Sulfur-dioxide/water equilibria between 0° and 50°C: An examination of data at low concentrations

1982 ◽  
pp. 187-195 ◽  
Author(s):  
Howard G. Maahs
Keyword(s):  
Sulfur Dioxide ◽  
Low Concentrations

The Interaction of Sulfur and Sulfur Compounds with Olefinic Substances. VII. Low-Temperature Sulfuration of Trialkylethylenes with Hydrogen Sulfide-Sulfur Dioxide and with a Sulfur-Zinc Dithiocarbamate System

1955 ◽  
Vol 28 (2) ◽  
pp. 470-479
Author(s):  
E. H. Farmer ◽  
J. F. Ford ◽  
J. A. Lyons
Keyword(s):  
Zinc Oxide ◽  
Hydrogen Sulfide ◽  
Sulfur Dioxide ◽  
Low Temperature ◽  
Room Temperature ◽  
Cross Linking ◽  
Sulfide Sulfur ◽  
Tetramethylthiuram Disulfide ◽  
Zinc Compounds ◽  
Low Concentrations

Abstract The sulfuration of trialkylethylenes with hydrogen sulfide-sulfur dioxide at 0° C (Peachey process) results in disubstitutive cross-linking of the olefins, yielding dialkenyl tetrasulfides. At higher temperatures, substitutive-additive cross-linking occurs, and alkyl alkenyl polysulfides are formed. Dialkenyl tetrasulfides are similarly formed by causing the olefin to react with sulfur at room temperature in the presence of zinc oxide and zinc dibutyldithiocarbamate, low concentrations of hydrogen sulfide acting as a catalyst for this reaction. At higher temperatures, the reaction is also exclusively disubstitutive, a feature connected with the function of zinc compounds in influencing the cross-linking reaction. The sulfuration of olefins with tetramethylthiuram disulfide at 140° C shows a similar influence of zinc compounds.

Airway Effects of Low Concentrations of Sulfur Dioxide: Dose-Response Characteristics

1984 ◽  
Vol 39 (1) ◽  
pp. 34-42 ◽  
Author(s):  
E. Neil Schachter ◽  
Theodore J. Witek ◽  
Gerald J. Beck ◽  
H. Roland Hosein ◽  
Gene Colice ◽  
...  
Keyword(s):  
Sulfur Dioxide ◽  
Dose Response ◽  
Response Characteristics ◽  
Low Concentrations

scholarly journals A SCHIFF REAGENT OF CALIBRATED SENSITIVITY

1959 ◽  
Vol 7 (2) ◽  
pp. 93-97 ◽  
Author(s):  
HERBERT ELFTMAN
Keyword(s):  
Sulfur Dioxide ◽  
Positive Response ◽  
Spectrophotometric Analysis ◽  
Sulfurous Acid ◽  
Low Concentrations ◽  
Red Color ◽  
Violet Color ◽  
Schiff Reagent ◽  
The One ◽  
Excess Sulfur

The sensitivity of Schiff reagent for the detection of low concentrations of aldehyde increases progressively as the concentration of sulfurous acid in the reagent is lowered. Calibration of sensitivity is readily accomplished by titrating the Schiff reagent against the iodine of Lugol's solution. Stability of Schiff's solution depends on decreasing the evaporation of sulfur dioxide and of retarding the change of sulfite to sulfate. For practical purposes these ends can be achieved by storage in the refrigerator of a solution with greater sulfurous acid content and acidity than the solution used for staining. Evacuation of the excess sulfur dioxide or mixing in proper proportions with used reagent allows the rapid production of a solution of the desired sensitivity. If chemical preservatives are required, 0.5% hydroquinone gives very good results. Spectrophotometric measurement of the colored solutions produced by adding aldehyde to Schiff reagent indicates that at least two distinct compounds may result. The one that is usually mentioned as characteristic of a positive response of aldehyde to the Schiff reagent has a violet color. When the concentration of aldehyde is so low that only a Schiff solution of low sulfurous acid titer will react with it, a red color is produced. Spectrophotometric analysis shows this compound to be different from the original basic fuchsin and validates its use as an endpoint in the reaction of aldehyde with Schiff's reagent.

Calculated sulfur dioxide equilibria at low concentrations between air and water

1977 ◽  
Vol 8 (3) ◽  
pp. 255-262 ◽  
Author(s):  
Martin B. Hocking ◽  
Graham W. Lee
Keyword(s):  
Sulfur Dioxide ◽  
Low Concentrations

CHRONIC OZONE OR SULFUR DIOXIDE EXPOSURES, OR BOTH, AFFECT THE EARLY VEGETATIVE GROWTH OF SOYBEAN

1973 ◽  
Vol 53 (4) ◽  
pp. 875-879 ◽  
Author(s):  
DAVID T. TINGEY ◽  
CARLOS WICKLIFF ◽  
RICHARD A. REINERT ◽  
WALTER W. HECK
Keyword(s):  
Glycine Max ◽  
Sulfur Dioxide ◽  
Plant Growth ◽  
Vegetative Growth ◽  
Ozone Treatment ◽  
Foliar Injury ◽  
Fresh Weight ◽  
Low Concentrations ◽  
Glycine Max L ◽  
Treatment Interaction

Soybean (Glycine max (L.) Merr.) cult Hood and Dare were exposed to low concentrations of ozone or sulfur dioxide, or both, during the first 3 wk of growth. Foliar injury occurred on both cultivars in the ozone and mix treatments. Dare developed more foliar injury than Hood. Plant height, top and root fresh and dry weights, and the dry shoot–root ratios were significantly reduced by the 10-pphm ozone treatment. The mix of 5 pphm ozone plus 5 pphm sulfur dioxide significantly reduced top fresh weight, root fresh and dry weights, and shoot–root ratios. Treatments of 5 pphm ozone, 5 pphm or 20 pphm sulfur dioxide had no significant effects on plant growth. The growth reductions resulting from the ozone–sulfur dioxide mix were greater than the additive reductions of the single gases. The lack of a significant cultivar × treatment interaction indicated that the growth of the two cultivars responded similarly to the various treatments.

