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Mirjana Minceva - One of the best experts on this subject based on the ideXlab platform.

  • Sequential Centrifugal Partition Chromatography
    Simulated Moving Bed Technology, 2020
    Co-Authors: Alírio E. Rodrigues, Mirjana Minceva, Carla Pereira, Luís S. Pais, Ana M. Ribeiro, António E. Ribeiro, M. Silva, Nuno S. Graça, Josefina Santos
    Abstract:

    This chapter is dedicated to the continuous solid support-free Liquid–Liquid chromatographic process called sequential centrifugal partition Chromatography (sCPC). It starts with a short introduction to the fundamentals and specifics of solid support-free Liquid–Liquid Chromatography. It then shows the usefulness of using a predictive thermodynamic method (conductor-like screening model for real solvents) for screening and selection of biphasic solvent systems (i.e., the mobile and stationary phase). By the end of the chapter the principle of the sCPC, a shortcut method for selection of unit operating parameters, and a mathematical model for the simulation of an sCPC unit operation are presented. Last, the presented methods and concepts are demonstrated with an example that includes the design of an sCPC separation of a binary mixture of components with very similar molecular structure.

  • Operating mode and parameter selection in Liquid-Liquid Chromatography.
    Journal of Chromatography A, 2019
    Co-Authors: Raena Morley, Mirjana Minceva
    Abstract:

    Abstract The presence of a Liquid stationary phase in Liquid–Liquid Chromatography (LLC) allows for high versatility of operation as well as adaptability to different sample types and separation tasks. LLC, also known as countercurrent Chromatography (CCC) or centrifugal partition Chromatography (CPC), offers the user a variety of operating modes, many of which have no direct equivalent in conventional preparative Liquid–solid Chromatography. These operating modes have the potential to greatly improve LLC separation performance compared to the standard “classical” isocratic batch injection mode, and they often require minimal to no addition of equipment to the standard set-up. However, reports of the use of alternative LLC operating modes make up only a fraction of the literature. This is likely due, at least in part, to the lack of clear guidelines and methods for operating mode and parameter selection, leaving alternative process options to be avoided and underutilized. This review seeks to remedy this by providing a thorough overview of the available LLC operating modes, identifying the key characteristics, advantages and disadvantages, and areas of application of each. Additionally, the equations and short-cut models aiding in operating mode and parameter selection are presented and critiqued, and their notation is unified for clarity. By rendering LLC and its alternative operating modes more accessible to current and prospective users, it is hoped to help expand the application of this technology and support the achievement of its full potential.

  • Direct extraction of astaxanthin from the microalgae Haematococcus pluvialis using Liquid–Liquid Chromatography
    RSC Advances, 2019
    Co-Authors: Andreas Bauer, Mirjana Minceva
    Abstract:

    The microalgae Haematococcus pluvialis (H. pluvialis) is used for biotechnological production of the red carotenoid astaxanthin. Astaxanthin synthesis involves the formation of a rigid cell wall that impedes direct astaxanthin extraction into a solvent. During the subsequent downstream processing, the algal broth is harvested by centrifugation, dried and mechanically disrupted; finally, astaxanthin is extracted with supercritical CO2. In this study, an alternative extraction process was established, using a Liquid–Liquid chromatographic column to directly extract astaxanthin from the fermentation broth into a solvent. To achieve this, germination of H. pluvialis cyst cells was initiated, resulting in the release of flagellated zoospores into the fermentation broth. It was shown that astaxanthin could be extracted from the zoospores directly from the algal broth using different solvents; with ethyl acetate, yields reaching 85% were achieved in a shake-flask extraction. Using a Liquid–Liquid chromatographic column, astaxanthin concentrations reaching 500 mg L−1 were obtained, corresponding to eightfold concentration of the astaxanthin content in the fermentation broth. The mechanical cell disruption, drying and extraction with supercritical CO2 in the conventional astaxanthin production can be replaced by a direct astaxanthin extraction process, using a Liquid–Liquid chromatographic column. This allows direct astaxanthin extraction at the site of H. pluvialis production.

