Apparatus for spectroscopic analysis of chemical compounds in samples released from a gas chromatograph is configured for placing the samples in matrix isolation for exposure to a beam of light generated from a spectrometer. The apparatus includes a vacuum chamber, housing a generally cylindrical, axially rotating sample disk having an axle and a mirrored surface, which is provided for receiving the samples from the gas chromatograph. A support block supports the rotating disk within the vacuum chamber. Also included in the apparatus is a cooling device which is in contact with the support block for cryogenically cooling the mirrored surface. Further, the disk is configured such that it rotates relative to the stationary cooling device. Also featured is a sample deposition apparatus which displaces a sample deposition nozzle to avoid contamination of the mirrored surface, and positions the deposition nozzle relative to the sample disk to obtain real time sample analysis.