Abstract
The gas chromatographic method presented in this paper is particularly suitable for the direct analysis of vapours of explosives including ethylene glycol dinitrate (EGDN), ethylene glycol mononitrate (EGMN) and nitroglycerine (NG) with the concentration levels down to 10−12–10−14g/ml. This method includes the use of a sensitive 63Ni electron capture detector (ECD) and a specially designed gas chromatographic column system. Short, mixed liquid phases and combined packed-capillary columns are employed in the G.C. system in order to minimize the adverse factors caused by the adsorption and decomposition effects of some explosives. Consequently, the sensitivity and detectivity of the E.C. detector will be greatly enhanced. Preconcentration procedures are required for detection of explosive vapours below the concentration levels of 10−14g/ml.