| 摘要 |
A method of mass spectrometry is disclosed comprising providing a first device 2 and a second device 3 disposed downstream of the first device. The method further comprises reducing the total potential drop across the first and second devices by applying a reverse axial electric field, i.e. one that opposes the onward transmission of ions, to the first device and/or the second device. Ions are driven through the first device and/or the second device against the reverse axial electric field by, for example, a gas flow or using a travelling DC voltage wave or waveform 5. Preferably, a potential difference is introduced between the exit of the first device and the entrance of the second device, said potential difference being adjustable by adjusting the reverse axial field. The potential difference may be used to accelerate ions into a fragmentation cell formed by the second device. |
