Patent ID: 9583321
Date: 2017-02-28
CPC Classifications: H01J

Claim:
1. A method for operating a mass spectrometer comprising: (a1) introducing a first portion of a sample of ions into a first mass analyzer of the mass spectrometer, the sample including precursor ions comprising a first precursor-ion mass-to-charge (m/z) ratio; (b1) transmitting the precursor ions comprising the first precursor-ion m/z ratio from the first mass analyzer into an elongate trapping volume of a reaction or fragmentation cell of the mass spectrometer through an entrance end thereof such that a first population of product ions generated within the fragmentation or reaction cell from the precursor ions are continuously accumulated within the elongate trapping volume over a first accumulation time period, wherein the reaction or fragmentation cell further comprises an exit end and wherein the fragmentation or reaction cell includes a single set of electrodes, the single set of electrodes consisting essentially of a set of multipole rods disposed parallel to the elongate trapping volume, a first electrostatic lens disposed at the entrance and a second electrostatic lens disposed at the exit end; (c1) initiating release of the accumulated first population of product ions from the reaction or fragmentation cell through the exit end; (d1) continuously transmitting the released first population of product ions from the reaction cell to a second mass analyzer of the mass spectrometer; (e1) transmitting a portion of the released first population of product ions from the second mass analyzer to a detector of the mass spectrometer, said portion comprising a first product-ion m/z ratio; and (f1) detecting a varying quantity of the portion of the released first population of product ions having the first product-ion m/z ratio with the detector for a predetermined data-acquisition time period after the initiation of the release of the accumulated first population of product ions, wherein a duration of the first accumulation time period is chosen such that the initiation of the release of the accumulated first population of product ions from the reaction or fragmentation cell encompasses a time during which a rate of destruction of product ions comprising the first product-ion m/z ratio within the reaction or fragmentation cell is equal to the rate of generation of the product ions comprising the first product-ion m/z ratio within the reaction or fragmentation cell.