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Cucumber (Cucumis sativus L.) is the world's most widely consumed salad vegetable, and it is frequently treated with pesticides to prevent pest and disease outbreaks. Pesticide residues in food commodities impede trade and pose a major health risk. Prior to residue estimation, the QuEChERS approach was validated utilising criteria such as limit of detection, limit of quantitation, linearity, accuracy, and precision. The residues of carbendazim, cypermethrin, ethion, profenofos, quinalphos, and triazophos were examined using a Gas Chromatograph equipped with an Electron Capture Detector or a Flame Photometric Detector and a high-performance liquid chromatography coupled to a photo diode array. The initial deposits of carbendazim, cypermethrin, ethion, profenofos, quinalphos, and triazophos at the prescribed dose were 1.235, 0.407, 0.817, 0.960, 0.628, and 0.985 mg/kg, respectively, with a pre-harvest interval of 5.58-11.30 days. According to the consumer risk evaluation data, the Hazard Quotient is less than one, and the Theoretical Maximum Dietary Intake is less than the Maximum Permissible Intake and Maximum Residue Limit, both of which are considered safe for human consumption at the authorised dose., (© 2024. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

For addressing the challenges of strong affinity SERS substrate to organophosphorus pesticides (OPs), herein, a rapid water-assisted layer-by-layer heteronuclear growth method was investigated to grow uniform UiO-66 shell with controllable thickness outside the magnetic core and provide abundant defect sites for OPs adsorption. By further assembling the tailored Au@Ag, a highly sensitive SERS substrate Fe 3 O 4 -COOH@UiO-66/Au@Ag (FCUAA) was synthesized with a SERS enhancement factor of 2.11 × 10 7 . The substrate's suitability for the actual vegetable samples (cowpeas and peppers) was confirmed under both destructive and non-destructive detection conditions, showing a strong SERS response to fenthion and triazophos, with limits of detection of 1.21 × 10 -5 and 2.96 × 10 -3 mg/kg in the vegetables under destructive conditions, and 0.13 and 1.39 ng/cm 2 for non-destructive detection, respectively. The FCUAA substrate had high SERS performance, effective adsorption capability for OPs, and demonstrated good applicability, thus exhibiting great potential for rapid detection of trace OPs residues in the food industry., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)

Organophosphate pesticides (OPs) are often used as insecticides and acaricides in agriculture, thus improving yields. OP residues may pose a serious threat, duetoinhibitionof the enzymeacetylcholinesterase(AChE). Therefore, a competitive bio-barcode immunoassay was designed for simultaneous quantification of organophosphate pesticide residues using AuNP signal amplification technology and Au@Pt catalysis. The AuNP probes were labelled with antibodies and corresponding bio-barcodes (ssDNAs), MNP probes coated with ovalbumin pesticide haptens and Au@Pt probes functionalized with the complementary ssDNAs were then prepared. Subsequently, pesticides competed with MNP probes to bind the AuNP probes. The recoveries of the developed assay were ranged from 71.26 to 117.47% with RSDs from 2.52 to 14.52%. The LODs were 9.88, 3.91, and 1.47 ng·kg -1 , for parathion, triazophos, and chlorpyrifos, respectively. The assay was closely correlated with the data obtained from LC-MS/MS. Therefore, the developed method has the potential to be used as an alternative approach for detection of multiple pesticides., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Herein, a novel visual method for detecting triazophos based on competitive bio-barcode immunoassay was described. The competitive immunoassay was established by gold nanoparticles (AuNPs), magnetic microparticle (MMPs) and triazophos, combined with biochip hybridization system to detect the residual of triazophos in water and apple. Because AuNPs carried many bio-barcodes, which hybridized with labeled DNA on the biochip, catalyzed signal amplification using silver staining was detected by grayscale values as well as the naked eye. Notably, the grayscale values decreases with increasing the concentrations of triazophos, and the color change weakened gradually. The detection range was in between 0.05 and 10 ng/mL and the minimum detection limit was set at 0.04 ng/mL. Percent recovery calculated from spiked water and apple samples ranged between 55.4 and 107.8% with relative standard deviations (RSDs) of 12.4-24.9%. It has therefore been shown that this protocol provides a new insight for rapid detection of small molecule pesticides in various matrices., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

In this work, a colorimetric sensor array has been designed for the identification and discrimination of thiometon (TM) and phosalone (PS) as organophosphate pesticides and prothioconazole (PC) as a triazole pesticide. For this purpose, two different plasmonic nanoparticles including unmodified gold nanoparticles (AuNPs) and unmodified silver nanoparticles (AgNPs) were used as sensing elements. The principle of the proposed strategy relied on the aggregation AuNPs and AgNPs through the cross-reactive interaction between the target pesticides and plasmonic nanoparticles. Therefore, these aggregation-induced UV-Vis spectra changes were utilized to discriminate the target pesticides with the help of linear discriminant analysis (LDA). Besides, we have employed the bar plots and the heat maps as visual non-statistical methods to differentiate the pesticides in a wide range of concentrations (i.e., 20-5000 ng mL -1 ). Multivariate calibration plots from partial least squares (PLS)- regression indicated that the responses linearly depend on the pesticide concentrations in the range of 100-1000 ng mL -1 with the limit of detections (LOD) of 66.8, 68.3, and 41.4 ng mL -1 , for TM, PS, and PC, respectively. Finally, the potential applicability of the proposed sensor array has been evaluated for the detection and identification of the pesticides in the mixtures, water samples, and cucumber fruit., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Triazophos (TAP), methamidophos (MAP) and carbofuran (CF) pesticides are highly toxic, soluble and absorbable. Efficient co-degradation of multi-pesticides is rare reported. The objectives of this study were to investigate TAP, MAP and CF co-degradative ability of Enterobacter sp. Z1 and study the degradation mechanisms. Strain Z1 was shown to efficiently co-degrade TAP, MAP and CF when they were used as primary carbon sources. The degradation occurred over a wide range of temperatures, pH values and pesticide concentrations and followed first-order kinetics. Under the optimum conditions (37 °C, pH 7 and 100 mg/L of each pesticide), the degradation efficiencies were 100%, 100%, and 95.3% for TAP, MAP and CF, respectively. In addition, strain Z1 could simultaneously degrade TAP, MAP, CF and total nitrogen in wastewater in a batch bioreactor, with high removal efficiencies of 98.3%, 100%, 98.7% and 100%, respectively. Genomics, proteomics, qRT-PCR and gene overexpression analyses revealed that the degradation mechanisms involved the activities of multiple proteins, among which, organophosphorus hydrolase (Oph) and 3-hydroxyacyl-CoA dehydrogenase (PaaC) are primarily responsible for TAP and MAP degradation, while carbofuran hydrolase (Mcd) and amidohydrolase (RamA) primarily degrade CF. Among these enzymes, PaaC and RamA are newly identified pesticide-degrading enzymes. Toxicity assays of strain Z1 using reporter recombinase gene (recA) and zebrafish showed that there was no accumulation of toxic metabolites during the degradation process. Biosafety test using zebrafish showed that the strain was nontoxic toward zebrafish. Strain Z1 provides a good purification effect for pesticides-containing wastewater and novel microbial pesticide-degrading mechanisms were discovered., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Herein, we developed a multi-analyte fluorescence immunoassay for detection of three organophosphate pesticides (triazophos, parathion, and chlorpyrifos) in various agro-products (rice, wheat, cucumber, cabbage, and apple) using fluorescently labeled oligonucleotide and gold nanoparticle (AuNP) signal amplification technology. The AuNP probes for the three analytes were constructed by simultaneously modifying the corresponding antibodies and fluorescently labeled oligonucleotides on the probe surface. Three fluorophores (6-FAM, Cy3, and Texas red) with high fluorescence intensity and little overlap of excitation/emission wavelengths were selected. The method showed satisfactory linearity for triazophos, parathion, and chlorpyrifos in the ranges of 0.01-20, 0.05-50, and 0.5-1000 μg/L, respectively. For the 3 analytes, the limits of detection (LODs) were 0.007, 0.009, and 0.087 μg/L, respectively. The average recoveries were 77.7-113.6%, with relative standard deviations (RSDs) of 7.1-17.1% in various food matrices. The proposed method offers great potential in food safety surveillance, and could be used as well as a reference for multi-residue analysis of other small-molecule contaminants., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

