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The Science of the Total Environment Jun 2021The presence of carcinogenic N-nitrosamines and dissolved organic matter (DOM) in freshwater is a significant concern from the perspective of public health and drinking...
The presence of carcinogenic N-nitrosamines and dissolved organic matter (DOM) in freshwater is a significant concern from the perspective of public health and drinking water treatment plant operation. This study investigated the N-nitrosamines concentration and their precursors' distributions, and DOM composition in four reservoirs located in a southern city of China. A total of 22 renowned precursors were identified. Precursors from industrial and pharmaceutical origins were found to be dominant in all reservoirs; however, traces of pesticide-based precursors, i.e. pirimicarb and cycluron were also found. The distribution of nine N-nitrosamines was substantially different among the reservoirs. N-Nitrosodibutylamine (NDBA), N-Nitrosopiperidine (NPIP), N-Nitrosodimethylamine (NDMA), and N-Nitrosopyrrolidine (NPYR) were abundantly present in all reservoirs. Most of N-nitrosamines except NDMA and N-nitrosodiethylamine (NDEA) were far below the generally accepted cancer risk of 10, and NDMA/NDEA were found close to the risk level (10). Anthropogenic DOM was dominant in three reservoirs as depicted by a higher biological index (BIX) than the humification index (HIX). By the principle component analysis, BIX appeared as an indicator of N-nitrosamines (except NDEA and NPIP). A strong and direct relationship was observed between the NDMA-formation potential (FP) and concentration of total N-nitrosamines (∑NA), and BIX. These results confirmed that the anthropogenic activities were the leading source of DOM and N-nitrosamines in this city based on land-use.
PubMed: 33548708
DOI: 10.1016/j.scitotenv.2021.145409 -
Analytical Methods : Advancing Methods... Oct 2022Carbamate (CB) pesticides possess potential carcinogenic and mutagenic activities towards humans even at very low dosages. Thus, broad-specificity probes with high...
Carbamate (CB) pesticides possess potential carcinogenic and mutagenic activities towards humans even at very low dosages. Thus, broad-specificity probes with high sensitivity and speed are needed for multiple CB determination. This study is the first to focus on Dy ions-coordinated self-assembly on a silica core using a surface imprinting procedure, for the simultaneous fluorometric detection of residues of metolcarb (MC) and pirimicarb (PC) insecticides. A simple and mild solvothermal method was applied for the preparation of fluorescent imprinted microspheres starting from 1,10-phenanthroline (Phen)-ligated Dy ions to guide imprinted self-assembly of chitosan (CTS), glutaraldehyde (GA), and two carbamate pesticides (MC and PC) on the silica surface by means of coordinate bonds and hydrogen bonds. The as-prepared microspheres displayed strong fluorescence emissions the antenna effect derived from the Phen ligand and the Schiff base oligomers for sensitizing the Dy ions. An expanded in-depth mechanism study was performed on the fluorescence enhancement involving Förster resonance energy transfer (FRET) from the pesticides (donor) to the acceptor. A linear increase in fluorescence at 483 nm for MC and 574 nm for PC upon the imprinted microspheres was observed under the same 350 nm excitation wavelength. Moreover, the quantitative recognition process could be carried out simultaneously and tolerate strong distractions both from five other similar carbamate insecticides and from complicated matrices (, an extract of Ramat). The detection limit was 4 ng mL with a range of 10-60 ng mL for MC and 0.4 ng mL with a range of 1-30 ng mL for PC. Further characterization of the material, including TEM, SEM, XPS, and FTIR, Raman, and fluorescence spectra, verified that the Dy ions play a decisive role in promoting imprinted self-assembly around the silica core. Hence, a novel polynuclear Ln-organic imprinted probe having high selectivity, stability, and sensitivity for the detection of two carbamate insecticides is presented in this study.
Topics: Humans; Silicon Dioxide; Microspheres; Molecular Imprinting; Insecticides; Pesticides; Carbamates
PubMed: 36197096
DOI: 10.1039/d2ay01269c -
Analytical Methods : Advancing Methods... Nov 2022Zeolitic imidazolate framework-8 modified magnetic halloysite nanotube (MHNTs@ZIF-8) composites were synthesized and evaluated for the first time as an efficient sorbent...
Zeolitic imidazolate framework-8 modified magnetic halloysite nanotube-based solid phase extraction for the analysis of carbamate pesticides by ultra-high performance liquid chromatography tandem mass spectrometry.
