On-line affinity selection and preconcetration in capillary electrophoresis using a polymeric monolithic support chemically modified with protoporphyrin IX for peptide analysis

YONE A; RUSELL ML; BRUNO D; PEREZ SE; VIZIOLI NM*

Querétaro, México

Conferencia; 12th Symposium on Biomedical, Biopharmaceutical and Industrial Applications of Capillary Electrophoresis and Microchip Technology; 2006

The identification and quantification of multiple proteins require sensitive and high-throughput analytical technologies. Considerable efforts have been devoted to the development of integrated devices incorporating different components to execute analytical operations. Particularly, the use of selective adsorbents bonded to solid supports in capillary electrophoresis methods has recently received much attention, especially for concentration enrichment, isolation or extraction of analytes and also to achieved microreactions. The on-line affinity selection method proposed in this work makes use of a polymeric monolithic microcolumn chemically modified with iron-protoporphyrin IX (FeProP). Monolithic capillary columns were synthesized by radiation-initiated in situ polymerization of diethylen glycol dimethacrylate and glycidyl methacrylate. FeProP was chemically bonded to the epoxy groups of glycidyl methacrylate residues in the monolithic support structure. The amount of immobilized Fe-ProP was indirectly determined by capillary zone electrophoresis after iron release from the monolith. A piece of monolithic microcolumn, typically 8-mm-long, was coupled on-line near the inlet of the separation capillary. Model peptide mixtures of histidine-containing peptides were assessed. The FeProP microextractors exhibit high affinity toward histidine residues and withstand extensive washings with EDTA. Monolithic supports are considered to play an important role for fast and efficient separation of protein and peptides due to their ease and simplicity of preparation and the availability of a wide range of chemistries.