Speaker: Dat Phan and Peter B. Harrsch, Agilent Technologies, Wilmington, DE

Topic: Practical Aspects and Applications of Interfacing Capillary Electrophoresis and Capillary Electrochromatography with Mass Spectrometry

Place: Building 426, Conference Room, NCI-Frederick, Frederick, MD

Time: Monday, February 14, 2000, at 3:30 PM

Abstract: Capillary electrophoresis (CE) is a powerful analytical technique capable of separating a wide range of molecules. The most common form of CE is capillary zone electrophoresis (CZE) which separates molecules based on charge and mass in a buffer-containing, open bore (50-100 micron) fused silica capillary using high voltage applied across the length of the capillary. Capillary electrochromatography (CEC) utilizes capillaries packed with reversed-phase chromatographic resin. The analyte molecules are driven through the capillary by the liquid flow due to the electro-osmotic flow (EOF) resulting from the voltage applied. To obtain mass spectral data, the outlet end of the capillary is taken out of the CE system and interfaced to the electrospray ionization (ESI) source of the mass spectrometer through a specially-designed nebulizer needle assembly. The nebulizer assembly permits a liquid-liquid junction with sheath liquid allowing electrical conductivity with the internal liquid in the capillary. Typical non-volatile buffers used in CE must be replaced with volatile buffer components in order to minimize ion suppression of the analyte ions and permit detection of the ions by the mass spectrometer. Peptides, proteins, drugs of abuse, pharmaceutical agents, and nutriceuticals have been analyzed by this integrated technique. Practical aspects of interfacing CE and CEC with the mass spectrometer along with criteria for adapting existing methods and developing new methods will be explored.