Zeolitic imidazolate framework-8 modified magnetic halloysite nanotube (MHNTs@ZIF-8) composites were synthesized and evaluated for the first time as an efficient sorbent for the magnetic solid-phase extraction (mSPE) of carbamate pesticides (CPs) from water samples. MHNTs were prepared by coprecipitation, and MHNTs@ZIF-8 composites were assembled at room temperature. After characterization, MHNTs@ZIF-8 was used to extract pirimicarb, propoxur, carbaryl, isoprocarb and fenobucarb π-π stacking interaction and hydrophobic interaction between the imidazole skeleton of ZIF-8 and benzene rings or benzene-like rings in CPs, as well as the hydrogen bond formed between O in CPs and H in ZIF-8. The effects of the amount of sorbent, ionic strength, type and volume of desorption solvent and adsorption/desorption time were investigated. Under optimum conditions, good linearity was obtained for the analysis of CPs by ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) with ≥ 0.9992. The limits of quantification range from 3 to 40 ng L in water. Relative standard deviations (RSDs) were <7%, = 5, within a batch and <9% among batches. The spiked recoveries were between 81 and 104%. The proposed method has been successfully applied to the determination of CPs in various water samples.
Topics: Chromatography, High Pressure Liquid; Zeolites; Tandem Mass Spectrometry; Clay; Benzene; Water Pollutants, Chemical; Solid Phase Extraction; Pesticides; Carbamates; Esters; Nanotubes; Water; Magnetic Phenomena
PubMed: 36342027
DOI: 10.1039/d2ay01228f -
Environmental Monitoring and Assessment Jul 2017The supervised field trials were conducted in a commercial apple orchard in 2016. The trials were an attempt to determine a model for dissipation and toxicological...
The supervised field trials were conducted in a commercial apple orchard in 2016. The trials were an attempt to determine a model for dissipation and toxicological evaluation of fluopyram, tebuconazole, captan, tetrahydrophthalimide (THPI), pirimicarb, spirodiclofen, and boscalid residues detected in fruit of Red Jonaprince, Lobo, and Gala varieties immediately before harvest. The analysis also covered amounts of pesticides still present in remnants of calyx in Lobo and Gala varieties immediately before harvest. Laboratory samples of ripe apples were collected within 14 days of the treatment. Levels of pesticide residues detected in the samples changed at a constant exponential rate, and the residue levels found in ripe apples of Red Jonaprince, Gala, and Lobo varieties immediately before harvest were below maximum residue levels (MRL). Overall, captan residues in remnants of calyx were at a level of 22.3% for the Gala variety and 9.3% for the Lobo variety. Likewise, the long-term daily intake of the detected substances by a Polish adult consumer was low, ranging from 0.02% ADI for pirimicarb to 0.72% ADI for captan.
Topics: Benzamides; Captan; Crop Protection; Environmental Monitoring; Food Contamination; Fruit; Humans; Malus; Pesticide Residues; Pesticides; Phthalimides; Poland; Pyridines; Triazoles
PubMed: 28646436
DOI: 10.1007/s10661-017-6057-5 -
Analytica Chimica Acta Mar 2022An effective extraction procedure based dispersive solid phase extraction was developed for the extraction of different pesticides (dimethoate, imidacloprid, pirimicarb,...
Development of dispersive solid-liquid extraction method based on organic polymers followed by deep eutectic solvents elution; application in extraction of some pesticides from milk samples prior to their determination by HPLC-MS/MS.
An effective extraction procedure based dispersive solid phase extraction was developed for the extraction of different pesticides (dimethoate, imidacloprid, pirimicarb, carbaryl, fenitrothion, hexythiazox, and phosalone) from milk samples. The analytes were determined by high performance liquid chromatography-tandem mass spectrometry. In this method, an organic polymer (polystyrene) was dissolved in a water-miscible organic solvent (tetrahydrofuran) and it was injected into the aqueous phase obtained from milk sample after deprotonation. By this action the sorbent (polymer) was precipitated and dispersed in the solution as tiny particles. By doing so, the pesticides were adsorbed onto the sorbent. After that, the sorbent was separated by centrifugation and the adsorbed analytes were eluted by tetrabutylammonium chloride: dichloroacetic acid deep eutectic solvent. After optimization, the method validation was followed according to Food and Drug Administration and International Research Council guidelines and the results showed that wide linear ranges (0.93-500 ng/mL) and low limits of detection (0.09-0.27 ng/mL) and quantification (0.31-0.93 ng/mL) were obtained. Extraction recoveries and extraction and enrichment factors were in the ranges of 81-94% and 162-188, respectively. Relative standard deviations were less than 9% for intra- (n = 6) and inter-day (n = 6) precisions at three concentration of 2, 5, and 25 ng mL of each analyte. The developed method was successfully applied to twenty cow milk samples for determination of the pesticides.
