Search

Monitoring fenitrothion (FNT) residues in food and the environment is crucial due to its high environmental toxicity. In this study, we developed a sensitive, reliable electrochemical method for detecting FNT by using screen-printed carbon electrodes (SPCE) modified with porous graphene oxide (PGO) nanosheets. PGO surface properties have been meticulously characterized using advanced spectroscopic techniques. Electrochemical impedance spectroscopy and cyclic voltammetry were used to test the electrochemical properties of the PGO-modified sensor. The PGO-modified sensor exhibited remarkable sensitivity, achieving a detection limit as low as 0.061 μM and a broad linear range of 0.02-250 μM. Enhanced performance is due to PGO's high surface area and excellent electrocatalytic properties, which greatly improved electron transfer. Square wave voltammetry was used to demonstrate the sensor's efficacy as a real-time, on-site monitoring tool for FNT residues in fruit and water. The outstanding performance of the PGO/SPCE sensor underscores its applicability in ensuring food safety and environmental protection., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background: Hypospadias is a male genital tract defect for which an increase in prevalence has been documented over the last few decades. A role for environmental risk factors is suspected, including prenatal exposure to pesticides., Objectives: To study the risk of hypospadias in association with multiple pesticide measurements in meconium samples., Methods: The Brittany Registry of Congenital Anomalies (France) conducted a case-control study between 2012 and 2018. Cases were hypospadias, ascertained by a pediatrician and a pediatric surgeon, excluding genetic conditions, following European Surveillance of Congenital Anomalies guidelines (N = 69). Controls (N = 135) were two male infants without congenital anomaly born after each case in the same maternity unit. Mothers in the maternity units completed a self-administered questionnaire, we collected medical data from hospital records, and medical staff collected meconium samples. We performed chemical analysis of 38 pesticides (parent compound and/or metabolite) by UHPLC/MS/MS following strict quality assurance/quality control criteria and blind to case-control status. We carried out logistic regression accounting for frequency-matching variables and major risk factors., Results: Among the 38 pesticides measured, 16 (42%) were never detected in the meconium samples, 18 (47%) were in <5% of samples, and 4 (11%) in ≥5% of the samples. We observed an association between the detection of fenitrothion in meconium and the risk of hypospadias (OR = 2.6 [1.0-6.3] with n cases = 13, n controls = 21), but not the other pesticides., Conclusions: Our small study provides a robust assessment of fetal exposure. Fenitrothion's established antiandrogenic activities provide biologic plausibility for our observations. Further studies are needed to confirm this hypothesis., Competing Interests: The authors report no conflicts of interest., (Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.)

Background: Supercritical fluid extraction (SFE) is a fast, versatile, and solvent-efficient automatic extraction method. Despite its advantages, the results of our proficiency tests imply that the applicability assessments of SFE for pesticide residues were insufficient., Objective: In this study, as analytical method using SFE was optimized and validated by testing the incurred and fortified brown rice samples with organophosphorus (OP), pyrethroid (PYR), and dithiolane (DIT) pesticides., Method: A validation study using the incurred sample with etofenprox, fenitrothion, and isoprothiolane was performed by comparing the analytical results obtained using the SFE and solid-liquid extraction with homogenization (SLE), which is a well-validated official multi-residue extraction method. The tests on the fortified samples were also performed for seven pesticide residues, chlorpyrifos, diazinon, O-ethyl O-4-nitrophenyl phenylphosphonothioate (EPN), etofenprox, fenitrothion, isoxathion, and isoprothiolane, at three fortification levels, 0.001, 0.01, and 0.1 mg/kg., Results: In the test on the incurred samples, optimized SFE-to-SLE analytical values (CSFE/CSLE) were 99.2-100.1%, with RSD lower than 3%. In contrast, the analytical-to-spiked concentrations in the tests on the fortified samples were 96.4-105.0%, with RSD lower than 8.8%., Conclusions: These results indicate that the proposed SFE method, which is well validated with the incurred brown rice sample, is useful for determining OP, PYR, and DIT pesticide residues in brown rice., Highlights: The proposed SFE method satisfies EU and Japanese maximum residue limits (MRLs). The consumption of solvent can be reduced to one-fourth of that of SLE using the proposed SFE method., (© The Author(s) 2023. Published by Oxford University Press on behalf of AOAC INTERNATIONAL. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Background: Ultrasound has the potential to increase microbial metabolic activity, so this study explored the stimulatory effect of ultrasound pre-treatment on the degradation of four common pesticides (fenitrothion, chlorpyrifos, profenofos, and dimethoate) during milk fermentation by Lactobacillus plantarum and its effect on yogurt quality., Results: Appropriate ultrasound pretreatment significantly enhanced the growth of L. plantarum. The degradation percentages of pesticides increased by 19-38% under ultrasound treatment. Ultrasonic intensity, pulse duty cycle, and duration time were key factors affecting microbial growth and pesticide degradation. Under optimal ultrasonic pre-treatment conditions, the degradation rate constants of four pesticides were at least 3.4 times higher than those without sonication. In addition, such ultrasound pretreatment significantly shortened yogurt fermentation time, increased the water holding capacity, hardness and antioxidant activity of the yogurt, and improved the flavor quality of the yogurt., Conclusion: Ultrasonic pretreatment significantly accelerated the degradation of the four pesticides during yogurt fermentation. In addition, such ultrasound pretreatment increased the efficiency of yogurt making and improved the quality of yogurt in terms of water holding capacity, firmness, antioxidant activity, and flavor. These findings provide a basis for the application of ultrasound to the removal of pesticide residues and quality improvement of yogurt. © 2022 Society of Chemical Industry., (© 2022 Society of Chemical Industry.)

The fate of five pesticides comprising triadimefon, imidacloprid, fenitrothion, chlorpyrifos-methyl, and chlorpyrifos in wheat flour during noodle production and accelerated storage was systematically investigated. Pesticide residues were determined by high-performance liquid chromatography with diode array detection (HPLC-DAD) after each processing step and accelerated storage. The results indicated that dough mixing reduced the concentration of five pesticide residues by 23-42%, mainly owing to the increase of moisture content. Dough resting had little effect on the residues of triadimefon, imidacloprid, and fenitrothion, but decreased chlorpyrifos-methyl and chlorpyrifos significantly by 24% and 15%, respectively. The pesticide residues increased by 3% to 69% during the drying step, attributed to the different role played by thermal evaporation or thermal degradation and concentration of the different pesticides. Boiling lowered the pesticide residues significantly by 56% to 74% in both fresh noodles and dried noodles. All the pesticide residues decreased during accelerated storage, especially for fenitrothion, chlorpyrifos-methyl, and chlorpyrifos. The processing factors (PFs) of the five pesticides in the drying step were greater than 1, while the others were all less than 1. The whole process for noodle production was beneficial to reduce the pesticide residues with PFs ranging from 0.15 to 0.35. The PFs of five pesticides in accelerated storage were all below 1.

