Analytical extractions with water at elevated temperatures and pressures

Water can be used effectively as solvent in pressurized hot water extraction (PHWE) because the physico-chemical properties of water are readily altered through changes in temperature and pressure. Temperature is the main parameter affecting extraction, but time and flow rate are also essential in solubility-limited extractions. PHWE has been applied to a variety of analytical extractions (e.g., organic pollutants, pesticides, flavors, fragrances, and metals). PHWE has often shown similar or better extraction recoveries and efficiencies than many conventional methods (e.g., Soxhlet, accelerated solvent extraction and supercritical fluid extraction). PHWE systems can easily be coupled to chromatographic separation (e.g., LC or GC). (C) 2007 Elsevier B.V. All rights reserved.