Alternative fuels are being considered for civilian and military uses. One of these is S-8, a replacement jet fuel synthesized using the Fischer-Tropsch process, which contains no aromatic compounds and is mainly composed of straight and branched alkanes. Metabolites of S-8 fuel in laboratory animals have not been identified. The goal of this study was to identify metabolic products from exposure to aerosolized S-8 and a designed straight-chain alkane/polyaromatic mixture (decane, undecane, dodecane, tridecane, tetradecane, pentadecane, naphthalene, and 2-methylnaphthalene) in male Fischer 344 rats. Collected blood and tissue samples were analyzed for 70 straight and branched alcohols and ketones ranging from 7 to 15 carbons. No fuel metabolites were observed in the blood, lungs, brain, and fat following S-8 exposure. Metabolites were detected in the liver, urine, and feces. Most of the metabolites were 2- and 3-position alcohols and ketones of prominent hydrocarbons with very few 1- or 4-position metabolites. Following exposure to the alkane mixture, metabolites were observed in the blood, liver, and lungs. Interestingly, heavy metabolites (3-tridecanone, 2-tridecanol, and 2-tetradecanol) were observed only in the lung tissues possibly indicating that metabolism occurred in the lungs. With the exception of these heavy metabolites, the metabolic profiles observed in this study are consistent with previous studies reporting on the metabolism of individual alkanes. Further work is needed to determine the potential metabolic interactions of parent, primary, and secondary metabolites and identify more polar metabolites. Some metabolites may have potential use as biomarkers of exposure to fuels.
Jet propellant 8 (JP-8) jet fuel is a complex mixture of aromatic and aliphatic hydrocarbons. The aim of this study was to determine in vitro metabolic rate constants for semivolatile n-alkanes, nonane (C9), decane (C10), and tetradecane (C14), by rat liver microsomal oxidation. The metabolism was assessed by measuring the disappearance of parent compound by gas chromatography. Various concentrations of n-alkanes were incubated with liver microsomes from adult male F-344 rats. Nonlinear kinetic constants for nonane and decane were V(max) (nmol/mg protein/min) = 7.26 +/- 0.20 and 2.80 +/- 0.35, respectively, and K(M) (micro M) = 294.83 +/- 68.67 and 398.70 +/- 42.70, respectively. Metabolic capacity as assessed by intrinsic clearance (V(max)/K(M)) was approximately four-fold higher for nonane (0.03 +/- 0.005) than for decane (0.007 +/- 0.001). There was no appreciable metabolism of tetradecane even with higher microsomal protein concentration and longer incubation time. These results show a negative correlation between metabolic clearance and chain length of n-alkanes. These metabolic rate constants will be used to update existing physiologically based pharmacokinetic (PBPK) models for nonane and decane as part of developing a PBPK model for JP-8.
Candida lipolytica ATCC 8661 was grown in a mineral salts hydrocarbon medium. n-Tetradecane was one of the substrates used. ... Analyses of fluids from cultures grown on n-alkanes indicated a predominance of fatty acids and alcohols of the same chain length as the substrate. In addition, numerous other fatty acids and alcohols were present. Analyses of saponifiable and nonsaponifiable material obtained from the cells revealed essentially the same products. The presence of primary and secondary alcohols, as well as fatty acids, of the same chain length as the n-alkane substrate suggested that attack on both the methyl and alpha-methylene group was occurring.
IDENTIFICATION AND USE: N-Tetradecane is a colorless liquid. It is used in organic synthesis, also as solvent standardized hydrocarbon, and as distillation chaser. HUMAN EXPOSURE AND TOXICITY: During industrial use, tetradecane may be harmful by inhalation, ingestion, or skin absorption. ANIMAL STUDIES: Tetradecane administered topically in a rabbit model caused a marked hyperplasia of sebaseous glands, epidermis, and follicular epithelium. Intravenous injection in mice was lethal at 5800 mg/kg. Animals presented altered sleep time, including change in righting reflex. Tetradecane, when aspired into the lungs, is an asphyxiant similar to the C6-C10 alkanes. These alkanes cause death more slowly and can cause chemical pneumonitis. Tetradecane was a carcinogen and tumor promoter in two-stage experiments of benzo[a]pyrene carcinogenicity in mice. Tetradecane enhances the mitogenic response of murine spleen lymphocytes to the lectin phytohemagglutinin.
