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Supercritical fluid extraction and chromatography
18 July 2012,
09:36:47
Publication year:
2012
Source:Journal of Chromatography A, Volume 1250
Colin F. Poole
Source:Journal of Chromatography A, Volume 1250
Colin F. Poole
Theoretical models for supercritical fluid extraction
18 July 2012,
09:36:47
Publication year:
2012
Source:Journal of Chromatography A, Volume 1250
Zhen Huang, Xiao-han Shi, Wei-juan Jiang
For the proper design of supercritical fluid extraction processes, it is essential to have a sound knowledge of the mass transfer mechanism of the extraction process and the appropriate mathematical representation. In this paper, the advances and applications of kinetic models for describing supercritical fluid extraction from various solid matrices have been presented. The theoretical models overviewed here include the hot ball diffusion, broken and intact cell, shrinking core and some relatively simple models. Mathematical representations of these models have been in detail interpreted as well as their assumptions, parameter identifications and application examples. Extraction process of the analyte solute from the solid matrix by means of supercritical fluid includes the dissolution of the analyte from the solid, the analyte diffusion in the matrix and its transport to the bulk supercritical fluid. Mechanisms involved in a mass transfer model are discussed in terms of external mass transfer resistance, internal mass transfer resistance, solute–solid interactions and axial dispersion. The correlations of the external mass transfer coefficient and axial dispersion coefficient with certain dimensionless numbers are also discussed. Among these models, the broken and intact cell model seems to be the most relevant mathematical model as it is able to provide realistic description of the plant material structure for better understanding the mass-transfer kinetics and thus it has been widely employed for modeling supercritical fluid extraction of natural matters.
Source:Journal of Chromatography A, Volume 1250
Zhen Huang, Xiao-han Shi, Wei-juan Jiang
For the proper design of supercritical fluid extraction processes, it is essential to have a sound knowledge of the mass transfer mechanism of the extraction process and the appropriate mathematical representation. In this paper, the advances and applications of kinetic models for describing supercritical fluid extraction from various solid matrices have been presented. The theoretical models overviewed here include the hot ball diffusion, broken and intact cell, shrinking core and some relatively simple models. Mathematical representations of these models have been in detail interpreted as well as their assumptions, parameter identifications and application examples. Extraction process of the analyte solute from the solid matrix by means of supercritical fluid includes the dissolution of the analyte from the solid, the analyte diffusion in the matrix and its transport to the bulk supercritical fluid. Mechanisms involved in a mass transfer model are discussed in terms of external mass transfer resistance, internal mass transfer resistance, solute–solid interactions and axial dispersion. The correlations of the external mass transfer coefficient and axial dispersion coefficient with certain dimensionless numbers are also discussed. Among these models, the broken and intact cell model seems to be the most relevant mathematical model as it is able to provide realistic description of the plant material structure for better understanding the mass-transfer kinetics and thus it has been widely employed for modeling supercritical fluid extraction of natural matters.
Highlights
► Kinetic models for describing supercritical fluid extraction are overviewed. ► Model representations, assumptions, parameter identifications and uses are interpreted. ► Mass transfer resistances, solute–solid interaction and axial dispersion are discussed. ► The broken and intact cell model seems to be more preferably used for scaling-up.Modeling the supercritical fluid extraction of essential oils from plant materials
18 July 2012,
09:36:47
Publication year:
2012
Source:Journal of Chromatography A, Volume 1250
H. Sovová
Different types of mathematical models were applied in the last decade to simulate kinetics of supercritical fluid extraction (SFE) of essential oils from aromatic plants. Compared to the extraction of fatty oils, modeling of extraction of essential oils is more complicated due to their potential fractionation, co-extraction of less soluble compounds, and stronger effect of flow pattern on extraction yield, which is connected with solute adsorption on plant matrix. Fitting the SFE models to experimental extraction curves alone usually does not enable reliable selection among the models. Major progress was made when detailed models for the extraction from glandular structures of plants were developed. As the type of glands is characteristic for plant families, the choice of models for SFE of essential oils is substantially facilitated. As the extracts from aromatic plants contain also cuticular waxes and other less soluble substances, and essential oils themselves are mixtures of substances of different solubility in supercritical carbon dioxide, modeling of extraction of mixtures and their fractionation in time deserves more attention.
