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In the present work, composites with non-toxic metal oxides, such as TiO2 and ZnO, and a natural red clay (taua) reach in hematite were used in the photocatalytic degradation of Fenthion. The composite TiO2/Taua (0.5:1 wt. ratio) and pure TiO2 were prepared by sol-gel method while ZnO/Taua (0.5:1 wt. ratio) and pure ZnO were prepared by Pechini method. The materials were characterized by XRD, SEM, EDX, and DRS. The anatase phase was formed in both pure TiO2 and TiO2/Taua, while the hexagonal phase was formed in pure ZnO and ZnO/Taua. The bandgap energies for the two composites were narrowed compared to the respective pure oxides as consequence of the hematite (α-Fe2O3, Eg = 2.1 eV) in the red clay, reaching 2.1 eV for TiO2/Taua and 2.0 eV for ZnO/Taua, while the bandgap energies for pure TiO2 and ZnO were 3.2 and 3.0 eV, respectively. Fenthion was not degraded in the dark, but the concentration droped 20% after 180 min under visible light irradiation without photocatalyst and 60% after 210 min in the presence of the pure red clay. Both TiO2/Taua and ZnO/Taua composites were also photocatalytic active to degrade Fenthion (λ > 420 nm), with degradation of 78% (in 180 min) and 85% (in 210 min) respectively. In the optimized conditions (pH 2, 100 mg L-1 of H2O2 and 30 mg L-1 of Fenthion), the ZnO/Taua composite was the most efficient, reaching 89% degradation in up to 30 min, with Fenthion sulfoxide as the degradation product.

Nanotechnology is an emerging technology and day to day expanding its roots of knowledge to various branches of Science and fulfilling human conveniences. To manage vector populations, new tools have been emerging through nanotechnology. Nanoparticles possess peculiar toxicity mechanisms due to surface volume ratio, and this may actively contribute to their excellent larvicidal potential against Aedes aegypti mosquito. Dengue is a mosquito borne disease and making major public health issue worldwide. Aedes (Stegomyia) aegypti (Linnaeus, 1762) prefers to bread in artificial containers, and anti-larval measures with Ximenia americana L. (Olacaceae) leaf mediated silver nanoparticles (AgNPs) proves to be a potential substitute for the existing organophosphorus insecticides like temephos, malathion and fenthion etc., for mosquito control programme. Larvae were exposed to varying concentrations of plant extracts and synthesized silver nanoparticles for 24 hours. From the results, it was found that plant extracts showed moderate larvicidal effects (LC50 at 179.87 and LC90 at 376.77 ppm) but, the synthesized silver nanoparticles had found to be toxic to larvae at LC50 (0.63 ppm) and LC90 (1.20 ppm). This research highlighted that, the Ximenia americana leaf mediated AgNPs are an efficient and eco-friendly agents against Ae. aegypti mosquito, though the laboratory studies have shown the promising results, yet their efficacy in the field is to be tested for effective mosquito larval control.

In this work, a La

It is highly advantageous to devise an in vitro platform that can predict the complexity of an in vivo system. The first step of this process is the identification of a xenobiotic whose monooxygenation is carried out by two sequential enzymatic reactions. Pesticides are a good model for this type of tandem reactions since in specific cases they are initially metabolised by human flavin-containing monooxygenase 1 (hFMO1), followed by cytochrome P450 (CYP). To assess the feasibility of such an in vitro platform, hFMO1 is immobilised on glassy carbon electrodes modified with graphene oxide (GO) and cationic surfactant didecyldimethylammonium bromide (DDAB). UV-vis, contact angle and AFM measurements support the effective decoration of the GO sheets by DDAB which appear as 3 nm thick structures. hFMO1 activity on the bioelectrode versus three pesticides; fenthion, methiocarb and phorate, lead to the expected sulfoxide products with K

In the present study, a simple, rapid and efficient dispersive liquid–liquid microextraction (DLLME) coupled with spectrofluorimetry and chemometrics methods have been proposed for the preconcentration and determination of fenthion in water samples. Box–Behnken design was applied for multivariate optimization of the extraction conditions (sample pH, the volume of dispersive solvent and volume of extraction solvent). Analysis of variance was performed to study the statistical significance of the variables, their interactions and the model. Under the optimum conditions, the calibration graph was linear in the range of 5.0–110.0 ng mL-1 with the detection limit of 1.23 ng mL-1 (3Sb/m). Parallel factor analysis (PARAFAC) and partial least square (PLS) modelling were applied for the multivariate calibration of the spectrofluorimetric data. The orthogonal signal correction (OSC) was applied for preprocessing of data matrices and the prediction results of model, and the analysis results were statistically compared. The accuracy of the methods, evaluated by the root mean square error of prediction (RMSEP) for fenthion by OSC-PARAFAC and OSC-PLS models were 0.37 and 0.78, respectively. The proposed procedure could be successfully applied for the determination of fenthion in water samples.

Susceptibility status of Aedes albopictus (Skuse) sampled from residential areas in Interior, Sandakan and Tawau divisions of Sabah, Malaysia, was evaluated based on the WHOrecommended doses of organochlorine and organophosphate larvicides. To determine susceptibility status, larval bioassays were carried out and post 24-hour mortalities based on WHO resistance classifications were adopted. The results demonstrated that Ae. albopictus larvae were resistant toward 5 out of the 8 larvicides tested. Larvae from all populations were resistant against bromophos, fenitrothion, malathion, temephos and dichlorodiphenyltrichloroethane (DDT), with mortalities ranging from 0.00 to 89.33%. Dieldrin, on the other hand, could induce 100.00% mortalities in all populations, followed by fenthion and chlorpyrifos, with mortalities ranging from 97.33 to 100.00% and 81.33 to 100.00% respectively. Despite most populations exhibiting similitude in their resistance status, larvae from Sandakan exhibited the highest resistance level whereas the lowest level was observed in Keningau. In view of the inadequacy of some larvicides in controlling Ae. albopictus in this study, integrated management such as insecticide rotation or combination of interventions is warranted.

A method for the rapid determination of dichlorvos, trichlorfon, fenthion, fenthion-sulfone, fenthion-sulfoxide, fenthion-oxon, fenthion-oxon-sulfone, fenthion-oxon-sulfoxide, phoxim, propetamphos, malathion, diazinon and coumaphos 13 common organophosphorus pesticides and their metabolites poison residues in milk of cows and sheep by ultra-high-performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS) with passing type solid phase extraction(SPE) purification was developed.After centrifugation at 4 ℃, the milk was purified by passing type SPE with acetonitrile precipitating protein and determined by UPLC-MS/MS in electrospray positive ion mode(ESI+) and multi-reaction monitoring scanning(MRM), external standard method for quantitative analysis with matrix matching standard curve.The recoveries of 13 target compounds were between 81.5% and 107.5% and relative standard deviation was between 1.24% and 6.23% at three spiked levels of 5, 10, 20 μg/L. The detection limits of 13 target compounds were between 0.015 and 0.15 μg/L, and the quantitative limits were between 0.05 and 0.50 μg/L. No organophosphorus pesticide residues were detected in 20 samples of cows and sheep milk.The method has the advantages of good linear independence, low detection limit, high precision and accuracy, and can be used for daily monitoring of milk and related products.

