| 摘要 |
A method of mass spectrometry comprises providing a collision or reaction cell (e.g. RF quadrupole ion guide or ion trap) and causing parent ions to collide, react, dissociate or fragment so as to form product or daughter ions. A broadband excitation 3 with frequency notches 4 is applied to the collision or reaction cell so as to cause the product ions to be substantially ejected from the collision or reaction cell whilst parent ions remain trapped. The missing notch frequencies may be around the secular frequencies of the parent ions and reagent ions (A, B). Product ions (C, D) may be radially excited before being axially ejected. The invention may improve efficiency and control of gas phase reactions in mass spectrometers by ensuring product or fragment ions are effectively removed as soon as they are formed and preventing product or fragment ions from undergoing further reactions or being charge neutralised. |