Source:Journal of Chromatography A, Volume 1250
H. Sovová
Different types of mathematical models were applied in the last decade to simulate kinetics of supercritical fluid extraction (SFE) of essential oils from aromatic plants. Compared to the extraction of fatty oils, modeling of extraction of essential oils is more complicated due to their potential fractionation, co-extraction of less soluble compounds, and stronger effect of flow pattern on extraction yield, which is connected with solute adsorption on plant matrix. Fitting the SFE models to experimental extraction curves alone usually does not enable reliable selection among the models. Major progress was made when detailed models for the extraction from glandular structures of plants were developed. As the type of glands is characteristic for plant families, the choice of models for SFE of essential oils is substantially facilitated. As the extracts from aromatic plants contain also cuticular waxes and other less soluble substances, and essential oils themselves are mixtures of substances of different solubility in supercritical carbon dioxide, modeling of extraction of mixtures and their fractionation in time deserves more attention.
Highlights
► Many different models were applied to SFE of essential oils in the last decade. ► Major progress is brought by detailed models for SFE from glandular structures. ► The structures characteristic for plant families help to select the proper model. ► Adsorption equilibrium and fractionation of essential oils should be studied. ► More attention should be paid to flow patterns in extraction bed.Isolation of essential oil from different plants and herbs by supercritical fluid extraction
18 July 2012,
09:36:47
Publication year:
2012
Source:Journal of Chromatography A, Volume 1250
Tiziana Fornari, Gonzalo Vicente, Erika Vázquez, Mónica R. García-Risco, Guillermo Reglero
Supercritical fluid extraction (SFE) is an innovative, clean and environmental friendly technology with particular interest for the extraction of essential oil from plants and herbs. Supercritical CO2 is selective, there is no associated waste treatment of a toxic solvent, and extraction times are moderate. Further, supercritical extracts were often recognized of superior quality when compared with those produced by hydro-distillation or liquid–solid extraction. This review provides a comprehensive and updated discussion of the developments and applications of SFE in the isolation of essential oils from plant matrices. SFE is normally performed with pure CO2 or using a cosolvent; fractionation of the extract is commonly accomplished in order to isolate the volatile oil compounds from other co-extracted substances. In this review the effect of pressure, temperature and cosolvent on the extraction and fractionation procedure is discussed. Additionally, a comparison of the extraction yield and composition of the essential oil of several plants and herbs from Lamiaceae family, namely oregano, sage, thyme, rosemary, basil, marjoram and marigold, which were produced in our supercritical pilot-plant device, is presented and discussed.
Source:Journal of Chromatography A, Volume 1250
Tiziana Fornari, Gonzalo Vicente, Erika Vázquez, Mónica R. García-Risco, Guillermo Reglero
Supercritical fluid extraction (SFE) is an innovative, clean and environmental friendly technology with particular interest for the extraction of essential oil from plants and herbs. Supercritical CO2 is selective, there is no associated waste treatment of a toxic solvent, and extraction times are moderate. Further, supercritical extracts were often recognized of superior quality when compared with those produced by hydro-distillation or liquid–solid extraction. This review provides a comprehensive and updated discussion of the developments and applications of SFE in the isolation of essential oils from plant matrices. SFE is normally performed with pure CO2 or using a cosolvent; fractionation of the extract is commonly accomplished in order to isolate the volatile oil compounds from other co-extracted substances. In this review the effect of pressure, temperature and cosolvent on the extraction and fractionation procedure is discussed. Additionally, a comparison of the extraction yield and composition of the essential oil of several plants and herbs from Lamiaceae family, namely oregano, sage, thyme, rosemary, basil, marjoram and marigold, which were produced in our supercritical pilot-plant device, is presented and discussed.
Highlights
► Review of the advances in SFE of essential oils. ► Analysis of the effect of matrix and process conditions. ► Applications toward the extraction of bioactive substances. ► Comparison of the SFE extraction of essential oil from different Lamiaceae plants.Supercritical fluid extraction of free amino acids from broccoli leaves
18 July 2012,
09:36:47
Publication year:
2012
Source:Journal of Chromatography A, Volume 1250
E. Arnáiz, J. Bernal, M.T. Martín, M.J. Nozal, J.L. Bernal, L. Toribio
The extraction of free amino acids (AAs) from broccoli leaves using supercritical fluid extraction (SFE) with CO2 modified with methanol, is presented in this work. The effect of the different variables was studied, showing the percentage of methanol a strong influence on the extraction. The best results in terms of extraction yield were obtained at 250bar, 70°C, 35% methanol as organic modifier, a flow rate of 2mL/min, and 5min and 30min as static and dynamic extraction times, respectively. The extraction yield obtained with the SFE method was comparable to that obtained employing conventional solvent extraction with methanol–water (70:30) and minor than using water, but the relative proportion of the AAs in the extracts was very different. For example, the use of SFE allowed the enrichment in proline and glutamine of the extracts. The selected conditions were applied to obtain SFE extracts of broccoli leaves from different varieties (Naxos, Nubia, Marathon, Parthenon and Viola). The highest levels of AAs were found in the SFE extracts from the Nubia variety.
