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Wei Sheng Yan Jiu = Journal of Hygiene... Mar 2000The acute oral toxicity (LD50) of two pesticides combined from 3 categories of insecticides, i.e. organophosphates(OPs), pyrethroids and carbamates, was evaluated by...
The acute oral toxicity (LD50) of two pesticides combined from 3 categories of insecticides, i.e. organophosphates(OPs), pyrethroids and carbamates, was evaluated by Harris method on equal toxicity doses. The OPs compounds studied included: methylparathion, omethoate, methamidophos, phoxim, dichlorvos, profenofos, isocarbophos and malathion; the pyrethroids: alpha-cypermethrin, deltamethrin, fenvalerate and fenpropathrin; the carbamates: methomyl, isoprocarb and metolcarb. The mixtures of two OPs on the combination of dichlorvos plus omethoate and methamidophos plus profenofos showed additive effects, but methylparathion plus phoxim showed antagonistic effect. Most of the combination of OPs with pyrethroids showed synergistic effects, such as the mixtures of phoxim plus deltamethrin, phoxim plus alpha-cypermethrin, methlyparathion plus alpha-cypermethrin and ioscoarbphos plus fenpropthrin, with the exception of two mixtures showed additive effects: phoxim plus fenvalerate resulting in 1.5 times higher toxicity than expected, while dichlorvos plus deltamethrin resulting in less toxicity than expected. The effects of the mixtures of OPs and carbamates: phoxim plus methomyl and methamidophos plus metolcarb, were all additive, but the mixtures of he methylparathion plus methomyl showed antagonistic effect and malathion plus isoprocarb were synergistic. The biochemical mechanisms of changed toxicity of pesticides mixtures were discussed based on their toxicokinetics and toxicodynamics. It was concluded that the combined effects of insecticide mixtures were additive for OPs plus OPs or plus carbamates in most cased, but synergistic for OPs plus pyrethroids.
Topics: Animals; Drug Synergism; Female; Insecticides; Male; Methomyl; Methyl Parathion; Pyrethrins; Rats; Rats, Wistar
PubMed: 12725074
DOI: No ID Found -
Ecotoxicology and Environmental Safety Feb 2006In this study, five carbamate insecticides were subjected to 96 h acute toxicity tests to examine their effects on three cyanobacteria, Anabaena flos-aquae, Microcystis... (Comparative Study)
Comparative Study
In this study, five carbamate insecticides were subjected to 96 h acute toxicity tests to examine their effects on three cyanobacteria, Anabaena flos-aquae, Microcystis flos-aquae, and Mirocystis aeruginosa, and five green algae, Selenastrum capricornutun, Scenedesmus quadricauda, Scenedesmus obliquus, Chlorella vulgaris, and Chlorella pyrenoidosa. The average acute toxicity of the carbamate insecticides to the cyanobacteria and the green algae was in descending order carbaryl>carbofuran, propoxur, metolcarb > carbosulfan. Wide variations in response to the tested carbamate insecticides occurred among the eight individual species of cyanobacteria and green algae. The sensitivity of various species of algae exposed to carbofuran, propoxur, metolcarb, and carbaryl varied over one order of magnitude, and that of algae exposed to carbosulfan varied over two orders of magnitude. With regard to the diffrential sensitivity of cyanobacteria and green algae, the cyanobacteria were less sensitive than green algae to carbosulfan and propoxur. The pollutants may initiate a shift of algal group structure; especially, a shift from dominance by green algae to dominance by cyanobacteria, and may sustain cyanobacterial blooms at particular times. Therefore, the descending order of the ecosystem risk was carbosulfan > propoxur > carbofuran > carbaryl, metolcarb. There was a strong variance between toxicity and ecosystem risk; i.e., "low toxicity" does not imply "low ecosystem risk."
Topics: Carbamates; Chlorophyta; Cyanobacteria; Insecticides; No-Observed-Adverse-Effect Level
PubMed: 16677910
DOI: 10.1016/j.ecoenv.2004.12.002 -
Inorganic Chemistry Jan 2024A multifunctional single-atom nanozyme, denoted as 3D Ni,N-codoped porous carbon (Ni-NPC), was devised that exhibits remarkable adsorption capabilities and a repertoire...
