Electrochromatography is utilized to separate a mixture of 16 different polycyclic aromatic hydrocarbons (PAHs). Fused-silica capillary columns ranging in size from 50 to 150 pm i.d. were packed (20-40-cm sections) with 3-pm octadecylsilica particles. A potential of 15-30 kV is applied across the 30-50-cm total length capillary column to generate electroosmotic flow that carries the PAHs throug...

G. Clar 6n Rule versus Hückel 4n + 2 Rule 3464 H. Hydrocarbons versus Heteroatomic Systems 3465 IV. Hidden Treasures of Kekulé Valence Structures 3466 A. Conjugated Circuits 3467 B. Innate Degree of Freedom 3470 C. Clar Structures 3472 V. Graph Theoretical Approach to Chemical Structure 3473 A. Metric 3473 B. Chemical Graphs 3473 C. Isospectral Graphs 3473 D. Embedded Graphs 3475 E. Partial Ord...

The concept of numerical Kekulé structures is used for coding and ordering geometrical (standard) Kekulé structures of several classes of polycyclic conjugated molecules: catacondensed, pericondensed, and fully arenoid benzenoid hydrocarbons, thioarenoids, and [N]phenylenes. It is pointed out that the numerical Kekulé structures can be obtained for any class of polycyclic conjugated systems tha...

A symposium on "Polycyclic Aromatic Hydrocarbons (PAHs) in Carcinogenesis" was presented at the third International Congress of Pathophysiology held in Lathi, Finland, 28 June-3 July 1998. The congress was also sponsored by the International Union of Biological Sciences and the International Society of Free Radical Research. Institutional support for the symposium included the Electric Power Re...

Two-dimensional arrays consisting of strongly subspectral molecular graphs and formula periodic tables for polycyclic aromatic hydrocarbons are briefly reviewed. New two-dimensional arrays for free-radical benzenoid hydrocarbons are presented with general analytical expressions for counting their number of resonance structures (SC). The structural origin of the coefficients to these analytical ...

Co-oxidation is a little understood means of microbial degradation of petroleum hydrocarbons. In co-oxidation, microbes growing on one compound, the growth substrate, are able to oxidize a second · compound, the cosubstrate. This project examines the role of co-oxidation in the degradation of polycyclic aromatic hydrocarbons (PAR's), one of the most recalcitrant petroleum compounds now found in...

Attempts to induce liver tumors with the car cinogenic polycyclic aromatic hydrocarbons have generally failed (9). However, certain of these hydrocarbons have a marked effect on hepatic carcinogenesis induced by other agents. Thus, Richardson et al. (32) observed that 3-methylcholanthrene1 (MC), administered at a low level to rats also receiving the strong hepatocarcinogen 3'-methyl-4-dimethyla...

background: polycyclic aromatic hydrocarbons (pahs) such as naphthalene (nap) are organic pollutants that have spread widely in littoral marine ecosystems. we aimed to study the effect of acute and prolonged exposure to naphthalene (nap) on plasma cortisol and thyroid levels in mature and immature liza klunzingeri mulet. methods: in acute stress experiment, the treatment group received 2μl g-1 ...

polycyclic aromatic hydrocarbons (pahs) in the priority controlling list of us epa weresystematically evaluated in surface sediments in dianchi lake and its estuaries. total pah concentrations(σpahs) varied from 210 to 11,070 ng/g dry weight (d.w.) in dianchi lake, and from 230 to 12,271 ng/g d.w.in the estuaries. σpahs in sediments from caohai section were higher than those from waihai section...

the expansion of a microbial bank for the degradation of polycyclic aromatic hydrocarbons (pahs) is crucial for removal of these persistent pollutants. in this study, five gram-negative, aerobic, non-fermentative bacterial strains (iii-r3, iv-p11, iv-p13, iv-r13, and v-p18) were isolated from the activated sludge of a petrochemical wastewater treatment plant using enrichment pro­ tocol based on...