There has been a great interest on

There has been a great interest on the use of aqueous micellar
solution in thefield of separation science in recent years. At certain
temperature, aqueous solution of a non-ionic surfactant becomes
turbid. With further increase of temperature, solution separates in
two phases;first is the surfactant rich phase, which has a small volume
compared to the solution and is called the coacervate phase and the
other, is the bulk aqueous solution containing surfactant concentration
slightly above the critical micelle concentration (CMC). This temperature is known as the cloud point temperature (CPT) of the surfactant.
The solute present in the aqueous solution of non-ionic surfactant is
distributed between the two phases at the cloud point temperature.
This phenomenon is known as cloud point extraction (CPE). Cloud point
extraction using micelles or mixed micelles is a very promising
methodology for the establishment of new analytical procedures
[14–18]. The small volume of the surfactant-rich phase obtained by
using the cloud point methodology permits to design an extraction
strategy presenting robustness, low cost, good extraction efficiency and
lower toxicity than those using organic solvents. Environmental
pollution is limited due to using only a small amount of surfactant[19]