Fenitrothion is an insecticide belonging to the organophosphate family of pesticides that is widely used around the world in agriculture and living environments. Today, it is one of the most hazardous chemicals that causes severe environmental pollution. However, detection of fenitrothion residues in the environment is considered a significant challenge due to the small molecule nature of the insecticide and lack of molecular recognition elements that can detect it with high specificity. We performed in vitro selection experiments using the SELEX process to isolate the DNA aptamers that can bind to fenitrothion. We found that newly discovered DNA aptamers have a strong ability to distinguish fenitrothion from other organophosphate insecticides (non-specific targets). Furthermore, we identified a fenitrothion-specific aptamer; FenA2, that can interact with Thioflavin T (ThT) to produce a label-free detection mode with a K d of 33.57 nM (9.30 ppb) and LOD of 14 nM (3.88 ppb). Additionally, the FenA2 aptamer exhibited very low cross-reactivity with non-specific targets. This is the first report showing an aptamer sensor with a G4-quadruplex-like structure to detect fenitrothion. Moreover, these aptamers have the potential to be further developed into analytical tools for real-time detection of fenitrothion from a wide range of samples.

Enzyme inhibition assay was used as a biomarker for detection of organophosphates pesticides in food and environmental samples. The aim of the present study was to optimize the time of enzyme-inhibitor reaction for quantitative determination of fenitrothion organophosphate based on cholinesterase inhibition. The results showed that this method provides a time-efficient, best linearity and simple assay. The effect of reaction time on the linearity relationship of the noncompetitive inhibition equation was studied. The best linearity of the assay was found at an optimum reaction time of 3.0 min, with coefficient of determination r 2 of 0.9972, in the range of inhibitor concentrations from 0.016 to 2.0 μg mL -1 . The enzyme inhibition reached a plateau at 5 min by addition of pesticide in vitro and then the inhibited enzyme reactivate spontaneously and approached steady state at 20 min. A theoretical kinetic model to explain the effect of reaction time on the enzyme inhibition by addition of pesticide in vitro was derived. The higher values of coefficient of determination r 2 for the predicted model and error functions of the minimum deviations suggest that this model can be used to represent the experimental data and explain the plasma cholinesterase inhibition by fenitrothion pesticide.

A sensitive and readily deployable analytical method has been reported for the simultaneous analysis of pirimicarb (PRM) and fenitrothion (FEN) pesticide residues in environmental water samples using fabric phase sorptive extraction (FPSE) followed by high-performance liquid chromatography combined with photodiode array (HPLC-PDA) detector. Both pesticides were successfully determined with a Luna omega C18 column under isocratic elution mode by means of acetonitrile and phosphate buffer (pH 3.0) as the mobile phase. The quantitative data for PRM and FEN were obtained at their maximum wavelengths of 310 nm and 268 nm, respectively. The calibration plots were linear in the range 10.00-750.00 ng mL -1 and 10.00-900.00 ng mL -1 with correlation coefficient of 0.9984 and 0.9992 for PRM and FEN, respectively. Major FPSE experimental variables were investigated in detail, such as contact time with the FPSE membrane, pH and electrolyte concentration, and the volume and type of desorption solvent. Under the optimized conditions, the developed method showed satisfactory reproducibility with relative standard deviations less than 2.5% and low limits of detection of 2.98 and 3.02 ng mL -1 for PRM and FEN, respectively. The combined procedure allows for enhancement factors ranging from 88 to 113, with pre-concentration values of 125 for both analytes. The chromatographic resolutions were approx. 12 for FEN (retention factor of 3.52) and PRM (retention factor of 6.09), respectively, with a selectivity factor of 1.73. Finally, the validated method was successfully applied to real environmental water samples for the determination of these pesticides. Graphical abstract.

Kinetic and validation of the enzymatic method for the determination of fenitrothion organophosphorus based on cholinesterase inhibition were studied. A Linear relationship was obtained with a determination coefficient R 2 of 0.9989 suggesting that the noncompetitive inhibition kinetic equation is suitable to represent the enzymatic assay of fenitrothion. The value of the inhibition constant K I was 0.374 μg/ml/min. The analytical logarithmic curve for the determination of fenitrothion concentration using the percentage of cholinesterase inhibition presented good linear relations at concentrations of 0.05-2 μg/ml ( R 2 = 0.9889). The maximum inhibition 83% was observed at 2.0 μg/ml final assay concentration. The lower inhibition 3.3% was observed at 0.05 μg/ml detection limit. The experimental measurement condition was optimized. The enzymatic method exhibited detection limits (LOD) in the range of 0.05-2.0 μg/ml. The limit of quantification (LOQ) was 0.06 μg/ml with inhibition 13%. The concentration of fenitrothion that inhibited the hydrolysis of substrate by 50% (IC50 value) was 0.4 μg/ml. Standard deviations and coefficients of variation indicate a good precision of the enzymatic method for the detection of organophosphate insecticides at an incubation time of 20 min.

A sensitive, rapid, reliable, and easily applicable method based on magnetic solid phase extraction (MSPE) combined with HPLC-PDA was developed for monitoring propoxur (PRO) and fenitrothion (FEN) pesticides in environmental water samples. The effect of major experimental variables on the extraction efficiency of both the pesticides was investigated and optimized systematically. For this purpose, a new magnetic material containing decanoic acid on the surface of particles was synthesized and characterized by XRD, FT-IR, SEM, EDX, and TGA analysis in detail. The simultaneous determination of pesticide molecules was carried out by using a Luna Omega C18 column, isocratic elution of acetonitrile (ACN): Water (70:30 v / v ) with a flow rate of 1.2 mL min -1 . After MSPE, the linear range for pesticide molecules (r 2 > 0.9982) was obtained in the range of 5-800 and 10-800 ng mL -1 , respectively. The limit of detections (LOD) are 1.43 and 4.71 ng mL -1 for PRO and FEN, respectively while RSDs % are below 3.5%. The applicability of the proposed method in four different environmental samples were also investigated using a standard addition-recovery procedure. Average recoveries at two spiking levels were over the range of 91.3-102.5% with RSD < 5.0% ( n = 3). The obtained results show that decanoic acid grafted magnetic particles in MSPE combined with HPLC-PDA is a fast and simple method for the determination of PRO and FEN in environmental water samples.

A surface plasmon resonance study was carried out for the identification and determination of the organophosphate pesticide fenitrothion via an optical fiber sensor. A thin layer of silver was deposited on the unclad core of silica optical fiber for plasmon generation. This was followed by the deposition of a sensing surface comprising a layer of tantalum(V) oxide nanoparticles sequestered in a nano-scaled matrix of reduced graphene oxide. The sensing mechanism is due to the interaction of fenitrothion with the silver film which leads to a change in refractive index.. Characterized by a wavelength interrogation scheme, the fiber-optic sensor exhibited a red shift equalling 56 nm corresponding to fenitrothion concentration in the range 0.25-4 μM including the blank solution. The spectral sensitivity is 24 nm μM -1 , the limit of detection is 38 nM, and the response time is as short as 23 s. The sensor is selective, repeatable and works at ambient temperature. Graphical abstractSchematic representation of the sensing mechanism of an SPR based fiber-optic fenitrothion sensor utilizing modification in refractive index of sensing surface comprising of tantalum(V) oxide (Ta 2 O 5 ) nanoparticles embedded in reduced graphene oxide (rGO) caused by interaction with fenitrothion entities.

We have reported an effective electrochemical sensor for assorted pesticide (i.e., Fenitrothion). Exact tracking of these pesticides has become more important for protecting the environment and food resources owing to their high toxicity. Hence, the development of compatible sensors for the real-time detection of pesticides is imperative to overcome practical limitations encountered in conventional methodologies. In this regard, the role of the novel, advanced functional materials such as niobium carbide (NbC) supported on molybdenum nanoparticles (NbC@Mo) has drawn great consideration in conventional sensory systems because of their numerous advantages over other nanomaterials. The nanocomposite was characterized by XRD, XPS, HR-TEM, and EIS. Under optimized working conditions, the modified electrode NbC@Mo/SPCE responds linearly as 0.01-1889 μM concentration range and the detection limit is 0.15 nM. Most importantly, the method was successfully demonstrated in fruit samples., (Copyright © 2018 Elsevier B.V. All rights reserved.)

