[Determination of eight neonicotinoid pesticides in wastewater by solid phase extraction combined with liquid chromatography-tandem mass spectrometry].

Neonicotinoid pesticides are a relatively new class of pesticides that have garnered significant attention owing to their potential ecological risks to nontarget organisms. A method combining solid phase extraction with liquid chromatography-tandem mass spectrometry (SPE-LC-MS/MS) was developed for the rapid and accurate detection of eight neonicotinoid pesticides (dinotefuran, E-nitenpyram, thiamethoxam, clothianidin, imidacloprid, imidaclothiz, acetamiprid, and thiacloprid) in wastewater. The chromatographic mobile phase and MS parameters were selected, and a single-factor method was used to determine the optimal column type, extraction volume, sample loading speed, and pH for SPE. The optimal parameters were as follows: column type, HLB column (500 mg/6 mL); sample extraction volume, 500 mL; sample loading speed, 10 mL/min; and sample pH, 6-8. The matrix effects of the wastewater samples were reduced by optimizing the chromatographic gradient-elution program, examining the dilution factor of the samples, and using the isotope internal standard calibration method. Prior to analysis, the wastewater samples were diluted 5-fold with ultrapure water for pretreatment. Subsequently, 2 mmol/L ammonium acetate aqueous solution containing 0.1% (v/v) formic acid and methanol was used as mobile phases for gradient elution on a ZORBAX Eclipse Plus C18 column (100 mm×2.1 mm, 1.8 µm). The samples were quantified using positive-ion multiple reaction monitoring (MRM) mode for 10 min. Imidacloprid-d4 was used as the isotope internal standard. The SPE process was further optimized by applying response surface methodology to select the type and mass of rinsing and elution solvents. The optimal pretreatment of the SPE column included rinsing with 10% methanol aqueous solution and elution with methanol-acetonitrile (1∶1, v/v) mixture (7 mL). The eight neonicotinoid pesticides showed satisfactory linearity within the relevant range, with linear correlation coefficients (r) all greater than 0.9990. The method detection limits (MDLs) ranged from 0.2 to 1.2 ng/L, and the method quantification limits (MQLs) ranged from 0.8 to 4.8 ng/L. The average recoveries of the eight neonicotinoid pesticides were in the range of 82.6%-94.2% at three spiked levels, with relative standard deviations (RSDs) ranging from 3.9% to 9.4%. Finally, the optimized method was successfully applied to analyze wastewater samples collected from four sewage treatment plants. The results indicated that the eight neonicotinoid pesticides could be generally detected at concentrations ranging from not detected (ND) to 256 ng/L. The developed method has a low MDL and high accuracy, rendering it a suitable choice for the trace detection of the eight neonicotinoid pesticides in wastewater when compared with other similar methods. The proposed method can be utilized to monitor the environmental impact and assess the potential risks of neonicotinoid pesticides in wastewater, thus promoting the protection of nontarget organisms and the sustainable use of these pesticides in agriculture.

Characterization of The Permeation Properties of Membrane Filters and Sorption Properties of Sorbents Used for Polar Organic Chemical Integrative Samplers.

Polar organic chemical integrative samplers (POCIS) are promising devices for measuring the time-weighted average concentrations of hydrophilic compounds in aquatic environments. However, the mechanisms underlying compound uptake by POCIS remain unclear. We investigated the permeation kinetics of polyethersulfone and polytetrafluoroethylene membrane filters, and the sorption kinetics of Oasis HLB (Waters), Envi-Carb (Supelco), and Oasis WAX (Waters) sorbents. The log octanol-water partition coefficient (KOW) values of the 19 targeted compounds ranged from -0.55 to 6.0. The overall mass-transfer coefficients were negatively correlated with KOW, indicating that interactions between hydrophobic compounds and the membrane inhibit permeation. The sorption rate coefficient showed no correlation with KOW and depended on the type of sorbent used. These results imply that the uptake of highly hydrophilic compounds by POCIS is determined by both the membrane and the sorbent kinetics; however, membrane kinetics dominate the uptake of hydrophobic compounds. Environ Toxicol Chem 2024;43:2115-2121. © 2024 SETAC.

Method optimization for a simultaneous determination of neonicotinoid, carbamate/thiocarbamate, triazole, organophosphate and pyrethroid pesticides and their metabolites in urine using UPLC-MS/MS.

