Trace Pesticides Research Articles

In-Situ Grown Silver Nanoparticles on Nonwoven Fabrics Based on Mussel-Inspired Polydopamine for Highly Sensitive SERS Carbaryl Pesticides Detection.

The rapid sampling and efficient collection of target molecules from a real-world surface is fairly crucial for surface-enhanced Raman scattering (SERS) to detect trace pesticide residues in the environment and in agriculture fields. In this work, a versatile approach was exploited to fabricate a flexible SERS substrate for highly sensitive detection of carbaryl pesticides, using in-situ grown silver nanoparticles (AgNPs)on non-woven (NW) fabric surfaces based on mussel-inspired polydopamine (PDA) molecules. The obtained NW@PDA@AgNPs fabrics showed extremely sensitive and reproducible SERS signals toward crystal violet (CV) molecules, and the detection limit was as low as 1.0 × 10−12 M. More importantly, these NW@PDA@AgNPs fabrics could be directly utilized as flexible SERS substrates for the rapid extraction and detection of trace carbaryl pesticides from various fruit surfaces through a simple swabbing approach. It was identified that the detection limits of carbaryl residues from apple, orange, and banana surfaces were approximately decreased to 4.02 × 10−12, 6.04 × 10−12, and 5.03 × 10−12 g, respectively, demonstrating high sensitivity and superior reliability. These flexible substrates could not only drastically increase the collection efficiency from multifarious irregular-shaped matrices, but also greatly enhance analytical sensitivity and reliability for carbaryl pesticides. The fabricated flexible and multifunctional SERS substrates would have great potential to trace pesticide residue detection in the environment and bioscience fields.

Detecting and Mapping Harmful Chemicals in Fruit and Vegetables Using Nanoparticle-Enhanced Laser-Induced Breakdown Spectroscopy

Residues of harmful chemicals in fruit and vegetables pose risks to human health. Ordinary laser-induced breakdown spectroscopy (LIBS) techniques are unsatisfactory for detecting harmful chemicals in fruit and vegetables. In this study, we applied metal nanoparticles to fruit and vegetables samples to improve the ability of LIBS to detect trace pesticide and heavy metal residues in the samples. The nanoparticle-enhanced LIBS technique gave pesticide residue detection limits for fruit and vegetables two orders of magnitude lower than achieved using standard LIBS and heavy metal detection limits markedly better than achieved using standard LIBS. We used the nanoparticle-enhanced LIBS technique to study the distributions of harmful chemicals in vegetable leaves. We found that heavy metals are distributed unevenly in edible plant leaves, the heavy metal concentrations being higher in the veins than in the mesophyll.

Detection of pesticide residues on intact tomatoes by carbon fiber ionization mass spectrometry.

Trace and toxic pesticide residues may still remain on crops after harvest. Thus, maximum residual levels (MRLs) of pesticides on crops have been regulated. To determine whether the remaining pesticide residue level is below MRL, time-consuming sample pretreatment is needed prior to analysis of crop samples by suitable analytical tools. By elimination of sample pretreatment steps, a high-throughput method can be developed to determine the presence of pesticide residues directly on intact crops. Carbon fiber ionization mass spectrometry (CFI-MS) is effective in determining analytes with different polarities in solid, liquid, and vapor phases in open air. Moreover, the vapor derived from solid or liquid samples possessing high vapor pressure can be readily detected by CFI-MS. The setup of CFI-MS is straightforward. A carbon fiber (diameter of ~ 10μm and length of ~ 1cm) is placed close (~ 1mm) to the inlet of the mass spectrometer applied with a high voltage (- 4.5kV). No direct electrical contact applied on the carbon fiber is required. When placing the sample with certain vapor pressure underneath the carbon fiber, analyte ions derived from the sample can be readily detected by the mass spectrometer. Given that most pesticides possess a certain vapor pressure (~ 1.33 × 10-5-~ 1.33 × 10-4Pa), we herein develop a qualitative and quantitative analysis method to determine pesticide residues on intact fruits such as tomato based on CFI-MS without requiring any sample pretreatment. Atrazine, ametryn, carbofuran, chlorpyrifos, isoprocarb, and methomyl were selected as model samples. Low limits of detection (at nM range) were achieved for the model pesticides using the current approach. Moreover, we demonstrated that the precision and accuracy of quantitative analysis of ~ 5% and ~ 2%, respectively, could be achieved using this approach. Graphical Abstract ᅟ.

