Patent ID: 9373493
Filing Date: 2016-06-21
CPC Classification: H01J

Claim Text:
1. A mass spectrometer comprising: an ion source for ionizing a sample; a first mass analyzer for selecting first desired ions from the ions generated in the ion source according to mass-to-charge ratio; a collision cell for fragmenting some or all of the first desired ions into product ions having electrodes controlling entrance and exit to and from said cell; a second mass analyzer for selecting second desired ions from the first desired ions and the product ions according to mass-to-charge ratio; a detector for detecting the second desired ions; and a control section having a computer programmed for controlling the entrance and exit electrodes of the collision cell, said control section programmed for storing a target value of a ratio of the amount of the second desired ions ejected from the collision cell by an opening operation to the amount of the second desired ions stored in the collision cell immediately prior to the opening operation permitting a tolerable range of interference between transitions performed in succession, said control section programmed to control the entrance and exit electrodes to provide a measurement mode such that the collision cell performs a storing operation for storing the first desired ions and the product ions for a given storage time and then performs the opening operation for ejecting the stored ions for a given opening time consistent with said target value, said control section programmed to provide an adjustment mode by varying the opening time to adjust the given opening time for ejecting stored ions to be consistent with said target value of the ratio of ejected second ions to stored second desired ions.