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The Journal of Toxicological Sciences Dec 2015Given the rapid onset of symptoms from intoxication by organophosphate (OP) compounds, a quick-acting, efficacious therapeutic regimen is needed. A primary component of...
Given the rapid onset of symptoms from intoxication by organophosphate (OP) compounds, a quick-acting, efficacious therapeutic regimen is needed. A primary component of anti-OP therapy is an oxime reactivator to rescue OP-inhibited acetylcholinesterases. Male guinea pigs, clipped of hair, received neat applications of either VR, VX, parathion, or phorate oxon (PHO) at the 85(th) percentile lethal dose, and, beginning with presentation of toxicosis, received the human equivalent dose therapy by intramuscular injection with two additional follow-on treatments at 3-hr intervals. Each therapy consisted of atropine free base at 0.4 mg/kg followed by one of eight candidate oximes. Lethality rates were obtained at 24 hr after VR, VX and PHO challenges, and at 48 hr after challenge with parathion. Lethality rates among symptomatic, oxime-treated groups were compared with that of positive control (OP-challenged and atropine-only treated) guinea pigs composited across the test days. Significant (p ≤ 0.05) protective therapy was afforded by 1,1-methylene bis(4(hydroxyimino- methyl)pyridinium) dimethanesulfonate (MMB4 DMS) against challenges of VR (p ≤ 0.001) and VX (p ≤ 0.05). Lethal effects of VX were also significantly (p ≤ 0.05) mitigated by treatments with oxo-[[1-[[4-(oxoazaniumylmethylidene)pyridin-1-yl]methoxymethyl]pyridin-4-ylidene]methyl]azanium dichloride (obidoxime Cl2) and 1-(((4-(aminocarbonyl) pyridinio)methoxy)methyl)-2,4-bis((hydroxyimino)methyl)pyridinium dimethanesulfonate (HLö-7 DMS). Against parathion, significant protective therapy was afforded by obidoxime dichloride (p ≤ 0.001) and 1,1'-propane-1,3-diylbis{4-[(E)-(hydroxyimino)methyl]pyridinium} dibromide (TMB-4, p ≤ 0.01). None of the oximes evaluated was therapeutically effective against PHO. Across the spectrum of OP chemicals tested, the oximes that offered the highest level of therapy were MMB4 DMS and obidoxime dichloride.
Topics: Animals; Guinea Pigs; Humans; Male; Nerve Agents; Organophosphate Poisoning; Oximes; Pesticides
PubMed: 26558457
DOI: 10.2131/jts.40.759 -
Analytical and Bioanalytical Chemistry Jan 2016The present study reports a highly simple and rapid method for the detection of a widely used and extremely toxic organophosphorus pesticide, phorate. The detection...
The present study reports a highly simple and rapid method for the detection of a widely used and extremely toxic organophosphorus pesticide, phorate. The detection employs a pesticide-specific aptamer as the recognition element and gold nanoparticles as the optical sensors. The aptamer, owing to its random coil structure, provides stability to the gold nanoparticles upon linking, thereby keeping the nanoparticles well dispersed. However, on the addition of the target pesticide, the aptamer acquires a rigid conformation resulting in the aggregation of the gold nanoparticles. Consequently, the color of the solution changes from red to blue and is easily observable with the naked eye. The proposed method was linear in the concentration range of 0.01 nM to 1.3 μm with the limit of detection as low as 0.01 nM. Moreover, the proposed assay selectively recognized phorate in the presence of other interfering substances and, thus, can be applied to real samples for the rapid and efficient screening of phorate.
Topics: Aptamers, Nucleotide; Colorimetry; Gold; Pesticides; Phorate
PubMed: 26462920
DOI: 10.1007/s00216-015-9085-4 -
Analytica Chimica Acta Sep 2015A nanomaterials-based novel molecular beacon has attracted growing attentions in fluorescent assays as many nanomaterials possess excellent quenching efficiency. In this...