A covalently cross-linked microporous polymer based micro-solid phase extraction for online analysis of trace pesticide residues in citrus fruits.

Covalently cross-linked microporous polymers are a new class of highly cross-linked porous network materials with large surface area and potential superiority in sample pretreatment. In this work, a covalently cross-linked microporous polymer was well designed and synthesized by condensation of acylhydrazines in terephthalic dihydrazide with aldehyde groups in 1,3,5-benzenetricarboxaldehyde. The adsorption mechanism was explored and discussed based on π-π stacking interaction and steric effect. Then, a covalently cross-linked microporous polymer was employed as the adsorbent of online micro-solid-phase extraction coupled with high-performance liquid chromatography for the enrichment and analysis of trace pesticide residues in citrus fruits. The method was successfully applied to the online analysis of sugar orange and Huangdigan samples with the detection limits of 0.10-0.30 μg/kg. It was satisfactory that chlorpifos and triazophos in real sugar orange and Huangdigan samples could be actually found and quantified at concentrations of 0.20 and 0.51mg/kg, respectively. The recoveries of sugar orange and Huangdigan samples were in the range of 70.0-103 and 74.0-119% with relative standard deviations of 0.4-9.7 and 0.5-9.2% (n=3), respectively. The proposed method was accurate, reliable, and convenient for the online simultaneous analysis of trace pesticide residues in citrus fruits.

Multi-residue method for trace pesticide analysis in soils by LC-QQQ-MS/MS and its application to real samples

ABSTRACTA method for the simultaneous determination of 30 pesticides residues in soil was developed and validated. Among the studied agrochemicals, there are herbicides (auxines, sulfonylureas, fops, imidazolinones), fungicides (azoles) and insecticides (organophosphorus) widely used in extensive agricultural activities in Uruguay. Five methods with different extraction times, type and amount of solvent, as well as the possibility of a clean-up step were compared in terms of percentage of recovery and repeatability. The final method was based on the extraction of the pesticides’ residues from soil using two successive solvent extraction steps. First, the soil was extracted with methanol in an orbital shaker for 4 h. Secondly, the solid residue was re-extracted overnight with ultrapure water. The methanolic extract was concentrated under vacuum, whereas the aqueous solution was passed through an OASIS HLB® cartridge, eluted with an appropriate solvent and concentrated under nitrogen stream. Both extracts were finally combined and analysed by LC-QQQ-MS/MS using the Document SANTE/11,945/2015 criteria. Recovery percentages at 1 and 10 μg kg−1 for the studied compounds were in the range 70106% with relative standard deviations below 19 %. The quantification was performed using matrix-matched calibration curves as some compounds presented very strong signal suppression. Residuals of the matrix-matched calibration curves were below 20% for all the validated analytes. The quantification limit was1 μg kg−1. The method also allows the screening of 11 pesticides in soil. Sixty-five real samples collected from regions where the use of pesticides is intensive were analysed. Quinclorac, tebuconazole, penoxsulam and clomazone were the most frequently pesticides detected.

Rational Integration of Biomineralization, Microbial Surface Display, and Carbon Nanocomposites: Ultrasensitive and Selective Biosensor for Traces of Pesticides

