Calibration of organic-diffusive gradients in thin films (o-DGT) passive samplers for perfluorinated alkyl acids in water. (January 2021)

• Record Type: Journal Article
• Authors: Wang, Po; Challis, Jonathan K.; Luong, Kim H.; Vera, Trisha C.; Wong, Charles S.
• Is Part Of: Chemosphere. Volume 263(2021)
• Publication Date: 2021-01
• Subjects: Organic-diffusive gradients in thin films -- Perfluorinated alkyl acids -- Diffusion coefficients -- Passive sampling; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2020.128325
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: The application of the organic-diffusive gradients in thin films (o-DGT) passive sampling technique for the monitoring of per- and polyfluoroalkyl substances (PFAS) in the environment is still limited. Six common PFAS with different chain lengths were evaluated in water by o-DGT. Measured diffusion coefficients (D) in agarose and polyacrylamide diffusive gels ranged from 4.55–8.63 × 10 −6 cm 2 s −1 and 3.85–7.00 × 10 −6 cm 2 s −1 at 23 °C, respectively. Experimental sampling rates (Rs) for both agarose- and polyacrylamide-WAX sampler configurations were within 22% relative error of D-based Rs for four of the PFAS. Larger differences for perfluorobutanesulfonic acid (PFBS) and perfluoroundecanoic acid (PFUnDA) ranged from 36% to 56%. In general, in-situ Rs can be predicted using measured D-values for perfluorinated alkyl acids. The mass accumulation of six PFAS in two o-DGT configurations was linear over 21 days (R 2 ≥ 0.97). Diffusion and uptake of o-DGT depended on the gel type and specific PFAS. Field demonstrations of o-DGT with WAX and HLB binding gels and polyacrylamide diffusive gels (not prone to biodegradation) found 0.3–19.5 ng L −1 of PFAS in rivers near industrial areas around Guangzhou and Foshan, China, with no apparent differences between the two co-deployed samplers. This study demonstrates that the configurations of o-DGT tested provide a cost-effective monitoring tool for measuring perfluorinated alkyl acids in aquatic systems, in particular the four PFAS for which reasonable correlations were observed. Graphical abstract: Image 1 Highlights: DGT (both agarose and polyacrylamide diffusive gels) were evaluated for six PFAS. Sampling rates were predictable from known aqueous diffusivity relations. Measured time-weighted-average values up to 20 ng L −1 in field evaluations. Both HLB and WAX sorbents effective for passive sampling of target PFAS by o-DGT.