Method of increase of signal/noise ratio in EPR spectroscopy
Keywords:
EPR spectroscopy, sensitivity of spectroscopy instruments, signal extraction, signal-tonoise ratio, spectrum accumulation, Hurst methodAbstract
The purpose of the study was to develop a technique for increasing the sensitivity of spectroscopy based on the phenomenon of electron paramagnetic resonance (EPR) for the analysis of objects for which EPR studies have limitations because of the low concentration of paramagnetic centers in them. Studies of such objects are difficult because of the low signal-to-noise ratio and, as a consequence, the low sensitivity of scientific equipment. A method for increasing the signal-to-noise ratio in EPR spectroscopy is presented. The method can be used to increase the sensitivity of spectroscopic instruments operating in a continuous mode. The method is based on the fact that a useful signal is extracted from noise by combining two actions: the accumulation of deviations from the mean value of the spectrum along the spectrum (horizontal accumulation) and averaging the spectrum over time (vertical accumulation). To analyze and quantify the value of the accumulated deviation of the values of the analyzed sequence, a modified Hurst method was used, which makes it possible to search for and analyze correlations in spectra of various types. The method achieves the same signal-to-noise ratio as the standard method of
time averaging (vertical accumulation of the spectrum) used in magnetic resonance spectroscopy, for
time period about two orders less.
References
2 V. Nadolinny, A. Komarovskikh and Y. Palyanov, Crystals 7(8), 237 (2017). doi: 10.3390/cryst7080237
3 J. Niklas and O.G. Poluektov, Adv. En. Materials 7(10SI), 1602226 (2017). doi: 10.1002/aenm.201602226
4 M.M. Roessler and E. Salvadori, Chem. Soc. Rev. 47(8), 2534-2553 (2018).
5 J. Kemsley, Chem. Eng. News 95(25), 8-8 (2017).
6 P. Olczyk, K. Komosinska-Vassev, P. Ramos, L. Mencner, K. Olczyk, and B. Pilawa Molecules 22(1), 128 (2017). doi:10.3390/molecules22010128.
7 Stefaniuk, D. Wróbel, A. Skrȩt, J. Skrȩt-Magierło, T. Góra, and P. Szczerba, Current Topics in Biophysics. 37, 23-28 (2014).
8 C.L. Hawkins and M.J. Davies, Biochimica et Biophysica Acta-General Subject 1849 (2SI), 708-721 (2014). doi:10.1016/j.bbagen.2013.03.034.
9 H. El Mkami and D.G. Norman, Methods in Enzymology, 564, 125-152 (2015). doi: 10.1016/bs.mie.2015.05.027.
10 P.L. Guzzo, B.G. Nobrega and B. Obryk, J. Lumin. 198, 284-288 (2018). doi: 10.1016/j.jlumin.2018.02.048.
11 L.J. Berliner, Biomedical Spectroscopy and Imaging 5(1), 5-26 (2016). doi: 10.3233/BSI-150128.
12 Marciniak and B. Ciesielski, App. Spec. Rev. 51(1), 73-92 (2016). doi: 10.1080/05704928.2015.1101699.
13 N.A. Chumakova, T.A. Ivanova and E.N. Golubeva, Appl. Mag. Res. 49(5), 511-522 (2018).
14 S.I. Andronenko and S.K. Misra, App. Mag. Res. 46(6), 693-707 (2015). doi: 10.1007/s00723-015-0686-z.
15 J. Kausteklis, P. Cevc, D. Arcon, L. Nasi, D. Pontiroli, M. Mazzani and M. Ricco, Phys. Rev. B. 84(12), 125406 (2011).
16 Pivtsov, M. Wessig, V. Klovak, S. Polarz and M. Drescher, J. Phys. Chem. C 122(10), 5376-5384 (2018). doi:10.1021/acs.jpcc.7b10758.
17 Savoyant, H. Alnoor, S. Bertaina, O. Nur and M. Willander, Nanotechnology 28(3), 035705, (2017). doi: 10.1088/1361-6528/28/3/035705.
18 N. Guskos et al. Rev. Adv. Mat. Sci. 52 (1-2), 14-17 (2017).
19 V. Nosenko et al. Nanoscale Research Lett. 11, 517 (2016). doi: 10.1186/s11671-016-1739-4
20 S.A. Dzyuba, Osnovy magnitnogo rezonansa (Novosibirsk, NGU, 2010). (in Russ).
21 M.P. Klein and G.W. Barton, RSI 7, 754-759 (1963).
22 R.R. Ernst, RSI 36, N12, 1689-1695 (1965).
23 J. Feder, Fractals (Plenum Press, New York, 1988).
24 Ch.Pul, Tekhnika EPR-spektroskopii (Mir, 1972), (in Russ).
25 Brun R., Lienard D. CERN computer center program library long write-up.