AbstractNowadays, the over misuse of organophosphate pesticides (OPP) has seriously threatened human health and environment, and it is challenging and indispensable to establish biosensor for supersensitive, reliable, and fast detection of traces of OPP in real samples. This work provides an interdisciplinary strategy for the construction of electrochemical OPP biosensor with supersensitivity, high selectivity, simple operation, and fast response. First, amino acid ionic liquid (AAIL) is used as stabilizer to dramatically improve the dispersibility of carbon nanotube (CNT) in the water phase, so that the obtained CNT@AAIL composites show good conductivity, biocompatibility, and electrocatalytic activity. Further, CNT@AAIL composites are employed to improve the conductivity and electrochemical activity of mineralized organophosphate hydrolase (OPH)‐fused cell (M‐Cell) with excellent catalytic activity for the fabrication of electrochemical biosensor. Based on synergistic effects of CNT@AAIL and M‐Cell, the constructed biosensor shows 2–8 orders of magnitude lower limit of detection (3 fmol L−1) than those of reported OPP analytic methods. In addition, due to the specificity of OPH and detection at negative potential, the biosensor shows excellent selectivity. In addition, the biosensor also demonstrates the acceptable reliability for the traces of pesticides in real samples. This work will open an interdisciplinary avenue for supersensitive electrochemical biosensor.

Response of Diamesa spp. (Diptera: Chironomidae) from Alpine streams to newly emergent contaminants and pesticides

Acute toxicity and genotoxic activity of 11 pollutants were investigated in wild populations of Diamesa cinerella and Diamesa zernyi (Diptera Chironomidae) from two alpine streams (Italian Alps). D. cinerella was collected in two sites on the non-glacial Vermigliana stream, 50 m-upstream and 5-m downstream of the Wastewater Treatment Plant (WTP) at the Tonal Pass (1799 m a.s.l.). D. zernyi was collected in the Presena glacial stream, close to the glacier snout (2685 m a.s.l.). IV-instar larvae were exposed for 24-96 h to increasing concentrations of three drugs (ibuprofen-IBU, furosemide-FUR, trimethoprim-TMP), three personal care products (triclocarban-TCC, tonalid-TON, sucralose-SUCR), and five pesticides (boscalid-BOS, captan-CAP, chlorpyrifos-CPS, metolachlor-MET, terbuthylazine-TER). The experimental concentrations were from one to several million times higher than the highest environmental concentration (EC) measured in the study sites. Two mixtures of pesticides were also prepared: MIX 1K =103 x EC of CPS, MET and TER, and MIX 10K = 104 x EC of CPS, MET and TER. Species- and site-specific responses were observed for both tests. On the basis of survival data, both species resulted very resistant to pharmaceuticals (mainly to FUR for which no effects on survival and movement or pupation were observed), and more sensitive to pesticides (mainly to CPS, MET and CAP). Genotoxicity tests (Comet assay) highlighted a WTP effect under natural conditions and a genotoxic effect for 9 of the 11 tested compounds. Overall, a clear gradient of increasing resistance in larvae from the least (PR0) to the most polluted (TP_dw) site was highlighted by both tests, ecotoxicological and of genotoxicity, as also expected according to species autecology (D. zernyi is restricted to very cold and pristine habitats). D. cinerella living downstream of the effluent accumulates a significantly higher DNA damage than the other populations, highlighting a basal physiological stress condition in nature. It is plausible that these larvae possess chemical resistance strategies to survive already under natural conditions. Diamesa spp. exhibited a higher toxic resistance than any other model species tested to date under the same pollutants, probably associable to its strong cold resistance. The results emphasised that the measured concentrations of Contaminants of Emerging Concern (CECs) and pesticides seem to be far below those required to cause acute effects. However, the effects on freshwater communities of prolonged exposure to mixture of trace CECs and pesticides remain unknown.

Gold nanochestnut arrays as ultra-sensitive SERS substrate for detecting trace pesticide residue

In comparison to conventional spectroscopic techniques based on chromatography, surface-enhanced Raman spectroscopy (SERS) enables the rapid identification and detection of trace pesticide residues present in trace amounts in the environment and foods. Herein, a facile approach to fabricate unique gold nanochestnuts (GNCs) as an ultra-sensitive SERS substrate for detecting trace pesticide residues has been developed based on anodic aluminum oxide (AAO) templates. The GNCs are synthesized through the galvanic replacement of Ag on the top of Ni nanorod arrays. The as-prepared GNCs have well-controlled structural parameters, and importantly have unique anisotropic morphologies that benefit the enhancement in SERS performance. As a result, rhodamine 6 G (R6G) can be efficiently detected with GNCs as the SERS substrate even with a concentration of only 10−12 M, and the Raman enhancement factor reaches up to 5.4 × 109 at this concentration. Further SERS measurement of thiram indicates a remarkable SERS-active sensitivity of the as-prepared GNCs with a detection limit of thiram up to 10−14 M. The GNCs also exhibit a high signal-to-noise ratio.

