Heterocyclic hydrocarbons

Yamanchi T, T Handa (1987) Characterization of aza heterocyclic hydrocarbons in urban atmospheric particulate matter. Environ Sci Technol 21 1177-1181. 

Yamauchi, T., and T. Handa, Characterization of Aza Heterocyclic Hydrocarbons in Urban Atmospheric Particulate Matter, Environ. Sci. Technol., 21, 1177-1181 (1987). 

In the 1960s, the Emanuel Institute of Bioehemical Physics, Russian Academy of Sciences, initiated studies in the new field - chemistry and biology of antioxidants. The scientists of the Institute had to solve an important task - to find out whether the biological activity of antioxidants as inhibitors of radical reactions depends on their properties. For this purpose, nontoxic different-structure antioxidants were synthesized derivatives of hindered phenols and heterocyclic hydrocarbon hydroxy compoimds [12, 13]. The existence of homologous arrays of antioxidant derivatives made it possible to determine the structure-activity dependence and select the most efficient and least toxic compoimds. 

Polycyclic aromatic and heterocyclic hydrocarbons KMn04 P-Propiolactone Protease inhibitors NaNHj... 

Hydrocarbons. The hydrocarbons, as the name implies, are compounds containing carbon and hydrogen. If the carbon atoms lie in the same plane they are known as open-chain, or aliphatic hydrocarbons. If the carbon atoms form a ring structure they are known as cyclic hydrocarbons. The cyclic hydrocarbons are further differentiated into benzene benzenoid, or aromatic) and alicydic hydrocarbons. If there is another element present in the ring besides carbon, they are known as heterocyclic hydrocarbons. 

Dioxins are a family of heterocyclic hydrocarbons, mostly poisonous chemical by-products of the manufacture of certain herbicides and bactericides. The most toxic are polychlorinated dibenzo-p-dioxins (CDDs) and dibenzo-furans (CDFs, also called dioxins) [514,515]. Amongst the most dangerous are the isomers of the 2,3,7,8-tetrachlorodibenzo-para-dioxin (TCDD) and 2,3,7,8-tetrachlorodibenzo-furan (TCDF). The former occurs in small amounts in some herbicides and defoliants, including the so-called Agent Orange (a highly toxic herbicide sprayed as a defoliant in chemical warfare) [466]. 

The extraction of aromatic hydrocarbons (Fig. 5.5) from crude oil uses two sorbents in series, first a cyanopropyl column attached to a second silica column. In this procedure, aromatic hydrocarbons are sorbed on both the cyanopropyl sorbent and on the silica sorbent. The heteroatom hydrocarbons (containing nitrogen, oxygen, and sulfur) are trapped on the cyanopropyl sorbent and eluted as a separate fraction from the silica column. Because the major interaction of aromatic heterocyclic hydrocarbons is through hydrogen bonding to the surface of the sorbent, the cyanopropyl sorbent is easier to elute than a silica sorbent alone. For this reason, the cyanopropyl column is used before the silica column. The separation of hydrocarbons from crude oil is an example of normal-phase chromatography that has been performed for many years on silica gel prior to the introduction of SPE. 

The term dioxin refers to a class of heterocyclic hydrocarbons compounds used in various industrial processes, such as paper manufacture and waste incineration. They readily pass into and accumulate in living systems. Animal experiments have demonstrated that these chemicals can produce mutations and fetal malformations. They have also been implicated as human carcinogens. 

According to Meerwein and others,323,516 use of boron trifluoride may be valuable, since it forms well-defined molecular compounds with simple aliphatic carboxylic acids for example, aromatic and heterocyclic hydrocarbons and aryl ethers can be acetylated smoothly and in good yield by acetic anhydride and boron trifluoride.323 The preparation of boron trifluoride has been described by Krause and Nitsche and by Booth and Willson.517... 

Brown, E.V., I. Ahmad, and A.J. Poole Investigations of the identification and quantitative estimation of V-heterocyclic hydrocarbons in tobacco smoke Proc. University of Kentucky Tobacco Hlth. Workshop 2 (1970) 124. 

Depending on conditions, in the course of the moderate combustion, organic acids may also be formed (at lower temperatures) in a thermal regime corresponding to 523-573 K, heterocyclic hydrocarbons are formed. The production of alcohols is sometimes also observed, particularly in fuel-enriched mixtures. Carbon monoxide, carbon dioxide and water are the main final products. 

Asphalt fumes (CAS 8052-42-4) Vapors and fumes irritating to eyes, skin, and respiratory tract. Skin contact can produce hyperpigmentation, dermatitis, or photosensitization. Some constituents are carcinogenic in test animals. 0.5 mg/m Smoke with an acrid odor. Asphalt Is a complex mixture of paraffinic, aromatic, and heterocyclic hydrocarbons formed by the evaporatioh of lighter hydrocarbons from petroleum and the partial oxidation of fhe residue. 

Various (Steroids, sterols, terpenoids, alicyclic and heterocyclic hydrocarbons, alkaloids, antibiotics, aromatic hydrocarbons, aliphatic hydrocarbons, amino acids and peptides, carbohydrates)... 

There are many other methods using CPE for the determination of either heterocyclic hydrocarbons, as, e.g., multi-walled carbon nanotube paste electrode used for AdS SWV determination of insecticide cyromazine, or methods for the determination of aromatic hydrocarbons containing compounds, e.g., reference (140) but they are based on reactions of nonaromatic components (as thiocholine) which is out of the scope of this chapter. 

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