BackgroundPesticides are widely used in agricultural production to control insect pests and regulate plant growth in China, which may result in the presence of some pesticide residues in the vegetables. However, few studies of monitoring pesticides have been conducted in Henan Province. The aim of this study was to evaluate the level of pesticide residues in commonly consumed vegetables in the regions of Henan Province.MethodsIn this study, we collected 5,576 samples of 15 different vegetables in 17 areas from Henan Province during 2020. Eight kinds of pesticides were analyzed by gas chromatography-mass spectrometry (GC-MS), including procymidone, lambda-cyhalothrin, cypermethrin, pendimethalin, isocarbophos, isazophos, fenthion and deltamethrin. The chi-square test was used to compare the detection rates of pesticide residues in different regions.ResultsOf all the pesticides above, procymidone, lambda-cyhalothrin, cypermethrin, pendimethalin and isocarbophos were detected in vegetables, the detection rates were 27.0%, 16.2%, 11.4%, 3.5%, and 1.9%, respectively. However, isazophos, fenthion, and deltamethrin were not detected. In addition, procymidone, lambda-cyhalothrin, and cypermethrin were detected in urban areas, while pendimethalin was detected in rural areas. The detection rates of cypermethrin and pendimethalin in rural were 19.8% and 5.4%, respectively, which in urban were at relatively lower levels (13.7% and 1.9%, respectively) (P < 0.05). Compared the differences of pesticide detection rates among five areas of Henan province, we found that there were statistical differences in the detection rates of procymidone, cypermethrin and lambda-cyhalothrin in different regions (all P < 0.05).ConclusionThe results have revealed that the pesticide residues are present. Higher detection rates and more types of pesticides were found in rural areas than urban areas. In addition, there were higher detection rates in Eastern Henan. The findings provided valuable information on the current pesticide residues status, which can be a reference of pesticide supervision and management.

Organophosphorus pesticides (OPs) are used in crops to eradicate pests, but are of concern to the public, attributable to their potential toxicity to human health. In the present study, a biodegradable composite film containing citrate-stabilized gold nanoparticles (AuNPs) was developed to detect pesticides. The proposed composite film has distinctive structural and functional characteristics as a colorimetric recognition indicator for detecting OPs (malathion, fenthion, dimethoate, and chlorpyrifos). The developed film was morphologically and spectroscopically characterized through electron microscopy and UV–Vis spectrometry, respectively. The spherical-shaped and monodispersed AuNPs were obtained with an average particle size of 20 nm. The aggregation of the AuNPs composite film in the presence of pesticides led to a change in color from red to blueish purple, which could be visually observed on the surface of the vegetables. Under optimum conditions, the detection limit was 2.02 μM, 1.33 μM, 2.27 μM, and 11.77 μM for malathion, fenthion, dimethoate, and chlorpyrifos, respectively. The developed films demonstrated good biodegradability, and excellent storage stability, sensitivity and selectivity, with recovery values ranging from 99.60 to 103.68%, and relative standard deviation (RSD) values from 0.56 to 5.76%. The findings indicate a sensitive and selective sensing biodegradable colorimetric film, which is eco-friendly, biodegradable, considered to have promising low-costs, and a renewable source material for detecting pesticide residues.

In this study, magnetic Fe3O4@SiO2@β-cyclodextrin copolymerized microparticles were synthesized and applied for the extraction of methyl parathion and fenthion in lettuce samples followed by HPLC-UV detection. The magnetic β-cyclodextrin copolymerized microparticles were prepared by dispersion polymerization with acryloyl β-cyclodextrin as the functional monomer and ethylene glycol dimethyacrylate as the crosslinker. The composite magnetic microparticles were characterized by Fourier transform infrared spectroscopy, X-ray diffraction, magnetic measurement, and thermogravimetric analysis, and used as the adsorbent of magnetic solid-phase extraction (MSPE) for methyl parathion and fenthion. The extraction conditions including sample pH and ionic strength, desorption solvent type and volume, and adsorption and desorption times were optimized. Under the optimal extraction conditions, an MSPE-HPLC-UV method was developed for the detection of methyl parathion and fenthion in lettuce. Wide linear ranges of 1.0-200 μg kg-1 (R2 = 0.9998) for methyl parathion and 1.5-200 μg kg-1 (R2 = 0.9978) for fenthion were obtained and the limits of detection were 0.3 μg kg-1 for methyl parathion and 0.5 μg kg-1 for fenthion in lettuce, respectively. The proposed method was applied for the determination of methyl parathion and fenthion in lettuce with satisfactory recoveries between 89.2-101.2%, and relative standard deviations were less than 9.1%. Thus, the MSPE-HPLC-UV method has high accuracy and sensitivity for the analysis of methyl parathion and fenthion in lettuce samples.

Metal-organic frameworks (MOFs) have great potential to remove pesticide residues. However, the lack of affinity between the materials and target and the process of trivial sample preparation resulted in limited removal efficiency. Here, we report a one-pot method for the fast preparation of NH

In the present study, a molecularly imprinted solid-phase extraction (MISPE) technique coupled with high-performance liquid chromatography was applied for selective extraction and recognition of fe...

In this paper, a green proline choline ionic liquid ([Ch][Pro])-modified magnetic graphene oxide was used as the solid-phase extractant (Fe3O4@SiO2@GO@[Ch][Pro]), which was characterized by FIR and hysteresis loops. A novel method for the determination of fenthion by magnetic solid-phase extraction with HPLC was established. Factors affecting extraction and elution performance were investigated, such as the amount of extractant, pH of the solution, the time and temperature of extraction and elution. Under the best conditions, a good linearity (R2 = 0.9987) equation was obtained with the concentration range 0.02–10 μg mL−1. This method has been successfully applied to the determination of fenthion in apple samples and water samples.

The main objective of this study was to assess the pesticide removal efficiency of chitosan in grape juice during clarification. The grape juice was spiked with six selected pesticides (chlorpyrifos, ethion, diazinon, fenitrothion, fenthion and phorate) and clarified with chitosan at different concentrations and at three different incubation times (1, 2 and 4 h). The effect of chitosan on the level of pesticides in grape juice during clarification was quantified using modified QuEChERS method with gas chromatography with tandem mass spectrometry (GC-MS/MS). The method for pesticide quantification has been validated. The maximum removal was obtained for chlorpyrifos (98%) and ethion (97%) at 0.5% of chitosan concentration for 1 h incubation followed by phorate (96%), fenthion (95%), fenitrothion (94%) and diazinon (86%) at 1% of chitosan concentration for 2 h incubation time. The juice was clarified with other clarifying agents such as activated carbon, gelatin, casein and bentonite and its pesticide removal efficiency was compared with chitosan. The pesticide removal level could be correlated with the properties of selected pesticides and clarifying agents. The results indicated that the chitosan can act as an effective pesticide scavenger and it leads to the potential application of chitosan in fruit juice clarification.

