Multi-residue analysis of emerging pollutants in benthic invertebrates by modified micro-quick-easy-cheap-efficient-rugged-safe extraction and nanoliquid chromatography–nanospray–tandem mass spectrometry analysis

Bioconcentration of pharmaceuticals by aquatic flora in an Australian river system

Pharmaceuticals are emerging contaminants in the environment and are a ubiquitous presence in rivers downstream of wastewater treatment plant outfalls. Questions remain about the persistence of pharmaceuticals in rivers, and the uptake and bioconcentration of pharmaceuticals by aquatic plants. Our study took place in the Yarrowee/Leigh/Barwon River system in southeastern Australia. We quantified the concentrations of five pharmaceuticals (carbamazepine, primidone, propranolol, tramadol, and venlafaxine) in surface water at five sites along a 144-km stretch of river, downstream of the presumed primary point source (a wastewater treatment plant outfall). We quantified pharmaceuticals in the leaves of two aquatic plant species (Phragmites australis and Vallisneria australis) sampled at each site, and calculated bioconcentration factors. All five pharmaceuticals were detected in surface waters, and the highest detected concentration exceeded 500 ng.L-1 (tramadol). Four of the pharmaceuticals (all except tramadol) were detected and quantified at all sites, including the furthest site from the outfall (144 km). Carbamazepine showed less attenuation with distance from the outfall than the other pharmaceuticals. Carbamazepine and venlafaxine were quantified in the leaves of both aquatic plant species (range: 10-31 ng.g-1), and there was evidence that bioconcentration factors increased with decreasing surface water concentrations. The study demonstrates the potential long-distance persistence of pharmaceuticals in river systems, and the bioconcentration of pharmaceuticals by aquatic plants in natural ecosystems. These phenomena deserve greater attention as aquatic plants are a potential point of transfer of pharmaceuticals from aquatic ecosystems to terrestrial food webs.

Validation of the Chemical and Biological Steps Required Implementing an Advanced Multi-Omics Approach for Assessing the Fate and Impact of Contaminants in Lagoon Sediments

The increasing use of chemicals requires a better understanding of their presence and dynamics in the environment, as well as their impact on ecosystems. The aim of this study was to validate the first steps of an innovative multi-omics approach based on metabolomics and 16S metabarcoding data for analyses of the fate and impact of contaminants in Mediterranean lagoons. Semi-targeted analytical procedures for water and sediment matrices were implemented to assess chemical contamination of the lagoon: forty-six compounds were detected, 28 of which could be quantified in water (between 0.09 and 47.4 ng/L) and sediment (between 0.008 and 26.3 ng/g) samples using the UHPLC-MS/MS instrument. In addition, a non-targeted approach (UHPLC-HRMS) using four different sample preparation protocols based on solid/liquid extractions or an automated pressurized fluid extraction system (EDGE®) was carried out to determine the protocol with the best metabolome coverage, efficiency and reproducibility. Solid/liquid extraction using the solvent mixture acetonitrile/methanol (50/50) was evaluated as the best protocol. Microbial diversity in lagoon sediment was also measured after DNA extraction using five commercial extraction kits. Our study showed that the DNeasy PowerSoil Pro Qiagen kit (Promega, USA) was the most suitable for assessing microbial diversity in fresh sediment.

Single injection LC-MS/MS analytical method for the quantification of diverse families of micropollutants, including PFAS and organotins, in Gammarus fossarum

Since the last decades, light has been shed on the pollution of aquatic ecosystems. Considering apolar compounds in water, analysis of the dissolved phase is not sufficient due to their possible bioaccumulation. Additional analysis of sediments, biota, or sentinel species is necessary. Among sentinel species, Gammarus fossarum is a small shrimp of 30 mg that lives naturally in the river. Its ability to bioaccumulate makes it a good bioindicator of river pollution. Nevertheless, micropollutants are difficult to extract from gammarids due to their small size and their high level of lipids. Extracted interferences can lead to analytical difficulties. Targeted micropollutants in this work were organotins, personal and pharmaceutical care products (PPCPs), pesticides, flame retardants, and perfluorinated compounds. A sample preparation based on QuEChERS followed by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) was developed: different salts (acetate and citrate) and purification (addition of hexane, dispersive SPE) were tested and validated. Targeted molecules used to be analyzed by LC-MS/MS, except organotins which are principally analyzed in gas chromatography. One of the main challenges was to quantify them also in LC-MS/MS to implement an original multi-residue method. The analysis of 40 compounds was finally validated according to ICH guidelines, with LOQs ranging from 0.04 ng.g-1 to 313.5 ng.g-1. Regarding Perfluorooctanesulfonic acid (PFOS) and the sum of hexabromocyclododecane, LOQs reached the environmental quality standards in biota which are respectively of 9.1 and 167 ng.g-1. Finally, the method was applied to 15 real samples. Many compounds were quantified: perfluorinated compounds, drugs such as ketoprofen, and even cosmetics products such as octocrylene. This is the first study to quantify as many emerging compounds, especially organotins, in a sentinel species such as G. fossarum.

Application of a robust analytical method for quantifying progestins in environmental samples from three Portuguese Estuaries

In the last years, progestins have raised special concerns for their documented negative effects on aquatic species, yet little is known about their environmental levels in surface waters and bioaccumulation in the trophic web. This study aimed to 1) adapt an extraction method for quantifying progestins in freeze-dried matrices, 2) validate the analytical procedure for three matrices: bivalve, polychaete, and crustacean, and 3) characterize levels of the four most prescribed synthetic progestins in key species across three Portuguese estuaries. Through the validated method, progestins were only quantifiable for the crustacean. Values were generally low, peaking with drospirenone values in Ria de Aveiro (1.33 ± 0.26 ng/g ww) and Tagus estuary (1.42 ± 0.55 ng/g ww), while Ria Formosa exhibited the lowest progestin concentrations (< 1 ng/g ww). This study enabled the development of a precise extraction and analytical method for quantifying steroid hormones in three distinct biological matrices.

