Method of Correlating Precursor and Fragment Ions

摘要

A method of mass spectrometry is disclosed comprising separating precursor ions using an ion mobility separator such that different precursor ions have different drift times through the on mobility separator; mass filtering said separated precursor ions with a mass filter, wherein the mass to charge ratios of the precursor ions transmitted by the mass filter vary as a function of the drift times of the precursor ions through the ion mobility separator; performing a first mode of operation comprising fragmenting the separated and mass filtered precursor ions in a fragmentation device to form fragment ions; urging the fragment ions through the fragmentation device such that fragment ions derived from different precursor ions that have been separated by the ion mobility separator are maintained spatially separated from each other as they are urged through the fragmentation device; and detecting the fragment ions. The method enables precursor ions to be associated with their related fragment ions more accurately.

主权项

1. A method of mass spectrometry comprising:
separating precursor ions using an ion mobility separator such that different precursor ions have different drift times through the ion mobility separator; mass filtering said separated precursor ions with a mass filter, wherein the mass to charge ratios of the precursor ions transmitted by the mass filter vary as a function of the drift times of the precursor ions through the ion mobility separator; performing a first mode of operation comprising fragmenting or reacting the separated and mass filtered precursor ions in a fragmentation or reaction device to form fragment or product ions; urging the fragment or product ions through the fragmentation or reaction device such that fragment or product ions derived from different precursor ions that have been separated by the ion mobility separator are maintained spatially separated from each other as they are urged through the fragmentation or reaction device; and detecting the fragment or product ions; and performing a second mode of operation in which the separated and mass filtered precursor ions bypass the fragmentation or reaction device, or are transmitted to the fragmentation or reaction device but are substantially not fragmented, wherein the precursor ions are maintained separated according to their ion mobilities as they bypass the fragmentation or reaction device or as they are transmitted through the fragmentation or reaction device, and detecting the precursor ions; wherein the method is repeatedly alternated between said first mode in which fragment or product ions are generated in the fragmentation or reaction device and are detected, and said second mode in which precursor ions are substantially not fragmented and are detected; and wherein the fragment or product ions detected in the first mode are correlated to precursor ions detected in said second mode.