| 摘要 |
<p>A method of operation of an ion trap mass spectrometer which isolates a first group of ions having a mass-to-charge ratio range is disclosed. The method includes producing ions from a plurality of atoms or molecules; trapping the ions in the ion trap by applying a trapping voltage to a ring electrode; applying an excitation voltage to a pair of end-cap electrodes; employing as the excitation voltage a broadband excitation waveform having first, second, and third excitation portions, with the first and third excitation portions exciting the ions excluding substantially all of the first group of ions and also excluding substantially all of a second group of ions having a range of mass-to-charge ratios about the at least one mass-to-charge ratio of the first group of ions, and the second excitation portion exciting the second group of ions; applying the first and third excitation portions in order to eject the ions excluding substantially all of the first and second groups of ions; and applying the second excitation portion in order to sequentially eject the ions excluding substantially all of the first group of ions, thereby isolating the first group of ions in the ion trap. Associated apparatus is also disclosed.</p> |
