Hapten prediction, monoclonal antibody preparation, and development of an immunochromatographic assay for the detection of fenamiphos.

The ameliorative effect of Naringenin on fenamiphos induced hepatotoxicity and nephrotoxicity in a rat model: Oxidative stress, inflammatory markers, biochemical, histopathological, immunohistochemical and electron microscopy study

Surface engineering of samarium stannate–polyimide via laser-assisted graphenization for enhanced electrochemical detection of fenamiphos

Molecularly imprinted polymer film loaded on the metal–organic framework with improved performance using stabilized gold-doped graphite carbon nitride nanosheets for the single-step detection of Fenamiphos

ABSTRACT In this study, we proposed a new electroanalytical methodology using a boron-doped diamond electrode (BDD), associated with factorial design for simultaneous and selective determination of bentazon (BTZ) and fenamiphos (FNP). These pesticides are frequently combined for different crops and have overlapping oxidation potential signals (1.04 V and 1.13 V for BTZ and FNP, respectively). Thus, to enable simultaneous determination we used a 33 full factorial design with three parameters at three levels, using the D-optimal design. The optimised square wave voltammetry parameters were pH 4.0, frequency of 200 s−1, pulse amplitude of 10 mV, and scan increment of 4.0 mV. These parameters were used for the construction of calibration curves, which showed linear ranges of 9.90 µmol L−1 to 91.0 µmol L−1 for BTZ and 4.95 µmol L−1 to 69.0 µmol L−1 for FNP. The limits of detection (LOD) and quantification (LOQ) were 0.38 µmol L−1 and 1.27 µmol L−1 for BTZ, and 1.50 µmol L−1 and 4.98 µmol L−1 for FNP. The performance of the method was evaluated using a natural water sample collected from a supply dam. The recovery values were 117.5% for BTZ and 88.6% for FNP. The results show that the developed method is suitable for the simultaneous determination of both pesticides in samples from natural water.

A novel detection method for organophosphorus insecticide fenamiphos: Molecularly imprinted electrochemical sensor based on core-shell Co3O4@MOF-74 nanocomposite

Risk assessment of the chiral pesticide fenamiphos in a human model: Cytochrome P450 phenotyping and inhibition studies

Abstract In this study, electrochemically reduced graphene oxide (ERGO) was used for the preparation of a screen‐printed modified electrode and applied for the voltammetric determination of fenamiphos (FNP) in tomato samples. Graphene oxide (GO) used for sensor construction was prepared according to an improved Hummers method and characterized by XRD, TEM, and FTIR, which confirmed the nanomaterial obtention. The ERGO formation was carried out from the electrodeposition by cyclic voltammetry, at 50 mV s−1 in the potential range of 0.0 to −1.5 V, during 50 cycles. ERGO‐SPE was used in the evaluation of the voltammetric behavior of FNP. The ERGO‐SPE proposed presented excellent electrochemical performance towards FNP oxidation, promoting an enhance on the anodic peak current and a decrease of peak potential. Under optimized conditions, it was possible to construct an analytical curve, using square wave voltammetry, with a linear region of 0.25 to 25.0 μM, with calculated limits of detection and quantification of 0.067 and 0.22 μM. From this, it was possible to analyze FNP in fortified tomato samples at three concentration levels, which showed recoveries values varying between 82 and 102 %. The ERGO‐SPE device proved useful in determining FNP, where the effect of the electrodeposition of the GO promoted a significant increase in the employability of the printed electrode.

Sustainable alternatives to 1,3-dichloropropene for controlling root-knot nematodes and fungal pathogens in melon crops in Mediterranean soils: Efficacy and effects on soil quality

A simple, rapid, and sensitive electrochemical method was developed for the determination of the organophosphate insecticide fenamiphos (FNP) and its main metabolite fenamiphos sulfoxide (FNX). The electrochemical behaviour was investigated by cyclic voltammetry and differential pulse voltammetry on a bare glassy carbon electrode. An oxidation peak was obtained for FNP and FNX at a bare glassy carbon electrode. The anodic peak showed irreversible behaviour and a mechanism of reaction at the electrode surface based on a mixed adsorption and diffusion controlled reaction is suggested. The obtained percentage of recovery showed good agreement compared to those reference values when GC–MS was used as a reference method.

