Showing papers on "Aromatic hydrocarbon published in 1976"

Accumulation and release of petroleum-derived aromatic hydrocarbons by four species of marine animals

Abstract: When exposed to oil-contaminated seawater, marine animals accumulate a wide variety of petroleum hydrocarbons in their tissues. Generally, the aromatic hydrocarbons are accumulated to a greater extent and are retained longer than the alkanes. In all species tested, accumulation of aromatic hydrocarbons appears to be dependent primarily on a partitioning of the hydrocarbons between the exposure water and the tissue lipids. Current evidence indicates that binding of hydrocarbons to tissue lipids is by hydrophobic interactions and not by covalent bonding. Bioaccumulation factors (tissue: water concentration ratio) increase in proportion to the increase in molecular weight of the aromatic hydrocarbons. When returned to oil-free seawater, marine animals rapidly release the accumulated hydrocarbons from their tissues. Release rates are species-dependent. Shrimp and fish, which can metabolize aromatic hydrocarbon, release them more rapidly than clams and oysters, which apparently lack the detoxifying enzymes. Release of hydrocarbons to background or undetectable levels requires from 2 to 60 days. The high molecular weight aromatic hydrocarbons are released more slowly than the low molecular weight hydrocarbons.

Fate of petroleum hydrocarbons taken up from food and water by the blue crab Callinectes sapidus

Abstract: Radiolabeled paraffinic and aromatic hydrocarbons, including benzopyrene, fluorene, naphthalene, methylnaphthalene, methylcholanthrene, hexadecane, heptadecane and dotriacontane, were taken up from food and water by the blue crab Callinectes sapidus. In 2 days, approximately 10% of the benzopyrene and fluorene were taken up from the water when their concentrations were 2.5 and 30 μg/l, respectively. When given food with radiolabeled hydrocarbons, 2 to 10% of the hydrocarbons were assimilated by the carbs, with the remainder excreted. After uptake of hydrocarbon from water or food, a major pathway for the elimination of hydrocarbon and metabolites was through fecal material. All hydrocarbons used in the study were metabolized, with similar rates for both paraffinic and aromatic hydrocarbons. More than 50% of the radioactivity assimilated by the crabs was in the hepatopancreas, suggesting that the hepatopancreas was the site of hydrocarbon metabolism. Twenty-five days aftex exposure to radiolabeled hydrocarbons, radioactivity was found only in the hepatopancreas. The hepatopancreas contained highly polar hydrocarbon metabolites, including dihydroxy-compounds and their conjugates, while blood contained both monohydroxy-and dihydroxy-compounds. No evidence was found of storage of hydrocarbons by any of the crab tissues.

Genetic differences in 2-acetylaminofluorene mutagenicity in vitro associated with mouse hepatic aryl hydrocarbon hydroxylase activity induced by polycyclic aromatic compounds.

Abstract: The genetically mediated difference in aromatic hydrocarbon-inducible hepatic aryl hydrocarbon (benzo[ a ]pyrene) hydroxylase activity is associated with the metabolic activation of 2-acetylaminofluorene to a mutagen in vitro by liver fractions. With the use of"responsive" C57BL/6N and "nonresponsive" DBA/2N inbred strains and offspring from the appropriate crosses, the aromatic hydrocarbon-inducible hydroxylase activity appears to be expressed as an autosomal dominant trait, whereas 2-acetylaminofluorene mutagenicity in vitro appears to be expressed additively. With N -hydroxy-2-acetylaminofluorene added in vitro , no metabolic activation is necessary for mutagenesis to occur; however, mutagenicity is enhanced 20-40-fold in the presence of liver fractions. The metabolic activation of N -hydroxy-2-acetylaminofluorene to a frameshift mutagen in vitro is not associated with the genetically mediated difference in aromatic hydrocarbon responsiveness. We therefore suggest that the rate-limiting step of 2-acetylaminofluorene mutagenesis is its activation by cytochrome P1450 to the N -hydroxy derivative, which is metabolized further to a much more mutagenic intermediate by a reaction independent of cytochrome P1450-possibly a deacetylation reaction. ACKNOWLEDGMENT We appreciate very much the expert technical assistance of Roy C. Levitt.

