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In this study, a capillary electrophoresis-based online immobilized acetylcholinesterase (AChE) microreactor was developed for the determination of organophosphorus pesticide (OPs) residues in six fruit and vegetable juice samples. AChE was immobilized on the inner wall at the inlet of the capillary via polydopamine (PDA) coating. The immobilized AChE activity and other kinetic parameters were evaluated by measuring the peak area of the product (thiocholine). The value of Michaelis-Menten constant (Km) was determined to be 3.11 mM, and the half-maximal inhibitory concentration (IC50) and inhibition constant (Ki) of tacrine on immobilized AChE were measured to be 0.46 μM and 0.27 μM, respectively. The activity of the immobilized AChE remained more than 85.0% of its initial immobilized enzyme activity after 30 runs. Then, the developed strategy was successfully applied to detect the acephate in six fruit and vegetable juice samples (apple, pear, peach, tomato, cucumber and lettuce juice) with a limit of detection (LOD) of 11.0 ng/mL. Results show that the recovery of spiked samples are in the range of 86.0-96.0% with RSD of less than 5.7%. Therefore, the proposed method is capable of achieving rapid analysis of acephate with simple operation when there are no other types of OPs in the real samples.

We evaluated fresh vegetables for residues of 18 pesticides with different chemical structures, including organochlorine pesticides, organophosphorus pesticides, carbamate pesticides, and pyrethroid pesticides and estimated that the potential health risks for consumers. A total of 313 samples were collected from 12 kinds of vegetables in Changchun, the capital of Jilin Province, People's Republic of China. Pesticide residues were analyzed by gas chromatography and mass spectrometry, and the curves were highly linear at 0.01 to 1.00 μg/mL (R2 ≥ 0.99). The mean recovery rate of the pesticides was 62 to 110% (relative standard deviation of5%). The limit of detection was 0.0001 to 0.0167 mg/kg, the limit of quantification was 0.0002 to 0.0556 mg/kg, and the overall detection rate was 28.43%. The prevalence of pesticides and of samples above the standard limit were highest in celery, the prevalence of pesticides was lowest in potatoes, and the prevalence of samples above the standard limit was lowest in cucumber. Three of the 18 pesticides were not detected: omethoate, chlorpyrifos, and fenvalerate. Among the 15 pesticides detected, the maximum risk factor of six (carbofuran, omethoate, phorate, dicofol, dimethoate, and dichlorvos) is1, indicating possible harm to human health. Residues of a single pesticide may not adversely affect a person's health, but multiple pesticide residues could present a health risk.

The residues of organophosphorus pesticide (OPs) on fruits and vegetables pose a threat to human health, so it is very meaningful to explore simple and fast detect methods for OPs residual. In this work, nickel ferrite/nickel oxide nanoparticles co-loaded three-dimensional reduced graphene oxide (3DRGO-NiFe2O4/NiO NPs), as a new low cost nanocomposite, was prepared. Based on its high performance mimetic peroxidase activity, a colorimetric method for the detection of OPs has been developed. Dichlorvos was chosen as model compounds to evaluate the detection performance. The detection linear range for dichlorvos is from 50 μg/mL to 2.5 × 104 μg/mL with a detection limit of 10 μg/mL. Furthermore, a test paper can be developed based on the 3DRGO-NiFe2O4/NiO NPs for visual detection of dichlorvos, and the image information of the paper sensor can be converted into digital signal and quantitative detection by a smartphone. Notably, this method can also be used to detect dichlorvos in real samples, including vegetables and fruits. Thus, the developed naked assay holds great potential in simple, inexpensive and rapid detection of OPs in fruit and vegetable samples.

Organophosphosphorus pesticides (OPs) are widely used as insecticides in agriculture. Human exposure to OPs has been linked to adverse effects including poorer child neurodevelopment, reduced birth weight, altered serum hormone levels, and reduced semen quality. We measured six OP dialkyl phosphate (DAP) metabolites [three dimethyl alkylphosphates (DMs) and three diethyl alkylphosphates (DEs)] in urine samples collected two times during pregnancy (~13 and ~26 weeks gestation) from 594 women participating in the CHAMACOS birth cohort study and resided in an agricultural community in the United States (U.S.) between 1999 and 2000. Previous studies have shown these women have higher OP exposures compared with the general U.S. population. We examined bivariate associations between prenatal DAP metabolite levels and exposure determinants such as age, season, years living in the US, housing characteristics, fruit and vegetable consumption, occupation and residential proximity to agricultural fields. Final multivariable models indicated that season of urine collection was significantly associated (p0.01) with specific gravity-adjusted DM, DE and total DAP metabolites; samples collected in fall and winter had higher concentrations than those collected in spring-summer. Specific gravity-adjusted levels of DM and total DAP metabolites were significantly higher in women who had resided in the U.S. for 5 years or less (p0.05). Levels of DM metabolites also increased with daily fruit and vegetable servings (p0.01), and levels of DE metabolites were higher in residences with poorer housekeeping quality (p0.01) and in mothers that worked in agriculture (p0.05). These findings suggest that there are multiple determinants of OP exposure in pregnant women.

Bacillus amyloliquefaciens YP6, a plant growth promoting rhizobacteria, is capable of efficiently degrading a wide range of organophosphorus pesticides (OPs). Here, we report the complete genome sequence of this bacterium with a genome size of 4 009 619 bp, 4 210 protein-coding genes and an average GC content of 45.9%. Based on the genome sequence, several genes previously described as being involved in solubilizing-phosphorus, OPs-degradation, indole-3-acetic acid (IAA) and siderophores synthesis. Interestingly, compared with the genomes of B. amyloliquefaciens species, strain YP6 had larger genome size and the most protein-coding genes. Moreover, the four categories of “cell envelope biogenesis, outer membrane (M),” “translation, ribosomal structure and biogenesis (J),” “transcription (K),” and “signal transduction mechanisms (T)” were fewer. These differences may be related to extensive environmental adaptability of the genus B. amyloliquefaciens. These results expand the application potential of strain YP6 for environmental bioremediation, provide gene resources involved in OPs degradation for biotechnology and gene engineering, and contribute to provide insights into the relationship between microorganism and living environment.

