Downscaling conventional methods for the spectrophotometric study of metal ions complexation

One of the major challenges in a chemistry laboratory is the continuous search for a more sustainable practice, following Green Chemistry guidelines. The present work was devoted to the development of a high throughput and miniaturized strategy for chemistry conventional protocols for the study of complex formation of metallic compounds. In this scenario, the spectrophotometric calibration curve method and the Job’s method of continuous variation were adapted to the microplate format. This work involved several metal ions (Co(II), Cu (II), Cd(II), Fe(III), Mn(II), Ni(II), Pb(II) and Zn(II)) and two different complexing agents, 2-Carboxy-2′-hydroxy- 5′-sulfoformazyl-benzene (Zincon) and 4-(2-Pyridylazo)resorcinol (PAR). Microplate assays demonstrated to be useful tools for the investigation of the equilibrium process of metal ion complexes. Additionally, these methods involved lower volume of reagents and the analysis throughput was augmented when compared with conventional strategies.