An assessment of human influences on sources of polycyclic aromatic hydrocarbons in the estuarine and coastal sediments of China.

Sediments collected from the coastal area of China, embracing west coast of Bohai Sea, south coast of Shandong Peninsula, and the Changjiang estuary (listed in order of decreasing north latitude), were analyzed for polycyclic aromatic hydrocarbons (PAHs). ∑PAH (Sixteen US EPA priority PAHs) were 2.7-350.9ng/g. Petroleum residue was the major contributor of PAHs in the coastal sediments of China due to oil leakage from ships and offshore oil fields. The contribution of vehicular emissions in coast of North China was significantly lower than that in the Changjiang Estuary, and the reverse was true for coal combustion. PAH concentrations in the sediment core of the Changjiang estuary steadily increased upward and the variation was primarily due to economic development and severe floods. The impact on PAHs by vehicular emissions (37.2%) and petrogenic sources (45.8%) overwhelmed combustion sources (17.0%).

Rapid screening and identification of the antioxidants in Hippocampus japonicus Kaup by HPLC-ESI-TOF/MS and on-line ABTS free radical scavenging assay.

In this paper, a method based on HPLC coupled with ESI-TOF/MS and on-line to a stable free radical scavenging detection system has been developed to rapidly screen and identify the major antioxidants in the water extract of Hippocampus japonicus Kaup, a kind of marine medicinal organism. The developed on-line stable free radical scavenging detection method of water extract from H. japonicus Kaup revealed the presence of three radical scavenging compounds, which were simultaneously identified as hypoxanthine, phenylalanine and tryptophane by high-resolution TOF-MS. To the best of our knowledge, it is original to demonstrate the rapid and successful use of HPLC-ESI-TOF/MS and on-line 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonate) diammonium salt free radical scavenging assay to directly and simultaneously screen and identify the antioxidants in the water extracts of H. japonicus Kaup without any purification. The present method provides a useful improvement on the reducing of workload and a powerful tool for rapid screening and identification of free radical scavenging compounds in complex natural products.