Method of mass spectrometry

摘要

A method of mass spectrometry is disclosed wherein ions are trapped for a period of time T within an AC or RF ion guide maintained at a pressure P wherein the product PxT is at least 1 mbar-ms. The effect of trapping the ions according to a preferred embodiment is that singly charged ions which may, for example, comprise unwanted background ions are substantially lost from the trap whereas multiply charged analyte ions are maintained within the ion trap and can then be released for subsequent mass analysis.