Taher, M.W., Guzar, S.H. and Hanoon, H.D. 2022. Spectrophotometric determination of Co (II) in analytical sample using anew chromogenic reagent (PTMH). International journal of health sciences. 6, S8 (Jun. 2022), 1082–1095. DOI:https://doi.org/10.53730/ijhs.v6nS8.9788.