Simultaneous Determinations of Fe²⁺ and Fe³⁺ in Ferrous Sulfate Destined for Pharmaceutical Preparations

ABSTRACT

Only the simultaneous analysis of the amount of Fe²⁻ and the possible presence of Fe³⁺ in ferrous sulfate heptahydrated (FeSO_4. 7 H₂O) can guarantee covered tablets, drops or syrups with insured quality. This work suggests that these analysis are accomplished through spectrophotometric method by use of the 1, 10-phenanthroline as chelate. Thus, at 510 nm the absorption is only due to the complex of the ligand with Fe²⁻ and at 390 nm the absorption is indicative of Fe^2+/3+ coordinated. Pharmaceutical raw matter and covered tablets were analyzed. Techniques of thermogravimetric analysis (TG-DTG) were used for the knowledge of the regions of loss of water of the FeSO₄. 7 H₂O for the relationship to its stoichiometry.

Keywords::

• Ferrous sulfate
• Spectrophotometry
• TG-DTG
• iron-deficiency anaemia