Hydrocarbons, Volatile halogenated

The question as to whether a flame retardant operates mainly by a condensed-phase mechanism or mainly by a vapor-phase mechanism is especially comphcated in the case of the haloalkyl phosphoms esters. A number of these compounds can volatilize undecomposed or undergo some thermal degradation to release volatile halogenated hydrocarbons (37). The intact compounds or these halogenated hydrocarbons are plausible flame inhibitors. At the same time, thek phosphoms content may remain at least in part as relatively nonvolatile phosphoms acids which are plausible condensed-phase flame retardants (38). There is no evidence for the occasionally postulated formation of phosphoms haUdes. Some evidence has been presented that the endothermic vaporization and heat capacity of the intact chloroalkyl phosphates may be a main part of thek action (39,40). 

Barkley J, Bunch J, Bursey JT, et al. 1980. Gas chromatography mass spectrometry computer analysis of volatile halogenated hydrocarbons in man and his environment. A multimedia environmental study. Biomed Mass Spectrom 7 139-147. 

Jung WT, Fujita M, Sohn DH. 1992. Levels of volatile halogenated hydrocarbons in Tokyo rain and their seasonal, time-series changes. Eisei Kagaku 38 490-497. 

MacKenzie Peers A. 1985. The determination of methyl bromide in air-method 8. In Fishbein L, O Neill IK, ed. Environmental carcinogens selected methods of analysis. Vol. 7. Some volatile halogenated hydrocarbons. Lyon France International Agency for Research on Cancer, 227-233. 

Environmental exposure to chloroform in humans probably represents a combination of inhalation exposure (from the air polluted with volatile halogenated hydrocarbons) and oral exposure (from... 

Hajimiragha H, Ewers U, Jansen-Rosseck R, et al. 1986. Human exposure to volatile halogenated hydrocarbons from the general environment. Int Arch Occup Environ Health 58 141-150. 

Hovorka, S. and Dohnal, V. Determination of air-water partitioning of volatile halogenated hydrocarbons by the inert gas stripping method, J. Chem. Eng. Data, 42(5) 924-933, 1997. 

Huber M, Estermann G, Bonn G. 1988. Analysis of volatile halogenated hydrocarbons on the ppq scale. Fresenius Z Anal Chem 331 486-489. 

Occupationally, liver injury is most likely to occur following exposure to vapors of volatile halogenated hydrocarbons (such as chloroform, carbon tetrachloride, and bromobenzene), which may enter the bloodstream via the pulmonary route. However, hepatotoxins may enter the gastrointestinal tract, and hence the liver, in the form of fine particles. They are inhaled, then expelled from the bronchi or trachea into the oral cavity, and swallowed with saliva. 

Vol. 7. Some Volatile Halogenated Hydrocarbons (lARC Scientific Publications No. 68). Edited by L. Fishbein I.K. O Neill (1985)... 

Piet, G. J., Luijten, W.C.M.M. van Noort, P.C.M. (1985a) Dynamic head-space determination of volatile organic halogen compounds in water. In Fishbein, L. O Neill, I. K., eds. Environmental Carcinogens. Selected Methods of Analysis, Vol. 7, Some Volatile Halogenated Hydrocarbons (lARC Scientific Publications No. 68), Lyon, lARC, pp. 331-343... 

For an assessment of the global distribution of persistent volatile halogenated hydrocarbons, the solubility and activity coefficients of such compounds in natural waters need to be known. Warner and Weiss (1985) have determined the solubilities of dichlorodifluoromethane (Freon 12) at 1 bar partial pressure at various temperatures in freshwater and in seawater (35.8%o salinity) ... 

T HE PRESENCE OF ORGANIC CONSTITUENTS IN DRINKING WATER has been known for many years because these substances were found to influence the taste, color, and odor of drinking waters (J). The organic constituents consist of compounds of both natural and industrial origin. The natural ones compose the major portion and include mainly undefined fulvic and humic acids (2). For the industrial ones, most attention has been paid so far to the volatile nonpolar compounds. In part, this situation is due to analytical (technical) restrictions and to the growing awareness (3, 4) that volatile halogenated hydrocarbons are introduced as a result of a chlorine treatment. 

