Comparison of light pipe, matrix isolation, and cryotrapping GC-FTIR

An inter-laboratory comparison has been carried out of three types of GC-FTIR interfacing: light-pipe, matrix isolation, and cryotrapping. Representative samples of industrial and environmental origin have been analyzed in parallel. Instruments utilizing sample storage of the GC-eluent are found to yield considerably better sensitivity than the light-pipe system. The chromatographic resolution was hardly degraded. Spectra obtained often show features characteristic to the interface used. Synchronous use of an FID or MS detector was found to allow better location and identification of the separated components.