The production of Nile tilapia (Oreochromis niloticus) in Brazil exhibits the highest growth rate in the world and represents approximately 45% of the total fish production. The objective of the present study was to assess the risk for human health due the consumption of tilapia farmed in net cages in eight aquaculture parks in Brazil. The concentrations of pesticides (40 compounds), metals (Mn, Ni, Zn, Cd, Pb, and Sn), arsenic, and cyanotoxins (microcystins) were evaluated in 16 fish from each park. Among analyzed pesticides, pyraclostrobin (0.18–0.32 mg/kg) and fenthion (0.0026–0.0037 mg/kg) exhibited values above the limit of quantification in the tilapia from Aracoiaba, Castanhao, and Ilha Solteira. The highest concentrations of As (0.44 μg/g) in fish tissues were found in Juara, Mn (0.21 μg/g) in Castanhao, and Zi (11.5 μg/g) were found in Tres Marias. Furnas and Linhares exhibited the lowest metal concentrations. The estimated daily intake of muscle by the average Brazilian with 70 kg body weight is below the reference dose for all studied metals in all parks. Total free microcystins showed an accumulation pattern (muscle < gill < liver). The highest concentration in muscle was found in Castanhao (1043 μg/kg) samples. The results showed that fish exhibited metal, As, and pesticide tolerable daily intake (TDI) below the limit and pose low risk for human consumption. Otherwise, TDI for microcystins in fish of all studied parks was above the maximum level recommended by the World Health Organization, indicating that there exists a toxicity risk of fish consumption.

Several organophosphorus compounds such as organophosphate pesticides (OPPs) and trialkylphosphates (TAPs) are suspected to inhibit cholinesterase activities, to affect endocrine systems or to possibly be carcinogenic. To evaluate their adverse effects on health with chronic exposure in the general population, especially in children, we measured the household exposure to OPPs and TAPs by Japanese children via all exposure pathways and the contribution of indoor air quality. First-morning void urine was collected from subjects aged 6 to 15 years (n = 132), and airborne organophosphorus compounds were sampled in the subject's bedroom for 24 h. Airborne levels of nine OPPs and three TAPs and their urinary metabolites were determined. No significant correlations were detected for any compounds between their airborne concentrations and the urinary excretion amounts of their corresponding metabolites. The estimated daily intakes were as follows (median, μg/kg b.w./d): chlorpyrifos, 0.042; diazinon, 0.067; tri-n-butylphosphate, 0.094. The 95th percentiles of the intakes for fenthion, fenitrothion and the above three compounds did not exceed their reference limit values, although one subject had a daily intake of tri-n-butylphosphate that was about twice its reference limit value. The concentration levels of the urinary metabolite of tri-n-butylphosphate in our subjects tended to be higher than those for children in many other countries. The fractions of the amounts absorbed by inhalation to the amounts absorbed via all of the exposure pathways was only 2.3 % (median) for tri-n-butylphosphate. Inhalation did not seem to contribute very much as an absorption pathway of the organophosphorus compounds in these Japanese children while they were at home. The exposure amounts of OPPs were not suggested to be high enough to adversely affect the health of these children at present on the basis of their daily intakes compared to their reference limit values.

Out of the five isoforms of human flavin-containing monooxygenase (hFMO), FMO1 and FMO3 are the most relevant to Phase I drug metabolism. They are involved in the oxygenation of xenobiotics including drugs and pesticides using NADPH and FAD as cofactors. Majority of the characterization of these enzymes has involved hFMO3, where intermediates of its catalytic cycle have been described. On the other hand, research efforts have so far failed in capturing the same key intermediate that is responsible for the monooxygenation activity of hFMO1. In this work we demonstrate spectrophotometrically the formation of a highly stable C4a-hydroperoxyflavin intermediate of hFMO1 upon reduction by NADPH and in the presence of O2. The measured half-life of this flavin intermediate revealed it to be stable and not fully re-oxidized even after 30 min at 15 °C in the absence of substrate, the highest stability ever observed for a human FMO. In addition, the uncoupling reactions of hFMO1 show that this enzyme is

In this study, magnetic Fe3O4@SiO2@β-cyclodextrin copolymerized microparticles were synthesized and applied for the extraction of methyl parathion and fenthion in lettuce samples followed by HPLC-UV detection. The magnetic β-cyclodextrin copolymerized microparticles were prepared by dispersion polymerization with acryloyl β-cyclodextrin as the functional monomer and ethylene glycol dimethyacrylate as the crosslinker. The composite magnetic microparticles were characterized by Fourier transform infrared spectroscopy, X-ray diffraction, magnetic measurement, and thermogravimetric analysis, and used as the adsorbent of magnetic solid-phase extraction (MSPE) for methyl parathion and fenthion. The extraction conditions including sample pH and ionic strength, desorption solvent type and volume, and adsorption and desorption times were optimized. Under the optimal extraction conditions, an MSPE-HPLC-UV method was developed for the detection of methyl parathion and fenthion in lettuce. Wide linear ranges of 1.0-200 μg kg-1 (R2 = 0.9998) for methyl parathion and 1.5-200 μg kg-1 (R2 = 0.9978) for fenthion were obtained and the limits of detection were 0.3 μg kg-1 for methyl parathion and 0.5 μg kg-1 for fenthion in lettuce, respectively. The proposed method was applied for the determination of methyl parathion and fenthion in lettuce with satisfactory recoveries between 89.2-101.2%, and relative standard deviations were less than 9.1%. Thus, the MSPE-HPLC-UV method has high accuracy and sensitivity for the analysis of methyl parathion and fenthion in lettuce samples.

Plasmonic nanoparticles offer attractive benefits for the detection of environmental contaminants due to their high extinction coefficients and unique optical properties. Excess use of OP pesticides has been found to have adverse effects on human health and the environment. Here, we demonstrate the use of plasmonic silver (Ag), gold (Au) and bimetallic silver-gold (Ag-Au) nanoparticles (NPs) to detect and distinguish between organophosphorus (OP) pesticides. The NPs were found to detect the thion pesticides: ethion, parathion, malathion, and fenthion) in real time. In each case, the interaction of the pesticides with the plasmonic NPs were found to result in wavelength shifts of the localized surface plasmon resonance (LSPR) accompanied by color changes. The wavelength shifts were characteristic of the pesticide structure and concentration. The interaction between the sensors and the pesticide was a result of the soft metal surface binding to the soft sulfur atom of the pesticide. Similarly, oxon pesticides showed no effect on the LSPR of the NPs. The three plasmonic NPs showed limits of detections (LOD) in ppm range for all pesticides under real-time analysis. The LOD of Ag NPs with ethion, fenthion, malathion, and parathion were 9 ppm, 11 ppm, 18 ppm, and 44 ppm, respectively. The LOD of Au NPs with ethion, fenthion, malathion, parathion were 58 ppm, 53 ppm, 139 ppm, and 3203 ppm, respectively. Ag-Au NPs with ethion, fenthion, malathion, and parathion showed LOD values of 228 ppm, 231 ppm, 1189 ppm, and 1835 ppm, respectively. The ability of the plasmonic NPs to detect the selected pesticides in natural environments was tested under simulated natural conditions in the presence of dissolved organic matter (DOM). Steep gradients in the sedimentation plots revealed that the time dependent interaction of each OP pesticide with the NP surface was accompanied by a considerable change in the LSPR indicative of colloidal destabilization over time. All pesticides showed nearly the same trend in their sedimentation with the plasmonic NPs. The stability of the nanoparticles in the colloidal medium was described by classical DLVO theory, which showed that the net interaction was attractive.

