Patent ID: 8344316

Claim:
A mass spectrometer comprising: a first ion trap and a second ion trap arranged downstream of said first ion trap; and a control system which is arranged and adapted: (i) to allow ions to enter said first ion trap for a predetermined period of time, wherein said first ion trap is arranged to have a first charge capacity and wherein if said first charge capacity is exceeded during said predetermined period of time then excess ions will emerge from or otherwise be ejected from said first ion trap; and (ii) to transfer at least some or all ions stored within said first ion trap to said second ion trap after said predetermined period of time; wherein said second ion trap has a second charge capacity, and the ratio of said second charge capacity to said first charge capacity is >1; and wherein said first charge capacity and the charge capacity of said second ion trap is arranged or set so that when at least some or all ions are transferred from said first ion trap to said second ion trap, the analytical performance of said second ion trap is not substantially compromised or the charge capacity of said second ion trap is not substantially exceeded.