A nanomaterials-based novel molecular beacon has attracted growing attentions in fluorescent assays as many nanomaterials possess excellent quenching efficiency. In this work, a gold-based nanobeacon probe was established to detect organophosphorus pesticides for the first time. The constructed gold-based nanobeacon acted as a signal indicator and could display the decreasing of the intensity in the presence of targets, which competitively bound to single strand DNA. To achieve a high sensitive probe, some parameters including solution pH, temperature and reaction time were investigated and optimized. The gold-based nanobeacon probe assay was proved to be rapid and sensitive to achieve a detection limit of 0.035 μM for isocarbophos, 0.134 μM for profenofos, 0.384 μM for phorate and 2.35 μM for omethoate, respectively. The prepared nanobeacon effectively reduced the background and improved the detection sensitivity and selectivity. The probe is stable, easy to operate and does not need sophisticated instruments. These features makes the probe feasible for screening trace organophosphorus pesticides in real samples.
Topics: Aptamers, Nucleotide; DNA, Single-Stranded; Fluorescence Resonance Energy Transfer; Fluorescent Dyes; Gold; Limit of Detection; Metal Nanoparticles; Organophosphorus Compounds; Pesticides
PubMed: 26388389
DOI: 10.1016/j.aca.2015.08.012 -
Se Pu = Chinese Journal of... Apr 2015A matrix solid-phase dispersion-ultra performance liquid chromatography-tandem mass spectrometry (MSPD-UPLC-MS/MS) method was established for the simultaneous deter-...
A matrix solid-phase dispersion-ultra performance liquid chromatography-tandem mass spectrometry (MSPD-UPLC-MS/MS) method was established for the simultaneous deter- mination of carbendiazin, omethoate, carbofuran, aldicarb, chlorpyrifos, methamidophos, phorate, parathion and parathion-methyl residues in vegetables. The samples were extracted by acetonitrile and separated with salting out method. And then the supernatants were purified by matrix solid-phase dispersion for the UPLC-MS/MS analysis. The separation was performed on a Waters Acquity UPLC system with a BEH C18 column with the gradient elution of acetonitrile and water containing 0. 1% (v/v) acetic acid. The nine pesticides were determined in the modes of electrospray positive ionization (ESI+) and multiple reaction monitoring (MRM). The ana- lytes were quantified by matrix matched standard solution curves. The limits of detection (S/N ≥ 3) were 0.8-4.0 µg/kg. The average recoveries were 72.8%-117.4%. The detection rates were 42.0% for chlorpyrifos, 14.0% for carbendiazin and 1.5% for dimethoate, and the exces- sive rate of chlorpyrifos was 8.0% in the determination of 50 real samples; the other pesticides were not detected. The method is simple, accurate and highly reproducible. This method is suit- able for the quality control of pesticide residues in risk monitoring of the safety of the foods.
Topics: Chromatography, High Pressure Liquid; Food Contamination; Pesticide Residues; Tandem Mass Spectrometry; Vegetables
PubMed: 26292412
DOI: 10.3724/sp.j.1123.2014.12016 -
Journal of Chromatographic Science 2015In this work, a rapid, environment friendly and sensitive method was established for the extraction and analysis of five organophosphorus pesticides (OPPs)...
Modified QuEChERS in combination with dispersive liquid-liquid microextraction based on solidification of the floating organic droplet method for the determination of organophosphorus pesticides in milk samples.
In this work, a rapid, environment friendly and sensitive method was established for the extraction and analysis of five organophosphorus pesticides (OPPs) (chlorpyrifos, chlorpyrifos-methyl, isocarbophos, malathion and phorate) in milk samples by means of gas chromatography-flame photometric detection. The pesticides were first extracted with acetonitrile from milk samples by using the modified "quick, easy, cheap, effective, rugged, and safe" (QuEChERS) method. No other clean-up was required after extraction. Then the above-mentioned acetonitrile extract was concentrated by using the dispersive liquid-liquid microextraction combined with solidification of floating organic droplets technique. Several factors that could influence the extraction efficiency, such as type of extraction solvent, disperser solvent, volume of extraction and disperser solvent, salt effect, sample pH, and extraction time, were investigated and optimized. As a result, 15 µL of 1-dodecanol were used as the extractant because of its lower toxicity, 300 µL methanol was chosen as dispersant and the extraction time was set to 1 min. Under the optimized conditions, good linearity was exhibited from 0.01 to 1.0 mg/L with the correlation coefficients higher than 0.9968. The limits of detection of the five OPPs were ranged in 0.1-0.3 μg/L, and the limits of quantification were at the range of 0.3-1.0 μg/L. Moreover, the recoveries of the target analytes from milk samples at spiking levels of 0.01, 0.05 and 0.1 mg/L were between 80.5 and 106.5% with the relative standard deviations varied from 3.6 to 6.3%. This method has been successfully applied to detect OPPs in real milk samples.
