SPACE CHANGE CONTROL METHOD FOR IMPROVED ION ISOLATION IN ION TRAP MASS SPECTROMETER BY DYNAMICALLY ADAPTIVE SAMPLING

摘要

A method of using a quadrupole ion trap (10) mass spectrometer for high resolution mass spectroscopy is disclosed. In the preferred embodiment, the space charge in the ion trap is controlled to high accuracy. This is done by using a prescan (520) of the trap before each analytical scan (540), where the ionization parameters used in the prescan (520) are not fixed, but rather are based on the previous analytical scan (540). The method is especially useful in connection with performance of high resolution MS/MS experiments of the type described in prior U.S. Patent No. 5,198,665.