Detection of explosives by ion mobility spectroscopy has become common in recent years. We demonstrate explosive
detection with a novel Laser Ion Mobility Spectrometer (LIMS) developed at EADS Innovation Works. A Laser
operating at 266nm was used for the two-photon ionisation of dopant and calibrant substances. Quantitative
measurements of trace residues of explosives have been performed to quantify the sensitivity of the LIMS system.
Findings demonstrate the suitability of this technique as a screening tool for explosive compounds.
Trace detection of toxic industrial compounds has been investigated with the help of a laser ion mobility spectrometer
(LIMS). The LIMS was equipped with a tuneable UV laser source for enabling two-photon ionization of the analyte
gases and an ion drift tube for the measurement of the ion mobility. Different aromatic and aliphatic hydrocarbons as
well as amines were investigated. We find that the first class of molecules can be well ionized due to the delocalization
of their valence electron shells and the second due to the presence of non-bonding electrons in lone-pair orbitals.
Selectivity of detection is attained on the basis of molecule-specific photo-ionization and drift time spectra. Ion currents
were found to scale linearly with the substance concentration over several orders of magnitude down to the detection
limits in the ppt range. As besides toxic industrial compounds, similar electron configurations also occur in illicit drugs,
toxins and pharmaceutical substances, LIMS can be applied in a variety of fields ranging from environmental analysis,
air pollution monitoring, drug detection and chemical process monitoring.