| Research Abstract |
In order to establish high-efficiency MS/MS/MS using a magnetic sector mass spectrometer, a collision cell, which can be potentiated at several kilovolts by high-voltage power supply, has been developed. The cell, which is 1 cm in depth, is embedded into the ion-source block which has been newly designed so as to fit with a commercial magnetic sector mass spectrometer. On the basis of ion transmittance of a singly-charged protonated ion accelerated at a 10-kV potential, the voltages applied to the collision cell and to the acceleration plates (a pair of right and left flat plates), which is situated just behind the cell, have been optimized to be 3.0 kV and 1.5 kV, respectively. This setting allowed almost 80% ion transmittance, based on the intensity of a precursor ion, and could provide the product ions specific for high-energy collision-induced dissociation. It is worth mentioning that the efficiency of ion acquisition and the mass resolution, especially, below the mass. of ca. 20% of a precursor mass, have been much improved. The present device could realize MS/MS/MS from a primary product ion, which has been hardly observed in MS1, in low-mass region, using a magnetic four-sector instrument. It will be efficiently applied for structural analysis of biomolecules.
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