Atmospheric pressure drift tube ion mobility

Atmospheric pressure drift tube ion mobility is a powerful addition to the Orbitrap mass spectrometer, enabling direct separation of isomers. In addition to offering high resolving power in a compact design, it also facilitates optimization of the separation gas, as shown here for eight pairs of metabolites and gangliosides. About half of the separated compounds showed significantly better analytical separation when analyzed in a mixture of CO2 and air rather than air or CO2 alone.