Abstract: | Summary The reagent Bismuthiol II completely precipitates palladium at a maximum acidity of 0.3 N in nitric acid, 0.5 N in hydrochloric acid or 1 N in sulphuric acid and also at a maximum pH of about 8.0. The palladium complex Pd (C8H5N2S3)2 is stable even up to a temperature of about 250° C. From a mineral acid solution palladium can be estimated in presence of ions of Fe2+, Al, Cr, Th, Ce3+, Zr, Ti4+, UO2
2+, Be, Mn, Co, Ni, Mg, P04
3–, AsO4
3–, rare earths, alkalis, alkaline earths, Ce4+, WO4
2– and MoO4
2– that are not ordinarily precipitated by the reagent. At a pH of 4.75 to 8.2, EDTA, Na-salt, keeps in solution, besides the above ions, the ions of Tl+, Cu2+, Pb, Bi3+, As3+, Sb3+, Zn, Cd, Fe3+, CrO4
2–, AsO3
3– and VO3
–. Tartrate, however, at a pH 6.2–8, keeps all the ions including Sn4+ in solution except of course Tl+, Cu2+, Pb and Cd. Separation from Ce4+, WO4
2–, MoO4
2– and AsO4
3– at a low pH require the presence of tartrate. Ag+, Hg2+ and also Pb may be complexed with potassium iodide at a pH 6–8. Tl+ and Ag+ may also be separated in presence of cyanide in an acetate buffer when palladium remains in solution and from which it may be re-precipitated by acidification.Part II see Z. analyt. Chem. 154, 413 (1957). |