Abstrakt

Extractive Spectrophotometric Determination Of Cobalt(II) With 1-(Benzimidazol-2-Yl) Ethanone Thiosemicarbazone

K.Syamasundar, M.Adharvana Chari, D.Shobha

1-(Benzimidazol-2-yl) ethanone thiosemicarbazone is used as a chromophoric reagent for the extraction and spectrophotometric determination of Cobalt (II). Cobalt (II) forms 1:2 complexes with the reagent at pH 9.0. The 1:2 metal complex has λmax value at 388 nm. The Cobalt (II) thiosemicarbazone complex is stable for 72 h, with molar absorptivity of 5.89 x 103 lit mol-1 cm-1 and Beer’s law is obeyed in the range of 0.3 to 6.2 ug/ml. The effect of various foreign ions is also studied. The stability constant of the complex is determined.The method is applied for the determination of Cobalt(II) in medicinal samples and the results are compared with atomic absorption spectrophotometer.