Komplexone XXX. Diäthylentriamin-pentaessigsäure (DTPA)†

Diethylenetriamine-pentaacetic acid (DTPA) forms with metal cations Mv+ the complexes MZv−5; MHZv−4, M2Z2v−5, where Z5− stands for the anion of DTPA. Complexes MM′Zv1 + V2 −5 containing two different metals are also formed. The stability constants of these species with Ca, Mn, FeII, FeIII, Co, Ni, Cu, Zn, Cd, Pb, Hg, Ce have been determined, using 7 methods. The DTPA-complexes are considerably more stable than the corresponding EDTA-complexes which makes DTPA a considerably better titrant in complexometry.