With growing environmental and health concerns over persistent organic compounds such as organophosphates, regulatory bodies have imposed strict regulations for their use and monitoring in water bodies. Although conventional analytical tools exist for the detection of organophosphorus pesticides, new strategies need to be developed to fulfil the ASSURED (affordable, sensitive, specific, user-friendly, rapid, equipment-free and deliverable to end users) criteria of the World Health Organisation. One such strategy is to employ the ability of certain nanoparticles to mimic the enzymatic activity of natural enzymes to develop optical sensors. We show that the intrinsic peroxidase-mimic NanoZyme activity of tyrosine-capped silver nanoparticles (Ag-NanoZyme) can be exploited for highly specific and rapid detection of chlorpyrifos, an organophosphorus pesticide. The underlying working principle of the proposed aptasensor is based on the dynamic non-covalent interaction of the chlorpyrifos specific aptamer (Chl) with the NanoZyme (sensor probe) vs. the pesticide target (analyte). The incorporation of the Chl aptamer ensures high specificity leading to a colorimetric response specifically in the presence of chlorpyrifos, while the sensor remains unresponsive to other pesticides from organophosphate and non-organophosphate groups. The robustness of the sensor to work directly in environmental samples was established by evaluating its ability to detect chlorpyrifos in river water samples. The excellent recovery rates demonstrate the sensor robustness, while the simplicity, and rapid sensor response (2 min) to detect the presence of chlorpyrifos highlights the capabilities of the proposed colorimetric sensing system.

Using the data from the “Agro-product Quality and Safety Risk Monitoring Plan” of the Ministry of Agriculture of China between 2012 and 2016, acute and chronic risk assessments of cumulative exposure to organophosphorus pesticides (OPPs) through vegetable consumption were conducted. The concentrations of 19 OPPs were measured in a total of 75,655 vegetable samples from urban and rural sites located in 31 provinces and covering 95 vegetable raw agricultural commodities (RACs). The results showed that 4989 samples (6.59%) contained at least one OPP and that 615 samples (0.81%) contained various combinations of OPPs. From the multiexposure data, the cumulative exposure was estimated for 19 OPPs using an equivalence approach, where the contribution of each OPP was calculated according to its measured concentration and its relative potency factor (RPF) with respect to acetylcholinesterase (AChE) inhibition of the index compound methamidophos. The cumulative exposure levels of OPPs were compared across ten age and sex subpopulation groups of Chinese under lower boundary (LB) and upper boundary (UB) scenarios to handle left-censored residue data. The highest cumulative exposure level of OPPs was observed in the subpopulation of children aged 2–7 years under the UB scenario. The P99.9 and P97.5 exposure levels in different subpopulation groups under both LB and UB scenarios did not exceed the acute reference dose (ARfD) or chronic acceptable daily intake (ADI) of methamidophos, respectively. This study is the first to investigate the cumulative exposure of OPPs in relation to neurotoxic health risks in China on the national level.

A novel dual-mode analytical method by employing nanozyme was developed for the detection of organophosphorus pesticides (OPP) for the first time. The detection principle is that the pesticide could be hydrolyzed to para-nitrophenol (p-NP) in the presence of nanoceria as nanozyme. p-NP exhibits the bright yellow color, and its color intensity has a positive correlation with the pesticide concentration. Meanwhile, the characteristic absorption peak at 400 nm of p-NP increases gradually with the raised concentration of pesticide. Therefore, a dual-mode method including smartphone-based colorimetric and spectroscopic strategies was rationally developed. Herein, methyl-paraoxon was selected as the representative compound. Under the optimum conditions, the detection limits of both two strategies were calculated to be 0.42 μmol L−1. Finally, the present method was successfully applied in three edible medicinal plants (Semen nelumbinis, Semen Armeniacae Amarum, Rhizoma Dioscoreae). The present work offers a reliable and convenient approach for routine detection of pesticide based on two different detection mechanisms.

Passive sampling techniques have been considered robust tools for monitoring freely dissolved concentrations of contaminants in aquatic systems. However, few passive samplers are currently available for the simultaneous sampling of both hydrophilic and hydrophobic chemicals. In this study, we developed a novel passive sampler (a hydrophilic-lipophilic balance sorbent-embedded cellulose acetate membrane (HECAM)) for estimating the time-weighted average (TWA) concentrations of both hydrophilic and hydrophobic organic contaminants in water. In our laboratorial controlled dynamic experiments, the accumulation results of thirty-seven target chemicals (including organophosphorus flame retardants, phenols, estrogens, organophosphorus pesticides, and triazine herbicides) with a wide polarity range (1.44

The concentrations and compositions of organophosphorus flame retardants (OPFRs) in various heat preservation materials from different brands and types in China were investigated, as well as their OPFR burdens and emission amounts. The average concentrations of ΣOPFRs were 41.4 ± 10.2, (7.1 ± 4.0) × 104, and 56.3 ± 19.3 μg/g in phenolic foams (PF), polyurethane foams (PUR), and extruded polystyrene boards (XPS), respectively. OPFRs in the PUR materials were ∼3 orders of magnitude higher than those in the other two materials, suggesting that organophosphate esters were added as flame retardants (FRs) in the PUR materials. Obvious variations in the concentrations and compositions of OPFRs were discovered in those heat preservation materials due to their material types, brands, and fire-ratings, as well as contaminations. TCIPP was the most dominant OPFR with a range from 22.3 (in PF) to 6.73 × 104 (in PUR) μg/g, which emphasized that TCIPP was the most commonly used flame retardant additives in China. Based on the OPFR concentrations, OPFR emission rates, and application amounts of heat preservation materials, we calculated the total burdens of OPFRs in those materials and their emission amounts in China. The potential total burden of OPFRs in the completed new buildings of China in 2017 was estimated to be ∼(2.37 ± 1.11) × 104 t, while the total emission of OPFRs from those new materials was ∼3.19 ± 1.65 t/y. As significant sources of OPFRs, the heat preservation materials used in exterior or interior walls may pose potential health risks to humans.

Organophosphorus pesticides (OPs) are frequently for pest control in the agriculture industry. Accumulation of OPs is harmful to the environment and human health. Thus, facile and portable detection of organophosphorus pesticides is of great importance. Among these methods, the fluorescence assay holds the advantages of high sensitivity, simplicity, nondestructive properties. Conventional fluorophores have the drawbacks of poor photostability and low signal-to-noise ratio due to their aggregation-caused quenching drawbacks at high concentration or in the aggregate state. Aggregation-induced emission fluorogens (AIEgens) are one key to develop next-generation fluorescence sensor due to their high emission efficiency in the aggregated state. 1,2-bis[4-(3-sulfonatopropoxyl) phenyl]-1,2-diphenylethene (BSPOTPE) is a typical AIE molecule containing two hydroxyl group. In this study, a fluorescence sensor based on BSPOTPE-SiO2–MnO2 sandwich nanocomposites was fabricated. Thiocholine (TCh), which produced from acetylthiocholine(ATCh) by the hydrolysis of acetylcholinesterase (AChE), can “turn on” the fluorescence sensor. Based on the inhibition effect of OPs on AChE activity and the corresponding “turn off” effect on the fluorescence sensor, an AIE-based assay for OPs determination was developed. The fabricated sensor for paraoxon determination has a good linear relationship in the range of 1–100 μg/L and the LOD of 1 μg/L. Moreover, a simple, convenient fluorescence strip for visual semi-quantitative of OPs was fabricated, indicating this “on-off” fluorescent sensor is promising for on-site and infield detection.

