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Environmental Monitoring and Assessment May 2023In this study, the degradation of two organophosphate pesticides, namely, propetamphos and azamethiphos, in the presence of Ag at different mole ratios was investigated....
In this study, the degradation of two organophosphate pesticides, namely, propetamphos and azamethiphos, in the presence of Ag at different mole ratios was investigated. Moreover, the kinetic and degradation pathways of both chemicals in the range of 0-60 min were explored. Gas chromatography equipped with a thermionic specific detector was used to investigate the pesticide degradation kinetics and mechanism. The results show that the degradation rate of both pesticides follows first-order kinetic. The first-order rate constant and the half-life of reaction were in the range of 0.002-0.143 min, 187-2.1 min, and 0.005-0.164 min and 60-1.8 min, for propetamphos and azamethiphos, respectively, at ambient temperature (25 ºC). Because group containing sulfur atom is a better leaving group than group containing nitrogen, the rate of degradation of azamethiphos is higher than propetamphos. In a higher mole ratio of Ag to pesticides, the degradation rate was increased, and it is possible to predict the rate of degradation of pesticides according to the chemical composition of leaving group.
Topics: Silver; Environmental Monitoring; Pesticides
PubMed: 37249693
DOI: 10.1007/s10661-023-11356-w -
Sensors (Basel, Switzerland) Mar 2022Azamethiphos (AZA) is an insecticide and neurotoxic agent that causes the inhibition of acetylcholinesterase (AChE). AChE is a vital enzyme for neurotransmission because...
Azamethiphos (AZA) is an insecticide and neurotoxic agent that causes the inhibition of acetylcholinesterase (AChE). AChE is a vital enzyme for neurotransmission because it metabolizes acetylcholine neurotransmitter at the synaptic cleft and terminates synaptic transmission. It is worth mentioning that organophosphates and carbamates inhibit AChE. These AChE inhibitors bind to the active site of the enzyme and inactivate it, leading to paralysis and death. Herein, for the first time, we develop a sensitive, low-cost, and rapid electrogenerated chemiluminescence (ECL) system for the detection of AZA. The designed ECL sensor was applied for the highly sensitive detection of AZA with a wide dynamic range (from 0.1 μM to 1000 μM) and low detection limit of 0.07 μM (S/N = 3). The practical utility of the sensor demonstrates high recoveries (96-102%) in real samples of lake water and wastewater.
Topics: 2,2'-Dipyridyl; Acetylcholinesterase; Insecticides; Luminescence; Luminescent Measurements; Organothiophosphates; Ruthenium
PubMed: 35408132
DOI: 10.3390/s22072519 -
Tropical Medicine & International... Dec 2020To investigate what toxicological interactions occur when binary combinations of azamethiphos and botanical monoterpenes (eugenol, menthol or menthyl acetate) are...
OBJECTIVE
To investigate what toxicological interactions occur when binary combinations of azamethiphos and botanical monoterpenes (eugenol, menthol or menthyl acetate) are applied to Triatoma infestans.
METHODS
The toxicity of binary mixtures of azamethiphos and sublethal doses of a monoterpene (eugenol, menthol or menthyl acetate) was evaluated in nymphs of the first stage of T. infestans. Experiments using exposure to filter papers and topical application were carried out. Values of Lethal Concentration 50% (LC50) were calculated in the first case, and values of Lethal Dose 50% (LD50) in the second.
RESULTS
The LC50 of azamethiphos applied on filter paper was 50.3 µg/cm . However, when it was simultaneously applied with a sublethal concentration of monoterpene, its toxicity increased (LC50 with eugenol = 11.20 µg/cm , LC50 with menthyl acetate = 5.30 µg/cm , LC50 with menthol = 7.26 µg/cm ). When applied topically, the LD50 of azamethiphos was 7.85 µg/insect, but its toxicity drastically increased when it was applied together with sublethal doses of menthol (LD50 = 0.00016 µg/insect) or menthyl acetate (LD50 = 0.00051 µg/insect). The simultaneous application with eugenol did not significantly change azamethiphos toxicity (LD50 = 12.79 µg/insect).