Effets of Sulfur Dioxide on Three Eucalyptus Species

1984 ◽  
Vol 32 (2) ◽  
pp. 139 ◽  
Author(s):  
F Murray
Keyword(s):  
Sulfur Dioxide ◽  
Growth Parameters ◽  
Eucalyptus Species ◽  
Continuous Exposure ◽  
Total Chlorophyll ◽  
Foliar Injury ◽  
Visible Injury ◽  
Leaf Chlorophyll ◽  
Low Concentrations ◽  
Chlorophyll Concentrations

Eucalyptus punctata, E. moluccana and E. crebra were exposed continuously to low concentrations of sulfur dioxide, up to 10.1 pphm, for durations of up to 40 days in open-top fumigation chambers. Foliar injury and accelerated leaf senescence were found in E. punctata but no symptoms of visible injury were detected in E. moluccana or E. crebra. Sulfur dioxide exposure significantly depressed leaf chlorophyll concentrations in E. crebra and exposure to 4.3 pphm sulfur dioxide significantly depressed total chlorophyll concentrations in E. moluccana. Sulfur dioxide had no significant effect on leaf chlorophyll in E. punctata. Exposure to sulfur dioxide significantly increased leaf sulfur concentrations in all three species, with the exception of the exposure of E. punctata to 3.8 pphm sulfur dioxide which did not result in foliar sulfur accumulation. Sulfur dioxide had no significant effects on tree growth parameters in E. moluccana or E. crebra. Although all three Eucalyptus species were sensitive to continuous exposure to low concentrations of sulfur dioxide, the response is species-dependent.

Response of Selected Pinusstrobus L. Clones to Fumigations with Sulfur Dioxide and Ozone

1974 ◽  
Vol 4 (1) ◽  
pp. 65-68 ◽  
Author(s):  
Daniel B. Houston
Keyword(s):  
Sulfur Dioxide ◽  
Field Observations ◽  
Ambient Conditions ◽  
White Pine ◽  
Eastern White Pine ◽  
Sensitive Clone ◽  
Low Concentrations ◽  
Two Indices ◽  
Consistent Response ◽  
Tolerant Clones

Response of eastern white pine (Pinusstrobus L.) to ozone (O3) and sulfur dioxide (SO2) was studied utilizing controlled fumigation chambers in the greenhouse. Tolerant and sensitive clones were fumigated for 6 h at concentrations of 5, 10, 30, and 60 parts per hundred million (p.p.h.m.) O3, 2.5, 5, 15, and 45 p.p.h.m. SO2, and 2.5 p.p.h.m. SO2 plus 5 p.p.h.m. O3 in combination. Response was judged by needle elongation and two indices of direct needle damage.Ozone exposures did not produce a consistent response among tolerant and sensitive classes, while injury caused by SO2 and SO2 plus O3 correlated well with field observations of damage under ambient conditions. The most sensitive clone was injured by concentrations of SO2 as low as 2.5 ± 1 p.p.h.m. Sixty percent of the tolerant clones were injured by 5 and 15 p.p.h.m. SO2, and all tolerant material was injured at 45 p.p.h.m. SO2. The interaction of SO2 and O3 at low concentrations was established as more serious than that caused by either pollutant alone at similar levels.

Extractive Spectrophotometric Determination of Trace Amounts of Sulfur Dioxide in Air

1992 ◽  
Vol 75 (6) ◽  
pp. 1006-1010 ◽  
Author(s):  
B S M Kumar ◽  
N Balasubramanian
Keyword(s):  
Sulfur Dioxide ◽  
Absorption Coefficient ◽  
Spectrophotometric Method ◽  
Coefficient Of Variation ◽  
Formaldehyde Solution ◽  
Low Concentrations ◽  
Color System ◽  
Isopentyl Alcohol ◽  
Sensitive Spectrophotometric Method

Abstract A sensitive spectrophotometric method was developed for the determination of trace amounts of sulfur dioxide (SO2) in air after SO2 has been fixed in a buffered formaldehyde solution. The reaction of iodate with the fixed SO2 in the presence of an acid and an excess of chloride leads to the formation of ICI2 ions. The resulting ICI2 species forms an ionpair with pararosaniline cation; the product is extracted into isopentyl alcohol and measured spectrophotometrically at 560 nm. The color system obeys Beer's law over the range 0-40 μg SO2. The color is stable for 72 h from the time of extraction. The molar absorption coefficient of the color system is 4.5 x 103Lmol"1cm"1. The coefficient of variation is 3.6% for 10 determinations at 20 μg SO2. The effect of interfering gases on the determination is discussed. The method was applied to the determination of SO2 at low concentrations, and the results obtained were compared with the widely used West and Gaeke method. The method can be used to determine as low as 2 μg S02

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