This paper reports the electrosynthesis and characterisation of a polymeric film derived from 2-hydroxybenzamide over a graphite electrode and its application as an enzymatic biosensor for the determination and quantification of the pesticide fenitrothion. The material was analysed by scanning electron microscopy and its electrochemical properties characterised by cyclic voltammetry and electrochemical impedance spectroscopy. The enzyme tyrosinase was immobilised over the modified electrode by the drop and dry technique. Catechol was determined by direct reduction of biocatalytically formed o-quinone by employing the flow injection analysis technique. The analytical characteristics of the proposed sensor were optimised as follows: phosphate buffer 0.050 M at pH 6.5, flow rate 5.0 mL min -1 , sample injection volume 150 μL, catechol concentration 1.0 mM and maximum inhibition time by fenitrothion of 6 min. The biosensors showed a linear response to pesticide concentration from 0.018 to 3.60 μM. The limit of detection and limit of quantification were calculated as 4.70 nM and 15.9 nM (RSD < 2.7%), respectively. The intra- and inter-electrode RSDs were 3.35% (n = 15) and 8.70% (n = 7), respectively. In addition, water samples spiked with the pesticide showed an average recovery of 97.6% (±1.53)., (Copyright © 2018 Elsevier Inc. All rights reserved.)

A simple, environmentally benign, and rapid method based on temperature-controlled liquid-liquid microextraction using a deep eutectic solvent was developed for the simultaneous extraction/preconcentration of diazinon and fenitrothion. The method involved the addition of deep eutectic solvent to the aqueous sample followed by heating the mixture in a 75°C water bath until the solvent was completely dissolved in the aqueous phase. Then, the resultant solution was cooled in an ice bath and a cloudy solution was formed. Afterward, the mixture was centrifuged and the enriched deep eutectic solvent phase was analyzed by high-performance liquid chromatography with ultraviolet detection for quantification of the analytes. The factors affecting the extraction efficiency were optimized. Under the optimized extraction conditions, the limits of detection for diazinon and fenitrothion were 0.3 and 0.15 μg/L, respectively. The calibration curves for diazinon and fenitrothion exhibited linearity in the concentration range of 1-100 and 0.5-100 μg/L, respectively. The relative standard deviations for five replicate measurements at 10.0 μg/L level of analytes were less than 2.8 and 4.5% for intra- and interday assays, respectively. The developed method was successfully applied to the determination of diazinon and fenitrothion in water and fruit juice samples., (© 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

A new type of adsorbent composed of magnetic three-dimensional graphene coated with silver nanoparticles was synthesized by an electroless technique and used in the magnetic solid-phase extraction of selected pesticides (fenitrothion, chlorpyrifos, and hexaconazole) before gas chromatography with a micro-electron capture detector. The adsorbent was characterized using Fourier-transform infrared spectroscopy, X-ray diffraction, vibrating sample magnetometry, and field-emission scanning electron microscopy. The important extraction parameters such as pH, adsorbent dose, extraction time, and desorption conditions were investigated. Under the optimal conditions, the analytical figures of merit were obtained as: linear dynamic range of 0.1-5 ng/g with determination coefficients of 0.991-0.996; limit of detection of 0.07-0.13 ng/g; limit of quantification of 0.242-0.448 ng/g; and the intraday and interday relative standard deviations (C = 5 ng/g, n = 3) were 3.8-8.7 and 6.6-8.9%, respectively. The developed method was successfully applied for analysis of the selected pesticides in tomato and grape with extraction recoveries in the range of 72.8-109.6%., (© 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

We measured the concentrations of organophosphorus pesticide （chlorpyrifos-methyl, pirimiphos-methyl and fenitrothion） residues in domestic and imported commercial wheat products （flour, noodles, cookies） collected from 2008 to 2016. Chlorpyrifos-methyl and fenitrothion in domestic flour samples were detected in 16 out of 34 samples at levels of ＜0.001 to 0.016 ppm, and in 14 out of 34 samples at levels of ＜0.001 to 0.004 ppm. Chlorpyrifos-methyl was detected in 22 out of 38 domestic cookies at levels of ＜0.001 to 0.054 ppm （median: 0.001 ppm）. Relatively high concentrations of chlorpyrifos-methyl （0.005 to 0.054 ppm） were found in six domestic cookies containing wheat bran. Pirimiphos-methyl was detected in 32 out of 68 cookies from foreign countries at levels of ＜0.001 to 0.11 ppm. Pirimiphos-methyl was detected frequently in products imported from Europe.

In this study, the detailed metabolic pathways of fenitrothion (FNT), an organophosphorus insecticide by Cunninghamella elegans, were investigated. Approximately 81% of FNT was degraded within 5 days after treatment with concomitant accumulation of four metabolites (M1-M4). The four metabolites were separated by high-performance liquid chromatography, and their structures were identified by mass spectroscopy and/or nuclear magnetic resonance. M3 is confirmed to be an initial precursor of others and identified as fenitrothion-oxon. On the basis of their metabolic profiling, the possible metabolic pathways involved in phase I and II metabolism of FNT by C. elegans was proposed. We also found that C. elegans was able to efficiently and rapidly degrade other organophosphorus pesticides (OPs). Thus, these results will provide insight into understanding of the fungal degradation of FNT and the potential application for bioremediation of OPs. Furthermore, the ability of C. elegans to mimic mammalian metabolism would help us elucidate the metabolic fates of organic compounds occurring in mammalian liver cells and evaluate their toxicity and potential adverse effects.

We herein report a fatal intoxication case caused by the ingestion of the insecticides chlorpyrifos-methyl (CPFM) and fenitrothion (MEP). A 70-year-old man was found dead in his house and a cup containing a small amount of agricultural chemicals was on the table near his body. External and internal examinations revealed no injuries. In a gas chromatography-mass spectrometry (GC-MS) screening test, CPFM, MEP, and their metabolites, 3,5,6-trichloro-2-pyridinol (TCPY) and 3-methyl-4-nitrophenol (3MNP), respectively, were qualitatively detected in his stomach contents. The concentrations (µg/g) of CPFM, TCPY, MEP, and 3MNP in the extracts of each body fluid and organ tissue were assessed by GC-MS and were as follows: 27.8, 56.2, 17.2, and 2.82 (heart blood); 6.60, 42.9, 1.80, and 2.59 (peripheral blood); 0.0821, 45.9, 2,09, and 102 (urine); 21.4, 26.6, 76.2, and 3.83 (brain (frontal portion)); 16.1, 101, 9.67, and 1.26 (liver); 7.45, 101, 21.4, and 26.1 (right kidney); and 73,500, 9750, 232,000, and 1880 (stomach contents), respectively. Based on these results and autopsy findings, the cause of death was acute fatal intoxication by CPFM and MEP., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Three-dimensional (3D) printing has proven to be a versatile and useful technology for specialized applications in industry and also for scientific research. We demonstrate its potential use toward the electrochemical detection of nitroaromatic compounds 2,4,6-trinitrotoluene (TNT), 2,4-dinitrotoluene (DNT), and fenitrothion (FT). The detection of these compounds is of utmost importance in military and forensic applications. Stainless steel electrodes were fabricated by 3D printing, and the surface was electroplated with gold. The electrochemical performance of the 3D printed electrodes was compared to that of the conventionally employed glassy carbon electrode (GCE) and proved to be more sensitive toward the detection of all three nitroaromatic compounds. 3D printing of customizable electrodes provides a viable alternative to traditional electrodes for the analysis of samples with electrochemical methods.