  • Influence of temperature on the separation performance in solid support-free Liquid-Liquid Chromatography.
    Journal of Chromatography A, 2019
    Co-Authors: Simon Roehrer, Mirjana Minceva
    Abstract:

    Abstract In a biphasic Liquid system, temperature affects the phase composition, so that a change in temperature can even turn the system into a single-phase system. Furthermore, temperature influences the physical properties of the phases, such as density, viscosity and interfacial tension. In this work, temperature was evaluated as an influencing factor for the separation performance in solid support-free Liquid-Liquid Chromatography, i.e. countercurrent Chromatography and centrifugal partition Chromatography. To this end, two biphasic systems were selected: the non-aqueous solvent system n-hexane/ethyl acetate/acetonitrile (11.2/2.0/5.3 v/v/v at 25 °C) and the aqueous-organic system n-heptane/ethyl acetate/methanol/water (1/1/1/1 v/v/v/v at 25 °C). The effect of elevated temperature on the separation was systematically analyzed between 25 °C and 40 °C. The results were related to the changes in the Liquid-Liquid equilibria of the solvent systems and physical properties of the phases. The temperature influence on the stationary phase retention, column efficiency and separation resolution was analyzed. An appropriate temperature control of the column was shown to be essential in order to avoid destabilizing the biphasic system and enable a satisfactory separation for temperature sensitive systems. In this context, the influence of different column and mobile phase inlet temperature on the separation performance was investigated by pulse injections. In addition, the stability and settling time of the biphasic systems were evaluated as indicators whether temperature susceptibility needs to be considered during method development in order to prevent a decrease in separation resolution.

  • trapping multiple dual mode centrifugal partition Chromatography for the separation of intermediately eluting components throughput maximization strategy
    Journal of Chromatography A, 2017
    Co-Authors: Raena Morley, Mirjana Minceva
    Abstract:

    Trapping multiple dual mode centrifugal partition Chromatography (trapping MDM CPC) is an alternative to isocratic pulse injections for the separation of intermediately-eluting components from complex mixtures using Liquid-Liquid Chromatography. In this work, a throughput maximization strategy is developed and validated to investigate the full potential of trapping MDM CPC as a preparative technique. In the proposed approach, shake flask and stationary phase retention experiments are used to determine the maximum feed concentration and flow rate, respectively. A model-based parameter selection process combining a mathematical short-cut method and simulations based on the equilibrium cell model is used to obtain the column loading and step durations resulting in maximized process throughput. The proposed throughput maximization strategy is experimentally validated for the separation of a ternary model mixture of parabens. A preliminary comparison of trapping MDM CPC separation performance to that of stacked pulse injections is also made.

Jean-hugues Renault - One of the best experts on this subject based on the ideXlab platform.

  • Polyphenol Purification by Solid Support-Free Liquid-Liquid Chromatography (CCC, CPC) 70
    2020
    Co-Authors: Jane Hubert, Mahmoud Hamzaoui, Jean-hugues Renault
    Abstract:

    In recent years, there has been an increased interest in the use of solid supportfree Liquid–Liquid chromatographic techniques for the purification of polyphenols from natural plant sources. These methods include mainly high-speed countercurrent Chromatography (HSCCC) and centrifugal partition Chromatography (CPC). This chapter presents a summary of all recent HSCCC and CPC studies investigating the fractionation or purification of phenolic compounds from complex plant extracts. This synopsis, covering the last 5 years and comparing over 90 studies, demonstrates that solid support-free Liquid–Liquid

  • Schinus terebinthifolius countercurrent Chromatography (Part III): Method transfer from small countercurrent Chromatography column to preparative centrifugal partition Chromatography ones as a part of method development
    Journal of Chromatography A, 2017
    Co-Authors: Fernanda Das Neves Costa, Jane Hubert, Nicolas Borie, Alexis Kotland, Peter Hewitson, Svetlana Ignatova, Jean-hugues Renault
    Abstract:

    Countercurrent Chromatography (CCC) and centrifugal partition Chromatography (CPC) are support free Liquid-Liquid Chromatography techniques sharing the same basic principles and features. Method transfer has previously been demonstrated for both techniques but never from one to another. This study aimed to show such a feasibility using fractionation of Schinus terebinthifolius berries dichloromethane extract as a case study. Heptane - ethyl acetate - methanol -water (6:1:6:1, v/v/v/v) was used as solvent system with masticadienonic and 3β-masticadienolic acids as target compounds. The optimized separation methodology previously described in Part I and II, was scaled up from an analytical hydrodynamic CCC column (17.4mL) to preparative hydrostatic CPC instruments (250mL and 303mL) as a part of method development. Flow-rate and sample loading were further optimized on CPC. Mobile phase linear velocity is suggested as a transfer invariant parameter if the CPC column contains sufficient number of partition cells.