CONCLUSIONS
The toxicity of azamethiphos in T. infestans was synergised when it was applied together with eugenol, menthol or menthyl acetate on a filter paper. However, only menthol and menthyl acetate synergysed azamethiphos when mixtures were topically applied. The drastic effects of menthol and menthyl acetate in topical application experiments should be further studied as they could be the basis for developing more efficient triatomicidal products with a lower content of conventional insecticides than those currently used for controlling T. infestans.
Topics: Animals; Chagas Disease; Insect Control; Insect Repellents; Insect Vectors; Lethal Dose 50; Monoterpenes; Nymph; Organothiophosphates; Plant Oils; Triatoma
PubMed: 32945539
DOI: 10.1111/tmi.13488 -
Evaluation of azamethiphos and dimethoate degradation using chlorine dioxide during water treatment.Environmental Science and Pollution... Jul 2020Chlorine dioxide (ClO) degradation of the organophosphorus pesticides azamethiphos (AZA) and dimethoate (DM) (10 mg/L) in deionized water and in Sava River water was...
Chlorine dioxide (ClO) degradation of the organophosphorus pesticides azamethiphos (AZA) and dimethoate (DM) (10 mg/L) in deionized water and in Sava River water was investigated for the first time. Pesticide degradation was studied in terms of ClO level (5 and 10 mg/L), degradation duration (0.5, 1, 2, 3, 6, and 24 h), pH (3.00, 7.00, and 9.00), and under light/dark conditions in deionized water. Degradation was monitored using high-performance liquid chromatography. Gas chromatography coupled with triple quadrupole mass detector was used to identify degradation products of pesticides. Total organic carbon was measured to determine the extent of mineralization after pesticide degradation. Real river water was used under recommended conditions to study the influence of organic matter on pesticide degradation. High degradation efficiency (88-100% for AZA and 85-98% for DM) was achieved in deionized water under various conditions, proving the flexibility of ClO degradation for the examined organophosphorus pesticides. In Sava River water, however, extended treatment duration achieved lower degradation efficiency, so ClO oxidized both the pesticides and dissolved organic matter in parallel. After degradation, AZA produced four identified products (6-chlorooxazolo[4,5-b]pyridin-2(3H)-one; O,O,S-trimethyl phosphorothioate; 6-chloro-3-(hydroxymethyl)oxazolo[4,5-b]pyridin-2(3H)-one; O,O-dimethyl S-hydrogen phosphorothioate) and DM produced three (O,O-dimethyl S-(2-(methylamino)-2-oxoethyl) phosphorothioate; e.g., omethoate; S-(2-(methylamino)-2-oxoethyl) O,O-dihydrogen phosphorothioate; O,O,S-trimethyl phosphorodithioate). Simple pesticide degradation mechanisms were deduced. Daphnia magna toxicity tests showed degradation products were less toxic than parent compounds. These results contribute to our understanding of the multiple influences that organophosphorus pesticides and their degradation products have on environmental ecosystems and to improving pesticide removal processes from water.
Topics: Animals; Chlorine Compounds; Dimethoate; Ecosystem; Organothiophosphates; Oxides; Pesticides; Water Pollutants, Chemical; Water Purification
PubMed: 32399889
DOI: 10.1007/s11356-020-09069-5 -
PloS One 2015Acetylcholinesterase (AChE) is the primary target for organophosphates (OP). Several mutations have been reported in AChE to be associated with the reduced sensitivity...
