Abstract
A simple, selective, and inexpensive spectrophotometric method is described in the present study for estimation of trace concentrations of Cu2+ in water based on its reaction with chromogenic reagent namely 4-amino-3-mercapto-6-[2-(2-thienyl)vinyl]-1,2,4-triazin-5(4H)-one (AMT). The reaction between copper(II) ions and AMT reagent gives [Cu(L)(NO3)(H2O)(2)]center dot H2O complex, where L represents AMT molecule with NH group. The formed complex exhibits a sharp, and well-defined peak at lambda(max) = 434 nm with a molar absorptivity (epsilon) of 1.90 x 10(4) L mol(-1) cm(-1), and Sandell's factor of 0.003 mu g mL(-2). Absorbance of the [Cu(L)(NO3)(H2O)(2)]center dot H2O follows Beer's law over a 0.7-25 mu g mL(-1) range with a detection limit of 0.011 mu g mL(-1). Validation of the submitted method was established by estimating Cu2+ in certified reference materials and actual sea and tap water samples. The results are compared with data obtained from copper concentration measurements using ICP-OES. The chemical structure of the Cu(II)-AMT complex was fully characterized by FT-IR, SEM, EDX, TGA, and ESR techniques.