Topics: Animals; Chromatography, High Pressure Liquid; Deep Eutectic Solvents; Liquid Phase Microextraction; Milk; Pesticides; Polymers; Solid Phase Extraction; Solvents; Tandem Mass Spectrometry
PubMed: 35227380
DOI: 10.1016/j.aca.2022.339570 -
Nanomaterials (Basel, Switzerland) Aug 2022A three-steps sol-gel method was used to obtain a CuO/SnO/WO heterostructure powder, deposited as film by spray pyrolysis. The porous morphology of the final...
A three-steps sol-gel method was used to obtain a CuO/SnO/WO heterostructure powder, deposited as film by spray pyrolysis. The porous morphology of the final heterostructure was constructed starting with fiber-like WO acting as substrate for SnO development. The SnO/WO sample provide nucleation and grew sites for CuO formation. Diffraction evaluation indicated that all samples contained crystalline structures with crystallite size varying from 42.4 Å (CuO) to 81.8 Å (WO). Elemental analysis confirmed that the samples were homogeneous in composition and had an oxygen excess due to the annealing treatments. Photocatalytic properties were tested in the presence of three pesticides-pirimicarb, S-metolachlor (S-MCh), and metalaxyl (MET)-chosen based on their resilience and toxicity. The photocatalytic activity of the CuO/SnO/WO heterostructure was compared with WO, SnO, CuO, CuO/SnO, CuO/WO, and SnO/WO samples. The results indicated that the three-component heterostructure had the highest photocatalytic efficiency toward all pesticides. The highest photocatalytic efficiency was obtained toward S-MCh (86%) using a CuO/SnO/WO sample and the lowest correspond to MET (8.2%) removal using a CuO monocomponent sample. TOC analysis indicated that not all the removal efficiency could be attributed to mineralization, and by-product formation is possible. CuO/SnO/WO is able to induce 81.3% mineralization of S-MCh, while CuO exhibited 5.7% mineralization of S-MCh. The three-run cyclic tests showed that CuO/SnO/WO, WO, and SnO/WO exhibited good photocatalytic stability without requiring additional procedures. The photocatalytic mechanism corresponds to a Z-scheme charge transfer based on a three-component structure, where CuO exhibits reduction potential responsible for O production and WO has oxidation potential responsible for HO· generation.
PubMed: 35957078
DOI: 10.3390/nano12152648 -
Foods (Basel, Switzerland) Aug 2023In this study, a new approach to pesticide permeation through the apple peel into the pulp is discussed. The tested compounds can be classified, based on mode of action,...
In this study, a new approach to pesticide permeation through the apple peel into the pulp is discussed. The tested compounds can be classified, based on mode of action, as systemic (boscalid, cyprodinil, pirimicarb, propiconazole and tebuconazole) or contact (captan, cypermethrin and fludioxonil) pesticides. The barrier effect was assessed using a Franz flow-type vertical diffusion cell system. A residue analysis was performed using a modified quick, easy, cheap, efficient, rugged and safe (QuEChERS) extraction method coupled to gas chromatography with tandem mass spectrometry (GC-MS/MS). The limits of detection (LODs) ranged between 2.6 µg kg (pirimicarb) and 17 µg kg (captan), with the coefficient of variability (CV) lower than 6%, while recoveries ranged from 85% (boscalid) to 112% (captan) at 0.1 and 1 mg kg spiked levels. The highest peel penetration was observed for pirimicarb, captan and cyprodinil, with cumulative permeations of 90, 19 and 17 µg cm, respectively. The total absorption was in the range from 0.32% (tebuconazole) to 32% (pirimicarb). Only cypermethrin was not quantitatively detected in the pulp, and its use can be recommended in crop protection techniques. The obtained results indicate that molecular weight, octanol-water partition coefficient and water solubility are important parameters determining the process of pesticide absorption.
PubMed: 37685153
DOI: 10.3390/foods12173220 -
Environmental Science and Pollution... Jun 2019Insecticide spray in fruit gardens is a very common practice in different districts of Pakistan. These toxic sprays not only deteriorate the taste of fruit but also due...