Following the loss of two key pesticides, dimethoate and fenthion, producers and regulators need to develop new fruit fly management options. A systems approach is a likely measure in the post dimethoate and fenthion era. The risk of fruit fly can be mitigated at the regional, district and farm level. Some measures such as awareness and exclusion are common across all three levels. Pest control measures will be based on an understanding of climate, biology and pesticides. In this present paper, 28 different risk mitigation options that can be used in a systems approach in Australia are discussed.

This study was conducted to monitor the susceptibility status of Aedes aegypti (Linnaeus) larvae in the Sunda Islands of Indonesia against various organophosphates and organochlorines. Larval bioassay was performed in accordance with the World Health Organization standard protocol. Field-collected and reference strains of Ae. aegypti larvae were tested against diagnostic doses of eight larvicides belonging to organophosphates and organochlorines, namely bromophos (0.050 mg/liter), chlopyrifos (0.002 mg/liter), fenitrothion (0.020 mg/liter), fenthion (0.025 mg/liter), malathion (0.125 mg/liter), temephos (0.012 mg/liter), DDT (0.012 mg/liter), and dieldrin (0.025 mg/liter). Mortality rates of larvae were recorded at 24-h posttreatment. This study showed that Ae. aegypti larvae from Padang, Samarinda, Manggarai Barat, and South Central Timor were susceptible to both fenitrothion and dieldrin (mortality rates ≥ 98%). About 6 out of 10 field strains of Ae. aegypti larvae were resistant (

In this study, we reported the occurrence of eight organophosphorus pesticides (OPPs) in the East China Sea. Forty samples were collected and analysed with a high volume solid phase extraction method (Hi-throat/Hi-volume SPE) in the early summer of 2020. All the target OPPs were detected in the surface water at one or more stations in the East China Sea, and the concentrations of ΣOPPs were in the range 0.0775–3.09 ng/L (mean: 0.862 ± 0.624 ng/L). Terbufos sulfone and fenthion were the main pollutants in this area, probably resulting from pesticide use in China and other countries. The off-shore input from coastal regions was suggested to be a major source of OPP pollution in the East China Sea, and the movement of ocean currents played an important role in their transportation because around 0.86 t OPPs passed through the Tsushima Strait from the East China Sea each month. An ecological risk assessment showed that these OPPs presented a high risk to species in the East China Sea, whereas they posed no health risk to humans under both the median and high exposure scenario.

The aim of this study was to investigate reported cases of honeybee mortality incidents and the potential association to pesticide exposure and to their metabolites. The same honeybee samples were also assessed for Varroa mites, and Nosema microsporidia provoked infections to provide an integrated picture of all observable stressors that may impact bees' survival. Thus, honeybee samples from different areas of Greece (2014–2018) were analyzed for the presence of pesticide residues and metabolites. In this context, an existing LC-ESI-QqQ-MS multiresidue method of analytes of different chemical classes such as neonicotinoids, organophosphates, triazoles, carbamates, was enriched with additional active substances, developed and validated. A complementary GC-EI-QqQ-MS method was also exploited for the same scope covering pyrethroid compounds. Both methods monitored more than 150 active substances and metabolites and presented acceptable linearity over the ranges assayed. The calculated recoveries ranged from 65 to 120% for the three concentration levels, while the precision (RSD%) values ranged between 4 and 15%. Therefore, this approach proved sufficient to act as a monitoring tool for the determination of pesticide residues in cases of suspected honeybee poisoning incidents. From the analysis of 320 samples, the presence of 70 active substances and metabolites was confirmed with concentrations varying from 1.4 ng/g to 166 μg/g. Predominant detections were the acaricide coumaphos, several neonicotinoids exemplified by clothianidin, organophosporous compounds dimethoate and chlorpyrifos, and some pyrethroids. Metabolites of imidacloprid, chlorpyrifos, coumaphos, acetamiprid, fenthion and amitraz were also identified. Concerning Nosema and Varroa they were identified in 27 and 22% of samples examined, respectively, verifying their prevalence and coexistence with pesticides and their metabolites in honeybees.

Protein carbonylation is an irreversible oxidative modification that has been associated with a decrease in the quality and nutritional value of products of animal origin. Generally, the carbonylation is attributed to processes of slaughter, processing, and cold storage of products. However, in vitro studies have shown that fluoroquinolone and organophosphate pesticides residues at their maximum residue limits (MRL) can promote carbonylation of animal proteins. Though, this effect on in vivo conditions has not yet been evaluated. Thus, Eisenia fetida was chosen as a model to assay their oxidant effect. For this, adult earthworms were exposed to artificial soil contaminated with ciprofloxacin, danofloxacin, fenthion, and diazinon at three concentrations (0.5, 1.0, and 1.5 MRL) for 28 days. Then, these were purged and sacrificed to obtain the muscle region between the anus and preclitellum. The muscle samples were cold macerated to obtain muscle proteins, which were used for protein quantification, determination of carbonyl levels, and carbonyl protein profiles employing Bradford, Dot-blot, and Western blot assays, respectively. The results showed that at each concentration assayed, all pollutants induced significant carbonylation respect to control (p 0.05). Additionally, mass spectrometry-based analysis (MALDI-TOF/TOF) identified actin as the protein most susceptible to carbonylation promoted by these substances. Therefore, these findings show for the first time the oxidant power of fluoroquinolones and organophosphates pesticides at MRLs concentrations on muscle proteins under in vivo conditions. Fact causes concern due to the homology of muscle proteins in eukaryotes, which allow to hypothesize that this effect could also be experienced by proteins from food-producing animals in the same way that observed in in vitro studies.

A magnetic material, F e 3 O 4 @ Z r O 2 , was used to enrich an organophosphorus pesticide, fenthion. After enrichment the F e 3 O 4 @ Z r O 2 was treated with NaOH to elute and hydrolyze fenthion. The hydrolysis products, orthophosphate ions, combine to molybdate ions to yield molybdophosphoric acid, which was further reduced with S n C l 2 to obtain a blue phosphatemolybdate. The content of orthophosphate ions as well as fenthion can be determined through the spectrophotometric method. Adsorption and elution conditions were optimized to obtain an enrichment factor of 12.5. The proposed composite method was successfully used to analyze the fenthion residues on the skin of cucumber and apple samples. The limit of detection was as low as 0.037 mg/Kg, which was close to that of the gas chromatography–mass spectrometer method. The method was simple, rapid, and economic, suitable for the rapid screen of fenthion and the other organophosphorus pesticide in mass samples.