Structure of 7,12-dimethylbenz(a)anthracene-guanosine adducts

Abstract: Arene oxides have been proposed as the reactive intermediates in the process of carcinogenesis induced by polycyclic aromatic hydrocarbons. The present study defines the structures of four guanosine adducts formed by the reaction of 7,12-dimethylbenz[a]anthracene-5,6-oxide with polyguanylic acid. The modified polymer was hydrolyzed to nucleotides and the hydrophobic guanosine adducts separated from unmodified guanosine by LH-20 column chromatograhy. The adducts were further resolved into four components (I-IV) by reverse phase high pressure liquid chromatography. Analysis of the ultraviolet, circular dichroism, mass, and proton magnetic resonance spectra of these compounds, or their acetate and free base derivatives, indicates that in all four compounds the aromatic hydrocarbon is present on the 2 amino group of guanine. Compounds I and IV, and II and III constitute diastereoisomeric pairs, respectively. In the I and IV pair, the adducts result from addition at the 6 position of the original dimethylbenz[a]anthracene oxide, whereas in the II and III pair, the addition occurs at the 5 position. Indirect evidence suggests that trans opening of the oxide occurred in all cases but this remains to be established.

Quenching of aromatic hydrocarbon singlets and aryl ketone triplets by alkyl disulfides

Abstract: Quenching of aromatic hydrocarbon fluorescence and aryl ketone phosphorescence by alkyl disulfides has been investigated. Two quenching mechanisms, charge-transfer stabilized exciplex formation and electronic energy transfer, have been considered. Charge transfer appears to be unimportant for the aromatic hydrocarbons and ketones studied. Endothermic singlet-singlet energy transfer is more efficient than predicted by the Arrhenius equation. Excitation of vibrationally excited ground-state disulfide molecules provides a possible explanation for efficient endothermic quenching. Low-temperature uv spectroscopy indicates that the long-wavelength absorption of disulfides consists predominately of hot-band transitions.

Biodegradation of polynuclear aromatic hydrocarbon pollutants by soil and water microorganisms. Research report

Abstract: Polynuclear aromatic hydrocarbons (PNAs) are widely distributed in natural soils and waters and further are introduced into the environment by, eg, oil spills and coal conversion processes Since these toxic chemicals not only persist in nature but also can be converted into a carcinogenic agent in the animal, their complete removal or transformation to a harmless species is important This study (1) delineated the structural limits of PNA degradability by measuring initial rates of aromatic hydrocarbon oxidation by soil and water microorganisms and (2) determined the persistence of selected PNAs by measuring percent remaining hydrocarbon in the presence of pure and mixed microbial cultures as a function of time and by demonstrating the appearance of metabolic products Extensive removal of potentially carcinogenic PNAs can be effected even by the very dilute microbial suspensions found in natural waters Since bacterial degradation of aromatic hydrocarbons does not produce a carcinogenic species, it may be that in the natural environment microbes exert a protective effect on higher organisms by continuously removing these potentially harmful chemicals from the biosphere It is anticipated that an assessment of the biodegradability of PNAs will be of assistance to bioengineers responsible for waste management in coal conversion plantsmore » andothers concerned with abatement of PNA pollution of the environment (GRA)« less

Hydroalkylation using multimetallic zeolite catalyst

Abstract: An aromatic hydrocarbon is contacted under hydroalkylation conditions and in the presence of hydrogen with a catalyst comprising at least one ruthenium compound and at least one nickel compound supported on a calcined, acidic, rare earth-treated crystalline zeolite.

Flavorant-release resin compositions

Abstract: OF THE DISCLOSURE This invention provides alcohol flavorant-release oligomeric and polymeric derivatives corresponding to the structural formula: wherein R is selected from aliphatic, alicyclic, heterocyclic and aromatic hydrocarbon radicals; R1 and R2 are selected from hydrogen and aliphatic, alicyclic, heterocyclic and aromatic hydrocarbon radicals; and n is an integer.

Smoking tobacco compositions

Abstract: This invention provides tobacco compositions which contain a flavorant-release oligomeric and polymeric derivative corresponding to the structural formula: ##STR1## wherein R is a member selected from the group consisting of hydrogen and aliphatic, alicyclic and aromatic hydrocarbon radicals containing between 1 and about 10 carbon atoms, with the proviso that R is hydrogen when m is zero; R 1 , R 2 , R 3 and R 4 are members selected from the group consisting of hydrogen and aliphatic, alicyclic and aromatic hydrocarbon radicals; and m and n are integers.