  • Anion-exchange displacement centrifugal partition Chromatography.
    Analytical Chemistry, 2004
    Co-Authors: Alexandre Maciuk, Jean-hugues Renault, Rodolphe Margraff, Philippe Trébuchet, Monique Zèches-hanrot, Jean-marc Nuzillard
    Abstract:

    Ion-exchange displacement Chromatography has been adapted to centrifugal partition Chromatography. The use of an ionic Liquid, benzalkonium chloride, as a strong anion-exchanger has proven to be efficient for the preparative separation of phenolic acid regioisomers. Multigram quantities of a mixture of three hydroxycinnamic acid isomers were separated using iodide as a displacer. The displacement process was characterized by a trapezoidal profile of analyte concentration in the eluate with narrow transition zones. By taking advantage of the partition rules involved in support-free Liquid-Liquid Chromatography, a numerical separation model is proposed as a tool for preliminary process validation and further optimization.

A. E. Kostanyan - One of the best experts on this subject based on the ideXlab platform.

  • Modeling of two semi-continuous methods in Liquid-Liquid Chromatography: Comparing conventional and closed-loop recycling modes.
    Journal of Chromatography A, 2019
    Co-Authors: A. E. Kostanyan, M. M. Martynova
    Abstract:

    Abstract Two high throughput steady-state methods of counter-current Chromatography separations: conventional (SS CCC) and closed-loop recycling (SS CLR CCC) are proposed, evaluated and compared. The methods are based on the application of semi-continuous sample loading technique: the CCC setup includes two mobile phase tanks – one with the pure mobile phase and the second – with the sample solution in the mobile phase. The mobile phase pump is periodically switching from one tank to another. The sample solution is continuously loaded into the CCC column over a constant time with the constant volumetric rate equal to the flow rate of the pure mobile phase. Analytical expressions are developed to describe the SS CCC and SS CLR CCC separations with semi-continuous sample loading. Examples of separation of binary and multicomponent mixtures are discussed. The SS CLR CCC has been shown to provide a multiple increase in the performance and effectiveness of CCC devices. Several examples of simulation of SS CLR CCC separation with semi-continuous sample loading are presented in “Mathcad” program. For the experimental verification of the theory, the separation of the binary mixture caffeine/ coumarin was studied. The biphasic solvent system hexane/isopropanol/water (1:1:1), was used. The comparison of experimental and simulated separations demonstrated a reasonable agreement between theory and experiment.

  • Theoretical study of separation and concentration of solutes by closed-loop recycling Liquid-Liquid Chromatography with multiple sample injection.
    Journal of Chromatography A, 2017
    Co-Authors: A. E. Kostanyan
    Abstract:

    The method of closed-loop recycling counter-current Chromatography (CLR CCC) with multiple sample injection is proposed for the separation and concentration of a target component of a mixture. Analytical expressions are developed to describe the CLR CCC separations with multiple sample injection. Several possible implementations of multiple feed injection are analyzed: the feed is injected in each cycle, after every two cycles and in an arbitrary cycle. The application of different modes of multiple feed injection to the separation and concentration of the target component from binary mixtures by CLR CCC has been studied. The results of this study indicate that it is possible to achieve simultaneously both the separation and concentration of the target component.

  • Modeling of preparative closed-loop recycling Liquid-Liquid Chromatography with specified duration of sample loading.
    Journal of Chromatography A, 2016
    Co-Authors: A. E. Kostanyan
    Abstract:

    Abstract The closed-loop recycling counter-current Chromatography (CLR CCC) is performed in several consecutive separation stages. First, the loop is opened, and within a specified time the solution of solutes in the mobile phase is continuously fed to the column. After the solutes loading is finished, the loop is closed, and the first separation stage starts. After a certain number of cycles the first fraction of solutes is eluted, the loop is closed, and the second separation stage starts, and so on. In this study, simple equations are presented allowing the simulation of such separation processes. These equations can help to select a suitable compromise between the productivity and the resolution in the preparative and production CLR CCC separations. It is shown that the sample loading time about 20%–30% of the mean residence time is quite acceptable from the practical point of view: proper selection of the loading time and the recycling line length can allow increasing the productivity by an order of magnitude ensuring, a desirable separation.

