Isomer Profiles of Perfluoroalkyl Substances in Water and Soil Surrounding a Chinese Fluorochemical Manufacturing Park

Abstract

Despite that China is the largest global manufacturer of perfluoroalkyl substances (PFASs), the manufacturing methods and isomer purity of these chemicals are generally unknown. Here, sampling was conducted around a major fluorochemical manufacturing park in China in 2012, including soil and water collection inside the park, including from a wastewater treatment plant (WWTP), as well as in surrounding rivers and soil (∼15 km radius). Perfluoroalkyl sulfonates (PFSAs) were lower than perfluoroalkyl carboxylates (PFCAs) in all samples, and short-chain (C4-C6) PFCAs were predominant. Perfluoroalkyl phosphonates and phosphate diesters were occasionally detected, but at low detection frequency. Branched isomers of perfluorobutanesulfonate (PFBS) are reported for the first time, accounting for 15-27% of total PFBS in water. An enrichment of isopropyl-PFOA (28%) was found in WWTP influent, suggesting its manufacturing primarily by isopropyl telomerization. More numerous branched isomers were observed for the longer C9-C13 PFCAs (e.g., C12 PFCA had 16 branched isomers), including high proportions of one major branched isomer (likely isopropyl), possibly as impurities from isopropyl-PFOA manufacturing. Overall, short-chain perfluorinated acids were the predominant PFASs being released, but PFOA was still a major chemical in use at this site, primarily from isopropyl telomerization.

Levels, Isomer Profiles, and Estimated Riverine Mass Discharges of Perfluoroalkyl Acids and Fluorinated Alternatives at the Mouths of Chinese Rivers

“…The highly variable concentrations and homologue profiles of Σ 10 PFAAs demonstrate that the rivers are affected by different emission sources and that several rivers receive industrial discharges leading to elevated concentrations. 5,21,23,24,30 Overall, the range of PFAA levels in the Chinese rivers (sampled in 2013) was comparable to those reported in rivers from other countries sampled between 2005 and 2010. For example, the PFOA levels for 14 major European rivers in 2005−2006 ranged <0.65−23 ng/L with the exception of the Po River (200 ng/L) which was affected by a point source emission.…”

“…Site 5 is situated at the river mouth and the level increased to 49.9 ng/L, indicating significant sources such as fluorochemical manufacturing in the most eastern part of the river. 23,30 The most abundant PFAA was PFOA (AM 12.3 ng/L) contributing to about 40−56% of the total PFAAs in the Yangtze River ( Figure 3). These ranges were comparable to another study from 2013 where levels of Σ 18 PFASs ranged 14−32 ng/L at the main stream of the Yangtze River, with PFOA and PFBS as the dominating homologues.…”

Perfluoroalkyl and polyfluoroalkyl substances in the lower atmosphere and surface waters of the Chinese Bohai Sea, Yellow Sea, and Yangtze River estuary

“…Although the manufacturing of PFOS in China increased from 2002, the volume was much lower than it was globally before 2002 (MEP, 2008). Moreover, the introduction of a shorter-chained substitute resulted in higher PFBS concentrations than for PFOS in industrial parks (Chen et al, 2015;Jin et al, 2015) and inland lakes (for instance, the Tangxun Lake). As compared to PFOS, the voluntary phase-out of PFOA was executed much later (2015), and until recently, no global legislation had been proposed.…”

“…Hundreds of rivers in China as well as in the Korean Peninsula discharge industrial and domestic wastewater into this region (Jin et al, 2015;Kim, 2012;P. Wang et al, 2014).…”

Simultaneous qualitative and quantitative analysis of fluoroalkyl sulfonates in riverine water by liquid chromatography coupled with Orbitrap high resolution mass spectrometry

“…Novel isopropyl-branched fluorinated substances were initially found in river water by selected suspect-ion monitoring strategy [19], and non-target polyfluorinated sulfonic acid were identified in firefighter serum samples by retrospective screening of the full-scan MS 1 spectrum with the aid of advanced statistical analysis [20,21]. Nevertheless, additional LC-MS/MS methods were applied thereafter to quantify the emerging pollutants due to the concern of poor sensitivity and linear dynamic range of HRMS for quantitative purpose.…”