Insecticide spray in fruit gardens is a very common practice in different districts of Pakistan. These toxic sprays not only deteriorate the taste of fruit but also due to wet deposition travel through soil, they reach groundwater via leaching process. In the present study, imidazolium-based ionic liquid ([Cim][CHNH]Br) and its cellulose acetate-supported membrane ([CA-Cim][CHNH]Br) was prepared and characterized using FTIR, XRD, and SEM. These materials are used as adsorbents for the removal of "Pirimicarb" (an insecticide from waste water). A closed batch at varying parameters, i.e., concentration and temperature as function of time, was conducted on UV-Vis spectrophotometer. Comparison of removal capacity exposed better (74%) adsorption trend by CA-IL membrane than ionic liquid (68%). Thermodynamic studies projected spontaneous process (-ΔG), favoring endothermic reaction (ΔH, ΔS). Kinetics supported pseudo-second order reaction while fitness of isothermic models (Langmuir, Freundlich, Temkin) proposed multistep intraparticle diffusion process.
Topics: Adsorption; Carbamates; Cellulose; Ionic Liquids; Ions; Kinetics; Pakistan; Pyrimidines; Temperature; Thermodynamics; Wastewater; Water Pollutants, Chemical
PubMed: 30980372
DOI: 10.1007/s11356-019-04681-6 -
Journal of Environmental Quality Jul 2016Pesticides stored at or close to the soil surface after field application can be mobilized and transported off the field when surface runoff occurs. The objective of our...
Pesticides stored at or close to the soil surface after field application can be mobilized and transported off the field when surface runoff occurs. The objective of our study was to quantify the potential pesticide losses in surface runoff from a conventionally managed agricultural field in a Swedish climate. This was achieved by measuring surface runoff volumes and concentrations in runoff of six spring-applied pesticides and autumn-applied glyphosate and its metabolite aminomethylphosphonic acid (AMPA). Measurements were performed for 3 yr both during the growing seasons and during intervening winter snowmelt periods on a clay loam field close to Uppsala. During growing seasons, surface runoff was generated on only five occasions during one 25-d period in 2012 when the infiltration capacity of the soil may have been reduced by structural degradation due to large cumulative rainfall amounts after harrowing. Concentrations in surface runoff exceeded Swedish water quality standards in all samples during this growing season for diflufenican and pirimicarb. Surface runoff was generated during three snowmelt periods during the winter of 2012-2013. All of the applied pesticides were found in snowmelt samples despite incorporation of residues by autumn plowing, degradation, and leaching into the soil profile during the period between spraying and sampling. Concentrations of glyphosate ranged from 0.12 to 7.4 μg L, and concentrations of AMPA ranged from 0 to 2.7 μg L. Our results indicate that temporal changes in hydraulic properties during the growing season and when the soil freezes during winter affect pesticide losses through surface runoff.
Topics: Aluminum Silicates; Clay; Pesticides; Soil; Sweden; Water Movements; Water Pollutants, Chemical
PubMed: 27380086
DOI: 10.2134/jeq2015.10.0528 -
Environmental Science and Pollution... Nov 2015Tomato (Lycopersicon esculentum Mill.) becomes one of the world's foremost vegetables, and its world production and consumption have increased fairly quickly. The...
Tomato (Lycopersicon esculentum Mill.) becomes one of the world's foremost vegetables, and its world production and consumption have increased fairly quickly. The capacity to induce oxidative stress in tomato plant, exposed to three xenobiotics such as alpha-cypermethrin, chlorpyriphos, and pirimicarb, was investigated by the evaluation of lipid peroxidation by measuring malondialdehyde (MDA) rate; also, we studied the response of tomato to this stress by assessing the response of superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), ascorbate peroxidase (APX), glutathione-s-transferase (GST), and glutathione reductase (GR). The effect of the insecticides was observed using four concentrations (25, 50, 75, and 100%) for germinating seeds and only the recommended concentration in agriculture (100%) for growing plants. Our results show an important accumulation of MDA, demonstrating the increase of lipid peroxidation in consequence of the excessive reactive oxygen species (ROS) production due to insecticide treatment. In response to this oxidative stress in tomato seedlings and plants, the activities of antioxidant-enzyme system were generally enhanced. The electrophoretic analysis showed also the apparition of new isoenzymes as the case for CAT and POD.
Topics: Carbamates; Insecticides; Lipid Peroxidation; Solanum lycopersicum; Malondialdehyde; Oxidative Stress; Oxidoreductases; Pyrethrins; Pyrimidines
PubMed: 26178835
DOI: 10.1007/s11356-015-5024-3