A simple and rapid gas chromatography with flame photometric detector (GC-FPD) determination method was developed to detect residue levels and investigate the dissipation pattern and safe use of fenitrothion in tomatoes. A modified quick, easy, cheap, effective, rugged, and safe (QuEChERS) using an ethyl acetate-based extraction, followed by a dispersive solid-phase extraction (d-SPE) with primary-secondary amine (PSA) and graphite carbon black (GCB) for clean up, was applied prior to GC-FPD analysis. The method showed satisfactory linearity, recovery and precision. The limits of detection (LOD) and quantification (LOQ) were 0.005 and 0.01mg/kg, respectively. The residue levels of fenitrothion were best described by first order kinetics with a half-life of 2.2days in tomatoes. The potential health risks posed by fenitrothion were not significant, based on supervised residue trial data. The current findings could provide guidance for safe and reasonable use of fenitrothion in tomatoes and prevent health problems to consumers., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

A combination of a novel synthesized azo dye (E)-1-(4-((4-(phenylamino)phenyl)diazenyl) phenyl)ethanone and reduced graphene oxide was used to electrochemically modify the surface of a pencil graphite electrode. The surfaces of the modified electrodes were characterized using electrochemical techniques (cyclic voltammetry and electrochemical impedance spectroscopy) and spectroscopic techniques (scanning electron microscopy and attenuated total reflectance). This azo dye/reduced graphene oxide modified electrode was applied first time for the electrochemical detection of an organophosphorus pesticide, fenitrothion. The modified pencil graphite electrode displayed excellent performance for the detection of fenitrothion. Cyclic voltammetry was used to study the dependence of the scan rate on the peak current and peak potential and to determine the kinetic parameters for fenitrothion. Square wave voltammetry was used to determine the effect of pH on the peak potential and for the sensitive and selective detection of fenitrothion using the modified electrode. Satisfactory results were obtained with the proposed sensor for the analysis of FT in tomato samples., (Copyright © 2017 Elsevier B.V. All rights reserved.)

The practice of large-scale agriculture requires the use of pesticides in order to maximize production. This activity has gained increasing attention in recent years, especially from rural workers, due to the risks associated with long-term exposure to pesticides. To minimize these risks, personal protection equipment (e.g., covers, gloves, and goggles) and collective protection equipment (e.g., agricultural tractors with sealed cabins) have been developed. In general, these approaches are intended to reduce the contact of farmers and agricultural machinery operators with the more toxic and stable compounds, an example of which is fenitrothion. In this study, fenitrothion was used as a marker to evaluate the protection afforded inside a sealed tractor cabin. To simulate the pesticide exposure, tests were performed using artificial cotton targets as passive adsorptive agents inside the cabin during the pesticide application. Samples were extracted according to the US Environmental Protection Agency (USEPA) procedure using ultrasonic extraction and as proposed by the Brazilian Standard for Solid Waste Classification (NBR 10004). The extracts were analyzed by high-performance liquid chromatography with diode array detection (HPLC-DAD). The chromatographic method was optimized using a factorial design. The combined results indicated that the best conditions were achieved using a mobile phase with a water/acetonitrile ratio of 35:65, a column temperature of 40 °C, and a flow rate of 1.0 mL/min, with a total analysis time of <10 min. The method was evaluated in the linear range of 0.50 to 2.01 mg/kg, with a determination coefficient of 0.9886. The precision was evaluated on different days and the relative standard deviations were between 0.17 and 3.41 %. In relation to the accuracy, recovery values of 95 to 104 % were obtained. The detection and quantification limits were 0.18 and 0.50 mg/kg, respectively. None of the target cottons showed concentrations of fenitrothion above the limit of detection of 0.18 mg/kg.

It is useful for whole-cell biosensors to be based on colorimetric detection because the output signal can be easily visualized. However, colorimetric-based whole-cell biosensors suffer higher detection limits as compared to bioluminescence- or fluorescence-based biosensors. In this work, we attempt to reduce the detection limit for a colorimetric-based whole-cell biosensor by applying directed evolution techniques on a transcription regulator, DmpR, to alter the expression level of its cognate promoter, which was fused to mRFP1 to output red coloration in the presence of organophosphate pesticides containing a phenolic group. We selected the two best-performing mutants, DM01 and DM12, which were able to develop red coloration in the presence of parathion as low as 10 μM after just 6 h of induction at 30 °C. This suggests that engineering of the transcription regulator in the sensing domain is useful for improving various properties of whole-cell biosensors, such as reducing the detection limit for simple colorimetric detection of organophosphate pesticides.

A mass distribution model was used to predict the fate of Diuron, Irgarol 1051 and Fenitrothion in Seto Inland Sea which is located in western Japan. This was done by using concentration, degradation, and literature data. Diuron and Irgarol 1051 in Seto Inland Sea are mainly derived from antifouling paints used for ships and boats. On the other hand Fenitrothion exclusively comes from land via rivers and atmospheric deposition. The total inputs/yr to Seto Inland Sea were found to be 104 tons, 7.65 tons and 5.14 tons for Diuron, Irgarol 1051 and Fenitrothion, respectively. The pesticide residence times were 0.26 yr, 0.36 yr and 0.17 yr for Diuron, Irgarol 1051 and Fenitrothion, respectively. Photodegradation was faster than biodegradation. In seawater, the half-life ranges were 37.9-57.3 d for photodegradation. In the same seawater the half-life ranges were 1650-2394 d for biodegradation. Photodegradation is effective in surface water (0-5 m depth) while biodegradation occurs throughout the entire water column. Plankton and fishes accumulate these pesticides significantly. The pesticides are deposited (sorbed and buried with) sediments (between 74 and 87% of total input amounts). The open ocean is an important sink accounting for between 8 and 17% of the total pesticide input amounts while photo- and biodegradation accounts for a small percentage., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

For the sensitive and convenient detection of pesticides, several sensing methods and materials have been widely explored. However, it is still a challenge to obtain sensitive, simple detection techniques for pesticides. Here, the simple and sensitive Time-resolved SERS mapping (T-SERS) and Spatial-resolved SERS mapping (S-SERS) are presented for detection of pesticides by using Au@Ag NPs as SERS substrate. The Time-resolved SERS mapping (T-SERS) is based on state translation nanoparticles from the wet state to the dry state to realize SERS measurements. During the SERS measurement, adhesive force drives the particles closer together and then average interparticle gap becomes smaller. Following, air then begins to intersperse into the liquid network and the particles are held together by adhesive forces at the solid-liquid-air interface. In the late stage of water evaporation, all particles are uniformly distributed. Thus, so called hotspots matrix that can hold hotspots between every two adjacent particles in efficient space with minimal polydispersity of particle size are achieved, accompanying the red-shift of surface plasmon peak and appearance of an optimal SPR resonated sharply with excitation wavelength. Here, we found that the T-SERS method exhibits the detection limits of 1-2 orders of magnitude higher than that of S-SERS. On the other hand, the T-SERS is very simple method with high detection sensitivity, better reproducibility (RSD=10.8%) and is beneficial to construction of a calibration curve in comparison with that of Spatial-resolved SERS mapping (S-SERS). Most importantly, as a result of its remarkable sensitivity, T-SERS mapping strategies have been applied to detection of several pesticides and the detect limit can down to 1nM for paraoxon, 0.5nM for sumithion. In short, T-SERS mapping measurement promises to open a market for SERS practical detection with prominent advantages., (Copyright © 2015. Published by Elsevier B.V.)

