A pyrolysis instrument operating with an infrared radiation source in an optical focusing system has been developed to obtain volatile products from solid samples for gas chromatographic/mass spectrometric analysis. The device spatially separates heating source and heated material, avoiding severe contaminations. Solid materials like soil samples or polymeric compounds can be pyrolyzed in the reactor tube of the instrument. Gases formed during the pyrolysis are collected in a sorbent-filled preconcentration tube. The analysis is performed after desorbing the collected gases by gas chromatography/mass spectrometry. Analysis results of the pyrolysis products are then correlated to the compounds in the solid samples.