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 C 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.
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http://dx.doi.org/10.1007/s10337-017-3298-y | DOI Listing |
Heliyon
January 2025
Department of Chemistry, Yazd Branch, Islamic Azad University, Yazd, Iran.
In this research, activated carbon from banana peel (BPAC) was prepared by calcination (600 °C) method. Nano composites MO@BPAC (MO=NiO, CuO and ZnO) were prepared and then were characterized by XRD, FTIR, FESM, EDX, BETand TGA methods. Formation of MO@BPAC nanocomposites was confirmed by analysis methods.
View Article and Find Full Text PDFHeliyon
January 2025
Department of Chemistry, School of Physical Sciences, College of Agriculture and Natural Sciences, University of Cape Coast, Cape Coast, Ghana.
Zeolite was successfully synthesized using a mixture of kaolinite clay (which served as the alumina source) and rice husk ash (silica source). The aim of this work was to synthesize highly efficient zelolite to remove methyle blue dye from aqueous solution. The synthesized adsorbent was characterised using Fourier Transform Infrared (FTIR) spectroscopy, powder x-ray diffraction (PXRD) analysis, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and pH at the point of zero charge (pHpzc).
View Article and Find Full Text PDFRSC Adv
January 2025
Gansu Zhongshang Food Quality Test and Detection Co., Ltd Lanzhou 730010 China.
Ferrihydrite (Fh), a widely distributed mineral in the environment, plays a crucial role in the geochemical cycling of elements. This study used experimental and computational approaches to investigate the adsorption behavior of seven heavy metal ions on Fh. The pH edge analysis revealed that the adsorption capacity followed the order: Pb > Cu > Zn > Cd > Ni > Co > Mn, with Pb showed the highest adsorption.
View Article and Find Full Text PDFPhys Chem Chem Phys
January 2025
UK Catalysis Hub, Research Complex at Harwell, Science and Technology Facilities Council, Rutherford Appleton Laboratory, OX11 0FA, UK.
Methanol adsorption isotherms of fresh f-ZSM-5 and steamed s-ZSM-5 (Si/Al ≈ 40) are investigated experimentally at room temperature under equilibrium and by grand canonical Monte Carlo (GCMC) simulations with the aim of understanding the adsorption capacity, geometry and sites as a function of steam treatment (at 573 K for 24 h). Methanol adsorption energies calculated by GCMC are complemented by density functional theory (DFT) employing both periodic and quantum mechanics/molecular mechanics (QM/MM) techniques. Physical and textural properties of f-ZSM-5 and s-ZSM-5 are characterised by diffuse reflectance infrared Fourier transformed spectroscopy (DRIFTS) and N-physisorption, which form a basis to construct models for f-ZSM-5 and s-ZSM-5 to simulate methanol adsorption isotherms by GCMC.
View Article and Find Full Text PDFEnviron Sci Pollut Res Int
January 2025
Department of Chemical Engineering, Zakir Hussain College of Engineering and Technology, Aligarh Muslim University, Aligarh, 202002, Uttar Pradesh, India.
Water pollution because of the presence of heavy metals remains a serious worry. The present work demonstrates the exclusion of cobalt ion (or Co(II)) from water using novel and cost-effective biosorbents. Initially, the biosorbent was chemically modified using orthophosphoric acid and then subjected to calcination to result acid modified date seed biochar (AMDB).
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