A highly reproducible surface-enhanced Raman scattering (SERS) unsupported liquid-state platform (ULP) was developed for accurate quantitative determination of triazophos. Herein, citrate-reduced Ag NPs suspension was concentrated and placed in a stainless steel perforated template to form the SERS ULP. The relative standard deviation of the SERS measurements was less than 5% (n ≥ 10), and the R 2 of the calibration curve was 0.994. The developed SERS ULP was applied for determination of triazophos in spiked agricultural products (rice, cabbage, and apple). Experiment results showed that the coefficient of variation ranged from 5.3 to 6.2% for intra-day and from 5.5 to 6.3% for inter-day (n = 3), which proved excellent SERS reproducibility. Moreover, the results were in good agreement with those from HPLC analysis. As a liquid-state SERS substrate, the highly reproducible ULP can perform precision quantitative analysis without surface modification of NPs, which is a significant improvement. This method provides a new perspective for quantitative SERS analysis of pesticide residues. Graphical abstract.

For the first time it is demonstrated that sulfhydryl compounds can suppress longitudinal etching of gold nanorods via consuming oxidizers, which provides a new signaling mechanism for colorimetric sensing. As a proof of concept, a colorimetric assay is developed for detecting organophosphorus pesticides, which are most widely used in modern agriculture to improve food production but with high toxicity to animals and the ecological environment. Triazophos was selected as a model organophosphorus pesticide. In the absence of triazophos, the active acetylcholinesterase can catalyze the conversion of acetylthiocholine iodide to thiocholine whose thiol group can suppress the I 2 -induced etching of gold nanorods. When triazophos is present, the activity of AchE is inhibited, and I 2 -induced etching of gold nanorods results in triazophos concentration-dependent color change from brown to blue, pink, and red. The aspect ratio of gold nanorods reduced with gradually blue-shifted longitudinal absorption. There was a linear detection range from 0 to 117 nM (R 2  = 0.9908), the detection limit was 4.69 nM, and a good application potential was demonstrated by the assay of real water samples. This method will not only contribute to public monitoring of organophosphorus pesticides but also has verified a new signaling mechanism which will open up a new path to develop colorimetric detection methods. It has been first found that sulfhydryl compounds can suppress longitudinal etching of gold nanorods (AuNRs) via consuming oxidizers, which provides a new signaling mechanism for colorimetric sensing. As a proof of concept, a colorimetric assay is developed for sensitively detecting organophosphorus pesticides (OPs). It will not only contribute to public monitoring of OPs but also has verified a new signaling mechanism which will open up a new path to develop multicolor colorimetric methods.

An accurate and sensitive dispersive liquid-liquid microextraction method based on binary solvents was used to enrich prothiofos, oxadiargyl, and gamma-cyhalothrin for quantification by GC-MS. The combination of two extraction solvents (binary mixture) resulted in higher extraction efficiencies compared to the single solvent extraction systems. Parameters of the binary extraction method where optimized to enhance the extraction output of the analytes. The limits of detection calculated for the analytes ranged between 0.59 and 1.6 ng/mL. Linear calibration plots of the analytes covered wide concentration ranges with R 2 values greater than 0.9996 and percent relative standard deviation lower than 10%. Spiked recovery experiments were performed well and wastewater at two different concentrations and satisfactory results (89-104%) were obtained. The binary solvent microextraction method was combined with QuEChERS to quantify the analytes in pineapple matrix, using matrix matching method to enhance the accuracy of the method to almost 100%.

Background: A new type of deep eutectic solvent based on three components using phosphate salts has been synthesized, characterized, and applied in the extraction of eight organothiophosphate pesticides from honey samples. In this study, the deep eutectic solvent was prepared from phosphocholine choline chloride as a hydrogen bond acceptor and dichloroacetic acid and decanoic acid as hydrogen bond donors. The method consisted of two steps in which initially the analytes were extracted from the samples into a water-miscible organic solvent. In the second step, the extracted phase was mixed with the prepared deep eutectic solvent and the mixture was used in the following dispersive liquid-liquid microextraction method., Results: The method was validated under optimal conditions, and it was found that it has low limits of detection (0.05-0.10 ng g -1 ) and quantification (0.19-0.36 ng g -1 ), good linearity (r 2  ≥ 0.994), broad linearity (0.36-1000 ng g -1 ), and satisfactory repeatability (relative standard deviation ≤10% for intra- (n = 6) and inter-day (n = 4) precisions at a concentration of 2 ng g -1 of each analyte)., Conclusion: The proposed method was applied in different honey samples, and malathion was found at a concentration of 29 ng g -1 in one sample. © 2019 Society of Chemical Industry., (© 2019 Society of Chemical Industry.)

An ultrasensitive bio-barcode competitive immunoassay method based on droplet digital polymerase chain reaction (ddPCR) was developed for the determination of triazophos. Gold nanoparticles (AuNPs) were coated with monoclonal antibodies (mAbs) and complementary double-stranded DNA (dsDNA), which included bio-barcode DNA and thiol-capped DNA. Magnetic nanoparticle (MNP) probes were constructed by modifying the MNPs with ovalbumin-hapten conjugates (OVA-hapten). The target pesticide and OVA-hapten on the surface of the MNP probes competed with the AuNP probes simultaneously, and then the bio-barcode DNA was released for quantification by ddPCR. The concentration of released DNA was inversely proportional to the concentration of pesticide to be tested. Under the optimum conditions, the competitive immunoassay exhibited a wide linear range of 0.01-20 ng/mL and a low detection limit of 0.002 ng/mL. Spike recovery tests were carried out using apple, rice, cabbage, and cucumber samples to verify the feasibility of the method. The recovery and relative standard deviations (RSDs) of the technique ranged from 76.9 to 94.4% and from 10.8 to 19.9%, respectively. To further validate the results, a linear correlation analysis was performed between the proposed method and liquid chromatography-tandem mass spectrometry (LC-MS/MS). Consequently, the bio-barcode immunoassay based on nanoparticles and ddPCR, an ultrasensitive method, showed great potential for the determination of target pesticides in real samples.

A new and facile method for selective measurement of profenofos (PFF) using a simple flow-injection system with a molecularly-imprinted-polymer-coated carbon nanotube (3D-CNTs@MIP) amperometric sensor is proposed. The 3D-CNTs@MIP was synthesized by successively coating the surface of carboxylated CNTs with SiO 2 and vinyl end groups, then terminating with molecularly imprinted polymer (MIP) shells. MIP was grafted to the CNT cores using methacrylic acid (MAA) monomer, ethylene glycol dimethacrylate (EGDMA) as cross linker, and 2,2'-azobisisobutyronitrile (AIBN) as initiator. We constructed the PFF sensor by coating the surface of a glassy carbon electrode (GCE) with 3D-CNTs@MIP and removed the imprinting template by solvent extraction. Morphological and structural characterization reveal that blending of the MIP on the CNT surface significantly increases the selective surface area, leading to greater numbers of imprinting sites for improved sensitivity and electron transfer. The 3D-CNTs@MIP sensor exhibits a fast response with good recognition when applied to PFF detection by cyclic voltammetry and amperometry. The PFF oxidation current signal appears at +0.7 V vs Ag/AgCl using 0.1 M phosphate buffer (pH 7.0) as the carrier solution. The designed 3D-imprinted sensor provides a linear response over the range 0.01-200 μM (r 2  = 0.995) with a low detection limit of 0.002 μM (3σ). The sensor was successfully applied to detection of PFF in vegetable samples., (Copyright © 2019 Elsevier B.V. All rights reserved.)

