Analysis and parametric sensitivity of the behavior of overshoots in the concentration of a charged adsorbate in the adsorbed phase of charged adsorbent particles: practical implications for separations of charged solutes

Zhang, Xiaomin; Grimes, Brian A.; Wang, Jee-Ching; Lacki, K.; Liapis, Athanasios I.

doi:10.1016/j.jcis.2003.10.015

Cited by 30 publications

(57 citation statements)

References 21 publications

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“…The strength of such interactions and the adsorption capacity of the IEX media are assumed to vary inversely with conductivity (Janson and Ryden, 1998). Several models describe the complex adsorption mechanisms in IEX (Brooks and Cramer, 1992;Chang and Lenhoff, 1998;Gallant, 2004;Hunter and Carta, 2000;Lewus and Carta, 2001;Liapis et al, 2001;Nash and Chase, 1998;Zhang et al, 2004a). Confocal microscopy has recently been used to further elucidate the complex nature of IEX adsorption and transport mechanisms (Dziennik et al, 2003;Hubbuch et al, 2002Hubbuch et al, , 2003Kasche et al, 2003;Laca et al, 1999;Linden et al, 1999Linden et al, , 2002Ljunglöf and Hjorth, 1996;Ljunglöf and Thömmes, 1998).…”

Section: Introductionmentioning

confidence: 99%

An exclusion mechanism in ion exchange chromatography

Harinarayan

Mueller

Ljunglöf³

et al. 2006

Biotech & Bioengineering

136

107

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Protein dynamic binding capacities on ion exchange resins are typically expected to decrease with increasing conductivity and decreasing protein charge. There are, however, conditions where capacity increases with increasing conductivity and decreasing protein charge. Capacity measurements on two different commercial ion exchange resins with three different monoclonal antibodies at various pH and conductivities exhibited two domains. In the first domain, the capacity unexpectedly increased with increasing conductivity and decreasing protein charge. The second domain exhibited traditional behavior. A mechanism to explain the first domain is postulated; proteins initially bind to the outer pore regions and electrostatically hinder subsequent protein transport. Such a mechanism is supported by protein capacity and confocal microscopy studies whose results suggest how knowledge of the two types of IEX behavior can be leveraged in optimizing resins and processes. ß

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Section: Introductionmentioning

confidence: 99%

An exclusion mechanism in ion exchange chromatography

Harinarayan

Mueller

Ljunglöf³

et al. 2006

Biotech & Bioengineering

136

107

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“…However, CLSM measurements of intraparticle protein concentrations in certain systems (Hubbuch et al, 2003;Dziennik et al, 2003) have revealed a maximum in protein concentration in the interior of the particle. This ''concentration overshoot'' has been explained by including an additional contribution to the transport equations from a double-layer-induced electrophoretic transport mechanism (Liapis et al, 2001;Zhang et al, 2004). Others have proposed that the overshoot is caused by the displacement of labeled protein by native protein (Carta et al, 2005).…”

Section: Introductionmentioning

confidence: 99%

Competitive adsorption of labeled and native protein in confocal laser scanning microscopy

Teske

Lieres

Schröder

et al. 2006

Biotech & Bioengineering

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Confocal laser scanning microscopy has been previously applied to the study of protein uptake in porous chromatography resins. This method requires labeling the protein with a fluorescent probe. The labeled protein is then diluted with a large quantity of native protein so that the fluorescence intensity is a linear function of the labeled protein concentration. Ideally, the attachment of a fluorescent probe should not affect the affinity of the protein for the stationary phase; however, recent experimental work has shown that this assumption is difficult to satisfy. In the present study, we present a mathematical model of protein diffusion and adsorption in a single adsorbent particle. The differences in adsorption behavior of labeled and native protein are accounted for by treating the system as a two-component system (labeled and native protein) described by the steric mass action isotherm (SMA). SMA parameters are regressed from experimental linear gradient elution data for lysozyme and lysozyme-dye conjugates (for the fluorescent dyes Cy3, Cy5, Bodipy FL, and Atto635). When the regressed parameters are employed in the model, an overshoot in the labeled lysozyme concentration is predicted for Cy5- and Bodipy-labeled lysozyme, but not for Atto635-labeled lysozyme. The model predictions agree qualitatively well with recent work showing the dependence of the concentration overshoot on the identity of the attached dye and provide further evidence that the overshoot is likely caused by the change of binding characteristics due to the fluorescent label.

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“…(1), (2) and (8) could provide a proof of concept, that is, under certain values of (a) the initial surface charge density, d 0 , of the particles where the value of d 0 depends on the value of the pH of the solution as has been shown experimentally [48 -51], and (b) the ionic strength, I v , which affects the value of the characteristic thickness of the electric double layer, k, whether a dynamic concentration overshoot could be obtained for the concentration of the single adsorbate in the adsorbed phase. Indeed a concentration overshoot was shown that could be obtained [18,19] for a single adsorbate being adsorbed onto a charged surface under certain values of pH (the value of pH determines the value of the initial surface charge density, d 0 , as discussed above) and ionic strength, I v , as experimental results obtained by CSLM and UVCM had indicated [6 -9, 11, 32 -36, 52] that was possible to occur in IEC systems involving a single adsorbate. Furthermore, it was found [18,19] that this mathematical model, which could predict that a concentration overshoot in the concentration of the single adsorbate in the adsorbed phase could occur under certain values of pH and ionic strength, could also predict that for the same value of pH (that is, the same value of d 0 ) the magnitude of the concentration overshoot decreases as the value of the ionic strength, I v , increases, and the concentration overshoot phenomenon disappears completely above a certain value of the ionic strength, I v , as has also been observed experimentally [6 -9, 11, 32 -36, 52].…”

