Shawket Kadhim  Jawad, Musa Umran  Kadhium, Ebaa Adnan  Azooz, 
    Application Cloud Point Extraction Method Joined with Liquid Ion Exchange for Selective Determination of Fe<sup>3+</sup> and Hg<sup>2+</sup in Real Samples,
    Journal of Engineering and Applied Sciences,
    Volume 14,Issue 11,
    2019,
    Pages 3514-3521,
    ISSN 1816-949x,
    jeasci.2019.3514.3521,
    (https://makhillpublications.co/view-article.php?doi=jeasci.2019.3514.3521)
    Abstract: By using two approaches cloud point extraction technology CPE and liquid ion exchange to separate
and extracted Fe(III) and Hg(II) ions from acidic HCl media as ion pair association complexes by using new
laboratory prepared 2-(4-hydroxy phenyl azo)-4-benzene naphthol (HPBN) whereas the spectrophotometric
studies show the new organic reagent (HPBN) have a wave length for maximum absorbance was &lambda;<sub>max</sub> = 450 nm, the ion pair association complex of Fe<sup>3+</sup>  &lambda;<sub>max</sub>= 477 nm but for Hg<sup>2+</sup> &lambda;<sub>max</sub>= 476 nm, so that, the optimum condition for high extraction efficiency was 0.5M HCl for both ions ,100 &mu;g metal ions in 10 mL aqueous solution 1&times;10<sup>-4</sup> M of HPBN and necessary to heating the solution at 90&deg;C for 20 min to Fe<sup>3+</sup> ion and 15 min. For Hg<sup>2+</sup> ion and
in presence of 0.5 mL Triton X-100 for Fe<sup>3+</sup> and 0.8 mL Triton X-100 for Hg<sup>2+</sup> ion. As well as the research
involved other studies such as electrolyte effect interferences effect, stoichiometry, application and
determination of trace amounts of Fe(III) and Hg(II) in environmental sample by spectrophotometry.
    Keywords: Cloud point extraction;liquid ion exchange;2-(4-hydroxy phenyl azo)-4-benzene naphthol (HPBN);mercury;iron;Hg(II)