A Model for the Description, Simulation, and Deconvolution of Skewed Chromatographic Peaks

Torres-Lapası́o, J.R.; Baeza-Baeza, and J. J.; García-Álvarez-Coque, M.C.

doi:10.1021/ac970223g

Cited by 145 publications

(47 citation statements)

References 20 publications

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“…3). The q/M 2/3 values for each quinolone were obtained at the optimum pH values in the different media (Equation 2 and Table 1) and an electropherogram for the separation of the mixture was easily simulated, by showing a pure Gaussian peak for each quinolone [9,16,35]: where q/M 2/3 are the charge-to-mass ratio values that define the x-scale, h 0 and q i /M i 2/3 are the height and charge-to-mass ratio at the peak maximum for each quinolone, respectively, and s is the SD of the Gaussian peak which is half the value of the width at half height (w 1/2 ) of the simulated electrophoretic peak. A value of 90% was arbitrarily selected as h 0 for all the electrophoretic peaks.…”

Section: Determination Of Electrophoretic Mobility (M E ) Acidity Comentioning

confidence: 99%

Modeling the electrophoretic behavior of quinolones in aqueous and hydroorganic media

et al. 2010

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The applicability of the classical semiempirical relationships between the electrophoretic mobility and charge-to-mass ratio (m e versus q/M a ) has been investigated to describe migration behavior of a series of quinolones in aqueous and hydroorganic media. The Stoke's law (a 5 1/3), the classical polymer model (a 5 1/2) and the Offord's surface law (a 5 2/3) were evaluated in the pH range comprised between 2 and 11 in ACN-water mixtures of 0, 10 and 30% m/m ACN. As accurate acidity constant values were available for charge calculations, correlations were excellent. The results obtained using the Offord's surface law were slightly better and the plots of q/M 2/3 against the separation electrolyte pH were used to select the optimum pH values for separation of a quinolone mixture. The electropherograms simulated considering the accurate charge-to-mass ratio of each quinolone at the selected pH values were in good agreement with the experimental results. The ability of these relationships to predict the separation of the studied quinolones at a certain pH value in methanol-water and THF-water mixtures was also demonstrated.

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Section: Determination Of Electrophoretic Mobility (M E ) Acidity Comentioning

confidence: 99%

Modeling the electrophoretic behavior of quinolones in aqueous and hydroorganic media

et al. 2010

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“…The complexity of the chromatographic process does not allow the use of simple equations to describe peak profiles. The best peak-profile predictions are achieved using a Gaussian equation where the standard deviation depends polynomially on the distance to the peak time (polynomial modified Gaussian model) [11]:…”

Section: Peak Shape Modellingmentioning

confidence: 99%

Retention Behaviour in Micellar Liquid Chromatography

Rambla-Alegre

2012

Chromatography Research International

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Retention in micellar liquid chromatography is highly reproducible and can be modelled using empirical or mechanistic models with great accuracy to predict the retention changes when the mobile phase composition varies (surfactant and organic solvent concentrations), thus facilitating the optimisation of separation conditions. In addition, the different equilibria inside the column among the solute, the mobile phase, and the modified stationary phase by monomers of surfactant have been exhaustively studied. In a sequential strategy, the retention of the solutes is not known a priori, and each set of mobile phases is designed by taking into account the retention observed with previous eluents. By contrast, in an interpretative strategy, the experiments are designed before the optimization process and used to fit a model that will allow the prediction of the retention of each solute. This strategy is more efficient and reliable. The sequential strategy will be inadequate when several local and/or secondary maxima exist, as frequently occurs in chromatography, and may not give the best maximum, that is to say, the optimum. More often than not, the complexity of the mixtures of compounds studied and the relevant modification of their chromatographic behaviour when changing the mobile phase composition requires the use of computer-assisted simulations in MLC to follow the modifications in the chromatograms in detail. These simulations can be done with sound reliability thanks to the use of chemometrics tools.

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“…Peak profiles were described using the polynomially modified Gaussian (PMG) model, which has been demon- strated to fit accurately chromatographic peaks of diverse asymmetry [35,36]:…”

Section: Prediction Of Peak Shapementioning

confidence: 99%

Interpretive optimisation of organic solvent content and flow‐rate in the separation of β‐blockers with a Chromolith RP‐18e column

Pous-Torres

Torres-Lapası́o

Ruiz-Ángel

et al. 2009

J of Separation Science

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The chromatographic performance of a Chromolith RP-18e column was comprehensively examined for a group of basic drugs (beta-blockers), eluted with isocratic ACN-water mixtures at increasing flow-rate up to 6 mL/min. As the flow-rate increases at fixed mobile phase composition, peak distribution (selectivity) is maintained, but the relative peak widths increase. This reduces the resolution below satisfactory values for closely eluting compounds. With the monolithic column, flow-rate becomes thus an important factor to be optimised, in addition to the mobile phase composition. Since, theoretically, retention factors (k) are independent of the flow-rate, the classical quadratic model relating log k with the solvent content allows the prediction of the retention at any combination of organic solvent content and flow-rate. The small deviations found for the most retained compounds were corrected by including, in the quadratic model, an additional term correlating linearly log k with the flow-rate. Peak shape and resolution changes were predicted by taking advantage of the approximated linear relationships between peak half-widths and retention times, which offered similar coefficients for peaks eluting at different organic solvent contents and flow-rates. The accuracy of the predictions in critical conditions was experimentally verified to be satisfactory.

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A Model for the Description, Simulation, and Deconvolution of Skewed Chromatographic Peaks

Cited by 145 publications

References 20 publications

Modeling the electrophoretic behavior of quinolones in aqueous and hydroorganic media

Modeling the electrophoretic behavior of quinolones in aqueous and hydroorganic media

Retention Behaviour in Micellar Liquid Chromatography

Interpretive optimisation of organic solvent content and flow‐rate in the separation of β‐blockers with a Chromolith RP‐18e column

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