Source:Journal of Chromatography A, Volume 1250
E. Arnáiz, J. Bernal, M.T. Martín, M.J. Nozal, J.L. Bernal, L. Toribio
The extraction of free amino acids (AAs) from broccoli leaves using supercritical fluid extraction (SFE) with CO2 modified with methanol, is presented in this work. The effect of the different variables was studied, showing the percentage of methanol a strong influence on the extraction. The best results in terms of extraction yield were obtained at 250bar, 70°C, 35% methanol as organic modifier, a flow rate of 2mL/min, and 5min and 30min as static and dynamic extraction times, respectively. The extraction yield obtained with the SFE method was comparable to that obtained employing conventional solvent extraction with methanol–water (70:30) and minor than using water, but the relative proportion of the AAs in the extracts was very different. For example, the use of SFE allowed the enrichment in proline and glutamine of the extracts. The selected conditions were applied to obtain SFE extracts of broccoli leaves from different varieties (Naxos, Nubia, Marathon, Parthenon and Viola). The highest levels of AAs were found in the SFE extracts from the Nubia variety.
Highlights
► SFE was applied to the extraction of free AAs from broccoli leaves. ► The extraction yield was comparable to that obtained employing conventional solvent extraction with methanol–water (70:30). ► SFE extracts have a higher proportion of proline and glutamine. ► The highest amount of essential AAs was found in the Nubia extracts. ► The highest values of total free AAs were obtained in the order Nubia, Naxos and Parthenon.Generalized linear solvation energy model applied to solute partition coefficients in ionic liquid–supercritical carbon dioxide systems
18 July 2012,
09:36:47
Publication year:
2012
Source:Journal of Chromatography A, Volume 1250
Josef Planeta, Pavel Karásek, Barbora Hohnová, Lenka Šťavíková, Michal Roth
Biphasic solvent systems composed of an ionic liquid (IL) and supercritical carbon dioxide (scCO2) have become frequented in synthesis, extractions and electrochemistry. In the design of related applications, information on interphase partitioning of the target organics is essential, and the infinite-dilution partition coefficients of the organic solutes in IL–scCO2 systems can conveniently be obtained by supercritical fluid chromatography. The data base of experimental partition coefficients obtained previously in this laboratory has been employed to test a generalized predictive model for the solute partition coefficients. The model is an amended version of that described before by Hiraga et al. (J. Supercrit. Fluids, in press). Because of difficulty of the problem to be modeled, the model involves several different concepts – linear solvation energy relationships, density-dependent solvent power of scCO2, regular solution theory, and the Flory–Huggins theory of athermal solutions. The model shows a moderate success in correlating the infinite-dilution solute partition coefficients (K-factors) in individual IL–scCO2 systems at varying temperature and pressure. However, larger K-factor data sets involving multiple IL–scCO2 systems appear to be beyond reach of the model, especially when the ILs involved pertain to different cation classes.
Source:Journal of Chromatography A, Volume 1250
Josef Planeta, Pavel Karásek, Barbora Hohnová, Lenka Šťavíková, Michal Roth
Biphasic solvent systems composed of an ionic liquid (IL) and supercritical carbon dioxide (scCO2) have become frequented in synthesis, extractions and electrochemistry. In the design of related applications, information on interphase partitioning of the target organics is essential, and the infinite-dilution partition coefficients of the organic solutes in IL–scCO2 systems can conveniently be obtained by supercritical fluid chromatography. The data base of experimental partition coefficients obtained previously in this laboratory has been employed to test a generalized predictive model for the solute partition coefficients. The model is an amended version of that described before by Hiraga et al. (J. Supercrit. Fluids, in press). Because of difficulty of the problem to be modeled, the model involves several different concepts – linear solvation energy relationships, density-dependent solvent power of scCO2, regular solution theory, and the Flory–Huggins theory of athermal solutions. The model shows a moderate success in correlating the infinite-dilution solute partition coefficients (K-factors) in individual IL–scCO2 systems at varying temperature and pressure. However, larger K-factor data sets involving multiple IL–scCO2 systems appear to be beyond reach of the model, especially when the ILs involved pertain to different cation classes.
