding process of insoluble protein aggregates. ©1998 John Wiley & Sons, Inc. Biotechnol Bioeng 57: 620-623, 1998.

Protein refolding by reversed micelles utilizing solid-liquid extraction technique

This article reports that a reversed micellar solution is useful for refolding proteins directly from a solid source. The solubilization of denatured RNase A, which had been prepared by reprecipitation from the denaturant protein solution, into reversed micelles formulated with sodium di-2-ethylhexyl sulfosuccinate (AOT) has been investigated by a solid-liquid extraction system. This method is an alternative to the ordinary protein extraction in reversed micelles based on the liquid-liquid extraction. The solid-liquid extraction method was found to facilitate the solubilization of denatured proteins more efficiently in the reversed micellar media than the ordinary phase transfer method of liquid extraction. The refolding of denatured RNase A entrapped in reversed micelles was attained by adding a redox reagent (reduced and oxidized glutathion). Enzymatic activity of RNase A was gradually recovered with time in the reversed micelles. The denatured RNase A was completely refolded within 30 h. In addition, the efficiency of protein refolding was enhanced when reversed micelles were applied to denatured RNase A containing a higher protein concentration that, in the case of aqueous media, would lead to protein aggregation. The solid-liquid extraction technique using reversed micelles affords better scale-up advantages in the direct refolding process of insoluble protein aggregates.

HPLC Measurement of Cyclosporine in Blood Plasma and Urine and Simultaneous Measurement of its Four Metabolites in Blood

Abstract A high performance liquid chromatographic assay has been developed for the estimation of cyclosporine and its four major metabolites in blood and for cyclosporine alone in plasma and urine samples. This assay employs a rapid and very reproducible solid-liquid extraction system. Isocratic chromatographic conditions allow the simultaneous measurement of cyclosporine and its four major metabolites in blood. The method is linear up to 2500 ng/ml and the minimum quantifiable limit for cyclosporine is 30 ng/ml, when 1 ml of sample is analyzed.