Extraction Spectrophotometric Determination of Bismuth(III) with Iodide and Amidines

Abstract A new simple and rapid spectrophotometric method for the extraction and determination of bismuth(III) is described. The reaction of N,N′-diphenylbenzamidines and its 10 derivatives (HA) with bismuth(III) in presence of iodide have been investigated photometrically in chloroform. The value of molar absorptivity of the complexes with these compounds lies in the range (0.84–1.35)×104 l mol−1 cm−1. Of these, the most sensitive compound N-(2-methylphenyl)-N′-phenylbenzamidine hydrochloride (MPPBA) was selected for detailed studies. The detection limit of the method is 0.2 μg Bi cm−3. The elements which are commonly associated with the metal e.g. Cu, Ni, Co, Mn, Cr, Zn, Hg, Ti, Zr, Mo, W, V, Al, Sb, etc. do not interfere. The method has been applied for the determination of the metal to soil and ore.