Unusual temperature dependencies of Mössbauer parameters of the nanosized iron cores in ferritin and its pharmaceutical analogues

Human liver ferritin and its pharmaceutical analogues, namely, Maltofer®, Ferrum Lek and Ferrifol®, were examined using temperature variable Mössbauer spectroscopy. The best fits of measured spectra at 295–90 K were performed using 5 quadrupole doublets with equal line widths. Obtained components were associated with various layers and/or regions of nanosized iron cores with different size and packing arrangement. Unusual temperature dependencies of line widths, normalized total and relative areas, isomer shifts and quadrupole splittings were observed and related to the low temperature structural rearrangements in different layers/regions of the iron cores in ferritin and its analogues.