| Supercritical fluid extraction (SFE) is environmentally friendly and high effective technology. It has been presently considered as analytical extraction method and has been proposed as an alternative approach for analyzing harmful chemical residues in biological samples. It has been also considered as one of the most attractive technology for processing natural product and traditional China medicines (TCM). In this thesis, analytical SFE was used for determination of the harmful organotin compounds (OTCs) in foods, and industrial SFE was used for extraction of active components from codonopsis pilosula. The two kinds of projects are important in the fields of food safety and modernization of TCM.A rapid and green method for the determination of six OTCs, namely trimethyltin chloride (TMT), butyltin trichloride (MBT), dibutyltin dichloride (DBT), tributyltin chloride(TBT), triphenyltin chloride (MPT) and phenyltin trichloride(TPT), in clam samples was established by combining SFE and headspace solid-phase microextraction (HS-SPME) as pretreatment method and then by gas chromatography with mass spectrometry (GC-MS) analysis. Effect of some factors on extraction efficiency was investigated and the optimal operation parameters were obtained as follows. The clam sample was first extracted at 45℃and 30 MPa with supercritical carbon dioxide in presence of 5% (mol) methanol at 1.2 L·min-1 (as carbon dioxide in ambient pressure) for 15 min. The SFE extract was then ethylated with 0.02 g·mL-1 sodium tetraethylborate (NaBEt4) in pH 4 buffer solution and simultaneously adsorbed by HS-SPME with polydimethylsiloxane / divinylbenzene (PDMS/DVB) fiber at 50℃for 30 min. And then GC-MS was performed. The whole process for sampling and analyzing was within 1h, and only less than 10 milliliters of organic solvent was used. Six OTCs in the spiked clam sample were determined with the established method, in which the recoveries of DBT,MPT,TBT and TPT were from 79 % ~ 90 % with LOD ranging from 0.04 to 0.26 ng/g, which indicate that the established procedure in this paper should be reliable and accurate for the determination the four OTCs in biotic sample. However, the established method may not suitable for determination of TMT and MBT as their recoveries were between 26% and 63%.A semiflow-type, dynamic apparatus was established for determinating the solubility of compounds in supercritical fluid. An equipment reliability proof test was made with the benzoic acid-carbon dioxide system. Comparing the measured benzoic acid solubility data with literature data, the average deviation is within 5%. The solubility of TPT and triphenylmethyl chloride (TPC) in supercritical CO2 were measured at a temperature ranging from 308.15 K to 338.15 K and various pressures in the range of 15 MPa to 40 MPa. The mole fraction solubilities ranged from 4.12×10-4 ~1.10×10-3 for TPT, and 3.82×10-4 ~ 2.70×10-3 for TPC. The experimental data of the solubility of TPT and TPC were correlated by Gordillo equation, Chrastil equation and modified Chrastil models separately, and good fit results were obtained. The correlation errors of the three models for TPT are 5.0%, 8.6% and 7.1 % respectively. And the correlation errors of the three models for TPC are 11.4%, 6.4% and 7.3% respectively.Finally, supercritical extraction of active compounds from Codonopsis pilosula with CO2 was studied. The influences of particle size, pressure and temperature on yield together with the yield of total sapogenins were discussed, Based on one-factor-at-a-time experiments. The optimal yield of 0.0111g·g-1 and yield of total sapogenins 2.23 mg·g-1 were obtained, when Codonopsis was extracted at 30 MPa, 65℃and 2 L·min-1 (as CO2 in normal pressure and temperature) for 2 hours with pure supercritical Carbon Dioxide. To develop a green and rapid method for extraction of lobetyolin from Codonopsis pilosula, extraction of lobetyolin from Codonopsis pilosula with supercritical carbon dioxide in the presence of ethanol was studied. The effect of pressure, temperature, volume of cosolvent and extraction time on efficiency and their interactive relationships were discussed, based on central composite design and response surface methodology (RSM). The key factor, volume of cosolvent was found. The extraction yield of lobetyolin was 0.0786 mg·g-1 when Codonopsis pilosula was extracted at 30 MPa, 60℃and 2 L·min-1(as CO2 in normal pressure and temperature) for 100 minutes with supercritical CO2 and 1 mL·min-1 ethanol as dynamic cosolvent. This result is better than that obtained from ultrasonic method. Therefore, the optimized process is a valuable method for extraction of lobetyolin from Codonopsis pilosula.
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