A high-pressure hollow cathode ionizer is combined with an
ion-mobility-spectrometer (IMS) for the detection of trace amounts of
organic compounds in gas. The ionizer uses H.sub.3 0.sup.+, ions which do
not react with air to ionize the organic compounds and the organic
compounds are soft ionized. The ionized organic compounds are detected in
the IMS at levels of parts per billion and identified using calibrated
reference tables. Applications include but are not limited to the fields
of: (1) medicine as a breath analyzer for detection of lung cancer,
diabetes, liver cirrhosis, (2) law enforcement in drug interdiction and
explosives detection, (3) food monitoring and control, (4) environmental
monitoring and (5) space applications.
