Determination of desferrioxamine-available iron in biological tissues by high-pressure liquid chromatography.

Intracellular iron loosely bound to proteins such as ferritin or in the form of low molecular weight chelates is available to catalyze adverse reactions such as the formation of reactive free radicals. A method to measure this small but important iron pool by utilizing the highly specific iron-chelator desferrioxamine is described. Following incubation of tissue fractions with desferrioxamine, the parent compound and its iron-bound form, ferrioxamine, are extracted using solid-phase cartridges and quantitated by reversed-phase HPLC using uv detection. Calculation of the ferrioxamine:desferrioxamine ratio and comparison with a standard curve constructed using a series of known iron concentrations allow the determination of micromolar amounts of desferrioxamine-available iron in biological samples.