Gong, X; Liu, R; Li, Bin; Song, Y; Liu, Y
Perfluoroalkyl acids (PFAAs) in Daliao River system were simultaneously determined by UPLC-MS/MS coupled with SPE for water samples and with ultrasonication extraction for sediments. All samples were collected from the mainstreams of Hun River (HR) and Daliao River (DLR), as well as urban canal Xi River (XR) in Shenyang City, located in northeast China. Under the optimal conditions, the recoveries of most selected PFAAs were 61-131 % with RSD below 30 % for spiked water and sediment samples. The total average concentrations of PFAAs in surface water were 1.76-9.47 ng/L in the HR, 9.54-13.0 ng/L in the DLR and 33.5-50.7 ng/L in the XR. As the dominant PFAAs, perfluorooctanoic acid (PFOA) was detected at levels from 1.52 to 7.12 ng/L in the HR and DLR. PFOA, perfluoropentanoic acid (PFPA) and perfluorooctane sulfonic acid (PFOS) were the most abundant compounds detected in the XR with concentration ranges of 6.71-18.1, 9.7-26 and 0.81-13 ng/L, respectively. The average concentration of PFAAs in the sediments followed the sequence of the XR > DLR > HR. Perfluorodecanoic acid (PFHxA) was the dominant PFAA detected in 76.5 % of the sediment samples from the three rivers, with the concentrations of 0.07-0.49 ng/g dry mass. Both PFOS and PFOA were measurable in the sediments on very few occasions, with the concentration up to 0.84 ng/g dry mass. The calculated average partition coefficients (Log K-d, L/kg) of PFOA and PFOS between the sediment and water were 1.18 and 2.21, respectively. Given their exposure levels and risk quotient (RQ) values, PFOS and PFOA had no significant risk to aquatic organisms in the DLR system.