A multifunctional single-atom nanozyme, denoted as 3D Ni,N-codoped porous carbon (Ni-NPC), was devised that exhibits remarkable adsorption capabilities and a repertoire of enzyme mimetic functions (oxidase- and peroxidase-like). These attributes stem from the distinctive mesoporous thin-shell structure and well-dispersed Ni sites. The efficient adsorption capacity of Ni-NPC was assessed with respect to three carbamate pesticides (CMPs): metolcarb, carbaryl, and isoprocarb. Moreover, a colorimetric detection method for CMP was established based on its robust peroxidase-like catalytic activity and sequential catalytic interactions with acetylcholinesterase. Furthermore, a portable colorimetric sensor based on a hydrogel sphere integrated with a smartphone platform was devised. This sensor enables rapid, on-site, and quantitative assessment of CMP, boasting an extraordinarily low detection limit of 1.5 ng mL. Notably, this sensor was successfully applied to the analysis of CMP levels in lake water and vegetable samples (pakchoi and rape), propelling the progress of real-time detection technologies in food and environment monitoring.
Topics: Smartphone; Acetylcholinesterase; Pesticides; Carbamates; Peroxidase; Peroxidases; Colorimetry
PubMed: 38163760
DOI: 10.1021/acs.inorgchem.3c03642 -
Journal of Chromatography. A Mar 2010A novel ultrasound-assisted surfactant-enhanced emulsification microextraction (UASEME) coupled with high performance liquid chromatography-diode array detection has...
Ultrasound-assisted surfactant-enhanced emulsification microextraction for the determination of carbamate pesticides in water samples by high performance liquid chromatography.
A novel ultrasound-assisted surfactant-enhanced emulsification microextraction (UASEME) coupled with high performance liquid chromatography-diode array detection has been developed for the extraction and determination of six carbamate pesticides (metolcarb, carbofuran, carbaryl, pirimicarb, isoprocarb and diethofencarb) in water samples. In the UASEME technique, Tween 20 was used as emulsifier, and chlorobenzene and chloroform were used as dual extraction solvent without using any organic dispersive solvent that is normally required in the previously described common dispersive liquid-liquid microextraction method. Parameters that affect the extraction efficiency, such as the kind and volume of the extraction solvent, the type and concentration of the surfactant, ultrasound emulsification time and salt addition, were investigated and optimized for the method. Under the optimum conditions, the enrichment factors were in the range between 170 and 246. The limits of detection of the method were 0.1-0.3 ng mL(-1) and the limits of quantification were between 0.3 and 0.9 ng mL(-1), depending on the compounds. The linearity of the method was obtained in the range of 0.3-200 ng mL(-1) for metolcarb, carbaryl, pirimicarb, and diethofencarb, 0.6-200 ng mL(-1) for carbofuran, and 0.9-200 ng mL(-1) for isoprocarb, with the correlation coefficients (r) ranging from 0.9982 to 0.9998. The relative standard deviations varied from 3.2 to 4.8% (n=5). The recoveries of the method for the six carbamates from water samples at spiking levels of 1.0, 10.0, 50.0 and 100.0 ng mL(-1) were ranged from 81.0 to 97.5%. The proposed UASEME technique has demonstrated to be simple, practical and environmentally friendly for the determination of carbamates residues in river, reservoir and well water samples.
Topics: Carbamates; Chemical Fractionation; Chlorobenzenes; Chloroform; Chromatography, High Pressure Liquid; Emulsions; Fresh Water; Linear Models; Pesticides; Polysorbates; Reproducibility of Results; Sensitivity and Specificity; Sodium Chloride; Surface-Active Agents; Temperature; Ultrasonics
PubMed: 20138627
DOI: 10.1016/j.chroma.2010.01.060 -
FEMS Microbiology Letters Jul 2001A carbaryl hydrolase was purified to homogeneity from Arthrobacter sp. strain RC100 by protamine sulfate treatment, ammonium sulfate precipitation, and hydrophobic,...
A carbaryl hydrolase was purified to homogeneity from Arthrobacter sp. strain RC100 by protamine sulfate treatment, ammonium sulfate precipitation, and hydrophobic, anion-exchange, and gel filtration chromatographies. The native enzyme had a molecular mass of 100 kDa and was composed of two identical subunits with molecular masses of 51 kDa. The hydrolase activity was strongly inhibited by DIFP, PMSF, Hg(2+) and paraoxon but not by EDTA. The optimum pH and temperature for the enzyme activity were 9.0 and 50 degrees C, respectively. The enzyme hydrolyzed four N-methylcarbamate insecticides (carbaryl, xylylcarb, metolcarb and XMC), but was not able to hydrolyze fenobucarb, propoxur, and isoprocarb.
