Synthetic Phenolic Antioxidants and Their Metabolites in Sediments from the Coastal Area of Northern China: Spatial and Vertical Distributions

Synthetic phenolic antioxidants (SPAs) are widely used in foodstuffs, cosmetics, plastics, and rubber products. Little is known about their spatiotemporal distribution in the marine environment. In this study, a total of 144 surface sediments and three sediment cores were collected from the coastal areas of northern China to determine the spatial and vertical distributions of SPAs. For surface sediments, the total concentrations of five SPAs and their four metabolites (∑<sub>9</sub>SPAs) ranged from 133 to 4800 (mean: 588) ng/g dry weight (dw). The ∑<sub>9</sub>SPAs in surface sediments showed a decrease trend with the distance from the coast to the open sea. For sediment core samples, the ∑<sub>9</sub>SPAs in the inner-shelf mud (core-1 and core-3) showed a slight increase trend from the bottom to upper layers, whereas that in the central-shelf mud (core-2) did not. The principal component analysis suggests that the composition profiles of SPAs in both surface sediment and sediment core samples were similar, while the sediments close to the coast were obviously affected by the human activities. This is the first study to report the spatial and vertical distributions of SPAs and their metabolites in sediments from the coastal marine environment.