Trophic magnification and isomer fractionation of perfluoroalkyl substances in the food web of Taihu Lake, China.
Biomagnification of perfluoroalkyl substances (PFASs) are well studied in marine food webs, but related information in fresh water ecosystem and knowledge on fractionation of their isomers along the food web are limited. The distribution, bioaccumulation, magnification, and isomer fractionation of PFASs were investigated in a food web of Taihu Lake, China. Perfluorooctanesulfonate (PFOS) and perfluorocarboxylates (PFCAs) with longer carbon chain lengths, such as perfluorodecanoate (PFDA) and perfluoroundecanoate (PFUnA), were predominant in organisms, while perfluorohexanoate (PFHxA) and perfluorooctanoate (∑PFOA) contributed more in the water phase. The consistent profile signature of PFOA isomers in water phase with 3M electrochemical fluorination (ECF) products suggests that ECF production of PFOA still exists in China. Linear proportions of PFOA, PFOS and perfluorooctane sulfonamide (PFOSA) in the biota were in the range of 91.9-100%, 78.6-95.5%, and 72.2-95.5%, respectively, indicating preferential bioaccumulation of linear isomers in biota. Trophic magnification factors (TMFs) were estimated for PFDA (2.43), perfluorododecanoate (PFDoA) (2.68) and PFOS (3.46) when all biota were included, suggesting that PFOS and long-chained PFCAs are biomagnified in the fresh water food web. The TMF of PFOS isomers descended in the order: n-PFOS (3.86) > 3+5m-PFOS (3.35) > 4m-PFOS (3.32) > 1m-PFOS (2.92) > m2-PFOS (2.67) > iso-PFOS (2.59), which is roughly identical to their elution order on a FluoroSep-RP Octyl column, suggesting that hydrophobicity may be an important contributor for isomer discrimination in biota.
College of Environmental Science and Engineering, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, Key Laboratory of Pollution Processes and Environmental Criteria, Ministry of Education, Nankai University , Tianjin 300071, People's Republic of China.
Shuhong
S
Fang
Xinwei
X
Chen
Shuyan
S
Zhao
Yifeng
Y
Zhang
Weiwei
W
Jiang
Liping
L
Yang
Lingyan
L
Zhu
D017738:Alkanesulfonic Acids / Q000032:analysis*; D058448:Biota; D002210:Caprylates / Q000032:analysis*; D005591:Chemical Fractionation; D002681:China; D004784:Environmental Monitoring; D005466:Fluorocarbons / Q000032:analysis*; D020387:Food Chain; D005618:Fresh Water / Q000737:chemistry; D007536:Isomerism; D060106:Lakes / Q000737:chemistry*
D017738:Alkanesulfonic Acids; D002210:Caprylates; D005466:Fluorocarbons; C023036:perfluorooctanoic acid; C076994:perfluorooctane sulfonic acid