Adsorbent for aromatic hydrocarbon mixture separation

Abstract: An adsorbent for separating para-isomers from C8 or C10 aromatic hydrocarbons, specifically, a faujasite zeolite wherein about 2.5 to 25 percent, based on the total exchangeable cation sites originally present within the faujasite zeolite, is decationized and metal ions at the residual cation sites are exchanged substantially with potassium and/or barium ions. The adsorbent is used in separating the para-isomer, which is isolated by desorbing from the adsorbent.

Manufacture of carbon fibres

Abstract: The invention relates to an improvement in a process for the production of carbon fibres (also filaments and films) from organic material consisting mainly of hydrocarbons (e.g., pitch, tars, solutions or extracts of coal). The organic material is spun or extruded to form a fibre, oxidized to stabilize it to heat treatment and subsequently carbonized. The invention comprises employing in place of, or as, the organic material consisting mainly of hydrocarbons a modified organic material formed by reacting an aromatic hydrocarbon material having at least two fused rings (which may be such an organic material consisting mainly of hydrocarbons) with a cross-linking agent, the cross-linking agent having at least two groups selected from groups that react with and substitute onto aromatic hydrocarbon rings. Suitable groups include acyl chloride, alkyl chloride, carboxylic acid anhydride, olefin, and alcoholic hydroxyl groups.

Preparation of divalent phenols

Abstract: PURPOSE: To prepare divalent phenols in high yield by the reaction of the oxidation product of m- or p-diisopropylbenzenes with hydrogen peroxide in the presence of an aromatic hydrocarbon and an acidic catalyst while removing water (as a byproduct) and the aromatic hydrocatbon as an azeotropic mixture, followed by the acid decomposition. COPYRIGHT: (C)1978,JPO&Japio

Synthesis of squaric acid

Abstract: Squaric acid is prepared by reacting hexachlorobutadiene with an excess of morpholine in the presence of an aromatic hydrocarbon solvent while maintaining the temperature between 110° C and 120° C, and then converting the resulting 1,1,3-trichloro-2,4,4-trimorpholino-butadiene to 3-morpholinotrichloro-2-cyclobuten-1-one, which in turn is hydrolyzed in the presence of strong acid to produce the desired squaric acid.

Hydroalkylation using multi metallic zeolite catalyst

Abstract: An aromatic hydrocarbon is contacted under hydroalkylation conditions and in the presence of hydrogen with a composition comprising at least one platinum compound supported on a calcined, acidic, nickel and rare earth-treated crystalline zeolite which additionally has a halide content sufficient to promote the selectivity of the composition to produce a desired cycloalkyl aromatic hydrocarbon.

Method of separation of catalytic residues derived from aluminum chloride

Abstract: The present invention relates to an improved method of separation of the mineral salts obtained from the catalyst of a Friedel-Craft reaction. The improvement to the method of alkylation of an aromatic hydrocarbon by an olefin hydrocarbon in the presence of aluminum chloride followed by neutralization of the acid alkylates by anhydrous ammonia, consists in flocculating the mineral salts obtained by said neutralization by the addition of water and separating out the salts thus flocculated.

Process for motor fuel production by olefin polymerization

Abstract: A process for the production of motor fuel by the polymerization of aliphatic C 3 and C 4 mono-olefins wherein a small amount of a liquid aromatic hydrocarbon is passed through the polymerization zone to remove polymers By-product alkylated aromatic hydrocarbons are retained in the motor fuel product as high octane components

Novel hydrogenated hydrocarbon resisn

Abstract: PURPOSE: A hydrogenated hydrocarbon resin having excellent aging resistance, consisting of units which are derived from a cyclopentadiene monomer and hydrogenated, and units which are derived from a monovinyl-substituted aromatic hydrocarbon and hydrogenated in the polymer chain in a specific proportion. COPYRIGHT: (C)1977,JPO&Japio

Process for preparing formate esters of alkyl-substituted aromatic hydroxy compounds

Abstract: Formate esters of the general formula HCOOAr wherein Ar is an aromatic hydrocarbon group containing an alkyl substituent are prepared by oxidizing alkyl aromatic aldehydes of the general formula ArCHO wherein Ar is the same as defined above with organic peroxy acids in the presence of hydrogen fluoride

Alkylation and transalkylation of aromatics - using a ZSM-21 type zeolite catalyst

Abstract: The alkylation or transalkylation of aromatic hydrocarbon feeds (opt. contg. monpolar substits.) is carried out by contacting the feed with a (trans)alkylating agent at an inlet temp. of 38-650 degrees C, an absolute presS. of 1.03-210 (pref. 1.75-56) kg/cm2, a molar ratio of aromatic hydrocarbon to (trans)alkylating agent of 1:3 to 20:1 and a WHSV of 0.5-1000 (pref. 1-20) in the presence of a zeolite of the ZSM-21 type (x-ray diffraction data given). Catalysts bssed on zeolites of the ZSM-21 type have high stability and high selectivity.

