Research Interests:
Research Interests:
Polymethacrylate-based monolithic capillary columns, prepared by γ-radiation-induced polymerization, were used to optimize the experimental conditions (nature of the organic modifiers, the content of trifluoroacetic acid and the column... more
Polymethacrylate-based monolithic capillary columns, prepared by γ-radiation-induced polymerization, were used to optimize the experimental conditions (nature of the organic modifiers, the content of trifluoroacetic acid and the column temperature) in the separation of nine standard proteins with different hydrophobicities and a wide range of molecular weights. Because of the excellent permeability of the monolithic columns, an ion-pair reversed-phase capillary liquid chromatography with high-resolution mass spectrometry method has been developed by coupling the column directly to the mass spectrometer without a flow-split and using a standard electrospray interface. Additionally, the high working flow and concomitant high efficiency of these columns allowed us to employ a longer column (up to 50 cm) and achieve a peak capacity value superior to 1000. This work is motivated by the need to develop new materials for high-resolution chromatographic separation that combine chemical stab...
Research Interests:
The structural and chromatographic characterization of two novel fluorinated mesoporous materials prepared by covalent reaction of 3-(pentafluorophenyl)propyldimethylchlorosilane and perfluorohexylethyltrichlorosilane with 2.5 μm fully... more
The structural and chromatographic characterization of two novel fluorinated mesoporous materials prepared by covalent reaction of 3-(pentafluorophenyl)propyldimethylchlorosilane and perfluorohexylethyltrichlorosilane with 2.5 μm fully porous silica particles is reported. The adsorbents were characterized by solid state (29)Si, (13)C, and (19)F NMR spectroscopy, low-temperature nitrogen adsorption, elemental analysis (C and F), and various chromatographic measurements, including the determination of adsorption isotherms. The structure and abundance of the different organic surface species, as well as the different silanol types, were determined. In particular, the degree of so-called horizontal polymerization, that is, Si-O-Si bridging parallel to the silica surface due to the reaction, under "quasi-dry" conditions, of trifunctional silanizing agents with the silica surface was quantified. Significant agreement was found between the information provided by solid-state NMR,...
Research Interests: Chemistry, NMR Spectroscopy, Magnetic Resonance Spectroscopy, Medicine, Surface Chemistry, and 12 moreAdsorption, Elemental analysis, Surface modification, High Performance Liquid Chromatography, Silanol, High Pressure Liquid Chromatography, CHEMICAL SCIENCES, Liquid Chromatography, Mesoporous Silica, Silicon Dioxide, Halogenation, and Mesoporous Material
Research Interests:
Research Interests: Chemistry, Inorganic Chemistry, Organic Chemistry, Catalysis, Kinetics, and 15 moreMass Spectrometry, Medicine, Stereochemistry, Hydrogenation, Antimalarials, Artemisia Annua, Molecular Conformation, Artemisinin, American Chemical Society, Molecular Structure, Solvents, Hemiacetal, dihydroartemisinin, Human Plasma, and electrochemical detection
Research Interests: Chemistry, Analytical Chemistry, Chromatography, Pharmaceutical Chemistry, Medicine, and 15 moreComputer Simulation, Temperature, High Performance Liquid Chromatography, High Pressure Liquid Chromatography, Particle Size, Antimalarials, Thermal Decomposition, Low Temperature, Flow Rate, Chromatographic separation, Biochemistry and cell biology, Terpenoid, dihydroartemisinin, Pharmacology and pharmaceutical sciences, and HPLC Chromatography
Research Interests:
Research Interests: Engineering, Chemistry, Chromatography, Gamma Rays, Cancer Therapy, and 15 moreHIstone Deacetylase, Fused Silica Etching, Cluster Analysis, High Performance Liquid Chromatography, Enzyme, High Pressure Liquid Chromatography, CHEMICAL SCIENCES, Histones, Histone deacetylase inhibitor, Flow Velocity, Histone Acetylation, Ethylene Glycol, Histone deacetylase inhibitors, Electrospray Ionization, and fused silica
Research Interests: Engineering, Chemistry, Chromatography, Kinetics, Medicine, and 15 moreCase Study, Silica, High Performance Liquid Chromatography, High Pressure Liquid Chromatography, CHEMICAL SCIENCES, High performance, High Resolution, High Speed, Enantioselective Synthesis, Particle Size, enantioselective HPLC, Silicon Dioxide, Drug Stability, Enantiomer, and Chloroform
The development of epoxy organic monoliths with modulated hydrophilicity for the preparation of novel trypsin-based microreactors is reported. Porous polymer monoliths have been prepared using methacrylate chemistry triggered by γ-ray... more
The development of epoxy organic monoliths with modulated hydrophilicity for the preparation of novel trypsin-based microreactors is reported. Porous polymer monoliths have been prepared using methacrylate chemistry triggered by γ-ray irradiation. In situ polymerization has been optimized and extended to medium and high polymer densities using glycidyl methacrylate (GMA) as reactive monomer as well as to the hydrophilic nature of the co-monomers (glyceryl monomethacrylate, GlyMA and acrylamide, AMD). Enzyme immobilization was smoothly achieved by passing a buffered trypsin solution through the columns kept at room temperature. The activities of the immobilized enzyme were characterized by the apparent Michaelis constant (K(m)) and the apparent maximum velocity (V(max)) of the reaction using a non chromogenic, low-molecular mass substrate N-α-benzoyl-l-arginine ethyl ester (BAEE). For the kinetic constants determination a new off-line chromatographic procedure was developed on purpose. The most efficient IMERs were obtained by immobilizing trypsin on monolithic skeleton prepared with hydrophilic monomers (GlyMA and AMD). One of the most promising bioreactor was applied to the digestion of model proteins with different molecular weight and complexity such as human serum albumin (HSA), β-casein and ribonuclease B (RNase B), and the produced peptides were analyzed by liquid chromatography-mass spectrometry. Using a digestion time of only 25 min the proteins were recognized by the database with satisfactory sequence coverage, which was 78.22, 49.76 and 80.68% for HSA, β-casein and RNase B, respectively.