Analytical Studies on Thiopyrazolone Derivatives. XI. Solvent Extraction of Metal Ions with Thiopyrine and Its Application to the Chelatometric Titration

Abstract

Solvent extraction of semimicro amount of metal ions with thiopyrine-metal-anion complexes was examined. Ag⁺, Pb²⁺, Cu²⁺, Zn²⁺, Co²⁺, Cd²⁺, Hg²⁺, and Bi³⁺ react with thiopyrine in the presence of univalent anions, such as thiocyanate, perchlorate, iodide, bromide, chloride, nitrate, or acetate to form the ternary complexes and are extracted quantitatively into chloroform. Ni²⁺, Mn^2+, Fe²⁺, Cr³⁺, Al³⁺, Mg²⁺, Ca²⁺, Sr³⁺, and Ba²⁺ are not extracted. This extraction is effective as a method for separation in the chelatometric titration of a mixture of metal ions.