Highlights
► Solute partitioning in IL–scCO2 systems was modeled with a predictive correlation. ► Large set of K-factors obtained by SFC provided a stringent test of the model. ► Reproduction of data from single IL–scCO2 systems was relatively successful. ► Simultaneous fit of data from multiple IL–scCO2 systems was difficult to achieve.Determination of carotenoids in microalgae using supercritical fluid extraction and chromatography
18 July 2012,
09:36:47
Publication year:
2012
Source:Journal of Chromatography A, Volume 1250
Victor Abrahamsson, Irene Rodriguez-Meizoso, Charlotta Turner
A method was developed based on supercritical fluid chromatography for quantitative determination of carotenoids in extracts of Scenedesmus sp. By utilizing the low backpressure in supercritical fluid chromatography, a C18 column and a 2-ethyl pyridine column were coupled in series. It was concluded that even minor changes in temperature had a substantial effect on selectivity. A standard mixture of 8 carotenoids and microalgae extracts obtained through supercritical fluid extraction with and without 10% ethanol as a co-solvent were successfully separated. All of the carotenoids were separated within 10min, while the total analysis time was 20min. The method was validated and the carotenoids of microalgae extracts were quantified. Furthermore, the method should be seen as a more rapid and environmentally sustainable alternative to traditional high-performance liquid chromatography methods utilizing organic solvents.
Source:Journal of Chromatography A, Volume 1250
Victor Abrahamsson, Irene Rodriguez-Meizoso, Charlotta Turner
A method was developed based on supercritical fluid chromatography for quantitative determination of carotenoids in extracts of Scenedesmus sp. By utilizing the low backpressure in supercritical fluid chromatography, a C18 column and a 2-ethyl pyridine column were coupled in series. It was concluded that even minor changes in temperature had a substantial effect on selectivity. A standard mixture of 8 carotenoids and microalgae extracts obtained through supercritical fluid extraction with and without 10% ethanol as a co-solvent were successfully separated. All of the carotenoids were separated within 10min, while the total analysis time was 20min. The method was validated and the carotenoids of microalgae extracts were quantified. Furthermore, the method should be seen as a more rapid and environmentally sustainable alternative to traditional high-performance liquid chromatography methods utilizing organic solvents.
Highlights
► Rapid (<10min) separation method for complex carotenoid mixtures. ► “Green and clean” supercritical fluid chromatography (SFC) technology. ► Carotenoids in Scenedesmus sp. were quantified using the validated SFC method. ► Developed SFC method gave low LOD and LOQs as well as high precision.High-throughput phospholipid profiling system based on supercritical fluid extraction–supercritical fluid chromatography/mass spectrometry for dried plasma spot analysis
18 July 2012,
09:36:47
Publication year:
2012
Source:Journal of Chromatography A, Volume 1250
Takato Uchikata, Atsuki Matsubara, Eiichiro Fukusaki, Takeshi Bamba
The dried blood spots (DBS) and dried plasma spots (DPS) analysis is available as a diagnostic tool for genetic diseases and is useful for the screening of biomarkers. In this study, a high-throughput analytical system based on supercritical fluid extraction–supercritical fluid chromatography with tandem mass spectrometry (SFE–SFC/MS/MS) was constructed for phospholipids profiling of DPS. This system is able to simultaneously perform extraction and separation, allowing phospholipids that have common polar head groups to be analyzed. Phospholipids in only 3μl of plasma can be extracted in 5min and analyzed within 15min using this system. A total of 134 phospholipids, including phosphatidylcholine, lysophosphatidylcholine, sphingomyelin, phosphatidylethanolamine and lysophosphatidylethanolamine, were annotated, and 74 phospholipids were analyzed with good repeatability. The SFE–SFC/MS/MS, which is able to perform high-throughput lipid profiling analysis for clinical diagnosis and drug discovery, may also be suitable for the screening of biomarkers.