Section: Macroscopic Continuum Modelsmentioning

confidence: 99%

“…Indeed a concentration overshoot was shown that could be obtained [18,19] for a single adsorbate being adsorbed onto a charged surface under certain values of pH (the value of pH determines the value of the initial surface charge density, d 0 , as discussed above) and ionic strength, I v , as experimental results obtained by CSLM and UVCM had indicated [6 -9, 11, 32 -36, 52] that was possible to occur in IEC systems involving a single adsorbate. Furthermore, it was found [18,19] that this mathematical model, which could predict that a concentration overshoot in the concentration of the single adsorbate in the adsorbed phase could occur under certain values of pH and ionic strength, could also predict that for the same value of pH (that is, the same value of d 0 ) the magnitude of the concentration overshoot decreases as the value of the ionic strength, I v , increases, and the concentration overshoot phenomenon disappears completely above a certain value of the ionic strength, I v , as has also been observed experimentally [6 -9, 11, 32 -36, 52]. This occurs because the physics of the model accounts properly for the fact that as the value of the ionic strength, I v , increases and the value of k decreases, the magnitude of the initial value of the electrostatic potential, U 0 , also decreases (U 0 represents the value of the zeta potential of the charged surface at t = 0) and, thus, the effect of the electrical phenomena on the transport and adsorption of the charged species decreases significantly.…”

Section: Macroscopic Continuum Modelsmentioning

confidence: 99%

“…Grimes and Liapis [18] studied in detail an IEC system where (i) there was no contribution to the total molar flux of each charged species by convective flow, (ii) there were three charged components with the cations and anions representing components 1 and 2, while the charged adsorbate was representing component 3, (iii) transport of the three species was occurring by diffusion and electrophoretic migration through the stationary hydrodynamic boundary layer surrounding the spherical adsorbent particles employed in the finite bath IEC system of their study, and (iv) adsorption occurred at the charged surface of the spherical adsorbent particles and the adsorption isotherm of the charged adsorbate (component 3) was considered to be described by a Langmuir single component adsorption isotherm. This type of system allowed Grimes and Liapis [18] and Zhang et al [19] to study in detail the implications of the constitutive Eqs. (1), (2) and (8), the effect of the values of the pH and ionic strength, I v , of the liquid solution on the behavior of the constitutive Eqs.…”

Section: Macroscopic Continuum Modelsmentioning

confidence: 99%

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The coupling of the electrostatic potential with the transport and adsorption mechanisms in ion‐exchange chromatography systems: Theory and experiments

Liapis¹,

Grimes

2005

J of Separation Science

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The coupling of the electrostatic potential with the transport and adsorption mechanisms in ionexchange chromatography systems: Theory and experimentsThe coupling of the constitutive expression for the electrostatic potential as specified through Poisson's equation together with the constitutive equations for the mechanisms of convection, diffusion, electrophoretic migration, and adsorption provides the necessary set of constitutive expressions to be employed in the material balance equations of ion-exchange chromatography systems to construct macroscopic continuum models that could be used to design and simulate the dynamic behavior of systems involving a single charged adsorbate or multiple charged adsorbates. A physically relevant and consistent macroscopic continuum model that can predict, as has been observed experimentally by UV confocal microscopy (UVCM), the presence or absence of the concentration overshoot phenomenon, based on the pH and ionic strength of the liquid solution, is discussed and expanded to describe the behavior of IEC systems involving competitive adsorption of two or more charged adsorbates. Furthermore, UVCM and confocal scanning laser microscopy (CSLM) experiments and the macroscopic continuum models that could be used to analyze their data are indicated. Results are also presented that have been obtained from molecular dynamics (MD) modeling and simulation studies (microscopic modeling and analysis) employing realistic atomistic models derived from fundamental physics, and indicate the physical mechanisms that are relevant and actively involved in the transport and adsorption of charged adsorbates in IEC systems, as well as their relative importance. The results obtained from the MD simulations show that when a charged macromolecule is adsorbed it is restrained by a strong dominant Coulombic interaction and is trapped by a hydration layer adjacent to the surface and these lead to zero lateral displacement of the adsorbed macromolecule. This finding indicates that surface diffusion could be a physically implausible mechanism in IEC systems involving charged adsorbate macromolecules. Also, the results obtained from the MD simulation studies show that the transport coefficients that characterize the mass transfer of a charged adsorbate in the liquid solution by diffusion and electrophoretic migration have magnitudes along the lateral direction that are different from those along the direction that is normal to the charged surface.

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Analysis and parametric sensitivity of the behavior of overshoots in the concentration of a charged adsorbate in the adsorbed phase of charged adsorbent particles: practical implications for separations of charged solutes

Cited by 30 publications

References 21 publications

An exclusion mechanism in ion exchange chromatography

An exclusion mechanism in ion exchange chromatography

Competitive adsorption of labeled and native protein in confocal laser scanning microscopy

The coupling of the electrostatic potential with the transport and adsorption mechanisms in ion‐exchange chromatography systems: Theory and experiments

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