No abstract

There is interest in the production, use, and environmental occurrence of perfluorinated compounds (PFCs) across Asia and the Asian contributions to the burden of these compounds reaching the Arctic and other remote regions via long-range transport. A spatial survey of perfluorinated compounds was therefore undertaken across China, India, and Japan in 2009 using passive air samplers. Target analytes were fluorotelomer olefins (FTOs), acrylates (FTAs), alcohols (FTOHs), sulfonamides, and sulfonamidoethanols. Wide variations in concentrations and mixtures of compounds were apparent from the study. Generally the FTOHs were the most abundant, followed by 8:2 FTO in China and Japan and by the sulfonamides in India. There was a general decline in PFC concentration from urban, rural, to remote locations. Background stations reflected regional differences in air mass composition. A site in the west Pacific Ocean exhibited a Japanese profile in which 8:2 FTO and 8:2 FTOH were predominant. In contrast, a southern Indian profile with high 4:2 FTOH concentrations was observed at a background site in southern China.

Results are reported from an ongoing passive air monitoring study for polycyclic aromatic compounds (PACs) in the Athabasca oil sands region in Alberta, Canada. Polyurethane foam (PUF) disk passive air samplers were deployed for consecutive 2-month periods from November 2010 to June 2012 at 17 sites. Samples were analyzed for polycyclic aromatic hydrocarbons (PAHs), alkylated PAHs, dibenzothiophene and its alkylated derivatives (DBTs). Relative to parent PAHs, alkylated PAHs and DBTs are enriched in bitumen and therefore considered to be petrogenic markers. Concentrations in air were in the range 0.03-210 ng/m(3), 0.15-230 ng/m(3) and 0.01-61 ng/m(3) for ∑PAHs, ∑alkylated PAHs and ΣDBTs, respectively. An exponential decline of the PAC concentrations in air with distance from mining areas and related petrogenic sources was observed. The most significant exponential declines were for the alkylated PAHs and DBTs and attributed to their association with mining-related emissions and near-source deposition, due to their lower volatility and greater association with depositing particles. Seasonal trends in concentrations in air for PACs were not observed for any of the compound classes. However, a forest fire episode during April to July 2011 resulted in greatly elevated PAH levels at all passive sampling locations. Alkylated PAHs and DBTs were not elevated during the forest fire period, supporting their association with petrogenic sources. Based on the results of this study, an "Athabasca PAC profile" is proposed as a potential source marker for the oil sands region. The profile is characterized by ∑PAHs/∑Alkylated PAHs = ∼0.2 and ∑PAHs/∑DBTs = ∼5.

Polyurethane foam (PUF) disk passive air samples, deployed during 2014 in the Global Atmospheric Passive Sampling (GAPS) Network, were analyzed for a range of flame retardants (FRs) including polybrominated diphenyl ethers (PBDEs), hexabromocyclododecane (HBCD), brominated and chlorinated novel FRs, and organophosphate esters (OPEs). Mean concentrations of PBDEs and novel FRs at the 48 sites monitored ranged from 0.097 to 93 pg/m for ΣPBDEs and from below detection limits to 126 pg/m for Σnovel FRs. For PBDEs, the detected concentrations were similar to those previously reported from samples collected in 2005 at GAPS sites, suggesting global background atmospheric concentrations of PBDEs have not declined since regulatory measures were implemented. OPEs were detected at every GAPS site, with ΣOPEs ranging from 69 to 7770 pg/m. OPE concentrations were at least an order of magnitude higher than the PBDEs. This study presents the first data on global distributions of OPEs in the atmosphere, obtained from a single passive sampling monitoring network. Challenges that can arise in passive air sampling campaigns are also highlighted and addressed with suggested recommendations for future campaigns.

Synthesis of Carbamates by Direct C-H Bond Activation of Formamides. -A wide range of β-ketoesters and 2-ketosubstituted phenols are effectively transformed into the corresponding carbamates in the reaction with formamides. The use of 6 equiv. of TBHP is crucial. Low yield of the product is observed when a cyclic diketone (IV) is applied. The method is extended to the preparation of a carbaryl insecticide derivative (XII). -(CHANG*, F.-R.; et al.; Eur.