A multi-residue method for determination of 70 organic micropollutants in surface waters by solid-phase extraction followed by gas chromatography coupled to tandem mass spectrometry

An electrochemical sensor derived from Cu-BTB MOF for the efficient detection of diflubenzuron in food and environmental samples

Diflubenzuron is widely used as a benzoylurea insecticide, and its impact on human health should not be underestimated. Therefore, the detection of its residues in food and the environment is crucial. In this paper, octahedral Cu-BTB was fabricated using a simple hydrothermal method. It served as a precursor for synthesizing Cu/Cu₂O/CuO@C with a core-shell structure through annealing, creating an electrochemical sensor for the detection of diflubenzuron. The response of Cu/Cu₂O/CuO@C/GCE, expressed as ΔI/I₀ exhibited a linear correlation with the logarithm of the diflubenzuron concentration ranging from 1.0 × 10^-4 to 1.0 × 10^-12 mol·L^-1. The limit of detection (LOD) was determined to be 130 fM using differential pulse voltammetry (DPV). The electrochemical sensor demonstrated excellent stability, reproducibility, and anti-interference properties. Moreover, Cu/Cu₂O/CuO@C/GCE was successfully employed to quantitatively determine diflubenzuron in actual food samples (tomato and cucumber) and environmental samples (Songhua River water, tap water, and local soil) with good recoveries. Finally, the possible mechanism of Cu/Cu₂O/CuO@C/GCE for monitoring diflubenzuron was thoroughly investigated.

Design of a novel hapten and development of a sensitive monoclonal immunoassay for dicamba analysis in environmental water samples

Weed resistance to glyphosate has been a driving force behind the increased use of alternative herbicides in agriculture. Recently, dicamba-tolerant recombinant plants were introduced to the market, which may result in residues of this agrochemical contaminating environmental waters. Given that restrictions on the use of dicamba have consequently been established by regulatory agencies, it is therefore also desirable to conduct extensive controls on dicamba residues. Immunoassays are currently the most powerful bioanalytical technology for the rapid monitoring of chemical residues and contaminants. In the present study, a novel hapten was designed maintaining unaltered all the antigenic moieties of the target molecule, and this was used to generate high-affinity monoclonal antibodies against dicamba for the first time. Additionally, a collection of haptens with different linker composition or linker tethering site was synthesized and conjugated to proteins. Using these novel immunoreagents, a direct competitive enzyme-linked immunosorbent assay with a limit of detection for dicamba of 0.24 ng/mL was developed and validated. Analysis of water samples from different origins afforded recovery values between 90 % and 120 %, and coefficients of variation below 20 % were obtained. These results indicate that the developed immunochemical assay is suitable for the rapid determination of dicamba residues in environmental water samples.

Modified DLLME-GC-TQMS determination of pesticide residues in Gomti River, Lucknow, India: ecological risk assessment and multivariate statistical approach

This research article aims to establish an easy and well-defined analytical method for detection and quantification of multiclass pesticides in Gomti river water samples because the increased agricultural activities, industrialization, and urbanization had increased the presence of pesticides in the ecosystem which causes the depletion of water quality making it a global concern. The analytical method, vortex-assisted ultrasonication-based dispersive liquid-liquid microextraction-solidification of floating organic droplets (VAUS-DLLME-SFO) was optimized using one parameter at a time approach which gave the recovery between 69.45 and 114.15%, limit of detection (LOD), and limit of quantification (LOQ) 0.0011-0.0111 µg/L and 0.0033-0.0368 µg/L, respectively, and RSD in the range of 0.75-1.29 which shows sensitivity and accuracy better than earlier reported methods. The data obtained were subjected to measurement uncertainty, risk assessment, and multivariate statistical analysis to establish the robustness of the developed analytical method. The measurement uncertainty found was concluded to be in the acceptable range for analytical results. Furthermore, the real samples were analyzed and the associated value of the risk quotient was found to be less than 1, except for aquatic invertebrates, establishing the fact that the current concentration of pesticides has no such negative threat to flora and fauna. The possible source of pesticides in the Gomti river system was established by multivariate analysis. It was thus concluded that anthropogenic activity is responsible for the variable concentration of pesticides found in the sample.

