IMPROVED CHROMATOGRAPHIC RESOLUTION FOR GAS-CHROMATOGRAPHY MATRIX-ISOLATION INFRARED-SPECTROSCOPY

When gas chromatography/matrix isolation infrared spectroscopy (GC/MI-IR) is carried out with a fixed cryodisk rotation speed, chromatographic resolution may be substantially degraded. In this research, an approach allowing dynamic programming of disk rotation speed is shown to result in much improved resolution in reconstructed chromatograms. Use of up to 254 different speeds during a single chromatographic run is possible. Thus, the analyst can match the requirements of any specific separation problem with an appropriate set of cryocollector movement speeds. As a consequence, much improved analytical performance without loss of sensitivity is possible for mixture analysis by GC/MI-IR, as is up to 30% higher apparent chromatographic resolution than is observed with a flame ionization detector. In addition, careful matching of sample spot size and detector area with the appropriate cryodisk speed leads to the detection of as little as 40 picograms of hexachlorobenzene.