Ethylene dibromide determination

Rowe VK, Spencer HC, McCollister DD, et al. 1952. Toxicity of ethylene dibromide determined on experimental animals. Industrial Hygiene and Occupational Medicine 6 158-173. 

Repeat the boiling point determination with the following pure liquids (a) carbon tetrachloride, A.R. (77°) (6) ethylene dibromide (132°) or chlorobenzene (132°) (c) aniline, A.R. (184-6°) and (d) nitrobenzene, A.R. (211°). An air condenser should be used for (c) and (d). Correct the observed boiling points for any appreciable deviation from the normal pressure of 760 mm. Compare the observed boiling points with the values given in parentheses and construct a calibration curve for the thermometer. Compare the latter with the curve obtained from melting point determinations (Section 111,1). 

Quantitative Analysis of All llithium Initiator Solutions. Solutions of alkyUithium compounds frequentiy show turbidity associated with the formation of lithium alkoxides by oxidation reactions or lithium hydroxide by reaction with moisture. Although these species contribute to the total basicity of the solution as determined by simple acid titration, they do not react with allyhc and henzylic chlorides or ethylene dibromide rapidly in ether solvents. This difference is the basis for the double titration method of determining the amount of active carbon-bound lithium reagent in a given sample (55,56). Thus the amount of carbon-bound lithium is calculated from the difference between the total amount of base determined by acid titration and the amount of base remaining after the solution reacts with either benzyl chloride, allyl chloride, or ethylene dibromide. 

The various fumigants often exhibit considerable specificity toward insect pests, as shown in Table 8. The proper choice for any control operation is determined not only by the effectiveness of the gas but by cost safety to humans, animals, and plants flammabdity penetratabdity effect on seed germination and reactivity with furnishings. The fumigants may be used individually or in combination. Carbon tetrachloride has been incorporated with carbon disulfide, ethylene dichloride, or ethylene dibromide to decrease flammability, and carbon dioxide is used with ethylene oxide for the same purpose. 

In the evaluation of ethylene dibromide as a soil fumigant, a sensitive procedure was needed for determining concentrations lower than 0.2 mg. per cubic inch in soil. When the method of Brenner and Poland was used, addition of a small quantity of acetic acid considerably increased the percentage of ethylene dibromide recovered. 

Dillon, Young, and Lucas (5) described a method for determining dibromobutanes in 99% methanol. Dillon ( ) expanded this work to include a procedure for determining ethylene dibromide. Brenner and Poland (1) described a procedure in which they determined 1.000 mg. of ethylene dibromide with a recovery of 65.8%. Equations 1 and 2 show the main reactions that occur. 

Abdel-Kader MHK, Peach ME, Stiles DA. 1979. Determination of ethylene dibromide in fortified soils by molecular emission cavity analysis using a modified extraction process. J Assoc Off Anal Chem 62 114-118. 

Bielorai R, Alumot E. 1965. Determination of ethylene dibromide in fumigated feeds and foods by gas-liquid chromatography. J Sci Food Agric 16 594-596. 

Clower M Jr, McCarthy JP, Carson LJ. 1986. Comparison of methodology for determination of ethylene dibromide in grains and grain-based foods. J Assoc Off Anal Chem 69 87-90. 

Kirby KW, Tremmel H, Keiser JE. 1980. Determination and metabolism of ethylene dibromide in minipigs. Bull Environ Contam Toxicol 25 774-777. 

Pranoto-Soetardhi LA, Rijk MAH, DeKruijf N, et al. 1986. Automatic headspace sampling for determination of ethylene dibromide residues in cereals. Int J Environ Anal Chem 25 151-159. 

Scudamore KA. 1985. Gas chromatographic determination of chloroform, carbon tetrachloride, ethylene dibromide and trichloroethylene in cereal grains after distillation. lARC Sci PubI 68 361-367. 

Van Rillaer WG, Beernaert H. 1985. Determination of residual ethylene dibromide in cereals by glass capillary gas chromatography. Z Lebensm Unters Forsch 180 284-288. 

The lARC has determined that there is inadequate evidence in humans but sufficient evidence in experimental animals for the carcinogenicity of ethylene dibromide. An overall evaluation of probably carcinogenic to humans is given. A threshold limit exposure limit has not been assigned by ACGIH. 

