SOLVENT-IMPREGNATED RESINS CONTAINING DI-(2,4,4-TRIMETHYLPENTYL)PHOSPHINIC ACID .1. COMPARATIVE-STUDY OF DI-(2,4,4-TRIMETHYLPENTYL)PHOSPHINIC ACID ADSORBED INTO AMBERLITE XAD-2 AND DISSOLVED IN TOLUENE

Solvent-impregnated resins (SIR) containing di-(2,4,4-trimethylpentyl) phosphinic acid (DTMPPA) were prepared by adsorption of the organophos phorus extractant into Amberlite XAD-2 polymeric macroporous support. The distribution of DTMPPA between the aqueous phase and resin phase w as determined as a function of both pH and loading of the organophosph orus extractant on the resin. The distribution ratio of the organophos phorus compound was obtained after determining the total phosphorus co ncentration in the aqueous phase by coupled plasma atomic emission spe ctroscopy. The data were analyzed numerically by the program LETAGROP- DISTR, in order to determine the distribution constant K(D), the aggre gation constant K(n) and the acidity constant K(a). Moreover, in order to clarify the interactions between the polymeric adsorbent and the e xtractant, Fourier transform infrared spectroscopy studies have been c arried out. Finally the distribution of DTMPPA dissolved in toluene ha s been compared with its distribution in Amberlite XAD-2.