Component characteristics of polycyclic aromatic compounds in sediments of the South Mid-Atlantic Ridge

10 samples of sediments obtained from the South Mid-Atlantic Ridge were measured for the abundances and distributions of polycyclic aromatic compounds（PAHs）. The total concentrations of PAHs（∑PAHs） ranged from 2.768 to 9.826 μg/g dry sediment. The ∑PAHs was higher in sample 22V-TVG10 and sample 26V-TVG05 which were close to hydrothermal fields, with the lowest value in sample 22V-TVG14 which was farthest from hydrothermal fields, suggesting a probable hydrothermal origin of ∑PAHs of samples. Approximately nine kinds of PAHs were identified, and low molecular mass tricyclic and tetracyclic aromatic compounds were predominant in the samples. The concentrations of fluoranthene which were typical as hydrothermal alteration compounds were the highest among PAHs with dry weight between 0.913–3.157 μg/g. The phenanthrene homologue was most abundant in the samples, and the ratios between parent phenanthrene and methylphenanthrene which probably reflected the degree of hydrothermal alteration ranged from 0.097 to 1.602. The sample 22V-TVG10 possessing a maximum ratio value showed the intense influence of the hydrothermal alteration on this sample, which might further imply that PAHs in sediments were mainly derived from the hydrothermal alteration.

Monitoring of Potential carcinogenic polycyclic aromatic compounds in the emission from coal combustion

A comprehensive summary for the study on the monitoring of potential carcinogenicpolycyclic aromatic compounds (PACs) in the emission of coal combustion is presented in this pa-per. Some PACs in the stack gases of coal-fired boiler have been determined with a procedure whichconsists of isokinetic stack sampling, extraction, preseparation and some instrumental analysis stepssuch as gas chromatographylmass spectrometry (GC/MS), high performance liquid chromatographyfHPLC), room temperature phosphorimetry (RTP) and synchronous fluorescence spectroscopy (SFS)and so on. The results indicate that the air pollution of PACs in China are related closely to thecoal combustion.

Characterizations of organic compounds in diesel exhaust particulates

To characterize how the speed and load of a medium-duty diesel engine affected the organic compounds in diesel particle matter（PM） below 1 μm, four driving conditions were examined. At all four driving conditions, concentration of identifiable organic compounds in PM ultrafine（34–94 nm） and accumulation（94–1000 nm） modes ranged from 2.9 to 5.7 μg/m3 and 9.5 to 16.4 μg/m3, respectively. As a function of driving conditions, the non-oxygencontaining organics exhibited a reversed concentration trend to the oxygen-containing organics. The identified organic compounds were classified into eleven classes： alkanes,alkenes, alkynes, aromatic hydrocarbons, carboxylic acids, esters, ketones, alcohols, ethers,nitrogen-containing compounds, and sulfur-containing compounds. At all driving conditions,alkane class consistently showed the highest concentration（8.3 to 18.0 μg/m3） followed by carboxylic acid, esters, ketones and alcohols. Twelve polycyclic aromatic hydrocarbons（PAHs）were identified with a total concentration ranging from 37.9 to 174.8 ng/m3. In addition, nine nitrogen-containing polycyclic aromatic compounds（NPACs） were identified with a total concentration ranging from 7.0 to 10.3 ng/m3. The most abundant PAH（phenanthrene）and NPACs（7,8-benzoquinoline and 3-nitrophenanthrene） comprise a similar molecular（3 aromatic-ring） structure under the highest engine speed and engine load.

Two Dimensional Triptycene End-Capping and Its Influence on the Self-Assembly of Quinoxalinophenanthrophenazines

In this report we investigated two-dimensionally triptycene end-capped QPPs in terms of their solution and solid-state behavior.For this purpose,a triphenylene based ortho-diamine decorated with two triptycenyl units as well as a phenylene diamine with two non-annulated triptycene units have been synthesized.Sequences of condensation reactions with a pyrene-based tetraketone and ortho-diamines yielded a series of QPPs and UV/Vis investigations of the corresponding compounds led to the conclusion,that the QPPs form dimers in solution,which was further supported by MALDI-TIMS-TOF-MS.Single-crystal X-ray analysis of the triply and quadruply triptycene end-capped QPPs furthermore showed shortπ-π-distances of 3.3-3.4?and a perfect shape match during the dimerization of the triply triptycenyl end-capped QPP making it possible synthon for crystal engineering.