Trace analysis in capillary supercritical fluid chromatography: Sample introduction

Abstract

When capillary columns were introduced in supercritical fluid chromatography (SFC) a decade ago, the separation power of SFC increased considerably. The sample introduction systems which were developed at the same time were, however, mainly based on sample splitting, which leads to problems in trace analysis. In recent years considerable effort has been channeled into the development of injectors where the solvent is removed prior to the column. In addition to methods for injection in solvents, which are treated in this article, advances in coupled supercritical fluid extraction (SFE—SFC) have helped to convert SFC into another technique for trace analysis, to complement gas chromatography and liquid chromatography.