| 摘要 |
The method of operating a rod-type mass spectrometer in which precursor ions are introduced into the mass spectrometer together with a collision gas. Sufficient RF voltage, and a small but sufficient amount of resolving DC voltage, are applied to the rods to operate the mass spectrometer near the beta =0 boundary for the precursor ions, thus inducing boundary activated dissociation of at least some of the precursor ions to produce fragment ions. The fragment ions together with any residual precursor ions are directed into a subsequent mass spectrometer for detection and analysis. The method allows moderate mass resolution of the precursor ion which can be used to obtain MSMS information from a single quadrupole and MS3 information from a triple quadrupole. When the DC is scanned over only part of the spectrum, fragmentation information can be obtained within a pre-specified region of the spectrum, and the remainder of the spectrum will display spectral features of unfragmented precursor ions. The method can also be used in the collision cell of a triple quadrupole mass spectrometer, allowing shorter collision cells and cost reduction. The method can also be used to provide efficient declustering of heavily clustered precursor ions of the kind commonly produced by electrospray and ion spray ionization techniques.
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