In this work, we report a simple and rapid surface-enhanced Raman scattering (SERS) method for the screening of pesticide residues on fruit peels using a portable Raman spectrometer. Adhesive tapes were used as the sampling media; the effectiveness of different tape brands was examined. Collection efficiencies were found to be 60.2 ± 7.6%, 54.3 ± 5.0%, and 52.3 ± 9.0% on glass, aluminum foil, and fruit peels, respectively. SERS was achieved by applying silver nanoparticles (Ag NPs) to the surface of the tape after analyte collection. Preparation of the Ag NPs was optimized for pesticide detection. The limit of detection of triazophos on apple peels was 25 ng/cm 2 with the portable Raman spectrometer. Considering the least favorable conditions, the calculated detection limit was 0.0225 mg/kg, which is an order of magnitude less than the maximum residue limit (MRL, 0.2 mg/kg) in China. The method is sufficiently sensitive for use in field analysis., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Presented in this study is a simple but efficient switchable polarity solvent microextraction strategy for etrimfos preconcentration from water and food samples for quantification by gas chromatography mass spectrometry. Repeatability of the extraction process and instrumental measurements were enhanced by using deuterated bisphenol A as internal standard. Significant parameters of the extraction method were fitted into an experimental design model to study the effects of parameters on extraction output, as well as mutual effects of combined parameters. The design model was formed with 51 experimented data obtained from the combination of sodium hydroxide volume, switchable solvent volume, and vortex period at three levels. The method was validated by applying optimum conditions attained from the model predictor. The detection limit was found to be 1.3 ng/mL and it corresponded to an enhancement factor of about 54 folds when compared to direct GC-MS measurement. Etrimfos was not detected in the water and food samples tested but the results (92-107%) obtained from spiked recovery experiments established that etrimfos when present in the selected matrices can be accurately and precisely quantified.

The biomimetic enzyme-linked immunosorbent assay (BELISA) is widely used for detection of small-molecule compounds as a result of low cost and reagent stability of molecularly imprinted polymers (MIPs). However, enzyme labels used in BELISA still suffer some drawbacks, such as high production cost and limited stability. To overcome the drawbacks, a biomimetic nanozyme-linked immunosorbent assay (BNLISA) based on MIPs and nanozyme labels was first proposed. For nanozyme labels, platinum nanoparticles (PtNPs) acted as peroxidase by catalyzing the oxidation of colorless 3,3',5,5'-tetramethylbenzidine (TMB) into an ideal surface-enhanced Raman scattering (SERS) marker. Blue TMB 2+ and bovine serum albumin (BSA)-hapten showed superior selectivity when competing with targets for binding sites on MIPs, named the Pt@BSA-hapten probe. The BNLISA method was employed to detect triazophos with a limit of detection of 1 ng mL -1 via colorimetric and SERS methods. Replacing traditional enzymes with nanozymes for combination with MIPs may bring about a new prospect for other compound analyses.

Sixty-four table grape samples from different regions of Tunisia were collected during three consecutive years (2015-2017). The presence of 96 pesticides, including dithiocarbamates, was assessed. Pesticides identification and quantification were performed by liquid or gas chromatography, coupled to tandem mass spectrometry. All samples contained multiple residues (4 to 24 residues), with an average of 11.6 residues per sample. Individual concentrations of pesticides in grapes ranged from 0.01 to 5.86 mg kg -1 . For at least one chemical compound, exceedances of the European Maximum Residue Limits were found in 94% of the samples. To assess the potential risk of pesticides through consumption of grapes, the acute exposure was estimated by the determination of predicted short term intake which is expressed as a percentage of Acute Reference Dose (ARfD), for non-compliances of pesticides. The exceedance of ARfD was associated with carbofuran, carbendazim, chlorpyrifos, deltamethrin, dimethoate and omethoate. Consequently, these pesticides could present a risk for consumer's health.

Background: The increasing and extensive use of pesticides worldwide has resulted in a significant loss of non-target populations particularly humans by direct or indirect exposures. Also, various methods have been used for the estimation of pesticide residues in fruits and vegetables from recent past which are either tedious, time consuming or expensive. Therefore, the present study was performed to determine the pesticide residues from apple by simple and novel validated gas chromatography., Results: A novel, accurate, ecofriendly and cost-effective gas chromatography method was developed for simultaneous quantification of eight pesticides, namely chlorpyrifos-methyl (1), chlorpyrifos (2), quinolphos (3), profenofos (4), myclobutnil (5), ethion (6), fenpropathrin (7) and cypermethrin (8). The developed method was validated as per the SANTE guidelines. All calibration curves showed a good linear relationship (r > 0.99) within the test range. Precision was evaluated by intra- and inter-day tests with relative standard deviations (RSDs) < 2.0%, recovery in between 70% and 120% with RSDs < 2.00%., Conclusion: The results demonstrate that the concentration of pesticides 1 to 8 were found below the detectable limit. Method validation parameters like linearity, precision, accuracy, specificity, robustness, detection and quantification limits were found within the acceptable range. The proposed method makes it possible to determine simultaneously pesticides 1-8 in one run which can be extended for residue-based standardization of pesticides from apple and other fruits and vegetables. © 2019 Society of Chemical Industry., (© 2019 Society of Chemical Industry.)

In this study, a surface-enhanced Raman scattering (SERS) approach based on silver-coated gold nanoparticles (Au@Ag NPs) was established for rapid detection of multiple organophosphorus pesticides (triazophos and methyl-parathion) in peach fruit. The Raman enhancement of Au@Ag NPs for detecting organophosphorus pesticides was stronger than those of single Ag and Au NPs. It was revealed that core size of Au NPs was a critical parameter affecting the enhancement of Raman signals by joining two plasma resonance absorptions. The Au@Ag NPs with 26 nm Au core size and 6 nm Ag shell thickness showed significant Raman enhancement, especially by the creation of hot spots through NPs aggregation induced by connection between Au@Ag NPs and target molecules. The detection limits of triazophos and methyl-parathion in peach were 0.001 mg/kg. Good recovery (93.36 to 123.6 %) and high selectivity of the SERS activity allowed excellent precision for the detection of the triazophos and methyl-parathion in peach. Compared to earlier studies, the current approach was rapid, inexpensive and simple without lengthy sample pre-treatment. This study revealed that the proposed method could be employed for the analysis of trace contaminants such as triazophos and methyl-parathion in many food matrices.

