New methods and instrumentation for the characterization of biopolymers using electrospray ionization-mass spectrometry

摘要

The technique of electrospray ionization (ESI) has significantly extended the ability to characterize large molecules by mass spectrometry. Proteins to at least 200,000 D can be transferred intact to the gas phase and molecular weights determined with precisions as high as 0.001% if individual charge states can be resolved. The ESI-MS can also serve as a near ideal interface and detector for capillary column separations providing a basis for highly efficient sample utilization. Using capillary electrophoresis (CE)-MS, injection quantities in the 10(sup (minus)18) mole range can be detected for smaller polypeptides using selected ion monitoring, and separation efficiencies as high as 5(center dot)10(sup 5) theoretical plates have been realized. We have recently shown that the use of small 5 (mu)m i.d. capillaries allows CE-MS with scanning detection for proteins for injection of 600 attomoles.