Short-term biomarkers of toxicity have an increasingly important role in the screening and prioritization of new chemicals. In this study, we examined early indicators of liver toxicity for three reference organophosphate (OP) chemicals, which are among the most widely used insecticides in the world. The OP methidathion was previously shown to increase the incidence of liver toxicity, including hepatocellular tumors, in male mice. To provide insights into the adverse outcome pathway (AOP) that underlies these tumors, effects of methidathion in the male mouse liver were examined after 7 and 28 day exposures and compared to those of two other OPs that either do not increase (fenthion) or possibly suppress liver cancer (parathion) in mice. None of the chemicals caused increases in liver weight/body weight or histopathological changes in the liver. Parathion decreased liver cell proliferation after 7 and 28 days while the other chemicals had no effects. There was no evidence for hepatotoxicity in any of the treatment groups. Full-genome microarray analysis of the livers from the 7 and 28 day treatments demonstrated that methidathion and fenthion regulated a large number of overlapping genes, while parathion regulated a unique set of genes. Examination of cytochrome P450 enzyme activities and use of predictive gene expression biomarkers found no consistent evidence for activation of AhR, CAR, PXR, or PPARα. Parathion suppressed the male-specific gene expression pattern through STAT5b, similar to genetic and dietary conditions that decrease liver tumor incidence in mice. Overall, these findings indicate that methidathion causes liver cancer by a mechanism that does not involve common mechanisms of liver cancer induction.

Fenthion an active compound contained in EC 500 lebaycid pesticides that are toxic. To reduce the level of toxicity will be degradation in sonolysis, ozonolysis and sonozolysis with the addition of TiO2-anatase. Degradation results in sonolysis, ozonolysis and sonozolysis measured by UV-Vis spectrophotometer at wavelength of 400-600 nm. From the research that has been made degradation result fenthion 6 mg/L in sonolysis without addition of catalyst of 37.5% and with the addition of TiO2-anatase catalyst obtained for 65.12% of degradation for 60 minutes. In ozonolysis at the same time obtained percent degradation of 39.77% without the addition of catalyst and 81% with the addition of TiO2-anatase catalyst. Percent degradation fenthion compound without the addition of TiO2-anatase catalyst after a 60-minute sonozolysis obtained at 91.7%.

An acryloyl β-cyclodextrin-silica hybrid monolithic column for pipette tip solid-phase extraction and high-performance liquid chromatography determination of methyl parathion and fenthion has been prepared through a sol-gel polymerization method. The synthesis conditions, including the volume of cross-linker and the ratio of inorganic solution to organic solution, were optimized. The prepared monolithic column was characterized by thermogravimetric analysis, scanning electron microscopy, and Fourier transform infrared spectroscopy. The eluent type, volume and flow rate, sample volume, flow rate, acidity, and ionic strength were optimized in detail. Under the optimized conditions, a simple and sensitive pipette tip solid-phase extraction with high-performance liquid chromatography method was developed for the determination of methyl parathion and fenthion in lettuce. The method yielded a linear calibration curve in the concentration ranges of 15-400 μg/kg for methyl parathion and 20-400 μg/kg for fenthion with correlation coefficients of above 0.9957. The limits of detection were 4.5 μg/kg for methyl parathion and 6.0 μg/kg for fenthion, respectively. The recoveries of methyl parathion and fenthion spiked in lettuce ranged from 96.0 to 104.2% with relative standard deviations less than 8.4%.

Dynamic surface-enhanced Raman spectroscopy (D-SERS) based on the state change of the substrate not only significantly enhances but also provides a highly reproducible Raman signal. Hence, we develop a fast and accurate method for the detection of fenthion on fruit and vegetable peel using D-SERS and random forests (RF) with variable selection. With uniform Ag nanoparticles, the dynamic spectra of fenthion solution at different concentrations were obtained using D-SERS, and fenthion solution greater than or equal to 0.05mg/L can be detected. Then, the quantitative analysis models of fenthion were developed by RF with variable selection for spectra of different range. The model of best performance is developed by RF and spectra of characteristic range with higher RF importance (top 40%), and the root mean square error of cross-validation is 0.0101mg/L. Moreover, the fenthion residue of tomato, pear, and cabbage peel were extracted by a swab dipped in ethanol and analyzed using the above method to further validate the practical effect. Compared to gas chromatography, the maximal relative deviation is below 12.5%, and the predicted recovery is between 87.5% and 112.5%. Accordingly, D-SERS and RF with variable selection can realize the fast, simple, ultrasensitive, and accurate analysis of fenthion residue on fruit and vegetable peel.

The present study aims to investigate the susceptibility status of Aedes albopictus (Skuse) collected from residential areas in Sabah, Malaysia towards eight WHO-recommended dosages of larvicides representing the classes of organophosphates and organochlorines. Field and reference strains of Ae. albopictus larvae were bioassayed in accordance to WHO standard methods using diagnostic dosages of bromophos, malathion, fenthion, fenitrothion, temephos, chlorpyrifos, dichlorodiphenyltrichloroethane (DDT), and dieldrin. The results revealed that Ae. albopictus was resistant (mortality < 90%) towards malathion, temephos, and DDT. In addition, most of the Ae. albopictus strains exhibited a wide range of susceptibilities against bromophos, with mortality ranged from 49.33 to 93.33%. On the contrary, only dieldrin was able to induce 100% mortality against all strains of Ae. albopictus. Tolerance to fenitrothion, fenthion, and chlorpyrifos, with mortality ranging from 81.33 to 97.33%, was also observed in this study.

The endocrine-disrupting activities of various environmental chemicals are metabolically activated. For example, diphenyls, styrene oligomers, chalcones, trans-stilbene and 2-nitrofluorene are not estrogens, but after incubation with liver microsomes, their metabolites show estrogenic activities. Thus, these chemicals are estrogenically activated by the cytochrome P450 system. In contrast, the antiandrogenic activity of fenthion, an organophosphorus insecticide, is abolished after metabolism to sulfoxide and sulfone derivatives. Structural requirements of twenty bisphenol A related compounds, as well as various benzophenones, for estrogenic and antiandrogenic activities have been investigated. The estrogenic and antiandrogenic activities of Benzophenone 3, a representative UV absorbant, are activated by oxidative metabolism. Parabens (used as antimicrobial agents) exhibit estrogenic activity, and their potency shows a bell-shaped curve between C1 (methylparaben) and C12 (dodecylparaben) parabens. The AhR ligand activity of indirubin is decreased by metabolism. Polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDE) are activated by hydroxylation to show estrogenic and thyroid hormone-disrupting activities. Halogen adjacent to a hydroxyl group is essential for thyroid hormone-disrupting activity. Tetrabromobisphenol A, tetrachlorobisphenol A and tetramethylbisphenol A also exhibit thyroid hormone-disrupting activity. Amphibian metamorphosis of tadpoles to frogs is affected by hydroxylated PCB, hydroxylated PBDE and bisphenol A derivatives. These chemicals suppress thyroid hormone-dependent metamorphosis, acting as antagonists of thyroid hormone. Thus, metabolic modification can have a dramatic impact on the endocrine-disrupting activities of environmental chemicals.