An accurate and sensitive method for the determination of a total of 23 pesticides and their metabolites in human urine has been optimised. The methodology is based on a previously published method based on solid-phase extraction with methanol and acetone followed by ultra-performance liquid chromatography coupled to tandem mass spectrometry (UPLC-MS/MS) in the selected reaction mode (SRM) with both positive and negative electrospray ionization (ESI+/-). The detection settings of the previous method, which allowed to determine the metabolites from 6 organophosphate and 2 pyrethroid pesticides, were optimised in order to include further pesticide groups, such as 11 neonicotinoids, 3 carbamates/thiocarbamates and 2 triazoles. The 5-windows method enduring 22 min was optimized with acceptable results in relation to accuracy (recoveries >75 %), precision (coefficients of variation <26 %) and linearity (R2> 0.9915). The limits of detection ranged between 0.012 ng/mL and 0.058 ng/mL. Samples from the German External Quality Assessment Scheme (G-EQUAS) encompassing 2 pyrethroids, 2 organophosphate and one neonicotinoid (6-chloronicotinic acid, a common metabolite of imidacloprid and acetamiprid) were analysed, and the latter, included in this newest optimization, provided good reference results. The method is optimal as a human biomonitoring tool for health risk assessment in large population surveys.

Identification of the cytochrome P450 gene AccCYP6A13 in Apis cerana cerana and its response to environmental stress.

Cytochrome P450 plays a crucial role in regulating insect growth, development, and resisting a variety of stresses. Insect metamorphosis and response to external stress are altered by deleting CYP450 genes. In this study, we identified and analyzed a novel gene of CYP450 family, AccCYP6A13, from Apis cerana cerana, and explored its role in the response of Apis cerana cerana to adverse external stressors. It was found that the expression of AccCYP6A13 was spatiotemporal specificity. The expression level increased with age and reached its highest value in the adult stage. The primarily expressiong location were legs, brain, and epidermis of honeybees. Stress conditions can affect the expression of AccCYP6A13 depending on treatment times. RNA interference experiments have shown that knocking down AccCYP6A13 reduces antioxidant activity and deactivates detoxification enzymes, resulting in oxidative damage accumulation and a decline in detoxification capability in bees, as well as inhibiting numerous antioxidant genes. Additionally, knockdown of the AccCYP6A13 gene in Apis cerana cerana resulted in increased sensitivity to pesticides and increased mortality when treated with neonicotinoid pesticides such as thiamethoxam. AccCYP6A13 overexpression in a prokaryotic system further confirmed its role in resistance to oxidative stress. To summarize, AccCYP6A13 may play an essential role in the normal development and response to environmental stress in Apis cerana cerana. Furthermore, this study contributed to the theoretical understanding of bee resistance biology.

Determination of twelve neonicotinoid pesticides in chili using an improved QuEChERS method with UPLC-Q-TOF/MS.

In this study, a QuEChERS method based on citrate was developed and utilized for the analysis of twelve neonicotinoid pesticides in fresh red chilies, fresh green chilies, and dried chilies, coupled with ultra-high performance liquid chromatography quadrupole time of flight mass spectrometry (UPLC-Q-TOF/MS). In the sample preparation, acetonitrile containing 1% formic acid was used as the extraction solvent. Anhydrous sodium sulfate replaced the traditional anhydrous magnesium sulfate for water removal, effectively eliminating the issues of salt caking. Graphitized carbon black, octadecyl silica, and primary secondary amine were used as cleaning agents. The method showed good sensitivity, with the limits of quantification below 0.03 mg/kg for fresh chilies and below 0.15 mg/kg for dried chilies. Values of matrix effects ranged from -19.5% to 8.4%, and the recovery was 86.9% - 105.2%. The analytical method provided an effective tool for the high throughput detection of neonicotinoid pesticide residues in multiple chili matrices.

Development of Green and Facile Sample Preparation Method for Determination of Seven Neonicotinoids in Fresh Vegetables, and Dissipation and Risk Assessment of Imidacloprid and Dinotefuran.

