POTENTIAL AND APPLICATIONS OF PRESSURIZED HOT WATER EXTRACTION

摘要

Pressurized hot water extraction (PHWE) is a relatively new analytical technique for the extraction of semivolatile and non-polar or medium polar organic compounds from solid sample matrices. Many other terms such as subcritical water extraction, superheated water extraction, extraction using hot compressed water, extraction with water at elevated temperatures and pressures and high temperature water extraction have also been used to describe this extraction method. The term pressurized hot water extraction (PHWE) is preferred here and limited to extractions where temperature is higher than 100℃ but lower than T_c. In addition to liquid water, steam is often used in PHWE and at high temperatures (>100℃). Also steam needs to be pressurized if it is to be efficiently pumped through the sample. A back pressure generated by the sample and PHWE instrument is in practice limiting the useable temperature range with steam.