Extraction of natural radionuclides from aqueous solutions by novel maltolate-based task-specific ionic liquids.

Two novel maltol-based ionic liquids, namely [A336][Mal] and [C101][Mal], were synthesized as potential extracting agents for radionuclides from water. These two room temperature task-specific ionic liquids could be easily prepared by anion metathesis starting from commercially available materials. The isolated compounds were characterized by standard analytical methods. Their application as extraction agent for Unat., 234Th, 210Pb, 210Bi, 210Po and 226Ra was elucidated by liquid-liquid extraction and scintillation counting. Uranium was totally extracted by both ionic liquids over a broad pH range (2-8), while the other radionuclides were removed with differing efficacies depending on the respective pH value.