A facile procedure for extracting and determining seven neonicotinoids was developed. Water was the only extraction solvent without phase separation and cleanup steps. The method was validated according to European Union standards, and the values obtained were compared with the criteria. The accuracy values were between 99.8% (thiamethoxam) and 106.8% (clothianidin) at the spiking levels of 0.01, 0.1, and 1 mg/kg in the tested matrices. The precision as pooled RSD values was ≤6.1% (intra-day) and ≤6.9% (inter-day). The limit of quantification was set and tested at 0.01 mg/kg. The matrix effect was evaluated, and all matrices had a suppressive effect. The matrix of the cucumber was the most effective, with -20.9% for dinotefuran and an average of -9.8% for all compounds, while the tomato matrix had the slightest effect. Real marketed samples were analyzed using the developed and QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) methods; the results were not significantly different. A supervised field trial was conducted in the open field to study the dissipation patterns of imidacloprid and dinotefuran in tomatoes. The dissipation of both compounds followed first-order kinetics. The half-life (T½) values were 3.4 and 2.5 days, with dissipation rates k of 0.2013 and 0.2781 days, respectively. Following the EU-MRL database, the calculated pre-harvest interval (PHI) values were 7 and 14 days for imidacloprid and dinotefuran, respectively, and 3 days for both compounds following Codex Alimentarius regulations. The risk of imidacloprid and dinotefuran residues was estimated from chronic and acute perspectives. The risk factors of dinotefuran were lower than those of imidacloprid. Nonetheless, the highest expected residues of both compounds were below the tolerance limits.

Associations between maternal serum neonicotinoid pesticide exposure during pregnancy and newborn telomere length: Effect modification by sampling season.

BACKGROUND: An increasing amount of evidence suggests that telomere length (TL) at birth can predict lifespan and is associated with chronic diseases later in life, but newborn TL may be affected by environmental pollutants. Neonicotinoids (NEOs) are widely used worldwide, and despite an increasing number of studies showing that they may have adverse effects on birth in mammals and even humans, few studies have examined the effect of NEO exposure on newborn TLs. OBJECTIVE: To investigate the effects of prenatal exposure to NEOs and the interactions between NEOs and sampling season on newborn TL. METHODS: We conducted a prospective cohort study of 500 mother-newborn pairs from the Guangxi Zhuang Birth Cohort. Ultraperformance liquid chromatographymass spectrometry was used to detect ten NEOs in maternal serum, and fluorescence quantitative PCR was used to estimate the newborn TL. A generalized linear model (GLM) was used to evaluate the relationships between individual NEO exposures and TLs , and quantile g-computation (Qgcomp) model and Bayesian kernel machine regression (BKMR) model were used to evaluate the combined effect of mixtures of components. RESULTS: The results of the GLM showed that compared with maternal TMX levels < LOD, maternal TMX levels < median were negatively correlated with newborn TL (-6.93%, 95% CI%: -11.92%, -1.66%), and the decrease in newborn TL was more pronounced in girls (-9.60%, 95% CI: -16.84%, -1.72%). Moreover, different kinds of maternal NEO exposure had different effects on newborn TL in different sampling seasons, and the effect was statistically significant in all seasons except in autumn. Mixed exposure analysis revealed a potential positive trend between NEOs and newborn TL, but the association was not statistically significant. CONCLUSION: Prenatal exposure to TMX may shorten newborn TL, and this effect is more pronounced among female newborns. Furthermore, the relationship between NEO exposure and TL may be modified by the sampling season.

Electrochemical sensing mechanisms of neonicotinoid pesticides and recent progress in utilizing functional materials for electrochemical detection platforms.

The excessive residue of neonicotinoid pesticides in the environment and food poses a severe threat to human health, necessitating the urgent development of a sensitive and efficient method for detecting trace amounts of these pesticides. Electrochemical sensors, characterized by their simplicity of operation, rapid response, low cost, strong selectivity, and high feasibility, have garnered significant attention for their immense potential in swiftly detecting trace target molecules. The detection capability of electrochemical sensors primarily relies on the catalytic activity of electrode materials towards the target analyte, efficient loading of biomolecular functionalities, and the effective conversion of interactions between the target analyte and its receptor into electrical signals. Electrode materials with superior performance play a crucial role in enhancing the detection capability of electrochemical sensors. With the continuous advancement of nanotechnology, particularly the widespread application of novel functional materials, there is paramount significance in broadening the applicability and expanding the detection range of pesticide sensors. This comprehensive review encapsulates the electrochemical detection mechanisms of neonicotinoid pesticides, providing detailed insights into the outstanding roles, advantages, and limitations of functional materials such as carbon-based materials, metal-organic framework materials, supramolecular materials, metal-based nanomaterials, as well as molecular imprinted materials, antibodies/antigens, and aptamers as molecular recognition elements in the construction of electrochemical sensors for neonicotinoid pesticides. Furthermore, prospects and challenges facing various electrochemical sensors based on functional materials for neonicotinoid pesticides are discussed, providing valuable insights for the future development and application of biosensors for simplified on-site detection of agricultural residues.

