Development of a short pulsed corona discharge ionization source for ion mobility spectrometry

The development of a pulsed corona discharge ionization source and its use in ion mobility spectrometry (IMS) is presented. In a point-plane electrode geometry, an electrical pulse up to 12 kV, 150 ns rise time and 500 ns pulse width was used to generate a corona discharge in air. A single positive high voltage pulse was able to generate about 1.6x10(10) ions at energy consumption of 22 mu J. Since the temporal distribution of ions is in a pulsed form, the possibility of removal the ion gate has been investigated. By purposely arranging the interface between discharge field and drift field, nearly 10(7) positive ions were drawn into the drift region with absence of the ion gate after every single discharge. The positive spectrum of acetone dimer (working at room temperature) was obtained with a resolving power of 20 by using this configuration. The advantages of this new scheme are the low power consumption compared with the dc method as well as the simplicity of the IMS cell structure. (c) 2005 American Institute of Physics.