Estimation of Nonlinear Adsorption Isotherms in Gradient Elution RP-LC of Peptides in the Presence of an Adsorbing Additive
نویسندگان
چکیده
ABSTRACT In electrostatic repulsive interaction chromatography, using a charged surface hybrid sorbent carrying positive charges can improve the peak shape of peptides in reversed-phase liquid chromatography (RP-LC), especially in overloaded conditions, compared with standard C18 sorbents. However, the positive surface charges can interact with anionic additives commonly used in peptide separations, e.g., trifluoroacetic acid (TFA), complicating adsorption isotherm estimation. We investigated how the competition for available adsorption sites between TFA and two peptides influenced the adsorption isotherm in gradient elution. A model accounting for the competition with TFA was compared with a model neglecting TFA adsorption. We found that the two models predicted elution profiles with the same accuracy. We also found that the adsorption isotherms were extremely similar in shape, leading to the conclusion that neglecting the competition with TFA is a valid approximation enabling faster and more robust adsorption isotherm estimation for the studied type of sorbent. GRAPHICAL ABSTRACT
منابع مشابه
Stability-indicating UFLC method for uncoupling and estimation of impurities in clopidogrel, aspirin and omeprazole in their tablet dosage form using PDA detection
In this paper a fast and novel stability-indicating ultra fast LC method for separation and estimation of impurities in clopidogrel and aspirin in their combined tablet dosage form and omeprazole was developed. The separation of USP related substances of clopidogrel (A, B and C), aspirin (D), omeprazole (A, B and C) and few other unknown impurities was detected by using ultra fast liquid chroma...
متن کاملComparison of Linear and Nonlinear Kinetic Models and Adsorption Isotherms of Zinc from an Aqueous Solution by Biochar
Fruits and citrus wastes are generated in the food industry in large quantities. Their management in Iran, as one of the major hubs of fruits and citrus production, is of great importance. In this study, the biochar samples were prepared from pomegranate, orange and lemon peel waste produced in a juice factory using the pyrolysis process in the range of 400-500 °C; then their efficiency for zin...
متن کاملRemoval of Hg (I) and Hg (II) Ions from Aqueous Solutions, Using TiO2 Nanoparticles
For the first time, the present study removes ions of mercury, in the form of Hg (I) and Hg (II) ions, from aqueous solutions by adsorbing them onto titanium dioxide nanoparticles. The effects of various parameters, such as solution's initial pH, temperature, sorbent dosage, initial mercury concentration, and contact time have been examined on the adsorption process. The experimental results ha...
متن کاملRemoval of Hg (I) and Hg (II) Ions from Aqueous Solutions, Using TiO2 Nanoparticles
For the first time, the present study removes ions of mercury, in the form of Hg (I) and Hg (II) ions, from aqueous solutions by adsorbing them onto titanium dioxide nanoparticles. The effects of various parameters, such as solution's initial pH, temperature, sorbent dosage, initial mercury concentration, and contact time have been examined on the adsorption process. The experimental results ha...
متن کاملStudying the Adsorption Behavior of a Disperse Dye on Polyethylene Terephthalate in Absence and Presence of a Nanostructured Hyperbranched Polymer
Dyeing properties of compounded polyethylene terephthalate fibers with a polyesteramide hyperbranched polymer were investigated in terms of their thermodynamic parameters, including standard affinity -Δμ⁰, enthalpy change ΔH⁰ and entropy change ΔS⁰. Results were then compared with corresponding properties of the virgin PET. The results showed that the isotherms were similar to that of virgin PE...
متن کامل