Investigators prepared different sizes of iron particles samples. Following that, an in-vitro ionization reaction was involved by placing equal amounts of iron suspensions into 0.1M hydrochloric acid solution (stomach environmentsimulation). The concentration of iron ions (Fe2+) in the samples was determined versus time. The concentration of iron ions in the samples was determined using the spectrophotometric method by measuring the absorbance at a wavelength of 511 nm in relation to a colored indicator – phenanthroline – according to the literature data this value selectively corresponds to maximum absorbance for iron (II) – phenanthroline complex.
In this study, the elemental iron powder was used with different particle size medians of 5.2 μM (Reference A), 9.5 μM (Reference B), and 8.5 μM (Reolin). The iron particle sizes characteristics are shown below.