Extraction of heavy metal ions from aqueous solutions into the <i>in situ</i> formed ionic liquids with subsequent determination by atomic emission spectrometry with microwave plasma

Ionic liquids based on quaternary ammonium cations – tetrahexylammonium dioctyl sulfosuccinates (THADOSS) and tetrabutylammonium are obtained in situ by mixing salts in an aqueous solution – suppliers of the cation and anion, constituting the ionic liquid, and studied for the extraction of heavy metal ions from aqueous solutions. Cd(II), Co(II), Cu(II), Ni(II), Pb(II), and Zn(II) ions are quantitatively extracted in the presence of 4-(2-pyridylazo)resorcinol (1 × 10–3 M) into the in situ formed THADOSS at pH 4.9 in 1 min. The possibility of determining metals by microwave plasma atomic emission spectrometry after extraction into ionic liquids is demonstrated; the detection limits are from 2 to 25 μg/L.