In-line coupling of an achiral-chiral column to investigate the enantioselective in vitro metabolism of the pesticide Fenamiphos by human liver microsomes

Comparative Efficacy of Different Approaches to Manage Meloidogyne Incognita on Green Beans A greenhouse study was conducted to compare the relative efficacy of different approaches to manageMeloidogyne incognita on green beans. These approaches included: chemical (fumigant, nonfumigant, seed dressing, and seed dip), biological (the egg-parasitic fungus, Paecilomyces lilacinus, and the mycorrhyzal fungus Glomus sp.), physical (soil solarization), and cultural practices (chicken litter, and urea). In total, nine different control materials and methods of applications were compared. Two important parameters were considered: plant response (plant growth and root galling), and nematode reproduction (production of eggs and the reproduction factor Rf). Results showed that the organic fertilizer, chicken litter, has severely affected the growth or survival of the seedlings. Therefore, this treatment was removed from the evaluation test. All other treatments were found to be effective against the nematode, but with different levels of efficacy. The eight treatments decreased (38.9-99.8%) root galling, increased plant growth and suppressed nematode reproduction. Based on three important criteria, namely: gall index (GI), egg mass index (EMI), and reproduction factor (RF), the tested materials and methods were categorized into three groups according to their relative control efficacy under our test conditions. These three groups were: 1) the relatively high effective group (GI=1.0-1.4, Rf=0.07-0.01) included: the fumigant dazomet, the non-fumigant fenamiphos, soil solarization, and seed-dip with fenamiphos; 2) the relatively moderate effective group (GI=3.4-4.0, Rf=0.24-0.60) included: seed dressing with fenamiphos, and urea; and 3) the relatively less effective group (GI=5.0, Rf=32.2-37.2) included: Paecilomyces lilacinus and Glomus sp....

Abstract This study is aimed to develop an electroanalytical methodology using a boron‐doped diamond electrode (BDD) associated with experimental design in order to determine simultaneously and selectively carbendazin (CBZ) and fenamiphos (FNP) pesticides. In previous studies oxidation peaks were observed at 1.10 V (CBZ) and 1.20 V (FNP), respectively, with characteristics of irreversible processes controlled by diffusion of species (in pH 2.0 (CBZ) and pH 3.5 (FNP)) using a BR buffer 0.1 mol L−1 as support electrolyte. The differences between the potentials for both pesticides, (about 100 mV) indicate the possibility of selective determination of FNP and CBZ. However, employing an equimolar mixture of analytes, the peaks overlap to form a single oxidation peak. Thus, we used a 34 full factorial design with four parameters to be analyzed in three levels, in order to obtain the optimized parameters for the separation of the peaks. The best separation conditions were pH 5.0, square wave frequency of 300 s−1, pulse amplitude of 10 mV and scan increment of 2 mV. These parameters were used to obtain the calibration curves of CBZ and FNP. For CBZ the analytical curve was obtained in the concentration range of 4.95×10−6 to 6.90×10−5 mol L−1 with good sensitivity and linearity (0.175 A/mol L−1 and 0.999, respectively). The limits of detection (LOD) and quantification (LOQ) were 1.6×10−6 mol L−1 and 5.5×10−6 mol L−1, respectively. For FNP the linear concentration interval was 4.95×10−6 to 3.67×10−5 mol L−1, with a sensitivity of 0,207 A/mol L−1 and linearity of 0.996. The LOD and LOQ were 4.1×10−6 mol L−1 and 13.7×10−6 mol L−1, respectively. Using these experimental conditions it was possible to separate the oxidation peaks of CBZ (Ep=1.08 V) and FNP (Ep=1.23 V). The electroanlytical method was applied in lemon juice samples. The recovery values were 110.0 % and 92.5 % for CBZ and FNP, respectively. The results showed that the developed method is suitable for application in foodstuff samples.