A study was conducted on the pesticides Diuron, Irgarol 1051 and Fenitrothion in Kurose River water, Higashi Hiroshima, Japan for a period of one year to assess the contribution of agriculture and urban activities on pesticide pollution of the river. Samples were analysed by a reverse phase HPLC system. The maximum pesticide concentrations were; 4620 ng/L, 50 ng/L and 370 ng/L for Diuron, Irgarol 1051 and Fenitrothion, respectively. While Diuron and Fenitrothion were detected at all sites, Irgarol 1051 was only present at Izumi, a high density urban and industrial area which also registered the highest concentrations of the pesticides. The pattern showed by Diuron and Fenitrothion was linked to farming activities. Also, Diuron and Fenitrothion concentration correlated with pesticide utilization data for Hiroshima Prefecture. Irgarol 1051 showed a different pattern to that of Diuron and Fenitrothion and its source was attributed to paint. It was noted that 78% and 42% of water samples at Izumi sampling site exceeded the European Union (EU) guidelines for Diuron and Fenitrothion, respectively., (Copyright © 2015 Elsevier B.V. All rights reserved.)

Proficiency testing (PT) for the determination of pesticide residues in soybean samples was organized by the National Metrology Institute of Japan (NMIJ). The candidate certified reference material, NMIJ CRM 7509-a, that was prepared from the raw soybeans containing target pesticides (diazinon, fenitrothion, chlorpyrifos, and permethrin) was used as the test sample. Forty participants submitted two sets of analytical results along with the details of the analytical method and conditions they applied. Two types of assigned values were established for each target pesticide: one was derived from the analytical results of the participants, and the other was provided from the analytical results by isotope-dilution mass spectrometry (IDMS). The latter values were 7.4-16% higher than the former values, plausibly because the analytical values from the IDMS measurements were not affected by the recovery ratio of the target pesticides during the analytical process. Thus, two kinds of z-scores were calculated for individual participants using the corresponding assigned values: one (z1-score) showed the relative performance score for the present PT and the other (z2-score) could be used for evaluation of the trueness of their analytical methods., (Copyright © 2014 Elsevier B.V. All rights reserved.)

In this study, an automatic microfluidic fluorescence-array measurement system is developed to detect the concentration of organic phosphate based on the luminol-hydrogen peroxide catalytic fluorescent mechanism. Not only sample quantity and cost can be reduced, but also detection time, accuracy and precision can be improved in the system. The system is composed of a CCD image module, a stepper motor with driver, a microfluidic fluorescence array, a background light elimination module, and a dynamic image-analyzed interface. The pesticides of chlorpyrifos and fenitrothion of organic phosphate are chosen as experimental samples. Only a 2.5 μ l quantity of sample is required to have a fast response time of 1.4 second. Experimental results show that the sensitivities of chlorpyrifos and fenitrothion are 1.88 V/ppm in the range of 0.166 ∼ 10 ppm with averaged error of 1.66% and 0.32 V/ppm in the range of 0.03 ∼ 10 ppm with averaged error of 1.68% respectively. The organophosphorus effective detection range of the developed system covers the legal prescription for pesticide residues.

A novel water-compatible fenitrothion imprinted polymer was prepared on Au nanoparticles (AuNPs) by click chemistry and reversible addition-fragmentation chain transfer (RAFT) precipitation polymerization (RAFTPP). The RAFT chain-transfer agent was synthesized on the surface of AuNPs using click chemistry, then an imprinted polymer with hydrophilic polymer brushes was prepared on the RAFT chain-transfer agent modified AuNPs by RAFTPP, mediated by hydrophilic polyethylene glycol macromolecular cochain-transfer agent. The obtained molecularly imprinted material showed improved accessibility to fenitrothion and recognition property in water medium. When the material was immobilized on an ionic liquid functionalized graphene coated glassy carbon electrode for the electrochemical determination of fenitrothion, the resulting electrochemical sensor presented linear response in the range of 0.01-5 μM, with a sensitivity of 6.1 μA/μM mm(2). The low limit of detection was 8 nM (S/N=3). The sensor was successfully applied to the determination of real samples and the recovery for standard added was 95-108%., (Copyright © 2014 Elsevier B.V. All rights reserved.)

Water pollution represents a threat of increasing importance to human health. Bivalve mollusks are filter-feeding organisms that can accumulate chemical and microbiological contaminants in their tissues from very low concentrations in the water or sediments. Consumption of contaminated shellfish is one of the main causes of seafood poisoning. Thus, marine bivalves are normally depurated in sterilized seawater for 48 h to allow the removal of bacteria. However, this depuration time might be insufficient to eliminate chemical contaminants from their tissues. We have developed a novel technology that accelerates up to fourfold the excretion rate of xenobiotics in bivalves by treatment with the antioxidant and glutathione (GSH) pro-drug N-acetylcysteine (NAC) during the depuration period. NAC improved dose-dependently the detoxification of the organophosphate (OP) pesticide fenitrothion in the mussel Mytilus galloprovincialis, diminishing its levels up to nearly a hundred fold compared to conventional depuration, by enhancing the glutathione S-transferase (GST) activity and inducing the GSH anabolism (GSH synthesis and reduction by glutathione reductase). Notably, this induction in GSH anabolism and GST activity was also observed in uncontaminated bivalves treated with NAC. As the GSH pathway is involved in the detoxification of many pollutants and biotoxins from harmful algal blooms, we validated this proof of principle in king scallops (Pecten maximus) that naturally accumulated the amnesic shellfish poisoning (ASP) toxin domoic acid. We illustrate here a method that enhances the elimination of organic contaminants in shellfish, opening new avenues of depuration of marine organisms., (Published by Elsevier B.V.)

We report the use of Polystyrene/Ag (PS/Ag) nanoparticles as dynamic surface-enhanced Raman spectroscopy (dynamic-SERS) substrates for sensitive detection of low levels of organophosphorus pesticides. The PS particles clearly observed using Raman microscopy provide the masterplate for in situ growth of Ag NPs, leading to multiple active sites for SERS measurements. Besides obtaining the fingerprints of target molecules and recording time-resolved Raman spectra, this dynamic-SERS method can be used as an ultra-sensitive analytical technique which can enhance 1-2 orders of magnitude the signals of analytes in comparison to that of the traditional methods. On the other hand, importantly, it shows much better correlations between concentration and intensity than does the conventional SERS technique so that it can build the foundation for quantitative analysis of analytes. The as-prepared individual PS/Ag nanoparticle has been demonstrated for the sensitive detection of organophosphorus paraoxon and sumithion. SERS spectra are acquired at different concentrations of each pesticide and linear calibration curves are obtained by monitoring the strongest intensity value of bands arising from stronger stretching mode as a function of analyte concentration. The limits of detection and limits of quantitation are reported for two pesticides. The limit of detection for paraoxon is 96 nM (0.026 ppm) and for sumithion is 34 nM (0.011 ppm). The limits of quantitation are 152 nM (0.042 ppm) and 57 nM (0.016 ppm) for paraoxon and sumithion, respectively. It can be seen that these two organophosphorus pesticides can be detected in the low nM range based on this dynamic-SERS analytical method. Also, in the real sample experiments of paraoxon and sumithion, the results confirm that this dynamic-SERS technique would have potential applicability for quantitative analysis with slight interference., (Copyright © 2014 Elsevier B.V. All rights reserved.)