  • Theoretical study of closed-loop recycling Liquid-Liquid Chromatography and experimental verification of the theory.
    Journal of Chromatography A, 2016
    Co-Authors: A. E. Kostanyan, Andrey A. Erastov
    Abstract:

    Abstract The non-ideal recycling equilibrium-cell model including the effects of extra-column dispersion is used to simulate and analyze closed-loop recycling counter-current Chromatography (CLR CCC). Previously, the operating scheme with the detector located before the column was considered. In this study, analysis of the process is carried out for a more realistic and practical scheme with the detector located immediately after the column. Peak equation for individual cycles and equations describing the transport of single peaks and complex chromatograms inside the recycling closed-loop, as well as equations for the resolution between single solute peaks of the neighboring cycles, for the resolution of peaks in the recycling chromatogram and for the resolution between the chromatograms of the neighboring cycles are presented. It is shown that, unlike conventional Chromatography, increasing of the extra-column volume (the recycling line length) may allow a better separation of the components in CLR Chromatography. For the experimental verification of the theory, aspirin, caffeine, coumarin and the solvent system hexane/ethyl acetate/ethanol/water (1:1:1:1) were used. Comparison of experimental and simulated processes of recycling and distribution of the solutes in the closed-loop demonstrated a good agreement between theory and experiment.

  • Simple equations to simulate closed-loop recycling Liquid-Liquid Chromatography: Ideal and non-ideal recycling models.
    Journal of Chromatography A, 2015
    Co-Authors: A. E. Kostanyan
    Abstract:

    Abstract The ideal (the column outlet is directly connected to the column inlet) and non-ideal (includes the effects of extra-column dispersion) recycling equilibrium-cell models are used to simulate closed-loop recycling counter-current Chromatography (CLR CCC). Simple chromatogram equations for the individual cycles and equations describing the transport and broadening of single peaks and complex chromatograms inside the recycling closed-loop column for ideal and non-ideal recycling models are presented. The extra-column dispersion is included in the theoretical analysis, by replacing the recycling system (connecting lines, pump and valving) by a cascade of Nec perfectly mixed cells. To evaluate extra-column contribution to band broadening, two limiting regimes of recycling are analyzed: plug-flow, Nec → ∞, and maximum extra-column dispersion, Nec = 1. Comparative analysis of ideal and non-ideal models has shown that when the volume of the recycling system is less than one percent of the column volume, the influence of the extra-column processes on the CLR CCC separation may be neglected.

Raena Morley - One of the best experts on this subject based on the ideXlab platform.

  • Operating mode and parameter selection in Liquid-Liquid Chromatography.
    Journal of Chromatography A, 2019
    Co-Authors: Raena Morley, Mirjana Minceva
    Abstract:

    Abstract The presence of a Liquid stationary phase in Liquid–Liquid Chromatography (LLC) allows for high versatility of operation as well as adaptability to different sample types and separation tasks. LLC, also known as countercurrent Chromatography (CCC) or centrifugal partition Chromatography (CPC), offers the user a variety of operating modes, many of which have no direct equivalent in conventional preparative Liquid–solid Chromatography. These operating modes have the potential to greatly improve LLC separation performance compared to the standard “classical” isocratic batch injection mode, and they often require minimal to no addition of equipment to the standard set-up. However, reports of the use of alternative LLC operating modes make up only a fraction of the literature. This is likely due, at least in part, to the lack of clear guidelines and methods for operating mode and parameter selection, leaving alternative process options to be avoided and underutilized. This review seeks to remedy this by providing a thorough overview of the available LLC operating modes, identifying the key characteristics, advantages and disadvantages, and areas of application of each. Additionally, the equations and short-cut models aiding in operating mode and parameter selection are presented and critiqued, and their notation is unified for clarity. By rendering LLC and its alternative operating modes more accessible to current and prospective users, it is hoped to help expand the application of this technology and support the achievement of its full potential.

