Studies of the extraction of zinc by pyridine 2-aldehyde-2′-pyridylhydrazone (paphy) in chloroform

The distribution of zinc between solutions and pyridine 2-aldehyde-2′-pyridylhydrazone (PAPHY) in chloroform has been studied as a function of the pH of the aqueous phase and the concentration of PAPHY. Stability and acid dissociation constants of the complex ions have been determined as well as the partition coefficients of the ligand and its extractable zinc complex. An equation has been proposed to represent the extraction equilibria and its essential correctness varified.