Internal multiple interactions-adsorption and external zwitterionic polymer-exclusion of restricted access materials as adsorbent for offline and online extraction of neonicotinoid pesticides in Goji samples.

A method based on novel restricted access materials (RAMs) for the determination of neonicotinoid pesticides in Goji samples using offline and online solid phase extraction (SPE) coupled with high-performance liquid chromatography (LC). RAMs were synthesized using poly(chloromethylstyrene-co-divinylbenzene) (PVBC/DVB) microspheres as substrate, styrene (St) and n-vinylpyrrolidone (NVP) were first copolymerized on the interior to construct adsorption sites, and sulfobetaine methacrylate (SBMA) was then polymerized on the exterior to form exclusion sites via two-step surface initiated-atom transfer polymerization. The prepared PVBC/DVB@poly(St-co-NVP)@poly(SBMA) RAMs could efficiently extract neonicotinoid pesticides and automatically exclude proteins. Under the optimized conditions, the developed methods of offline (magnetic SPE and SPE column) and online extraction coupled with LC both using PVBC/DVB@poly(St-co-NVP)@poly(SBMA) RAMs as the extractant, exhibit a wide linearity, low limits of detection and limit of quantification and good inter-day and intra-day precision with satisfactory recoveries. Among these methods, online extraction coupled with LC based on novel RAMs exhibits clear advantages for the determination of neonicotinoid pesticides in Goji samples has clear advantages, such as simple operation by direct injection, short extraction times, and high accuracy with less human error.

Surface-Enhanced Raman Spectroscopy Using a Silver Nanostar Substrate for Neonicotinoid Pesticides Detection.

Surface-enhanced Raman spectroscopy (SERS) has been introduced to detect pesticides at low concentrations and in complex matrices to help developing countries monitor pesticides to keep their concentrations at safe levels in food and the environment. SERS is a surface-sensitive technique that enhances the Raman signal of molecules absorbed on metal nanostructure surfaces and provides vibrational information for sample identification and quantitation. In this work, we report the use of silver nanostars (AgNs) as SERS-active elements to detect four neonicotinoid pesticides (thiacloprid, imidacloprid, thiamethoxam and nitenpyram). The SERS substrates were prepared with multiple depositions of the nanostars using a self-assembly approach to give a dense coverage of the AgNs on a glass surface, which ultimately increased the availability of the spikes needed for SERS activity. The SERS substrates developed in this work show very high sensitivity and excellent reproducibility. Our research opens an avenue for the development of portable, field-based pesticide sensors, which will be critical for the effective monitoring of these important but potentially dangerous chemicals.

Efficient degradation of imidacloprid by surface discharge cold plasma: Mechanism of interaction between ROS and molecular structure and evaluation of residual toxicity.

Incorrect use of neonicotinoid pesticides poses a serious threat to human and pollinator health, as these substances are commonly present in bee products and even drinking water. To combat this threat, the study developed a new method of degrading the pesticide imidacloprid using surface discharge cold plasma oxidation technology. The study showed that this method achieved a very high efficiency of imidacloprid degradation of 91.4%. The main reactive oxygen species (H2O2, O3, ·OH, O2-, 1O2) effectively participated in the decomposition reaction of imidacloprid. Reactive oxygen species were more sensitive to the structure of the nitroimine group. Density functional theory (DFT) further explored the sites of reactive oxygen species attack on imidacloprid and revealed the process of energy change of attacking imidacloprid. In addition, a degradation pathway for imidacloprid was proposed, mainly involving reactive oxygen species chemisorption, a ring-opening intermediate, and complete cleavage of the nitroimine group structure. Model predictions indicated that acute oral and developmental toxicity were significantly reduced after cold plasma treatment, as confirmed by insect experiments. Animal experiments have shown that plasma treatment reduces imidacloprid damage to mice hippocampal tissue structure and inhibits the reduction of brain-derived neurotrophic factor content, thus revealing the detoxification mechanism of the body.

Generalized Stressors on Hive and Forager Bee Colonies.

