DATA DEPENDENT MS/MS ANALYSIS

摘要

A method of mass spectrometry is disclosed comprising comparing mass spectral data so as to identify a precursor ion in the mass spectral data that has a predetermined mass difference to a product ion in the mass spectral data; and determining whether said precursor ion is a precursor ion of interest by comparing the ion signal profile for the precursor ion with the ion signal profile for the product ion. If the profiles match then the precursor ion is determined to be an ion of interest. When a precursor ion is determined to be an ion of interest, the precursor ion is isolated from other precursor ions, fragmented or reacted so as to produce product ions, and the product ions are analysed so as to obtain product ion data that can be used to identify the precursor ion.