Cloud-Point Extraction: Theory and Applications of Surfactants in Analytical Chemistry

Abstract

Cloud-point extraction is the extraction and preconcentration of target analytes using surfactants as extractant such as non-ionic and anionic surfactants etc. Under the optimum conditions including temperature, pressure, concentration of surfactant and salt, the aqueous surfactant solution becomes clouding and separating into two phases (i.e., aqueous and surfactant-rich phases). The target analytes are extracted and concentrated into surfactant-rich phase. The cloud-point extraction is simple, rapid, high extraction efficiency and environmentally friendly. This review includes theory and principle of cloud-point extraction as well as its application for the analysis of various analytes.