Application of off‐line supercritical fluid extraction—gas chromatography for the investigation of chemical constituents in Curcuma zedoaria

Analytical supercritical fluid extraction (SFE) was used to investigate the chemical constituents of Curcuma zedoaria , a very useful Chinese herbal medicine. The qualitative and quantitative analysis of extracts was performed by gas chromatography with mass spectrometry. The effects of pressure, temperature and flow rate of the extracting fluid on the extraction efficiency of SFE were investigated quantitatively. It was found that at a fixed density, changing temperature in a given experimental range had no great influence on the distribution of SFE products, but that an appropriate increase of flow rate and fluid volume improves the extraction efficiency. SFE using supercritical carbon dioxide was a more efficient extraction technique than steam distillation.