[Problems in the monitoring of bromine-containing substances in the drinking water].

The water concentrations of bromide ions at the level of 0.2 mg/dm3 or higher, which are sufficient for redox reaction of humin compounds under the action of potent oxidizing agents present a potential hazard in the hygienic terms of formation of transformation products, which also agrees with the hygienic standards. The concentration of bromide ions below 0.1 mg/dm3 can be considered to be relatively safe in the terms of production of organobromine compounds.

[Transformation of surfactants in different ways of water disinfection].

Evaluation of the efficacy ofoxidants on the destruction of bisquartemary ammonium salts (BAS) in water demonstrated that the highest destruction effectiveness was achieved upon exposure to ozone (87%), potassium permanganate (68.2%), ultraviolet radiation (37.8%), by chlorination with gas chlorine (35.4%), lime chloride (24.1%), the least destruction was achieved by chlorination with sodium hypochlorite (21.9%). There was a more than 2-fold increase in the level of low-molecular impurities upon chlorine exposure of the water containing BAS as a result of transformation processes. In ozone treatment of BAS, unlike its chlorination, there was as high as 2-fold decrease in the concentration of C6-C9 alcohols present in their composition, giving rise to C6-C9 aldehydes (0.5%) and C6-C9 organic acids (as high as 3% of the mass content).

[Assessment of real risk of urban chemical exposure to the population's health].

Improving the chemoanalytical quality control of the urban environment requires transition from the assessment considering only certain things determined by target analyses to the comprehensive assessment based on monitoring with the identification of the maximally complete spectra of substances contained in the environmental objects and coming from the sources of pollution, by using the appropriate algorithm; identification, quantifying a spectrum of pollutants as completely as possible; selection of the leading indices, by evaluating the detected composition of pollutions from the degree of their hygienic significance, by taking into account a set of criteria (detection rate, concentrations, group affiliation, specificity for a nearby source of pollution in the check of drinking water, a capacity for transformation, possible formation of more toxic transformation products); and monitoring through target tests by the chosen leading indices.

[Hygienic evaluation of genotoxic effects during artificial air ionization].

The study examined the potential genotoxic activity and the impact of artificial air ionization on lifespan. Experiments on Drosophila melanogaster demonstrated that exposure of the lung to negative (5 x 10(4), 5 x 10(5), and 10(6) ion/cm3) and slight positive (5 x 10(4), 5 x 10(5), and 10(6) ion/cm3) airoions generated on the electrodes at direct-current voltage failed to increase the frequency of dominant lethal mutations in the gametes and to affect the life-span of male flies. Exposure of the flies to deionized air increased the rate of early embryonic lethal mutations.

[Metabolism of S-methylmethionine (vitamin U) in animals]. / Metabolizm S-metilmetionina (vitamina U) u zhivotnykh.

Metabolism of S-methylmethionine (vitamin U) has been studied in rats. Biotransformation of this compound actively proceeds in the liver, kidneys, and digestive tract. Metabolism of S-methylmethionine in the liver and kidneys was found to proceed both via methylation of homocysteine with the formation of methionine and via enzymatic hydrolysis to dimethylsulfide and homoserine. In the digestive tract, only the activity of S-methylmethionine-sulphonium hydrolase was found. The physiological role of the metabolic routes under study is discussed.

[S-methylmethioninesulfonium hydrolase activity in plant and animal tissues]. / Izuchenie aktivnosti S-metilmetioninsul'fonii-gidrolazy v rastitel'nykh i zhivotnykh tkaniakh.

A gas-chromatographic technique is proposed for determining the activity of S-methylmethionine-sulphonium-salt hydrolase in homogenates of plant and animal tissues. The enzyme was found in flowers, leaves and fruits of different plants. The enzymatic hydrolysis of S-methylmethionine was found for the first time in different organs of animals, liver and kidneys possessing the highest enzyme activity.

[Nonenzymatic formation of 4,5-dimethyl-3-hydroxy-2(5H)-furanone in foodstuffs]. / Nefermentivnoe obrazovanie 4,5-dimetil-3-oksi-2(5H)-furanona v pishchevykh produktakh.

The mechanism of formation of 4,5-dimethyl-3-hydroxy-2/5H/-furanone in some food-stuffs was investigated. The compound was found to result from condensation of acetaldehyde under oxidative conditions. The intermediate product of the condensation is 2-oxobutanoic acid.

[S-methyl methionine (vitamin U) pharmacokinetics in rat and man]. / Farmakokinetika S-metilmetionina (vitamina U) u krys i cheloveka.

S-methyl methionine was shown to be rapidly absorbed, accumulated in the liver and kidneys and actively assimilated by the organisms of rats and man. Some constants of pharmacokinetics of different optical forms of S-methyl methionine were determined. The predominant use of L-form was found. The concurrent administration of D- and L-forms stimulates processes of D-form assimilation.

[Gas chromatographic determination of S-methylmethionine (vitamin U) in plants]. / Gazokhromatograficheskoe opredelenie S-metilmetionina (vitamin U) v rasteniiakh

A quantitative gas-chromatographic method to assay S-methyl methionine (vitamin U) in plants has been developed. The method is based on the disintegration of S-methyl methionine in the alkaline medium to form equimolecular quantities of dimethyl sulphide and homoserine. Dimethyl sulphide is distilled in the flow of an inert gas (nitrogen) and trapped in the toluene trap cooled to--78 degrees. The toluene solution containing dimethyl sulphide and carbon tetrachloride as an inner reference is analyzed in a gas chromatograph. Optimal conditions for the reaction to form 91.1% dimethyl sulphide from S-methyl methionine sulphonium chloirde at concentrations ranging from 0.1--5.0 mg% have been established. The standard error of measurements is +/- 1.5%.