Source:Journal of Chromatography A, Volume 1250
Takato Uchikata, Atsuki Matsubara, Eiichiro Fukusaki, Takeshi Bamba
The dried blood spots (DBS) and dried plasma spots (DPS) analysis is available as a diagnostic tool for genetic diseases and is useful for the screening of biomarkers. In this study, a high-throughput analytical system based on supercritical fluid extraction–supercritical fluid chromatography with tandem mass spectrometry (SFE–SFC/MS/MS) was constructed for phospholipids profiling of DPS. This system is able to simultaneously perform extraction and separation, allowing phospholipids that have common polar head groups to be analyzed. Phospholipids in only 3μl of plasma can be extracted in 5min and analyzed within 15min using this system. A total of 134 phospholipids, including phosphatidylcholine, lysophosphatidylcholine, sphingomyelin, phosphatidylethanolamine and lysophosphatidylethanolamine, were annotated, and 74 phospholipids were analyzed with good repeatability. The SFE–SFC/MS/MS, which is able to perform high-throughput lipid profiling analysis for clinical diagnosis and drug discovery, may also be suitable for the screening of biomarkers.
Highlights
► We established an SFE–SFC/MS/MS for profiling of phospholipids in DPS. ► Phospholipids in DPS could be analyzed without any pretreatment in 15min. ► A PC HILIC column was used for trapping and separating phospholipids in this system. ► 134 phospholipids (PC, LPC, SM, PE, LPE) from only 3μl plasma could be detected.High-accuracy analysis system for the redox status of coenzyme Q10 by online supercritical fluid extraction–supercritical fluid chromatography/mass spectrometry
18 July 2012,
09:36:47
Publication year:
2012
Source:Journal of Chromatography A, Volume 1250
Atsuki Matsubara, Kazuo Harada, Kazumasa Hirata, Eiichiro Fukusaki, Takeshi Bamba
The accurate profiling of oxidative stress markers is often disturbed by oxidation occurred during sample preparation. In this study, an online supercritical fluid extraction–supercritical fluid chromatography/mass spectrometry system was constructed utilizing supercritical fluid as an efficient solvent for extraction. A higher ratio of the reduced form of coenzyme Q10 (CoQ10) was detected by online extraction, rather than by offline extraction using a conventional organic solvent. The results suggest that the profile of easily oxidized compounds can be acquired with high accuracy using this system because the oxidation of the target compounds during sample preparation can be avoided when using the online extraction.
Source:Journal of Chromatography A, Volume 1250
Atsuki Matsubara, Kazuo Harada, Kazumasa Hirata, Eiichiro Fukusaki, Takeshi Bamba
The accurate profiling of oxidative stress markers is often disturbed by oxidation occurred during sample preparation. In this study, an online supercritical fluid extraction–supercritical fluid chromatography/mass spectrometry system was constructed utilizing supercritical fluid as an efficient solvent for extraction. A higher ratio of the reduced form of coenzyme Q10 (CoQ10) was detected by online extraction, rather than by offline extraction using a conventional organic solvent. The results suggest that the profile of easily oxidized compounds can be acquired with high accuracy using this system because the oxidation of the target compounds during sample preparation can be avoided when using the online extraction.
Highlights
► Analysis of CoQ10 by online supercritical fluid extraction (SFE)–SFC–MS. ► Only 0.05mg of dried photosynthesis bacterium was needed for the analysis. ► A higher ratio of the reduced form of CoQ10 was detected by online SFE. ► Highly accurate analysis of easily oxidized compounds can be performed.Characterization of the subcritical water extraction of Fluoxetine-Hydrochloride
18 July 2012,
09:36:47
Publication year:
2012
Source:Journal of Chromatography A, Volume 1250
Jillian N. Murakami, Kevin B. Thurbide, Gordon Lambertus, Eric Jensen
The characteristics of using Subcritical Water Extraction (SWE) to recover Fluoxetine-Hydrochloride from both standard solutions and the contents of commercial capsule formulations were investigated. Analysis of solutions and extracts was done by HPLC with UV detection at 254nm. Standard solutions of Fluoxetine-Hydrochloride were exposed to a variety of SWE operating conditions, including temperatures from 125 to 275°C and periods ranging from 5 to 30min. Fluoxetine-Hydrochloride could be quantitatively recovered from standard solutions (1.0mg/mL) that were heated up to 175°C for 30min, up to 200°C for 15min, or up to 225°C for 10min. At higher temperatures and/or times, Fluoxetine-Hydrochloride recoveries were generally incomplete and often produced decomposition by-products during the process. By comparison, the concentration of Fluoxetine-Hydrochloride in the standard solution had relatively little effect on recovery. Considering these parameters, an SWE method was developed to extract Fluoxetine-Hydrochloride from the contents of Prozac® capsules. It was found that Fluoxetine-Hydrochloride could be quantitatively extracted from the capsule contents in 8min at a temperature of 200°C using 3.5mL of water as the extraction solvent. Gelatinization of the starch excipient in the capsule contents was also observed to occur temporarily during the capsule extractions, before ultimately disappearing again. The period of this phenomenon was dependent on both temperature and sample size. The results indicate that SWE can be a very useful method for Fluoxetine-Hydrochloride extraction and suggest that it may be interesting to explore other pharmaceuticals using this method as well.
