title: On-line affinity selection of histidine-containing peptides using a polymeric monolithic support for capillary electrophoresis.
abstract: An on-line affinity selection method using a polymeric monolithic support is proposed for the retention of histidine-containing peptides and their subsequent separation by capillary zone electrophoresis (CZE). Monolithic capillary columns were prepared in fused-silica capillaries of 150 mum inner diameter (ID) by ionizing radiation-initiated in situ polymerization and cross-linking of diethylene glycol dimethacrylate and glycidyl methacrylate, and chemically modified with iminodiacetic acid (IDA) and copper ion. Monolithic microextractors were coupled on-line near the inlet of the separation capillary (fused-silica capillary, 75 mum ID x 28 cm from the microextractor to the detector). Model peptide mixtures of histidine-containing and histidine-noncontaining peptides were assessed. Peptides were released from the sorbent by a 5 mM imidazole solution and then separated by CZE with ultraviolet detection. Relative standard deviation values for migration times and corrected peak areas were found to be lower than 5.8 and 10.5%, respectively. IDA-Cu(II) ion modified monolithic microextractors showed a chromatographic behavior and could be reused at least 25 times. The use of monolithic supports proved to be an advantageous alternative to packed particles for the preparation of microextractors.
authors: Department of Analytical Chemistry and Physicochemistry, Faculty of Pharmacy and Biochemistry, University of Buenos Aires, Argentina. nvizioli@ffyb.uba.ar
authors: Nora M
authors: NM
authors: Vizioli
authors: Maria Lucía
authors: ML
authors: Rusell
authors: Maria Laura
authors: ML
authors: Carbajal
authors: Clyde N
authors: CN
authors: Carducci
authors: Mariano
authors: M
authors: Grasselli
mesh_terms: D003300:Copper / Q000737:chemistry; D019075:Electrophoresis, Capillary; D006639:Histidine / Q000737:chemistry*; D007098:Imino Acids / Q000737:chemistry; D008689:Methacrylates / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D010455:Peptides / Q000032:analysis*; D012822:Silicon Dioxide / Q000737:chemistry
chemical_list: D007098:Imino Acids; D008689:Methacrylates; D010455:Peptides; C508263:poly(diethylene glycol dimethacrylate-co-glycidyl methacrylate); D006639:Histidine; D012822:Silicon Dioxide; D003300:Copper; C008109:iminodiacetic acid