Environmental levels of carbaryl impair zebrafish larvae behaviour: The potential role of ADRA2B and HTR2B

The insecticide carbaryl is commonly found in indirectly exposed freshwater ecosystems at low concentrations considered safe for fish communities. In this study, we showed that after only 24 h of exposure to environmental concentrations of carbaryl (0.066-660 ng/L), zebrafish larvae exhibit impairments in essential behaviours. Interestingly, the observed behavioural effects induced by carbaryl were acetylcholinesterase-independent. To elucidate the molecular initiating event that resulted in the observed behavioural effects, in silico predictions were followed by in vitro validation. We identified two target proteins that potentially interacted with carbaryl, the α2B adrenoceptor (ADRA2B) and the serotonin 2B receptor (HTR2B). Using a pharmacological approach, we then tested the hypothesis that carbaryl had antagonistic interactions with both receptors. Similar to yohimbine and SB204741, which are prototypic antagonists of ADRA2B and HTR2B, respectively, carbaryl increased the heart rate of zebrafish larvae. When we compared the behavioural effects of a 24-h exposure to these pharmacological antagonists with those of carbaryl, a high degree of similarity was found. These results strongly suggest that antagonism of both ADRA2B and HTR2B is the molecular initiating event that leads to adverse outcomes in zebrafish larvae that have undergone 24 h of exposure to environmentally relevant levels of carbaryl.

On the Redox-Activity and Health-Effects of Atmospheric Primary and Secondary Aerosol: Phenomenology

The RHAPS (Redox-Activity And Health-Effects Of Atmospheric Primary And Secondary Aerosol) project was launched in 2019 with the major objective of identifying specific properties of the fine atmospheric aerosol from combustion sources that are responsible for toxicological effects and can be used as new metrics for health-related outdoor pollution studies. In this paper, we present the overall methodology of RHAPS and introduce the phenomenology and the first data observed. A comprehensive physico-chemical aerosol characterization has been achieved by means of high-time resolution measurements (e.g., number size distributions, refractory chemical components, elemental composition) and low-time resolution analyses (e.g., oxidative potential, toxicological assays, chemical composition). Preliminary results indicate that, at the real atmospheric conditions observed (i.e., daily PM1 from less than 4 to more than 50 μg m−3), high/low mass concentrations of PM1, as well as black carbon (BC) and water soluble Oxidative Potential (WSOP,) do not necessarily translate into high/low toxicity. Notably, these findings were observed during a variety of atmospheric conditions and aerosol properties and with different toxicological assessments. Findings suggest a higher complexity in the relations observed between atmospheric aerosol and toxicological endpoints that go beyond the currently used PM1 metrics. Finally, we provide an outlook to companion papers where data will be analyzed in more detail, with the focus on source apportionment of PM1 and the role of source emissions on aerosol toxicity, the OP as a predictive variable for PM1 toxicity, and the related role of SOA possessing redox-active capacity, exposure-response relationships for PM1, and air quality models to forecast PM1 toxicity.

Phenolic compounds in surface water: methodology and occurrence in Doce River, Brazil

Phenolic compounds are widely spread in surface water, mainly in developing countries, where sewage and wastewater treatment are still reduced. Thus, this work quantified these pollutants in the Doce River analyzing the associated risk for the environment and human health. This river is in the state of Minas Gerais in Brazil and was recently impacted by the collapse of a mining dam that compromised the resilience of the entire watershed. For that purpose, a methodology for simultaneous identification and quantification of 17 different phenols was developed. It was possible to verify phenolic compounds' occurrence with concentration ranging from 0.13 to 24.16 µg·L^-1. 2-Nitrophenol and bisphenol A appeared in all samples analyzed. The analytical method was processed using solid-phase extraction (SPE) (C₁₈ cartridge), gas chromatography with FID, and mass spectrometry to define the analytes' retention time. For case validation, the selectivity, linearity, detection and quantification limits, sensitivity, precision, accuracy, resolution, matrix effect, and peak quality were assessed. Four different solvents were tested in the recovery-grade trials, which were dichloromethane, methanol, acetonitrile, and ethyl acetate. Among them, methanol had a better performance and was used throughout all analyses. The phenolic compounds had a recovery degree higher than 50% after SPE, regardless of the matrices.