Source:Journal of Chromatography A, Volume 1250
Jillian N. Murakami, Kevin B. Thurbide, Gordon Lambertus, Eric Jensen
The characteristics of using Subcritical Water Extraction (SWE) to recover Fluoxetine-Hydrochloride from both standard solutions and the contents of commercial capsule formulations were investigated. Analysis of solutions and extracts was done by HPLC with UV detection at 254nm. Standard solutions of Fluoxetine-Hydrochloride were exposed to a variety of SWE operating conditions, including temperatures from 125 to 275°C and periods ranging from 5 to 30min. Fluoxetine-Hydrochloride could be quantitatively recovered from standard solutions (1.0mg/mL) that were heated up to 175°C for 30min, up to 200°C for 15min, or up to 225°C for 10min. At higher temperatures and/or times, Fluoxetine-Hydrochloride recoveries were generally incomplete and often produced decomposition by-products during the process. By comparison, the concentration of Fluoxetine-Hydrochloride in the standard solution had relatively little effect on recovery. Considering these parameters, an SWE method was developed to extract Fluoxetine-Hydrochloride from the contents of Prozac® capsules. It was found that Fluoxetine-Hydrochloride could be quantitatively extracted from the capsule contents in 8min at a temperature of 200°C using 3.5mL of water as the extraction solvent. Gelatinization of the starch excipient in the capsule contents was also observed to occur temporarily during the capsule extractions, before ultimately disappearing again. The period of this phenomenon was dependent on both temperature and sample size. The results indicate that SWE can be a very useful method for Fluoxetine-Hydrochloride extraction and suggest that it may be interesting to explore other pharmaceuticals using this method as well.
Highlights
► Stability of a model pharmaceutical, fluoxetine, is probed in subcritical water. ► Remarkable stability in terms of time and temperature are observed. ► Some interference from starch excipient gelatinization is noted and characterized. ► Subcritical water can also extract fluoxetine from Prozac capsules quantitatively. ► Potential for subcritical water extraction as a viable method for pharmaceuticals.Countercurrent flow of supercritical anti-solvent in the production of pure xanthophylls from Nannochloropsis oculata
18 July 2012,
09:36:47
Publication year:
2012
Source:Journal of Chromatography A, Volume 1250
Yueh-Cheng Cho, Yuan-Chuen Wang, Chwen-Jen Shieh, Justin Chun-Te Lin, Chieh-Ming J. Chang, Esther Han
This study examined pilot scaled elution chromatography coupled with supercritical anti-solvent precipitation (using countercurrent flow) in generating zeaxanthin-rich particulates from a micro-algal species. Ultrasonic agitated acetone extract subjected to column fractionation successfully yielded a fraction containing 349.4mg/g of zeaxanthin with a recovery of 85%. Subsequently, supercritical anti-solvent (SAS) precipitation of the column fraction at 150bar and 343K produced submicron-sized particulates with a concentration of 845.5mg/g of zeaxanthin with a recovery of 90%. Experimental results from a two-factor response surface method SAS precipitation indicated that purity, mean size and morphology of the precipitates were significantly affected by the flow type configuration, feed flow rate and injection time.
Source:Journal of Chromatography A, Volume 1250
Yueh-Cheng Cho, Yuan-Chuen Wang, Chwen-Jen Shieh, Justin Chun-Te Lin, Chieh-Ming J. Chang, Esther Han
This study examined pilot scaled elution chromatography coupled with supercritical anti-solvent precipitation (using countercurrent flow) in generating zeaxanthin-rich particulates from a micro-algal species. Ultrasonic agitated acetone extract subjected to column fractionation successfully yielded a fraction containing 349.4mg/g of zeaxanthin with a recovery of 85%. Subsequently, supercritical anti-solvent (SAS) precipitation of the column fraction at 150bar and 343K produced submicron-sized particulates with a concentration of 845.5mg/g of zeaxanthin with a recovery of 90%. Experimental results from a two-factor response surface method SAS precipitation indicated that purity, mean size and morphology of the precipitates were significantly affected by the flow type configuration, feed flow rate and injection time.
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