Fast sampling and multicomponent detections are important in the analysis of pesticide residues detection. In this work, surface-enhanced Raman scattering (SERS) method based on silver-coated gold nanoparticles (Au@Ag NPs) was used to simultaneously detect multi-class pesticide residues such as thiacloprid (carbamate), profenofos (organophosphate) and oxamyl (neonicotinoid) in standard solution and peach fruit. The Au@Ag NPs with 26 nm Au core size and 6 nm Ag shell thickness exhibited significant Raman enhancement, especially by the creation of hot spots through NPs aggregation induced by the connection between Au@Ag NPs and target molecules. The findings demonstrated that the characteristic wavenumber of the pesticides (thiacloprid, profenofos, and oxamyl) could be precisely identified using the SERS method. Compared with earlier studies, the current approach was rapid, inexpensive and without lengthy sample pretreatment. Moreover, the results revealed that the limit of detection (LOD) was 0.1 mg/kg for thiacloprid obtained in the peach extract with determination coefficient (R 2 ) of 0.986. Additionally, LOD for both profenofos and oxamyl was 0.01 mg/kg with a determination coefficient (R 2 ) of 0.985 and 0.988, respectively. Good recovery percentage (78.6-162.0%) showed the high SERS activity with better accuracy for the detection of the thiacloprid, profenofos, and oxamyl in peach. The results of this study could offer a promising SERS platform for simultaneous detection of other contaminants such as thiacloprid, profenofos and oxamyl in multifaceted food matrices., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Triazophos is mainly used in Asian and African countries for the control of insects in agricultural production. Camelid variable domains of heavy-chain antibodies (VHHs) show great promise in monitoring environmental chemicals such as pesticides. To improve the rate of success in the generation of VHHs against triazophos, genes specifically encoding VHH fragments from the unique allotype IgG3a of an immunized Camelus bactrianus were amplified by using a pair of novel primers and introduced to construct a diverse VHH library. Five out of seven isolated positive clones, including the VHH T1 with the highest affinity to triazophos, were derived from the allotype IgG3a. A one-step enzyme-linked immunosorbent assay (ELISA) using VHH T1 genetically fused with alkaline phosphatase (AP) had a half-maximum inhibition concentration of 6.6 ng/mL for triazophos. This assay showed negligible cross-reactivity with a list of important organophosphate pesticides (< 0.1%). The average recoveries of triazophos from water, soil, and apple samples determined by the one-step ELISA ranged from 83 to 108%, having a good correlation with those by a gas chromatography mass spectrometry (R 2  = 0.99). The VHH-AP fusion protein shows potential for the analysis of triazophos in various matrices.

A method is described for simultaneous voltammetric determination of the pesticides triazophos (TRS) and thiacloprid (THD). A glassy carbon electrode (GCE) was modified with a metal-organic framework (type UiO-66-NH 2 ) which has a large specific surface (1018 m 2 ·g -1 ) and contains large amounts of Cd(II) and Pb(II) ions, with adsorption capacities of 230 and 271 mg·g -1 , respectively. The antigen-loaded particles were then bound to antibody, magnetically separated, and analyzed by square wave voltammetry to give signals for Cd(II) and Pb(II) at -0.82 and - 0.56 V (vs. Ag/AgCl) for TRS and THD, respectively. Under optimized conditions, the method has a wide linear range (0.2-750 ng·mL -1 ) and low detection limits (0.07 and 0.1 ng·mL -1 at a S/N of 3 for TRS and THD, respectively). It is perceived that this assay represents a useful tool for simultaneous determination of multiple pesticide residues. The method has a wide scope in that may be extended to monitoring of other small organic pollutants by changing the types of metal ions and by using other antibodies. Graphical abstract Schematic presentation of an amino-modified metal-organic framework (type UiO-66-NH 2 ) loaded with Cd(II) and Pb(II) ions for simultaneous electrochemical immunosensing of triazophos (TRS) and thiacloprid (THD). It is based on the fabrication of antigen (Ab)-immobilized UiO-66-NH 2 -based signal tags (a), and of an antibody (Ab)-immobilized magnetic bead (MB-COOH)-based capture probes (b).

Pesticides carried by cotton fiber are potential risk for production workers and consumers. Dissipation behaviour of a commonly used cotton pesticide profenofos in cotton fiber during growing period and scouring treatment was investigated. The results showed that profenofos in the fiber from the pre-opened and post-opened bolls both decreased to undetectable amounts 21 days after pesticide application. However, a minority of profenofos was converted to a strongly irritant compound, 4-bromo-2-chlorophenol and retained a non-negligible amount in cotton fiber even after 28 days. Profenofos and its degradation product could be completely removed during the conventional cotton scouring process. The degradation half-time of profenofos in scouring bath was only 3.0 min, and the degradation product was also 4-bromo-2-chlorophenol. Cotton products made of profenofos-carrying fiber are safe; however, the scouring waste should be detoxicated before discharge due to the accumulation of 4-bromo-2-chlorophenol in the scouring bath. These results could be useful for evaluating the risk of cotton fiber from the profenofos applied fields.

Organophosphorus pesticides (OPs) are commonly applied to agricultural crops. Families living in these communities may have higher exposure to OPs due to take home exposures and close proximity to agricultural fields. The objectives of this study were to measure OP concentrations in home carpet dust in agricultural and non-agricultural households and examine factors that may impact OP concentrations such as occupation, housing characteristics, and resident behaviors. Agricultural households had at least one parent who worked in agriculture during the previous 5 years. Carpet dust samples were collected at two time points from 278 households in an agricultural community located in the Pacific Northwest from 2008-2011. Samples were analyzed for four types of OPs: azinphos-methyl, phosmet, malathion, and chlorpyrifos. Overall, OP detection frequencies and concentrations were higher in agricultural households compared to non-agricultural households. Factors associated with higher OP concentrations in home carpet dust were identified and included: (1) homes with two or more agricultural workers living in the home, (2) homes located in close proximity to an agricultural field or orchard, (3) having an entry floor mat, and (4) frequently vacuuming the house. Having air conditioning in the home had a protective effect with OP concentrations. While the use of these four OPs is restricted or limited for residential use in the United States, results show that they were still found in the indoor environment. The understanding of the impact of agricultural work and other factors that elevate levels of OPs in the home is crucial to mitigating pesticide exposure in agricultural communities.

Profenofos, a highly poisonous organophosphorus pesticide, has been widely used in agricultural production. These pesticide residues have seriously influenced food security and threatened human health, and new methods with high sensitivity are greatly needed to detect profenofos. Here, we developed an aptamer-based microcantilever-array sensor operated in stress mode to detect profenofos, with advantages of being a label-free, highly sensitive, one-step immobilization method capable of quantitative and real-time detection. The microcantilevers were functionalized with a profenofos-specific aptamer (SS2-55), and then the specific binding of profenofos to aptamer induced a deflection of the microcantilever, which was monitored using an optical method in a real-time manner. The microcantilever deflection showed a positive relationship with profenofos concentration, and the detection limit was low to 1.3 ng mL -1 (3.5 nM) for profenofos, which was much lower than other aptamer-based detection methods. The selectivity of the sensor was verified with another organophosphorus pesticide. Additionally, we successfully detected profenofos dissolved in vegetable-soak solution. Our results showed that this aptamer-based microcantilever-array sensor is a convenient and label-free method for detecting profenofos in small amounts and has great potential for food-security applications., (Copyright © 2018 Elsevier B.V. All rights reserved.)

In this work, we propose an electrochemical DNA aptasensor for the detection of profenofos, an organophosphorus pesticide, based on a competitive format and disposable graphite screen-printed electrodes (GSPEs). A thiol-tethered DNA capture probe, which results to be complementary to the chosen aptamer sequence, was immobilised on gold nanoparticles/polyaniline composite film-modified electrodes (AuNPs/PANI/GSPE). Different profenofos solutions containing a fixed amount of the biotinylated DNA aptamer were dropped onto the realized aptasensors. The hybridisation reaction was measured using a streptavidin-alkaline phosphatase enzyme conjugate, which catalyses the hydrolysis of 1-naphthyl -phosphate. The 1-naphtol enzymatic product was detected by means of differential pulse voltammetry (DPV). The aptasensor showed itself to work as a signal off sensor, according to the competitive format used. A dose response curve was obtained between 0.10 &mu;M and 10 &mu;M with a detection limit of 0.27 &mu;M.

