Application of Moessbauer spectrometry in the study of biological materials

This contribution is focused on the analysis of iron properties in samples of biological tissues from the point of view of demonstration of their magnetic properties and structural positions. ⁵⁷Fe Moessbauer spectrometry in transmission mode was applied as a principal investigation tool. Absorption spectra were recorded directly from lyophilized tissues of human brain. Moessbauer measurements were performed at room temperature (∼300 K) and at the temperature of 4.2 K using liquid helium bath cryostat. Each spectrum obtained at room temperature exhibit doublet-like features, which indicated presence of very small non-magnetically ordered or superparamagnetic particles. Low-temperature Moessbauer spectra are superpositions of sextets and one doublet. Spectral parameters of the sextet-like components are similar to those for hematite, ferrihydrite or possibly magnetite. (authors)