Speed it up: How temperature drives toxicokinetics of organic contaminants in freshwater amphipods

The acceleration of global climate change draws increasing attention towards interactive effects of temperature and organic contaminants. Many studies reported a higher sensitivity of aquatic invertebrates towards contaminant exposure with increasing or fluctuating temperatures. The hypothesis of this study was that the higher sensitivity of invertebrates is associated with the changes of toxicokinetic processes that determine internal concentrations of contaminants and consequently toxic effects. Therefore, the influence of temperature on toxicokinetic processes and the underlying mechanisms were studied in two key amphipod species (Gammarus pulex and Hyalella azteca). Bioconcentration experiments were carried out at four different temperatures with a mixture of 12 exposure relevant polar organic contaminants. Tissue and medium samples were taken in regular intervals and analysed by online solid-phase extraction liquid chromatography high-resolution tandem mass spectrometry. Subsequently, toxicokinetic rates were modelled and analysed in dependence of the exposure temperature using the Arrhenius equation. An exponential relationship between toxicokinetic rates versus temperature was observed and could be well depicted by applying the Arrhenius equation. Due to a similar Arrhenius temperature of uptake and elimination rates, the bioconcentration factors of the contaminants were generally constant across the temperature range. Furthermore, the Arrhenius temperature of the toxicokinetic rates and respiration was mostly similar. However, in some cases (citalopram, cyprodinil), the bioconcentration factor appeared to be temperature dependent, which could potentially be explained by the influence of temperature on active uptake mechanisms or biotransformation. The observed temperature effects on toxicokinetics may be particularly relevant in non-equilibrated systems, such as exposure peaks in summer as exemplified by the exposure modelling of a field measured pesticide peak where the internal concentrations increased by up to fourfold along the temperature gradient. The results provide novel insights into the mechanisms of chemical uptake, biotransformation and elimination in different climate scenarios and can improve environmental risk assessment.

Non-steroidal anti-inflammatory drugs caused an outbreak of inflammation and oxidative stress with changes in the gut microbiota in rainbow trout (Oncorhynchus mykiss)

One of the main contributors to pharmaceutical pollution of surface waters are non-steroidal anti-inflammatory drugs (NSAIDs) that contaminate the food chain and affect non-target water species. As there are not many studies focusing on toxic effects of NSAIDs on freshwater fish species and specially effects after dietary exposure, we selected rainbow trout (Oncorhynchus mykiss) as the ideal model to examine the impact of two NSAIDs - diclofenac (DCF) and ibuprofen (IBP). The aim of our study was to test toxicity of environmentally relevant concentrations of these drugs together with exposure doses of 100× higher, including their mixture; and to deepen knowledge about the mechanism of toxicity of these drugs. This study revealed kidneys as the most affected organ with hyalinosis, an increase in oxidative stress markers, and changes in gene expression of heat shock protein 70 to be signs of renal toxicity. Furthermore, hepatotoxicity was confirmed by histopathological analysis (i.e. dystrophy, congestion, and inflammatory cell increase), change in biochemical markers, increase in heat shock protein 70 mRNA, and by oxidative stress analysis. The gills were locally deformed and showed signs of inflammatory processes and necrotic areas. Given the increase in oxidative stress markers and heat shock protein 70 mRNA, severe impairment of oxygen transport may be one of the toxic pathways of NSAIDs. Regarding the microbiota, an overgrowth of Gram-positive species was detected; in particular, significant dysbiosis in the Fusobacteria/Firmicutes ratio was observed. In conclusion, the changes observed after dietary exposure to NSAIDs can influence the organism homeostasis, induce ROS production, potentiate inflammations, and cause gut dysbiosis. Even the environmentally relevant concentration of NSAIDs pose a risk to the aquatic ecosystem as it changed O. mykiss health parameters and we assume that the toxicity of NSAIDs manifests itself at the level of mitochondria and proteins.

Occurrence and seasonal variation of several endocrine disruptor compounds (pesticides, bisphenols, musks and UV-filters) in water and sediments from the estuaries of Tagus and Douro Rivers (NE Atlantic Ocean coast)

Exposure of aquatic environments to emerging contaminants is a global issue, special relevant in many estuaries due to impacts from anthropogenic activity. The aim of this work was to evaluate thirty-seven endocrine disruptor chemicals (EDCs) from four different classes (pesticides, bisphenols, polycyclic musks and UV-filters) in water and sediment samples collected during one-year in the estuaries of Tagus and Douro Rivers located into the NE Atlantic Ocean coast. EDCs analysis was achieved afterward validation of a gas-chromatography mass spectrometry (GC-MS) method using Dispersive Liquid-Liquid Microextraction (DLLME) as extraction procedure for water samples, and Quick, Easy, Cheap, Efficient, Rugged and Safe (QuEChERS) combined with DLLME for sediments. Tagus estuary presented higher levels of contamination with pesticide residues and bisphenols (BPs) than the Douro estuary in both water and sediment samples. Contrariwise, levels and frequency of polycyclic musks (PCMs) and UV-filters (UVF) were slightly higher in Douro estuary. Levels of pesticide residues in both sediment and water samples, and levels of PCMs and UVF in water samples were higher in warmer seasons (summer and spring) than in colder ones (winter and autumn). The opposite was found in what respect levels of BPs in water and sediment samples, and PCMs and UVF levels in sediment samples. Although the levels found for each contaminant are low, usually in the order of a few ng/mL(g), the presence of a high number of toxic compounds is a source of concern and requires constant monitoring.

