A Friendly Complexing Agent for Spectrophotometric Determination of Total Iron

Iron, one of the most common metals in the environment, plays a fundamental role in many biological as well as biogeochemical processes, which determine its availability in different oxidation states. Its relevance in environmental and industrial chemistry, human physiology, and many other fields has made it necessary to develop and optimize analysis techniques for accurate determination. Spectrophotometric methods are the most frequently applied in the analytical determination of iron in real samples. Taking advantage of the fact that desferrioxamine B, a trihydroxamic acid used since the 1970s in chelation therapy for iron overload treatment, forms a single stable 1:1 complex with iron in whichever oxidation state it can be found, a smart spectrophotometric method for the analytical determination of iron concentration was developed. In particular, the full compliance with the Lambert-Beer law, the range of iron concentration, the influence of pH, and the interference of other metal ions have been taken into account. The proposed method was validated in terms of LoD, LoQ, linearity, precision, and trueness, and has been applied for total iron determination in natural water certified material and in biological reference materials such as control human urine and control serum.     

Interference by Desferrioxamine of Spin Trapping Oxy-Radicals For ESR Analysis

Abstract

The iron chelator desferrioxamine (DEF), commonly used to assess the involvement of iron in oxy-radical production, was examined with respect to its effect on spin trapping oxy-radicals generated independently of iron. OH. was generated by photolysis of H₂O₂- was generated by photolysis of Cds dispersions and by the hypoxanthine-xanthine oxidase system.In the presence of DEF, the amount of the radicals detected by spin trapping techniques of ESR with 5,5-dimethyl-1-pyrroline-1-oxide was greatly diminished. These results confirmed that DEF is an oxy-radical scavenger and, in addition, indicated that it should not be used to assess the involvement of iron in oxy-radical generation during spin trapping with nitrones for ESR analysis.

An additional finding was that a new radical, as yet uncharacterized, was generated by UV irraditional of DEF.