Development and validation of an analytical method for detection and quantification of benzophenone, bisphenol A, diethyl phthalate and 4-nonylphenol by UPLC-MS/MS in surface water

Guandu River is the main water source for 9 million inhabitants in Rio de Janeiro city and some others included in the metropolitan region of the Rio de Janeiro State, Brazil. Here, the development of a chromatographic method and its application to assess the occurrence of 4-nonylphenol (4NP), benzophenone (BP), bisphenol A (BPA) and diethyl-phthalate (DEP), known as endocrine disruptors (EDs), is reported. Sample were prepared by solid phase extraction (SPE) with C18 cartridge and methanol as elution solvent. Validation of analytical method followed the United States Environmental Protection Agency protocol (USEPA 8000D guide) and selectivity, matrix effect, linearity, precision, accuracy, robustness, limit of detection (LOD) and limit of quantification (LOQ) were evaluated. The recovery was greater than 90%, accuracy was found between 80% and 115% and relative standard deviation (RSD) below 11.03%. LOQ ranged from 10.0 to 50.0 ng L−1, while the LOD ranged from 0.87 to 5.72 ng L−1. The coefficients of determination (R2) were greater than 0.99 for all compounds within a linear ranges of 10.0 to 500 ng L−1 for 4NP and BP and 50.0 to 500 ng L−1 for BPA and DEP. The method was therefore considered selective and robust for all micropollutants. Matrix effect was observed for BP, 4NP and DEP. The developed method was applied to analyze five samples collected monthly during 2018 at a selected sampling point of a river in Rio de Janeiro State. The maximum concentrations found for BPA, BP, DEP and 4NP were 182.04, 286.20, 2.56×103 and 13.48 ng L−1 respectively. These values are high enough to justify an investigation on the presence of these micropollutants in drinking water as well as to extend the monitoring for the search of similar pollutants and their metabolites.

Polychlorinated biphenyls (PCBs) in water: method development and application to river samples from a populated tropical urban area

A method for the determination of polychlorinated biphenyls (PCBs) in water from urban rivers was implemented and validated. Extractions of dissolved and particulate PCBs were performed using solid-phase extraction and a pressurized solvent extraction system, respectively, and the analytes were identified and quantified by gas chromatography with tandem mass spectrometry in selected reaction monitoring mode with no further purification. The method was successfully developed for the determination of 41 PCBs with two precursor-product confirmations for each analyte. Low method detection limits (0.06-0.50 ng L^-1) and good precision (≤ 20%; n = 8) were obtained, as well a linear response of the calibration curve ranging from 1.0 to 50 ng L^-1. Method performance for real samples was tested with water collected weekly in triplicate during April 2018 from a eutrophic river in the city of Rio de Janeiro. The total (dissolved + particulate) PCB concentrations ranged from 2.17 to 5.29 ng L^-1, above the threshold for river water quality standards in Brazil. Graphical abstract.

Polypyrrole nanotubes for electrochemically controlled extraction of atrazine, caffeine and progesterone

Polypyrrole (PPy) was electrochemically synthesized with charge control on the surface of a steel mesh. Two different morphologies (globular and nanotubular) were created and characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The modified electrodes were used as extraction phases in solid-phase extraction (SPE) and electrochemically controlled solid-phase extraction (EC-SPE) of atrazine, caffeine and progesterone. Raman spectroscopy was employed for the structural characterization of PPy after long exposure to the analytes. The electrochemical behavior was studied by cyclic voltammetry which revealed the higher capacitive behavior of polypyrrole nanotubes because of the huge superficial area, also no electrocatalytical behavior was observed evidencing the strong adsorption of the analytes on the PPy surface. The effects of the PPy oxidation state on the extraction performance were evaluated by in-situ electrochemical sorption experiments. The sorption capacity was evaluated by gas chromatography coupled to mass spectrometry (GC-MS). The method displays good stability, repeatability and reproducibility. The limits of detection range between 1.7-16.7 μg L^-1. Following the extraction of river water samples, it was possible to identify the presence of other endogenous organic compounds besides the analytes of interest. This indicates the potential of the method and material developed in this work. Graphical abstract Schematic representation of a steel mesh electrode covered with polypyrrole nanotubes used as extraction phase for separation of contaminants from aqueous samples. The oxidation level of polypyrrole was electrochemically tuned by which the adsorption of analytes is deeply affected.

