Supercritical fluid techniques

Liquid phase chromatography can use a supercritical fluid as an eluent. The solvent evaporates on leaving the column and allows detection by FID. At present, there are few instances in the petroleum industry using the supercritical fluid technique. 

Supercritical Fluid Techniques Coupled with Chromatographic Techniques... 

Jarvenpaa, E.P., Rostiala, N., and Huopalahti, R., Utilization of supercritical fluid techniques in the fractionation of natural pigments, in Proceedings of 3rd International Congress on Pigments in Food, Le Berre, Quimper, France, 2004, 29. 

Table 3.11 Critical parameters for some fluids used in analytical supercritical fluid techniques (data taken from SF Solver package, Isco, USA)...

On-line SFE-SFC modes present several distinct advantages that are beyond reach of either technique when used separately (Table 7.13). An obvious advantage of SFE is that it is an ideal way to introduce a sample into an SFC system. Because the injection-solvent is the same as the mobile phase, in this respect the criteria for a successful coupling of different techniques are fulfilled [94], i.e. the output characteristics from the first instrument and the input characteristics of the second instrument are compatible. Supercritical fluid techniques can separate high-MW compounds are significantly faster than classical Soxhlet extractions and require less heat and solvent. SFE-SFC techniques are versatile,... 

Purification. Where an aqueous system or aqueous purification is employed, water can be left with traces of organic solvents, such as toluene, which may prohibit river disposal. Supercritical-fluid techniques can be used for final purification. 7 8... 

The most important advantages of the supercritical fluid technique in the application to pharmaceuticals is the high quality of the products in terms of purity, their unique morphology, and the wide range of materials that can be processed. Furthermore, the mild operating conditions can be especially favourable to bio-labile molecules, such as protein- or genetic material involved in pharmaceutical applications. 

Aymonier C, Cansell F. Supercritical fluid techniques. Annales De Chimie-Science Des Materiaux. 2006 31(3) 317-337. 

A. Staby, Application of Supercritical Fluid Techniques on Fish Oil and Alcohols, Dissertation, Lyngby, Denmark 1993... 

Feeley JC, York P, Sumby BS, Dicks H, Hanna M. In vitro assessment of salbutamol sulphate prepared by micronisation and a novel supercritical fluid technique. Drug Delivery Lungs 1998 IX 196-199. 

Table 3 Drug-Containing Polymeric Microparticles Prepared by Using Supercritical Fluid Techniques...

Hopper, M. L. (1997). Extraction and cleanup of organochlorine and organophosphonis pesticide residues in fat.s by supercritical fluid techniques. J. AOAC Inl. 80, 639-646. 

Martin Del Valle, E.M. Galan, M.A. Supercritical fluid technique for particle engineering Drng delivery applications. Reviews in Chemical Engineering 21(1), 33-69, 2005. 

Figure 19. Phospholipid enrichment/fractionation by supercritical fluid techniques.

Supercritical fluid technique Supercritical fluids are dense as liquids but have viscosity as low as that of gas. In this technique, a solution of the drug efficiently swells the matrix the solvent is then easily removed by decreasing the pressure, leaving the drug behind in the matrix [65]. 

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