Extraction of various metal ions from nitric acid to n-dodecane by diglycolamide (DGA) compounds

The extraction of various metals by N,N,N',N'-tetraoctyldiglycolamide (TODGA) from nitric acid to n-dodecane was investigated. It was obvious that divalent Ca (ionic radius: 100 pin), trivalent and tetravalent ions with ionic radii of 87-113 and 83-94 pin are highly extractable by TODGA. The limits of metal concentration (LOC) for Ca(II), Nd(III) and Zr(IV) in the extraction solvents, TODGA/n-dodecane, TODGA-DHOA(N,N-dihexyloctamide)/n-dodecane, TDDGA (N,N,N',N'-tetradecyldiglycolamide) and TDdDGA (N,N, N',N'-tetradodecyldiglycolamide) were determined. It is evident that LOC is influenced strongly by and increases with DHOA concentration and the length of alkyl chain attached to N atom of DGA.