Theoretical study of system peaks and elution profiles for large concentration bands in the case of a binary eluent containing a strongly sorbed additive

Theoretical study of system peaks and elution profiles of high concentration bands of binary mixtures eluted by a binary eluent containing a strongly retained additive

“…In the latter case Figure 7b), we observe a band profile that exhibits clearly three maxima, while there are only two compounds eluted. The profile of the first compound is very similar to profiles previously reported for single compound profiles under similar conditions (11,12).…”

“…The apparent curvature of the isotherm decreases and, for a given sample size, the band becomes more and more symmetrical, in the same time as its retention time decreases. When the adsorption strength of the strong solvent becomes equal to that of one of the two components of the mixture, the band of this compound becomes almost symmetrical and Gaussian, as we have already reported in the case where a pure compound is injected (11). Figure 2 shows the chromatogram obtained in the case where the isotherm coefficients of the strong solvent and the second component of the pair are equal in eq 2.…”

“…The perturbation of the equilibrium of the additive between the two phases of the chromatographic system, described above, is now generally accepted. The validity of this assumption is demonstrated by the agreement observed between the predictions of the nonlinear theory of chromatography and experimental results (11,12).…”

Theoretical study of system peaks and elution profiles of high concentration bands of binary mixtures eluted by a binary eluent containing a strongly retained additive

“…In the latter case Figure 7b), we observe a band profile that exhibits clearly three maxima, while there are only two compounds eluted. The profile of the first compound is very similar to profiles previously reported for single compound profiles under similar conditions (11,12).…”

“…The apparent curvature of the isotherm decreases and, for a given sample size, the band becomes more and more symmetrical, in the same time as its retention time decreases. When the adsorption strength of the strong solvent becomes equal to that of one of the two components of the mixture, the band of this compound becomes almost symmetrical and Gaussian, as we have already reported in the case where a pure compound is injected (11). Figure 2 shows the chromatogram obtained in the case where the isotherm coefficients of the strong solvent and the second component of the pair are equal in eq 2.…”

“…The perturbation of the equilibrium of the additive between the two phases of the chromatographic system, described above, is now generally accepted. The validity of this assumption is demonstrated by the agreement observed between the predictions of the nonlinear theory of chromatography and experimental results (11,12).…”

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

“…This is important to remember because the composition of the injected sample is usually different from that of the mobile phase and, accordingly, the injection produces a complex perturbation of the equilibrium established in the column prior to the injection. 5 Injection profiles were recorded with the detector connected between the injection valve and the column, thus maintaining the same pressure drop (and presumably flow behavior) as that in the actual chromatographic experiment but replacing the column by a zero-volume connector. Recorded profiles corresponding to the different experimental situations encountered in the present study are shown in Figure 5.…”

“…The relevant boundary condition corresponds to the simultaneous injection of a feed sample and a vacancy of the strong additive on a concentration plateau of the strong additive. This is important to remember because the composition of the injected sample is usually different from that of the mobile phase and, accordingly, the injection produces a complex perturbation of the equilibrium established in the column prior to the injection …”

Theoretical study of system peaks and elution profiles of high concentration bands of binary mixtures eluted by a binary eluent containing a strongly retained additive

“…In the latter case Figure 7b), we observe a band profile that exhibits clearly three maxima, while there are only two compounds eluted. The profile of the first compound is very similar to profiles previously reported for single compound profiles under similar conditions (11,12).…”

“…The apparent curvature of the isotherm decreases and, for a given sample size, the band becomes more and more symmetrical, in the same time as its retention time decreases. When the adsorption strength of the strong solvent becomes equal to that of one of the two components of the mixture, the band of this compound becomes almost symmetrical and Gaussian, as we have already reported in the case where a pure compound is injected (11). Figure 2 shows the chromatogram obtained in the case where the isotherm coefficients of the strong solvent and the second component of the pair are equal in eq 2.…”

“…The perturbation of the equilibrium of the additive between the two phases of the chromatographic system, described above, is now generally accepted. The validity of this assumption is demonstrated by the agreement observed between the predictions of the nonlinear theory of chromatography and experimental results (11,12).…”

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

“…This is important to remember because the composition of the injected sample is usually different from that of the mobile phase and, accordingly, the injection produces a complex perturbation of the equilibrium established in the column prior to the injection. 5 Injection profiles were recorded with the detector connected between the injection valve and the column, thus maintaining the same pressure drop (and presumably flow behavior) as that in the actual chromatographic experiment but replacing the column by a zero-volume connector. Recorded profiles corresponding to the different experimental situations encountered in the present study are shown in Figure 5.…”

“…The relevant boundary condition corresponds to the simultaneous injection of a feed sample and a vacancy of the strong additive on a concentration plateau of the strong additive. This is important to remember because the composition of the injected sample is usually different from that of the mobile phase and, accordingly, the injection produces a complex perturbation of the equilibrium established in the column prior to the injection …”

Theoretical study of system peaks and elution profiles of high concentration bands of binary mixtures eluted by a binary eluent containing a strongly retained additive

“…In the latter case Figure 7b), we observe a band profile that exhibits clearly three maxima, while there are only two compounds eluted. The profile of the first compound is very similar to profiles previously reported for single compound profiles under similar conditions (11,12).…”

“…The apparent curvature of the isotherm decreases and, for a given sample size, the band becomes more and more symmetrical, in the same time as its retention time decreases. When the adsorption strength of the strong solvent becomes equal to that of one of the two components of the mixture, the band of this compound becomes almost symmetrical and Gaussian, as we have already reported in the case where a pure compound is injected (11). Figure 2 shows the chromatogram obtained in the case where the isotherm coefficients of the strong solvent and the second component of the pair are equal in eq 2.…”

“…The perturbation of the equilibrium of the additive between the two phases of the chromatographic system, described above, is now generally accepted. The validity of this assumption is demonstrated by the agreement observed between the predictions of the nonlinear theory of chromatography and experimental results (11,12).…”

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

“…This is important to remember because the composition of the injected sample is usually different from that of the mobile phase and, accordingly, the injection produces a complex perturbation of the equilibrium established in the column prior to the injection. 5 Injection profiles were recorded with the detector connected between the injection valve and the column, thus maintaining the same pressure drop (and presumably flow behavior) as that in the actual chromatographic experiment but replacing the column by a zero-volume connector. Recorded profiles corresponding to the different experimental situations encountered in the present study are shown in Figure 5.…”

“…The relevant boundary condition corresponds to the simultaneous injection of a feed sample and a vacancy of the strong additive on a concentration plateau of the strong additive. This is important to remember because the composition of the injected sample is usually different from that of the mobile phase and, accordingly, the injection produces a complex perturbation of the equilibrium established in the column prior to the injection …”