Ramsey Research GroupThe University of North Carolina at Chapel Hill

Department of Chemistry

Tandem MS

Tandem mass spectrometry is a useful method for gaining further information about the identity of an analyte compound, particularly in a complex mixture. In ion traps, tandem mass spectrometry is frequently performed via isolation of a specific mass-to-charge ion followed by excitation and analysis. Due to the high pressures (~1 Torr) of buffer gas (helium, nitrogen, or air) in our methodology, our trapped ions undergo many more collisions with neutral bath gas molecules than in conventional techniques. These collisions lead to suppression of the secular frequencies, which are motions dependent on the mass-to-charge ratio of the specific ion. Interactions with these frequencies by applying an AC voltage to the endcaps at a matching frequency can cause ejection or excitation leading to fragmentation.


tandom MS