Acetylcholinesterase (AChE) is the primary target for organophosphates (OP). Several mutations have been reported in AChE to be associated with the reduced sensitivity against OP in various arthropods. However, to the best of our knowledge, no such reports are available for Lepeophtheirus salmonis. Hence, in the present study, we aimed to determine the association of AChE(s) gene(s) with resistance against OP. We screened the AChE genes (L. salmonis ace1a and ace1b) in two salmon lice populations: one sensitive (n=5) and the other resistant (n=5) for azamethiphos, a commonly used OP in salmon farming. The screening led to the identification of a missense mutation Phe362Tyr in L. salmonis ace1a, (corresponding to Phe331 in Torpedo californica AChE) in all the samples of the resistant population. We confirmed the potential role of the mutation, with reduced sensitivity against azamethiphos in L. salmonis, by screening for Phe362Tyr in 2 sensitive and 5 resistant strains. The significantly higher frequency of the mutant allele (362Tyr) in the resistant strains clearly indicated the possible association of Phe362Tyr mutation in L. salmonis ace1a with resistance towards azamethiphos. The 3D modelling, short term survival experiments and enzymatic assays further supported the imperative role of Phe362Tyr in reduced sensitivity of L. salmonis for azamethiphos. Based on all these observations, the present study, for the first time, presents the mechanism of resistance in L. salmonis against azamethiphos. In addition, we developed a rapid diagnostic tool for the high throughput screening of Phe362Tyr mutation using High Resolution Melt analysis.
Topics: Alleles; Animals; Base Sequence; Biological Assay; Codon; Crustacea; Drug Resistance; Female; Genotype; Homozygote; Molecular Sequence Data; Mutation, Missense; Organophosphates; Organothiophosphates; Phenotype; Polymorphism, Genetic; Salmon; Sequence Homology, Nucleic Acid
PubMed: 25893248
DOI: 10.1371/journal.pone.0124220 -
Environmental Pollution (Barking, Essex... Sep 2020Anti-sea lice pesticides, used in the salmonid aquaculture industry, are a growing environmental concern due to their potential to adversely affect non-target...
Anti-sea lice pesticides, used in the salmonid aquaculture industry, are a growing environmental concern due to their potential to adversely affect non-target crustaceans. Azamethiphos and deltamethrin are two bath treatment pesticides used on salmon farms in Norway, however, limited information is available on their impact on European lobster (Homarus gammarus) larvae in the Norwegian marine environment. Here, we firstly report the lethal (LC) and effective (EC) concentrations of azamethiphos and deltamethrin for stage I and stage II larvae, following 1-h exposures. Using a hydrodynamic model, we also modelled the dispersal of both compounds into the marine environment around selected Norwegian farms and mapped the potential impact zones (areas that experience LC and EC concentrations) around each farm. Our data shows that azamethiphos and deltamethrin are acutely toxic to both larval stages, with LC and EC values below the recommended treatment concentrations. We also show that the azamethiphos impact zones around farms were relatively small (mean area of 0.04-0.2 km), however deltamethrin impact zones covered much larger areas (mean area of 21.1-39.0 km). These findings suggest that deltamethrin poses a significant risk to European lobster in the Norwegian marine environment while the impact of azamethiphos may be less severe.
Topics: Animals; Aquaculture; Copepoda; Fish Diseases; Larva; Nephropidae; Nitriles; Norway; Organothiophosphates; Pesticides; Phthiraptera; Pyrethrins
PubMed: 32388310
DOI: 10.1016/j.envpol.2020.114725 -
Bulletin of Environmental Contamination... Mar 2001
Topics: Alkylation; Insecticides; Organothiophosphates; Structure-Activity Relationship
PubMed: 11178640
DOI: 10.1007/s001280002 -
Food Chemistry Nov 2021A magnetic mesoporous molecularly imprinted polymers was synthesized on the surface of magnetic nanoparticles silanized with 3-(trimethoxysilyl) propyl methacrylate to...