Foi avaliada a eficácia de produtos ectoparasiticidas contra larvas de Aedes aegypti. Os princípios ativos fluazuron 2,5 g, cipermetrina 150 g, flumetrina 1 g, propoxur 1 g, deltametrina 25 g, clorpirifós 30 g, cipermetrina 15 g, fenthion 15 g, diazinon técnico estabilizado 40 g, fipronil 2,5%, triclorfone 97 g, coumafós 3 g, propoxur 2 g, fentione 15 g e amitraz 12,5% foram adquiridos comercialmente e preparados conforme recomendações dos fabricantes. Os produtos foram distribuídos em recipientes individuais contendo larvas de A. aegypti em ambiente controlado. A inspeção da viabilidade larval foi verificada durante 24 horas. Os produtos foram aplicados nos locais de coleta das larvas (criadouros dos mosquitos), vistoriados diariamente por um mês. Foi observado que 100% das larvas morreram em até 60 minutos, tanto nos recipientes monitorados em laboratório como no meio ambiente. Nas áreas em que foi realizada a pulverização com os inseticidas supramencionados, não foi verificada a presença de larvas por um período de até 30 dias. Concluiu-se que produtos comumente utilizados em animais como ectoparasiticidas foram eficazes contra larvas de A. aegypti, podendo ser utilizados para o controle desse importante vetor, caso tal utilização seja analisada e regulamentada pelos órgãos oficiais do país.

The objective of this study was to evaluate the capability of the bacteria Bacillus safensis strain FO-36bT isolated from pesticide-polluted soil in degrading fenthion and temphos in mineral salt media (MSM). Fenthion and temphos were incubated with the isolated bacteria. Samples were drawn at 0, 3, 7, 14, and 30 days to analyze residual fenthion and temphos content with gas chromatography (GC) and high-performance liquid chromatography (HPLC), respectively. The loss of the initial pesticide concentration (400 mg/L) over time was determined and used to compute the half-lives using a biphasic model. Gas chromatography-mass spectrometry (GC-MS) was used to identify the major metabolites as well as to re-confirm the identity of starting material (fenthion). The results showed that the bacterium was still viable at the end of each incubation period. The biodegradation of fenthion and temphos followed a biphasic model. The half-lives of fenthion in the first and in the second phase were 0.29 and 3.69 days, respectively, whereas the corresponding values for temphos were 0.11 and 1.15 days. Only one metabolite "iso-fenthion" (O, S-dimethyl O-[3-methyl-4-(methylthio)phenyl] phosphorothioate) was detected in fenthion culture, while no metabolites were detected in temphos culture. Based on the half-lives, this bacterium was able to degrade temphos at a faster rate than fenthion. Key words: Biodegradation, fenthion, temphos, bacteria, pesticides-contaminated soil, Sudan.

This study aimed to describe the relationship between viral infection in Nilaparvata lugens (Stal), the brown planthopper (BPH), and different insecticide susceptibilities. BPH-resistant strains were selected using fenthion (an organophosphate) or etofenprox (a pyrethroid); a susceptible strain was used as the baseline colony before insecticide selection. All strains were infected with rice ragged stunt virus (RRSV) or rice grassy stunt virus (RGSV), after which the activities of three detoxification enzymes, cytochrome-P450-monooxygenase (P450), glutathione S-transferase (GST), and carboxylesterase (CE), were compared. Males of the strains selected for both insecticides showed high P450 and GST-CDNB activities. The activity of all enzymes was higher in males than in females, as a whole. However, males of the susceptible strain infected with RRSV showed decreased CE and GST-CDNB activities. BPH with low susceptibility to etofenprox showed a marked increase in P450 activity after RRSV infection; the GST-CDNB activity of females in the insecticide-resistant strain increased. RGSV infection induced high CE and P450 activities in etofenprox-selected females. The RRSV infection rate, but not the RGSV, decreased in etofenprox-selected strains.

A simple method for determining 33 pesticides with a wide polarity range (logKow 0.6-4.5) in aquatic products was developed based on LC-MS/MS. The target analytes included three types of widely used pesticides: insecticides, fungicides and herbicides. Based on the optimization of ultrasonic assisted extraction and GPC clean-up procedures, the matrix effect, extraction recoveries and LOD were improved distinctively. LOQ of this method was below 0.5ng/g for all pesticides, which is superior to values in the literature, and the matrix effect was reduced effectively (-14.7% to 7.5%). The method was successfully applied to investigate the pesticide residue levels of twenty-five samples including seven common kinds of fishes from Northeast China. The results showed that all targeted pesticides were present in the fish samples; however, their levels were low, except for atrazine, linuron, ethoprophos, tetrachlorvinphos, acetochlor and fenthion. Atrazine and linuron caught our attention because the concentrations of atrazine in fish samples from Liaoning province were in the range of 0.5-8ng/g (w/w) with mean concentration of 2.3ng/g, which were far above those of other pesticides. The levels of linuron were in the range of 0.6-6ng/g (mean concentration 2.8ng/g), which were the highest among all targeted pesticides in the Inner Mongolia. This is the first systematic investigation on the characteristics and levels of these pesticides in aquatic products from northeast China. Considering their toxicity and bioaccumulation, the potential risk of atrazine and linuron from consuming aquatic products should be paid more attention.

Development of an acute oral toxicity test with a terrestrial-phase amphibian was considered necessary to remove the uncertainty within the field of agrochemical risk assessments. The bullfrog (Lithobates catesbeianus) was selected for use as it is a representative of the family Ranidae and historically this species has been used as an amphibian test model species. Prior to definitive study, oral gavage methods were developed with fenthion and tetraethyl pyrophosphate. Dimethoate and malathion were subsequently tested with both male and female juvenile bullfrogs in comprehensive acute oral median lethal dose (LD50) studies. Juvenile bullfrogs were administered a single dose of the test article via oral gavage of a single gelatin capsule of dimethoate technical (dimethoate) or neat liquid Fyfanon® Technical (synonym malathion), returned to their respective aquaria, and monitored for survival for 14 d. The primary endpoint was mortality, whereas behavioral responses, food consumption, body weight, and snout-vent length (SVL) were used to evaluate indications of sublethal toxicity (secondary endpoints). Acute oral LD50 values (95% fiducial interval) for dimethoate were 1459 (1176-1810, males) and 1528 (1275-1831, females), and for malathion they were 1829 (1480-2259, males) and 1672 (1280-2183, females) mg active substance/kg body weight, respectively. Based on the results of these studies, the methodology for the acute oral gavage administration of test items to terrestrial-phase amphibians was demonstrated as being a practical method of providing data for risk assessments. Environ Toxicol Chem 2018;37:436-450. © 2017 SETAC.

