Showing papers on "NQS published in 1982"

Spectrophotometric Study on the Extraction of Cobalt and Iron Chelates of 7-Nitroso-8-Hydroxy-Quinoline-5-Sulphonic Acid with Zephiramine

Abstract: 7-Nitroso-8-hydroxyquinoline-5-sulphonic acid (H2 NQS) was used as a chelating reagent for ion-pair extraction of cobalt (II) and iron (II) with tetradecyl-dimethyl-benzyl-ammonium chloride (zephiramine = Z+Cl-). The ternary complexes, being charge transfer complexes, had the absorption maxima at 530pm for cobalt and at 695pm for iron. The optinum pH ranges for the extraction were 3.5-8.0 and 4.5-8.5 for cobalt and iron respectively. The compositions of the ternary complexes were Co(NQS)3 Z 3 and Fe(NQS)3 Z 4. In the presence of adequate amounts of sodium chloride, the excess of reagent in the organic phase can be removed into the aqueous phase. The exchange equilibrium constants for the metal complex anion and the chloride ion were calculated to be K3Cl−Fe(NQS)3 3=9.38 and K4Cl− Fe(NQS) 3 4= 8.39.