The wastewater micropollutant carbamazepine in insectivorous birds-an exposure estimate

Insects with aquatic life stages can transfer sediment and water pollutants to terrestrial ecosystems, which has been described for metals, polyaromatic hydrocarbons, and polychlorinated chemicals. However, knowledge of the transfer of aquatic micropollutants released by wastewater treatment plants is scarce despite some preliminary studies on their occurrence in riparian spiders. In our study, we address a major analytical gap focusing on the transfer of the micropollutant carbamazepine from the larvae to the adult midges of Chironomus riparius using an optimized QuEChERS extraction method and HPLC–MS/MS applicable to both life stages down to the level of about three individuals. We show that the uptake of carbamazepine by larvae is concentration-dependent and reduces the emergence rate. Importantly, the body burden remained constant in adult midges. Using this information, we estimated the daily exposure of insectivorous tree swallows as terrestrial predators to carbamazepine using the energy demand of the predator and the energy content of the prey. Assuming environmentally relevant water concentrations of about 1 μg/L, the daily dose per kilogram of body weight for tree swallows was estimated to be 0.5 μg/kg/day. At places of high water contamination of 10 μg/L, the exposure may reach 5 μg/kg/day for this micropollutant of medium polarity. Considering body burden changes upon metamorphosis, this study fills the missing link between aquatic contamination and exposure in terrestrial habitats showing that wastewater pollutants can impact birds’ life. Clearly, further analytical methods for biota analysis in both habitats are urgently required to improve risk assessment.

Systematic Underestimation of Pesticide Burden for Invertebrates under Field Conditions: Comparing the Influence of Dietary Uptake and Aquatic Exposure Dynamics

Pesticides used in agriculture can end up in nearby streams and can have a negative impact on nontarget organisms such as aquatic invertebrates. During registration, bioaccumulation potential is often investigated using laboratory tests only. Recent studies showed that the magnitude of bioaccumulation in the field substantially differs from laboratory conditions. To investigate this discrepancy, we conducted a field bioaccumulation study in a stream known to receive pollutant loadings from agriculture. Our work incorporates measurements of stream pesticide concentrations at high temporal resolution (every 20 min), as well as sediment, leaves, and caged gammarid analyses (every 2-24 h) over several weeks. Of 49 investigated pesticides, 14 were detected in gammarids with highly variable concentrations of up to 140 ± 28 ng/gww. Toxicokinetic modeling using laboratory-derived uptake and depuration rate constants for azoxystrobin, cyprodinil, and fluopyram showed that despite the highly resolved water concentrations measured, the pesticide burden on gammarids remains underestimated by a factor of 1.9 ± 0.1 to 31 ± 3.0, with the highest underestimations occurring after rain events. Including dietary uptake from polluted detritus leaves and sediment in the model explained this underestimation only to a minor proportion. However, suspended solids analyzed during rain events had high pesticide concentrations, and uptake from them could partially explain the underestimation after rain events. Additional comparison between the measured and modeled data showed that the pesticide depuration in gammarids is slower in the field. This observation suggests that several unknown mechanisms may play a role, including lowered enzyme expression and mixture effects. Thus, it is important to conduct such retrospective risk assessments based on field investigations and adapt the registration accordingly.

Recent Applications of Nano-Liquid Chromatography in Food Safety and Environmental Monitoring: A Review

In recent years, a trend toward instrument miniaturization has led to the development of new and sophisticated analytical systems, such as nano-liquid chromatography (nano-LC), which has enabled improvements of sensitivity, as well as chromatographic resolution. The growing interest in nano-LC methodology has resulted in a variety of innovative and promising applications. In this article, we review the applications of nano-LC separation methods coupled with mass spectrometry in the analysis of food and environmental samples. An assessment of sample preparation methods and analytical performance are provided, along with comparison to other, more established analytical techniques. Three main groups of compounds that are crucial for food safety assessment are considered in this review: pharmaceuticals (including antibiotics), pesticides, and mycotoxins. Recent practical applications of the nano-LC method in the determination of these compounds are discussed. Furthermore, we also focus on methods for the determination of various environmental contaminants using nano-LC methods. Future perspectives for the development of nano-LC methods are discussed.

Development of multi-residue extraction procedures using QuEChERS and liquid chromatography tandem mass spectrometry for the determination of different types of organic pollutants in mussel

This study aimed to develop multi-residue methods for the extraction of organic pollutants in mussels (Mytilus galloprovincialis), including 11 pharmaceuticals, 5 pesticides, 5 perfluoroalkyl substances (PFASs) and 2 illicit drugs. The combination of 4 different QuEChERS methods and 12 clean-ups (a total of 44 combinations) was tested. QuEChERS included acidified (AQ), non-acidified (SQ) and their miniaturized versions. The clean-ups included 6 different conventional dispersive solid phase extraction (dSPE) plus 2 enhanced matrix removal (EMR-Lipid) and 4 SPE procedures (including sorbents focused on phospholipid removal and polymer-based). After sample analysis via HPLC-MS/MS, the three methods that provided the best results were validated in terms of linearity, accuracy, precision, sensitivity and matrix effect. The methods selected were the combination of (i) SQ and EMR-Lipid, (ii) AQ and Z-sep+ bulk-based dSPE and (iii) AQ and graphitized carbon black (GCB)-based dSPE. Recoveries at two concentration levels (50 and 500 ng/g) ranged 54-124%, 59-124% and 60-127%, respectively, and limits of quantification (LOQs) were < 30 ng/g for most analytes using any of the methods. The three methods were tested in non-spiked mussel samples purchased in local markets, but organic pollutants were not detected in any sample. However, the methods probed to successfully extract a wide range of organic pollutants families in mussel samples from the market and from bioaccumulation trials.

