Feasibilities And Limitations Of Carbon Dioxide Supercritical Fluid Extraction, The Extraction Of Natural Products

Author

M. Marsin Sanagi1, Umi K. Ahmad1, and Roger M. Smith2 , 1Department of Chemistry, Universiti Teknologi Malaysia, 80990 Johor Bahru, Johor, Malaysia. 2Department of Chemistry, Loughborough University of Technology, LEI1 3TU, U.K.

Proceeding

Trends in Traditional Medicine Research, Proceedings of the International Conference on the Use of Traditional Medicine & Other Natural Products in Health Care

Date

8/6/1993

Keyword

Supercritical fluid extraction; Zingiberaceae; Curcuma longa Linne; Alpinia galanga Willd; Zingiber zerumbet Smith.

Abstract

Supercritical fluid extraction (SFE) offers fast and easy separation of the solvent from the extracts and coupled with the ease of fractionation of the components makes it a potentially powerful alternative to conventional liquid extraction methods. This paper describes recent works on the use of SFE in the extraction of natural products. Studies on SFE carried out in our laboratories have been focused on the extraction of compounds from the rhizomes of selected species of the Zingiberaceae family including Zingiber offcinale, Curcuma longa Linne, Alpinia galanga, and Zingiber zerumbet Smith. Supercritical fluid extractions of the samples using neat C02 under a mild temperature of 60°C and pressure of 100 bar yield largely the volatile, non-polar components. Limitation of the SFE of these natural products arose from the low solubilities of the polar components in C02. The addition of small proportions of a modifier solvent such as methanol will circumvent this problem but excessive organic modifier will decrease selectivity and it will be similar to liquid extraction. SFE of the samples followed by on-line trapping of the neat C02 extracts onto a silica column enables better fractionation of the extracts. Problems due to plugging of restrictors and loss of the more volatile components resulting in poor reproducibility are described.   Measures to tackle these problems will be discussed.