APPLICATION OF SUPERCKITICAL FLUID EXTRACTION IN QUALITY CONTROL OF CHINESE MEDICINAL MATERIALS

This study indicates that supercritical fluid extraction ( SFE ) can be adopted jnstead of traditional solvent extraction to extract the active constituent indirubin in Chinese medicinal materials(Strobilanthes cusia,Isatis tinctoria and Polygonum tinctorium).A two-level , two- factor(2²) factotial design approach is used to optimize the temperature and pressure in SFE.A systematic method is also used to optimize five variables(temperature , pressure , modifier concentration , static extracting time and CO₂ dynamic extracting volume)of SFE. The results demonstrate the utility and efficiency of factorial design in two-level , two-factor(2²)for optimizing SFE temperature and pressure , and also show faster extraction kinetics and the ability of SFE to vary the extracting power through adjustments of the above five variables.Sample extracts were analyzed bymicrobore high performance liquid chromatography(MHPLC).The method showed good linearity(r=0.9998,n=5)in the range of 2.11～10.57 μg·ml^-1 of indirubin.The average recovery was 94. 63%with RSD<0. 92%(n=4). MHPLC condition : column : Spherisorb 3μm,C₁₈( 1 mm × 1 5 0 mm);mobile phase : methanol-water(7:3);flow rate : 40μl·min^-1;UV detection : 290 nm;recorder sensitivity: 0. 01 AUFS; injection volume : 0.1μl.