Development and evaluation of passive sampling devices to characterize the sources, occurrence, and fate of polar organic contaminants in aquatic systems
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Date
2018
Authors
Challis, Jonathan K.
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Abstract
The primary goal of this dissertation was to develop and evaluate an improved
aquatic passive sampling device (PSD) for measurement of polar organic contaminants.
Chemical uptake of current polar-PSDs (e.g., POCIS – polar organic chemical integrative sampler) is dependent on the specific environmental conditions in which the sampler is deployed (flow-rate, temperature), leading to large uncertainties when applying laboratory-derived sampling rates in-situ. A novel configuration of the diffusive gradients in thin-films (DGT) passive sampler was developed to overcome these challenges. The organic-DGT (o-DGT) configuration comprised a hydrophilic-lipophilic
balance® sorbent binding phase and an outer agarose diffusive gel (thickness = 0.5–1.5
mm), notably excluding a polyethersulfone protective membrane which is used with all
other polar-PSDs. Sampler calibration exhibited linear uptake and sufficient capacity for
34 pharmaceuticals and pesticides over typical environmental deployment times, with
measured sampling rates ranging from 9–16 mL/d. Measured and modelled diffusion
coefficients (D) through the outer agarose gel provided temperature-specific estimates of o-DGT sampling rates within 20% (measured-D) and 30% (modelled-D) compared to
rates determined through full-sampler calibration. Boundary layer experiments in lab and field demonstrated that inclusion of the agarose diffusive gel negated boundary layer effects, suggesting that o-DGT uptake is largely insensitive to hydrodynamic conditions. The utility of o-DGT was evaluated under a variety of field conditions and
performance was assessed in comparison to POCIS and grab samples. o-DGT was
effective at measuring pharmaceuticals and pesticides in raw wastewater effluents, small creeks, large fast-flowing rivers, open-water lakes, and under ice at near-zero water temperatures. Concentrations measured by o-DGT were more accurate than POCIS when compared to grab samples, likely resulting from the influence in-situ conditions have on POCIS. Modelled sampling rates were successfully used to estimate semi-quantitative water concentrations of suspect wastewater contaminants using high-resolution mass spectrometry, demonstrating the unique utility of this o-DGT technique.
This dissertation establishes o-DGT as a more accurate, user-friendly, and widely
applicable passive sampler compared to current-use polar-PSDs. The o-DGT tool will
help facilitate more accurate and efficient monitoring efforts and ultimately lead to more
appropriate exposure data and environmental risk assessment.
Description
Keywords
Passive sampling, Polar organic contaminants, Pharmaceuticals, Pesticides, Aquatic systems, Wastewater, Environmental fate, Mass spectrometry, Lake Winnipeg, Red River
Citation
Challis, J.K., Cuscito, L.D., Joudan, S., Luong, K.H., Knapp, C.W., Hanson, M.L., Wong, C.S., 2018. Inputs, source apportionment, and transboundary transport of pesticides and other polar organic contaminants along the lower Red River, Manitoba, Canada. Science of the Total Environment. 635, 803–816. DOI: 10.1016/j.scitotenv.2018.04.128
Challis, J.K., Hanson, M.L., Wong, C.S., 2016. Development and Calibration of an Organic-Diffusive Gradients in Thin Films Aquatic Passive Sampler for a Diverse Suite of Polar Organic Contaminants. Analytical Chemistry. 88, 10583–10591. DOI: 10.1021/acs.analchem.6b02749
Challis, J.K., Hanson, M.L., Wong, C.S., 2018. Pharmaceuticals and pesticides archived on polar passive sampling devices can be stable for up to six years. Environmental Toxicology and Chemistry. 37, 762–767. DOI: 10.1002/etc.4012
Challis, J.K., Hanson, M.L., Wong, C.S., 2016. Development and Calibration of an Organic-Diffusive Gradients in Thin Films Aquatic Passive Sampler for a Diverse Suite of Polar Organic Contaminants. Analytical Chemistry. 88, 10583–10591. DOI: 10.1021/acs.analchem.6b02749
Challis, J.K., Hanson, M.L., Wong, C.S., 2018. Pharmaceuticals and pesticides archived on polar passive sampling devices can be stable for up to six years. Environmental Toxicology and Chemistry. 37, 762–767. DOI: 10.1002/etc.4012