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

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.

Multicompartment and cross-species monitoring of contaminants of emerging concern in an estuarine habitat

The fate of many chemicals in the environment, particularly contaminants of emerging concern (CEC), have been characterised to a limited extent with a major focus on occurrence in water. This study presents the characterisation, distribution and fate of multiple chemicals including pharmaceuticals, recreational drugs and pesticides in surface water, sediment and fauna representing different food web endpoints in a typical UK estuary (River Colne, Essex, UK). A comparison of contaminant occurrence across different benthic macroinvertebrates was made at three sites and included two amphipods (Gammarus pulex &Crangon crangon), a polychaete worm (Hediste diversicolor) and a gastropod (Peringia ulvae). Overall, multiple contaminants were determined in all compartments and ranged from; Collapse

Key Words

• Environmental risk
• Invertebrate
• Occurrence
• Pesticides
• Pharmaceuticals
• Sediment

Collapse

MESH Headings

• Animals
• Ecosystem
• Environmental Monitoring
• Pesticides/analysis
• Rivers
• Water Pollutants, Chemical/analysis

Collapse

Grants

• MR/S019669/1 Medical Research Council

Collapse

Affiliation(s)

Thomas H Miller Department of Life Sciences, College of Health, Medicine and Life Sciences, Brunel University London, Kingston Lane, UB8 3PH, UK; Department of Analytical, Environmental & Forensic Sciences, School of Population Health & Environmental Sciences, Faculty of Life Sciences and Medicine, King's College London, 150 Stamford Street, London, SE1 9NH, UK.
Keng Tiong Ng Department of Analytical, Environmental & Forensic Sciences, School of Population Health & Environmental Sciences, Faculty of Life Sciences and Medicine, King's College London, 150 Stamford Street, London, SE1 9NH, UK; Environmental Research Group, School of Public Health, Faculty of Medicine, Imperial College London, UK
Aaron Lamphiere School of Life Sciences, University of Essex, Wivenhoe Park, Colchester, Essex, CO43SQ, UK
Tom C Cameron School of Life Sciences, University of Essex, Wivenhoe Park, Colchester, Essex, CO43SQ, UK
Nicolas R Bury School of Science, Technology and Engineering, University of Suffolk, James Hehir Building, University Avenue, Ipswich, Suffolk, IP3 0FS, UK; Suffolk Sustainability, University of Suffolk, Waterfront Building, Neptune Quay, Ipswich, IP4 1QJUK, UK
Leon P Barron Department of Analytical, Environmental & Forensic Sciences, School of Population Health & Environmental Sciences, Faculty of Life Sciences and Medicine, King's College London, 150 Stamford Street, London, SE1 9NH, UK; Environmental Research Group, School of Public Health, Faculty of Medicine, Imperial College London, UK

Collapse

Untargeted analysis of nanoLC-HRMS data by ANOVA-PCA to highlight metabolites in Gammarus fossarum after in vivo exposure to pharmaceuticals

In Western Europe, river water quality can be assessed using sentinel species such as the amphipod Gammarus fossarum. In this work of environmental metabolomics, the objective was to develop suitable chemometrics methods, using a limited number of individuals, to assess the modification of the metabolism of G. fossarum exposed to two human pharmaceuticals. Males and females gammarids were exposed to a mixture of the anxiolytic oxazepam and the antiepileptic carbamazepine (1000 ng L^-1) for 14 days under laboratory conditions according to a full factorial design 2² (repeated 5 times). They were analyzed at the single individual scale using a method including a μQuEChERS type extraction followed by a nanoliquid chromatography analysis coupled to high-resolution mass spectrometry. The molecular fingerprints obtained were investigated using XCMS. Several corrections of experimental drifts (by using lock mass and Quality Control samples) were tested prior to using APCA + method for the exploitation of the unbalanced designed data. Signal reproducibility was greatly improved by the lock mass normalisation. From the experimental design, a significant effect of both experimental factors "exposure to the mixture" and "gammarid gender" on the signals measured were highlighted by APCA+. Finally, the results obtained made it possible to identify variables responsible for each of the factor effects.

