Solid-Phase Microextraction procedures for capillary electrophoresis

VIZIOLI NM; CARDUCCI CN; PEÑA C; RUSELL ML; GUZMAN NA

Punta del Este, Uruguay

Simposio; 6th Latin American Symposium on Biomedical, Biopharmaceutical and Industrial Applications of Capillary Electrophoresis and Microchip Technology, LACE 2000; 2000

Last decade, pharmaceutical companies are realigning their strategies in terms of looking for new drug targets and diagnostics utilizing peptides.  Important advances has been obtained in the area of peptide synthesis and control of purity of the peptide of interest.  Recent advances in analytical instrumentation, including advances in capillary electrophoresis, have had a great impact on the ability to separate and detect low quantities of impurities and degradation products generated during the synthesis of peptide drugs. In this presentation, an on-line solid-phase extraction capillary electrophoresis method is described for the control of the purification process of three active biological peptides, which were chemically synthesized.  One is a peptide fragment of a snake toxin called fasciculin.  The other are angiotensin I, and an inhibitor peptide of angiotensin activity.  The laboratory-made devices of the analyte concentrator cartridge were packed with silica-based C18 reverse phase chromatographic material and placed at a distance of 10 cm near the inlet of the capillary.  All solutes were introduce by the hydrostatic mode (syphoning, 10 cm height), followed by washing and equilibration of the column with separation buffer.  A desorption procedure was performed electrokinetically to remove the adsorbed sample employing a solution consisting of acetonitrile: buffer (75: 25, v/v).  The separation of the eluted components was monitored at 214 nm. The optimized experimental conditions allowed the concentration and separation of the main component and its impurities present in the samples analyzed.  Results showed a power concentration of 50 to 200-fold in peak areas when compared to capillary zone electrophoresis without an on-line preconcentration step.  The method precision within and between days were determined. The on-line solid-phase extraction capillary electrophoresis method presented is proposed as a powerful tool for purity testing of various chemically synthesized peptides