Catalytic activity in an indium-sensitized flame photometric chlorine detector for gas chromatography

Abstract

A sensltlve detector for halogenated organlc compounds for use in gas chromatography Is descrlbed. The detector Is based on an Indlum-sensltlred dual flame photometric detector. The column effluent Is decomposed In the lower flame, converted to the Indium hallde in the reglon between the flames, and excited In the upper flame to emit at a wavelength that Is characterlstlc of the lndlum hallde. The effect of varlous flame tip materlals on sensltlvlty, for chlorine detectlon, are dlscussed and evidence is shown to support a catalytlcally enhanced mechanlsm for the formation of InCI. Detection limlts In the low pg of Cl/s range have been obtalned by using nickel, tantalum, and actlvated stainless steel flame tlps. The sensltlvlty was found to decrease slowly over long periods of time for the catalytlc materials studled. ' The determination of halogenated organic compounds is of particular interest in connection with environmental pollution. Many analyses that are done in this area by gas chromatography currently use packed columns and electrolytic conductivity detectors for the selective detection of halogens. The use of capillary columns for the analysis of complex environmental samples has become increasingly popular. Electrolytic conductivity detectors are not well suited for use with high-resolution capillary columns. Flame photometric detectors have the advantage of extremely fast response times and are ideal for use with high-resolution and high-speed capillary systems. The indium-sensitized flame photometric detector for