Determination of Iron in Phytoplankton Cultures by Radiochemical Analysis with ⁵⁵Fe

Abstract

Radiochemical analysis using iron tracer, ⁵⁵Fe, with liquid scintillation counting is a simple, sensitive and reliable method for determination of low-level iron, and is useful for iron speciation in laboratory culture experiments of marine phytoplankton. In this paper, we studied interferences from the components of the culture media, established the analytical conditions, and measured iron distribution including dissolved, particle, intra- and extracellular iron in marine phytoplankton cultures. The results from iron uptake experiments showed that bioavailability of iron to phytoplankton was related to the iron speciation in the presence of the chelating ligands.