High-Concentration Band Profiles and System Peaks for a Ternary Solute System

Abstract

High-concentration HPLC band profiles of single solutes and the individual band profiles of the components of binary and ternary mixtures are reported for benzyl alcohol, 2-phenylethanol, and 2-methylbenzyl alcohol. These solutes were eluted from a C18 column by a binary mobile phase (MeOH:H2O = 1:1, v/v). High-concentration system peaks were obtained using mixtures of benzyl alcohol and 2-phenylethanol at different relative concentrations as the feed and 2-methylbenzyl alcohol as the strong mobile phase additive. Band profiles and system peak profiles were calculated using the equilibrium-dispersive model of chromatography. The adsorption equilibrium in the multicomponent system was characterized by the competitive Langmuir model. Excellent quantitative agreement was found between the experimental and the calculated profiles. This work confirms that extremely unusual system peak profiles can be obtained even when the adsorption behavior is quite simple. Under certain circumstances, the use of a properly chosen additive could markedly increase the separation between bands and hence the production rate, the recovery yield, and/or the purity of the fractions.

Introducing the Adsorption Energy Distribution Calculation for Two-Component Competitive Adsorption Isotherm Data

“…This also indicates that the simple competitive Langmuir model is insufficient for describing the adsorption process. This aligns well with the findings of Quiones et al 12 In their study, they developed an adsorption isotherm based on nonideal adsorbed solution theory to fit the same experimental data, noting that their model reduced to a Langmuir-type expression only under certain conditions. However, their model development was primarily driven by statistical improvements in their model fit.…”

“…System 2: Frontal analysis (FA) and frontal analysis by elution by characteristic points (FACP) two-component adsorption isotherm data of benzyl alcohol (BA), 2-phenylethanol (PE), and 2-methylbenzyl alcohol (MBA) on a Symmetry C18 column were taken from Quiñones et al 12 The eluent used was 50/50 (v/v) methanol/water. Each adsorption isotherm contained 130 data points for FACP and 50 data points for FA.…”

Introducing the Adsorption Energy Distribution Calculation for Two-Component Competitive Adsorption Isotherm Data

“…This also indicates that the simple competitive Langmuir model is insufficient for describing the adsorption process. This aligns well with the findings of Quiones et al 12 In their study, they developed an adsorption isotherm based on nonideal adsorbed solution theory to fit the same experimental data, noting that their model reduced to a Langmuir-type expression only under certain conditions. However, their model development was primarily driven by statistical improvements in their model fit.…”

“…System 2: Frontal analysis (FA) and frontal analysis by elution by characteristic points (FACP) two-component adsorption isotherm data of benzyl alcohol (BA), 2-phenylethanol (PE), and 2-methylbenzyl alcohol (MBA) on a Symmetry C18 column were taken from Quiñones et al 12 The eluent used was 50/50 (v/v) methanol/water. Each adsorption isotherm contained 130 data points for FACP and 50 data points for FA.…”

Numerical gradient methods for flux identification in a system of conservation laws

“…18. The results on the chromatograms are good; in particular, we still have the correct position of shocks, which was not so good in [5].…”

“…15, the fit with experimental chromatograms in Fig. 16 with solid lines (-), together with the simulations of [5] (dashed lines −−). Several comments are in order here.…”

“…First, it is clear that the fit on the isotherms is worse for simulated parameters. This emphasizes the fact that the kind of data we used to identify are completely different from those of [5]. The concentration range of the chromatograms is not the same as in the isotherm data, and in particular we have no information at all on the single-component adsorption ( in Figs.…”

Introducing the Adsorption Energy Distribution Calculation for Two-Component Competitive Adsorption Isotherm Data

“…This also indicates that the simple competitive Langmuir model is insufficient for describing the adsorption process. This aligns well with the findings of Quiones et al 12 In their study, they developed an adsorption isotherm based on nonideal adsorbed solution theory to fit the same experimental data, noting that their model reduced to a Langmuir-type expression only under certain conditions. However, their model development was primarily driven by statistical improvements in their model fit.…”

“…System 2: Frontal analysis (FA) and frontal analysis by elution by characteristic points (FACP) two-component adsorption isotherm data of benzyl alcohol (BA), 2-phenylethanol (PE), and 2-methylbenzyl alcohol (MBA) on a Symmetry C18 column were taken from Quiñones et al 12 The eluent used was 50/50 (v/v) methanol/water. Each adsorption isotherm contained 130 data points for FACP and 50 data points for FA.…”

Numerical gradient methods for flux identification in a system of conservation laws

“…18. The results on the chromatograms are good; in particular, we still have the correct position of shocks, which was not so good in [5].…”

“…15, the fit with experimental chromatograms in Fig. 16 with solid lines (-), together with the simulations of [5] (dashed lines −−). Several comments are in order here.…”

“…First, it is clear that the fit on the isotherms is worse for simulated parameters. This emphasizes the fact that the kind of data we used to identify are completely different from those of [5]. The concentration range of the chromatograms is not the same as in the isotherm data, and in particular we have no information at all on the single-component adsorption ( in Figs.…”

Introducing the Adsorption Energy Distribution Calculation for Two-Component Competitive Adsorption Isotherm Data

“…This also indicates that the simple competitive Langmuir model is insufficient for describing the adsorption process. This aligns well with the findings of Quiones et al 12 In their study, they developed an adsorption isotherm based on nonideal adsorbed solution theory to fit the same experimental data, noting that their model reduced to a Langmuir-type expression only under certain conditions. However, their model development was primarily driven by statistical improvements in their model fit.…”

“…System 2: Frontal analysis (FA) and frontal analysis by elution by characteristic points (FACP) two-component adsorption isotherm data of benzyl alcohol (BA), 2-phenylethanol (PE), and 2-methylbenzyl alcohol (MBA) on a Symmetry C18 column were taken from Quiñones et al 12 The eluent used was 50/50 (v/v) methanol/water. Each adsorption isotherm contained 130 data points for FACP and 50 data points for FA.…”

Numerical gradient methods for flux identification in a system of conservation laws

“…18. The results on the chromatograms are good; in particular, we still have the correct position of shocks, which was not so good in [5].…”

“…15, the fit with experimental chromatograms in Fig. 16 with solid lines (-), together with the simulations of [5] (dashed lines −−). Several comments are in order here.…”

“…First, it is clear that the fit on the isotherms is worse for simulated parameters. This emphasizes the fact that the kind of data we used to identify are completely different from those of [5]. The concentration range of the chromatograms is not the same as in the isotherm data, and in particular we have no information at all on the single-component adsorption ( in Figs.…”