Psychiatrics and selected metabolites in hospital and urban wastewaters: Occurrence, removal, mass loading, seasonal influence and risk assessment

The occurrence, removal, mass loading, seasonal influence and environmental risk assessment of nine psychiatric pharmaceuticals and four of their selected metabolites, were studied in one hospital and one urban wastewater treatment plant (WWTP) in Ioannina city, in northwestern Greece, providing information about the efficiency of the plants and their contribution into the final receiver's flow. Samples were collected from the influents and the effluents of the plants in different sampling campaigns, from July to December 2016. Analytical methodology was based on ultra-high performance liquid chromatography-Orbitrap high-resolution mass spectrometry, after solid-phase extraction through Oasis HLB cartridges. Concentrations in both WWTPs ranged between <LOQ and 1126.3 ng/L in the influents and between <LOQ and 1127.4 ng/L, in the effluents. Results indicated that venlafaxine and its metabolite O-desmethyl venlafaxine were the most frequently detected compounds in the influents and the effluents of both WWTPs. Metabolite to parent compound ratio ranged in the influents between 0.01 and 87.2 while in the effluents between 0.01 and 47.7. Based on mass loads in the influents, venlafaxine is consumed in high amounts (up to 67.1 mg/day/1000 inhab.), and consequently its metabolite O-desmethyl venlafaxine (up to 139.1 mg/day/1000 inhab.). Similarly to the influents, environmental emissions, were also higher for venlafaxine and O-desmethyl venlafaxine (10.1 and 13.3 mg/d/1000 inhab., respectively). Removal efficiencies in the hospital WWTP ranged from -100% to 98.9%, while in the city WWTP from -49.9% to 99.8%. Furthermore, an important outcome was the evaluation of the potential ecotoxicological risk, by means of risk quotients (RQs), where none of the target psychiatrics or their metabolites showed RQ above 1.

Determination of Ten Macrolide Drugs in Environmental Water Using Molecularly Imprinted Solid-Phase Extraction Coupled with Liquid Chromatography-Tandem Mass Spectrometry

With the extensive application of antibiotics in livestock, their contamination of the aquatic environment has received more attention. Molecularly imprinted polymer (MIP), as an eco-friendly and durable solid-phase extraction material, has shown great potential for the separation and enrichment of antibiotics in water. This study aims at developing a practical and economical method based on molecularly imprinted solid phase extraction (MISPE) combined with liquid chromatography-tandem mass spectrometry (LC-MS/MS) for simultaneously detecting ten macrolide drugs in different sources of water samples. The MIP was synthesized by bulk polymerization using tylosin as the template and methacrylic acid as the functional monomer. The MIP exhibited a favorable load-bearing capacity for water (>90 mL), which is more than triple that of non-molecularly imprinted polymers (NIP). The mean recoveries of macrolides at four spiked concentration levels (limit of quantification, 40, 100, and 400 ng/L) were 62.6–100.9%, with intra-day and inter-day relative standard deviations below 12.6%. The limit of detection and limit of quantification were 1.0–15.0 ng/L and 3.0–40.0 ng/L, respectively. Finally, the proposed method was successfully applied to the analysis of real water samples.

