The radiation-induced fragmentation of squalane, phytane and high-molecular-weight isoprenoid hydrocarbons present in high-boiling petroleum fractions was investigated. The structure of the isoprenoids was determined by 13C NMR spectroscopy, and the identification and quantification of their radiolysis products was performed by gas chromatography. It was found that the vast majority of high-molecular-weight isopranes present in the samples have a regular (i.e., head-to-tail) structure and that their terminal groups have methyl branches at positions 2,6,10,…; 3,7,11,…; 4,8,12,…and 6,10,14,…The ratio of radiation-chemical yields of fragment isoprenoids to that of n-alkanes (G(isop)/G(n-alkane)) correlates well with the isoprenoid content in the sample. Based on the concentration distribution of radiolytic products, an attempt was made to reconstruct the quantitative ratio of isoprenoid end groups in the samples.

A solid phase extraction method for removing polar tritiated contaminants from tritium-containing waste oils has been developed. The composition of the degradation products present in the waste oil was determined. The results indicated that upon exposure to tritium gas, fragment methyl ketones, carboxylic acids, and lactones were the main polar products of the mineral-based oil oxidation. The nonpolar fragmentation products included n-alkanes, monomethylalkanes, and acyclic isoprenoids and were analogous to those formed during \(\gamma\)-irradiation of the oil. Various polar and nonpolar fragmentation products containing an isoprenoid skeleton were found to be formed via an oxidative/radiation scission of long-chain acyclic isoprenoids.

The effect of γ-radiation on the average molecular weight and the molecular-weight distribution of chitosan has been studied. The analysis of samples by gel permeation chromatography/size exclusion chromatography (GPC/SEC) has shown that the amount of high-molecular-weight fractions decreases and the amount of fractions containing low-molecular-weight chitosans (<50 kDa) increases with an increase in the radiation dose. The radiation-chemical yield of degradation is 11.0 particle/100 eV.

144 The studies of processes caused by the action of ionizing radiation on nucleic acids and their main constituents (nitrogen bases, nucleosides, and nucle otides) have been actively performed for almost half a century. The development of analytical techniques such as HPLC–MS/MS and GC–MS made it possi ble to identify the main products formed by the action of radiation (mainly, different hydroxy compounds, which appear as a result of the addition of the OH rad ical or Н2О at the double bond of a nitrogen base) [1– 3]. Cytidine remains the least studied compound in comparison with other pyrimidine nucleosides. This is explained by the lower stability of radiolysis products at the initial stage of the irradiation of cytidine. The mechanism and kinetics of the processes are unclear. In this paper, we consider the kinetics of cytidine deg radation and the buildup of the resulting products, which is important for explaining the mechanisms of the processes of interest.

The γ-radiolysis of solid chitosan was studied. The radiolysis products hydrogen and ammonia were determined by chromatography and spectrophotometry (with Nessler’s reagent), respectively, and the amino groups were determined by potentiometic titration. The radiation-chemical yields were found to be G H 2 = 2.0 ± 0.3; G NH 3 = 5.8 ± 0.4 and G −NH 2 = 2.9 ± 0.8. The molecular mass of chitosan decreases with an increase in the absorbed radiation dose because of its degradation ( G D = 3.6 ± 0.4). A long-term posteffect was observed after irradiation. This is a preliminary report on the study concerning the search for optimal conditions of the synthesis of membranes from modified chitosan for removal of cadmium ions.

Radiolysis of alkylnaphthalene oils was studied. It was shown that the radiation-chemical yield of hydrogen grows linearly (from 0.26 for KR-007A oil to 0.78 for KR-019 oil) with an increase in the average (with allowance for the composition) length of the alkyl chains. A number of liquid alkanes and alkenes (C 5 –C 12 ) along with naphthalene were identified in the radiolysis products. Dimers and polymers make 2–10% depending on the radiation dose. Alkylnaphthalene oils used as additives for synthetic oils of the WM-5 type substantially improve the radiation resistance of these oils.