The World Health Organization has determined that there are no adequate data to permit recommendation of a health-based guideline value for ethylene dibromide in drinking-water (WHO, 1993). 

Ethylene dibromide caused a dose-dependent increase in liver DNA alkaline-labile sites and single-strand breaks (as determined by alkaline elution assay) in female Sprague-Dawley rats. It was positive in an unscheduled DNA synthesis assay in rat spermatocytes in vitro but was negative in the spermatocytes of rats dosed in vivo. Ethylene dibromide gave positive results in an amphibian Pleurodeles yvaltl) mieronueleus test but gave negative results in dominant lethal tests. 

Flame Studies. The effects of ethylene dibromide, bromoform, and chloroform on flame speeds of several hydrocarbons were examined. These studies were carried out with 5% molar concentration of the halogen compounds in each hydrocarbon. All the experiments were carried out under identical conditions, and the results reported in Table I are the mean of at least three separate determinations. 

Quantitative Analysis of Alkyllithium initiator Solutions. The amount of carbon-bound lithium is calculated from the difference between the tolal amount of base determined by acid titration and the amount of base remaining after the solution reacts with either benzyl chloride, ally I chloride, or ethylene dibromide. 

Figure 2. Boiling point vs. pressure for ethylene dibromide as determined by the differential thermal analyzer. Heating rate = 15° C. per minute vertical scale 0.1 °C. per division...

Amts, R. R., Seila, R. L., and Bufalini, J. J. (1989). Determination of Room Temperature OH Rate Constants for Acetylene, Ethylene Dichloride, Ethylene Dibromide, p-Dichlorobenzene, and Carbon Disulfide. JAPCA 39, 453-460. 

Amts RR, Seila RL, Bufalini JJ. 1989. Determination of room temperature OH rate constants for acetylene, ethylene dichloride, ethylene dibromide, p-dichlorobenzene, and carbon disulfide. JAPCA 39 453-460. 

The rate-determining step was identified as an inner-sphere electron transfer between Bi2Co(I) and the all l dibromide, Eq. (15b). This electron transfer may alternatively be due to a concerted E2 mechanism. Ultramicroelectrode voltammetry was used to determine the kinetics in AOT-isooctane-water microemulsions. The polar vitamin B12 resides entirely in the water pools, whereas the substrates are present primarily in the continuous oil phase. The rate constant k was determined from the increase of the limiting current caused by the addition of the substrates [ethylene dibromide (EDB), 1,2-dibromobutane (DBB), and /rarw-l,2-dibromocyclohexane (/-DBCH)] to the AOT microemulsion. As shown in Table 5 [36], the apparent rate constants were three orders of magnitude lower in the microemulsion than in the acetonitrile-water system. The rate decrease was attributed to the spatial separation of the catalyst and the substrate [36]. 

In consultation widi DOE and the Plumes Focus Area, representative target VOCs and SVOCs were determined. Potential VOCs and SVOCs present at various DOE facilities include TCE, trichloroediane (TCA), 1,2-ethylene dibromide (EDB), CCU, CHCI3, vinyl chloride (VC), 1,1- chloroethylene (DCE), 1,1,2,2-tetrachloroetfaylene (PCE), and polychlorinated b henyls (PCBs). After determination of the target compounds, the subsequent tasks focused on the integrated in-well sonication/in-well vapor str ing, and biodegradation system. 

The actual density of a solid substance, even of a relatively small individual crystal, may be measured by determining the density of an inert liquid mixture in which the crystal remains just suspended. Examples of a convenient group of miscible organic liquids for many inorganic salts include chloroform (1492kgm at 20 °C), carbon tetrachloride (1594), ethyl iodide (1930), ethylene dibromide (2180), bromoform (2890) and methylene iodide (3325). 

The hydrolysis rate constant for ethylene dibromide at pH 7 and 25 °C was determined to be 9.9 X 10 /hour, resulting in a half-life of 8.0 years (Ellington et al., 1988). At pH 5 and temperatures of 30, 45 and 60°C, the hydrolysis half-lives were 180, 29 and 9 days, respectively. When the pH was raised to pH 7, the half-lives increased slightly to 410, 57 and 11 days at temperatures of 30, 45 and 60°C, respectively. At pH 9, the hydrolysis half-lives were nearly identical to those determined under acidic conditions (Ellington et al., 1986). 

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