Polarization dielectric discharge source for IMS instrument

An ionizing apparatus for use in ionizing molecules in a test sample to be analyzed using an ion-mobility spectrometer, the apparatus comprising:

• a first conductor, a second conductor, and a dielectric, the first conductor, second conductor, and dielectric being sized, shaped and mutually positioned such that when the first conductor and second conductor are energized to an ionization voltage, discharge ionization occurs at an interface between the first conductor and the dielectric;
• the dielectric comprising a glass element formed in a tubular shape so as to define an inner wall of a tube, the dielectric being positioned between the first conductor and the second conductor to insulate the first conductor from the second conductor;
• the first conductor comprising a wire formed in coils that are in contact with said inner wall, and being electrically connectable to an AC voltage pulse generator;
• the second conductor comprising a conducting layer positioned so as to define an outer wall of the tube, and being electrically connectable to the AC voltage pulse generator;
• and
• the tube comprising an inlet end for receiving the sample, and an outlet end through which the sample exits after ionization,
• wherein the first conductor is coated with a substance having an affinity for organics to enhance trapping of the sample on the first conductor.