Organophosphates (OPs) widely exist in ecosystem as toxic substances, for which sensitive and rapid analytical methods are highly requested. In the present work, by using N-terminal of ice nucleation protein (INP) as anchoring motif, a genetically engineered Escherichia coli (E. coli) strain surface displayed mutant organophosphorus hydrolase (OPH) (S5) with improved enzyme activity was successfully constructed. The surface location of INP-OPH fusion was confirmed by SDS-PAGE analysis and enzyme activity assays. The OPH-displayed bacteria facilitate the hydrolysis of p-nitrophenol (PNP) substituted organophosphates to generate PNP, which can be detected spectrometrically at 410 nm. Over 90% of the recombinant protein present on the surface of microbes demonstrated enhanced enzyme activity and long-term stability. The OPH activity of whole cells was 2.16 U/OD₆₀₀ using paraoxon as its substrate, which is the highest value reported so far. The optimal temperature for OPH activity was around 55 °C, and suspended cultures retained almost 100% of its activity over a period of one month at room temperature, exhibiting the better stability than free OPH. The recombinant E. coli strain could be employed as a whole-cell biocatalyst for detecting PNP substituted OPs at wider ranges and lower detection limits. Specifically, the linear ranges of the calibration curves were 0.5-150 μM paraoxon, 1-200 μM parathion and 2.5-200 μM methyl parathion, and limits of detection were 0.2 μM, 0.4 μM and 1 μM for paraoxon, parathion and methyl parathion, respectively (S/N=3). These results indicate that the engineered OPH strain is a promising multifunctional bacterium that could be used for further large-scale industrial and environmental applications., (Copyright © 2013 Elsevier Inc. All rights reserved.)

A reproducible method for monitoring traces of cholinesterase (ChE) inhibitors in acetonitrile extracts from fruits and vegetables is described. The method is based on hypochlorite oxidation and ChE inhibition assay. Four common representative samples of produce were selected from a supermarket to investigate the effect of different matrices on pesticides recoveries and assay precision. The samples were extracted with acetonitrile to prepare them for ChE inhibition assays: if necessary, clean-up was performed using dispersive solid-phase extraction for gas chromatography-mass spectrometry (GC/MS) analyses. Chlorine was tested as an oxidising reagent for the conversion of thiophosphorus pesticides (P=S compounds) into their P=O analogues, which have high ChE-inhibiting activity. Chlorine consumption of individual acetonitrile extracts was determined and was strongly dependent on the individual types of fruits and vegetables. After treating the acetonitrile extracts with an excess hypochlorite at 25°C for 15 min, the ChE-inhibiting activities and detection limits for each chlorine-treated pesticide solution were determined. Matrix composition did not interfere significantly with the determination of the pesticides. Enhanced anti-ChE activities leading to low detection limits (ppb levels) were observed for the chlorine-treated extracts that were spiked with chlorpyrifos, diazinon, fenitrothion, and isoxathion. This combination of oxidative derivatisation and ChE inhibition assays was used successfully to monitor and perform semi-quantitative determination of ChE inhibitors in apple, tomato, cucumber, and strawberry samples.

Carcinus maenas is an invertebrate with worldwide distribution and high ability to adapt to different environments, which is frequently used in environmental monitoring. Despite this, it is not clear how historical exposure to moderate contamination may influence sensitivity to further chemical stress in this important decapod species. This study investigated differential responses to organophosphate fenitrothion of C. maenas from a moderately contaminated estuary and a low impacted one, using in vitro and in vivo biomarker assays. To clarify potential differences in sensitivity, a biochemical characterisation of muscle cholinesterases was first performed. The results indicated acetylcholinesterase (AChE) as the main form present in C. maenas muscle. Exposure assays revealed that crabs from the moderately contaminated site were less sensitive to fenitrothion showing lower AChE inhibition than those from the low impacted site. Other biomarker changes detected in these animals were: increased anaerobic metabolism (muscle lactate dehydrogenase), enhanced phase II biotransformation (glutathione S-transferases in the digestive gland) and antioxidant defences (i.e., activities of glutathione reductase, glutathione peroxidase and catalase, and levels of total glutathiones in the digestive gland). Altogether, the results pointed out a role for the glutathione redox system towards tolerance to fenitrothion exposure.

A method based on matrix solid-phase dispersion (MSPD) and gas chromatography-mass spectrometry to determine pesticides in fish liver and crab hepatopancreas was optimized. Ethyl acetate and acetonitrile were evaluated as elution solvents and their volumes were also checked. The best results were obtained with 1.0 g reused C18 as sorbent, using 5 mL acetonitrile as the elution solvent. Analytical recoveries ranged between 57 and 107% with RSD lower than 26% in fish liver and between 56 and 122% with RSD lower than 21% in crab hepatopancreas. The LOQ values for these compounds ranged from 0.05 to 0.5 mg kg(-1) for crab hepatopancreas and from 0.125 to 1.25 mg kg(-1) for fish liver. MPSD was shown to be easy and fast to use, with a clear advantage regarding costs because it does not need any expensive instrument. The proposed method was successfully applied to determine dimethoate, atrazine, clomazone, fenitrothion, malathion, fipronil and tebuconazole in fish liver and crab hepatopancreas samples., (Copyright © 2013 Elsevier B.V. All rights reserved.)

A technique was developed for simultaneous detection of fenitrothion (FNT) and chlorpyrifos-methyl (CLT) using a photonic suspension array based on silica colloidal crystal beads (SCCBs). The SCCBs were encoded with the characteristic reflection peak originating from the stop-band of colloidal crystal. This approach avoids the bleaching, fading or potential interference seen when encoding by fluorescence. SCCBs with a nanopatterned surface had increased biomolecule binding capacity and improved stability. Under optimal conditions, the proposed suspension array allowed simultaneous detection of the selected pesticides in the ranges of 0.25 to 1024 ng/mL and 0.40 to 735.37 ng/mL, with the limits of detection (LODs) of 0.25 and 0.40 ng/mL, respectively. The suspension array was specific and had no significant cross-reactivity with other chemicals. The mean recoveries in tests in which samples were spiked with target standards were 82.35% to 109.90% with a standard deviation within 9.93% for CLT and 81.64% to 108.10% with a standard deviation within 8.82% for FNT. The proposed method shows a potentially powerful capability for fast quantitative analysis of pesticide residues.

