An apparatus is described that allows the collection, within a matrix of condensed inert gas, of the effluent compounds from a high-resolution gas chromatograph. Each collected compound is contained within an area typically 0. 3 mm in diameter yielding a concomitant high level of infrared spectral absorbance per nanogram of sample. Tests demonstrate the level of infrared sensitivity, the achievement of matrix isolation of the sample molecules, and the maintenance of compound separation achieved by the gas chromatograph. Use of the apparatus is demonstrated for PAH, PCB, dioxin, and aliphatic hydrocarbon compounds.