Topics: Arthrobacter; Carbaryl; Carboxylic Ester Hydrolases; Edetic Acid; Enzyme Inhibitors; Hydrogen-Ion Concentration; Insecticides; Kinetics; Mercury; Molecular Weight; Paraoxon; Protease Inhibitors; Protein Subunits; Substrate Specificity; Temperature
PubMed: 11445174
DOI: 10.1111/j.1574-6968.2001.tb10739.x -
Talanta Jun 2004A high performance liquid chromatography with fluorescence (HPLC-F) detector was examined to simultaneous determination of airborne carbamates in the workplace of...
A high performance liquid chromatography with fluorescence (HPLC-F) detector was examined to simultaneous determination of airborne carbamates in the workplace of manufactory. The OVS-2 air sampling tube filled with glass fiber filter or quartz fiber and combined filter/XAD-2 were evaluated to collect nine commonly used carbamates (Carbofuran, Isoprocarb, Methomyl, Metolcarb, Thiodicarb, Carbaryl, Oxamyl, Methiocarb, and Prpoxur) from the air of manufactory in high humidity country. After being extracted with acetonitrile from sampling tubes, the carbamates were determined by high performance liquid chromatography with fluorescence detection posterior to on-line derivatization. The collection of carbamates and the recovery of extraction from glass wool fiber in several concentration levels, and from quartz filter were evaluated. The storage stability of carbamates was also tested. Results indicated that the HPLC-fluorescence method offers satisfactory resolution and sensitivity in carbamate analysis. With the glass fiber filter and combined filter/XAD-2, the Carbofuran, Isoprocarb, Methomyl, Metolcarb, and Thiodicarb were stable for a 28-day storage test, Carbaryl and Oxamyl for 14 days, and Methiocarb and Prpoxur for 7 days. All of these pesticides were with detection limit of 3mugm(-3). It is suited for environmental monitoring. The airborne carbamates in different areas of the manufactory were measured.
PubMed: 18969467
DOI: 10.1016/j.talanta.2003.11.031 -
Journal of Chromatography. A Aug 2019A solid phase extraction (SPE) method with a porous organic polymer as adsorbent was established for the extraction of five carbamate pesticides (metolcarb, carbaryl,...
A solid phase extraction (SPE) method with a porous organic polymer as adsorbent was established for the extraction of five carbamate pesticides (metolcarb, carbaryl, isoprocarb, bassa and diethofencarb) from milk, white wine and juice samples prior to high performance liquid chromatography-diode array detection. The main factors affecting the SPE were optimized, including sample volume, sample loading rate, sample solution pH, desorption conditions and cartridge reusability. Under the optimal conditions, a good linearity existed in the range from 1.0 to 320.0 ng mL for milk and white wine samples and from 0.5 to 160.0 ng mL for juice sample with the correlation coefficients between 0.9956 and 0.9998. The method recoveries of the carbamates were 82.0%-110.0%. The limits of detection were 0.12-0.40 ng mL for milk and white wine samples, and 0.06-0.20 ng mL for juice sample. The adsorption mechanism of the adsorbent was investigated by the extraction of different types of organic compounds (carbamates, benzoylurea insecticides, endocrine disrupting chemicals and polycyclic aromatic hydrocarbons) with the adsorbent. The results showed that the existence of the hydrogen-bonding between the adsorbent and the analytes is favorable for the adsorption and strong hydrophobicity seems to have an adverse effect.
Topics: Adsorption; Animals; Beverages; Chromatography, High Pressure Liquid; Food Analysis; Fruit and Vegetable Juices; Hydrophobic and Hydrophilic Interactions; Milk; Pesticides; Polymers; Porosity; Solid Phase Extraction; Wine
PubMed: 31010634
DOI: 10.1016/j.chroma.2019.04.031 -
Journal of Hazardous Materials May 2014A technique for multiplex detection of organophosphorus pesticides and carbamate pesticides has been developed using a suspension array based on silica-hydrogel hybrid...
