A specific detector for nitrogen and halogen compounds in TLC on coated quartz rods

A new detector has been developed for use with the Iatroscan TH‐10 TLC/FID instrument‐a “solid‐phase” chromatographic system (SPC). This new detection system contains a unique stage of detection that is called a flame thermionic ionization detector or FTID. The FTID evolved from a similar device that recently has been used in gas chromatography. The basic concept of an FTID is that organic sample compounds are first decomposed by combustion in an H2‐air flame. The FTID does not sense any of the ionization produced directly in the flame but, instead, re‐ionizes the combustion products by means of a unique thermionic transducer placed in the downstream effluent of the flame. The thermionic transducer ionizes specifically only those combustion products which are acidic or electronegative in chemical activity. In particular, organic samples containing nitrogen (N) or halogen atoms combust to products which are especially well detected with high sensitivity. Hence, the FTID adds to the Iatroscan a state‐of‐the‐art detection stage which produces large signals for nitrogen and halogen compounds and negligible signals for hydrocarbon compounds.