Radiolysis of chloroalkanes (from chloropropanes to chlorodecane) has been investigated. Hydrogen and hydrogen chloride are the main products of decomposition. Their concentrations linearly grow with the dose in the examined interval up to 150 kGy. The radiation-chemical yield of hydrogen increases from 0.72 for 1-chloropropane to 1.3 for 1-chlorodecane. The opposite trend is observed in the case of HC1: 3.7 for 1-chloropropane and 1.7 for 1-chlorodecane. Products of dechlorination, chlorination (di-and trichloroalkanes) with G 0.8–4.0, isomerization with G up to 90, as well as oligomerization products, have been identified in the liquid products.

Radiolysis of a number of synthetic oils based on polyalphaolefins (WM-5, PAO-2, PAO-4, PAO-6, and PAO-8) has been studied. The radiation-chemical yields of hydrogen, low-and high-molecular-weight products (up to C100) are reported. So, for PAO-4 oil (composition of the oil: 80 % of C30, 13 % of C40, 3 % of C50) the yields of products of radiolysis (1/100 eV) make: \( G_{H_2 } \) = 3.7, G C60 = 0.5.

The radiolysis of vacuum oils was studied. The radiation-chemical yields of hydrogen varied over the range 1.6–3.2 depending on oil brand. A number of liquid radiolysis products were identified. It was found that, in the presence of oxygen, ketones were the main products of the radiation-induced oxidation of oils.

The γ-radiolysis of the α-and β-anomers of D-glucose was studied. The kinetic parameters of mutarotation of irradiated glucoses were determined by polarimetry. The reaction rate constants are independent of the radiation history of samples. The yields of hydrogen from irradiated glucoses were determined by chromatography. The radiation stability of the powdered anomers was the same.

The effects of 60 Co γ-radiation on D-glucose, L-glucose, D-galactose, L-galactose, D-mannose, and L-mannose were studied. The yields of gaseous radiolysis products were determined. The curves of radical buildup and decay in crystalline samples were obtained. Conclusions on the relative radiation stability of these D- and L-monosaccharides to the action of nonpolarized radiation were drawn.

The ESR spectra of gamma-irradiated cellobiose, paper waste, and cellulose extracted from paper waste and waste pulp sludge were analyzed. The kinetics of formation and decay of cellobiose radicals were investigated, and the radiation-chemical yields of the radicals formed in cellulose-containing materials were calculated. The ESR spectra of cellobiose irradiated in the presence of methyl methacrylate (MMA) were obtained. A probable mechanism of MMA grafting onto cellulose-containing matrices is considered.

The kinetics of the radical hydrosylation of herafluoropropylene with methyldichlorosilane using Co-60 gamma-radiation are studied at a temperature of 293-333 K, an absorbed dose of 1.4 Gy/sec, and initial hexafluoropropylene concentrations of 0.08-1.0 mole/liter. The radiochemical yield of the addition products, the addition and transfer constants of the chain, and the activation energy of the process are determined.

Data were presented previously on the composition of products of {gamma}-radiolysis of 1,4-dioxane. The main products are called H{sub 2} and a polymer, the radiation yield of which does not exceed 1.5-3.5 molecules per 100 eV. Gaseous hydrocarbons and CO were identified in small amounts. The authors studied in detail the reaction mixture obtained as a result of radiation-chemical transformations of 1,4-dioxane (reaction time 10-15 h and temperature 130-150{degrees}C) by chromatography-mass spectrometry.

Radiation induced reaction of dichloromethylsilane (Cl2MeSiH) with ketones leads to the formation of products resulting from silyl-radical addition to the oxygen of the ketone carbonyl group. The kinetic dependences derived are described by a radical-chain scheme of the process. A competition kinetics method was used in order to determine relative rate constants of dichloromethylsilyl radical addition to various ketones.