Presence Of Sulfur Dioxide Research Articles

Germination and Metabolism of Pinus radiata Pollen in the Presence of Sulfur Dioxide

Summary Pinus radiata pollen grains produced in the geothermal regions of New Zealand are likely to be exposed to atmospheric SO 2 . Tests have been made to assess whether SO 2 adversely affects the germination of the pollen and whether exposure to the gas alters the early metabolism. Inhibition of germination was confirmed microscopically. The pollen grains were allowed to germinate in tritiated water after they had been exposed to a range (0.1–10.0 ppm) of sulfur dioxide concentrations and the 3 H-labelled metabolites were identified by chromatographic and autoradiographic techniques. The percentage activity incorporated into aspartic, γ-amino-butyric-, citric-, glutamic-, and malic-acids, alanine and glutamine generally decreased as the SO 2 concentration increased.

ChemInform Abstract: ESR Study of the Radicals Formed by UV Irradiation of TiO2 in the Presence of Sulfur Dioxide and Oxygen.

AbstractThe SO2‐ radical can be formed on the surface of TiO2 by heating the sample in ,the presence of SO2 at 573 K and quenching at 77 K or by UV irradiation of TiO2 at 77 K in the presence of SO2.

Electron spin resonance study of the radicals formed by ultraviolet irradiation of TiO2 in the presence of sulphur dioxide and oxygen

A sulphoperoxy radical ([graphic omitted]) has been formed on TiO2 and studied by electron spin resonance spectroscopy using 17O-enriched oxygen. It has the following magnetic parameters: g1= 2.040, g2= 2.008 and g3= 2.002; A1≈A2≈ 0-G, A3(OI)= 106 G and A3(OII)= 42 G. This species can be obtained by the reaction at 77 K of SO–2 radicals and oxygen. The SO–2 is produced on the surface of TiO2 by heating the sample in the presence of SO2 at 573 K and quenching at 77 K. A similar SO–2 species can be formed by u.v. irradiation of TiO2 at 77 K in presence of SO2. A higher concentration of the O2SOO– radical is obtained when the irradiation is performed in presence of both oxygen and sulphur dioxide. The O2SOO– radical is unstable at 298 K, giving some diamagnetic products via intermediate O–2 species (g1= 2.020, g2= 2.009 and g3= 2.002; A3= 78 G).

Quantitative determination of thiourea in aqueous solution in the presence of sulphur dioxide by Raman spectroscopy

A method has been developed for the quantitative determination of thiourea in aqueous solutions acidified with sulphuric acid in the presence of sulphur dioxide. The method uses laser Raman spectroscopy and is valid in the presence of high concentrations of sulphur dioxide and inorganic salts. This is particularly important with respect to the use of such solutions for the leaching of gold from ores and concentrates. The method is simple, rapid and accurate to within ±1.2% and has been applied to the study of solutions used in leaching experiments.

Use of a silver-gelatin complex for the microdetermination of hydrogen sulphide in the atmosphere

Gelatin forms a weak complex with silver(I) in alkaline medium, which was found to be suitable for the determination of 0.6–35 p.p.b. of hydrogen sulphide by spectrophotometry and 0.3–30 p.p.b. of hydrogen sulphide using a column packed with silica gel impregnated with the complex. The method was applied successfully to the determination of hydrogen sulphide under different environmental conditions. The molar absorptivity of the solution is 2.06 × 104 l mol–1 cm–1 for the spectrophotometric procedure, which has a relative standard deviation of 1.2%, a confidence limit (for 20 determinations) of 11.976 ± 0.023% and a Sandell sensitivity of 1.65 × 10–3µg cm–2. The relative standard deviation and confidence limit for the column method (20 determinations) were 0.12% and 4.99 ± 0.003, respectively, even in the presence of sulphur dioxide and carbon monoxide.

ChemInform Abstract: DIAZO REACTIONS WITH UNSATURATED COMPOUNDS. III. ANIONOARYLSULFONYLATION OF SOME DIENE HYDROCARBONS

AbstractDiene (I) reagieren mit Diazoniumsalzen (All) und Schwefeldioxid in Gegenwart von Kupfersalzen unter 1,4‐Addition zu den Sulfonen b8 (III).

STRUCTURAL EFFECTS OF SULFENYL CHLORIDES IN THEIR REACTION WITH 3,3-DISUBSTITUTED 1,2-ALKADIENYLPHOSPHONIC DICHLORIDES

Abstract The reaction of 3,3-disubstituted allenylphosphonic dichlorides with sulfenyl chlorides in the presence of sulfur dioxide proceeds with formation of mixtures of 2,5-dihydro-1,2-oxaphospholes and 1,2-adducts. The influence of hydrocarbon substituent in the electrophilic sulfur on the reaction road has been investigated in detail.

