Supercritical fluid extraction in herbal and natural product studies - a practical review

Due to increasingly stringent environmental regulations, supercritical flui d extraction (SFE) has gained wide acceptance in recent years as an alterna tive to conventional solvent extraction for separation of organic compounds in many analytical and industrial processes. In the past decade, SFE has b een applied successfully to the extraction of a variety of organic compound s from herbs and other plants. This review article presents the practical a spects of SFE applications in sample preparation, selection of modifiers, c ollection methods, on-line coupling techniques, means for avoiding mechanic al problems, and approaches to optimization of SFE conditions. SFE can also be used to clean up pesticides from herb medicines. SFE processes can be m odeled to acquire useful information for better understanding of the extrac tion, mechanisms and optimization of the extraction procedures. With increa sing public interest in natural products, SFE may become a standard extract ion technique for studying herbal, food and agricultural samples. (C) 2001 Elsevier Science B.V. All rights reserved.