Supercritical Fluid Technology in Analytical Chemistry - Review

This review provides an updated discussion on the recent developments and applications of supercritical fluid technology in analytical chemistry. Supercritical mediums are usually used for extraction and separation of various analytes in analytical science. Although, this technology is used for chromatographic aims in the analysis of various samples the main application domain of supercritical fluids is in extraction process. SFE is suitable for recovery of various analytes, especially non-polar organic compounds, from different matrices. However, via some modifications or by the aid of modifiers or a chelating agent, this technique could be successfully applied in the extraction of polar or even ionic analytes. The range of analytes extracted via SFE is wide and mostly includes food and pharmaceutical samples, pollutants extraction and metal cation extraction. The aim of this paper is to review, from analytical chemistry standpoint, recent advances in the use of SC-CO2 for the extraction and separation of analytes. At the same time, a critical assessment will be made of the advantages of SCF technology in comparison with traditional methods. Special emphasis will be given to online coupling of SFE method with chromatographic techniques and FT-IR spectroscopy that make possible the extraction and separation of various analytes from different matrices in order to produce novel analytical techniques. The potentials, advantages, shortcomings, and prospects in employment of supercritical fluids for separation and extraction of various analytes are also considered. The efficiencies of SFE for the extraction of various analytes from solid and aqueous samples are compared to traditional methods such as Soxhlet extraction. Supercritical fluid extraction due to various reasons such as its greenness, rapidity and high efficiency are widely used an alternative to conventional solvent-based extraction methods. Also, SFE can be as an automated and miniaturized extraction technique, since it reduces the amounts of required samples considerably. SFE avoids multi-steps of conventional methods (such as partitioning, clean-up, evaporation) and hence it can reduce the uncertainty in the results. Furthermore, SFE reduces analysis times and is less laborintensive.