Impacts of Neonicotinoids on Molluscs: What We Know and What We Need to Know

The broad utilisation of neonicotinoids in agriculture has led to the unplanned contamination of adjacent terrestrial and aquatic systems around the world. Environmental monitoring regularly detects neonicotinoids at concentrations that may cause negative impacts on molluscs. The toxicity of neonicotinoids to some non-target invertebrates has been established; however, information on mollusc species is limited. Molluscs are likely to be exposed to various concentrations of neonicotinoids in the soil, food and water, which could increase their vulnerability to other sources of mortality and cause accidental exposure of other organisms higher in the food chain. This review examines the impacts of various concentrations of neonicotinoids on molluscs, including behavioural, physiological and biochemical responses. The review also identifies knowledge gaps and provides recommendations for future studies, to ensure a more comprehensive understanding of impacts from neonicotinoid exposure to molluscs.

Toxicity of the Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) acetylsalicylic acid, paracetamol, diclofenac, ibuprofen and naproxen towards freshwater invertebrates: A review

Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) represent one of the main therapeutic classes of molecules contaminating aquatic ecosystems worldwide. NSAIDs are commonly and extensively used for their analgesic, antipyretic and anti-inflammatory properties to cure pain and inflammation in human and veterinary therapy. After use, NSAIDs are excreted in their native form or as metabolites, entering the aquatic ecosystems. A number of monitoring surveys has detected the presence of different NSAIDs in freshwater ecosystems in the ng/L - μg/L concentration range. Although the concentrations of NSAIDs in surface waters are low, the high biological activity of these molecules may confer them a potential toxicity towards non-target aquatic organisms. The present review aims at summarizing toxicity, in terms of both acute and chronic toxicity, induced by the main NSAIDs detected in surface waters worldwide, namely acetylsalicylic acid (ASA), paracetamol (PCM), diclofenac (DCF), ibuprofen (IBU) and naproxen (NPX), both singularly and in mixture, towards freshwater invertebrates. Invertebrates play a crucial role in ecosystem functioning so that NSAIDs-induced effects may result in hazardous consequences to the whole freshwater trophic chain. Acute toxicity of NSAIDs occurs only at high, unrealistic concentrations, while sub-lethal effects arise also at low, environmentally relevant concentrations of all these drugs. Thus, further studies represent a priority in order to improve the knowledge on NSAID toxicity and mechanism(s) of action in freshwater organisms and to shed light on their real ecological hazard towards freshwater communities.

A multiresidue method for the analysis of pesticides, polycyclic aromatic hydrocarbons, and polychlorinated biphenyls in snails used as environmental biomonitors

This paper reports an optimized multiresidue extraction strategy based on the Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) extraction procedure and on solid-phase microextraction (SPME) for the simultaneous screening of 120 pesticides, 16 polycyclic aromatic hydrocarbons, and 22 polychlorinated biphenyls from the terrestrial snail Helix aspersa. The optimized extraction method was based on QuEChERS using acetonitrile, followed by dispersive-Solid-phase extraction clean-up using primary secondary amine and octadecyl (C18) sorbents. The obtained extracts were analyzed by liquid chromatography coupled with tandem mass spectrometry and gas chromatography coupled with tandem mass spectrometry. This latest technique was preceded by a pre-concentration step using SPME with appropriate fibers. Afterwards, the method was validated for its linearity, sensitivity, recovery, and precision. Results showed high sensitivity, accuracy, and precision, with limits of detection and quantification lower than 20 ng g ^- 1 for most considered pollutants. Both inter and intra-day analyses revealed low relative standard deviation (%), which was lower than 20% for most targeted compounds. Moreover, the obtained regression coefficient (R²) was higher than 0.98 and the recoveries were higher than 60% for the majority of the assessed pollutants.

The risk of neonicotinoid exposure to shrimp aquaculture

Widespread agricultural use of systemic neonicotinoid insecticides has resulted in the unintended contamination of aquatic environments. Water quality surveys regularly detect neonicotinoids in rivers and waterways at concentrations that could impact aquaculture stock. The toxicity of neonicotinoids to non-target aquatic insect and crustacean species has been recognised, however, there is a paucity of information on their effect on commercial shrimp aquaculture. Here, we show that commercially produced shrimp are likely to be exposed to dietary, sediment and waterborne sources of neonicotinoids; increasing the risks of disease and accidental human consumption. This review examines indicators of sublethal neonicotinoid exposure in non-target species and analyses their potential usefulness for ecotoxicology assessment in shrimp. The identification of rapid, reliable responses to neonicotinoid exposure in shrimp will result in better decision making in aquaculture management.

Study of peak capacities generated by a porous layered radially elongated pillar array column coupled to a nano-LC system

The performance of a porous-layered radially elongated pillar (PLREP) array column in a commercial nano-LC system was examined by performing separation of alkylphenones and peptides.

A new multistep purification method for simultaneously determining organic ultraviolet absorbents in fish tissue

More information is required to improve our understanding of the presence of organic ultraviolet absorbents (UVAs) in organisms and the risks posed to biota. Effective removal of lipids in the determination of UVAs in biological samples is a sample-processing bottleneck. In this study, we optimized a multistep purification method for fish tissue samples extracted using an ultrasonic-assisted extraction method. The purification method involved performing Florisil column chromatography, redissolving the extract in ethanol, and then performing dispersive solid-phase extraction using primary and secondary amine, Florisil, and C₁₈ silica sorbents. The purified samples were analyzed by gas chromatography-mass spectrometry. The method was effective and reliable, and was used to detect trace concentrations (ng/g) of 12 UVAs in fish tissue samples. The mean recovery range of the UVAs in fish tissue extracts was 65.4-118%, and the method detection limit range was 0.20-2.50 ng/g dw. The validated method was used to analyze 12 UVAs in fish samples from a local supermarket.

