QUALITATIVE AND QUANTITATIVE RESPONSE CHARACTERISTICS OF A CAPILLARY GAS-CHROMATOGRAPH ION MOBILITY SPECTROMETER TO HALOGENATED COMPOUNDS

The response of a capillary column gas chromatograph/ion mobility spec trometer (GC/IMS) system to chlorinated and brominated alkanes and alk enes in nitrogen, air and nitrogen/CO2 mixtures was studied. Product i ons were formed through dissociative electron capture processes or cha rge transfer reactions, yielding chloride or bromide ions. The quantit ative response was shown to depend on the composition of the carrier g as in which atmospheric pressure ionization processes occurred as well as on the IMS cell temperature. Large variations in the quantitative response of the GC/IMS to different halogenated compounds were observe d. The results were compared to those reported for the doped electron capture detector (ECD). Practical implications of the GC/IMS system as a monitor and detector for halogenated aliphatic compounds are discus sed.