Organophosphorus Pesticide Residues Research Articles

Application of solid-phase microextraction and LCMS/MS for the detection of pesticide residues

Aiming at the organophosphorus pesticide residues in tea, a method integrating solid-phase microextraction and liquid chromatography-mass spectrometry was investigated for the detection of organophosphorus pesticide residues in tea. Firstly, the conditions in the process were optimized; then the method was established to analyze the organophosphorus pesticides in tea; finally, the method feasibility was verified by using actual sample determination. In terms of the results, the standard curve correlation coefficients of the solid-phase microextraction and liquid chromatography-mass spectrometry methods used in the study were greater than 0.99, while the average recoveries ranged from 72 to 109% with the relative standard deviations (RSDs) of less than 9.0%. This indicates that the method has a good linear range, low detection limit and high recovery. In the application validation in real samples, the concentrations of organophosphorus pesticide residues in tea were within the safe range. The method was validated to be suitable for the monitoring and control of organophosphorus pesticide residues in tea with low cost and simplified sample preparation.

Deep eutectic solvent-based pressurized liquid extraction combined with dispersive liquid-liquid microextraction of organophosphorus pesticide residues in egg powder prior to high-performance liquid chromatography analysis.

Herein, a deep eutectic solvent (DES)-based miniaturized pressurized liquid extraction in combination with DES-based dispersive liquid-liquid microextraction (DLLME) was developed for the extraction of organophosphorus pesticides (parathion-methyl, triazophos, parathion, diazinon, and phoxim) from egg powder samples prior to their analysis by a high-performance liquid chromatography-diode array detector. In this work, first, the analytes' extraction was done by a pressurized liquid phase extraction for effective extraction of the analytes from the solid matrix, and then they were concentrated on a DLLME for more concentration of the analytes to reach low limits of detections. The use of DESs was done in both steps to omit the use of toxic organic solvents. Satisfactory results including high extraction recoveries (74-90%), great repeatability (relative standard deviations equal or less than 4.3% and 5.3% for intra- and inter-day precisions), and low limits of detection (0.11-0.29ng/g) and quantification (0.38-0.98ng/g) were attained under the optimum conditions. Lastly, the suggested approach was utilized for the determination of the studied pesticides in various egg powder samples marketed in Tabriz, Iran.

New insights to improve the storage stability of pesticide residues in analytical samples

The factors affecting the storage stability of dichlorvos, malathion, diazinon and chlorpyrifos in celery were studied, and the mechanism of improvement of storage stability was explained. Residues of dichlorvos and malathion may be more stable in homogenized celery than in coarse form. The important role of storage form may be attributed to the difference of enzymes in the matrix. The results showed that POD activity in homogenized celery was lower than that in coarse one, and pesticide residues were more stable in homogenate. The interaction between POD and pesticide molecules was confirmed by computational chemistry method. Moreover, exogenous metal ions (Fe3+ and Al3+) could significantly inhibit POD activity and improve stability of malathion, dichlorvos, and chlorpyrifos. When the concentration of ions increased to 40 mmol/L, the residue remaining of dichlorvos and malathion increased significantly. Instead, the significant reduction in diazinon was found because it was more susceptible to changes in pH, where acidic conditions were not conducive to its stable presence. Except in a few cases, the addition of metal ions can directly or indirectly improve storage stability of organophosphorus pesticide residues by inhibiting enzyme activity.

Degradation and detection of organophosphorus pesticides based on peptides and MXene-peptide composite materials.