Process of production of aromatic nitriles

Abstract: Aromatic nitriles can be produced at a high conversion and at a high selectivity by filling cylindrical wire netting into a fluidized bed reactor when the aromatic nitriles are produced by subjecting a mixture of an aromatic hydrocarbon, ammonia and molecular oxygen to fluid catalytic reaction in the presence of a fluid catalyst.

Ordorless resin composition

Abstract: PURPOSE: An odorless conjugated diolefin-vinyl aromatic hydrocarbon block copolymer having good impact resistance and being used as molded products for food, which is obtained by using a combination of specific several stabilizing agents. COPYRIGHT: (C)1978,JPO&Japio

Oil soluble fungicide obtained from the reaction of a quaternary ammonium salt and an alkyl benzene sulfonic acid

Abstract: This invention provides an oil soluble fungicide comprising a compound having the general formula ##STR1## wherein R1 is a mononuclear aromatic hydrocarbon radical comprising up to 22 carbon atoms, R2 and R3, which may be the same or different, each represents an aliphatic hydrocarbon radicals comprising up to 8 carbon atoms, R4 is an aliphatic hydrocarbon radical comprising from 8 to 20 carbon atoms; R5 is an alkylbenzene radical in which the alkyl group contains from 10 to 14 carbon atoms; and X.sup.⊖ is a sulfonate radical.

Aromatic epoxy-terminated polyimides

Abstract: Aromatic epoxy-terminated aromatic polyimides and processes for their preparation are provided. The epoxidized polyimides are prepared by epoxidizing an olefinically unsaturated aromatic imide of the formula: ##STR1## WHEREIN Ar is a divalent aromatic organic radical, Ar' is a tetravalent aromatic organic radical, the four carbonyl groups being attached directly to separate carbon atoms and each pair of carbonyl groups being attached to adjacent carbon atoms in the Ar' radical, R' is a divalent aromatic hydrocarbon radical, and n is a positive integer of at least 1. Preferably, the starting aromatic imide is a styrene-terminated aromatic imide wherein n is at least 4 which is epoxidized with a per-acid.

Solvent extraction of aromatic hydrocarbons with ethylene oxide polyol adducts

Abstract: A process for the separation of aromatic hydrocarbon compounds from mixtures thereof with non-aromatic hydrocarbon compounds wherein the mixtures are contacted with an ethoxylated alkane polyol solvent having a number average molecular weight range from about 250 to about 1100 to form an extract containing the aromatics and separating the extract from the non-aromatic compounds.

Biocidal asymmetric organometallic cpds - contg two organolead and/or organotin fragments

Abstract: Asymmetric organometallic cpds of formula (I) are new: (where M and M' are Sn or Pb, R is an opt substd divalent aliphatic or aromatic hydrocarbon radical, R1-6 are opt substd aliphatic or aromatic hydrocarbon radicals, with the proviso that M can only be Sn when the S atom and the CO gp are bonded to the same C atom in R) and are biocides, esp for use in antifouling paints, they can also be used as fungicides, herbicides, insecticides and acaricides, and as biocidal additives for plasticised PVC

Polysiloxane anti-foaming agents - contg perfluoro-alkoxy groups

Abstract: Polyxiloxane anti-foaming agents, in which 20% of the siloxane units of formula (I) (in which R1 is a is 1 or 2; R2 is H or a 1-6C aliphatic gp; b is 2-12, pref. 2-6; x is 4-(m+n) /2; m is 1-3; n is 0-2, and m+n is 3) and the remaining units are of formula R3p siOq (in which R3 is H, or an aliphatic or aromatic hydrocarbon gp; p is 1,2 or 3 and q is (4-p)/2). Used in organic solvents e.G. paints, organosols, plastisols, metal degreasing, etc. and are effective in aromatic and halogenated solvents, monohydric alcohols with >7C atoms, lower ethers, etc. where other polysiloxanes are ineffective. Since only a minor proportion of units need to be of formula (I) cost is reduced.