Internal Concentrations in Gammarids Reveal Increased Risk of Organic Micropollutants in Wastewater-Impacted Streams

Internal concentrations link external exposure to the potential effect, as they reflect what the organisms actually take up and experience physiologically. In this study, we investigated whether frequently detected risk-driving substances in water were found in the exposed organisms and if they are classified the same based on the whole body internal concentrations. Field gammarids were collected upstream and downstream of ten wastewater treatment plants in mixed land use catchments. The sampling was conducted in autumn and winter, during low flow conditions when diffuse agricultural input was reduced. The field study was complemented with laboratory and flume experiments to determine the bioaccumulation potentials of selected substances. For 32 substances, apparent bioaccumulation factors in gammarids were determined for the first time. With a sensitive multiresidue method based on online-solid phase extraction followed by liquid chromatography coupled to high resolution mass spectrometry, we detected 63 (semi-) polar organic substances in the field gammarids, showing higher concentrations downstream than upstream. Interestingly, neonicotinoids, which are particularly toxic toward invertebrates, were frequently detected and were further determined as major contributors to the toxic pressure based on the toxic unit approach integrating internal concentration and toxic potency. The total toxic pressure based on internal concentrations was substantially higher compared to when external concentrations were used. Thus, internal concentrations may add more value to the current environmental risk assessment that is typically based solely on external exposure.

Determination of selected emerging contaminants in freshwater invertebrates using a universal extraction technique and liquid chromatography accurate mass spectrometry

A simple sample preparation method based on a modified liquid-phase extraction approach to extract selected pharmaceuticals and personal care products from freshwater organisms is described. Extracted samples were analysed using liquid chromatography with Q-Exactive plus hybrid quadrupole Orbitrap mass spectrometry, using 2.6 μm C18 media. A 0.1% v/v acetic acid/acetonitrile mobile phase was applied over a 20 min gradient. Method detection limits in full scan mode were ca. 0.04-2.38 ng of analyte per g of sample. Linearity ranged from 0.9750 to 0.9996 over the calibration range of 0.01-100 μg/L; MS mass accuracy was <2 ppm for most analytes. This method was applied to quantify six pharmaceuticals and personal care products in seven invertebrate samples. For tandem mass spectrometry analysis, selection of precursor ions was performed for each pharmaceutical, with Mass Frontier software illustrating the fragmentation mechanism. Effects of collision energy on intensities of ions was further investigated. The tandem mass spectrometry condition resulting in the highest signal of respective selected product ion was selected to confirm each pharmaceutical, which was initially observed in the full scan mode. Results indicate that pharmaceuticals and personal care products found to be present in water-ways, may be incorporated into organisms that live in the environment of affected water streams.

A review of the pharmaceutical exposome in aquatic fauna

Pharmaceuticals have been considered 'contaminants of emerging concern' for more than 20 years. In that time, many laboratory studies have sought to identify hazard and assess risk in the aquatic environment, whilst field studies have searched for targeted candidates and occurrence trends using advanced analytical techniques. However, a lack of a systematic approach to the detection and quantification of pharmaceuticals has provided a fragmented literature of serendipitous approaches. Evaluation of the extent of the risk for the plethora of human and veterinary pharmaceuticals available requires the reliable measurement of trace levels of contaminants across different environmental compartments (water, sediment, biota - of which biota has been largely neglected). The focus on pharmaceutical concentrations in surface waters and other exposure media have therefore limited both the characterisation of the exposome in aquatic wildlife and the understanding of cause and effect relationships. Here, we compile the current analytical approaches and available occurrence and accumulation data in biota to review the current state of research in the field. Our analysis provides evidence in support of the 'Matthew Effect' and raises critical questions about the use of targeted analyte lists for biomonitoring. We provide six recommendations to stimulate and improve future research avenues.

Non-targeted investigation of benthic invertebrates (Chironomus riparius) exposed to wastewater treatment plant effluents using nanoliquid chromatography coupled to high-resolution mass spectrometry

Nanoliquid chromatography (nanoLC) was coupled to high-resolution mass spectrometry (HRMS) to perform a non-targeted investigation on benthic invertebrates, Chironomus riparius exposed to wastewater treatment plant (WWTP) effluents. Insect larvae represent a complex and low-weight matrix that required the use of a miniaturized Quick, Easy, Cheap, Effective, Rugged and Safe (QuEChERS) method of extraction followed by nanoLC-HRMS to perform the analysis. The optimization of this coupling in terms of separation conditions including trapping step, detection conditions and data treatment provided reproducible fingerprints on insect larvae exposed to WWTP effluents with both in situ and ex-situ approaches. Statistical treatments such as principal component analysis highlighted the impact of WWTP effluents on the metabolome of insect larvae and showed the influence of exposure conditions. The identification of discriminating signals (m/z, t_R) matched with several potential endogenous biomarkers. These are mainly fatty acids, indicating a change in lipid metabolism that can be correlated with exposure to WWTP effluents. Several xenobiotics have also been detected, including ibuprofen and propranolol, whose identities have been confirmed by analytical standards. This work demonstrates the effectiveness and sensitivity of nanoLC-HRMS based environmental non-targeted approaches in ecotoxicological studies and provides the first profiling data for a very small aquatic invertebrate.

