Calibration and application of the Chemcatcher® passive sampler for monitoring acidic herbicides in the River Exe, UK catchment

et al. 2019

Environ Monit Assess

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Metaldehyde is recognised as an emerging contaminant. It is a powerful molluscicide and is the active compound in many types of slug pellets used for the protection of crops. The application of pellets to land generally takes place between August and December when slugs thrive. Due to its high use and physico-chemical properties, metaldehyde can be present in the aquatic environment at concentrations above the EU Drinking Water Directive limit of 100 ng L−1 for a single pesticide. Such high concentrations are problematic when these waters are used in the production of drinking water. Being able to effectively monitor this pollutant of concern is important. We compared four different monitoring techniques (spot and automated bottle sampling, on-line gas chromatography/mass spectrometry (GC/MS) and passive sampling) to estimate the concentration of metaldehyde. Trials were undertaken in the Mimmshall Brook catchment (Hertfordshire, UK) and in a feed in a drinking water treatment plant for differing periods between 17th October and 31st December 2017. This period coincided with the agricultural application of metaldehyde. Overall, there was a good agreement between the concentrations measured by the four techniques, each providing complementary information. The highest resolution data was obtained using the on-line GC/MS. During the study, there was a large exceedance (500 ng L−1) of metaldehyde that entered the treatment plant; but this was not related to rainfall in the area. Each monitoring method had its own advantages and disadvantages for monitoring investigations, particularly in terms of cost and turn-a-round time of data.Electronic supplementary materialThe online version of this article (10.1007/s10661-019-7221-x) contains supplementary material, which is available to authorized users.

Section: Resultssupporting

confidence: 54%

Section: Introductionmentioning

confidence: 99%

Comparison of different monitoring methods for the measurement of metaldehyde in surface waters

Castle

Mills²,

et al. 2019

Environ Monit Assess

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“…The use of another type of receiving phase in the Chemcatcher® (e.g. ion-exchange sorbents) could be used to overcome this issue (Townsend et al 2018 ). Methanol is a suitable extraction solvent and can recover ~ 100% of the sorbed analytes (Petrie et al 2016 ; Castle et al 2018a , b ).…”

Section: Resultsmentioning

confidence: 99%

Use of the Chemcatcher® passive sampler and time-of-flight mass spectrometry to screen for emerging pollutants in rivers in Gauteng Province of South Africa

Rimayi¹,

Chimuka

et al. 2019

Environ Monit Assess

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Many rivers in urbanised catchments in South Africa are polluted by raw sewage and effluent to an extent that their ecological function has been severely impaired. The Hennops and Jukskei Rivers lying in the Hartbeespoort Dam catchment are two of the worst impacted rivers in South Africa and are in need of rehabilitation. Passive sampling (Chemcatcher® with a HLB receiving phase) together with high-resolution tandem mass spectrometry–targeted screening was used to provide high sensitivity and selectivity for the identification of a wide range of emerging pollutants in these urban waters. Over 200 compounds, including pesticides, pharmaceuticals and personal care products, drugs of abuse and their metabolites were identified. Many substances (~ 180) being detected for the first time in surface water in South Africa. General medicines and psychotropic drugs were the two most frequently detected groups in the catchment. These accounted for 49% of the emerging pollutants found. Of the general medicines, antihypertensive agents, beta-blocking and cardiac drugs were the most abundant (28%) classes detected. The Hennops site, downstream of a dysfunctional wastewater treatment plant, was the most polluted with 123 substances detected. From the compounds detected, peak intensity–based prioritisation was used to identify the five most abundant pollutants, being in the order caffeine > lopinavir > sulfamethoxazole > cotinine > trimethoprim. This work provides the largest available high-quality dataset of emerging pollutants detected in South African urban waters. The data generated in this study provides a solid foundation for subsequent work to further characterise (suspect screening) and quantify (target analysis) these substances. Electronic supplementary material The online version of this article (10.1007/s10661-019-7515-z) contains supplementary material, which is available to authorized users.

“…Most routine monitoring procedures rely on the infrequent (typically monthly) collection of low-volume (~1 L) spot (bottle or grab) samples of water. This approach has a number of shortcomings when the concentration of substances is known to fluctuate widely or there are stochastic inputs of pollutants over time (Castle et al 2018a;Castle et al 2019;Townsend et al 2018). In order to overcome some of these difficulties, alternative monitoring strategies, such as the use of passive sampling devices has been proposed (Vrana et al 2005).…”

Section: Introductionmentioning

confidence: 99%

“…In the qualitative mode, they can be used simply to screen for the presence or absence of pollutants (Rimayi et al 2019). In the quantitative mode, they can yield time-weighted average (TWA) (Castle et al 2018a;Castle et al 2019;Townsend et al 2018) or equilibrium concentrations (Vrana et al 2005). To achieve this, the compound-specific sampler uptake rate (R s , mL day −1 ), diffusion coefficient or the sample/water partition coefficient (K sw ) needs to be determined previously in either the laboratory or in situ in the field (Booij et al 2007;Castle et al 2018b;Petrie et al 2016).…”

Section: Introductionmentioning

confidence: 99%

Detection of pharmaceuticals in wastewater effluents—a comparison of the performance of Chemcatcher® and polar organic compound integrative sampler

Fones

Greenwood

et al. 2020

Environ Sci Pollut Res

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Chemcatcher ® and POCIS passive sampling devices are widely used for monitoring polar organic pollutants in water. Chemcatcher ® uses a bound Horizon Atlantic™ HLB-L sorbent disk as receiving phase, whilst the POCIS uses the same material in the form of loose powder. Both devices (n = 3) were deployed for 21 days in the final effluent at three wastewater treatment plants in South Wales, UK. Following deployment, sampler extracts were analysed using liquid chromatography time-of-flight mass spectrometry. Compounds were identified using an in-house database of pharmaceuticals using a metabolomics workflow. Sixty-eight compounds were identified in all samplers. For the POCIS, substantial losses of sorbent (11-51%) were found during deployment and subsequent laboratory analysis, necessitating the use of a recovery factor. Percentage relative standard deviations varied (with 10 compounds exceeding 30% in both samplers) between individual compounds and between samplers deployed at the three sites. The relative performance of the two devices was evaluated using the mass of analyte sequestered, measured as an integrated peak area. The ratio of the uptake of the pharmaceuticals for the POCIS versus Chemcatcher ® was lower (1.84x) than would be expected on the basis of the ratio of active sampling areas (3.01x) of the two devices. The lower than predicted uptake may be attributable to the loose sorbent material moving inside the POCIS when deployed in the field in the vertical plane. In order to overcome this, it is recommended to deploy the POCIS horizontally inside the deployment cage.