Fluorescence polarization (FP) assays play an important role in the detection of chemical contaminants in food and environmental due to a number of key advantages since last century. In recent decades, FP assays have achieved great progress thanks to developments in materials science and labelling techniques. This comprehensive review provides the state of art in methods design, recognition elements, fluorophores, multi-targeted analysis, practical applications with real samples, and the challenges of deploying FP assays for the detection of chemical contaminants. These new information and insightful commentary of the review will be critically important to the development and innovation of next-generation FP assays.

This work reports a paintable electrode ink for on-site direct detection of parathion residuals from vegetable products. The electrode ink was mainly fabricated by silicon carbide and multi-walled carbon nanotubes and the resulted painted electrode was further stabilized by a layer of chitosan acting as a fixing glue. The painted electrode shows significant sensitivity for parathion with a detection limit of 20 ng mL−1. In on-site practice of real samples the painted electrode was successfully used to monitor the parathion residuals on some common local supermarket vegetables such as Chinese cabbage, sweet potato leaf and cucumber, with satisfied results of recoveries between 76.0% and 96.2%.

Dichlorvos (2,2-dichlorovinyl-dimethylphosphate), an organophosphorus pesticide used for indoor insect and livestock parasite control, is among the most common commercially available pesticides. However, there are significant concerns over its toxicity, especially due to its relative stability in water, soil, and air. Zebrafish, an important developmental model, has been used for studying the effects of toxic compounds. The aim of this study was to evaluate the exposure to dichlorvos at early life stages (1 h postfertilization - 7 days postfertilization) in the zebrafish and its toxicological effects during the development, through morphological (7 days postfertilization), locomotor and social behavior analysis (7, 14, 30, 70, and 120 days postfertilization). Dichlorvos (1, 5, and 10 mg/L) exposure reduced the body length and heartbeat rate at 7 days postfertilization (dpf), as well as the surface area of the eyes (5 and 10 mg/L). The avoidance behavior test showed a significant decrease in escape responses at 7 (1, 5, and 10 mg/L) and 14 (5 and 10 mg/L) dpf zebrafish. The evaluation of larval exploratory behavior showed a reduction in distance traveled, mean speed (1, 5, and 10 mg/L) and time mobile (10 mg/L) between control and dichlorvos groups. In addition, the analysis performed on adult animals showed that the changes in distance traveled and mean speed remained reduced in 30 (1, 5, and 10 mg/L) and 70 dpf (5 and 10 mg/L), recovering values similar to the control at 120 dpf. The social behavior of zebrafish was not altered by exposure to dichlorvos in the early stages of development. Thus, the exposure to organophosphorus compounds at early stages of development induces an increased susceptibility to behavioral and neuronal changes that could be associated with several neurodegenerative diseases.

The bioremoval of organphosphorus and bioremovalof fertility in soil using Rhodobacter sphaeroides (R. sphaeroides) in the treatedwastewater were investigated in this research. Organphosphorus was not degraded under control group. The treated wastewater containning R. sphaeroides degraded organphosphorus and remediated fertility. Interestingly, the organophosphorus acid hydrolase gene (opdA) was expressed after inoculation 24 h. Subsequently, the organophosphorus acid hydrolase were synthesized to degrade organphosphorus. The organphosphorus started to be degraded after inoculation 24 h. The organphosphorus as stimulus signal induced organophosphorus acid hydrolase gene (opdA) expression through signal transduction pathway. The induction and secretion of the organophosphorus acid hydrolase occured after 24 h in R. sphaeroides, which could be attributed to its characteristics as an ancient bacteria. Lack of organic matter in soil under the control treatment could not maintain R. sphaeroides growth for over 24 h. The residual organics in the wastewater provided sufficient carbon sources and energy for R. sphaeroides under three dosage groups. The new method completed the remediation of organphosphorus pollution, the improvement of soil fertility and soybean processing wastewater treatment simultaneously, and realized the resource reutilization of wastewater and R. sphaeroides as sludge.

Accidents related to pesticides have occurred with increasing frequency in recent years. One such accident, involving O,O–dimethyl phosphoramidothioate (DMPAT), which is an essential pesticide intermediate in the manufacture of organophosphorus pesticides, occurred in Taichung, Taiwan, in 2016. The results of thermogravimetric analyzer, differential scanning calorimetry, and vent sizing package 2 experiments revealed that the atmosphere, heating rate, and stirring conditions of DMPAT affect its thermal stability. Multiple thermokinetic methods were adopted to determine the values of thermal safety parameters. Through multiple linear regression, a reaction model of DMPAT was developed. The time to conversion limit and self-accelerating decomposition temperature were determined. The results of this study provide a reference for ensureing the thermal safety of DMPAT processing, use, storage, and transport and preventing thermal decomposition accidents.

Refereed/Peer-reviewed A sensitive assay was developed to evaluate inhibitory effects of aqueous solution on acetylcholinesterase (AChE) activity via measuring hydrolysis rates of acetylcholine (ACh) based on ultra-performance liquid chromatography–tandem mass spectrometry (UPLC-MS/MS). Upon having identified precursor ions and product ions of the ACh and its hydrolysis products choline (Ch), the separation chromatogram for these two analytes has been established using a 50 mm reverse-phase BEH Shield RP18 column. The total chromatographic separation time is 7 min; limits of detection (LODs) for ACh and Ch are 0.14 µg L−1 and 0.12 µg L−1, respectively. A simple method for inactivation of AChE and optimization of operational parameters were then sequentially performed. It was found that adjusting solution pH to 2.5 not only can terminate the enzymatic reaction but also solve band shifting and broadening caused by aqueous matrices in chromatographic separation during UPLC-MS/MS detection. Under conditions of 0.00075 U mL−1 AChE, initial concentration of ACh at 100 µg L−1 and 20 min observation time, IC50 values of the proposed assay for chlorpyrifos-oxon, diazoxon, malaoxon, methidathion oxon, omethoate and paraoxon were 3.5 nM, 16.8 nM, 2.4 nM, 6.8 nM, 270 nM and 36.9 nM, respectively. They are 4.5–51.9 times smaller than those reported in a LC-MS based method, and >120 times lower than those obtained by the traditional Ellman method. The results suggested that, the proposed assay significantly increases the sensitivity of commercial AChE. In addition, inhibition efficiencies of three surface waters, a groundwater and four commercial brands of bottled drinking water samples on AChE activity were firstly measured using this UPLC-MS/MS based method. These water samples were proved to have different inhibitory effects on AChE activity, and the inhibition efficiencies dependent on concentrations of dissolved organic carbon (DOC) but are independent of UV absorbance at 254 nm (UV254) values. These results indicate that the proposed method has advantages of high sensitivity over all other conventional methods. It may become a promising AChE inhibition assay for assessing toxicity of aqueous solution containing neurotoxicity contaminants such as organophosphorus pesticides (OPPs) at low levels, or used to evaluate potential inhibition effects of natural waters on AChE activity.

