SENSITIVITY OF ELECTRON-CAPTURE, FLAME IONIZATION AND THERMIONIC DETECTORS TO VARIOUS NITRO-HALOGENATED AROMATIC-COMPOUNDS

The sensitivity of two specific detectors for gas chromatography, the electron capture (ECD) and the thermionic (TSD) for use in the analysi s of various halogen- and nitro-substituted aromatic compounds was eva luated and compared with that of the universal flame ionization detect or (FID). Minimum detectable and minimum quantifiable amounts and ioni zation efficiency were measured, effects of structure and of position of the substitutent groups in the aromatic ring were evaluated and det ection mechanisms were discussed. A parallel connection of the three d etectors at the end of a single narrow bore capillary column enabled a direct comparison of the chromatograms to be made and their use to be proposed for identification purposes and for analysis of environmenta l samples of chloro-, nitro- and chloro-nitro benzenes within a wide c oncentration range.