... The present study is an ongoing approach to assess the dose-related percutaneous absorption of a number of aliphatic and aromatic hydrocarbons. The first treatment (1X) was comprised of mixtures containing undecane (4.1%), dodecane (4.7%), tridecane (4.4%), tetradecane (3%), pentadecane (1.6%), naphthalene (1.1%), and dimethyl naphthalene (1.3% of jet fuels) in hexadecane solvent using porcine skin flow through diffusion cell. Other treatments (n = 4 cells) were 2X and 5X concentrations. Perfusate samples were analyzed with gas chromatography-flame ionization detector (GC-FID) using head space solid phase micro-extraction fiber technique. We have standardized the assay to have a good linear correlation for all the tested components in media standards. Absorption parameters including diffusivity, permeability, steady state flux, and percent dose absorbed were estimated for all the tested hydrocarbons. This approach provides a baseline to access component interactions among themselves and with the diluent (solvents). A quantitative structure permeability relationship (QSPR) model was derived to predict the permeability of unknown jet fuel hydrocarbons in this solvent system by using their physicochemical parameters. Our findings suggested a dose related increase in absorption for naphthalene and dimethyl naphthalene (DMN).
来源:Hazardous Substances Data Bank (HSDB)
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十四烷增强了小鼠脾淋巴细胞对植物血凝素植物凝集素的增殖反应。
Tetradecane enhances the mitogenic response of murine spleen lymphocytes to the lectin phytohemagglutinin.
Linear alkanes of specific chain length enhanced differentially the mitogenic response of murine spleen lymphocytes to the lectin phytohemagglutinin. A biphasic structure-function relationship was found, with maximum comitogenic activity occurring for tetradecane.
/SRP:/ Immediate first aid: Ensure that adequate decontamination has been carried out. If patient is not breathing, start artificial respiration, preferably with a demand-valve resuscitator, bag-valve-mask device, or pocket mask, as trained. Perform CPR as necessary. Immediately flush contaminated eyes with gently flowing water. Do not induce vomiting. If vomiting occurs, lean patient forward or place on left side (head-down position, if possible) to maintain an open airway and prevent aspiration. Keep patient quiet and maintain normal body temperature. Obtain medical attention. /Aliphatic hydrocarbons and related compounds/
Dermal penetration and absorption of jet fuels in general, and JP-8 in particular, is not well understood, even though government and industry, worldwide, use over 4.5 billion gallons of JP-8 per year. Exposures to JP-8 can occur from vapor, liquid, or aerosol. Inhalation and dermal exposure are the most prevalent routes. JP-8 may cause irritation during repeated or prolonged exposures, but it is unknown whether systemic toxicity can occur from dermal penetration of fuels. The purpose of this investigation was to measure the penetration and absorption of JP-8 and its major constituents with rat skin, so that the potential for effects with human exposures can be assessed. We used static diffusion cells to measure both the flux of JP-8 and components across the skin and the kinetics of absorption into the skin. Total flux of the hydrocarbon components was 20.3 micrograms/sq cm/hr. Thirteen individual components of JP-8 penetrated into the receptor solution. The fluxes ranged from a high of 51.5 micrograms/sq cm/hr (an additive, diethylene glycol monomethyl ether) to a low of 0.334 micrograms/sq cm/hr (tridecane). Aromatic components penetrated most rapidly. Six components (all aliphatic) were identified in the skin. Concentrations absorbed into the skin at 3.5 hr ranged from 0.055 micrograms per gram skin (tetradecane) to 0.266 micrograms per gram skin (undecane). These results suggest: (1) that JP-8 penetration will not cause systemic toxicity because of low fluxes of all the components; and (2) the absorption of aliphatic components into the skin may be a cause of skin irritation.