Organophosphorus pesticides (OPPs) are one of the most widely used types of pesticide that play an important role in the production process due to their effects on preventing pathogen infection and increasing yield. However, in the early development and application of OPPs, their toxicological effects and the issue of environmental pollution were not considered. With the long-term overuse of OPPs, their hazards to the ecological environment (including soil and water) and animal health have attracted increasing attention. Therefore, this review first clarified the classification, characteristics, applications of various OPPs, and the government's restriction requirements on various OPPs. Second, the toxicological effects and metabolic mechanisms of OPPs and their metabolites were introduced in organisms. Finally, the existing methods of degrading OPPs were summarized, and the challenges and further addressing strategy of OPPs in the sustainable development of agriculture, the environment, and ecology were prospected. However, methods to solve the environmental and ecological problems caused by OPPs from the three aspects of use source, use process, and degradation methods were proposed, which provided a theoretical basis for addressing the stability of the ecological environment and improving the structure of the pesticide industry in the future.

A novel deep eutectic solvents (DES) was successfully applied as an emulsifier in vortex assisted liquid-liquid microextraction (VALLME) coupled with gas chromatography-mass spectrometry for the determination of organophosphorus pesticides in honey and fruit samples. Based on the result of toxicity study, DES provides new opportunities for the safe delivery and application. The predominant parameters affecting extraction efficiency were thoroughly optimized and studied in detail. Under optimum parameters, the calibration curve was determined in the concentration range of 0.1 to 200 µgL-1 with excellent determination coefficients values of 0.9989 to 0.9999. Limit of detection and limit of quantification were found to be 0.01 - 0.09 µgL-1 and 0.03 - 0.2 µgL-1, respectively. Application of the developed method to honey and fruit samples gave acceptable recovery values 83 - 109% with relative standard deviation below than 9.5%. The suggested approach has also proven to be simple, cost-effective, rapid, and non-toxic in nature.

Organophosphorus pesticides (OPs) are widely used in pest control. The residual OPs can cause pollution to the environment and harm to the human body. Although OPs can inhibit the activity of acetylcholinesterase (AChE) and lead to neurological diseases, it also provides enlightenment for the development of a simple and sensitive method for the detection of OPs. Herein, we report a colorimetric sensor array using nanozymes (Fe-N-C nanozymes and Cu-N-C nanozymes) combined with natural enzymes to discriminate eight OPs (Iprobenfos (Ipr), Diazinon (Dia), Crotoxyphos (Cro), Bromophos ethyl (Bro), Dipterex (Dip), Chlorpyrifos methyl (Chl), Ethion (Eth), and Omethoate (Ome)) through a cascade reaction system. Surprisingly, eight OPs were successfully identified in tap water at 1 ng mL−1.

Pesticides are enormously used to control the pests in agriculture, industry and human premises. Agricultural production has been significantly increased with the help of pesticides but their uncontrolled and excessive use is polluting the environment, food, water and agricultural products. Presence of pesticides residues in food products and human milk is the alarming sign to set up stringent monitoring system and eradication remedies. Many advancements have been happened in recent years for the detection and quantification different pesticides in the various matrices. The present review article specifically focuses on the detection techniques for the organophosphorus pesticides. Organophosphorus pesticides are now a days hugely applied in agriculture after ban on many organochlorine pesticides and hence creating health complications. Visual or colorimetric detection of the pesticides using different nanostructures is considerably exploited for the onsite monitoring of organophosphorus pesticides. These advancements in pesticides detection are presented in detail along with brief overview of pesticides removal methodologies.

Nine organophosphorus pesticides (OPPs) were determined in environmental waters from different origins using in situ ionic liquid dispersive liquid microextraction (IL-DLLME). This preconcentration technique was coupled to gas chromatography-mass spectrometry (GC-MS) using microvial insert thermal desorption, an approach that uses a thermal desorption injector as sample introduction system. The parameters affecting both the microextraction and sample injection steps were optimized. The proposed method showed good precision, with RSD values ranging from 4.1 to 9.7%, accuracy with recoveries in the 85–118% range, and sensitivity with DLs ranging from 5 to 16 ng L−1.

Highlights • GPSD plasma was successfully applied to degrade OP residues from L. barbarum. • GPSD plasma exposure didn’t induce any changes in the fruit quality. • Electrical and optical characteristics of the plasma discharge were analysed. • The degradation efficiency of OP residues reached 99.55% and 96.83% at 10 kV. Abstract Pesticides are widely used in commercial goji Lycium barbarum cultivation to prevent damage of the delicate fruits by insects, potentially leading to insecticide and fungicide residues at levels dangerous to human health. In this study, removal of organophosphorus pesticide (OP) residues (i.e. omethoate and dichlorvos) from the surface of L. barbarum was conducted using a gas phase surface discharge (GPSD) plasma system. ICCD and GC-MS measurements showed that a homogeneous and uniform GPSD glow-like plasma could be achieved and the efficiency of OP residues degradation greatly depended on the applied voltage and plasma exposure time, with 99.55% and 96.83% efficiency recorded for omethoate and dichlorvos (DDVP), respectively after 30 min GPSD plasma exposure at the discharge voltage of 10 kV. FT-IR and chemical analysis of the intermediates produced during GPSD exposure revealed that the omethoate and DDVP molecules could be completely degraded into nontoxic species, at the appropriate dosage of GPSD plasma exposure, without compromising the quality of L. barbarum. Based on the experimental and simulation results, a mechanism of OP degradation attributed to energetic electrons and highly reactive species generated by GPSD plasma was proposed.

