Chlorinated polyaromatic hydrocarbons

Chlorinated hydrocarbons, determination of 244 Chlorinated polyaromatic hydrocarbons, determination of 132 Chlorinated insecticides,... 

This publication provides several examples of the use of solid-phase extractions for separating analytes from their matrices. Some of the examples included are caffeine from coffee, polyaromatic hydrocarbons from water, parabens from cosmetics, chlorinated pesticides from water, and steroids from hydrocortisone creams. Extracted analytes maybe determined quantitatively by gas (GC) or liquid chromatography (LG). 

Alkylphenols, ammonia, asbestos, chlorinated paraffins, 4-chloroaniline, cyanide, detergents, di- -butyl phthalate, polyaromatic hydrocarbons (PAHs e.g. anthracene, benzopyrene, methylcholanthrene, /i-naphthoflavone), nitrate, nitrite, petroleum oil, phenol, pentachlorophenol, 4-nitrophenol, dinitro-o-cresol, polychlorinated biphenyls (PCBs especially coplanar), polychlorinated dioxins, polybrominated naphthalenes, /i-sitosterol, sulfide, thiourea, urea, acid water, coal dust... 

Chlorinated solvents, polyaromatic hydrocarbons, and other organics can be resistant to in situ biodegradation or may take exceedingly long periods of time to degrade in many subsurface settings. 

Petrick et al. [375] extracted up to 2000 dm3 of Atlantic Ocean waters using various solid resins. Down to 5 ng/dm were determined of chlorinated biphenyls, HCB, DDE, and polyaromatic hydrocarbons in samples taken at depths down to 4000 metres. 

In non-saline sediments aliphatic and polyaromatic hydrocarbons, phthalate esters carboxylic acids, uronic acid aldoses chloroaliphatics haloaromatics chlorophenols chloroanisoles polychlorobiphenyls polychlorodibenzo-p-dioxins poychlorodibenzofurans various organosulphur compounds, chlorinated insecticides, organophosphorus insecticides mixtures of organic compounds triazine herbicides arsenic and organic compounds of mercury and tin. 

Japenga et al. [56] determined polychlorinated biphenyls and chlorinated insecticides in River Elbe estuary sediments by a procedure in which the sediments were pretreated with acetic acid, mixed with silica and Soxhlet-extracted with benzene/hexane. Humic material and elemental sulphur were removed by passing the extract through a chromatographic column containing basic alumina, on which sodium sulphite and sodium hydroxide were adsorbed. Silica fractionation was followed by gas chromatography to analyse chlorinated pesticides, polychlorinated biphenyls and polyaromatic hydrocarbons. Recovery experiments with standard solutions gave recoveries of 90-102%. 

Polychlorinated dibenzodioxins (PCDDs) Polychlorinated dibenzofurans (PCDFs) Polychlorinated biphenyls (PCBs) Polyaromatic hydrocarbons (PAHs) Pentachlorophenol Short chain chlorinated paraffins Hexachlorocyclohexane isomers Mercury and organic mercury compounds Cadmium... 

According to the vendor, this technology is capable of removing chlorinated hydrocarbons, aliphatic hydrocarbons, aromatics, benzene, toluene, xylene, carbon tetrachloride, vinyl chloride, dichloromethane, and trichloroethane. Polychlorinated biphenyls (PCBs), polyaromatic hydrocarbons (PAHs), and volatile inorganic solvents can also be removed. The technology is currently in use and is commercially available. 

According to the vendor, ECGO has been used to treat a wide range of organic compounds including benzene, toluene, ethylbenzene, and xylene (BTEX), chlorinated solvents, pesticides, total petroleum hydrocarbons (TPHs), phenols, polyaromatic hydrocarbons (PAH), and nitroamines. 

Supercritical C02 has also been tested as a solvent for the removal of organic contaminants from soil. At 60°C and 41.4 MPa (6,000 psi), more than 95% of contaminants, such as diesel fuel and polychlorinated biphenyls (PCBs), may be removed from soil samples (77). Supercritical C02 can also extract from soil the following hydrocarbons, polyaromatic hydrocarbons, chlorinated hydrocarbons, phenols, chlorinated phenols, and many pesticides (qv) and herbicides (qv). Sometimes a cosolvent is required for extracting the more polar contaminants (78). 

The second stage in the chlorination, which is endothermic, leads to higher molecular weight products, from C2 hydrocarbons up to polyaromatic hydrocarbons (PAH). 

PAH PAJ PAO PCBs Polyaromatic hydrocarbons. Petroleum Association of Japan. Poly-a-olefin base stock of various viscosity classifications. Any of the chlorinated derivatives of biphenyl (also called diphenyl). 

Use of granular activated carbon (GAC) is considered to be the best currently available technology for removing low-solubility contaminants such as disinfection by-products (usually from chlorination) that include trihalomethanes (THM), detergents, pesticides, herbicides, polyaromatic hydrocarbons, and some trace metals. The amendments to the Safe Drinking Water Act. state that other treatment technologies must be at least as effective as GAC [66]. 

We hypothesized that the above treatise of DDL interactions in the presence of an electrical field is a viable model for the explanation of enhanced oxidation-reduction in clay-electrolyte systems. Electrolytic transformations of selected chlorinated hydrocarbons (CHCs) and polyaromatic hydrocarbons (PAHs) have been demonstrated successfully in water and wastewater (Franz, Rucker, and Flora, 2002 Pulgarin et al., 1994). There has been field and laboratory evidence that these transformations can also take place in porous media (Banarjee et aL, 1987 Pamukcu, Weeks, and Wittle, 2004 Alshawabkeh and Sarahney, 2005 Pamucku, Hannum, and Wittle, 2008). As discussed previously, faradic reactions do take place on clay particle surfaces when current pass in the pathways of the DDLs (Grahame, 1951, 1952). Hence, external supply of electrical energy can help drive favorable oxidation-reduction reactions in contaminated clays not only in the bulk fluid but also on clay surfaces, as well as on where most of the contaminants tend to reside because of adsorption or exchange. 

Ability to convert hard-to-degrade organics such as chlorinated organics and heavy organics (e.g., polyaromatic hydrocarbons) into more volatile organic compounds ... 

To prevent oxidation, either ascorbic acid or sodium thiosulfate is often added to samples to remove free chlorine that could otherwise form trichloro-methane. Polyaromatic hydrocarbons (PAHs), in particular benzo[a]-pyrene, are unstable in chlorinated water and sodium thiosulfate is added to preserve the analytes from degradation by chlorine. To ensure stability of the PAH analytes, the water sample is also acidified, again showing that often a single preservative is not always effective for some analytes. 

Further recent developments in fiber SPME have extended applications to compounds with low volatilities and/or low thermal stability. Thus, fiber-(or tube-) based SPME-LC has a considerable future potential, particularly as it has been recognized that GC capillary columns (available with a very wide range of internal coatings) can be used for this purpose. Samples are pumped through the tube using a micropump and then eluted onto the EC column using appropriate solvents. Applications of in-tube SPME (in combination with LC) include phthalates, chlorinate phenoxy acid herbicides, tributyl tin compounds, polyaromatic hydrocarbons (PAEIs), and polar aromatic compounds in water. 

---