Radiation spectra of electric discharge in cytosine vapors


Background. Various actions on bioinformational DNA and RNA molecules can cause uncontrollable changes in a genotype of living organisms. One such external factor is high-energy ionizing radiation, which generates intracellular powerful flows of low-energy secondary electrons with energies from 0.1 to tens of electronvolts. The molecules of nitrogen bases, i.e., pyrimidine derivatives (cytosine, thymine, and uracil) and purine derivatives (adenine and guanine) are the important components of the architecture of nucleic acids. Secondary electrons can later initiate dissociative capture, excitation, and ionization of base molecules, which, in their turn, trigger a chain of destructive changes in DNA and RNA macromolecules. 
Materials and methods. The experimental study of the luminescence vapors cytosine under the conditions of electrical discharge. The technique of the experiment is to obtain and study optical spectra of the luminescence of electric discharge which light up the tube, filled with vapors of cytosine molecules. Experimental conditions were as follows: pressure of molecules vapors ~ 10-2 Pa, the current intensity of discharge Ір = 10 mA, voltage in the discharge gap – 540V. Class of discharge − smoldering. 
Results. The resulting luminescence spectra of discharge in the wavelength range from 200 up to 500 nm were obtained. Spectral lines and bands with maxima at wavelengths of 281, 295, 311 − 316, 328, 336, 348, 352 − 357, 375, 380 − 387, 390, 398, 413 − 421, 427, 452 and 485 nm were detected in analyzing of these spectra. For some molecular bands was shown their most likely identification. 
Conclusion. Experiments on excitation of molecules cytosine in electrical discharge were executed. The luminescence spectrum of cytosine in electrical discharge is forming by the processes of dissociative excitation of molecules, dissociative excitation with ionization, excitation of electronic levels of the original molecule. The experimental approach used in this study made it possible to obtain new data on the electron impact excitation of cytosine molecules


Keywords: cytosine, glow dischange, excitation, spectrum, spectral bands