JP-8 has been associated with toxicity in animal models and humans. There is a great potential for human exposure to JP-8. Quantitation of percutaneous absorption of JP-8 is necessary for assessment of health hazards involved in its occupational exposure. In this study, we selected three aliphatic (dodecane, tridecane, and tetradecane) and two aromatic (naphthalene and 2-methylnaphthalene) chemicals, which are major components of JP-8. We investigated the changes in skin lipid and protein biophysics, and macroscopic barrier perturbation from dermal exposure of the above five chemicals. Fourier transform infrared (FTIR) spectroscopy was employed to investigate the biophysical changes in stratum corneum (SC) lipid and protein. FTIR results showed that all of the above five components of JP-8 significantly (P<0.05) extracted SC lipid and protein. Macroscopic barrier perturbation was determined by measuring the rate of transepidermal water loss (TEWL). All of the five JP-8 components studied, caused significant (P<0.05) increase in TEWL in comparison to control. We quantified the amount of chemicals absorbed assuming 0.25 sq m body surface area exposed for 8 hr. Our findings suggest that tridecane exhibits greater permeability through skin among aliphatic and naphthalene among aromatic JP-8 components. Amount of chemicals absorbed suggests that tridecane, naphthalene and its methyl derivatives should be monitored for their possible systemic toxicity.
... JP-8 is a complex mixture containing >200, mostly toxic, aliphatic and aromatic hydrocarbon compounds of which tetradecane and naphthalene were chosen as two representative chemical markers for computer simulations. Thus, transport and deposition of naphthalene and tetradecane vapors have been simulated in models of the human respiratory system. The inspiratory deposition data were analyzed in terms of regional deposition fractions (DFs) and deposition enhancement factors (DEF). The vapor depositions are affected by vapor properties (e.g. diffusivity), airway geometric features, breathing patterns, inspiratory flow rates, as well as airway-wall absorption parameter. Specifically, the respiratory uptake of vapors is greatly influenced by the degree of airway-wall absorption. For example, being an almost insoluble species in the mucus layer, the deposition of tetradecane vapor is nearly zero in the extrathoracic and tracheobronchial (TB) airways, that is, the DF is <1%. The remaining vapors may penetrate further and deposit in the alveolar airways. The DF of tetradecane vapors during inhalation in the alveolar region can range from 7% to 24%, depending on breathing waveform, inhalation rate, and thickness of the mucus layer. In contrast, naphthalene vapor almost completely deposits in the extrathoracic and TB airways and hardly moves downstream and deposits in the respiratory zone. The DFs of naphthalene vapor in the extrathoracic airways from nasal/oral to trachea under normal breathing conditions (Q = 15-60 L/min) are about 12-34%, although they are about 66-87% in the TB airways. In addition, the variation of breathing routes (say, from nasal breathing to oral breathing) may influence the vapor deposition in the regions of nasal and oral cavities, nasopharynx and oropharynx, but hardly affects the deposition at and beyond the larynx. The different deposition patterns of naphthalene and tetradecane vapors in the human respiratory system may indicate different toxic and hence health effects of these toxic jet-fuel components.
Rat tissue:air and blood:air partition coefficients (PCs) for octane, nonane, decane, undecane, and dodecane (n-C8 to n-C12 n-alkanes) were determined by vial equilibration. The blood:air PC values for n-C8 to n-C12 were 3.1, 5.8, 8.1, 20.4, and 24.6, respectively. The lipid solubility of n-alkanes increases with carbon length, suggesting that lipid solubility is an important determinant in describing n-alkane blood:air PC values. The muscle:blood, liver: blood, brain:blood, and fat:blood PC values were octane (1.0, 1.9, 1.4, and 247), nonane (0.8, 1.9, 3.8, and 274), decane (0.9, 2.0, 4.8, and 328), undecane (0.7, 1.5, 1.7, and 529), and dodecane (1.2, 1.9, 19.8, and 671), respectively. The tissue:blood PC values were greatest in fat and the least in muscle. The brain:air PC value for undecane was inconsistent with other n-alkane values. Using the measured partition coefficient values of these n-alkanes, linear regression was used to predict tissue (except brain) and blood:air partition coefficient values for larger n-alkanes, tridecane, tetradecane, pentadecane, hexadecane, and heptadecane (n-C13 to n-C17). Good agreement between measured and predicted tissue:air and blood:air partition coefficient values for n-C8 to n-Cl2 offer confidence in the partition coefficient predictions for longer chain n-alkanes.