Synthesis of flexible and stable SERS substrate based on Au nanofilms/cicada wing array for rapid detection of pesticide residues

A kind of flexible and stable Au nanofilms/cicada wing (Au NF/CW) nanocomposite with high surface-enhanced Raman scattering (SERS) performance was synthesized via a facile magnetron sputtering technique. By varying the sputtering time, optimal SERS substrate with sputtering time of 35 min (Au NF/CW-35) was obtained. The limit of detection (LOD) for Rhodamine 6G (R6G) was evaluated at 10−8M and the maximum value of enhancement factor (EF) was 2.20×106. Moreover, Raman intensity of R6G reduced only by 10.94% after aging for 60 days and the relative standard deviation (RSD) values were lower than 13%. The Au NF wrapped SERS substrates exhibited a high sensitivity, stability and reproducibility for analyte, which demonstrating an application potential in trace detection. Therefore, the SERS technique based on Au NF/CW-35 substrate was applied to solve the urgent problems of pesticide residues on fruit peels and the LOD for acephate was 10−9 mg/ml on pear peels via a simple “pasted and peeled off” approach. The high linear dependence indicated that Au NF/CW-35 substrate not only offered a wide potential application for rapid and quantitative detection of trace pesticide residues on real samples but also provided new ideas for bionics.

Эффективность применения продуктов переработки биогазовой установки в тепличном хозяйстве

The article describes the results of scientific research on the study of chemical composition of solid products of poultry manure processing in a biogas plant LLC “NPO “Agrobiogaz”, St. Petersburg. Biofertilizer has the structure of semi-decomposed peat, it disperses well, has a faint smell of manure. 1 ton of natural substance contains, an average, 16.5 kilogram per ton of total nitrogen, 20 kilogram per ton of total phosphorus, and about 16 kilogram per ton of total potassium, as well as microelements. The content of heavy metals within the requirements; there are no traces of pesticides.

Химический состав твердой фракции продуктов биогазовой установки ООО «НПО «Агробиогаз»

The article describes the results of scientific research on the study of chemical composition of solid products of poultry manure processing in a biogas plant LLC “NPO “Agrobiogaz”, St. Petersburg. Biofertilizer has the structure of semi-decomposed peat, it disperses well, has a faint smell of manure. 1 ton of natural substance contains, an average, 16.5 kilogram per ton of total nitrogen, 20 kilogram per ton of total phosphorus, and about 16 kilogram per ton of total potassium, as well as microelements. The content of heavy metals within the requirements; there are no traces of pesticides.

Responses of macroinvertebrate communities to pesticide application in irrigated rice fields.

The ability to recover to original states after disturbances makes macroinvertebrates useful tools for assessing the impacts of pesticides. Many studies showed that direct exposure to pesticides decreases macroinvertebrate richness and alters their composition. The main objective of this study was to assess recovery patterns in macroinvertebrate communities after pesticide application in irrigated rice fields. We analyzed short-term temporal dynamics of macroinvertebrate communities after application of the herbicides bispyribac-sodium and clomazone and the insecticide chlorantraniliprole, over the rice-growing season in southern Brazil. We selected three conventional rice fields and the recovery of macroinvertebrate communities was also compared with three adjacent natural ponds. The study was developed from November 2011 to February 2012 (rice-growing season). Five macroinvertebrate collections were carried out 3, 7, 14, 38, and 60days after pesticide application (November 25). Rice fields showed lower richness and abundance than ponds in the period immediately after pesticide application, and recovery rates in the richness of macroinvertebrate communities were more conspicuous as pesticide residuals dissipated from the fields. Macroinvertebrate community structure in rice fields also became more similar to natural ponds as pesticide traces were scarcer. However, macroinvertebrate abundance patterns were not related to pesticide concentrations in the fields. Our results supported the general hypothesis on the negative effects of pesticide application on macroinvertebrate community in irrigated rice fields, although other environmental features (e.g., length of the flooded period) also contributed to explain temporal dynamics in the macroinvertebrate communities from irrigated rice fields.

