Separation and preconcentration by cloud point extraction procedures for determination of ions: recent trends and applications

The cloud point extraction procedure is an alternative to liquid-liquid extraction and based on the phase separation that occurs in aqueous solutions of nonionic surfactants when heated above the so-called cloud point temperature. We review the more recent applications for determination of ions by means of this procedure for sample preparation over the range 2009 to first part of 2011. Following an introduction, the article covers aspects of cloud point extraction of one metal ion, two metals ions simultaneously, three metal ions simultaneously, multielement analysis, anions analysis, and online cloud point extraction. One hundred sixteen references are cited.