Hive-forming bees play an integral role in promoting agricultural sustainability and ecosystem preservation. The recent worldwide decline of several species of bees, and in particular, the honeybee in the United States, highlights the value in understanding possible causes. Over the past decade, numerous mathematical models and empirical experiments have worked to understand the causes of colony stress, with a particular focus on colony collapse disorder. We integrate and enhance major mathematical models of the past decade to create a single, analytically tractable model using a traditional disease modeling framework that incorporates both lethal and sublethal stressors. On top of this synthesis, a major innovation of our model is the generalization of stressor attributes including their transmissibility, impairment level, lethality, duration, and temporal-occurrence. Our model is validated against numerous emergent, biological characteristics and demonstrates that precocious foraging and labor destabilization can produce colony collapse disorder. The thresholds for these phenomena to occur depend on the characteristics and timing of the stressor, thus motivating further empirical and theoretical studies into stressor characteristics.

Biomimetic affinity sensor for the ultrasensitive detection of neonicotinoids.

Multiple pesticides are often used in combination to protect crops from pests. This makes rapid on-site detection of pesticide contamination challenging. Herein, we describe a method for simultaneous detection of diverse neonicotinoid pesticides using a sensor that combines neonicotinoid-specific odorant-binding protein 2 (OBP2), which was cloned from an insect chemical sensing protein and modified gold nanoparticles with local surface plasmon resonance (LSPR)-based digital nanoplasmonometry (DiNM). When neonicotinoid pesticides bind to OBP2 on gold nanoparticles, the induced LSPR shift peak wavelength is too small to be measured using conventional LSPR immunoassays. DiNM records and compares the scattered image intensity in two adjacent wavelength bands, A and B, centered on the LSPR peak. It considers both the peak shift and the relative intensity change in these two bands, resulting in a significant LSPR signal enhancement. Then the spectral-image contrast was computed as the signal response. Using this approach, we obtained excellent limits of detection (LODs) of 1.4, 1.5, and 4.5 ppb for the neonicotinoids imidacloprid, acetamiprid, and dinotefuran, respectively. Blind tests demonstrated high positive and negative rates for teas, approximately 85 and 100%, respectively. Recombinant OBP2 produced in E. coli offers several advantages over antibodies, including high yield, time savings, and cost effectiveness. Moreover, this method is highly selective and sensitive to neonicotinoids, making it practical for field use.

Relationship between photolysis mechanism and photo-enhanced toxicity to Vibrio Fischeri for neonicotinoids with cyano-amidine and nitroguanidine structures.

Neonicotinoids are widely used pesticides that contaminate aquatic environments. Although these chemicals can be photolyzed under sunlight radiation, it is unclear for the relationship between photolysis mechanism and toxicity change in aquatic organisms. This study aims to determine the photo-enhanced toxicity of four neonicotinoids with different main structures (acetamiprid, and thiacloprid for cyano-amidine structure, imidacloprid and imidaclothiz for nitroguanidine). To Achieve the goal, photolysis kinetics, effect of dissolved organic matter (DOM) and reactive oxygen species (ROSs) scavengers on photolysis rates, photoproducts, and photo-enhanced toxicity to Vibrio fischeri were investigated for four neonicotinoids. The results showed direct photolysis plays a key role in the photo-degradation of imidacloprid and imidaclothiz (photolysis rate constants are 7.85 × 10-3 and 6.48 × 10-3 min-1, respectively), while the photosensitization process of acetamiprid and thiacloprid was dominated by ·OH reactions and transformation (photolysis rate constants are 1.16 × 10-4 and 1.21 × 10-4 min-1, respectively). All four neonicotinoid insecticides exerted photo-enhanced toxicity to Vibrio fischeri, indicating photolytic product(s) posed greater toxicity than their parent compounds. The addition of DOM and ROS scavengers influenced photo-chemical transformation rates of parent compounds and their intermediates, leading to diverse effects on photolysis rates and photo-enhanced toxicity for the four insecticides as a result of different photo-chemical transformation processes. Based upon the detection of chemical structures of intermediates and Gaussian calculations, we observed different photo-enhanced toxicity mechanisms for the four neonicotinoid insecticides. Molecular docking was used to analyze the toxicity mechanism of parent compounds and photolytic products. A theoretical model was subsequently employed to describe the variability of toxicity response to each of the four neonicotinoids.

