The use of supercritical fluids in analytical chemistry is still grow ing. More and more analysts are discovering the favorable advan tages for a number of applications. Especially supercritical fluid extraction (SFE) has attracted a lot of interest in recent years due to its simplicity. Supercritical fluid chromatography (SFC) has become better established and the development of this technique has been accelerated by the many applications with capillary col umns which have been published in the literature. At first SFC equipment was based on instruments commonly used for liquid chromatography, and the first commercial in struments were derived from this technology. However, capillary columns can be much more easily interfaced to gas chromatogra phy equipment especially to the detectors commonly used for Oc. Many stationary phases both for packed micro columns and capillary columns have been designed for SFC purposes extending this technology to LC and OC. The most common fluid applied in SFC and SFE is carbon dioxide. The advantages of supercritical CO , such as having dif 2 fusivity like a gas and solvating power depending on temperature and pressure, are also valid for other fluids and modified fluids. Both properties are valuable for sample extraction and extraction selectivity.
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ISBN-13
978-3-642-77474-4 (9783642774744)
DOI
10.1007/978-3-642-77474-4
Schweitzer Klassifikation
1 SFC and SFE: An Introduction for Novices.- 2 Physico-Chemical Principles of Supercritical Fluid Separation Processes.- 2.1 Introduction.- 2.2 Physico-Chemical Properties of Pure Supercritical Solvents.- 2.3 Phase Equilibria of Fluid Mixtures.- 2.4 Physico-Chemical Applications of Sfc.- References.- 3 Basic Principles of Analytical Supercritical Fluid Extraction.- 3.1 The Development of Analytical SFE.- 3.2 Fluid Properties in SFE.- 3.3 Optimizing Experimental Conditions For Analytical SFE.- 3.4 The Relevance of Sfc-Derived Data To Analytical SFE.- 3.5 The Practice of Analytical SFE.- 3.6 Sample Matrix Effects in SFE.- 3.7 Problems and Future Research Needs in Analytical SFE.- References.- 4 Coupled Supercritical Fluid Extraction-Capillary Gas Chromatography (SFE-GC).- 4.1 introduction.- 4.2 Performing SFE-GC.- 4.3 Abilities and Limitations of Split and On-Column SFE-GC.- 4.4 Summary.- References.- 5 Gradients in SFC.- 5.1 Overview.- 5.2 Temperature Gradients.- 5.3 Pressure Gradients.- 5.4 Density Gradients.- 5.5 Velocity Gradients.- 5.6 References.- 6 injection Techniques in SFC.- 6.1 introduction.- 6.2 The Physical State of The Sample.- 6.3 introduction of Supercritical Fluid Extracts.- 6.4 introducing a Solution.- 6.5 Peak Focusing.- 6.6 Direct injection.- 6.7 Open Split (Dynamic Split) injection.- 6.8 Timed Split injection.- 6.9 Solvent Effects on Peak Shape.- 6.10 Solvent Venting with A Precolumn.- 6.11 Solvent Backflush.- 6.12 Solvent Venting with Gas Purging.- 6.13 Sample Losses in The injector.- References.- 7 Stationary Phases For Packed Column Supercritical Fluid Chromatography.- 7.1 introduction.- 7.2 Physical Properties of Column Packings.- 7.3 influence of Substrate Morphology on The Properties of Chemically Bonded Phases in SFC.- 7.4 influence of SurfaceHeterogeneity on The Properties of Chemically Bonded Phases.- 7.5 Macroporous Polymeric Packings.- 7.6 Column Packings Used For Special Applications.- 7.7 Conclusions.- References.- 8 Enantiomer Separation By Capillary Supercritical Fluid Chromatography.- 8.1 introduction.- 8.2 General Aspects.- 8.3 Packed Column SFC.- 8.4 Open Tubular Column SFC.- 8.5 Conclusion.- References.- 9 Supercritical Fluid Chromatography/Mass Spectrometry.- 9.1 introduction.- 9.2 Early investigations of SFC/MS.- 9.3 SFC/MS Using Direct introduction interfaces.- 9.4 SFC/MS Using High-Flow-Rate interfaces.- 9.5 Supercritical Fluid injection/Mass Spectrometry.- 9.6 Conclusion.- References.- 10 Supercritical Fluid Chromatography with FT-IR Detection.- 10.1 introduction.- 10.2 Flow Cell Approach.- 10.3 Solvent Elimination Approach.- 10.4 Summary.- References.- 11 Supersonic Jet Spectroscopy with Supercritical Fluids.- 11.1 introduction.- 11.2 Supersonic Jet Spectroscopy.- 11.3 High Pressure Fluid injection For Nonvolatile Samples.- 11.4 Supercritical Fluid Chromatography and Supersonic Jet Spectroscopy.- 11.5 Conclusions.- References.- Basic References Analytical Scale SFC/SFE.- Recommended Literature.