Indiscriminate use of two broad spectrum pesticides, profenofos and fenthion, in agricultural system, often results in their accumulation in a non-target niche and leaching into water bodies. The present study, therefore, aims at developing a simple and rapid HPLC method that allows simultaneous extraction and detection of these two pesticides, especially in run-off water. Extraction of the two pesticides from spiked water samples using dichloromethane resulted in recovery ranging between 80 and 90%. An HPLC run of 20 min under optimized chromatographic parameters (mobile phase: methanol (75%) and water (25%); flow rate of 0.8 ml min -1 ; diode array detector at wavelength 210 nm) resulted in a significant difference in retention times of two pesticides (4.593 min) which allows a window of opportunity to study any possible intermediates/transformants of the parent compounds while evaluating run-off waters from agricultural fields. The HPLC method developed allowed simultaneous detection of profenofos and fenthion with a single injection into the HPLC system with 0.0328 mg l -1 (32.83 ng ml -1 ) being the limit of detection (LOD) and 0.0995 mg l -1 (99.5 ng ml -1 ) as the limit of quantification (LOQ) for fenthion; for profenofos, LOD and LOQ were 0.104 mg l -1 (104.50 ng ml -1 ) and 0.316 mg l -1 (316.65 ng ml -1 ), respectively. The findings were further validated using the soil microcosm experiment that allowed simultaneous detection and quantification of profenofos and fenthion. The findings indicate towards the practical significance of the methodology developed as the soil microcosm experiment closely mimics the agricultural run-off water under natural environmental conditions.

The wide application of an organophosphate pesticide triazophos raises concern on the environmental pollution and the potential risk to human health. Thus, it is crucial to regularly monitor triazophos residue in the environment and agro-products. Herein we described a non-competitive immunoassay for trace detection of triazophos using a direct surface plasmon resonance (SPR) biosensor. Two anti-triazophos monoclonal antibodies (mAbs) were immobilized on the sensor chip and characterized by SPR-based kinetic analysis. The mAb with relatively slow dissociation rate was used for direct immunosensing of triazophos. The biosensor assay showed a high specificity and a low detection limit of 0.096ngmL -1 to triazophos, with the linear detection range of 0.98-8.29ngmL -1 . Under the optimal condition, the sensor chip could be regenerated for 160cycles at least. Moreover, the sensitive method was applied to determine triazophos in the spiked environmental water and agricultural products, as well as in unknown real-life samples (including Chinese cabbage, cucumber, and apple). Desirable results demonstrated that the newly-developed immunosensor could be used as a rapid, convenient, and reliable tool to regularly monitor triazophos and meet the detection requirement of its maximum residue limits., (Copyright © 2017. Published by Elsevier B.V.)

A simple and highly sensitive immunoassay based on a competitive binding and bio-barcode amplification was designed for detection of small molecules, triazophos. The gold nanoparticles (AuNPs) were modified with monoclonal antibodies and 6-carboxyfluorescein labeled single-stranded thiol-oligonucleotides (6-FAM-SH-ssDNAs); the fluorescence of 6-FAM was quenched by AuNPs. Ovalbumin-linked haptens were coated on the bottom of microplate to compete with the triazophos in the sample for binding to the antibodies on the AuNP probes. The fluorescence intensity was inversely proportional to analyte concentration. Parameters of AuNP probes preparation and immune reaction were optimized. At the optimal conditions, the salting process was shortened to 1 h and 166 ± 9 ssDNAs were loaded onto a single AuNP. The competitive fluorescence bio-barcode immunoassay was performed on water, rice, cucumber, cabbage and apple samples. The linear range of the method was 0.01-20 μg L -1 and the limit of detection (LOD) was 6 ng L -1 . The recovery and relative standard deviations (RSDs) ranged from 85.0 to 110.3% and 9.4-17.4%, respectively. Good correlations were obtained between the results of the developed method and liquid chromatography-tandem mass spectrometry (LC-MS/MS). In conclusion, it is suggested that the competitive fluorescent bio-barcode immunoassay had the potential to be used as a sensitive method for detection of a variety of small molecules in various samples., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Currently, the potential impact of insecticide mixtures to nontarget organisms is largely unknown, and additional study is needed. The present study investigated the mixture toxicity of the organophosphate insecticide phostebupirim and the pyrethroid insecticide cyfluthrin using 4 nontarget species including Daphnia magna, Hyalella azteca, Pimephales promelas (fathead minnow), and Danio rerio (zebrafish). For each species, the toxicity of equipotent mixtures was compared with the expected toxicity estimated using the independent action (IA) and concentration addition (CA) models. Lethal and sublethal responses to D. magna and H. azteca were best described with the IA model. For both fish species, mixture toxicity was significantly higher than that estimated using either mixture model. The synergism noted in fish exposed to the combination of phostebupirim and cyfluthrin was confirmed by exposing P. promelas larvae to a nontoxic dose of phostebupirim and a range of toxic cyfluthrin concentrations, and vice versa. Sublethal and lethal concentrations to fish were up to 7 times lower for the mixture than in concurrently run individual compound exposures. Potential mechanisms for the synergistic responses found in fish are presented. Environ Toxicol Chem 2017;36:1947-1954. © 2016 SETAC., (© 2016 SETAC.)

Since 1998, the University of Washington's Center for Child Environmental Health Risks Research has followed a community-based participatory research strategy in the Lower Yakima Valley of Washington State to assess pesticide exposure among families of Hispanic farmworkers. As a part of this longitudinal study, house dust samples were collected from both farmworker and non-farmworker households, across three agricultural seasons (thinning, harvest and non-spray). The household dust samples were analyzed for five organophosphate pesticides: azinphos-methyl, phosmet, malathion, diazinon, and chlorpyrifos. Organophosphate pesticide levels in house dust were generally reflective of annual use rates and varied by occupational status and agricultural season. Overall, organophosphate pesticide concentrations were higher in the thinning and harvest seasons than in the non-spray season. Azinphos-methyl was found in the highest concentrations across all seasons and occupations. Farmworker house dust had between 5- and 9-fold higher concentrations of azinphos-methyl than non-farmworker house dust. Phosmet was found in 5-7-fold higher concentrations in farmworker house dust relative to non-farmworker house dust. Malathion and chlorpyriphos concentrations in farmworker house dust ranged between 1.8- and 9.8-fold higher than non-farmworker house dust. Diazinon showed a defined seasonal pattern that peaked in the harvest season and did not significantly differ between farmworker and non-farmworker house dust. The observed occupational differences in four out of five of the pesticide residues measured provides evidence supporting an occupational take home pathway, in which workers may bring pesticides home on their skin or clothing. Further, these results demonstrate the ability of dust samples to inform the episodic nature of organophosphate pesticide exposures and the need to collect multiple samples for complete characterization of exposure potential.

