Young Cora J, Furdui Vasile I, Franklin James, Koerner Roy M, Muir Derek C G, Mabury Scott A
Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario, Canada M5S 3H6, CLF-Chem Consulting, 28 Rue Edouard Olivier, Brussels, Belgium.
Environ Sci Technol. 2007 May 15;41(10):3455-61. doi: 10.1021/es0626234.
Perfluorinated acids (PFAs) are ubiquitously found in water and biota, including remote regions such as the High Arctic. Under environmental conditions, PFAs exist mainly as anions and are not expected to be subject to long-range atmospheric transport in the gas phase. Fluorinated telomer alcohols (FTOHs) are volatile and can be atmospherically oxidized to form perfluorocarboxylic acids. Analogously, fluorosulfamido alcohols can be oxidized to form perfluorooctane sulfonate (PFOS). High Arctic ice caps experience contamination solely from atmospheric sources. By examining concentrations of PFAs in ice cap samples, it is possible to determine atmospheric fluxes to the Arctic. Ice samples were collected from high Arctic ice caps in the spring of 2005 and 2006. Samples were concentrated using solid-phase extraction and analyzed by LC-MS-MS. PFAs were observed in all samples, dating from 1996 to 2005. Concentrations were in the low-mid pg L(-1) range and exhibited seasonality, with maximum concentrations in the spring-summer. The presence of perfluorodecanoic acid (PFDA) and perfluoroundecanoic acid (PFUnA) on the ice cap was indicative of atmospheric oxidation as a source. Ratios of PFAs to sodium concentrations were highly variable, signifying PFA concentrations on the ice cap were unrelated to marine chemistry. Fluxes of the PFAs were estimated to the area north of 65 degrees N for the 2005 season, which ranged from 114 to 587 kg year(-1) for perfluorooctanoic acid (PFOA), 73 to 860 kg year(-1) for perfluorononanoic acid (PFNA), 16 to 84 kg year(-1) for PFDA, 26 to 62 kg year(-1) for PFUnA, and 18 to 48 kg year(-1) for PFOS. The PFOA and PFNA fluxes agreed with FTOH modeling estimations. A decrease in PFOS concentrations through time was observed, suggesting a fast response to changes in production. These data suggest that atmospheric oxidation of volatile precursors is a primary source of PFAs to the Arctic.
全氟辛酸（PFAs）广泛存在于水和生物群中，包括北极等偏远地区。在环境条件下，PFAs主要以阴离子形式存在，预计不会在气相中进行远距离大气传输。氟化调聚醇（FTOHs）具有挥发性，可在大气中被氧化形成全氟羧酸。类似地，氟磺酰胺醇可被氧化形成全氟辛烷磺酸（PFOS）。北极冰盖仅受到大气源的污染。通过检测冰盖样本中PFAs的浓度，可以确定进入北极的大气通量。2005年和2006年春季从北极冰盖采集了冰样本。样本通过固相萃取进行浓缩，并采用液相色谱-串联质谱进行分析。在所有可追溯到1996年至2005年的样本中均检测到了PFAs。浓度处于低至中等皮克每升（pg L(-1)）范围，并呈现季节性变化，春夏季浓度最高。冰盖上全氟癸酸（PFDA）和全氟十一烷酸（PFUnA）的存在表明大气氧化是一个来源。PFAs与钠浓度的比值变化很大，这表明冰盖上PFAs的浓度与海洋化学无关。估算了2005年季节北纬65度以北地区PFAs的通量，全氟辛酸（PFOA）的通量范围为每年114至587千克，全氟壬酸（PFNA）为每年73至860千克，PFDA为每年16至84千克，PFUnA为每年26至62千克，PFOS为每年18至48千克。PFOA和PFNA的通量与FTOH模型估算结果一致。观察到PFOS浓度随时间下降，这表明对生产变化反应迅速。这些数据表明，挥发性前体的大气氧化是北极PFAs的主要来源。
