Extraction Spectrophotometric Determination of Cobalt with β-Mercaptopropanoic Acid Anilide and its Applications

Department of Chemistry, University of Burdwan, Burdwan-713 104
Manuscript received 10 May 1984, revised 18 October 1985, accepted 15 November 1985

Small quantities (11-68 µg) of cobalt have been extracted Into chloroform as the 1 : 3 complex with β-mercaptopropanoic acid anilide from solutions of pH 5.3-10.5 con­taining ƴ-picoline The molar absorptivity of the red complex, measured at 480 pm is 1.33 x 10⁴ dm³ mol¹ cm¹ Cobalt has been determined in the extract with a relative standard deviation of ±1.6% The complex is stable upto two months and sufficient amounts of Zn^II, Me^II Mn^II, Ba^II, Ca^II, Sr^II, V^v, Ce^III, Mo^VI, W^vI, Na, K, chloride or nitrate are tolerated However, the separation from Be^II, Cu^II, Hg^II, Cd^II, Pb^II, Sn^II, Al^III, Co^III, Fe^III_, Bi^III, As^III, or Th^IV, or U^vI has been effected using suitable masking agents. For the determination of the composition of the complex, solid complex has been isolated and elemental analysis magnetic measurements and it spectral studies have been performed. The method has been used to determine cobalt in ores, alloys and medicinal samples.