Occurrence of Pesticides and PPCPs in Surface and Drinking Water in Southern Brazil: Data on 4-Year Monitoring

This study evaluated the environmental occurrence of fifty-one pesticides, pharmaceuticals and personal care products (PPCPs) in surface and drinking water samples collected in southern Brazil over a 4-year period. The method used involved a stage based on solid-phase extraction, followed by liquid chromatography tandem mass spectrometry. Thirty compounds were detected (22 different pesticides and 8 PPCPs) and at least four compounds were identified in more than 50% of the samples. Atrazine was the most frequently detected pesticide and it was found at concentrations between 5 and 49 ng L-1. From PPCPs, glibenclamide, methylparaben and nimesulide were the most commonly detected in both drinking water and surface water samples. Results showed the extent to which traces of pesticides and PPCPs were present in water samples from this region.

Tunable porous silver nanostructures for efficient surface-enhanced Raman scattering detection of trace pesticide residues

Silver porous nanostructures with tunable porosity were fabricated as an excellent enhancing substrate for SERS detection of trace pesticide residues.

Trace determination of carbamate pesticides in medicinal plants by a fluorescent technique

The safety issue of using carbamate pesticides in medicinal plants (MPs) has been a global concern and hence attracted attention of many researchers to develop analytical tools for trace pesticides detection. Derived from the fluorescence-based techniques, a rapid, convenient and efficient method for the detection of three carbamate pesticides, including carbofuran, aldicarb and methomyl has been developed by using core-shell QDs. By optimizing experimental parameters, the system demonstrated high detection sensitivities for the investigated carbamates, with the lowest detectable concentrations less than 0.05 μM. The molecular docking study indicated that the selected carbamate pesticides bound to the catalytic active site of acetylcholinesterase via π-π or H-π interactions, which also revealed the potential mechanism of the differences in inhibition strength among the three pesticides on AChE. Moreover, in order to investigate the applicability and reliability of the proposed method for the pesticide analysis in real sample with complex matrix, the matrix effects of eight common MPs have been systematically explored. These findings suggested that this technique was a simple, sensitive and reliable method for rapid determination of carbamate pesticides in real samples, especially those with complex matrices like MPs, vegetables, fruits, and other agricultural crops.

Biological endpoints in earthworms (Amynthas gracilis) as tools for the ecotoxicity assessment of soils from livestock production systems

Due to the intensification and modernization of livestock farming practices, large amounts of trace metals, veterinary pharmaceuticals and pesticide residues are released to the soil along with animal feces. Hence, there is an increasing concern about the effects of pollutants derived from livestock activities on soil organisms. The objective of this study is to assess the ecotoxicity of soils from livestock production systems using a set of validated tissue and cellular biomarkers of non-native earthworms (Amynthas gracilis) exposed ex situ to real contaminated livestock soils.Overall, the results showed that livestock pollutants present clear environmental risks, since the exposure during 14days to soils from livestock systems triggered significant sub-lethal effects in A. gracilis, revealed by the increase of acetylcholinesterase activity in earthworms’ tissues (from 34.15±0.79 to 62.74±2.10nmol of acetylthiocholine hydrolyzed min−1mg−1 of protein), the decrease of antioxidant defense associated enzymes (superoxide dismutase activity, from 2.76±0.11 to 1.90±0.04Umg−1 of protein) and of lysosomal integrity (neutral red uptake, from 113.00±4.81 to 83.73±2.25%). Moreover, coelomocytes of earthworms exposed to the livestock soil displayed significantly higher DNA damage values (comet assay, from 126.67±8.67 to 199.67±23.15 GDI).This study validates the applicability of the tested biomarkers as early warning tools to assess sub-lethal toxicity to organisms inhabiting soil impacted by livestock pollutants. This study also highlights the relevance of A. gracilis as a suitable sentinel species to provide an integrative and more ecologically relevant response of soil ecosystem health in livestock production systems.

