Fate of Polycyclic Aromatic Hydrocarbons in Seawater from the Western Pacific to the Southern Ocean (17.5°N to 69.2°S) and Their Inventories on the Antarctic Shelf

Semivolatile organic compounds such as polycyclic aromatic hydrocarbons (PAHs) have the potential to reach pristine environments through long-range transport. To investigate the long-range transport of the PAHs and their fate in Antarctic seawater, dissolved PAHs in the surface waters from the western Pacific to the Southern Ocean (17.5°N to 69.2°S), as well as down to 3500 m PAH profiles in Prydz Bay and the adjacent Southern Ocean, were observed during the 27th Chinese National Antarctic Research Expedition in 2010. The concentrations of Σ₉PAH in the surface seawater ranged from not detected (ND) to 21 ng L^–1, with a mean of 4.3 ng L^–1; and three-ring PAHs were the most abundant compounds. Samples close to the Australian mainland displayed the highest levels across the cruise. PAHs originated mainly from pyrogenic sources, such as grass, wood, and coal combustion. Vertical profiles of PAHs in Prydz Bay showed a maximum at a depth of 50 m and less variance with depth. In general, we inferred that the water masses as well as the phytoplankton were possible influencing factors on PAH surface-enrichment depth-depletion distribution. Inventory estimation highlighted the contribution of intermediate and deep seawater on storing PAHs in seawater from Prydz Bay, and suggested that climate change rarely shows the rapid release of the PAHs currently stored in the major reservoirs (intermediate and deep seawater)

Data_Sheet_1_Discovery of the Consistently Well-Performed Analysis Chain for SWATH-MS Based Pharmacoproteomic Quantification.PDF

<p>Sequential windowed acquisition of all theoretical fragment ion mass spectra (SWATH-MS) has emerged as one of the most popular techniques for label-free proteome quantification in current pharmacoproteomic research. It provides more comprehensive detection and more accurate quantitation of proteins comparing with the traditional techniques. The performance of SWATH-MS is highly susceptible to the selection of processing method. Till now, ≥27 methods (transformation, normalization, and missing-value imputation) are sequentially applied to construct numerous analysis chains for SWATH-MS, but it is still not clear which analysis chain gives the optimal quantification performance. Herein, the performances of 560 analysis chains for quantifying pharmacoproteomic data were comprehensively assessed. Firstly, the most complete set of the publicly available SWATH-MS based pharmacoproteomic data were collected by comprehensive literature review. Secondly, substantial variations among the performances of various analysis chains were observed, and the consistently well-performed analysis chains (CWPACs) across various datasets were for the first time generalized. Finally, the log and power transformations sequentially followed by the total ion current normalization were discovered as one of the best performed analysis chains for the quantification of SWATH-MS based pharmacoproteomic data. In sum, the CWPACs identified here provided important guidance to the quantification of proteomic data and could therefore facilitate the cutting-edge research in any pharmacoproteomic studies requiring SWATH-MS technique.</p