A magnetic mesoporous molecularly imprinted polymers was synthesized on the surface of magnetic nanoparticles silanized with 3-(trimethoxysilyl) propyl methacrylate to introduce reactive methacrylate groups. Subsequently, methacrylic acid monomers were grafted onto the surface of this adsorbent functionalized via polymerization by precipitation. Magnetic mesoporous molecularly imprinted polymer was properly characterized by different techniques and applied as adsorbent in magnetic solid phase extraction for selective determination of two organophosphorus pesticides, azamethiphos and chlorpyrifos, in mineral water and grape samples. After sample preparation optimization, recoveries of 99.56% and 98.86% were obtained for azamethiphos and chlorpyrifos, respectively. The magnetic solid phase extraction coupled to HPLC-UV presented limit of quantification of 5 ng mL, linearity ranged of 5 to 1000 ng mL, in addition to adequate accuracy, precision and robustness. The pesticides showed stability in the matrix and were satisfactorily quantified in real mineral water and grape samples.
Topics: Chlorpyrifos; Chromatography, High Pressure Liquid; Magnetics; Mineral Waters; Molecular Imprinting; Molecularly Imprinted Polymers; Organothiophosphates; Pesticides; Porosity; Solid Phase Extraction; Vitis
PubMed: 34029898
DOI: 10.1016/j.foodchem.2021.130116 -
Marine Environmental Research Jan 2023The pesticide azamethiphos used by the salmon industry to treat sea lice, is applied as a bath and subsequently discharged into the sea. The effects of azamethiphos...
The interactive effect of anti-sea lice pesticide azamethiphos and temperature on the physiological performance of the filter-feeding bivalve Ostrea chilensis: A non-target species.
The pesticide azamethiphos used by the salmon industry to treat sea lice, is applied as a bath and subsequently discharged into the sea. The effects of azamethiphos concentration (0, 15 and 100 μg L) on the physiology of the Chilean oyster (Ostrea chilensis) at two temperatures (12 and 15 °C) was examined. In all azamethiphos treatments, oysters kept at 15 °C had clearance rates (CR) higher than oysters kept at 12 °C. The oxygen consumption rate (OCR) increased at higher temperatures, except with 100 μg L of azamethiphos, where no changes were observed. Sixty days after the exposure, survival rates of 91 and 79% (15 and 100 μg L, respectively), were observed compared to the controls, a situation independent of the experimental temperature. The interaction between temperature and pesticide has detrimental effects on the physiological performance and survival of O. chilensis, and these effects should also be assessed for other non-target species.
Topics: Animals; Pesticides; Temperature; Ostrea; Organothiophosphates
PubMed: 36481714
DOI: 10.1016/j.marenvres.2022.105837 -
Pharmacological Research Feb 2004The safety of azamethiphos (AZA), an organophosphorous insecticide and the active ingredient of Salmosan, was evaluated in the European eel, seabass and rainbow trout....
The safety of azamethiphos (AZA), an organophosphorous insecticide and the active ingredient of Salmosan, was evaluated in the European eel, seabass and rainbow trout. Fish were bathed in 0.1 ppm AZA for a period of 60, 120 or 240 min. After termination of each treatment fish were transferred to clean aquaria and randomly sampled over 21 days. Compared to controls, brain acetylcholinesterase (AChE) was inhibited up to 44, 56 and 62% in eels, seabass and trout, respectively, with the inhibition being significant for up to 4 days in eels and seabass and 7 days in trout. As result of the AChE depression, fish displayed motor hyperactivity and erratic jumping at the onset of treatment. Mortality was observed only in trout following exposure for 240 min. A variable correlation observed among species between the level of exposure, the reduced activity of brain AChE and the signs of toxicity suggest that brain AChE should be considered as an indicator of exposure rather than as an index of toxicity of AZA. The present data indicate that at the therapeutic dosage of 0.1 ppm AZA for 1h can be safely used in eels, seabass and trout. The extended treatment times up to 240 min were equally safe for eels and seabass but not for trout.
Topics: Acetylcholinesterase; Animals; Bass; Brain; Cholinesterase Inhibitors; Eels; Fishes; Hyperkinesis; Insecticides; Oncorhynchus mykiss; Organothiophosphates; Risk Assessment; Time Factors; Toxicity Tests, Acute
PubMed: 14643697
DOI: 10.1016/j.phrs.2003.08.002