An ultra-sensitive method for the analysis of perfluorinated alkyl acids in drinking water using a column switching high-performance liquid chromatography tandem mass spectrometry.
In epidemiological research, it has become increasingly important to assess subjects' exposure to different classes of chemicals in multiple environmental media. It is a common practice to aliquot limited volumes of samples into smaller quantities for specific trace level chemical analyses. A novel method was developed for the determination of 14 perfluorinated alkyl acids (PFAAs) in small volumes (10mL) of drinking water using off-line solid phase extraction (SPE) pre-treatment followed by on-line pre-concentration on a WAX column before analysis on column-switching high performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS). In general, large volumes (100-1000mL) have been used for the analysis of PFAAs in drinking water. The current method requires approximately 10mL of drinking water concentrated by using an SPE cartridge and eluted with methanol. A large volume injection of the extract was introduced on to a column-switching HPLC-MS/MS using a mix-mode SPE column for the trace level analysis of PFAAs in water. The recoveries for most of the analytes in the fortified laboratory blanks ranged from 73±14% to 128±5%. The lowest concentration minimum reporting levels (LCMRL) for the 14 PFAAs ranged from 0.59 to 3.4ng/L. The optimized method was applied to a pilot-scale analysis of a subset of drinking water samples from an epidemiological study. These samples were collected directly from the taps in the households of Ohio and Northern Kentucky, United States and the sources of drinking water samples are both surface water and ground water, and supplied by different water distribution facilities. Only five PFAAs, perfluoro-1-butanesulfonic acid (PFBS), perfluoro-1- -hexanesulfonic acid (PFHxS), perfluoro-1-octanesulfonic acid (PFOS), perfluoro-n-heptanoic acid (PFHpA) and perfluoro-n-octanoic acid (PFOA) are detected above the LCMRL values. The median concentrations of these five PFAAs detected in the samples was ≤4.1ng/L with PFOS at 7.6ng/L and PFOA at 10ng/L. Concentrations of perfluoro-1-decanesulfonic acid, PFDS and other perfluoroalkyl carboxylic acids were below the LCMRL values.
National Research Council, The National Academies of Sciences, Engineering, Medicine, 500 Fifth Street, NW, Washington, DC 20001, USA; National Risk Management Research Laboratory, U.S. Environmental Protection Agency, Cincinnati, OH, USA. Electronic address: dasu.kavitha@epa.gov.
Kavitha
K
Dasu
Centre for Health and Environmental Risk Research, National Institute for Environmental Studies, Tsukuba, Japan.
Shoji F
SF
Nakayama
Environmental Risk Research Center, Institute of Environmental Ecology, IDEA Consultants, Inc., Tokyo, Japan.
Mitsuha
M
Yoshikane
National Risk Management Research Laboratory, U.S. Environmental Protection Agency, Cincinnati, OH, USA.
Marc A
MA
Mills
National Center for Environmental Assessment, U.S. Environmental Protection Agency, Cincinnati, OH, USA.
J Michael
JM
Wright
Division of Biostatistics and Epidemiology, Cincinnati Children's Hospital Medical Center, University of Cincinnati, College of Medicine, Cincinnati, OH, USA.
Shelley
S
Ehrlich
D002851:Chromatography, High Pressure Liquid; D060766:Drinking Water / Q000737:chemistry*; D005466:Fluorocarbons / Q000032:analysis*; D012680:Sensitivity and Specificity; D052616:Solid Phase Extraction; D053719:Tandem Mass Spectrometry; D014874:Water Pollutants, Chemical / Q000032:analysis; D014881:Water Supply / Q000379:methods* / Q000592:standards
D060766:Drinking Water; D005466:Fluorocarbons; D014874:Water Pollutants, Chemical
Column-switching HPLC; Drinking water; Perfluorinated alkyl acids; Solid phase extraction