Acute thiamethoxam exposure induces hepatotoxicity and neurotoxicity in juvenile Chinese mitten crab (Eriocheir sinensis).

The similar nervous system structure between crustaceans and insects and the high-water solubility of thiamethoxam can lead to the more severe toxicity of thiamethoxam to crustaceans. However, the effects of thiamethoxam on crustaceans are unclear. Therefore, a 96-h acute toxicity test was performed to explore the hepatotoxicity and neurotoxicity effects of thiamethoxam on Chinese mitten crab (Eriocheir sinensis) at concentrations 0 µg/L, 150 µg/L and 300 µg/L. The antioxidant and detoxification systems (including phases I and II) were significantly activated after exposure of juvenile crabs to thiamethoxam for 24 h in 300 µg/L group, whereas the toxic activation effect in 150 µg/L group was delayed. Moreover, a similar pattern was observed for the transcription levels of immune-related genes. Further analysis of inflammatory signaling pathway-related genes showed that thiamethoxam exposure with 300 µg/L for 24 h may induce a pro-inflammatory response through the NF-κB pathway. In contrast, the gene expression levels in 150 µg/L group were significantly upregulated compared with 0 µg/L group after 96 h. In addition, although the acute exposure of 150 µg/L thiamethoxam did not seem to induce significant neurotoxicity, the acetylcholinesterase activity was significantly decreased in 300 µg/L group after thiamethoxam exposure for 96 h. Correspondingly, thiamethoxam exposure with 300 µg/L for 24 h resulted in significantly downregulated transcriptional levels of synaptic transmission-related genes (e.g. dopamine-, gamma-aminobutyric acid- and serotonin-related receptors). Therefore, thiamethoxam may be harmful and cause potential toxic threats such as neurotoxicity and metabolic damage to crustaceans.

Expression of subunits of an insecticide target receptor varies across tissues, life stages, castes, and species of social bees.

Global losses of insects jeopardize ecosystem stability and crop pollination. Robust evidence indicates that insecticides have contributed to these losses. Notably, insecticides targeting nicotinic acetylcholine receptors (nAChRs) have neurotoxic effects on beneficial insects. Because each nAChR consists of five subunits, the alternative arrangements of subunits could create a multitude of receptors differing in structure and function. Therefore, understanding whether the use of subunits varies is essential for evaluating and predicting the effects of insecticides targeting such receptors. To better understand how the use and composition of nAChRs differ within and between insect pollinators, we analysed RNA-seq gene expression data from tissues and castes of Apis mellifera honey bees and life stages and castes of the Bombus terrestris bumble bees. We reveal that all analysed tissues express nAChRs and that relative expression levels of nAChR subunits vary widely across almost all comparisons. Our work thus shows fine-tuned spatial and temporal expression of nAChRs. Given that coexpression of subunits underpins the compositional diversity of functional receptors and that the affinities of insecticides depend on nAChR composition, our findings provide a likely mechanism for the various damaging effects of nAChR-targeting insecticides on insects. Furthermore, our results indicate that the appraisal of insecticide risks should carefully consider variation in molecular targets.

Trace Immunosensing of Multiple Neonicotinoid Insecticides by a Novel Broad-Specific Antibody Obtained from a Rational Screening Strategy.

Residues of neonicotinoid pesticides have potential risks to food, environmental and biological safety. In this study, the hapten toward imidacloprid was adopted to gain antibodies. After molecular modeling, the electrostatic potentials of eight commonly-used neonicotinoid pesticides were individually calculated to analyze the structural similarity. Two representative compounds (imidacloprid and acetamiprid) with moderate similarity were rationally selected for hybridoma screening. Using this strategy, four clones of broad-specific monoclonal antibodies (mAbs) against multiple neonicotinoids were obtained, and the clone 6F11 exhibited the broadest spectrum to six neonicotinoid pesticides and two metabolites, with half-maximal inhibitory concentrations (IC50) ranging from 0.20 to 5.92 ng/mL. Then, the novel antibody gene was sequenced and successfully expressed in full-length IgG form using mammalian cells. Based on the sensitive recombinant antibody, a gold lateral-flow immunosensing strip assay was developed and it was qualified for rapid detection of imidacloprid, clothianidin or imidaclothiz residues in food samples.

Ethanol-ammonium sulfate system based modified quick, easy, cheap, effective, rugged, and safe method for the determination of four neonicotinoid pesticide and metabolite residues in two canned fruits.

