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

Abstract

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.

Tap Water Contributions to Plasma Concentrations of Poly- and Perfluoroalkyl Substances (PFAS) in a Nationwide Prospective Cohort of U.S. Women

“…Variability between duplicates was less than 20% for all samples. Our method performance was comparable to a recently published ultrasensitive method for analyzing PFAS in small sample volumes (Dasu et al. 2017).…”

Online Solid-Phase Extraction LC-MS/MS: A Rapid and Valid Method for the Determination of Perfluorinated Compounds at Sub ng·L−1 Level in Natural Water

“…For PFOS, one of the most important analytes monitored, linearity of method was evaluated at low levels over concentration range from 0.2 to 250 ng•L −1 finding a linear response (correlation coefficients in Table 5). Generally, in the literature, detection limit for PFOS, by direct injection or SPE online, ranged from 5 to 10 ng•L −1 , and only few cases reported LOD at the level of 1 ng•L −1 [25,26]. In this context, quantification limits of 0.2 ng•L −1 without sample preparations can be considered an interesting analytical result.…”

“…Unfortunately, eluents at pH value above 8 are not totally compatible with classic C18 or polymeric columns employed in chromatographic separations. To the best of our knowledge, the best LOQ value for PFOS obtained by using SPE online technique values were reported at 1 ng•L −1 [25]. e research centre at ARPA Lombardia pioneers the monitoring of activities on superficial water samples on the Italian territory.…”

“…Recently, Dasu et al have reported an ultrasensitive method for the analysis of perfluorinated alkyl acids in drinking water using an SPE online column coupled with high-performance liquid chromatography-tandem mass spectrometry. is method uses water and methanol containing 0.1% of NH 4 OH [25] as mobile phases. Unfortunately, eluents at pH value above 8 are not totally compatible with classic C18 or polymeric columns employed in chromatographic separations.…”

Monitoring Analysis of Perfluoroalkyl Substances and F-53B in Bottled Water, Tea and Juice Samples by LC-MS/MS

“…[18][19][20] LC-MS/MS techniques have been used to evaluate several PFAS varieties in drinking water. [21][22][23] Unfortunately, previous methods were unsuccessful in determining PFAS limits and were burdened by cumbersome preparation methods. Thus, in the present study, monitoring analysis of fourteen PFAS, F-53B and dodecafluoro-3H-4,8-dioxanonanoate (ADONA) in drinking water, tea and juice samples was assessed using LC-MS/MS and solid-phase extraction (SPE) for application to establishing preliminary TDS.…”