Extraction of iron from plant leaves by Fe (II) chelators

Abstract

In the working conditions used for the extraction of iron with 1,10‐phenanthroline (o‐phe) or 2–2’ Bipyridyl (Bipy) from plant material, in vitro photoreduction of ferric ions occurs. Nevertheless, iron in plant extracts was found to be independent of the illumination conditions where the sample was maintained during the extraction. Ferric iron added to a plant extract was completely reduced in the darkness. These data seem to indicate that if extraction of ferric iron occurred, it would be reduced and measured as ferrous iron. Thus, the form of iron being extracted may be better called “active”; or “labile”; instead of ferrous iron.

The use of o‐phe for the study of iron deficiency may give misleading conclusions, because of the simultaneous extraction of chlorophyll degradation products. The use of either Bipy or a purification step involving C₁₈ cartridges is suggested.

A high correlation between “active”; iron and chlorophyll in peach trees was found.

Key words:

• Iron chlorosis
• Fe (II) chelators
• 2–2’ Bipyridyl
• 1,10‐phenanthroline
• active iron