On-line affinity selection of histidine-containing peptides using a polymeric monolithic support for capillary electrophoresis

VIZIOLI, N.M.; RUSELL, M.L.; CARBAJAL, M. L.; CARDUCCI, C.N.; MARIANO GRASSELLI

ELECTROPHORESIS

WILEY-V C H VERLAG GMBH

Año: 2005 vol. 26 p. 2942 - 2948

0173-0835

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 m inner diameter (ID) by ionizing radiation-initiated in situ polymerization and crosslinking 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 from the microextractor to the detector). Model peptide mixtures of histidine-containing and histidine-non containing peptides were assessed. Peptides were released from the sorbent by a 5 mM" imidazole solution and then separated by CZE with UV detection. The relative standard deviation (RSD) values for migration times and corrected peaks 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 re-used at least 25 times. The use of monolithic supports proved to be an advantageous alternative to packed particles for the preparation of microextractors.