Yamamoto H, Yokouchi Y, Otsuki A, Itoh H (2001) Depth Profiles of Volatile Halogenated Hydrocarbons in Seawater in the Bay of Bengal. Chemosphere 45 371... 

Purgeable Volatile Halogenated Hydrocarbons and Their Characteristic Masses... 

Table 2.9.1 lists some commonly used volatile halogenated hydrocarbons. Most of these are U.S. EPA listed pollutants. The term volatile indicates that these substances may be extracted by purge and trap technique. This also includes a few compounds of relatively moderate boiling range, responding adequately to the purge and trap method. The characteristic masses for GC/MS determination are also presented in the table. 

Synonyms dichloromethane Formula CH2C12 MW 84.94 CAS [75-09-2] a volatile halogenated hydrocarbon widely used as a solvent boils at 40°C vapor pressure 349 torr at 20°C density 1.323 g/mL at 20°C solubility in water, very low (1.3%) miscible in organic solvents nonflammable. 

Hagenmaier et al. [59] have described a method for the quantitative gas chromatographic determination of volatile halogenated hydrocarbons in lake water samples. Sample enrichment is effected by liquid-liquid extraction with pentane, followed by separation on a capillary gas-liquid chromatographic column, with electron capture detection. A 1 25 pentane-water ratio was employed in conjunction with a standard solution of a reference compound (1-bromobutane) for estimating extraction... 

Modern inhalation anesthetics are nonexplosive agents that include the gas nitrous oxide as well as a number of volatile halogenated hydrocarbons. As a group, these agents decrease cerebrovascular resistance, resulting in increased perfusion of the brain. They cause bronchodilation and decrease minute ventilation. Their clinical potency cannot be predicted by their chemical structure, but potency does correlate with their solubility in lipid. The movement of these agents from the lungs to the different body compartments depends upon their solubility in blood and various tissues. Recovery from their effects is due to redistribution from the brain. 

Riccio E, Griffin A, Mortelmans K, et al. 1983. A comparative mutagenicity study of volatile halogenated hydrocarbons using different metabolic activation systems. Environ Mut 5 472. 

At this point, the sample is analyzed by gas chromatography (GC), the analytical method of choice for volatile halogenated hydrocarbons. Information on the analysis of these samples by GC is presented in Section 6.2, with a discussion of the advantages and disadvantages of each method. The technique of Antoine et al. (1986) showed a 5% variance on a series of 2 ppb spiked samples, and the analysis had a linear response ranging from 0.5 to 50 ppb. Although infra-red spectrometry has less sensitivity than electron capture detectors (ECD), Hall electroconductivity detectors (HECD), and mass spectrometrlc detectors (MS), it has been used to quantify the levels of... 

In 1954, Ethylene Dibromide (EDB) was introduced as a product for the preplant treatment of agricultural fields to control nematodes and it is still used worldwide. EDB is a volatile, halogenated hydrocarbon that is usually marketed as a liquid. The liquid is injected 15 to 30 centimeters beneath the soil surface with a tractor driven chisel tool where the vapors permeate soil air spaces and kill the... 

ISO 10381-2 (1994) Soil quality - Sampling - Part 2 Guidance on the design of sampling techniques. ISO 10381 (1997) Water quality - Determination of highly volatile halogenated hydrocarbons - Gas-chromatographic methods. 

ISO 15009 2002 Soil quality - Gas chromatographic determination of the content of volatile aromatic hydrocarbons, naphthalene and volatile halogenated hydrocarbons - Purge-and-trap method with thermal desorption. 

Block 2 - the heavy metal group (e.g. arsenic, mercury, cadmium) and lightly volatile halogenated hydrocarbons (e.g. tetrachloroethylene), the broad group of pesticide substances (e.g. triazine, phenoxy alkane carbon acids) and polycyclic aromatic hydrocarbons (PAHs). 

Chemical dechlorination processes use reduction reagents to remove chlorine atoms from hazardous chlorinated molecules to leave less hazardous compounds. Dechlorination can be used to treat soils and waste contaminated with volatile halogenated hydrocarbons, polychlorinated biphenyls and organochlorine pesticides. 

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