SYNERGIC EFFECT OF TRIPHENYLPHOSPHINE OXIDE (TPPO) ON THE EXTRACTION OF HG(II), SE(IV), CO(II) AND MN(II) WITH FLUORINATED PYRAZOLONE (HPMTFP)

Extraction of Hg(II). Se(IV), Mn(II) and Co(II) has been carried out with 1-phenyl-3-methyl-4-trifluoreacetyl-2-pyrazolin-5-one (HPMTFP) and triphenylphosphine oxide (TPPO) into chloroform from pH 1-10. Quantitative extraction of Hg(II), MN(II) and Co(II) at pH 4 with equimolar 0.05M (PMTFP + TPPO) in chloroform was observed. Se(IV) remains unextracted at this pH range. The stoichiometric composition of the extracted complexes M(PMTFP)2 . nH2O (M = Mn, Hg), M(PMTFP)2 . 2TPPO (M = Mn and Co) and Co(PMTFP)2 . TPPO . H2O at less than 0.1M TPPO has been established. The formation constants K(m,0) and K(m,n) and stability constants beta(m,n) have been computed. The analytical method developed was applied to the IAEA standard reference material (SRM) potato fluor V-4 for the determination of these elements using NAA technique.