Safety problems caused by organophosphorus pesticide (OP) residues are constantly occurring, so the development of new methods for the degradation and detection of OPs is of great scientific significance. In the present study, β-sheet peptides and β-hairpin peptides for catalyzing the hydrolysis of OPs were designed and synthesized. The peptide sequences with the highest hydrolytic activity (EHSGGVTVDPPLTVEHSAG) were screened by investigating the effect of the location of the active sites of the peptide and the peptide's structure on the degradation of OPs. In addition, the relationship between the peptides' conformation and hydrolytic activity was further analyzed based on density functional theory calculations. The noncovalent interactions of the peptides with the OPs and the electrostatic potential on the molecular surface and molecular docking properties were also investigated. It was found that peptides with approximate active amino acids consisting of the catalytic triad and with the hairpin structure had enhanced hydrolytic activity toward the hydrolysis of OPs. To develop an electrochemical sensor technique to detect OPs, the conductive MXene (Ti3C2) material was first immobilized with a caffeic acid monolayer via enediol-metal complex chemistry and then bound with the β-hairpin peptide (EHSGGVTVDPPLTVEHSAG) via carboxy-amine condensation chemistry between the -COOH of caffeic acid and the -NH2 of the peptide to prepare a MXene-peptide composite. Then, the prepared composite was modified on the surface of a glassy carbon electrode to construct an electrochemical sensor for the detection of OPs. The developed technique could be used to monitor OPs within 15 min with a two orders of linear working range and with a detection limit of 0.15 μM. Meanwhile, the sensor showed good reliability for the detection of OPs in real vegetables.

An Integrated Platform and Method for Rapid High-Throughput Quantitative Detection of Organophosphorus Pesticide Residues

An Integrated Platform and Method for Rapid High-Throughput Quantitative Detection of Organophosphorus Pesticide Residues

Molecularly imprinted polymer-coated paper for the selective extraction of organophosphorus pesticides from fruits, vegetables, and cereal grains

Biodegradable molecularly imprinted polymer-coated paper (MIP@paper) was effectively produced by polymerization using azinphos-methyl as a template molecule, terephthalic acid as a functional monomer, ethylene glycol dimethacrylate as a cross-linker, and aqueous ethanol as a green porogenic solvent. The material was subsequently composited onto cellulose paper, which served as the natural substrate, by dip coating with the aid of chitosan and citric acid natural adhesive. The properties, such as static and dynamic adsorption, selectivity, and reusability, were assessed. At rapid adsorption equilibrium (10 min), the MIP@paper had a high adsorption capacity in the range of 2.5–3.7 mg g−1 and good recognition with imprinting factors up to 2.1. In addition, the proposed MIP@paper was utilized efficiently as a sorbent for dispersive solid phase extraction (d-SPE) of eight organophosphorus pesticides (OPPs) prior to high-performance liquid chromatography (HPLC) analysis. The d-SPE-HPLC method displayed low detection limits of 1.2–4.5 μg kg−1 and significant enrichment factors (up to 320-fold). The proposed method was effectively applied for the determination of OPP residues in agricultural products, including fruits, vegetables, and cereal grains, with satisfactory spiked recoveries (80.1–119.1 %). Thus, the MIP@paper material provided a selective and environmentally favorable method for extracting and determining organophosphorus pesticides.

Enzyme-mediated Ru@UiO-66@MnO2 NSs/thiamine-based ratiometric fluorescence sensor for visual detection of organophosphorus pesticide residues.

In view of the potential hazards of organophosphorus pesticides (OPs), this paper constructed a ratiometric fluorescent probe utilizing a functionalized metal-organic framework to detect OPs. Ru(bpy)3Cl2 was encapsulated inside UiO-66 as a reference signal, and MnO2 nanosheets (MnO2 NSs) were grown on the surface to obtain Ru@UiO-66@MnO2 NSs. Acetylcholinesterase catalyzed the decomposition of acetylcholine into reductive thiocholine, which consumed MnO2 NSs, thus restoring the Ru@UiO-66 fluorescence. Due to the enzymatic inhibition of OPs and the redox reaction between MnO2 NSs and thiamine, this probe emitted blue fluorescence in the presence of OPs. The probe achieved linear responses to dichlorvos and chlorpyrifos with LODs of 9.99×10-6 μg mL-1 and 9.99×10-5 μg mL-1. The probe exhibited a satisfactory recovery rate for OPs in green tea. Furthermore, a hydrogel detection platform was developed by embedding the probe into sodium alginate. Overall, this work provides a visual approach to detect OPs in agricultural products.

