Supercritical Fluid Extraction and its Use in Chromatographic Sample Preparation, Softcover reprint of the original 1st ed. 1993

by Professor D. E. Games, Mass Spectrometry Research Unit, University College of Swansea Sample preparation can be viewed as occupying a Cinderella role in analytical science. However, the quality of sample preparation plays a key role in high In the past decade, there has been quality analysis and deserves higher stature. considerable interest in the use of supercritical fluid extraction (SFE) as an alternative to conventional procedures for the preparation of samples for ana­ lysis. The driving force for this development is the need for automated, sim­ pler, faster, non-destructive and selective methods for extraction, preferably using non-toxic extraction media which are easily disposed of. Utilization of supercritical fluids for extraction fulfils these requirements because of their unique physical chemical properties and usually low toxicity. Selectivity can be achieved by suitable selection of pressure (density), temperature and modi­ fier conditions which enable solvating power to be varied. The high diffusivity of supercritical fluids provides rapid sample penetration and extraction. Use of fluids with low critical temperatures enables extraction to be conducted under mild thermal conditions ensuring that thermally labile compounds do not decompose. The technique can be used off-line, and the extracts analysed by appropriate techniques, or it can be used on-line, by coupling with a variety of chromatographic techniques. These can then, if necessary, be coupled fur­ ther with spectroscopic techniques, such as Fourier transform infrared, ultra­ violet or mass spectrometry, to provide specific identification or structural information.

1 Introduction to supercritical fluid extraction in analytical science.- 1.1 Introduction.- 1.2 Extraction controlled by diffusion out of the matrix.- 1.3 Equations for discontinuous extraction.- 1.4 Extraction controlled by both solubility and diffusion.- 1.5 Solubilities in supercritical fluids.- References.- 2 Methodology for off-line supercritical fluid extraction.- 2.1 Introduction.- 2.2 The off-line SFE experiment.- 2.3 Instrumental considerations.- 2.4 Supercritical fluids and modifiers.- 2.5 Developing an off-line SFE method.- 2.6 New directions in off-line analytical SFE.- 2.7 Summary.- References.- 3 Coupled (on-line) supercritical fluid extraction-gas chromatography.- 3.1 Introduction.- 3.2 Generalized approaches to SFE-GC coupling.- 3.3 Performing direct injection on-line SFE-GC.- 3.4 Summary.- References.- 4 Coupled supercritical fluid extraction-capillary supercritical fluid chromatography.- 4.1 Introduction.- 4.2 Samples for which SFE-CSFC is applicable.- 4.3 Influence of the sample matrix.- 4.4 Instrumentation.- 4.5 Trapping procedures.- 4.6 Optimization of conditions for SFE-CSFC.- 4.7 Selected applications of SFE-CSFC.- 4.8 Conclusions.- References.- 5 Supercritical fluid extraction coupled to packed column supercritical fluid chromatography.- 5.1 Introduction.- 5.2 Packed vs. capillary columns.- 5.3 SFE coupled to packed column SFC.- 5.4 Instrumental aspects.- 5.5 Applications.- 5.6 Future prospects.- References.- 6 Supercritical fluid extraction-high performance liquid chromatography: on-line and off-line strategies.- 6.1 Introduction.- 6.2 On-line studies.- 6.3 Off-line studies.- 6.4 Conclusions.- References.

Provides not only an informative text but a practical experimental guide to the theory and practice of SFE as an analytical sample preparation tool. - Analyst, Provides an excellent introduction to this new and exciting field of analytical SFE. - Analytica Chimica Acta, Gives a useful description of the current situation and, importantly, describes some of the pitfalls and problems that may be encountered ... useful as a summary for workers already in the field and a valuable introduction for any analyst considering using SFE. - Chromatographia, ...very useful for those willing to introduce this technique in their laboratory. All chapters are well developed with many applications showing that SFE is conquering the procedures. Therefore, each analyst who works or will work with SFE, should have this book in his/her library. - European Journal of Pharmacology and Biopharmacology