Environmentally important perfluorinated carboxylates and sulfonates, as well as per- and polyfluorinated precursor compounds including several sulfonamides, telomer acids, and alcohols were determined in individual herring gull (Larus argentatus) eggs collected (in 2007) from 15 colonies located at Canadian and some American sites across the Laurentian Great Lakes of North America. The pattern of perfluorosulfonates (PFSAs; C6, C8, C10 chain lengths) was dominated by PFOS (> 90% of sigmaPFSA concentration) regardless of collection location. Concentrations of sigmaPFSA were significantly (p < 0.03) higher in eggs from Middle Island (western Lake Erie; 507 +/- 47 ng/g ww), Toronto Harbour (484 +/- 49 ng/g ww), and Strachan Island (486 +/- 59 ng/g ww) (Lake Ontario) compared to eggs from colonies on Lakes Superior, Michigan, and Huron. Perfluorocarboxylic acids (PFCAs) ranging in chain length from C8 to C15 were detected in the eggs, with PFUnA and PFTrA being the dominant compounds. PFOA and PFNA were more abundant in the sigmaPFCA in eggs from Lake Superior and Michigan colonies, and PFUnA and longer chain PFCAs were more abundant in the sigmaPFCA in eggs from Lake Erie and Ontario colonies. In contrast to sigmaPFSA, the highest concentrations of sigmaPFCA were found in eggs from Double Island, Lake Huron (113 +/- 12 ng/g ww) followed by eggs from colonies on Lakes Erie and Ontario. Among the PFOS or PFCA precursor compounds assessed (6:2, 8:2, and 10:2 fluorotelomer alcohols and acids and PFOSA), none were detectable in eggs from any sampling location. The exception was PFOSA (average concentration < 1 ng/g ww), which suggests that PFOS in the gulls and subsequently in their eggs may be due, in part, to biotransformation of PFOSA to PFOS in the gull and/or in their diet and food web. The accumulation of PFSA and PFCA from mainly aquatic dietary sources was suggested, and were highly lake- and/ or colony-dependent especially showing a northwest and southeast spatial trend and with higher concentrations in eggs from colonies in close proximity to highly urbanized and industrialized sites in Lakes Erie and Ontario.
"Detailed descriptions of sample extraction and instrumental analysis can be found elsewhere (Chu and Letcher, 2008; Gebbink et al., 2009, 2011a,b). In brief, approximately 1 g of homogenate was spiked with labeled internal standards and extracted with 3 mL of 0.2% (v/v) solution of formic acid in acetonitrile three times. "
"The extraction and clean-up of the samples was based on published methods (Gebbink et al., 2009, 2013). Briefly, homogenized food basket samples (2.5e5 g) were spiked with labeled internal standards (500 pg each) (see Table S1 for all internal standards used) and 6 mL acetonitrile were added. "
[Show abstract][Hide abstract] ABSTRACT: We analyzed food market basket samples obtained in Sweden from 1999, 2005, and 2010 for perfluoroalkyl acids (PFAAs) and a range of precursor compounds. Perfluorooctane sulfonic acid (PFOS) precursors were detected in all food year pools with the highest concentrations in 1999. Six polyfluoroalkyl phosphate diesters (diPAPs, 4:2/6:2, 6:2/6:2, 6:2/8:2, 8:2/8:2, 6:2/10:2, and 10:2/10:2) were detected in the year pools with the highest ∑diPAP concentrations in 1999 and 2005. All precursors were predominantly found in meat, fish, and/or eggs based on analysis of individual food groups from 1999. Based on year pools, PFOS precursors contributed between 4 and 1% as an indirect source to total dietary PFOS intakes between 1999 and 2010. Perfluorohexanoic acid (PFHxA) exposure originated entirely from diPAPs, whereas for perfluorooctanoic acid (PFOA) and perfluorodecanoic acid (PFDA), diPAPs contributed between 1 and 19% to total exposure. The lowest precursor contributions were generally seen in food samples from 2010.
"PFOA is different from other persistent organic pollutants in its hydrotrope property and can therefore aggregate in the liver and blood serum rather than in fatty tissues (Gebbink et al., 2009). Although the manufacture and use of PFOA are phasing out in some countries, PFOA has been frequently detected in drinking water (Post et al., 2009; Quinones and Snyder, 2009), biotas (Gebbink et al., 2009) and in people (Harada et al., 2007). However, PFOA is difficult to degrade using most conventional technologies (Vecitis et al., 2009). "
[Show abstract][Hide abstract] ABSTRACT: Perfluorooctanoic acid (PFOA) is recalcitrant to degrade and mineralize. Here, the effect of
temperature on the photolytic decomposition of PFOA was investigated. The decomposition
of PFOA was enhanced from 34% to 99% in 60 min of exposure when the temperature was
increased from 25 to 85°C under UV light (201–600 nm). The limited degree of decomposition
at 25°C was due to low quantum yield, which was increased by a factor of 12 at 85°C.
Under the imposed conditions, the defluorination ratio increased from 8% at 25°C to 50% at
85°C in 60 min. Production of perfluorinated carboxylic acids (PFCAs, C7–C5), PFCAs (C4–C3)
and TFA (trifluoroacetic acid, C2) accelerated and attained a maximum within 30 to 90 min
at 85°C. However, these reactions did not occur at 25°C despite extended irradiation to
180 min. PFOA was decomposed in a step-wise process by surrendering one CF2 unit. In
each cyclical process, increased temperature enhanced the quantum yields of irradiation
and reactions between water molecules and intermediates radicals. The energy consumption
for removing each μmol of PFOA was reduced from 82.5 kJ at 25°C to 10.9 kJ at 85°C
using photolysis. Photolysis coupled with heat achieved high rates of PFOA degradation and
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