Simultaneous Second Order Derivative Spectrophotometric Determination of Cadmium and Cobalt using Furfuraldehyde Thiosemicarbazone (FFTSC)

The reagent furfuraldehyde thiosemicarbazone (FFTSC) is used to develop a simple, selective and sensitive second order derivative spectrophotometric method for the simultaneous determination of Cd(II) and Co(II). The reagent FFTSC gives yellow color with Cd(II) and Co(II) mixture solution in basic medium. The maximum peaks were observed between 360 nm – 425 nm for both Cd(II) and Co(II) in basic buffer solution of pH 9.0. The molar absorptivity and sandell`s sensitivity of Cd(II) and Co(II)-FFTSC complexes are 3.367x10⁵ L/mol/cm, 3.886x10⁵ L/mol/cm and 0.00297μg/cm2, 0.00257 μg/cm2 respectively. The stability constant of Cd (II) and Co(II)-FFTSC complexes are 3.238x10⁵ and 1.256x10⁵ respectively. The effect of concentrations of Cd(II) and Co(II) ions on amplitude are also studied. The samples of tea leaves, coffee beans, tobacco, rice, mussel and human air were analyzed by the proposed method. The results of the samples are good agreement with the certified reference values ICPAES, RPHPLC and AAS methods.