Inorganic Nitrate Determination Employing Co(II) Complex Potentiometry

The research presented here describes the development of membranes made of polymeric materials with unique cobalt(II) complexes to identify nitrate anions in water. The authors of the study precisely coordinated cobalt(II) ions with a neutral tetradentate ligand known as N,N-Ethylene bis(Salicylideneaminato) to develop an efficient anion-binding carrier with nitrate sensitivity. Good nitrate specificity was accomplished by incorporating these Co(II) complexes onto membranes alongside the plasticizer dibutyl phthalate (DBP). The improved Co(II)-based sensors achieved near-Nernstian response slopes throughout a large linear detecting span of 5.0×10−6 to 1.0×10−1 M nitrate, retained functionality from pH 3 to 12, and responded quickly in about 15 seconds. Potentiometric sensitivity factor analyses revealed that the fabricated Co(II) sensor membrane had a higher sensitivity for nitrate compared to more conventional ions. In general, this study highlights the potential of customized Co(II) complexes incorporated into polymeric membranes to be selective and efficient potentiometric sensors for detecting nitrate anions in water bodies. It serves as a foundation for developing enhanced nitrate detection systems for use in important environmental as well as health monitoring processes.