ESI-MS speciation analysis of neodymium and thorium complexed with nitrilotriacetic and picolinic acids

We contributed to the speciation analysis of PA complexes with Ln and An, for which published studies are very scarce. Th-PA species with stoichiometries 1:1, [ThPA]3+ to 1:6, [ThPA6]2− were observed. The 1:1 species showed its prevalence under most conditions studied. PA showed to form complexes with Nd with stoichiometries 1:1, [NdPA]2+ to 1:4, [NdPA4]−. The 1:3 species seems to gain dominance as PA concentration increase. Speciation analysis of Th and Nd with mixtures of ligands and in a spiked real sample is also presented.