In this paper, a helical copper wire, coated with copper-benzene-1,4-dicarboxylic acid metal-organic framework (Cu-BDC) was used as a sorbent for stir-bar sorptive extraction of fenthion from water and fruit samples. The homogenous coating was fabricated through two simple and fast steps. The chemical conversion of copper substrate to copper hydroxide nanotubes (Cu(OH)2 NTs) was performed in an alkaline solution and then Cu-BDC was formed through a neutralization reaction. Corona discharge ion mobility spectrometry in positive mode was applied for the detection of fenthion. To improve the sensitivity of the method, some synthesis and extraction parameters affecting the extraction efficiency such as benzene-1,4-dicarboxylic acid concentration, ionic strength, sample pH, stirring rate, extraction temperature, and extraction time were investigated. The linear dynamic range between 0.5 and 80 μg L-1 and detection limit of 0.1 μg L-1 were obtained under optimal conditions. The intra- and inter-day relative standard deviations were less than 6.4 and 8.6%, respectively. The applicability of the method was examined for the analysis of different samples (i.e., well water, agricultural wastewater, and orange). The recovery for the determination of fenthion in spiked samples varied from 88 to 111%.

Fenthion is a widely used organophosphorus pesticide in agriculture that induces different cytotoxic effects, including male reproductive toxicity. The present work aimed to study the ameliorative effects of curcumin, a potential therapeutic agent against several chronic diseases, on reproductive toxicity induced by the organophosphate insecticide fenthion. Forty adult male albino rats were divided into four groups. The control group received distilled water. The curcumin group was administered curcumin at a dose of 100 mg kg−1 body weight. The fenthion group was administered fenthion at a dose of 0.001 mg kg−1. The fenthion/curcumin group was administered fenthion and curcumin together at the same doses. After four weeks of daily oral administration, the animals were sacrificed and their testes were excised. Specimens were processed for histopatholological and immunohistochemical investigations. Light and electron microscopic analysis visualised dramatic degenerative changes in seminiferous tubules as indicated by atrophy, necrosis, vacuolation and decreased number of spermatogenic cells. Moreover, the fenthion group showed a significant reduction in the proliferating cell nuclear antigen (PCNA)-immunoreactivity. Decreased PCNA-immunoreactivity reflected the depletion in the proliferation rate of spermatogenic cells and suggesting arrested spermatogenesis. Curcumin administration to fenthion-treated rats revealed mild degenerative changes with partial improvement of active spermatogenesis. In conclusion, these data may confirm the cytoprotective potency of curcumin against fenthion-induced cyto-toxicity.Keywords: curcumin, fenthion, histology, PCNA, testis, ultrastructure

The susceptibility values for field-collected (BG-BG) and laboratory (KS-BG) strains of German cockroaches (BS-BG), Blattella germanica (L.) to five synthetic pyrethroid and three organophosphate insecticides were assessed by topical application. Both KS-BG and BS-BG strains demonstrated the highest levels of susceptibility to deltamethrin with LD50 values of 0.0035 μg/female and 1.5744 μg/female, respectively. The KS-BG strain demonstrated the lowest susceptibility level to fenthion with an LD50 value of 0.0698 μg/female, while the BS-BG field population showed the lowest susceptibility to bifenthrin with 4.6811 μg/female. The BS-BG field population showed resistance levels of 50 to 640 fold higher against the eight pesticides evaluated compared to the KS-BG strain. The resistance ratios (RR) of the eight pesticides were compared using populations of B. germanica that were collected from the same locality during 2007 and 2014. The field population of B. germanica collected during 2014 demonstrated significantly high resistance to an organophosphates and all pyrethroids when compared with those collected during 2007, but RR values were

Fenthion (organophosphate) was used in Australia to target adults, eggs and larvae of Mediterranean fruit fly (Medfly), Ceratitis capitata Wiedmann (Diptera: Tephritidae) in deciduous fruits. With its removal from use in 2015, clothianidin and thiacloprid (neonicotinoids) were evaluated for any adulticide, ovicide or larvicide (eggs, larvae) activity against Medfly in a series of laboratory and field-cage experiments in peach and nectarine. We included fenthion in all experiments as a positive control. As an adulticide, fenthion had the greatest residual toxicity on fruit, with 7 d old residues killing 44% of adults within 48 h compared to thiacloprid (17%) and clothianidin (30%). When applied as a larvicide to naturally infested peaches, none of the insecticides was 100% effective, though fewest pupae (1.18 ± 0.19 pupae/fruit) (indirect measurement of larval survival) were produced when treated with fenthion, followed by clothianidin (3.40 ± 0.33 pupae/fruit) and thiacloprid (6.88 ± 0.34 pupae/fruit); with 11.35 ± 0.30 pupae/fruit in control (water). In peaches treated 48 h post-infestation, fenthion was most effective in reducing numbers of pupae and adult emergence and with higher percentage of deformed adults, with thiacloprid=clothianidin. In nectarines treated 48 h post-infestation, fenthion was most effective in reducing numbers of pupae and adult emergence as well as with higher percentage of deformed adults, followed by clothianidin. Insecticides were least effective when applied as a preventative 24 h or 7 d prior to infestation, with fenthion more effective than clothianidin. Whilst our study shows that neither clothianidin nor thiacloprid are equivalent to fenthion, they are acceptable substitutes to growers for use for Medfly in deciduous fruits given that fenthion is no longer available to growers in Australia. We recommend that growers incorporate other controls to target the adult stage rather than rely only on new insecticides.

Adsorption and biodegradation processes for four organophosphate pesticides (chlorpyrifos, diazinon, fenthion, dichlorvos) in wetlands and agricultural drains in Meric-Ergene Basin, Turkey have been investigated. Koc (organic carbon normalized partition coefficient) values for all pesticides except diazinon were higher in more aromatic Pamuklu Drain sediments, indicating the possible influence of aromaticity on the extent of adsorption. The average half-lives of pesticides in Gala Lake sediments and Pamuklu agricultural drain sediments ranged from 2.25 to 69.31 days with chlorpyrifos exhibiting the slowest biotransformation rate and dichlorvos having the fastest biotransformation rate. The presence of humic substances and hydroperiod of wetlands have been identified as possible factors that affected the behavior of organophosphate pesticides in this study. The results from this study provide insight into the constructed wetland design offered for the mitigation of organophosphate pesticides in the basin.

RATIONALE Dermal exposure to pesticides may cause severe intoxication and even result in a fatal outcome. To expedite rescue in the emergency department, it is mandatory to develop a point-of-care analytical method for immediate identification of pesticides on the skin of exposed personnel, and to perform immediate dermal decontamination to prevent further harm and optimize the chance for full clinical recovery. METHODS Four of the most commonly used highly toxic pesticides that contaminate the skin were rapidly characterized by thermal desorption electrospray ionization mass spectrometry. The technique was also applied to confirm the completeness of pesticide decontamination from the skin. Pesticide sampling, desorption, ionization, and detection altogether took less than 30 s. In addition, different fabrics of protective garments worn by farmers were assessed with this efficient ambient mass spectrometric technique for their protective capabilities against dermal exposure to pesticides, and scanning electron microscopy was used to observe their different microstructures. The decontaminating efficacies of different cleansing agents for these skin contaminants were also evaluated by this technical platform. RESULTS The repeatability of this method had a low relative standard deviation (

The present study aims at evaluating potential genotoxic and cytotoxic effects caused by the occupational exposure of farmers to pesticide mixtures in the Aitoloakarnania Prefecture (Greece). The aforementioned assessment was conducted through in vivo Cytokinesis Block Micronucleus assay (CBMN assay) in peripheral blood lymphocytes, in relation to chemical analysis of pesticide residues in blood samples. The exposure of the farmers' population studied to different combinations of pesticides induced significant differences in the frequencies of micronuclei (MN) compared to those of the control group. Furthermore, our results indicated a possible clastogenic and aneugenic effect of pesticides on the genetic material of the farmers exposed. Five pesticides (trifluralin, chlorpyriphos methyl, metolachlor, fenthion and dimethoate) and three metabolites (fenthion sulfone, fenthion sulfoxide and 4,4′ DDE) were detected in the 62.5% of blood samples, with mean concentrations ranging from 0.4 ng/ml to 48 ng/ml. Since the farmers studied probably exhibit detectable levels of systematic exposure to the pesticides applied, continuous educational programs focused on the rational and safe use of pesticides, together with implementation of risk communication strategies among farmers are highly recommended.

