A technique for the detection of nitrogen-containing compounds in gas chromatographic eluates by means of hydrogenolysis and colour reactions

Abstract

A simple technique is described whereby compounds containing nitrogen on being eluted from a gas chromatographic column are detected by means of colour reactions. As they emerge from the column, the compounds are cleaved by hydrogenolysis in a small reactor containing a platinum catalyst to produce ammonia, which is subsequently detected either by the indicator phenolphthalein in a glass porous layer open tubular (PLOT) capillary, or by means of the ninhydrin reagent coated on a PLOT capillary containing activated alumina. The limit of detection for a representative number of nitrogen compounds was 0.2–0.4 μg, and in favourable cases 0.1 μg.