| Abstract: | A new analytical technique combining on-line supercritical fluid chromatography with capillary gas chromatography has been developed. The supercritical fluid sample effluent is decompressed through a restrictor directly into a conventional capillary gas chromatographic injection port. This technique allows for not only direct (100%) sample transfer from the supercritical fluid chromatograph to the gas chromatograph but also for selective or multi-step heartcutting of various sample peaks as they elute from the supercritical fluid chromatograph. Heartcut times are determined by monitoring the responses from the flame ionization or ultraviolet absorbance detectors on the supercritical fluid chromatograph. This report describes the operational setup and provides the results of heartcut reproducibility experiments using normal hydrocarbon and aromatic test mixtures. Results from studies where operational parameters were varied, such as GC injector temperature, will also be provided. The potential usefulness of this new technique for selective heartcutting will also be demonstrated using complex hydrocarbon streams. |