A technique for multiplex detection of organophosphorus pesticides and carbamate pesticides has been developed using a suspension array based on silica-hydrogel hybrid microbeads (SHHMs). The main advantage of SHHMs, which consist of both silica and hydrogel materials, is that they not only could be distinguished by their characteristic reflection peak originating from the stop-band of the photonic crystal but also have low non-specific adsorption of proteins. Using fluorescent immunoassay, the LODs for fenitrothion, chlorpyrifos-methyl, fenthion, carbaryl and metolcarb were measured to be 0.02ng/mL, 0.012ng/mL, 0.04ng/mL, 0.05ng/mL and 0.1ng/mL, respectively, all of which are much lower than the maximum residue limits, as reported in the European Union pesticides database. All the determination coefficients for these five pesticides were greater than 0.99, demonstrating excellent correlations. The suspension array was specific and had no significant cross-reactivity with other chemicals. The results for the detection of pesticide residues collected from agricultural samples using this method agree well with those from liquid chromatography-tandem mass spectrometry. Our results showed that this simple method is suitable for simultaneous detection of these five pesticides residues in fruits and vegetables.
Topics: Carbamates; Fruit; Hydrogels; Microspheres; Organophosphorus Compounds; Pesticides; Silicon Dioxide; Vegetables
PubMed: 24769809
DOI: 10.1016/j.jhazmat.2014.03.006 -
Ecotoxicology and Environmental Safety Jan 2024Eisenia fetida is recognised as advantageous model species in ecotoxicological and regeneration investigations. The intensive utilization of carbamate pesticides (CARs)...
Eisenia fetida is recognised as advantageous model species in ecotoxicological and regeneration investigations. The intensive utilization of carbamate pesticides (CARs) imposes heavy residue burdens and grave hazards on edaphic environments as well as soil fauna therein. However, precise mechanisms whereby the specific CAR exerted toxic effects on earthworms remain largely elusive, notably from regenerative perspective. Herein, acute responses and regenerative toxicity of two carbamates (metolcarb, MEB and fenoxycarb, FEB) against E. fetida were dissected using biochemical, histological as well as molecular approaches following OECD guidelines at the cellular, tissue and organismal level. The acute toxicity data implied that MEB/FEB were very toxic/medium to extremely toxic, respectively in filter paper contact test and low to medium toxic/low toxic, respectively in artificial soil test. Chronic exposure to MEB and FEB at sublethal concentrations significantly mitigated the soluble protein content, protein abundance while enhanced the protein carbonylation level. Moreover, severely retarded posterior renewal of amputated earthworms was noticed in MEB and FEB treatments relative to the control group, with pronouncedly compromised morphology, dwindling segments and elevated cell apoptosis of blastema tissues, which were mediated by the rising Sox2 and decreasing TCTP levels. Taken together, these findings not only presented baseline toxicity cues for MEB and FEB exposure against earthworms, but also yielded mechanistic insights into regenerative toxicity upon CAR exposure, further contributing to the environmental risk assessment and benchmark formulation of agrochemical pollution in terrestrial ecosystem.
Topics: Animals; Carbamates; Oligochaeta; Ecosystem; Soil Pollutants; Soil
PubMed: 38096595
DOI: 10.1016/j.ecoenv.2023.115824 -
Journal of Separation Science Apr 2013In this paper, a novel graphene (G) grafted silica-coated Fe3O4 nanocomposite was fabricated by the chemical bonding of G onto the surface of silica-coated Fe3 O4...
In this paper, a novel graphene (G) grafted silica-coated Fe3O4 nanocomposite was fabricated by the chemical bonding of G onto the surface of silica-coated Fe3 O4 nanoparticles. Some carbamates (metolcarb, carbaryl, pirimicarb, and diethofencarb) in cucumber and pear samples were enriched by this nanocomposite prior to their determination by HPLC with UV detection. Experimental parameters that may affect the extraction efficiency were investigated. Under the optimum conditions, a linear response was achieved in the concentration range of 0.5-100.0 ng/g for metolcarb, carbaryl, and diethofencarb, and 1.0-100 ng/g for pirimicarb with the correlation coefficients (r) ranging from 0.9956 to 0.9984. The LOD (S/N = 3) of the method were found to be in the range from 0.08 to 0.2 ng/g. The RSDs were in the range from 2.4 to 5.8%. The results indicated that the G grafted silica-coated Fe3 O4 nanocomposite was stable and efficient for magnetic SPE and has a great application potential for the preconcentration of other organic pollutants from real samples.
Topics: Carbamates; Chromatography, High Pressure Liquid; Cucumis sativus; Ferric Compounds; Graphite; Microscopy, Atomic Force; Nanocomposites; Pyrus; Silicon Dioxide
PubMed: 23404952
DOI: 10.1002/jssc.201201036