EUCMOS 2008

     Mössbauer spectroscopy is a useful technique for biomedical research [1–4]. Majority of previous Mössbauer spectra of various samples including biological subjects were measured in 512 channels or less. However, biomedical applications of Mössbauer spectroscopy need the high quality measurement using high stable and precise spectrometer with higher velocity resolution. This requirement is determined in part by importance of Mössbauer study of small variations of hyperfine parameters of iron-containing biomolecules in normal and pathological cases (see [5]), by necessity to decrease experimental error in determination of Mössbauer hyperfine parameters and to reach more reliable fit of complicated Mössbauer spectra. In the present work we consider preliminary results of some biomedical applications of Mössbauer spectroscopy with high velocity resolution.
     Study of iron-containing proteins, ferritin and its pharmaceutically important model compound Imferon, chicken liver and spleen tissues and iron-containing pharmaceutical products was made using high precision, sensitive and stable spectrometer SM-2201 with the saw-tooth velocity reference signal. Mössbauer spectra were measured in transmission geometry with moving absorber and registration in 4096 channels with further presentation in 1024 and 2048 channels by consequent summation of four or two neighboring channels, respectively, and in 4096 channels. Improvement of velocity resolution, for instance, revealed clear differences of hyperfine parameters for Imferon and ferritin (Fig. 1). Different fit of ferritin Mössbauer spectra measured with various velocity resolutions using superposition of four quadrupole doublets was shown (Fig. 2). Obtained results demonstrate that increase of velocity resolution in Mössbauer spectroscopy raises spectra quality and possibilities of this technique in biomedical research.

Fig. 1: Differences of the hyperfine parameters for one quadrupole doublet fit of Mössbauer spectra of Imferon () and ferritin (◊) presented in 2048 channels (experimental error is ± 0.0024 mm/s) in comparison with those presented in 512 channels (■ and respectively; experimental error is ± 0.0096 mm/s).

Fig. 2: Comparison of four doublets fit for Mössbauer spectra of ferritin measured in 512 and 4096 channels with the same statistics. T=295 K.