A selective extraction by means of two-step supercritical CO2extraction was developed. This technique is based on the difference between the recoveries of organic compounds depending on fluid conditions such as temperature and pressure. Compounds with relatively high vapor pressure (alkanes) are easily extracted even at low temperature and pressure, whereas PAHs with very low vapor pressure are extracted only in the case of high temperature and pressure. Employing this difference, two-step extraction was successfully applied for selective extraction of alkanes and PAHs from coal flyash. Furthermore, a combined system of SFE and on-line mass-selective detection was devised and developed. This system is expected to be a powerful analytical technique with features of high-throughput and low-contamination.
Supercritical Fluid Extraction, Selective Extraction, Fly Ash, SPM