The analysis of active products of spark discharge plasma radiation determining biological effects in tissues

Abstract

The aim of the investigation is to analyze active products of spark discharge plasma radiation determining biological effects in tissues, estimate the radiation intensity, identify the resulting products and determine their concentrations. Materials and Methods. The radiation intensity of discharge was estimated by means of detecting 1.5% solution of potassium iodine. The possibility of OH• and HO2• formation was analyzed by oxalic acid and mohr's salt solutions. Hydrogen peroxide concentration was assessed by titanium ions test (λ=410 n{cyrillic}m{cyrillic}). And NO3 - ion formation was studied by means of ion selective electrodes. There was carried out chemical analytical and spectrophotometric analysis of products absorption over the range of λ=200-400 nm to identify the products forming and accumulating in liquid phase of discharge. The active products forming in gas phase of discharge were analyzed by Fourier infrared absorption spectra. pH was measured by device "Expert 001". All the solutions were treated in discharge optimal conditions: the capacity of pulse capacitor C=3.3 nanofarad, ballast resistance R=10 M{cyrillic}Ohm, power supply voltage UPS=11 kV, pulse recurrence frequency - 10 Hz. Results. Spark discharge plasma radiation initiates UV photon beam (2.5±0.3)·1015 (cm2·s)-1, with energy density (2.0±0.3)·10-3 J(cm2·s)-1, maximum radiation spectrum - 220 nm. Under discharge pH in water samples decreases, oxidizers and deoxidizers accumulate. There have been identified radicals HO2•, initial yield - (1.2±0.3)·10-6 mol(l·s)-1. Initial yield of acid residues ([H+] increase) - (5.8±1.6)·10-7 mol/(l·s)-1, oxidizers (3.3±1.0)·10-6 mol-equiv./(l·s)-1, deoxidizers (4.2±1.0)·10-7 mol-equiv./(l·s)-1. The formation of nitro compounds containing CN, NH groups and organic compounds containing CH, CC groups has been proved. Nitrogen oxides and organic compounds make the main contribution to pH decrease.