Alternative flame retardants (FRs) have now replaced legacy FRs (such as polybrominated diphenyl ethers, PBDEs), but little is known about their fate in the aquatic environment. In this study, a range of legacy FRs (n = 10) and alternative FRs, including halogenated FRs (HFRs, n = 32) and organophosphorus FRs (OPFRs, n = 19), were screened in water samples collected from 23 rivers covering the whole latitudinal range of Sweden. Of the 61 targeted FRs, 26 were detected in at least one of the river samples, with ΣFR concentrations ranging up to 170 ng L− 1 (mean 31 ± 45 ng L− 1). In general, higher concentrations and a larger variety of FRs were detected in southern Sweden (ΣFR = 60 ± 56 ng L− 1) compared with the north (ΣFR = 9.0 ± 16 ng L− 1). In the south, HFRs were dominant, constituting on average 59% of ∑ FRs, whereas in the north, OPFRs were dominant, constituting on average 82% of ∑ FRs. This difference was best explained by higher population density in the south. The total daily flux of FRs into the Baltic Sea was estimated to be ~ 31 kg and comprised mainly tetrabromobisphenol-A (TBBPA), 3,4,5,6-tetrabromophthalic anhydride (TEBP-Anh), and 2,4,6-tribromophenol (TBP). To the best of our knowledge, this is the first report of environmental occurrence of TEBP-Anh, which was detected in two rivers and is suggested to originate from airports located near the sampling sites.

The residue sample storage stability of three organophosphorus pesticides, dichlorvos, diazinon, and malathion, under different conditions was investigated. The storage conditions studied included storage time, temperature, and sample form. The addition of extra enzyme to the samples was also studied to investigate its effect on stability. It was found that malathion was more unstable than dichlorvos and diazinon, there was an over 70% loss in 90 days even at −20 °C in coarsely chopped form. The pesticide residues were more stable when the cucumber was in homogenate form than coarsely chopped. Furthermore, the addition of catalase increased the degradation of malathion, where there was more decomposition with increasing levels of catalase. However, there was no obvious relationship between degradation of dichlorvos and diazinon and catalase concentration. Overall, this study revealed factors that can be optimized to increase the storage stability of organophosphorus pesticides, where enzyme was one of the main influencing factors.

It is important to detect pesticides residues due to the concern over food safety. In this work, the burning ash of waste paper was used as carbon source to synthesize carbon dots (C-dots). The fluorescence of obtained C-dots could been turn off by Fe3+ which was from Fe2+ oxidized by H2O2, organophosphorus pesticides could effectively inhibit the production of H2O2 by destroying the acetylcholinesterase activity, so the fluorescence of C-dots hold turning on in the presence of organophosphorus pesticides. Based on above principle that the fluorescence intensity of C-dots was proportional to the pesticides concentration, take chlorpyrifos for example, a universal method for pesticides detection was established. The linear range was 0.01-1.0 μg/mL with detection limit of 3 ng/mL. The method was reliable and sensitive to actual samples. The imaging of chlorpyrifos on cabbages leaves indicated this method could be used for visualization detection of organophosphorus pesticides in vegetables.

The full understanding of the single and joint toxicity of a variety of organophosphorus (OP) pesticides is still unavailable, because of the extreme complex mechanism of action. This study established a systems-level approach based on systems toxicology to investigate OP pesticide toxicity by incorporating ADME/T properties, protein prediction, and network and pathway analysis. The results showed that most OP pesticides are highly toxic according to the ADME/T parameters, and can interact with significant receptor proteins to cooperatively lead to various diseases by the established OP pesticide -protein and protein-disease networks. Furthermore, the studies that multiple OP pesticides potentially act on the same receptor proteins and/or the functionally diverse proteins explained that multiple OP pesticides could mutually enhance toxicological synergy or additive on a molecular/systematic level. To the end, the integrated pathways revealed the mechanism of toxicity of the interaction of OP pesticides and elucidated the pathogenesis induced by OP pesticides. This study demonstrates a systems-level approach for investigating OP pesticide toxicity that can be further applied to risk assessments of various toxins, which is of significant interest to food security and environmental protection.

With graphitic carbon nitride (g-C3N4) as fluorescent probe, gold nanoparticles (AuNPs) as colorimetric probe, a simple, green, sensitive dual-signaling (fluorometric and colorimetric) detection method for organophosphorus pesticides (OPs) was first constructed. In this method, AuNPs were not only as the colorimetric probes but also as the fluorescent absorbers. The fluorescence of g-C3N4 can be effectively quenched by AuNPs through the inner filter effect. Acetylcholinesterase (AChE) can catalyze acetylcholine (ACh) to product thiocholine, which can result in the aggregation of AuNPs and fluorescent recovery, simultaneously accompanied by a color change from claret-red to blue. When the OPs were introduced, they can irreversibly inhibit the activity of AChE, thus preventing the aggregation of AuNPs and fluorescent recovery. As the typical example of OPs, chlorpyrifos was chosen as the target analyte to demonstrate the possibility of the proposed sensing system. Under the optimal conditions, the linear range of chlorpyrifos was 2.0 × 10−11 ∼ 6.0 × 10−9 M. Especially, this dual-readout assay was also successfully used for detection of OPs in real samples.

Organophosphorus pesticides are a class of the most important groups of insecticides and are widely applied to pest and plant diseases control in agriculture. The extensive application of organophosphorus pesticides can subsequently release organophosphorus pesticides into environment which may pose a seriously adverse impact to non-target organisms and humans. However, we could not ban organophosphorus pesticides at present as they are very efficient. Therefore, the new technique of degradation of organophosphorus pesticides must be studied. In this paper, a ternary copper Schiff base complex 2Cu(C14H8NO3Cl)(C12H8N2)·3CH3OH was synthesized and characterised by physico-chemical and spectroscopic methods. The degraded effects of 4 pesticides by the complex were investigated. The results showed that the degraded rates of every organophosphorus pesticide were increased. However, the effects of degradation were varied because of the different molecule structures of organophosphorus pesticides. Gas chromatography-mass spectrometry (GC–MS) and ion chromatography were used to analyze the degradation products by the complex, and then the catalytic mechanism of degradation was proposed. The study results suggest that the Schiff base copper complex, as a potent catalyzer, may find its applications in catalytic degradation area.