Study of persistent toxic pollutants in a river basin-ecotoxicological risk assessment

This study presents a complementary approach for the evaluation of water quality in a river basin by employing active and passive sampling. Persistent toxic pollutants representing three classes: organochlorinated pesticides (OCPs), polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs), were studied in grab water samples, in passive samplers/SemiPermeable Membrane Devices (SPMDs) and in fish tissues collected along the Strymonas River, northern Greece at three sampling campaigns during the year 2013. Almost all the target compounds were detected in the study river of Strymonas, northern Greece at the periods of high rainfall intensity and/or low flow-rate. The most frequently detected compounds were 1,2-benzanthracene, benzo(a)pyrene, benzo(b)fluoranthene, endosulfan I, endosulfan II, endosulfan sulfate, endrin aldehyde, fluorene, methoxychlor, polychlorinated biphenyl PCB 28, PCB 180 and pyrene. The family of DDT compounds and aldrin were also occasionally detected. Agricultural run-off and waste effluents are the main sources of hydrophobic organic compounds in the river basin. The use of SPMDs allowed the detection of more micropollutants than active sampling (31 vs. 16, respectively). Results showed relatively low risk however the potential risk associated with micropollutants such as 1,2-benzanthracene, benzo(b)fluoranthene, p,p-dichlorodiphenyldichloroethane (DDD), endosulfan II, methoxychlor, PCB 180 and pyrene should not be neglected. Performing risk assessment based on passive sampling, more information was obtained about temporal and spatial variation. SPMDs could be applied as a pre-evaluation before chemical monitoring in biota.

Active and passive sampling for the assessment of hydrophilic organic contaminants in a river basin-ecotoxicological risk assessment

This study presents a complementary approach for the evaluation of water quality in a river basin by employing active and passive sampling. Thirty-eight hydrophilic organic compounds (HpOCs) (organohalogen herbicides, organophosphorous pesticides, carbamate, triazine, urea, pharmaceuticals, phenols, and industrial chemicals) were studied in grab water samples and in passive samplers POCIS collected along Strymonas River, Northern Greece, at three sampling campaigns during the year 2013. Almost all the target compounds were detected at the periods of high rainfall intensity and/or low flow rate. The most frequently detected compounds were aminocarb, carbaryl, chlorfenviphos, chloropropham, 2,4-D, diflubenzuron, diuron, isoproturon, metolachlor, and salicylic acid. Bisphenol A and nonylphenol were also occasionally detected. The use of POCIS allowed the detection of more micropollutants than active sampling. Low discrepancy between the concentrations obtained from both samplings was observed, at least for compounds with >50 % detection frequency; thus, POCIS could be a valuable tool for the selection and monitoring of the most relevant HpOCs in the river basin. Results showed relatively low risk from the presence of HpOCs; however, the potential risk associated with micropollutants such as carbaryl, dinoseb, diuron, fenthion, isoproturon, metolachlor, nonylphenol, and salicylic acid should not be neglected.

Pesticides in the surface waters of Lake Vistonis Basin, Greece: Occurrence and environmental risk assessment

A study was undertaken for the evaluation of the pesticide pollution caused by the agricultural activities in the basin of Lake Vistonis, Greece during the years 2010-2012. Water samples were collected from Lake Vistonis, four major rivers and various small streams and agriculture drainage canals. The concentration of 302 compounds was determined after solid-phase extraction of the water samples and subsequent LC-MS/MS and GC-MS/MS analysis of the extracts. Overall, herbicides were the most frequently detected pesticides (57%), followed by insecticides (28%) and fungicides (14%). In Lake Vistonis 11 pesticides were detected. Specifically, fluometuron was detected in the 75% of the samples (maximum concentration 0.088 μg/L) whereas lambda-cyhalothrin was detected in all the samples of spring 2011 and alphamethrin in all the samples of spring 2012 (maximum concentration 0.041 and 0.168 μg/L, respectively). In the rivers and drainage canals 68 pesticides were detected. Specifically, fluometuron was detected in the 53% of the samples (maximum concentration 317.6 μg/L) followed by chlorpyrifos and prometryn (16 and 13% of the samples respectively). An environmental risk assessment was performed by employing the Risk Quotient (RQ) method. The risk assessment revealed that at least one pesticide concentration led to a RQ>1 in 20% of the samples. In Lake Vistonis, alphamethrin and lambda-cyhalothrin concentrations resulted in RQ>1, whereas in the other water bodies this was mainly the result of chlorpyrifos-methyl and alphamethrin exposure. In contrast, herbicide and fungicide concentrations contributed substantially less to environmental risks.