A review of nanoscale LC-ESI for metabolomics and its potential to enhance the metabolome coverage

Liquid chromatography-electrospray ionisation-mass spectrometry (LC-ESI-MS) platforms are widely used to perform high throughput untargeted profiling of biological samples for metabolomics-based approaches. However, these LC-ESI platforms usually favour the detection of metabolites present at relatively high concentrations because of analytical limitations such as ion suppression, thus reducing overall sensitivity. To counter this issue of sensitivity, the latest in terms of analytical platforms can be adopted to enable a greater portion of the metabolome to be analysed in a single analytical run. Here, nanoflow liquid chromatography-nanoelectrospray ionisation (nLC-nESI), which has previously been utilised successfully in proteomics, is explored for use in metabolomic and exposomic research. As a discovery based field, the markedly increased sensitivity of these nLC-nESI platforms offer the potential to uncover the roles played by low abundant signalling metabolites (e.g. steroids, eicosanoids) in health and disease studies, and would also enable an improvement in the detection of xenobiotics present at trace levels in biological matrices to better characterise the chemical exposome. This review aims to give an insight into the advantages associated with nLC-nESI for metabolomics-based approaches. Initially we detail the source of improved sensitivity prior to reviewing the available approaches to achieving nanoflow rates and nanospray ionisation for metabolomics. The robustness of nLC-nESI platforms was then assessed using the literature available from a metabolomic viewpoint. We also discuss the challenging point of sample preparation which needs to be addressed to fully enjoy the benefits of these nLC-nESI platforms. Finally, we assess metabolomic analysis utilising nano scale platforms and look ahead to the future of metabolomics using these new highly sensitive platforms.

Small but with big impact? Ecotoxicological effects of a municipal wastewater effluent on a small creek

Municipal wastewater treatment plants (WWTPs) discharge micropollutants like pharmaceuticals, pesticides, personal care products or endocrine disrupting chemicals but also nutrients. Both can adversely influence the freshwater ecosystem and may finally affect the ecological conditions. Many studies focus on the potential impact of large WWTPs even if smaller ones are more common, often less efficient and discharge into small creeks or the upper reaches of rivers. As a result, the receiving waters are characterized by relatively high shares of treated wastewater. Thus, the primary objective of this study was to investigate the ecotoxicological effects of a small WWTP on freshwater amphipods and mollusks in a small creek using an active and passive monitoring approach, accompanied by laboratory experiments (LE). In vitro assays with recombinant yeasts and the microtox assay with Aliivibrio fischeri were performed in parallel to determine the endocrine potential and the baseline toxicity. The evaluation of the effects of the analysed WWTP was possible due to its shutdown during our study and the application of the same in vivo and in vitro assays before and after the shutdown. During the operation of the WWTP the discharge of treated wastewater caused significantly higher mortalities and lower reproduction of the anaylsed invertebrates in the active and passive montoring as well as in the LEs. Furthermore, the amphipod species assemblage in the creek was affected downstream of the WWTP effluent. Besides, the endocrine activity and baseline toxicity were significantly higher downstream of the effluent. After the shutdown of the WWTP, the in vitro activity levels and adverse in vivo effects in the receiving water recovered quickly with no significant differences downstream of the former WWTP effluent compared to the upstream station. Furthermore, the previously disturbed amphipod species assemblage recovered significantly with a shift in favor of Gammarus fossarum downstream of the effluent. These biological results are consistent with a marked decline by 81.5% for the detected micropollutants in the receiving creek after the shutdown which points to a prominent role of micropollutants for the observed effects.

Evaluation of the influence of surfactants in the bioaccumulation kinetics of sulfamethoxazole and oxazepam in benthic invertebrates

The potential ecotoxicological effects of mixtures of contaminants in the aquatic environment are generating a global concern. Benthic invertebrates, such as the crustacean Gammarus fossarum, are key in the functioning of aquatic ecosystems, and are frequently used as sentinel species of water quality status. The aim of this work was to study the effects of a mixture of the most frequently detected surfactants in the bioconcentration kinetics of two pharmaceuticals in G. fossarum, evaluating their potential enhancing or suppressing effects. Laboratory exposure experiments for both pharmaceuticals and surfactants (concentration ratio 1:25) were set up for two individual compounds, the anxiolytic oxazepam and the antibiotic sulfamethoxazole. Gammarid samples were processed using microQuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) extraction. Pharmaceuticals concentration in the organisms was followed-up by means of nanoliquid chromatography coupled to tandem mass spectrometry (nanoLC-MS/MS). Results indicated a similar mode of action of the surfactants in the bioconcentration kinetics of both drugs, decreasing the accumulation rate in the organism. Oxazepam showed a higher accumulation potential than sulfamethoxazole in all cases. Depuration experiments for oxazepam also demonstrated the high depurative capacity of gammarids, eliminating >50% of the concentration of oxazepam in <6h.

Nano-sized zeolites as modulators of thiacloprid toxicity on Chironomus riparius

This study investigated whether zeolites of different size (Y30 (nano-sized) and H-Beta(OH)-III (forming large aggregates/agglomerates composed of 50 nm small primary particles)) exerted acute toxicity on larvae of the non-biting midge, Chironomus riparius, and whether such zeolites are able to modulate the toxicity of a common insecticide, thiacloprid, by means of adsorption of a dissolved toxicant. We conducted acute toxicity tests with fourth instar larvae of C. riparius. In these tests, larvae were exposed to zeolites or thiacloprid solely, or to mixtures of both compounds. The mixtures comprised 1.0 µg/L thiacloprid in addition to low (5.2 mg/L), medium (18.2 mg/L), and high (391.7 mg/L) zeolite concentrations, resulting in different adsorption rates of thiacloprid. As biological endpoints, changes in mortality rates and in behavior were monitored every 24 h over a total investigation period of 96 h. Furthermore, we conducted chemical analyses of thiacloprid in the medium and the larvae and located the zeolite particles within the larvae by LA-ICP-MS imaging techniques. Our results demonstrate that both types of zeolites did not exert acute toxicity when applied as single-substances, but led to reduced acute toxicity of thiacloprid when applied together with thiacloprid. These results are in line with the sorption properties of zeolites indicating reduced bioavailability of thiacloprid, although our data indicate that thiacloprid can desorb from zeolites to some extent. While freely dissolved (i.e., non-sorbed) fraction of thiacloprid was a good parameter to roughly estimate toxic effects, it did not correlate with measured internal thiacloprid concentrations. Moreover, it was shown that both zeolite types were ingested by the larvae, but no indication for cellular uptake of them was found.

