To simplify on-site water sampling and screening, particularly in hard-to-reach or dangerous sites, a drone equipped with a hydrophilic–lipophilic balance (HLB), thin-film solid-phase microextraction (TF-SPME) sampler was developed. The drone-based sampler was shown to protect the sorbent phase from external contamination while preventing any detectable loss of components of a spiked modified McReynolds mixture on the membrane in the sampler for at least 10 min. HLB/poly(dimethylsiloxane) (PDMS) membranes deployed in flight on the drone sampler were demonstrated to extract disinfection by-products, including trichloromethane, dichloroacetonitrile, 1,1,1-trichloro-2-propanone, 2,2,2-trichloroethanol, benzonitrile, and benzyl nitrile, from hot tub water. When analyzed on-site, in duplicate, using hand-portable instrumentation, reasonably repeatable results were achieved (%relative standard deviations (RSD’s) 5–16%). Finally, drone TF-SPME sampling of an anthropogenically impacted watercourse indicated that impact from the suspected nearby landfill site was minimal, instead suggesting that internal combustion by-products from vehicles on the nearby Highway 401 played a much larger role in contaminating the watercourse. This conclusion was supported by the confirmed presence of BTEX, styrene, isopropylbenzene, propylbenzene, and 1,3,5-trimethylbenzene. In addition to immediately identifying these compounds on-site using portable gas chromatography–mass spectrometry (GC–MS), samples were taken back to the laboratory for benchtop analysis, further supporting this conclusion.
J. J. Grandy, V. Galpin, V. Singh, and J. Pawliszyn. Development of a Drone-Based Thin-Film Solid-Phase Microextraction Water Sampler to Facilitate On-Site Screening of Environmental Pollutants. Analytical Chemistry 2020. https://doi.org/10.1021/acs.analchem.0c01490