Hydrocarbons polycyclic aliphatic

Polyamides, 809-810 Polyamines, 870 Polychlorinated biphenyls, 938 Polycyclic hydrocarbons aliphatic, 114—116 aromatic, 408—409, 474—475 and cancer, 409 Polyesters, 809 Polyethers, 622-625... 

Halogenated chemicals Polycyclic aromatic hydrocarbons Aliphatics Substituted benzenes Halogenated aliphatics Dioxins and furans... 

Pyriki, C. Polycyclische und aliphatische Kohlenwas-serstoffe des Tabakrauches [The polycyclic and aliphatic hydrocarbons of tobacco smoke] German Chem. Soc., Ann. Mtg., Leipzig DDR (1962) Die Nahrung 7 (1963) 439 8. 

Polycyclic hydrocarbons are extremely reactive with ozone. For example, naphthalene reacted with ozone at a rate about 1500 times faster than benzene (Hoigne and Bader, 1983b), and higher polycyclic hydrocarbons such as phenanthrene, pyrene, and benzo[a]pyrene were also extremely reactive (Butkovic et al., 1983). The experiments of Hoigne and Bader also indicate that the rate constants for reaction of ozone with aromatic hydrocarbons in water were about 100 times greater than in nonpolar solvents such as CCI4. However, aliphatic compounds did not show such a profound solvent effect. 

Pertraction is especially snitable for the removal of hydro-phobic organic componnds, snch as aromatic and aliphatic organics, chlorinated solvents (e.g., carbon tetrachloride, chloroform, tetrachloroethene, or trichloroethene), polychlorinated biphenyls (PCBs), di- and trichlorobenzene, pesticides, and higher polycyclic hydrocarbons [103,104]. 

Unsaturated cyclic hydrocarbons, aromatic hydrocarbons and their derivatives, and polycyclic hydrocarbons give a very sensitive reaction with sulfuric acid and formaldehyde, in which deeply colored resinous substances are formed. In this manner as little as 0.1% of benzene in solvent mixtures can be detected. Saturated hydrocarbons, unsaturated aliphatic hydrocarbons, and cyclic saturated hydrocarbons do not give this reaction. 

Aromatic hydrocarbons with aliphatic side chains, e.g., toluene, do not form mercapturic acids at all. Instead, the side chain is oxidized to a carboxyl group. Similarly, alcohols, aldehydes, phenols, etc., are not converted to mercapturic acids. On polycyclic hydrocarbons, a methyl group may be slowly attacked. 7-Methyh and 12-methylbenz(a)anthra cene form traces of mercapturic acids but 7,l2-diraethylbenz a)anthracene forms none. 

Zebiihr et al. (29) developed an automated system for determining PAHs, PCBs and PCDD/Fs by using an aminopropyl silica column coupled to a porous graphitic carbon column. This method gives five fractions, i.e. aliphatic and monoaromatic hydrocarbons, polycyclic aromatic hydrocarbons, PCBs with two or more ortho-chlorines, mono-ort/io PCBs, and non-ortho PCBs and PCDD/Fs. This method employed five switching valves and was successfully used with extracts of sediments, biological samples and electrostatic filter precipitates. 

Alicyclic Hydrocarbons. These refer to cyclic analogues of aliphatic hydrocarbons and are named accordingly, using the piefix cyclo-." Their properties are similar to their open-chain aliphatic counterparts. Alicyclic hydrocarbons are subdivided into monocyclic (cycloalkanes, cycloalkenes, cycloalkynes, cycloalkadienes, etc.) and polycyclic aliphatic compounds. Monocyclic aliphatic structures having more than 30 carbon atoms in the ring are known, but those containing 5 or 6 carbon atoms are more commonly found in nature [47, p. 28]. 

Polycyclic aliphatic hydrocarbons. These may contain two or more rings that share two or more carbon atoms. An example of a fused-ring system is... 

The aliphatic rings may be saturated or partially unsaturated. Spiro hydrocarbons also belong to the polycyclic group. More examples may be found in the CRC Handbook [63]. 

Although these issues have already been briefly noted, they deserve a few additional comments. For freely water-soluble substrates that have low volatility, there are few difficulties in carrying out the appropriate experiments described above. There is, however, increasing interest in xenobiotics such as polycyclic aromatic hydrocarbons (PAHs) and highly chlorinated compounds including, for example, PCBs, which have only low water solubility. In addition, attention has been focused on volatile chlorinated aliphatic compounds such as the chloroethenes, dichloromethane, and carbon tetrachloride. All of these substrates present experimental difficulties of greater or lesser severity. 

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