Precipitation separation of lead and calcium, strontium, barium from acidic solutions using crown ether and tungstosilicic acid

It was found that lend reacts with 18-crown-6 (L) and tungstosilicic acid (H(4)A) in acidic solutions and a compound with low solubility is formed what was confirmed by radiometric titration methods. Coprecipitation of complexion cation of PbL2+ with similar complexion cations of calcium, strontium and barium wets studied. Formation of law soluble salts was utilized for separation of Pb from Ca, Sr and Ba from 1 mol.dm(-3) HNO3. The ratio of Pb/Ca, Pb/Sr and Pb/Ba in the precipitation or separation factors S-Pb/M undoubted depends on the ratio of the stability constants of lead and metals with 18C6 (beta(Pb)/beta(M)), what call be used for determination of mure precise constant stability beta(M).