Simultaneous Second Order Derivative Spectrophotometric Determination of Mercury and Cobalt Using Furfuraldehyde Thiosemicarbazone (FFTSC)

A simple, selective and sensitive second order derivative spectrophotometric method is developed using FFTSC (furfuraldehyde thiosemicarbazone) for the simultaneous determination of Hg(II) and Co(II). The reagent FFTSC gives yellow colour with Hg(II) and Co(II) mixture solution in basic medium. The maximum peaks were observed in between 360nm - 420nm for both Hg(II) and Co(II) in basic buffer solution of pH 8.5. The molar absorptivity and sandell`s sensitivity of Hg(II) and Co(II)-FFTSC complexes are 2.2x10⁴ L/mol/cm, 4.3x10³ L/mol/cm and 0.000454 μg/cm², 0.00232 μg/cm² respectively. The stability constant of Hg (II) and Co(II)-FFTSC complexes are 3.495x10⁶ and 5.176x10⁴ respectively. The effect of concentrations of Hg(II) and Co(II) ions on amplitude are also studied. The samples of tap water, distilled water, human tissues and blood samples were analyzed by the proposed method. The results of the samples are good agreement with the certified reference values APARI, CVAAT and AAS methods.