Cloud point extraction (CPE), also called micelle-mediated extraction, is based on the phase separation behavior exhibited by aqueous solutions of some surfactants,  usually nonionic, anionic, or zwitterionic. CPE has been recognized as an alternative approach to conventional liquid–liquid extraction because of a number of  advantages: low cost, environmental safety, short analysis time, simultaneous  pretreatment of a large number of samples is possible, and high recovery for a  wide variety of analytes. The cloud point phenomenon occurs when aqueous solutions of surfactants at concentrations above the critical micelle concentration  (CMC) associate to form molecular aggregates (micelles) upon modification of  temperature or pressure, or introduction of a suitable additive,