  • trapping multiple dual mode centrifugal partition Chromatography for the separation of intermediately eluting components throughput maximization strategy
    Journal of Chromatography A, 2017
    Co-Authors: Raena Morley, Mirjana Minceva
    Abstract:

    Trapping multiple dual mode centrifugal partition Chromatography (trapping MDM CPC) is an alternative to isocratic pulse injections for the separation of intermediately-eluting components from complex mixtures using Liquid-Liquid Chromatography. In this work, a throughput maximization strategy is developed and validated to investigate the full potential of trapping MDM CPC as a preparative technique. In the proposed approach, shake flask and stationary phase retention experiments are used to determine the maximum feed concentration and flow rate, respectively. A model-based parameter selection process combining a mathematical short-cut method and simulations based on the equilibrium cell model is used to obtain the column loading and step durations resulting in maximized process throughput. The proposed throughput maximization strategy is experimentally validated for the separation of a ternary model mixture of parabens. A preliminary comparison of trapping MDM CPC separation performance to that of stacked pulse injections is also made.

  • trapping multiple dual mode centrifugal partition Chromatography for the separation of intermediately eluting components operating parameter selection
    Journal of Chromatography A, 2017
    Co-Authors: Johannes Goll, Raena Morley, Mirjana Minceva
    Abstract:

    Abstract The preparative separation of intermediately-eluting components in Liquid-Liquid Chromatography is commonly performed with isocratic batch injections, a technique which often leads to low yield and/or purity as a result of peak overlap. Two-column trapping multiple dual mode centrifugal partition Chromatography, an alternative discontinuous method for the separation of a mixture into three product fractions (early-, intermediately-, and late-eluting components) at full recovery, is presented in this work. A mathematical shortcut method based on equilibrium theory assumptions is derived for the determination of the key operating parameters (i.e., step durations and number of steps). The feasibility of the technique and the accompanying short-cut method is demonstrated by proof-of-concept experiments for the separation of two paraben model mixtures.

Johannes Goll - One of the best experts on this subject based on the ideXlab platform.

  • trapping multiple dual mode centrifugal partition Chromatography for the separation of intermediately eluting components operating parameter selection
    Journal of Chromatography A, 2017
    Co-Authors: Johannes Goll, Raena Morley, Mirjana Minceva
    Abstract:

    Abstract The preparative separation of intermediately-eluting components in Liquid-Liquid Chromatography is commonly performed with isocratic batch injections, a technique which often leads to low yield and/or purity as a result of peak overlap. Two-column trapping multiple dual mode centrifugal partition Chromatography, an alternative discontinuous method for the separation of a mixture into three product fractions (early-, intermediately-, and late-eluting components) at full recovery, is presented in this work. A mathematical shortcut method based on equilibrium theory assumptions is derived for the determination of the key operating parameters (i.e., step durations and number of steps). The feasibility of the technique and the accompanying short-cut method is demonstrated by proof-of-concept experiments for the separation of two paraben model mixtures.

  • Study of the applicability of non-conventional aqueous two-phase systems in counter-current and centrifugal partition Chromatography.
    Journal of Chromatography A, 2015
    Co-Authors: Franziska Bezold, Johannes Goll, Mirjana Minceva
    Abstract:

    Abstract Aqueous two-phase systems composed of imidazolium-based ionic Liquids and phosphate salts were evaluated for their applicability in Liquid–Liquid Chromatography. The influence of the nature of ionic Liquid anion and cation on the partitioning of bovine serum albumin, lysozyme and myoglobin was investigated. A mixture of K2HPO4 and KH2PO4 in a ratio of 1.82:1 wt/wt was used in all of the tested biphasic systems to adjust the pH to a range of 7–8. The results show that more hydrophobic cations decrease the partition coefficients of the proteins in the biphasic systems and outweigh the effect of the anion on the distribution of the macromolecules. Viscosities and densities of the biphasic systems were in a suitable range for Liquid–Liquid Chromatography. Even though the partition coefficients were too high for a conventional batch operation mode, these aqueous two-phase systems show favorable properties for protein capturing in Liquid–Liquid chromatographic columns. Additionally, the possible application of ionic Liquids as modifiers in polyethylene glycol (PEG)-based aqueous two-phase systems was investigated. It could be demonstrated that ionic Liquids alter the partition coefficients of the proteins.