1.周国泰，化学危险品安全技术全书，化学工业出版社，1997 2.国家环保局有毒化学品管理办公室、北京化工研究院合编，化学品毒性法规环境数据手册，中国环境科学出版社.1992 3.Canadian Centre for Occupational Health and Safety,CHEMINFO Database.1998 4.Canadian Centre for Occupational Health and Safety, RTECS Database, 1989
Catalytic oxidation of heavy hydrocarbons over Pt/Al2O3. Oxidation of C10+ solid hydrocarbons representative of soluble organic fraction of Diesel soots
摘要：
Oxidation of 20 hydrocarbons (from C10 to C42) representative of soluble organic fraction of Diesel soots were investigated by mixing the hydrocarbon (solid at ambient temperature) with a 0.55 wt%Pt/Al2O3 catalyst (Pt particle size below 1.2 nm). Oxidation rates were characterized by the temperature of half-conversion (T-50) and by the quantity of oxygen consumed during the reaction, which allows to determine the amount of the solid hydrocarbon (initially 100 mg of a mixture of 0.133 mmol HC with 2 g of catalyst) actually oxidized during heating in 1%O-2/He.A preliminary study carried out with two selected hydrocarbons showed that turnover frequencies (TOF) are little dependent on the Pt loading. The hydrocarbons should be vaporized before them to react with the Pt catalyst. Ideally, temperatures of light-off and of vaporization should coincide for the optimal transformation into CO2. The molecular structure of the hydrocarbon (number of aromatic rings, MC ratio, condensed structures, etc.) is a key-parameter for both oxidation and volatility, which explains why a good correlation was observed between T-50 and boiling temperatures T-b. A comparison with light-off tests performed in a stream of gaseous hydrocarbon (vaporized upstream the catalyst) showed that oxidation rates depend on the same structural parameters, except when the hydrocarbon is too volatile (i.e. naphthalene) or, on the contrary, not sufficiently volatile (i.e. n-alkanes in C20-C34). In the first case, a large HC fraction is desorbed without being oxidized while in the second case, oxidation rate is limited by the vaporization. (C) 2014 Elsevier B.V. All rights reserved.
Facile Barton−McCombie Deoxygenation of Alcohols with Tetrabutylammonium Peroxydisulfate and Formate Ion
作者：Hee Sock Park、Hee Yoon Lee、Yong Hae Kim
DOI：10.1021/ol050886h
日期：2005.7.1
[reaction: see text]. A new method for efficient radical deoxygenation of alcohols is described for preparing bulk chemicals avoiding scale-up problems. Treatment of various thiocarbonyl derivatives with (Bu(4)N)(2)S(2)O(8) and HCO(2)Na in DMF afforded the corresponding deoxygenated products in excellent yields. The deoxygenation appears to be initiated by the transfer of a single electron to thiocarbonyl
Thiol-Catalyzed Radical Decyanation of Aliphatic Nitriles with Sodium Borohydride
作者：Takuji Kawamoto、Kyohei Oritani、Dennis P. Curran、Akio Kamimura
DOI：10.1021/acs.orglett.8b00626
日期：2018.4.6
Radical decyanation of aliphaticnitriles was achieved in the presence of NaBH4 and a thiol. The reaction proceeds via a radical mechanism involving borane radical anion addition to nitrile to form an iminyl radical, which undergoes carbon–carbon cleavage. Reductive radical addition to acrylonitrile is followed by decyanation to give a two-carbon homologated product in a net radical ethylation reaction
Bifunctional compounds from reaction of alkoxy hydroperoxides with metal salts
作者：G. Cardinale、J.A.M. Laan、D. Van Der Steen、J.P. Ward
DOI：10.1016/s0040-4020(01)91447-4
日期：1985.1
with ferrous sulfate. C-C bond scission and radical formation was followed by dimerization of the radicals formed. Ozonides reacted similarly. Acyclic and cyclic olefins, including a cyclic enol ether, gave rise to a range of α,ω-disubstituted products in modest yields. By using ferric chloride, ω-chloro esters were obtained from the alkoxy hydroperoxides derived from olefinic esters.
Processes are disclosed for preparation of N-aryl-S,S-dihydrocarbylsulfilimines by reaction of phenylisocyanate compounds with hydrocarbyl sulfoxides. The sulfilimines can be rearranged to ortho-thioalkylene anilines and the reactions can be employed in a route for converting nitrobenzene compounds to ortho-thioalkylene anilines, which are useful intermediates for preparation of herbicidal compounds.
Transition-metal-catalyzed cross-coupling reactions between naturally abundant sp3-hybridized carbon centers facilitate access to diverse molecules with complex three-dimensional structures. Organometallic compounds are among one of the most powerful reagents that are broadly used in carbon–carbon bondformations. Although sp2-hybridized organometallic compounds are widely employed in cross-couplings, sp3-hybridized