This study was performed to identify the degradation products of profenofos "a phenyl organothiophosphate insecticide" in raw water (RW) collected from the entry point of Metropolitan Water Works Authority "Bangkaen, Thailand" and ultrapure water (UPW) with and without TiO 2 under simulated sunlight irradiation. Degradation of profenofos was followed with ultrahigh performance liquid chromatography (UHPLC) and follows pseudo first-order kinetic. Accordingly, high-field FTICR mass spectrometry coupled to an electrospray ionization source was used to reveal the degradation routes of profenofos and the isotopic fine structures (IFS) elucidations to approve the chemical structures of its degradation products. More degradation products were detected in UPW as compared to RW. Consequently, two main degradation pathways namely (i) interactive replacements of bromine and hydrogen by hydroxyl functional groups and (ii) rupture of PO, PS, CBr and CCl bonds were observed. None interactive replacement of chlorine by hydroxyl functional group was detected. Accordingly, mechanistical pathways of the main degradation products were established.

Background: Use of pesticides has been documented to lead to several adverse health effects. Farmers are likely to be exposed to pesticides through dermal exposure as a result of mixing, loading, and spraying. Organophosphate pesticides (OPs) are widely used in most of the agricultural areas throughout Thailand. OPs are cholinesterase inhibitors and blood cholinesterase activity is used as a biomarker of OP effects., Objective: This study aims to determine the association between blood cholinesterase activity and organophosphate pesticide residues on chili farmer’s hands and their adverse health effects., Materials and Methods: Ninety chili farmers directly involved with pesticide applications (e.g. mixing, loading, spraying) were recruited and were interviewed face to face. Both enzymes, erythrocyte acetylcholinesterase (AChE) and plasma cholinesterase (PChE), were tested with the EQM Test-mate Cholinesterase Test System (Model 400). Hand wipe samples were used for collecting residues on both hands and OP residues for chlorpyrifos and profenofos were quantified using gas chromatography equipped with a flame photometric detector (GC-FPD)., Results: The average activity (±SD) of AChE and PChE was 2.73 (±0.88) and 1.58 (±0.56) U/mL, respectively. About 80.0% of the participants had detectable OP residues on hands. The median residues of chlorpyrifos and profenofos were found to be 0.02 and 0.03 mg/kg/two hands, respectively. Half of participants reported having some acute health symptoms within 48 hours after applying pesticides. When adjusted for gender, number of years working in chili farming, and frequency of pesticide use, AChE activity (Adjusted OR = 0.03, 95%CI: 0.01-0.13) and detected OP residues on hands (Adjusted OR = 0.15, 95%CI: 0.02-0.95) were significantly associated with having health effects, but no significant association was found in PChE activity (Adjusted OR = 2.09, 95%CI: 0.63-6.99)., Conclusions: This study suggests that regular monitoring for blood cholinesterase and effective interventions to reduce pesticide exposure to prevent health effects should be provided to chili farmers.

Triazophos (TAP) is a widely used pesticide that is easily accumulated in the environment due to its relatively high stability: this accumulation from agricultural runoff results in potential hazards to aquatic ecosystems. Constructed wetlands are generally considered to be an effective technology for treating TAP polluted surface water. However, knowledge about the biological mechanisms of TAP removal is still lacking. This study investigates the responses of a wetland plant (Canna indica), substrate enzymes and microbial communities in bench-scale horizontal subsurface-flow constructed wetlands (HSCWs) loaded with different TAP concentrations (0, 0.1, 0.5 and 5 mg · L(-1)). The results indicate that TAP stimulated the activities of superoxide dismutase (SOD) and peroxidase (POD) in the roots of C. indica. The highest TAP concentrations significantly inhibited photosynthetic activities, as shown by a reduced effective quantum yield of PS II (ΦPS II) and lower electron transport rates (ETR). However, interestingly, the lower TAP loadings exhibited some favorable effects on these two variables, suggesting that C. indica is a suitable species for use in wetlands designed for treatment of low TAP concentrations. Urease and alkaline phosphatase (ALP) in the wetland substrate were activated by TAP. Two-way ANOVA demonstrated that urease activity was influenced by both the TAP concentrations and season, while acidphosphatase (ACP) only responded to seasonal variations. Analysis of high throughput sequencing of 16S rRNA revealed seasonal variations in the microbial community structure of the wetland substrate at the phylum and family levels. In addition, urease activity had a greater correlation with the relative abundance of some functional microbial groups, such as the Bacillaceae family, and the ALP and ACP may be influenced by the plant more than substrate microbial communities., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Surface enhanced Raman spectroscopy (SERS) and quick pre-treatment technology were used to detect triazophos residues in flesh of navel orange. Quantitative analysis model was developed by partial least squares (PLS) algorithm. SERS of different concentration (0.5 to 20 mg x L(-1)) triazophos juice solution with flesh extract as the matrix were collected by laser Raman spectrometer. Three preprocessing methods such as normalization, MSC and SNV were used to optimize Raman signals and PLS models were set up. The results showed that minimum detection concentration for triazophos in navel orange below 0.5 mg L(-1). The model built with normalization pre-processing gave the best result; the values of correlation (R(p)) and Root mean square error of prediction set (RMSEP) were 1.38 and 0.976 6, respectively. The predict recoveries were 95.97%-103.18%, and the absolute values of relative errors were below 5%. T-test (t = -0.018) showed that there was no significant difference between the true values and prediction values. This study demonstrates that this method is accurate and reliable.

The present study was carried out to observe the dissipation pattern of triazophos on capsicum and risk assessment of its residues on human beings and to suggest a waiting period for the safety of consumers. Following two applications of triazophos (Truzo 40 EC) at 500 and 1000 g a.i. ha(-1), the average initial deposits were found to be 3.61 and 6.26 mg kg(-1), respectively. These residues dissipated below the limit of quantification (LOQ) of 0.05 mg kg(-1) in 10 and 15 days at the recommended and double the recommended dosages, respectively. The calculated values of half-life were 2.31 and 2.14 days at recommended and double the recommended dosages, respectively. Theoretical maximum residue contribution (TMRC) values were found to be 28.8 and 41.6 μg person(-1) day(-1) at 500 and 1000 g a.i. ha(-1), respectively, and found to be below the maximum permissible intake on capsicum fruit on the 7th day. Therefore, a waiting period of 7 days is suggested for consumption of capsicum sprayed with triazophos at the recommended dosages.

Persistence of delltamethrin, endosulfan, and triazophos in egg plant and tomato was studied following application of two ready mix formulations of insecticides viz. deltametrhin and endosulfan (Cobra 5000; 0.75% deltamethrin + 29.5% endosulfan) and deltamethrin and triazophos (Annaconda Plus; 1% deltamethrin + 35% triazophos) at recommended (1.0 L/ha and double dose 2.0 L/ha). The residues of deltamethrin persisted till 7 and 5 days in tomato and egg plant fruits, respectively, in the ready mix formulation of Cobra 5000 whereas endosulfan persisted till 15 and 10 days in tomato and egg plant fruits, respectively. Dissipation of the insecticides followed first-order kinetics with half-life values of deltamethrin and endosulfan ranged from 2.6 to 4.7 and 1.4 to 1.7 days, respectively, for both the vegetables. In case of combination mix of deltamethrin and triazophos (Annaconda Plus), deltamethrin persisted beyond 5 days in both tomato and egg plant fruits, while triazophos persisted till 10 days in both the vegetables. Residues of deltamethrin and triazophos dissipated with half-life of 2.6-4.2 and 1.7-4.1 days, respectively, on tomato and egg plant fruits. Based on the Codex MRL limits, a safe waiting period of 5 and 3 days is suggested for tomato and egg plant, respectively, for the ready mix formulation of deltamethrin and endosulfan (Cobra 5000), and 5-day waiting period is suggested for tomato and egg plant for the combination mix of deltamethrin and triazophos.

