Collision cell for tandem mass spectrometry

An arrangement for a tandem mass spectrometer;

• comprising:
• a fragmentation cell containing a plurality of N spatially separate fragmentation cell chambers arranged in parallel with one another, each fragmentation cell chamber having a respective ion entrance for selectively receiving incoming ions from upstream of the fragmentation cell;
• the fragmentation cell further comprising at least one ion exit for ejecting the incoming ions and/or their fragments from the fragmentation cell;
• the arrangement also having:
• a controller configured to control the parameters of the N chambers such that in use, ions entering an ith one of the N chambers experience different fragmentation conditions to ions entering a jth one of the cells (i≠j;
• i≦N, j≦N).

A tandem mass spectrometer comprising:

• an ion source for generating ions to be analysed;
• a first mass analyser configured to separate the ions generated by the ion source into a sequence of precursor ions, each separated in accordance with their mass to charge ratio Mi (i=1 . . . R) such that they emerge from the first stage of mass analysis at different times Ti;
• a fragmentation cell containing a plurality of N spatially separate fragmentation cell chambers arranged in parallel with one another each fragmentation cell chamber having a respective ion entrance for selectively receiving incoming ions from upstream of the fragmentation cell;
• the fragmentation cell further comprising at least one ion exit for ejecting the incoming ions and/or their fragments from the fragmentation cell, the arrangement also having a controller configured to control the parameters of the N chambers such that in use ions entering an ith one of the N chambers experience different fragmentation conditions to ions entering a jth one of the cells (i≠j;
• i≦N, j≦N);
• an ion deflector under the control of the controller and positioned between the first mass analyser and the fragmentation cell, the ion deflector configured to deflect ions of an ith mass Mi arriving at a time ti at the ion deflector from the first mass analyser towards the fragmentation cell for capture and fragmentation by an ith fragmentation cell chamber and to deflect ions of a jth mass Mj (j=1 . . . R;
• j≠i) arriving at a time tj at the ion deflector from the first mass analyser at a time tj towards the fragmentation cell for capture and fragmentation by a jth fragmentation cell chamber;
• and
• a second mass analyser located downstream of the fragmentation cell and adapted to analyse ions ejected from the at least one ion exit of the fragmentation cell.