The photocatalytic degradation of the organophosphorus fenamiphos (FN) was studied using titanium dioxide as a photocatalyst and 365 nm as an excitation wavelength. Under our experimental conditions and in aerated solutions, the irradiation in the presence of TiO2 P25 (1.0 g L−1) permitted the evaluation of the half lifetime to 9.5 minutes. Laser flash photolysis experiments showed the formation of an initial species owing to the attack of the hydroxyl radical on FN. It was identified as the adduct OH•-FN. The second order rate constant for its formation was evaluated to 7.3×109 moL−1 L s−1. All the products are formed via the formation of such transient intermediate. They were identified by means of HPLC/MS using electrospray in positive mode (ESI+). Two main processes are responsible for FN photocatalytic transformation: (i) hydroxylation on the aromatic structure and (ii) the scission of the C–O bond. A mechanistic scheme was proposed for the photocatalytic process of FN using titanium dioxide. An efficient mineralization was observed within 24 hours by using a suntest setup.

Electroanalytical determination of carbendazim and fenamiphos in natural waters using a diamond electrode

Isolation of soil bacteria able to hydrolyze both organophosphate and carbamate pesticides

Enantioselectivity in the environmental behavior and ecotoxicity of chiral pesticide is widely observed. However, the investigation of the enantioselective mechanisms remains limited. In this study, we used fenamiphos (FAP), an organophosphorus insecticide, to study enantioselectivity in toxicity to arthropods and the inhibition potential towards acetylcholinesterase (AChE) in the rat pheochromocytoma 12 (PC 12) cell line. Furthermore, we carried out molecular docking to help explain the mechanisms of enantioselective toxicity of FAP. The two enantiomers of FAP were successfully separated and identified as R-(+)-FAP and S-(-)-FAP. Toxicological assays revealed that R-(+)-FAP was 2.4-fold more toxic than S-(-)-FAP to Daphnia magna and approximately threefold more to PC12 cells. Based on molecular docking results, dynamic simulation shows that strong hydrophobic interactions and a key hydrogen bond can only exist between R-(+)-FAP and AChE, which helps explain the preference of R-(+) binding to AChE over that of the S-(-)-enantiomer, and supports our biological results. Our present study considers the impact of stereochemistry on ecotoxicological effects and, ultimately, on development of environmentally safe, insecticidally efficient pesticides.

Review of the existing MRLs for fenamiphos

Expression of esterase gene in yeast for organophosphates biodegradation

Organophosphorus compounds (OPs), such as nerve agents and a group of insecticides, irreversibly inhibit the enzyme acetylcholinesterase (AChE) by a rapid phosphorylation of the catalytic Ser203 residue. The formed AChE-OP conjugate subsequently undergoes an elimination reaction, termed aging, that results in an enzyme completely resistant to oxime-mediated reactivation by medical antidotes. In this study, we present crystal structures of the non-aged and aged complexes between Mus musculus AChE (mAChE) and the nerve agents sarin, VX, and diisopropyl fluorophosphate (DFP) and the OP-based insecticides methamidophos (MeP) and fenamiphos (FeP). Non-aged conjugates of MeP, sarin, and FeP and aged conjugates of MeP, sarin, and VX are very similar to the noninhibited apo conformation of AChE. A minor structural change in the side chain of His447 is observed in the non-aged conjugate of VX. In contrast, an extensive rearrangement of the acyl loop region (residues 287-299) is observed in the non-aged structure of DFP and in the aged structures of DFP and FeP. In the case of FeP, the relatively large substituents of the phosphorus atom are reorganized during aging, providing a structural support of an aging reaction that proceeds through a nucleophilic attack on the phosphorus atom. The FeP aging rate constant is 14 times lower than the corresponding constant for the structurally related OP insecticide MeP, suggesting that tight steric constraints of the acyl pocket loop preclude the formation of a trigonal bipyramidal intermediate.