التقدير الطيفي لأيون المنجنيز الثنائي باستخدام معقداته مع الموريكسيد في خليط من الماء و 2بروبانول

This paper deals with the use of murexide indicator as a ligand for spectral estimation
of Mn (II). The effect of using different ratios of (2-propanol: water) mixtures on the absorption spectrum of murexide as well as its complexes with the studied metal ion was investigated. The effect of some factors affecting the stability of these complexes, such as time and pH, were studied at different solvent ratios: (2: 8), (4: 6), and (3:7) of 2-propanol and water, respectively. The stoichiometry, stability constant and
molar absorptivity were estimated using the method of continuous variations of the murexide complexes with Mn (II) at the ratio (3: 7) and the results were as follows: 1:2, 1X1013, 7322 L.mol-1.cm-1, respectively, while these complexes were not stable enough to be studied in the other ratios. The spectral method for estimating this ion was evaluated at the ratio (3:7), by estimating the sensitivity, detection limits, quantification
limits, and the linear range of the Pierre - Lambert law, where the obtained results were: 0.160 ppm-1, 0.0290 ppm, 0.0966 ppm, 0.2-3.5 ppm, respectively. The effect of increasing the concentration of ions on the reliability of the proposed spectroscopic method was also studied, and it was found that the degree of reliability decreases at high concentrations of these ions.