This study investigated the effects of ozone microbubble (OMCB) treatment on the removal of residual fenitrothion (FT) and benomyl pesticides from red and green persimmon leaves, and also the treatment effect on the leaf colours, physical properties and flavour. The continuous bubbling OMCB treatment was more effective than the non-bubbling OMCB treatments at reducing the FT and benomyl agricultural pesticide residues from both the red and green persimmon leaves. Moreover, the bubbling OMCB treatment had no effect on the colour and pulling strength of the leaves. These results indicate that the treatment by bubbling OMCB is an extremely effective method for removing the residues of FT and benomyl in persimmon leaves and has relatively little effect on leaf quality characteristics., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

Unlabelled: In this study, the effects of ozone microbubbles (OMCB) treatment at various water temperatures on the removal of residual fenitrothion (FT) pesticides and on the physical properties of lettuce and cherry tomatoes was examined. The residual FT percentage in lettuce and cherry tomatoes was shown decreased by using higher water temperatures, particularly at 30 °C, resulting in a decrease within the range of 32% to 52%, after the 20-min treatment. In addition, bubbling OMCB treatment did not alter the color and pulling strength of lettuce and cherry tomatoes. These results indicate that bubbling OMCB treatment at 30 °C is a highly effective method for the removal of FT residues in lettuce and cherry tomatoes, with relatively little effect on crop quality., Practical Application: The bubbling OMCB has a potential of reducing the FT reduces on vegetables with no adverse effect on the sensory quality of vegetables., (© 2013 Institute of Food Technologists®)

Homogeneous liquid-liquid extraction via flotation assistance (HoLLE-FA) and gas chromatography-flame ionization detection (GC-FID) was presented for the extraction and determination of fenitrothion in water samples. In this work, a rapid, simple and efficient HoLLE-FA method was developed based on applying low-density organic solvents without employing centrifugation. A special extraction cell was designed to facilitate the collection of low-density solvent extraction in the determination of fenitrothion in water samples. The water sample solution was added into an extraction cell that contained an appropriate mixture of extraction and homogeneous solvents. By using air flotation, the organic solvent was collected at the conical part of the designed cell. Under the optimum conditions, the method performance was studied in terms of the linear dynamic range (LDR from 1.0 up to 100 μg L⁻¹), linearity (r² > 0.998), and precision (repeatability < 8.0%). Also, limit of detection (LOD) of 0.4 μg L⁻¹ was obtained for fenitrothion. The applicability of the HoLLE-FA method was evaluated by the extraction and determination of fenitrothion in three different water samples.

Background: Poland is a leading grower/producer of berries in Europe that are either eaten raw or processed. As well as berries this includes fruit such as grapes, strawberries and other small fruits. Testing for the presence of active substances in Plant Protection Products, (PPP), in such fruit is however important, as part of measures taken to minimise human intake., Objective: To determine the incidence of pesticide residues in berries harvested from South-Eastern Poland in 2009-2011., Material and Methods: . Chromatographic separation followed by analytical detection was performed on 250 samples of various test fruits using an accredited methodology: GC/ECD/NPD, together with spectrophotometric detection wherever necessary, according to PN-EN ISO/IEC 17025. As part of previous monitoring, 126 active substances were identified in 2009, 132 in 2010 and 153 in 2011; levels were compared to Maximum Residue Limits (MRLs). RESULTS;. Analyses showed that 46.4% of samples contained PPPs of which 4% exceeded the MRL. The most were found in raspberries, (58.8% of all tested), followed by 58.3% redcurrants, and gooseberries as well as 50% grapes. The most frequently found active substances of PPPs were pyrimethanil (15.6%), dithiocarbamates (12.4%), procymidone (8%), cyprodinil (5.6%) and difenoconazole (5.2%). The highest MRL exceedances were found in blackcurrants. Testing also revealed many examples of pesticides not recommended for the protection of specific crops: propiconazole in gooseberries, cyprodinil, flusilazole, iprodione, pyrimethanil in blackcurrants and folpet and captan in raspberries. Furthermore, active substances whose use in PPPs have been forbidden since 2008 were also detected, ie. endosulfan in blackcurrants and strawberries, fenitrothion in black and red currants as well as procymidone in raspberries, blackcurrants and strawberries. These data are consistent to those obtained from the whole of Poland and the European Union (EU)., Conclusions: Most pesticides were present in raspberries, redcurrants, gooseberries and grapes of which fungicides were the most frequently detected. These results are in keeping with other similar studies.

In this study, a method for extraction and preconcentration trace amounts of organophosphorus pesticides (OPPs) in environmental water was developed using magnetic solid phase extraction (magnetic-SPE) followed by high performance liquid chromatography (HPLC) with UV detection. Magnetite octadecylsilane nanoparticles were synthesized and characterized by X-ray diffraction, FTIR spectroscopy, vibrating sample magnetometry and scanning electron microscopy. These nanoparticles were applied for extraction and preconcentration of OPPs (residues of diazinon and fenitrothion, which are the most-widely used for pest control in Iran) in environmental water samples at low ng mL(-1) concentration as magnetic-SPE adsorbent. The extraction conditions and efficiency of the nanoparticles for OPPs were investigated. The method was evaluated according to the reproducibility, enrichment factor, linearity range and limits of detection. Under optimized conditions, method showed good linearity between 0.03-0.06 and 30 ng mL(-1) with regression coefficients (R(2)) of 0.997 and 0.998. Limits of detection were 0.019 and 0.014 ng mL(-1). The enrichment factors of this method were 172 and 184 and the analysis yielded good reproducibility with the RSD values 7.2% and 5.4% at the 10 ng mL(-1) level (n=5) for diazinon and fenitrothion, respectively. Determination of OPPs can be easily carried out with this fast, accurate, sensitive and simple method procedure., (Copyright © 2012 Elsevier B.V. All rights reserved.)

In the present study, a cross-linked nano-sized spherical magnetic poly(styrene-divinylbenzene) is synthesized and used as an adsorbent for enrichment-determination of fenitrothion. A miniemulsion polymerization procedure was used to prepare the adsorbent. The magnetic adsorbent was characterized by FT-IR, SEM and TEM. The prepared magnetic adsorbent nanoparticles were mixed with magnetite nanoparticles for faster and more efficient magnetic precipitation. The reduced fenitrothion was coupled with 3-methyl-2-benzothiazolinone hydrazone and then the blue colored complex was extracted. The blue derivative of fenitrothion was eluted by a 1 mL aliquot of 1-propanol prior to spectrophotometry at 571 nm. Beer's law was obeyed in the range of 2-230 ng mL(-1) of fenitrothion with relative standard deviation and recovery in the ranges of 0.9-5.1% and 97.2-100.0%, respectively. Selectivity of the method was evaluated, and the method was successfully applied to the determination of fenitrothion in various water, soil, urine and human plasma samples., (Crown Copyright © 2012. Published by Elsevier B.V. All rights reserved.)

A unique, efficient, highly sensitive and selective fluorescent chemosensor for fenitrothion has been reported for the first time using per-6-amino-β-cyclodextrin:Eu(III) complex. Among the various pesticides, the sensitivity response is found to be in the order, fenitrothion>>>quinalphos>methylparathion>parathion>methylparaoxon>paraoxon>fenchlorphos>profenofos>malathion. A detection limit as low as 1 × 10(-12)M for fenitrothion sensing is realized with a 2.4% relative standard deviation (RSD) of three consecutive runs. The per-6-amino-β-cyclodextrin:Eu(III):pesticide complexes and their sensing mechanism are evidenced from emission, NMR, FT-IR, binding constant measurement, Job's plot, ICD spectra, ESI-MS, lifetime measurements and molecular modeling studies. The proposed sensing is a consequence of Absorption Energy Transfer Emission (AETE) process as a result of better encapsulation of fenitrothion inside the cavity of per-6-amino-β-cyclodextrin:Eu(III) complex. The remarkable sensitivity and selectivity of fenitrothion compared to other OPs, is attributed to a more deeper binding and tighter fit of fenitrothion inside the CD cavity, which is evident from binding constant values and molecular modeling studies. This tighter fit ensures the replacement of two coordinating water molecules on Eu(III) ion, which may have contributed to the more selective sensing of fenitrothion., (Copyright © 2012 Elsevier B.V. All rights reserved.)