As the pesticide and its metabolite residues in processed fruits could become a significant route of human exposure. The work presented herein focuses on developing a feasible quick, easy, cheap, effective, rugged, and safe method with improved extraction and cleanup system for the determination of imidacloprid, acetamiprid, thiamethoxam, and clothianidin (a metabolite of thiamethoxam) in canned fruits. The low toxic solvent ethanol was used to extract the analytes, and ammonium sulfate was used to promote phase separation. Moreover, the carboxylated multi-walled carbon nanotube acted as the clean-up sorbent for the removal of high solubility impurities. The proposed method was validated with fortified real samples at different concentration levels (20-200 µg/kg). Recoveries obtained from three spiked levels (20, 50, and 200 µg/kg) ranged from 74.9 to 86.4% with relative standard deviations of the intra-day and inter-day in the range of 0.8-5.5 and 2.0-7.1%, respectively. The limits of detection ranged from 0.2 to 0.5 and 0.2 to 0.6 µg/kg for orange and peach, respectively. The results demonstrated that the proposed method could be considered appropriate, and comparatively lower toxic for the analysis of neonicotinoid pesticide residues in canned fruit.

Enhanced removal of neonicotinoid pesticides present in the Decision 2018/840/EU by new sewage sludge-based carbon materials.

Due to the increasingly strict legislation about the disposal of sewage sludge, it is necessary to find sustainable solutions to manage this waste at low-cost conditions. In addition, priority contaminants are now attracting much attention since they are usually detected in WWTP effluents. In this work, five sludge have been used as precursors for the synthesis of activated carbons subsequently tested in the removal by adsorption of three neonicotinoid pesticides listed in the EU Watch List: acetamiprid (ACT), thiamethoxam (THM), and imidacloprid (IMD). Generally, the activated carbons were prepared by chemical activation using ZnCl2 as an activating agent and then the resulting materials were pyrolyzed at 800 °C for 2 h. The synthesized activated carbons showed different textural properties; thus, the best adsorption results were found for AC-Industrial activated carbon, obtained from an industrial origin sewage sludge, with high equilibrium adsorption capacities (qe = 104.2, 137.0, and 119.9 mg g-1), for ACT, THM, and IMD, respectively. Furthermore, it was elucidated that the use of CO2 in the synthesis generated an opening, followed by widening, of the narrowest microporosity, increasing the specific surface area of the carbon materials. The kinetic and isotherm adsorption experimental data were obtained for each of the pesticide-activated carbon systems; thus, the kinetic curves were well-fitted to the pseudo-second-order kinetic model, as well as, Freundlich and Guggenheim-Anderson-de Boer (GAB) empirical models were used for the fitting of the equilibrium adsorption isotherms, finding that GAB model best fitted the experimental data. Additionally, the regeneration of the activated carbons using methanol as a regenerating agent and the single and simultaneous adsorption of a hospital wastewater effluent, fortified with the three studied pesticides have been explored.

Combined toxic effects of thiamethoxam on intestinal flora, transcriptome and physiology of Pacific white shrimp Litopenaeus vannamei.

The environmental accumulation of thiamethoxam has increasingly become a risk for the health of aquatic animals, especially crustacean species in the same phylum as the target pests. The lack of knowledge on the toxicity of thiamethoxam to crustaceans motivates our research to study the acute and chronic toxicity of decapod crustaceans Litopenaeus vannamei, exposed to thiamethoxam. A 28-day chronic toxicity test followed a 96 h acute toxicity test. Thiamethoxam induced oxidative stress and decreased growth performance in shrimp. In addition, thiamethoxam has led to a substantial imbalance of the micro-ecosystem in the intestine. The composition of the intestinal flora changed significantly, and the balance of the interaction network in genera was broken. The competitive interaction of many bacteria becomes an unstable cooperative interaction. Transcriptomic analysis showed that the numbers of up- and down-regulated differentially expressed genes (DEGs) increased in a dose-dependent manner. These DEGs were significantly enriched in pathways related to detoxification, and the expression of most detoxification genes was upregulated. DEGs related to detoxification were positively correlated with Shimia and negatively correlated with Pseudoalteromonas. This study provides evidence for the first time on the toxic effects of thiamethoxam on the growth, biochemistry, intestinal flora, and transcriptome in crustaceans.