Fluorotelomer Carboxylic Acids and PFOS in Rainwater from an Urban Center in Canada

摘要

A method based on LC/MS/MS analysis of fluorotelomer carboxylic acids (FTCAs:C_nF_(2n+1),CH_2COOH,n=6,8,and 10} and fluorotelomer unsaturated carboxylic acids (FTUCAs:C_nF_(2n)CHCOOH,n=6,8,and 10) in rainwater using negative ionization electrospray multiple reaction monitoring conditions is described.These compounds are thought to be oxidative products of atmospherically transported fluorotelomer alcohols (FTOHs:C_nF_(2n+1)CH_2CH_2OH).Preconcentration from rainwater samples collected in Winnipeg,Manitoba,Canada,was achieved using solid-phase extraction on C_(18) sorbent.Low parts per trillion levels of the do- and C_(12)-FTCAs and FTUCAs were detected,suggesting that one possible pathway of removing FTOHs from the atmosphere is through oxidation and wet deposition.Perfluorocarboxylic acids (PFCAs) and perfluo-rooctane sulfonate (PFOS) were simultaneously analyzed in the rainwater samples using established LC/MS/MS methods.PFOS was deposited in rainwater with a concentration of 0.59 ng/L while PFCAs were not detected above their respective method detection limits.