| 摘要 |
<p>A mass spectrometry method in which notch-filtered noise is applied to an ion trap to resonate all ions except selected reagent ions out of the region (16) of the trapping field. 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 (12, 13)} to eject unwanted ions in radial directions {toward the ring electrode (11)} 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> |