A rapid and easy method based on hydrophilic interaction chromatography coupled with tandem mass spectrometry (HILIC-MS/MS/MS) to quantify iodinated X-ray contrast in wastewaters

This work proposes the first method based on hydrophilic interaction liquid chromatography coupled to multiple reaction monitoring with triple stage fragmentation (HILIC-MRM³) to quantify polar organic micropollutants in complex sewage waters. A fast HILIC-MRM³ analytical method, without sample preparation except a dilution step, was developed and validated to quantify seven iodinated contrast media (ICMs) in sewage waters, namely iohexol, iomeprol, ioversol, iopamidol, diatrizoic acid, iopromide and iopentol. Several chromatographic columns and mobile phase conditions were investigated and a good separation of the ICMs was obtained with a mixed-mode column (Acclaim Mixed-mode WAX) used in HILIC conditions. The validation was performed using a synthetic matrix: the limits of quantification (LOQ) were inferior to 1 µg/L and the linearity of each compound was comprised within the [0.5-50] µg/L range. The applicability of the HILIC-MRM³ method was assessed by the analysis of several raw waters. The results highlighted the presence of ICMs in most samples, at concentrations up to several mg/L in hospital sewage waters.

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.

Uptake, biotransformation and elimination of selected pharmaceuticals in a freshwater invertebrate measured using liquid chromatography tandem mass spectrometry

Methods were developed to assess uptake and elimination kinetics in Gammarus pulex of nine pharmaceuticals (sulfamethazine, carbamazepine, diazepam, temazepam, trimethoprim, warfarin, metoprolol, nifedipine and propranolol) using targeted LC-MS/MS to determine bioconcentration factors (BCFs) using a 96 h toxicokinetic exposure and depuration period. The derived BCFs for these pharmaceuticals did not trigger any regulatory thresholds and ranged from 0 to 73 L kg^-1 (sulfamethazine showed no bioconcentration). Metabolism of chemicals can affect accurate BCF determination through parameterisation of the kinetic models. The added selectivity of LC-MS/MS allowed us to develop confirmatory methods to monitor the biotransformation of propranolol, carbamazepine and diazepam in G. pulex. Varying concentrations of the biotransformed products; 4-hydroxypropranolol sulphate, carbamazepine-10,11-epoxide, nordiazepam, oxazepam and temazepam were measured following exposure of the precursor compounds. For diazepam, the biotransformation product nordiazepam was present at higher concentrations than the parent compound at 94 ng g^-1 dw. Overall, the results indicate that pharmaceutical accumulation is low in these freshwater amphipods, which can potentially be explained by the rapid biotransformation and excretion.

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.

An innovative and integrative assay for toxicity testing using individual fish embryos. Application to oxazepam

This paper describes the development of an integrative embryo-toxicity assay in Japanese medaka allowing analysis of several toxicological endpoints together in a same individual. In this assay, embryos are topically exposed, and survival, hatching success, malformations, biometry, behaviour, and target gene expression are subsequently analysed in each individual. This assay was applied to oxazepam, an anxiolytic pharmaceutical compound currently found in wastewater treatment plant effluent. Even if oxazepam accumulation in embryos was very low, it caused spinal and cardiac malformations, delayed growth, erratic swimming and deregulation of genes involved in apoptosis, DNA repair and mitochondrial metabolism. Relationship between gene deregulation, abnormal behaviour, and developmental anomalies was demonstrated. This assay is sensitive enough to detect adverse effects at low chemical concentrations and at multiple endpoints in a unique fish embryo. This integrative embryo-toxicity assay is a powerful tool to characterize the spectrum of effects of new chemicals and also to link effects induced at different molecular, tissue and physiological levels.