Abstract:
The use of impure D2EHPA in solvent extraction of metal ions leads to many process problems. Analysis of the quality of D2EHPA before use is warranted. The titrimetric estimation of D2EHPA containing M2EHPA of various samples in 50% (v/v) aqueous ethanol was studied using visual colour indicators. Bromophenol blue, methyl orange, methyl red, 2,4-dinitrophenol and bromocresol green indicators were tested for estimation of D2EHPA and M2EHPA together. To estimate the M2EHPA content, phenolphtalein, thymolphtalein, beta-naphthol violet and thymol blue indicators were tested. The use of methyl red in combination with phenolphthalein or thymolphthalein indicators gave comparable results with potentiometric titration.