| 摘要 |
<p>The invention proposes the generation and superposition of two multipole fields of different order, completely independent of each other, in an RF multipole rod system with at least eight pole rods. For example, in one embodiment it is possible to jointly store low-energy electrons in a central RF quadrupole field generated by a two phase supply HFG1, and multiply charged heavy positive ions in an RF octopole field created by application of a single phase RF voltage to the remaining rods, thereby allowing ions to fragment by electron capture dissociation (ECD). In a different embodiment (see Figure 8), multiply charged positive analyte ions and suitable negative reactant ions can react with each other in an octopole field by electron transfer dissociation (ETD), and the fragment ions can subsequently be formed into fine ion beam by transition to a quadrupole field. A mixture of hexapole and dodecapole fields is also possible.</p> |