ChemInform Abstract: TRANSPORT PROPERTIES OF ALUMINUM CHLORIDE‐THIONYL CHLORIDE‐BASED ELECTROLYTES

AbstractAus den Leitfähigkeiten, Viskositäten und Dichten der AlCh‐SOCIZ‐Elektrolytlösungen mit und ohne SO2 und Ssowie LiCl in verschiedenen Konzentrationen als Funktion der Temp. werden Informationen zur Struktur und den Transportweisen erhalten.

Selective absorption of hydrogen chloride from flue gases in the presence of sulfur dioxide

AbstractDetailed results of static and dynamic experiments to determine the vapor‐liquid equilibrium for HCl and the co‐absorption of hydrogen chloride and sulfur dioxide in concentrated solutions of calcium chloride.

Transport Properties of Aluminum Chloride‐Thionyl Chloride‐Based Electrolytes

Conductance, viscosity, and density of electrolyte solutions with and without sulfur dioxide and sulfur and varying concentration of lithium chloride have been determined as a function of temperature. While the data on system can be interpreted in terms of solute‐solvent interaction forming adducts, those in the presence of sulfur dioxide and lithium chloride have been interpreted in terms of ion‐ion and ion‐solvent interactions and equilibria involving ion pairs and triple ions with complex anions such as and . Data on energy of activation for conductance and for viscous flow along with Walden product are in agreement with this interpretation. The unusually high electrolytic conductance observed for these concentrated electrolyte solutions and the energy of activation data are interpreted in terms of the hopping mechanism for conductance. The implication of increased complexity of solution structure on mass transport during battery discharge is discussed.

The Development and Use of a Rapid Analytical Technique for Estimation of Free and Potentially Volatile Monoterpene Flavorants of Grapes

A technique has been developed for the rapid assay of monoterpene flavorants of grape juices. Steam distillation of juice at neutrality yielded free aroma compounds of the grape while, at low pH, monoterpenes derived from the polyols and glycosidically bound forms were collected. Reaction of these distillates with a vanillinsulfuric acid reagent gave a color, the intensity of which was proportional to the concentration of monoterpenes in the two fractions. Thus analytical figures for free volatile terpenes (FVT) and potential volatile terpenes (PVT) of the grape were obtained. The presence of sulfur dioxide in juice interfered with the determination, necessitating treatment with H₂O₂ before color development. Other non-monoterpenoid juice constituents did not interfere, except <i>trans</i>-hex-2-en-1-ol, which would have contributed to FVT figures. Experiments with different categories of reference monoterpenes, including polyols and glycoside derivatives, demonstrated that the technique gave quantitative recovery of FVT while yields of PVT were 55 to 80 percent. Solutions containing mixtures of different monoterpene categories on assay gave satisfactory recoveries of FVT and PVT. In a preliminary survey, the assay was applied to samples of mature grapes of several varieties and figures for FVT and PVT correlated with the recognized aroma characteristics of the cultivars examined. The value of the assay was demonstrated in observing the increase in concentration of monoterpene flavor compounds in developing Muscat of Alexandria grapes.

Presence of sulfur dioxide in commonly used bronchodilator solutions

We detected a significant amount of SO 2 released from commercially used bronchodilators, including isoproterenol (Isuprel; Breon Laboratories, Inc., New York, N. Y.), metaproterenol (Alupent; Boehringer Ingelheim, Ridgefield, Conn., or Metaprel; Dorsey Laboratories, Lincoln, Neb.), isoetharine (Bronkosol; Breon Laboratories, Inc., New York, N. Y.), and racemic epinephrine (Micronefrin; Bird Corp., Palm Springs, Calif.). During standard nebulization of these agents, SO 2 concentration varied from 0.1 to 6.0 ppm. These levels are known to be bronchoconstrictive in asthmatic patients. We believe clinicians should be aware of this observation when sulfite-containing bronchodilators are used.

The degradation of folic acid in a model food system and in beer

The rate of degradation of folic acid in the light and in the dark is investigated in a model buffer solution and in beer, with and without the addition of sulphur dioxide. In the model solution, held in the light, sulphur dioxide markedly accelerates the rate of degradation of folic acid whereas, in the dark, it exhibits a protective effect. In beer, the presence of sulphur dioxide has no effect on the degradation of folic acid, whether in the light or the dark. In the model solution, in the presence of sulphur dioxide, only the degradation product p-aminobenzoyl glutamic acid was identified. In the absence of sulphur dioxide and in the beer samples, pterin-6-carboxylic acid was additionally identified as a degradation product.

Degradation of sorbic acid in model food systems

Solutions of sorbic acid are unstable in the presence of sulphur dioxide and light. At pH 2·1 in the presence of excess sulphur dioxide, sorbic acid was totally degraded in 8 days. Sorbic acid was also unstable in solutions of dilute sulphuric acid. Two volatile products from the degradation in sulphur dioxide solution and in dilute sulphuric acid were identified as α-angelica lactone and 2-methyl-5-acetylfuran.