A highly sensitive and visible-light-driven photoelectrochemical (PEC) sensor has been constructed for the quantitative assay of organophosphorus pesticides like chlorpyrifos (Chlo) using hollow Co9S8@CdS heterostructures. The Co9S8@CdS heterostructures were created by growing CdS onto Co9S8 surface via one-step oil-bath route, of which Co9S8 was fabricated with hollow tubular structures through the Co(CO3)0.35Cl0.2(OH)1.1-templated solvothermal method. It was discovered that the so-obtained Co9S8@CdS with direct Z-scheme heterojunctions could exhibit larger photocurrents than the Co9S8 or CdS because of the greatly enhanced separation efficiency of photo-generated carriers. What’s more, the photocurrent signal of Co9S8@CdS-based PEC sensor could be selectively inhibited with the addition of Chlo through the specific chelation between the N and S atoms of Chlo with C N and P S groups and Co sites of Co9S8@CdS so as to suppress the carriers transferring. The developed PEC sensor could exhibit a linear response for Chlo ranging from 0.050 to 1000 ppb, with the detection limit value down to 0.015 ppb, which was far below than those of currently reported PEC sensors. Besides, the proposed routes may provide guidelines for designing various direct Z-scheme heterojunction-based PEC analysis platforms for determining environmental pollutants like Chlo.

Trichloropyridinol (TCP); 3, 5, 6-trichloro-2-pyridinol is the primary metabolites of the organophosphorus pesticide chlorpyrifos. It is more highly persistent than parent compounds in the environment and might represent serious risks to human health. In this study, we investigated the toxicological effects and mechanism of TCP on HepG2 cells. The results revealed that TCP induced DNA damage and apoptosis on HepG2 cells. Besides, up-regulating the expression level of Bax /Bcl-2, a reduction in mitochondrial membrane potential, caspase-9/-3 activation and the release of cytochrome-c are contributed to the toxicological effects of TCP on HepG2 cells. These data indicated that the cytotoxic effects of TCP might be associated with the activity of mitochondrial apoptotic pathways. In conclusion, the results demonstrated that TCP poses a potential threat to human health by inducing toxicological effects in the liver.

Based on the unique properties of carbon dots (CDs), a number of detection methods with high performances have been built through various strategies for different pesticides and veterinary drugs, including organophosphorus pesticides, tetracyclines, quinolones and others. The performances of these detection methods are comparable or even better than conventional approaches as detection limits of some methods can reach pg/mL level. However, these methods have not been systematically reviewed. This article aims to provide a comprehensively review on the main response mechanisms of CDs to such analytes, selectivity improvement approaches and their wide applications in the detections of pesticides and veterinary drugs in water, plant and animal foods, etc. It is our hope that this review will promote the advance of CDs applied in the detections of pesticides and veterinary drugs, and open perspectives toward the construction of new detection methods based on CDs with high sensitivity, selectivity and accuracy.

A novel pH-responsive fluorescence probe, (4-morpholinomythyl) boronic acid (4-MPBA), was synthesized and employed for the detection of organophosphorus pesticides (OPs) in fruit juices. 4-MPBA was sensitive to pH changes in the range of 3.0–5.8 with R2 of 0.9914, which was based on the inhibitory reaction between OPs and acetylcholinesterase (AChE). The linear range spanned over the range of 0.80–32 μg·L−1 with limits of detection of 0.16–0.24 μg·L−1. This fluorescence assay was utilized for detecting trace-level OPs with satisfactory recoveries (95.73–104.50%) and RSDs of

The development of highly active biomimetic catalysts with peroxidase (POD)-like activity and realization of vivid mimicking of the active sites of natural enzymes still remains a huge challenge. Herein, atomically dispersed Fe atoms on hierarchically S/N co-doped porous carbon (FeSNC) featured with the unsymmetrically coordinated Fe-N3S1 as active sites were synthesized by a template-assisted method. The resultant FeSNC exhibits higher POD-like activity than FeNC featured with Fe-N4 sites. Owing to the S doping-induced geometric/electronic effects, Fe-N3S1 not only lengthens the O O bonding distances of adsorbed H2O2 but also accelerates the electronic transfer between Fe and O, decreasing the energy barrier of the formation of the active intermediate and thus achieving the boosted POD-like activity. Finally, the sensitive detection of organophosphorus pesticides was performed by adjusting the POD-like activity of FeSNC, exhibiting satisfactory sensitivity and selectivity. This work provides great promise for the accurate design of single-atom catalysts for vivid mimicking the function of natural enzymes.

A multicolor enzyme-linked immunosorbent sensor was constructed to detect organophosphates pesticides (OPs) on base of TMB2+-mediated AuNRs etching. As the etching progresses, a rainbow-like color responses was generated. The naked eye limit of detection (LOD) of the sensing system is 0.25 ng mL−1. In particular, the longitudinal localized surface plasmon resonances (LSPR) peak shift of AuNRs is linearly correlated with the logarithm of OPs concentration in range of 104 to 5 × 106 pg mL−1 for parathion-methyl and fenitrothion, 5 × 104 to 107 pg mL−1 for fenthion, respectively. Compared with reported methods, this sensor displayed satisfactory linear ranges and detection limits. Average recoveries of this method ranged from 73.28% to 98.08% and relative standard deviations (RSDs) were below 8.0% as for food samples analysis without complicated pretreatments. Remarkably, the developed multicolor enzyme-linked immunosorbent sensor is capable of providing accurate and reliable assay for OPs in complex food samples.

Chlorpyrifos as one of organophosphorus pesticides, is easily absorbed by human skin and dangerously causing inhibition of acetylcholinesterase that is essentially required for transporting nerve impulse. Therefore, the current approach focused on the adsorptive removal of Chlorpyrifos using superior adsorptive membrane composed of Al-metal organic framework@cellulose acetate (MIL-53-NH2@CA). The membrane was uniquely synthesized in two sequential steps; firstly, preparation of porous CA membrane and consequently, incorporation of MIL-53-NH2 within the synthesized porous CA membrane. Procedure was performed to impregnate various ratios of MIL-53-NH2 (20–60%) within the porous CA membrane. Micro-particles MIL-53-NH2 was successively immobilized within the membrane, while, the pore diameter was ranged in 124.5–485.6 nm. Adsorptive removal of chlorpyrifos through the prepared membrane was corresponded to Langmuir isotherm and pseudo-second ordered reaction. The maximum adsorptive capacity was observably increased from 160.36 mg/g for CA to 207.62–356.34 mg/g for MIL-53-NH2@CA. Impregnation of 60% MIL-53-NH2 resulted in fastening of the adsorptive removal rate of chlorpyrifos by factor of 2.2. The employed membrane exhibited very good recoverability and the adsorptive compatibility was diminished by 27.9% after five reuses. The prepared MIL-53-NH2@CA membrane can be promisingly applicable in the superior removal of pesticides and in various environmental applications.

