Patent ID: 6878933

Claim:
A method for injecting ions into a quadrupole ion trap mass spectrometer (QIT-MS), comprising: cycling a QIT-MS through a plurality of radiofrequency (RF) amplitude levels, each RF amplitude level corresponding to the storing of ions in one of a corresponding plurality of ranges of ion mass-to-charge ratios; incidenting a plurality of laser pulses on a sample during cycling the QIT-MS through a plurality of RF amplitude levels, wherein sample ions are generated each time one of the plurality of laser pulses in incident on the sample; and injecting the sample ions generated each time one of the plurality of laser pulses is incident on the sample into the QIT-MS such that a corresponding plurality of ion pulses is produced; wherein incidenting the plurality of laser pulses on the sample is synchronized with cycling of the QIT-MS through the plurality of RF amplitude levels such that the same number of ion pulses are produced during each of the plurality of RF amplitude levels.