A new apparatus for gas-phase separation of stable elemental isotopes at at
mospheric pressure is described. A gaseous mixture of chloride isotopes was
generated using electrospray ionization and introduced into the analyzer r
egion of a high-field asymmetric waveform ion mobility spectrometer (FAIMS)
. The ion current exiting the FAIMS was sampled into a quadrupole mass spec
trometer for isotope identification. (C) 2000 Elsevier Science B.V. All rig
hts reserved.