Several studies have suggested that exposure to organophosphorus (OP) pesticides is detrimental for health, and in particular for children where moderate doses may have a negative impact on the neurodevelopment. This study surveys levels of the 6 non-specific urinary metabolites (dialkyl phosphates (DAPs)) of OP pesticides in Norwegian mothers (n = 48) and their children (n = 54), and examines the diurnal variation in concentrations as well as associations with consumption of specific food products. The highest median concentration measured in urine was found for dimethyl thiophosphate (5.3 and 5.5 ng/mL SG ; specific gravity corrected) for both children and mothers, respectively, followed by diethyl phosphate (3.8 and 5.3 ng/mL SG , respectively). The intra-class correlation coefficients of DAPs among mothers were moderate (0.49–0.68), and consumption of fruit explained between 8% and 55% of the variations in the mothers' and their children's urinary DAP concentrations.

In this study, we demonstrated an assay with turn-on fluorescence for monitoring cerebrospinal acetylcholinesterase (AChE) fluctuation as a biomarker for organophosphorus pesticides (OPs) poisoning and management based on single layer MnO2 nanosheets with graphene quantum dots (GQDs) as signal readout. Initially, the fluorescence of GQDs was quenched by MnO2 nanosheets mainly due to the inner filter effect (IFE). However, with the presence of reductive thiocholine (TCh), the enzymatic product, hydrolyzed from acetylthiocholine (ATCh) by AChE, the redox reaction between MnO2 and TCh occurred, leading to the destruction of the MnO2 nanosheets, and thereby IFE was diminished gradually. As a consequence, the turn-on fluorescence of GQDs with the changes in the spectrum of the dispersion constituted a new mechanism for sensing of cerebrospinal AChE. With the method developed here, we could monitor cerebrospinal AChE fluctuation of rats exposed to OPs before and after therapy, and could thereby open up the pathway to a new sensing platform for better understanding the mechanism of brain dysfunctions associate with OPs poisoning.

Assays for organophosphorus pesticides (OPs) with high sensitivity as well as on-site screening have been urgently required to protect ecosystem and prevent disease. Herein, a novel fluorimetric sensing platform was constructed for quantitative detection of OPs via tyrosinase (TYR) enzyme-controlled quenching of gold nanoclusters (AuNCs). One-step green synthetic approach was developed for the synthesis of AuNCs by using chicken egg white (CEW) as template and stabilizer. Initially, TYR can catalyze the oxidation of dopamine to dopaminechrome, which can efficiently quench the fluorescence intensity of AuNCs at 630 nm based on dynamic quenching process. However, with the presence of OPs, the activity of TYR was inhibited, resulting in the fluorescence recovery of AuNCs. This proposed fluorescence platform was demonstrated to enable rapid detection for OPs (paraoxon as model) and to provide excellent sensitivity with a detection limit of 0.1 ng mL −1 . Significantly, the fluorescence probe was used to prepare paper-based test strips for visual detection of OPs, which validated the excellent potential for real-time and on-site application.

Background: Current exposure assessment research does not sufficiently address multi-pollutant exposure and their correlations in human media. Understanding the extent of chemical exposure in reproductive-aged women is of particular concern due to the potential for in utero exposure and fetal susceptibility.Objectives: The objectives of this study were to characterize concentrations of chemical biomarkers during preconception and examine correlations between and within chemical classes. Methods: We examined concentrations of 135 biomarkers from 16 chemical classes in blood and urine from 73 women aged 18-40 enrolled in Snart Foraeldre/Milieu, a prospective cohort study of pregnancy planners in Denmark (2011-2014). We compared biomarker concentrations with United States similarly-aged, nonpregnant women who participated in the National Health and Nutrition Environmental Survey (NHANES) and with other international biomonitoring studies. We performed principal component analysis to examine biomarker correlations.Results: The mean number of biomarkers detected in the population was 92 (range: 60-108). The most commonly detected chemical classes were phthalates, metals, phytoestrogens and polycyclic aromatic hydrocarbons. Except blood mercury, urinary barium and enterolactone, geometric means were higher in women from NHANES. Chemical classes measured in urine generally did not load on a single component, suggesting high between-class correlation among urinary biomarkers, while there is high within-class correlation for biomarkers measured in serum and blood.Conclusions: We identified ubiquitous exposure to multiple chemical classes in reproductive-aged Danish women, supporting the need for more research on chemical mixtures during preconception and early pregnancy. Inter- and intra-class correlation between measured biomarkers may reflect common exposure sources, specific lifestyle factors or shared metabolism pathways.

The aim of this study was to investigate the applicability of the adsorption process for the removal of organophosphorus pesticide malathion 57% from water by using multi-walled carbon nanotubes (MWCNTs). The impact of various experimental conditions such as pH, quantity of adsorbent, concentration of pesticides, contact time and temperature was studied and optimized for the maximum removal of malathion. Unlike conventional optimization, a limited number of experiments (26 steps) were performed in a cost-effective manner for different independent variables such as MWCNTs concentration (0.1–0.5 g/L), the malathion (57%) concentration (6 mg/L and 10 mg/L), contact time (2–30 min) and pH (neutral range). Based on the experimental data obtained in a lab-scale batch study, a three-factor response surface modeling (RSM) approach was implemented in order to optimize the conditions for maximum removal of malathion, and compare experimental results with standardized malathion samples. The optimized conditions to achieve the maximum removal of malathion (100%) were determined to be a malathion concentration of 6 mg/L, an initial MWCNTs concentration of 0.5 g/L, and a contact time of 30 min. Findings of this study clearly indicated that 100% of the malathion could be cost-effectively removed by MWCNTs in conditions predicted by the proposed optimization methodology.

Biosensors using acetylcholinesterase (AChE) as the recognition element detect both toxicity (AChE inhibition activity) and concentration of organophosphorus pesticides (OPs). However, real application of these biosensors remains a challenge due to their low selectivity and low resistance to sample matrix, interferences and hash analytical conditions. In this study, a novel dual-recognized strategy was established by using molecularly imprinted polymer (MIP) and AChE selective to different moieties of acephate (AP) as affinity molecules simultaneously. Using AP as the model OP, MIP highly selective to certain moieties but not phosphorus of AP was prepared on the surface of microplate by self-polymerization of dopamine. The MIP enriched AP from samples selectively. Then AChE selective to phosphorus of AP quantified the levels of AP captured by MIP. AP captured by MIP still inhibited the activity of AChE because the affinity of AP to AChE was higher than to MIP. By incorporating selective sample pretreatment with AChE inhibition assay in one sensor, the biosensor identified AP from other OPs, carbamates pesticides and interferences commonly found in food and environmental samples. When vegetables with high matrix effect on AChE inhibition assay were analyzed, selective sample pretreatment ensured the biosensor to detect AP more accurately and selectively than classical AChE inhibition assay. The results of the biosensor had no statistical difference compared with those of HPLC-MS/MS. The dual-recognized strategy may provide a new solution to detect target enzyme inhibitors in complicated samples using enzyme-based biosensors selectively and accurately.

