| 摘要 |
<p>A mass spectrometry method in which notch-filtered noise is applied to an ion trap to resonate all ions except selected parent ions out of the region of the trapping field (16). Preferably, the trapping field is a quadrupole trapping field defined by a ring electrode (11) and a pair of end electrodes (12, 13) positioned symmetrically along a z-axis, and the filtered noise is applied to the ring electrode (11) (rather than to the end electrodes) to eject unwanted ions in radial directions (toward the ring electrode) rather than toward a detector (24) mounted along the z-axis. Application of the filtered noise to the trap in this manner can significantly increase the operating lifetime of such an ion detector.</p> |