ZnO-rGO-based electrochemical biosensor for the detection of organophosphorus pesticides

The accurate determination of organophosphorus pesticide residues is of great importance for human disease monitoring and environmental safety. Numerous detection methods exist, among which sensitive monitoring of organophosphorus compounds using electrochemical sensors has gradually become a research hotspot. This paper used acetylcholinesterase (AChE) as an indicator anchored on a zinc oxide-reduced graphene oxide (ZnO-rGO) composite rich in active sites, in which green non-toxic zinc oxide (ZnO) nanomaterials were uniformly distributed on the reduced graphene for rapid detection of organophosphorus. The effects of different ratios of ZnO to reduced graphene on the performance of ZnO-rGO nanocomposites were investigated. The AChE/ZnO-rGO biosensor detects organophosphorus by electrochemical inhibition of acetylcholinesterase in the presence of organophosphorus. The developed electrochemical biosensor has high selectivity and good linearity, and the ZnO-rGO nanocomposite as a matrix for immobilization of acetylcholinesterase and detection of organophosphorus has the potential for highly sensitive pesticide detection.

Portable organophosphorus pesticide detection device based on controllable microfluidic and luminol composite nanofibers

Excessive organophosphorus pesticide residues in food are a serious threat to human health, it is very urgent to develop a portable, low-cost, and high precision pesticide residue detection device to achieve rapid detection of organophosphorus pesticide residues. In this study, a portable organophosphorus pesticide detection device equipped with microfluidic and luminol composite nanofibers was developed. The microfluidic chip was designed and optimized by a combine of mathematical model and multi-physics coupling simulation. The luminol particles were solidly loaded on polyacrylonitrile (PAN) electrospinning film through electrospinning method to achieve efficient utilization of microfluidic chips and luminol fluorescent reagents. The influence of the mass fraction of luminol particle on the microstructure of electrospinning film was analyzed, and the optimal mass fraction was determined by measuring the fluorescent stability and fluorescent intensity. The electrospinning film and the microfluidic chip was loaded to an independently developed portable organophosphorus pesticide detection device, whose detection limit can reach 0.035 mg/L and the average detection time can reach 30 s. The portable organophosphorus pesticide detection device shows high stability, high detection accuracy and efficiency, which can be widely adopted in the detection of organophosphorus pesticides.

Photothermal effect-enhanced peroxidase-like performance for sensitive detection of organophosphorus pesticides on a visual test strip

Pesticides pose a serious risk to public health, even in trace amounts. The sensitive, rapid, visual, and on-site detection of pesticides in a real sample remains a challenge. Herein, we report a visual and rapid organophosphorus pesticide (OP) sensing device with excellent sensitivity, ease of application, and specificity based on a photothermal effect-based peroxidase (POD) mimetic. The ultrathin MIL-101-NH2(Fe) (Fe-MOF) shell-coated Au nanobipyramide (NBP) not only possesses POD-like activity, but also exhibits excellent photothermal effect under near-infrared (NIR) light. The results reveal that the excellent photo-to-thermal conversion of the Au NBPs can rapidly heat the MIL-101-NH2(Fe) shell, which subsequently induces a markedly enhanced POD-like activity. Using paraoxon-ethyl as model OP, the combination of the OP inhibition effect on the biocatalytic activity of acetylcholinesterase with the inhibition effect of thiocholine on the colorimetric assays of the POD-mimicking Fe-MOF leads to a significant improved selectivity for OP sensing. In particular, the NIR light irradiation increased the OP detection sensitivity by 100 times. Importantly, based on this detection strategy, a visual test strip with high sensitivity was developed and enabled real-time detection through a simple color analysis software on a smartphone. The successful detection of OP residues in fruit peel using this test strip further confirmed its application potential in real sample analysis.

Degradation of selected organophosphorus pesticide residues and their pre harvest interval determination in hyacinth bean grown commercially in Bangladesh