Organophosphorus (OP) pesticides are widely used to control pests because of their high activity. This study described a rapid and sensitive lateral flow immunochromatographic (LFIC) assay based on up-converting nanoparticles (UCNPs) for multi-residue detection of three OP pesticides. The developed assay integrated novel fluorescent material UCNPs labeled with a broad-specific monoclonal antibody. Based on the competitive platform by immobilized antigen in the test zone, the optimized UCNPs-LFIC assay enabled sensitive detection for parathion, parathion-methyl, and fenitrothion with IC50 of 3.44, 3.98, and 12.49 ng/mL (R 2 ≥ 0.9776) within 40 min. The detectable ability ranged from 0.98 to 250 ng/mL. There was no cross-reactivity with fenthion, phoxim, isocarbophos, chlorpyrifos, or triazophos, even at a high concentration of 500 ng/mL. Matrix interference from various agricultural products was also studied in food sample detection. In the spiked test, recoveries of the three OP pesticides ranged from 67 to 120% and relative standard deviations were below 19.54%. These results indicated that the proposed strip assay can be an alternative screening tool for rapid detection of the three OP pesticides in food samples.

In this study, the phase I metabolism of fenthion was monitored in three common vegetables in different chamber situations via an in vivo solid-phase microextraction method. The phase I metabolic pathways of fenthion were evaluated based on the in vivo monitoring results and their comparisons among the chamber situations. Enzyme catalysis was found to play a basic and dominant role, whereas light catalysis could promote subsequent transformations that were difficult for enzyme catalysis. Moreover, according to the concentrations of the metabolites and their toxicity, the total concentrations and total toxicity weighted concentrations were calculated to reveal actual residual levels. The relative total and weighted exposure potency values were calculated to account for the fact that only the parent pesticide was considered in the diet exposure risk assessment. In result, both total and weighted approaches indicated a much higher exposure risk. Present study uncovered the potential pesticide exposure risk associated with phase I metabolism and highlighted the toxicity weighted approach, both of which more realistically reflect the exposure risk than the parent compound concentration does. In general, this study may facilitate further illustrating the phase I metabolism of ubiquitous agricultural pesticides, and provide a more realistically understanding of their exposure risk.

An in vivo uptake and elimination tracing study based on solid phase microextraction (SPME) was conducted to investigate the accumulation, persistence and distribution of organochloride pesticides (OCPs) and organophosphorus pesticides (OPPs) in malabar spinach (Basella alba L.) plants. Uptake and elimination of the pesticides were traced in leaves, stems and roots of living malabar spinach plants. Root concentration factor (RCF), distribution concentration factor (DCF) and transpiration stream concentration factor (TSCF) were calculated based on the in vivo tracing data. The tracing data showed that the OCPs were much more accumulative and persistent than the OPPs in roots, while they were similarly accumulative and persistent in leaves and stems. RCF values of the OPPs or OCPs were likely to increase with the increase in LogKow values except fenthion. Obtained DCF values indicated that OPPs and OCPs were more accumulative in the organs containing more lipids. TSCF values showed that the translocation of OPPs and OCPs from roots to foliage was firstly dependent on the hydrophobicity of the compounds, but also significantly affected by the water solubility. This is the first study of generating RCF, DCF and TSCF data in living plants by in vivo sampling method, which provides a foundation to promote the application of in vivo SPME and improve understanding of contaminant behaviors in living plants.

In vivo solid-phase microextraction (SPME) sampling method coupled with gas chromatography-mass spectrometry (GC-MS) analysis was employed to trace the uptake and elimination of organophosphorus pesticides (OPPs) in two kinds of edible plants, cabbage (Brassica parachinensis) and aloe (Barbadensis). The metabolism of fenthion in aloe was also investigated by the liquid chromatography tandem mass spectrometry analysis (LC-MS/MS) to understand the fate of OPPs in living plants better. Transpiration stream concentration factor (TSCF) and depuration rate constants of the OPPs in living plants were obtained therein. The health risk of the OPPs treated aloe was estimated by the maximum residue limit (MRL) approach, and it revealed that the OPPs were rather safe for their fast degradable property. However, peak concentration of fenthion-sulfoxide was found to exceed the MRL and was higher than that of the parent fenthion, which indicated the potential risk of pesticide metabolites. This study highlighted the application of in vivo SPME for contaminant tracing in different living edible plants. The in vivo tracing method is very convenient and can provide more data to evaluate the risk of different pesticides, which are very important for the safety of agriculture production.

Attract-and-kill is a possible alternative to the conventional control of Mediterranean fruit fly (medfly), Ceratitis capitata Wiedemann (Diptera: Tephritidae) with bait or cover sprays of organophosphate insecticides. In this study, we determined if an attract-and-kill device (MagMED ® ) could be applied alone at the recommended rate (80 devices/ha), or needed to be combined with other conventional control tactics to suppress medfly in deciduous fruit orchards (apple, nectarine, peach, pear, plum). We also determined if attract-and-kill had any detrimental effects on naturally occurring beneficial insects. Based on an acceptable level of crop loss of 2–5% (the level of crop loss growers can tolerate), attract-and-kill suppressed medfly and reduced crop loss below the acceptable level in orchards with additional controls. Attract-and-kill was most effective when combined with either bait spraying, cover spraying or both. Combining attract-and-kill with cover sprays of fenthion resulted in a drop in crop loss of apples from 2.5% to 0.5%. By combining attract-and-kill with weekly bait sprays and two cover spray applications, crop loss fell from 13.7% to 4.3% in peaches, from 6.3% to 5% in nectarines and from 6.3% to 3.7% in pears. Twice weekly bait spraying was the most effective technique at suppressing medfly, providing acceptable control when applied alone, which further improved by combining with attract-and-kill. By combining attract-and-kill with twice weekly bait spraying crop loss fell from 2% to 1% in nectarines and from 4% to 2% in apples. In laboratory trials, attract-and-kill devices killed 100% of brown lacewings ( Micromus tasmaniae Walker) and 94% of transverse ladybeetles ( Coccinella transversalis Fabricius) 24 h after contact. However, orchard samples suggest that it may not pose any significant negative impact on naturally occurring beneficials such as Neuroptera, Hymenoptera, Coleoptera, Thysanoptera and Syrphidae in the field.