A method of reducing diffusion losses in a drift spectrometer

A method is considered which reduces diffusion losses during analysis of the ions of heavy molecules passed together with a carrier gas through a separation system at atmospheric pressure. Separation takes place under the action of a transverse variable electric field in a way similar to the case of quadrupole mass spectrometers. Instead of the usual uniform-field planar capacitor, it is proposed to employ a cylindrical capacitor with a nonuniform field. It is shown experimentally that a severalfold increase in the output signal is achieved. (C) 1999 American Institute of Physics. [S1063-7842(99)02201-1].