A highly sensitive chemiluminescent enzyme immunoassay (CLEIA) method was developed in this study for efficient screening of triazophos residues in a large number of samples. Based on the maximum residue limits (MRLs) set by China and CAC for triazophos in different agro-products, the representative apple, orange, cabbage, zucchini, and rice samples were selected as spiked samples, and the triazophos at the concentrations of the MRL values were spiked to blank samples. Subsequently, the five samples with the spiked triazophos standard were measured by CLEIA 100 times, and the detection results indicated that the correction factors of the apple, orange, cabbage, zucchini, and rice were determined as 0.79, 0.66, 0.85, 0.76, and 0.91, respectively. In this experiment, 1500 real samples were detected by both the CLEIA and the GC-MS methods. With the GC-MS method, 1462 samples were identified as negative samples and 38 samples as positive samples. Based on the correction factors, the false positive rate of the CLEIA method was 0.13%, and false negative rate was 0. The results showed that the established CLEIA method could be used to screen a large number of real samples.

A 3-yr study was conducted on a corn field in central Illinois, USA, to understand the fate and effects of an insecticidal formulation containing the active ingredients phostebupirim and cyfluthrin. The objectives were to determine the best tillage practice (conventional vs conservation tillage) in terms of grain yields and potential environmental risk, to assess insecticidal exposure using concentrations measured in soil and runoff water and sediments, to compare measured insecticidal concentrations with predicted concentrations from selected risk assessment exposure models, and to calculate toxicity benchmarks from laboratory bioassays performed on reference aquatic and terrestrial nontarget organisms, using individual active ingredients and the formulation. Corn grain yields were not significantly different based on tillage treatment. Similarly, field concentrations of insecticides were not significantly (p > 0.05) different in strip tillage versus conventional tillage, suggesting that neither of the tillage systems would enable greater environmental risk from the insecticidal formulation. Risk quotients were calculated from field concentrations and toxicity data to determine potential risk to nontarget species. The insecticidal formulation used at the recommended rate resulted in soil, sediment, and water concentrations that were potentially harmful to aquatic and terrestrial invertebrates, if exposure occurred, with risk quotients up to 34., (© 2014 SETAC.)

A rapid liquid chromatography tandem mass spectrometry (LC-MS/MS) method has been developed for determination of levels of the organophosphorus (OP) pesticides chlorpyrifos (CPF), azinphos methyl (AZM), and their oxygen analogs chlorpyrifos-oxon (CPF-O) and azinphos methyl-oxon (AZM-O) on common active air sampling matrices. XAD-2 resin and polyurethane foam (PUF) matrices were extracted with acetonitrile containing stable-isotope labeled internal standards (ISTD). Analysis was accomplished in Multiple Reaction Monitoring (MRM) mode, and analytes in unknown samples were identified by retention time (±0.1 min) and qualifier ratio (±30% absolute) as compared to the mean of calibrants. For all compounds, calibration linearity correlation coefficients were ≥0.996. Limits of detection (LOD) ranged from 0.15-1.1 ng/sample for CPF, CPF-O, AZM, and AZM-O on active sampling matrices. Spiked fortification recoveries were 78-113% from XAD-2 active air sampling tubes and 71-108% from PUF active air sampling tubes. Storage stability tests also yielded recoveries ranging from 74-94% after time periods ranging from 2-10 months. The results demonstrate that LC-MS/MS is a sensitive method for determining these compounds from two different matrices at the low concentrations that can result from spray drift and long range transport in non-target areas following agricultural applications. In an inter-laboratory comparison, the limit of quantification (LOQ) for LC-MS/MS was 100 times lower than a typical gas chromatography-mass spectrometry (GC-MS) method.

Background: Chlorpyrifos and profenofos are organophosphate pesticides (OPPs), we studied exposure and urinary metabolites in an agricultural area in the northeastern of Thailand during the chili-growing season (March - April) in 2012., Objective: This study was designed to assess pesticide exposure concentration through dermal and inhalation pathways and to find and depict a relationship between urinary metabolites and means of exposure., Materials and Methods: To estimate the pesticides exposure concentration, dermal wipes (hand, face, and feet), dermal patches and air samples were collected from 38 chili farmers. The morning void of pre and post application urine samples was an indicator of biological monitoring in the study which derived from 39 chili farmers., Results: Chlorpyrifos and profenofos residues were detected on dermal patches, face wipes, and hand wipe samples, while no significant residues were found on the feet. Using a personal air sampling technique, all air samples detected pesticide residues. However, significant correlation between dermal pesticide exposure concentration and inhalation was not found (p>0.05). For urinary metabolite levels, there was a relationship between the first pre application morning void and post application morning void (p < 0.05); similar to the association between the first pre application morning void and the second post application morning void (p < 0.05). The main relationship between pesticide exposure and urinary metabolite was found to have been relevant to dermal exposure (r= 0.405; p < 0.05)., Conclusions: The results of this study could suggested that public health education training programs, including the use of appropriate personal protective equipment (PPE), should be offered for the chili growing farmers in order to improve their ability to properly use pesticides., Key Words: pesticide exposure, chili farmers, urinary metabolites, organophosphate pesticides.

Background: Pesticides used in agriculture can be taken into worker homes and pose a potential risk for children and other family members. This study focused on identification of potential intervention points at the workplace., Methods: Workers (N = 46) recruited from two tree fruit orchards in Washington State were administered a 63-item pesticide safety questionnaire. Dust was collected from commuter vehicles and worker homes and analyzed for four organophosphorus (OP) pesticides (azinphosmethyl, phosmet, chlorpyrifos, malathion)., Results: Geometric mean azinphosmethyl concentrations in dust for three worker groups (16 pesticide handlers, 15 green fruit thinners, 15 organic orchard workers) ranged from 0.027-1.5 μg/g, with levels in vehicle dust higher than in house dust, and levels in house dust from handlers' homes higher than levels from tree fruit thinners' homes. Vehicle and house dust concentrations of azinphosmethyl were highly associated (R(2) = 0.44, P < 0.001). Significant differences were found across worker groups for availability of laundry facilities, work boot storage, frequency of hand washing, commuter vehicle use, parking location, and safety training., Conclusions: These findings support a focus on intervention activities to reduce take home pesticide exposure closer to the source of contamination; specifically, the workplace and vehicles used to travel to the workplace., (Copyright © 2013 Wiley Periodicals, Inc.)

Maize seeds obtained from ¹⁴C-ethion treated plants contained about 0.01 % of the originally applied radioactivity 1 month following the last pesticide application. Hexane and methanol extracts of the seeds accounted for 35 % and 22.5 % of the radioactive residues, respectively, with 40 % remaining in the seed cake. Commercial processing procedures resulted in a gradual decrease in the total amount of ¹⁴C-residues in oils with aged residues. The refined oil contained ¹⁴C-residues that amounted to about 30 % of the amount that was originally present. The major residues in processed oil are ethion monooxon, O,O-diethyl phosphorothioate and O,O-diethyl S-hydroxymethyl phosphorodithioate, in addition to one unknown compound. After feeding rats with the cake containing ethion bound residues, a substantial amount (71 %) of ¹⁴C-residues was eliminated in the urine, while about 12 % was excreted in the feces. About 5 % of the radioactive residues were distributed among various organs. The bound residue was quite readily bioavailable to the rats.