Determination of carbamazepine and 12 degradation products in various compartments of an outdoor aquatic mesocosm by reliable analytical methods based on liquid chromatography-tandem mass spectrometry

The aims of this work are to develop suitable analytical methods to determine the widely used anticonvulsant carbamazepine and 12 of its degradation/transformation products in water, sediment, fish (Gasterosteus aculeatus) and mollusc (Dreissena polymorpha). Protocols based on solid phase extraction for water, pressurized-liquid extraction for sediments and QuEChERS (quick easy cheap efficient rugged and safe) extraction for both organisms followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) are developed, validated and finally applied to samples collected during a 6-month experiment in outdoor mesocosms. Very low detection limits are reached, allowing environmentally realistic doses (namely, 0.05, 0.5 and 5 μg/L nominal concentrations) to be employed. The results indicate several metabolites and/or transformation products in each compartment investigated, with concentrations sometimes being greater than that of the parent carbamazepine. Biotic degradation of carbamazepine is demonstrated in water, leading to 10,11-dihydrocarbamazepine and 10,11-epoxycarbamazepine. In sediment, the degradation results in the formation of acridine, and 2- and 3-hydroxycarbamazepine. Finally, in both organisms, a moderate bioaccumulation is observed together with a metabolization leading to 10,11-epoxycarbamazepine in fish and 2-hydroxycarbamazepine in mollusc. Acridone is also present in fish. This study provides new and interesting data, helping to elucidate how chronic exposure to carbamazepine at relevant concentrations may affect impact freshwater ecosystems.

Nano-sized Al2O3 reduces acute toxic effects of thiacloprid on the non-biting midge Chironomus riparius

This study focuses on interactions between nanoparticles and a pesticide. The aim was to investigate how nano-sized aluminum oxide (410 nm) can alter the toxic effects of thiacloprid, even if no sorption between particles and the insecticide takes place. Thus, our study investigated a rather unexplored interaction. We conducted our research with larvae of Chironomus riparius and used thiacloprid as test substance as its toxicity to C. riparius is well described. The used nano-Al₂O₃ particles where chosen due to their suitable properties. For testing the acute effects of the interaction, we exposed larvae to thiacloprid (0.5, 1.0, 2.0, and 5.0 μg/L) and nano-Al₂O₃ (300 and 1000 mg/L), either solely or in binary mixtures. While thiacloprid resulted in elevated mortality, nano-Al₂O₃ solely did not exert any effects. Moreover, we observed an aggregation of nano-Al₂O₃ within the lumen of the intestinal tract of the larvae. Further results showed a significantly reduced mortality of fourth instar larvae when they were exposed to mixtures of nanoparticles and the pesticide, compared to thiacloprid alone. With increasing nano-Al₂O₃ concentration, this effect became gradually stronger. Additionally, chemical analyses of internal thiacloprid concentrations implicate reduced uptake of thiacloprid in animals exposed to mixtures. However, as larvae exposed to thiacloprid concentrations > 0.5 μg/L showed severe convulsions, independent of the presence or concentration of nano-Al₂O_3, we assume that nano-Al₂O₃ leads to a delay of mortality and does not entirely prevent it. As sorption measurements on pristine or defecated nano-Al₂O₃ did not reveal any sorptive interaction with thiacloprid, we can exclude sorption-based reduction of thiacloprid bioavailability as a mechanism behind our results. Even though we used test substances which might not co-occur in the environment in the tested concentrations, our study gives evidence for an interaction besides adsorption, which is important to generally understand how nanoparticles might affect biota.

An overview to nano-scale analytical techniques: Nano-liquid chromatography and capillary electrochromatography

Nano-liquid chromatography (nano-LC) and CEC are microfluidic techniques mainly used for analytical purposes. They have been applied to the separation and analysis of a large number of compounds, e.g., peptides, proteins, drugs, enantiomers, antibiotics, pesticides, nutraceutical, etc. Analytes separation is carried out into capillaries containing selected stationary phase. The mobile phase is moved either by a pump (nano-LC) or by an EOF, respectively. The two tools can offer some advantages over conventional techniques, e.g., high selectivity, separation efficiency, resolution, short analysis time and consumption of low volumes of mobile phase. Flow rates in the range 50-800 nL/min are usually applied. The low flow rate reduces the chromatographic dilution increasing the mass sensitivity. Special attention must be paid in avoiding peak dispersion selecting the appropriate detector, injector and tube connection. Finally due to the low flow rate these microfluidic techniques can be easily coupled with mass spectrometry.

Impact of wastewater treatment plant discharge on the contamination of river biofilms by pharmaceuticals and antibiotic resistance

Wastewater treatment plants (WWTPs) are one of the main sources of pharmaceutical residue in surface water. Epilithic biofilms were collected downstream from 12 WWTPs of various types and capacities to study the impacts of their discharge through the changes in biofilm composition (compared to a corresponding upstream biofilm) in terms of pharmaceutical concentrations and bacterial community modifications (microbial diversity and resistance integrons). The biofilm is a promising indicator to evaluate the impacts of WWTPs on the surrounding aquatic environment. Indeed, the use of biofilms reveals contamination hot spots. All of the downstream biofilms present significant concentrations (up to 965ng/g) of five to 11 pharmaceuticals (among the 12 analysed). Moreover, the exposition to the discharge point increases the presence of resistance integrons (three to 31 fold for Class 1) and modifies the diversity of the bacterial communities (for example cyanobacteria). The present study confirms that the discharge from WWTPs has an impact on the aquatic environment.

