Titrimetric determination of microgram amounts of silver by thiocyanate amplification after precipitation as silver hexathiocyanatochromate(III)

Abstract Silver (25–300 μg) is precipitated as Ag 3 [Cr(SCN) 6 ]. The precipitate is collected and then treated with 10% sodium carbonate solution, and the thiocyanate dissolved is oxidized to sulfate by iodine at pH 8.2. After acidification, the excess of iodine is extracted into chloroform, and the iodide in the aqueous solution is determined by the Leipert amplification procedure. The method provides 76 iodine atoms for each original silver ion, and only Cu 2+ interferes seriously.