SUPERCRITICAL-FLUID EXTRACTION - A NEW PE RFORMANT ANALYTICAL TOOL FOR SAMPLE TREATMENT

Advantages of supercritical fluid extraction (SFE) over classical meth ods of sample preparation (rapidity, selectivity, low consumption of s olvent, easiness of automation) are at the origin of its rapid develop ment during the last years. For a given solute, the extraction recover y depends on the characteristics of both the supercritical fluid state (temperature, pressure, density, presence of polar modifier) and the matrix (texture, water content, particule size). A particular attentio n must always be paid to the system of collection of extracted solutes . It is necessary, before making supplementary studies, to check thai the recuperation of solutes is quantitative. The study of the influenc e of flow-rate on the extraction recovery allows the determination of the extraction-rate limiting process and, therefore, the optimization of the extraction. Recent applications of SFE in the field of environm ental, food, biological and polymeric matrix are reported.