Body burden of pesticides and wastewater-derived pollutants on freshwater invertebrates: Method development and application in the Danube River

While environmental risk assessment is typically based on toxicant concentrations in water and/or sediment, awareness is increasing that internal concentrations or body burdens are the key to understand adverse effects in organisms. In order to link environmental micropollutants as causes of observed effects, there is an increasing demand for methods to analyse these chemicals in organisms. Here, a multi-target screening method based on pulverised liquid extraction (PuLE) and a modified QuEChERS approach with an additional hexane phase was developed. It is capable to extract and quantify organic micropollutants of diverse chemical classes in freshwater invertebrates. The method was tested on gammarids from the Danube River (within the Joint Danube Survey 3) and target compounds were analysed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Furthermore, a non-target screening using high resolution-tandem mass spectrometry (LC-HRMS/MS) was conducted. A total of 17 pollutants were detected and/or quantified in gammarids at low concentrations. Pesticide concentrations ranged from 0.1 to 6.52 ng g(-1) (wet weight), those of wastewater-derived pollutants from 0.1 to 2.83 ng g(-1) (wet weight). The presence of wastewater-derived pollutants was prominent at all spots sampled. Using non-target screening, we could successfully identify several chlorinated compounds. These results demonstrate for the first time the presence of pesticides and wastewater-derived pollutants in invertebrates of the Danube River.

Quantification of emerging micropollutants in an amphipod crustacean by nanoliquid chromatography coupled to mass spectrometry using multiple reaction monitoring cubed mode

An innovative analytical method has been developed to quantify the bioaccumulation in an amphipod crustacean (Gammarus fossarum) of three micropollutants regarded as anthropic-pollution markers: carbamazepine, oxazepam, and testosterone. A liquid-liquid extraction assisted by salts, known as QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) was miniaturised and optimised, so it could be adapted to the low mass samples (approximatively 5mg dry weight). For this same reason and in order to obtain good sensitivity, ultra-trace analyses were carried out by means of nanoliquid chromatography. A preconcentration system by on-column trapping was optimised to increase the injection volume. In order to improve both sensitivity and selectivity, the multiple reaction monitoring cubed mode analyses (MRM(3)) were carried out, validated and compared to the classic MRM. To the best of our knowledge, this is the first time that MRM(3) is coupled to nanoliquid chromatography for the analysis and detection of organic micropollutants <300Da. The optimised extraction method exhibited recoveries superior to 80%. The limits of quantification of the target compounds were 0.3, 0.7 and 4.7ng/g (wet weight) for oxazepam, carbamazepine and testosterone, respectively and the limits of detection were 0.1, 0.3 and 2.2ng/g (wet weight), respectively. The intra- and inter-day precisions were inferior to 7.7% and 10.9%, respectively, for the three levels of concentration tested. The analytical strategy developed allowed to obtain limits of quantification lower than 1ng/g (wet weight) and to establish the kinetic bioconcentration of contaminants within G. fossarum.

Bioaccumulation and trophic magnification of pharmaceuticals and endocrine disruptors in a Mediterranean river food web

Increasing evidence exists that emerging pollutants such as pharmaceuticals (PhACs) and endocrine-disrupting compounds (EDCs) can be bioaccumulated by aquatic organisms. However, the relative role of trophic transfers in the acquisition of emerging pollutants by aquatic organisms remains largely unexplored. In freshwater ecosystems, wastewater treatment plants are a major source of PhACs and EDCs. Here we studied the entrance of emerging pollutants and their flow through riverine food webs in an effluent-influenced river. To this end we assembled a data set on the composition and concentrations of a broad spectrum of PhACs (25 compounds) and EDCs (12 compounds) in water, biofilm, and three aquatic macroinvertebrate taxa with different trophic positions and feeding strategies (Ancylus fluviatilis, Hydropsyche sp., Phagocata vitta). We tested for similarities in pollutant levels among these compartments, and we compared observed bioaccumulation factors (BAFs) to those predicted by a previously-developed empirical model based on octanol-water distribution coefficients (Dow). Despite a high variation in composition and levels of emerging pollutants across food web compartments, observed BAFs in Hydropsyche and Phagocata matched, on average, those already predicted. Three compounds (the anti-inflammatory drug diclofenac, the lipid regulator gemfibrozil, and the flame retardant TBEP) were detected in water, biofilm and (at least) one macroinvertebrate taxa. TBEP was the only compound present in all taxa and showed magnification across trophic levels. This suggests that prey consumption may be, in some cases, a significant exposure route. This study advances the notion that both waterborne exposure and trophic interactions need to be taken into account when assessing the potential ecological risks of emerging pollutants in aquatic ecosystems.

Determination of a broad spectrum of pharmaceuticals and endocrine disruptors in biofilm from a waste water treatment plant-impacted river

Wastewater treatment plants (WWTPs) are one of the main sources of pharmaceuticals and endocrine disrupting compounds in freshwater ecosystems, and several studies have reported bioaccumulation of these compounds in different organisms in those ecosystems. River biofilms are exceptional indicators of pollution, but very few studies have focused on the accumulation of these emerging contaminants. The objectives of this study were first to develop an efficient analytical methodology for the simultaneous analysis of 44 pharmaceuticals and 13 endocrine disrupting compounds in biofilm, and second, to assess persistence, distribution, and bioaccumulation of these contaminants in natural biofilms inhabiting a WWTP-impacted river. The method is based on pressurized liquid extraction, purification by solid-phase extraction, and analysis by ultra performance liquid chromatography coupled to a mass spectrometer (UPLC-MS/MS) in tandem. Recoveries for pharmaceuticals were 31-137%, and for endocrine disruptors 32-93%. Method detection limits for endocrine disruptors were in the range of 0.2-2.4 ng g(-1), and for pharmaceuticals, 0.07-6.7 ng g(-1). A total of five endocrine disruptors and seven pharmaceuticals were detected in field samples at concentrations up to 100 ng g(-1).