DGT Passive Sampling for Quantitative in Situ Measurements of Compounds from Household and Personal Care Products in Waters

Abstract

Widespread use of organic chemicals in household and personal care products (HPCPs) and their discharge into aquatic systems means reliable, robust techniques to monitor environmental concentrations are needed. The passive sampling approach of diffusive gradients in thin-films (DGT) is developed here and demonstrated to provide in situ quantitative and time-weighted average (TWA) measurement of these chemicals in waters. The novel technique is developed for HPCPs, including preservatives, antioxidants and disinfectants, by evaluating the performance of different binding agents. Ultrasonic extraction of binding gels in acetonitrile gave good and consistent recoveries for all test chemicals. Uptake by DGT with HLB (hydrophilic-lipophilic-balanced) as the binding agent was relatively independent of pH (3.5-9.5), ionic strength (0.001-0.1 M) and dissolved organic matter (0-20 mg L), making it suitable for applications across a wide range of environments. Deployment time and diffusion layer thickness dependence experiments confirmed DGT accumulated chemicals masses are consistent with theoretical predictions. The technique was further tested and applied in the influent and effluent of a wastewater treatment plant. Results were compared with conventional grab-sampling and 24-h-composited samples from autosamplers. DGT provided TWA concentrations over up to 18 days deployment, with minimal effects from biofouling or the diffusive boundary layer. The field application demonstrated advantages of the DGT technique: it gives in situ analyte preconcentration in a simple matrix, with more quantitative measurement of the HPCP analytes.

Diffusive gradients in thin-films (DGT) for in situ sampling of selected endocrine disrupting chemicals (EDCs) in waters

“…The resins were pre-washed with MQ water, immersed in methanol, and then washed in MQ water before use. The diffusive gels, polyacrylamide gel (PA gel, 1.0 mm), agarose gel (AG gel, 1.5 % agarose, different thicknesses), and binding gels (0.4 mm, HLB, XAD18 and SXLA resins) were prepared according to previously published procedures (Chen et al 2017, Zhang andDavison 1999). The reagents used for gel making are described in the SD.…”

“…Over 700 papers have now been published using DGT, with over 300 users in more than 30 countries. Building on this track record, DGT has been developed more recently to sample a range of organic chemicals, including antibiotics (Chen et al 2015a, Chen et al 2012, Chen et al 2013, household and personal care products (Chen et al 2017), polar organic contaminants (Challis et al 2016), anionic pesticides (Guibal et al 2017), bisphenols (Zheng et al 2015), phenol and 4-chlorophenol (Dong et al 2014a, Dong et al 2014b, glyphosate and aminomethyl phosphonic acid (Fauvelle et al 2015) and illicit drugs (Guo et al 2017). This paper develops DGT for a very important new set of selected endocrine disrupting compounds.…”

Passive sampling of organic contaminants across the water-sediment interface of an urban stream

“…PSs virtually unaffected by hydrodynamics due to thick uptake limiting barriers are ceramic dosimeters (Bopp et al, 2005) and DGT for nutrients and trace metals (Davison and Zhang, 1994). More recent developments are DGT for organics (o-DGT) (Challis et al, 2016;Chen et al, 2014Chen et al, , 2013Chen et al, , 2012Chen et al, , 2018Chen et al, , 2017Guan et al, 2018;Guibal et al, 2017;Guo et al, 2017;Xie et al, 2018aXie et al, , 2018bZhang ` 5 et al, 1998) and a ceramic dosimeter for polar organics (Cristale et al, 2013). Although the use of such PSs might eliminate the need for calibration, uptake by these PSs is significantly reduced.…”

Diffusive gradients in thin films: devices, materials and applications

“…The ratio of EDCs concentrations obtained by XDA-1 DGT and direct sampling in seawater, were all between 0.8 and 1.2, which demonstrates that XDA-1 DGT is suitable for in situ measurement of EDCs in seawater (Xie et al 2018b). In addition, the concentration of household and personal care product (HPCP) compounds in water, were measured using DGT, in comparison with auto and grab sampling methods (Chen et al 2017b). Results suggested that concentrations of most HPCPs obtained by DGT are similar to those measured by auto sampling; however, they were not always consistent with the results of grab sampling, due to the grab sampling method ignoring some peak, point source, rain or discharge events.…”

“…Guibal et al (2017) utilized both Oasis ® HLB and Oasis ® MAX sorbent in DGT devices, to monitor anionic pesticides in rivers, with accuracies better than 30% found under the conditions of pH 3-8 and ionic strength 0.01-1 M NaNO 3 . The application of hydrophilic-lipophilic-balanced (HLB) binding agents has been reported for the measurement of household and personal care products (HPCPs) in waters, being effective in the pH range of 3.5-9.5, and ionic strengths of 0.001-0.1 M, with dissolved organic matter levels of 0-20 mg L −1 (Chen et al 2017b). Chen et al (2018c) further compared the performances of three different resins [HLB, XAD18 and Strata-XL-A (SXLA)] for measuring endocrine disrupting chemicals, showing that the measurements with HLB and XAD18 DGT were more stable than that of SXLA-DGT, with the tolerant pH range of 3.5-9.5 and ionic strength of 0.001-0.5 M. The use of DGT for measurement of organometallics have been optimized, with Cole et al (2018) using Bondesil ® C 8 silica particles as DGT sorbents for measurement of five organotin compounds in sediment, with performances effective within a range of pH 4-9 and ionic strength of 0.01-1 M NaCl.…”