Nazimunnisa, S. et al. 2023. First-Order Derivative Spectrophotometry Method with Triapine as Chelating Agent for Simultaneous Determination of Barium(II) and Lead(II). Asian Journal of Chemistry. 35, 5 (Apr. 2023), 1231–1236. DOI:https://doi.org/10.14233/ajchem.2023.27793.