Response of guinea pig respiratory tract to inhalation of submicron zinc oxide particles generated in the presence of sulfur dioxide and water vapor

Guinea pigs were exposed for 3 hr to submicron zinc oxide aerosols generated in the presence of water vapor and 1 ppm sulfur dioxide. After exposure to the aerosol containing 5 mg/m 3 of zinc oxide, the animals developed transient pulmonary edema accompanied by increased permeability of the respiratory epithelium to macromolecules and increased DNA synthesis in the terminal bronchioles, indicated by an elevated labeling index on autoradiographs. Peribronchiolar edema with cellular infiltrates was present after exposure to the aerosol containing 25 mg/m 3 of zinc oxide and significant increases in the labeling index were noted for epithelial cells of the bronchi, bronchioles, and alveoli. The changes coincided with functional abnormalities detected in complementary physiological studies.

Conductance of LiBr solutions in acetonitrile in the presence of sulphur dioxide

The effect of SO 2 on the transport properties of LiBr in acetonitrile is studied by conductometric measurements. The specific conductivity of a 0.08 M LiBr solution rises ca. 2.5 fold upon the addition of 0.4 M SO 2. The physical properties of the solvent, the equivalent conductivity, the Walden number change but insignificantly in this SO 2 concentration range, whereas the association constant decreases considerably. It is concluded that the ion-dipole interaction Br − + SO 2 = SO 2.Br −, which raises the concentration of the conducting species and consequently lowers the apparent association constant, is basically responsible for the enhancement of the specific conductivity of LiBr in the mixed solvent acetonitrile with SO 2, used currently in practical Li/SO 2 batteries.

Atmospheric Corrosion Initiation by Sulphur Dioxide and Particulate Matter: II. Characterisation and corrosivity of individual particulate atmospheric pollutants

This research has involved investigation of the simulated atmospheric corrosion of zinc, aluminium and especially iron in situations where particulate pollutants initiate attack at various relative humidities, in the presence and absence of sulphur dioxide. Metal surfaces holding small population densities of particulate material. collected at sites near well-defined sources in rural. industrial and marine locations. have been examined directly and after exposure in simple humidity cabinets. or in a specially designed cellfor in situ observation. Additionally. SEM/EDAX examination has assisted in identifiying the nature and corrosivity of the individual particles. The four most aggressive species were salt and salt/sand from marine or de-iced locations. the emitted ash from iron smelters. plume ashfrom municipal incinerators and coal mine dusts. In each case the corrosiveness was associated with the presence of chloride ions and/or sulphur compounds. Other particulate types. such as fly ashes. had more limited corrosivity. Thus. corrosion was promoted in the vicinity of coal ash in the presence of sulphur dioxide. whilst oil fly ash was relatively non-corrosive even in the presence of sulphur dioxide. Considering the much higher inorganic content of coal fly ash, and the greater porosity of oil fly ash. this suggests that the corrosion mechanism depends upon the catalytic promotion of sulphate formation from sulphur dioxide by inorganic species, such as Fe2+ and Mn2+ ions, which then promotes the anodic reaction, and not simply the absorbed presence of sulphur dioxide per see Chalk particles were non-corrosive even in the presence of sulphur dioxide, due perhaps to the removal of sulphur dioxide as insoluble sulphite/sulphate. The desirability of controlling the emission or distribution of particulates from certain plants is indicated.

Oxygenation with molecular oxygen. Thermal and photochemical epoxidation of propylene in the presence of sulfur dioxide in acetonitrile at ambient temperature

Oxygenation with molecular oxygen. Thermal and photochemical epoxidation of propylene in the presence of sulfur dioxide in acetonitrile at ambient temperature

Measurement of ozone in air in the presence of sulfur dioxide and nitrogen oxides

Measurement of ozone in air in the presence of sulfur dioxide and nitrogen oxides

Effects of sulphur dioxide and ozone, singly or in combination, on membrane permeability

The effects of 0.15 ppm sulphur dioxide and (or) 0.15 ppm ozone on membrane permeability, measured by electrical conductivity of solute leakage, were determined for soybean, white bean, cucumber, and radish. Solute leakage increased significantly prior to visible injury for soybean and white bean exposed to 0.15 ppm ozone alone. This results in water-soaked lesions on the upper leaf surface prior to visible coloured necrotic lesions and is representative of a "leaky" plasmalemma. The sulphur dioxide – ozone mixture did not increase solute leakage above that of the control for white bean and soybean. Therefore, the presence of sulphur dioxide, in combination with ozone, attenuates or reduces the effects of ozone on increasing membrane permeability of white bean and soybean. Ozone alone did not affect membrane permeability in cucumber and radish. The sulphur dioxide – ozone mixture, which produced more injury than ozone alone, did increase membrane permeability temporarily for radish and cucumber but this occurred only after visible injury symptoms appeared. Overall, the effects of the pollutants singly or in combination on membrane permeability appear to offer an explanation of differences in species responses.