ABSTRACT
This chapter highlights selection of mobile and stationary phases, important theoretical considerations, selection of the best injection technique for an application, important practical aspects, optimisation of separation conditions, and control of linear velocity and detection parameters and interfacing. Nitrous oxide has been found to elute aliphatic and aromatic amines more easily than carbon dioxide on both packed and capillary columns. Pure fluids which are more polar than carbon dioxide and have been tested to date include ammonia, sulphur dioxide, chlorofluorocarbons and fluorocarbons. Small changes in pressure cause a large change in density and hence if pressure is programmed linearly at constant temperature. The restrictor is one of the key parts of a capillary supercritical fluid chromatography (SFC) system, and must be properly operated in order to optimize chromatographic performance. Solvent venting is a technique used to inject larger volumes of sample into the SFC in comparison to the split injection techniques and hence detection limits can be improved.
