Derivation of adsorption capacity and adsorption isotherm by a single adsorbate concentration in liquid-solid system

A novel approach was presented as a strategy for deriving adsorption capacity and isotherm by a single adsorbate concentration in the liquid-solid system with experimental proof utilizing frontal chromatography (FC). A breakthrough curve equation presented in this work shows the dependence of adsorbate concentration in feed solution on time in FC and can be used to derive three characteristic binding parameters n (the number of the adsorbates bound to adsorbents), K (the adsorption equilibrium constant of adsorbates) and n(a) (the total number of the adsorption sites). Moreover, the adsorption capacity and isotherm could be derived by a single breakthrough curve, even part of it. The equation was verified with the breakthrough curves of some arene and proteins on reversed-phase, ion-exchange, hydrophobic and affinity media, showing good fitness and consistent with the classical static method and elution peak method. Besides, all the adsorption data were referred to the type I adsorption of the Langmuir isotherm. This work presented new insight that utilizing a single breakthrough curve to determine adsorption parameters and isotherms and may provide some perspective for the determination of physico-chemical property and performance study of very rare substances.

Automated summary

A novel approach utilizing frontal chromatography was presented to derive adsorption capacity and isotherm by a single adsorbate concentration in the liquid-solid system. The breakthrough curve equation can be used to determine characteristic binding parameters and the method was verified with good fitness. This method may provide insight for studying physico-chemical properties and performance of rare substances.