[en] CH₃CHOH, H^·, e_solv^- are the main active radicals in the ethanol system irradiated by γ-ray without the presence of oxygen. In this study, GL ethanolic solution saturated with nitrogen was γ-irradiated, the radiolytic products were isolated by HPLC and the molecular structure was determined with UV, IR, MS spectra and elementary analysis methods. In this system GL reacts with H^· and CH₃CHOH radicals. CH₃CHOH adds to the C-C double bond of GL, then the formed radicals disproportionate to the final products RP1 (olean 29-oic acid,3-hydroxy-11-oxo-12-ethoxyl-13-hydro-,(3β, 20β)-) and RP3. H^· reacts with GL in the similar way. The rate constant of H^· reacting with GL was obtained as k_GL+H^·=2.0x10¹⁰ dm³ mol^-1 s^-1. The rate constant of CH₃CHOH reacting with GL was calculated as result of (1.2±0.1)x10⁴ dm³ mol^-1 s^-1 by using steady state method and by using the numerical quadrature method with computer. G(-GL), G(H₂ ), G(2,3-butanediol), G(CH₃CHO) and G values of the radiolytic products of ethanolic solution with different GL concentration were measured. A material balance was obtained. Results show that the active site of a GL molecule is the C-C double bond. The radiation chemistry technique can be used to modify the structure of glycyrrhetinic acid

[en] The mechanism and kinetics of glycyrrhizic acid monoamonium (GAM) reacting with hydroxyl radical generated by γ-ray irradiated N₂O-saturated aqueous solutions were studied. The radiolytic products were separated with HPLC and the molecular structures were determined by UV, IR, MS and elementary analysis methods. The major product was formed by the attack of hydroxyl radical to the C-C double bond of GAM. The others resulted from the release of one and two glucuronic acid molecules in GAM respectively. The rate constant of GAM reacting with the hydroxyl radical was measured using a competition method by pulse radiolysis technique to be of 3.0x10⁹ dm³ mol^-1 s^-1. The transient species generated by pulse radiolysis of GAM aqueous solution saturated with N₂O at pH 10 exhibited an absorption maximum at about 325 nm with extinction coefficient 260 dm³ mol^-1 cm^-1. The rate constant of second-order decay of transient species was 5.8 x 10⁸ dm³ mol^-1 s^-1. The transient species was formed by the attack of hydroxyl radical to the C-C double bond of GAM. The G values of GAM and its radiolytic products of 4.0x10^-4 mol dm^-3 aqueous solution saturated with N₂O at absorbed dose of 500 Gy are: G(-GAM) = 2.4, G(RP1) 2.2, G(RP2) = 0.3, G(RP3) = 0.1

[en] OH-radical-induced dechlorination of pentachlorophenol (PCP) has been studies pulse and γ-radiolytically. OH radicals react with PCP by both electron transfer (53%) and addition followed by very rapid HCl-elimination to form phenoxyl radicals. The phenoxyl radicals decay to form products (e.g. chloranil) that unstable in alkaline aqueous solution and release some more Cl^-, therefore G(Cl^-) is high. Primary HPLC-MS analysis reveals that some quinones among the final products, whose toxicity remains unclear. Ozone can also oxidize PCP very rapidly, and this oxidation may destroy the benzene ring of PCP

[en] Radiolysis of rutin was performed in aerated ethanolic solution. Two major radiolytic products (RP1, RP2) were isolated by HPLC, and their possible structures were deduced from their UV, IR and MS spectra, and elementary analysis as well. The G-values of RP1 and RP2 increase with increasing rutin concentration, and in all cases both of them equal the G-value of rutin consumption. The addition of rutin leads to the decrease of G(H₂O₂) but has little effect on G(CH₃CHO). Therefore the formation of RP1 and RP2 was proposed to be from further addition of HO%s· ₂ to the phenolic radical (generated from H-abstraction by HO%s· ₂) followed by fragmentation

[en] Short communications only

[en] Short communication. 2 refs, 2 tabs

[en] The separation of radiolysis products of deaerated baicalin ethanolic solution by reverse HPLC was studied, especially, the functions of acid in eluent and the influence of solvent strength on separation were discussed. Twelve radiolysis products were successfully separated on the enhanced ODS column with eluent 37%CH₃OH + 63%(0.01CF₃COOH-H₂O)

[en] The decomposition of PCP in water induced by γ-irradiation has been studied at low PCP concentration under various conditions. PCP is consumed linearly with increasing absorbed doses. PCP could be decomposed almost completely by γ-irradiation at relatively high doses. Chloride ions are increased simultaneously with the consumption of PCP. The amount of chloride increases also linearly with the increasing absorbed dose. At relatively high absorbed dose, almost all chloride atoms in PCP are eliminated. Chemical oxygen demand (COD) has been measured after irradiation. Ozone is a powerful oxidizing agent for PCP. After saturation of 1.09x10^-4 mol.dm^-3 PCP aqueous solution with ozone, PCP concentration drops to 1.6x10^-5 mol.dm^-3. The combination of ozonation-ionizing radiation treatment is very effective, which greatly decreased the dose needed. pH and chemical oxygen demand also have been measured after ozonation and irradiation

[en] Via γ-irradiation of baicalin in ethanol, hydroxylethyl groups were introduced into B and C rings of baicalin. Eight hydroxylethylation products were separated by reverse HPLC and their molecular structures were postulated through their UV, IR, MS and fluorescence spectra. The primary binding constants of baicalin and its hydroxylethylation products in HSA were obtained by the fluorescence method. (author)

[en] The aim of this work was to investigate γ radiation treatment of pentachlorophenol (PCP), 2,4- dichlorophenol (DCP) and o-chlorophenol (o-CP) in water. The dechlorination of PCP, DCP and o-CP has been studied using γ radiation as well as ozonization. G(CI-) is always much higher than the corresponding G(-PCP),this means that some primary radiolytic products are unstable during post irradiation. PCP is much easier to be decomposed under irradiation than that of simple chlorophenol. Some stable radiolytic intermediates were be detected. Primary analysis reveals some quinones among the final products with toxicity that remains unclear. In the pulse radiolytic experiment, it was determined that about 53% of radicals undergo electrotransfer and others undergo addition when OH radicals react with PCP. The values of COD(Mn) after irradiating PCP in dosage were determined. It is recommended to bubble ozone simultaneously when radiation (or electron beam) treat CPs contaminating water. (author)