In order to better remove the interfering substances in the vegetables, a type of tetraethylenepentamine modified multi-wall carbon nanotubes has been prepared. As-prepared materials contain amino-groups and organic chains, and magnetism is endowed by using physical blending method. Taking the magnetic tetraethylenepentamine modified multi-walled carbon nanotubes as matrix clean-up agents and combining with GC-MS, a modified QuEChERS method was established for the pesticide residues analysis in cucumber. The recoveries of 10 pesticide targets were 73.5%–114.2%, and the RSDs were between 4.9% and 18.6%, which could meet the requirements of food safety testing. Compared with the traditional clean-up materials, the prepared materials exhibited better clean-up performance while simplifying the pretreatment process. Given the excellent clean-up performance of the proposed materials, it was expected to be used in the clean-up process of other samples with complex contents.

Organophosphorus (OPs) pesticides have been widely used for crop protection in conventional agricultural fields. The OPs residues in the soil, food, and surface- and ground-water can reach humans and irreversibly inhibit the acetylcholinesterase (AChE) via phosphorylation causing brain dysfunction and cholinergic crisis, which finally leads to death. Even the low concentration of OPs induces lymphoma in the human system. Traditional analytical methods for sensing OPs possess significant limitations such as prolonged responses, expensive, and required complicated detection procedures. Recently, the development of AChE inhibition based biosensors provided a simple platform for the quick and feasible detection of the OPs and its metabolites in the actual (food, agro, and water) samples. In the current review, we aim to present the overview of the recent advancements and novel findings in various AChE inhibition based sensing strategies especially, optical, electrochemical, lab-on-paper sensors, microfluidic, and other devices for the rapid detection of OPs pesticides within the period of Jan. 2018 to Aug. 2020. Additionally, the significant achievements of nanotechnology in AChE inhibition based sensing strategies, recent patents, and commercially available OPs detection kits have also been reviewed. Further, the working mechanisms, sensing parameters, analytical performances, advantages, and drawbacks of different AChE based OPs sensors have been compared and discussed. Finally, the present challenges, research gaps, and future outlooks in AChE inhibition based OPs detection are highlighted. This profound investigation on AChE based OPs detection techniques will offer knowledge for further improvements towards the commercial development of a novel biosensor for the detection of a wide range of OPs compounds.

In order to meet the requirements of pesticide residues' detection in complex matrix samples, the magnetic fluorinated multi-wall carbon nanotubes (M-F-MWCNTs) were prepared and applied as new QuEChERS clean-up materials. Combined with GC-MS, an improved QuEChERS method was successfully developed for the detection of organophosphorus pesticide residues. The results showed that the M-F-MWCNTs could effectively remove the interfering substances in Lycium ruthenicum Murr. (L. ruthenicum) samples. The recoveries of 10 tested targets were 74.9% to 113.5% with the relative standard deviations (RSDs) of 3.9-14.7%. The experiment results pointed out that the M-F-MWCNTs were qualified as QuEChERS clean-up materials and expected to be applied to other complex matrix samples and pesticide targets.

Agricultural activity demands the use of pesticides for plague control and extermination. In that matter, diazinon is one of the most widely used organophosphorus pesticides (OPs). Despite its benefits, the use of OPs in agricultural activities can also have negative effects since the excessive use of these substances can represent a major contamination problem for water bodies and organisms that inhabit them. The aim of this paper was to evaluate oxidative damage in lipids and proteins of Nile tilapia (Oreochromis niloticus) exposed acutely to diazinon (0.97, 1.95 and 3.95 ppm) for 12 or 24 h. The evaluation of oxidative damage was determined by quantifying lipid hydroperoxides (Fox method) and oxidized proteins (DNPH method). The data from this study suggest that diazinon induces a concentration-dependent oxidative damage in proteins, but not lipids, of the liver and gills of Nile tilapia. Furthermore, the treatment leads to a decrease in the concentration of total proteins, which can have serious consequences in cell physiology and fish development.

The widespread use of organophosphate pesticides (OPPs) in agriculture leads to residue accumulation in the environment which is dangerous to human health and disrupts the ecological balance. In this work, one nanocomposite immobilized zirconium (Zr, IV) was prepared and used as the affinity probes to quickly and selectively extract organophosphorus pesticides (OPPs) from water samples. The Fe3O4-ethylenediamine tetraacetic acid (EDTA)@Zr(IV) nanocomposites (NPs) were prepared by simply mixing Zr(IV) ions with Fe3O4-EDTA NPs synthesized by one-pot chemical co-precipitation method. The immobilized Zr(IV) ions were further utilized to capture OPPs based on their high affinity for the phosphate moiety in OPPs. Coupled with GC–MS, four OPPs were used as models to demonstrate the feasibility of this approach. Under the optimum conditions, the limits of detection for target OPPs were in the range of 0.10–10.30 ng mL−1 with relative standard deviations (RSDs) of 0.61–4.40% (n = 3), respectively. The linear ranges were over three orders of magnitudes (correlation coefficients, R2 > 0.9995). The Fe3O4-EDTA@Zr(IV) NPs were successfully applied to extract OPPs samples with recoveries of 86.95–112.60% and RSDs of 1.20–10.42% (n = 3) from two spiked real water. By the proposed method, the matrix interference could be effectively eliminated. We hope our finding can provide a promising alternative for the fast extraction of OPPs from complex real samples.

A simple, rapid, solventless and cost-effective dynamic microwave-assisted extraction (DMAE) combined with continuous-flow microextraction (CFME) system was firstly assembled and validated for extraction of eight organophosphorus pesticides in vegetables. The method combines the advantages of DMAE and CFME, and extends the application of the single drop microextraction to complex solid samples. The extraction, separation, and enrichment were performed in a single step, which could greatly simplify the operation and reduce the whole pretreatment time. In the developed method, analytes were first extracted from the vegetables using 3% NaCl solution as extraction solvent, then concentrated into microextraction solvent. After extraction, the microextraction solvent containing the enriched analyte was directly analyzed by GC-MS without any filtration or clean-up process. Several parameters affecting the extraction efficiency were investigated and optimized. Real vegetable samples were analyzed, satisfactory recoveries were obtained in the range of 80.7-106.7%, and relative standard deviations were lower than 8.7%.