Seeds of faba and soybeans were treated with dichlorvos (12 mg/kg) and fenitrothion (5 mg/kg) insecticides and stored for 30 weeks. The total internal residues of dichlorvos and fenitrothion amounted to about 69%, 73% and 67%, 74% in the applied doses in faba and soybeans, respectively. The pathological potential of dichlorvos and fenitrothion residues was studied by feeding mice for 90 days with the treated seeds. Parallel studies were conducted in two control groups. Liver and kidney were taken for histological examinations. The results of blood biochemistry are supported by the histopathological changes observed in the liver and kidney of treated mice. Dichlorvos and fenitrothion insecticides caused degenerative changes in the liver and kidney of mice. Changes were more intense in mice which were given beans treated with dichlorvos than in mice fed on beans treated with fenitrothion. The livers of both treated groups showed an abnormal size and shape of hepatic cells. The kidneys of treated mice showed tubular vascular degeneration and lumen dilatation in both groups as compared with the control group., (Copyright © 2012 Elsevier GmbH. All rights reserved.)

This study evaluates the toxic effects of five substances (atropine, fenitrothion, potassium cyanide, mercuric chloride and lead nitrate) on the yeast Saccharomyces cerevisiae. It describes a new biological toxicity test based on inhibition of S. cerevisiae viability and compares it with two standard toxicity tests based on Daphnia magna mobility inhibition (EN ISO 6341) and Vibrio fischeri bioluminiscence inhibition (EN ISO 11348-2). The new biological test -S. cerevisiae lethal test - is cheaper and 24 times faster than the D. magna test. The test speed is comparable with the V. fischeri test but the new test is more sensitive for some substances. The test indicates reliably the presence of all used toxicants in water in concentrations which are significantly lower than the concentration in toxic or lethal doses for man. Therefore, this new toxicity test could be proposed for rapid detection of toxic substances in water., (Copyright © 2012 Elsevier B.V. All rights reserved.)

A single-chain variable fragment (ScFv) complementary DNA (cDNA) library against fenitrothion was constructed, and ScFvs specific for fenitrothion were selected by ribosome display from the library. After three rounds of ribosome display, the ScFv genes were cloned into Escherichia coli for expression. The expressed ScFvs of 160 clones were analyzed by indirect enzyme-linked immunosorbent assay (ELISA). Of these, 40 clones produced antibodies with relatively high activity against fenitrothion, and 3 were selected for Biacore and ELISA analysis. These 3 antibodies-ScFv-AF50, ScFv-AF93, and ScFv-AF132-had IC(50) values of 1.6, 3.4, and 2.2 ng/ml, respectively. Cross-reactivity with other organophosphorus (OP) pesticides was below 0.1% except for parathion-methyl (≤2.8%). The IC(50) values and cross-reactivity were lower than achieved previously with polyclonal or monoclonal antibodies against fenitrothion. The equilibrium dissociation constant (K(D)) values determined by Biacore analysis were 4.56×10(-10)M for ScFv-AF50, 1.42×10(-9)M for ScFv-AF93, and 2.66×10(-10)M for ScFv-AF132. These results demonstrate that the ribosome display has great potential in selection of ScFvs against pesticides. Recoveries of fenitrothion from fortified rice and cucumber were in the range 80.6 to 108%, indicating that the ELISAs with the isolated ScFvs can accurately determine fenitrothion in food samples after the simple and rapid extraction procedure., (Copyright © 2011 Elsevier Inc. All rights reserved.)

The aim of this study was to evaluate the efficiency of microwave-assisted extraction (MAE) for the analysis of organophosphorus (OP) and pyrethroid (PYR) pesticides in green onions by GC/MS. We optimized MAE extraction solvent, temperature, and time by using a certified reference material. As a result, the concentrations of two OP and two PYR target pesticides obtained by MAE with acetonitrile at 110 degrees C for 10 min were in good agreement with certified concentrations and comparable to the results by homogenization used as reference extraction technique. When the recovery test, performed by spiking the target pesticides into blank samples (5.0 g), was carried out with our optimized MAE conditions, mean recoveries of 16 OP and 10 PYR pesticides were 72-108% for a 1.0 pg spiking level and 70-119% for a 0.2 microg level. These results were acceptable according to the validation guideline for testing method of agricultural chemicals in food by Ministry of Health, Labour, and Welfare in Japan. The results suggested that MAE can be used for the analysis of OP and PYR pesticides in green onions.

A survey of various pesticide contaminations was performed for water in Yanamune River flowing into Lake Biwa from 1988 to 2009. Ten pesticides (diazinon and fenitrothion as insecticides, iprobenfos and isoprothiolane as fungicides and chlornitrofen, thiobencarb, molinate, bromobutide, simetryne and pretilachlor as herbicides) were selected and concentration changes of the pesticides were evaluated based on their shipment amounts. Yearly maximum concentrations of eight of the pesticides in Yanamune River water were compared with their no observed effect concentration and their predicted no effect concentration values and initial ecological risk assessment was conducted for five pesticides (diazinon, fenitrothion, iprobenfos, isoprothiolane and thiobencarb) by their predicted no effect concentration values. All of the diazinon (0.01-0.28 μg/L) and fenitrothion (0.005-0.31 μg/L) concentrations from 1988 to 2007, the iprobenfos (2.7 and 2.4 μg/L) concentrations in 1988 and 1990 and the thiobencarb (0.24-2.7 μg/L) concentrations in 1988, 1992, 1993 and 1995 exceeded their predicted no effect concentration (PNEC) (0.00026, 0.00021, 1.0 and 0.17 μg/L) values.

We present a method based on monolitic spin column extraction and gas chromatography-mass spectrometry as an analytical method for screening diquat (DQ), paraquat (PQ), and fenitrothion in serum and urine. This method is useful for clinical and forensic toxicological analyses. Recovery of DQ, PQ, and fenitrothion from serum and urine, spiked at concentrations between 0.1, 2.5, 20, and 45 μg/ml, ranged from 51.3% to 106.1%. Relative standard deviation percentages were between 3.3% and 14.8%. Detection and quantitation limits for serum and urine were 0.025 and 0.05 μg/ml, respectively, for DQ, 0.1 and 0.1 μg/ml, respectively, for PQ, and 0.025 and 0.05 μg/ml, respectively, for fenitrothion. Therefore, these compounds can be detected and quantified in the case of acute poisoning.

A new and selective sorbent for molecularly imprinted solid-phase extraction (MISPE) was developed and applied for the determination of residues of fenitrothion (FNT) in tomatoes, using HPLC coupled to photodiode array detection (HPLC-DAD). Using FNT as the template molecule, methacrylic acid as the functional monomer, ethylene glycol dimethacrylate as the cross-linker, toluene as the porogenic solvent, and bulk polymerization as the synthetic method, a molecularly imprinted polymer (MIP) was synthesized. In order to choose the medium which promotes the best molecular recognition of FNT by the MIP, the adsorption of FNT by the MIP was studied in different media containing acetonitrile and toluene. Besides FNT, three structurally related compounds were used to evaluate the selectivity of the FNT-molecularly imprinted polymer. The MIP exhibited the highest selective rebinding to FNT. The method developed was validated, using fortified blank tomato samples. The extraction efficiency was 96%. The limits of detection and quantitation were 0.050 and 0.130 microg g(-1), respectively. The intra-day precision was 5.9% and the inter-day precision 8.1%. The accuracy was higher than 89% for a concentration level around the maximum residue limit of 0.5 microg g(-1).