The consumers are very much concerned about food safety. To ensure safe food for the consumers, it is essential to follow the pre harvest interval (PHI) of pesticides. Therefore, in order to ascertain the pre-harvest interval of fenitrothion and diazinon in hyacinth bean in the environmental conditions of Bangladesh, this study was started. The chosen organophosphorus insecticides (fenitrothion and diazinon) were sprayed with the recommended dose (1.5 ml/L of water) in a field trial at the Entomology Division of BARI, Gazipur. At 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, and 12 days after spray (DAS), samples were taken. The Gas chromatography (GC) with a Flame Thermionic Detector (FTD) was used to quantify the residues after the samples were prepared using a modified Quick, Easy, Cheap, Effective, Rugged and Safe (QuEChERS) extraction method. Fenitrothion residue was found up to 8 DAS, and at 7 DAS (0.018 mg/Kg), the level of residue was above the MRL. At 8 DAS, the fenitrothion residue was 0.007 mg/kg, which was below MRL. Pre-harvest interval (PHI) for fenitrothion was determined at 8 DAS, and no residue was found after 9 DAS. Diazinon residue was found up to 9 DAS, with the level of residue above the MRL at 8 DAS (0.016 mg/Kg). At 9 DAS, the diazinon residue was 0.007 mg/kg, which was below MRL. Pre-harvest interval (PHI) was determined for diazinon at 9 DAS, and as of 10 DAS, no residue was found. Asian Australas. J. Biosci. Biotechnol. 2023, 8 (2), 30-37

Development of a fluorescent sensor based on TPE-Fc and GSH-AuNCs for the detection of organophosphorus pesticide residues in vegetables

A novel dual-signal fluorescent sensor was developed for detecting organophosphorus pesticides (OPs). It relies on the catalytic activities of acetylcholinesterase (AChE) and choline oxidase (ChOx) to generate hydrogen peroxide (H2O2) through the conversion of acetylcholine (ACh) to choline·H2O2 then oxidizes ferrocene-modified tetraphenylethylene (TPE-Fc) to its oxidized state (TPE-Fc+), resulting in enhanced cyan fluorescence due to aggregation. Simultaneously, ferrocene oxidation generates hydroxyl radicals (•OH), causing a decrease in orange fluorescence of glutathione-synthesized gold nanoclusters (GSH-AuNCs). The presence of OPs restricts AChE activity, reducing H2O2 production. Increasing OPs concentration leads to decreased cyan fluorescence and increased orange fluorescence, enabling visual OPs detection. The sensor has a linear dynamic range of 10–2000 ng/mL with a detection limit of 2.05 ng/mL. Smartphone-based color identification and a WeChat mini program were utilized for rapid OPs analysis with successful outcomes.

Application of MNPs/ODA-SBA-15 composites in pretreatment of organophosphorus pesticide residues in green leafy vegetables

Application of MNPs/ODA-SBA-15 composites in pretreatment of organophosphorus pesticide residues in green leafy vegetables

Quantitative determination of organophosphorus, pyrethroid, and dithiolane pesticide residues in brown rice using supercritical fluid extraction and liquid chromatography-tandem mass spectrometry.

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. In this study, as analytical method using SFE was optimized and validated by testing the incurred and fortified brown rice samples with organophosphorus, pyrethroid, and dithiolane pesticides. 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. In the test on the incurred samples, optimized SFE-to-SLE analytical values (CSFE/CSLE) were in 99.2-100.1%, with RSD lower than 3%. In contrast, the analytical-to-spiked concentrations in the tests on the fortified samples were in 96.4-105.0%, with RSD lower than 8.8%. These results indicate that the proposed SFE method, which is well validated with the incurred brown rice sample, is useful for determining organophosphorus, pyrethroid, and dithiolane pesticide residues in brown rice. The proposed SFE method satisfies EU and Japanese maximum residue limits. The consumption of solvent can be reduced to one-fourth of that of SLE using the proposed SFE method.

Enzyme-targeted near-infrared fluorescent probe for organophosphorus pesticide residue detection.

Pesticide residues significantly affect food safety and harmhuman health. In this work, a series of near-infrared fluorescent probes were designed and developed by acylating the hydroxyl group of the hemicyanine skeleton with aquenching moiety for monitoring the presence of organophosphorus pesticides in food and live cells. The carboxylic ester bond on the probe was hydrolyzed catalyticallyin the presence of carboxylesterase and thereby the fluorophore was releasedwith near-infrared emission. Notably, the proposed probe 1 exhibited excellent sensitivity against organophosphorus based on the carboxylesterase inhibition mechanism and the detection limit for isocarbophos achieved 0.1734μg/L in the fresh vegetable sample. More importantly, probe 1 allowed for situ visualization of organophosphorus in live cells and bacteria, meaning great potential for tracking the organophosphorus in biological systems. Consequently, this study presents a promising strategy for tracking pesticide residues in food and biological systems.