We have developed a novel vortex-assisted surfactant-enhanced-emulsification liquid-liquid microextraction using the low density solvent for the determination of eight organophosphorus pesticides (OPPs) in water samples. The key point of this method is the application of a special home-made extraction device. The influence parameters relevant to this method were systemically investigated and the optimum conditions were as follow: 35μL of toluene was used as extraction solvent and 0.2mmol L-1 Triton X-100 was chosen as the surfactant to enhance the emulsification. Under the optimum experimental conditions, the limit of detections (LODs) of the method was ranged between 0.01 and 0.05μgL(-1) and the relative standard deviations (RSDs) were 2.9-8.1%. The calibration curve was linear in the range of 0.1-50.0μgL(-1), with the correlation coefficients (r) varying from 0.9949 to 0.9991. Finally, the developed method has been successfully applied to the determination of eight organophosphorus pesticides in river, reservoir and well water samples with recoveries between 82.1% and 98.7%., (Copyright © 2013 Elsevier B.V. All rights reserved.)

Persistence of cypermethrin, deltamethrin, profenofos, and triazophos in cauliflower curd was studied, following application of two premix formulations viz: Roket 44EC (profenofos 40 % + cypermethrin 4 %) and Anaconda Plus 36EC (triazophos 35 % + deltamethrin 1 %) at recommended (1.0 L ha(-1)) and double doses (2.0 L ha(-1)). In the case of Roket 44EC, residues of cypermethrin dissipated with the half-life values of 1.5-2.1 days, whereas residues of profenofos dissipated with the half-life of 2.9-3.3 days on cauliflower curd. In the case of Anaconda, residues of triazophos and deltamethrin dissipated from curd with the half-life values of 2.6-3.0 and 2.2-2.6 days, respectively. Both the combination mix significantly reduced the aphid population up to 14 days after spray and increased the yield by 155-160 % over control. Anaconda (2.0 L ha(-1)) treated plots yielded the highest number of marketable curds. Based on risk assessment analysis, safe waiting period of 3 and 5 days has been suggested for Roket 44EC and Anaconda Plus 36EC, respectively, in cauliflower at recommended dose of application.

The objective of this work was to establish a simple extraction method for the residual analysis of pyraclofos and tebufenpyrad in Perilla leaves. A QuEChERS (quick, easy, cheap, effective, rugged and safe) method was used for extraction using ethyl acetate as an extraction solvent, and cleanup was carried out using dispersive solid-phase extraction technique. The samples were analyzed using gas chromatography with nitrogen phosphorous detector and confirmed by gas chromatography-mass spectrometry. The linearity was excellent (r(2) = 1.0) in matrix-matched calibration for both pesticides. The recoveries at two fortification levels were 80.76-95.38% with relative standard deviation lower than 5%. The limits of detection and limits of quantification were 0.01 and 0.033 mg/kg for both pesticides, respectively. The results revealed that the dissipation pattern of pyraclofos and tebufenpyrad followed first-order kinetics. The pyraclofos and tebufenpyrad residues declined to a level below the maximum residue limits within 14 day between the last application and harvesting. We suggest that pyraclofos and tebufenpyrad could be used efficiently on perilla leaves under the recommended dosage conditions., (Copyright © 2012 John Wiley & Sons, Ltd.)

Persistence behavior of three combination mix formulations of insecticides viz. chlorpyriphos + cypermethrin (Action-505), profenofos + cypermethrin (Roket 44EC) and triazophos + deltamethrin (Anaconda) and their bioefficacy against melon fruitfly were studied in bittergourd fruits following spray application. Half-life values of the constituent insecticides calculated from first order dissipation kinetics were ~2-3 days. Based on acceptable daily intake values, safe waiting period of 3-days is suggested for all the three combination mix formulations at recommended dose of application. Anaconda (1 L/ha) was found to be most effective against Melon fruitfly as it gave 11.72 % (number/number) and 10.93 % (weight/weight) damage as compared to control 41.13 % and 41.16 %, respectively. Anaconda at lower and higher dose (1 and 2 L/ha) was not significantly different. Rocket (2 L/ha) and Action 505 (2 L/ha) were also found effective.

In this work, the use of the ionic liquid (IL) 1,3-dipentylimidazolium hexafluorophosphate ([PPIm][PF₆]) as an alternative extractant for IL dispersive liquid-liquid microextraction (IL-DLLME) of a group of pesticides and metabolites (2-aminobenzimidazole, carbendazim/benomyl, thiabendazole, fuberidazole, carbaryl, 1-naphthol, and triazophos) from soils is described. After performing an initial ultrasound-assisted extraction (USE), the IL-DLLME procedure was applied for the extraction of these organic analytes from soil extracts. Separation and quantification was achieved by high-performance liquid chromatography (HPLC) with fluorescence detection (FD). Calibration, precision, and accuracy of the described USE-IL-DLLME-HPLC-FD method using [PPIm][PF₆] as an alternative extractant was evaluated with two soils of different physicochemical properties. Accuracy percentages were in the range 93-118% with RSD values below 20%. A comparison of the performance of [PPIm][PF₆] versus that of the so-common 1-hexyl-3-methylimidazolium hexafluorophosphate ([HMIm][PF₆]) was accomplished. Results indicate a comparable extraction efficiency with both ILs, being slightly higher with [HMIm][PF₆] for the metabolite 2-aminobenzimidazole, and slightly higher with [PPIm][PF₆] for triazophos. In all cases, LODs were in the low ng/g range (0.02-14.2 ng/g for [HMIm][PF₆] and 0.02-60.5 ng/g for [PPIm][PF₆]). As a result, the current work constitutes a starting point for the use of the IL [PPIm][PF₆] for further analytical approaches., (© 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

A direct competitive chemiluminescent enzyme immunoassay (CLEIA) for triazophos was developed, which was based on the anti-THHe IgG monoclonal antibody and a heterogeneous enzyme tracer (THHu-HRP). Several components of chemiluminescent enhanced solution (CES) were optimized. The results showed that 1 mM of p-iodo-phenol, 0.625 mM of luminol, and 4 mM of H(2)O(2) had the best performance. Based on the study of CES, the influence of several factors (assay buffer, blocking substance, and solvent) on the immunoassay was investigated. The sensitivity for detection, IC(50) value was 0.87 ng/mL at a practical working concentration range between 0.04 ng/mL and 5 ng/mL and the limit of detection for triazophos was 0.063 ng/mL. The average recovery of triazophos added to lettuce, carrot, apple, water, and soil were 78.71%, 67.52%, 118.3%, 117.2%, and 122.0%, respectively. Finally, comparison between the methods of CLEIA and high-performance liquid chromatography-tandem mass spectrum (HPLC-MS/MS) was performed. The results obtained from CLEIA were in agreement with those of HPLC-MS/MS., (© 2012 Institute of Food Technologists®)

A quartz crystal microbalance (QCM) sensor based on molecularly imprinted ultra-thin films was developed for detecting profenofos in real samples. Films prepared by physical entrapment (MIP-A) and in situ self-assembly (MIP-B) were compared. The results indicated that the best sensing signal was obtained through the in situ self-assembly method. The QCM sensor chip was pretreated with 11-mercaptoundecanoic acid (MUA) to form a self-assembled monolayer (SAM), and then polymer films were immobilized directly on the SAM using surface-initiated radical polymerization. In this paper, all detection experiments were taken in air. The reaction was processed in solution, and the electrode was washed with deionized water and dried with N(2) before QCM measurement. The film was characterized by a scanning electron microscope (SEM), AC impedance and cyclic voltammetry. Analysis of the QCM response in the presence of different concentrations of profenofos showed a good linear correlation during 1.0 × 10(-8) to 1.0 × 10(-5) mg mL(-1) (y = 5log x + 42.5, R = 0.9960) and 1.0 × 10(-5) to 1.0 × 10(-3) mg mL(-1) (y = 25.86log x + 146, R = 0.9959), respectively. The MIP-QCM sensor was used to detect profenofos in tap water, and showed good recovery and repeatability.