Chemical Evaluation of Electronic Cigarettes: Multicomponent Analysis of Liquid Refills and their Corresponding Aerosols

Electronic cigarette use has raised concern worldwide regarding potential health risks and its position in tobacco cessation strategies. As part of any toxicity assessment, the chemical characterization of e-liquids and their related vapors are among fundamental data to be determined. Considering the lack of available reference methods, we developed and validated several analytical procedures in order to conduct a multicomponent analysis of six e-liquid refills and their resultant vapor emissions (generated by a smoking machine), and compared them with tobacco smoke. We combined several techniques including gas-chromatography, high and ultra-performance liquid chromatography and inductively coupled plasma with mass spectrometry or ultraviolet and flame ionization detection in order to identify the main e-liquid constituents (propylene glycol, glycerol and nicotine), as well as multiple potentially harmful components (trace elements, polycyclic aromatic hydrocarbons (PAHs), pesticides and carbonyl compounds). Regarding propylene glycol, glycerol and nicotine concentrations, the six tested e-liquids comply with the advertised composition and contain only traces of pollutants. Noticeable lower concentrations of trace elements (≤3.4 pg/mL puff), pesticides (<LOQ), PAHs (≤4.1 pg/mL puff) and carbonyls (≤2.11 ng/mL puff) were measured in e-vapors compared to those in cigarette smoke (up to 45.0 pg/mL puff, 8.7 pg/mL puff, 560.8 pg/mL puff and 1540 ng/mL puff, respectively). Although an accurate characterization of electronic cigarette emissions requires further analytical optimizations, our results have shown that vaping exposes the user to lesser amounts of selected toxic components of concern found in some representative French e-cigarette products than does smoking typical conventional cigarettes.

Elemental, Isotopic, and Pesticide Analysis of Wild and Cultivated Berries

ABSTRACTThe focus of this study was to investigate differences in isotopic, elemental, and trace pesticide concentrations of wild and cultivated berries from Transylvania. To emphasize differences based on geographical origin, stable isotopic ratios of 2H/1H, 18O/16O, and 13C/12C were determined by isotopic ratio mass spectrometry. Elemental fingerprinting of berries was performed by inductively coupled plasma mass spectrometry. The determination of trace pesticides in berries was performed by gas chromatography–mass spectrometry. Differences between wild and cultivated berries were evaluated using multivariate statistical analysis. The results suggest that multielemental, isotopic, and trace pesticide fingerprinting is feasible for sample differentiation.

Application of an organometallic reagent sodium nitroprusside for the detection of organophosphate insecticide monocrotophos

Organometallic compounds find wide applications such as in catalyses, syntheses, and also in biochemistry. Some of them can be used for the analysis of trace quantities of organic compounds which are regarded as toxic to human beings. Many pesticides have very low lethal dose (LD50) which could be fatal to humans, even in small quantities. The traces of many pesticides are being reported to be present in vegetables, fruits, and even in processed foods. Monocrotophos is one such pesticide which is approved for use in India and has caused many suicidal and accidental poisoning cases. Thus, a simple and sensitive method was necessary for its detection. We, in this study, reveal the application of sodium nitroprusside for the analysis of monocrotophos using a novel reaction with simple, cost-effective, but fast and reliable thin-layer chromatography technique.

A review of diffuse pollution modeling and associated implications for watershed management in China

Purpose Diffuse pollution has been extensively studied in China from loading assessments to watershed management, which are important in international research. However, few studies that assess the advances of diffuse pollution modeling and studies of trace diffuse pollutants have been conducted. The adaption and development of imported model systems based on local observations and climatic features have improved study skills and presented unique characteristics. In addition to traditional diffuse pollutants (e.g., nitrogen and phosphorus), modeling trace heavy metals and pesticide also provides insights for watershed management.