Monitoring and risk assessment of organophosphorus pesticide residues in surface and drinking water in some Egyptian governorates

Monitoring and risk assessment of organophosphorus pesticide residues in surface and drinking water in some Egyptian governorates

Investigation of Organophosphorus and Carbamate Pesticide Residues in Tobacco Produced and Imported in Iran in 1400

Investigation of Organophosphorus and Carbamate Pesticide Residues in Tobacco Produced and Imported in Iran in 1400

Preparation of Fe3O4@UiO-66(Zr)@Ag NPs core-shell-satellite structured SERS substrate for trace detection of organophosphorus pesticides residues.

Surface-enhanced Raman spectroscopy (SERS) technology has been revived and developed with the introduction of metal-organic frameworks (MOFs), while more valuable properties of MOFs for SERS substrates remain largely unexplored. This work constructed a new SERS substrate Fe3O4@UiO-66(Zr)@Ag nanoparticles (FUAs) with excellent SERS detection sensitivity, uniformity, reproducibility and stability, exhibiting a high Raman enhancement factor (5.62×106), low limit of detection (LOD, 2.11×10-11 M) and RSD (12.41%) for 4-NBT, and maintaining 81% SERS activity within 60days. The FUAs took full advantage of the strong affinity of UiO-66(Zr) for organophosphorus pesticides (OPs) to realize trace OPs detection. The LODs of phoxim, triazophos and methyl parathion in apple juice were 0.041, 0.021 and 0.0031mg/L, respectively, with good linearities ranging from 0.02 or 0.1-50mg/L, meeting the requirements of the food control standards, indicating that the potentials and prospects of the FUAs SERS substrate for trace detecting OPs in foods.

Enzymatic reaction modulated hydride generation of arsenic for parathion-methyl monitoring in traditional Chinese medicine by atomic fluorescence spectrometry

In the production of traditional Chinese medicine (TCM), the frequent use of organophosphorus pesticides (OPs) will lead to a certain residue and affect the quality of TCM. Therefore, the development of simple and rapid methods for OPs residue monitoring is of great significance for the quality control and evaluation of TCM. In this work, a novel method was developed for the indirect determination of parathion-methyl (PM) residue in TCM by hydride generation atomic fluorescence spectrometry (HG-AFS) based on enzyme modulation. The acetylthiocholine (ATCh) can be hydrolyzed by butyrylcholinesterase (BChE) to produce thiocholine (TCh), which contains − SH that can interact with As(III) and inhibits its HG procedure, further reducing its AFS signal. However, OPs like PM can inhibit the activity of BChE to restore the AFS signal. Therefore, the indirect analysis of PM can be achieved by detecting As(III). A low limit of detection (LOD) of 0.043 μg mL−1 and a relative standard deviation (RSD) of 0.5% were obtained, respectively. The proposed method was successfully applied for the analysis of PM residue in 6 kinds of TCMs commonly used in clinical practice. This present strategy offers a unique alternative for OPs assay with high sensitivity, selectivity, and simple operation.

Highly defective copper-based metal-organic frameworks for the efficient adsorption and detection of organophosphorus pesticides: An experimental and computational investigation

Organophosphorus pesticide (OP) residues pose a serious threat to human health, motivating the search for novel adsorbents and detection methods. Herein, defective copper-based metal organic frameworks (Cu-MOFs) were synthesized by the reaction of Cu2+ ions and 1,3,5-benzenetricarboxylate linkers in the presence of acetic acid. As the amount of acetic acid increased, the crystallization kinetics and morphology of the Cu-MOFs changed, leading to mesoporous Cu-MOFs with many large surface pores (defects). Adsorption studies of OPs revealed the defective Cu-MOFs showed faster pesticide adsorption kinetics and higher pesticide adsorption capacities. Density functional theory calculations showed that pesticide adsorption in the Cu-MOFs was mainly electrostatic. A dispersive solid phase extraction method was developed based on a defective Cu-MOF-6 for rapidly extracting pesticides from food samples. The method allowed pesticide detection over a wide linear concentration range, low limits of detection (0.0067–0.0164 µg L−1) and good recoveries in pesticide-spiked samples (81.03–109.55%).