Topics: Animals; Limit of Detection; Liquid Phase Microextraction; Milk; Organophosphorus Compounds; Pesticides
PubMed: 26270080
DOI: 10.1093/chromsci/bmv089 -
Xenobiotica; the Fate of Foreign... 20161. It has been demonstrated that the ingestion of foods containing quercetin protects against the toxicity of single pesticides. The aim of this study is to make a...
1. It has been demonstrated that the ingestion of foods containing quercetin protects against the toxicity of single pesticides. The aim of this study is to make a comprehensive elaboration about the protective effect of quercetin against multi-organophosphorous pesticides induced nephrotoxicity by measuring indices in rat kidney, urine and serum. Rats were divided into six groups (n = 10/group): control, two different doses of quercetin, pesticide mixture (PM), and different doses of quercetin plus PM-treated groups. 2. The following parameters were significantly changed in PM-treated groups compared with the control (p < 0.01). In kidney, malondialdehyde level raised; catalase, superoxide dismutase activities and glutathione levels were decreased. Comet assay of nephrocytes showed that the proportion of DNA in the tail and tail length increased. In urine, β2-microglobulin, retinol-conjugated protein levels and N-acetyl-β-D-glucosaminidase activity showed increasing response; meanwhile uric acid level was decreased. In serum, creatinine and urea nitrogen levels were increased. However, the anomaly changes of indexes mentioned above in PM-treated group were alleviated when simultaneously administrated with 50 mg/kg body weight/day quercetin (p < 0.05). 3. From the present findings, it can be evaluated that quercetin may protect against adverse effects resulted from multi-organophosphorous pesticides with significant high levels of uptake in man provided.
Topics: Acetylglucosaminidase; Animals; Antioxidants; Catalase; Comet Assay; Creatinine; DNA Damage; Dose-Response Relationship, Drug; Glutathione; Kidney; Kidney Diseases; Lipid Peroxidation; Male; Malondialdehyde; Organophosphorus Compounds; Oxidative Stress; Pesticides; Quercetin; Rats; Rats, Wistar; Sensitivity and Specificity; Superoxide Dismutase; Urea; beta 2-Microglobulin
PubMed: 26226520
DOI: 10.3109/00498254.2015.1070443 -
Bulletin of Environmental Contamination... Oct 2015A simple, rapid and sensitive spectrofluorimetric method was developed for the determination of di-syston, ethion and phorate in environmental water samples. The...
A simple, rapid and sensitive spectrofluorimetric method was developed for the determination of di-syston, ethion and phorate in environmental water samples. The procedure is based on the oxidation of these pesticides with cerium (IV) to produce cerium (III), and its fluorescence was monitored at 368 ± 3 nm after excitation at 257 ± 3 nm. The variables effecting oxidation of each pesticide were studied and optimized. Under the experimental conditions used, the calibration graphs were linear over the range 0.2-15, 0.1-13, 0.1-13 ng mL(-1) for di-syston, ethion and phorate, respectively. The limit of detection and quantification were in the range 0.034-0.096 and 0.112-0.316 ng mL(-1), respectively. Intra- and inter-day assay precisions, expressed as the relative standard deviation (RSD), were lower than 5.2 % and 6.7 %, respectively. Good recoveries in the range 86 %-108 % were obtained for spiked water samples. The proposed method was applied to the determination of studied pesticides in environmental water samples.
Topics: Disulfoton; Environmental Monitoring; Insecticides; Organothiophosphorus Compounds; Phorate; Spectrometry, Fluorescence; Water Quality
PubMed: 26210825
DOI: 10.1007/s00128-015-1612-7 -
Bulletin of Environmental Contamination... Nov 2015Phorate, an organophosphorus insecticide, has been found effective for the control of various insect pests. However, it is an extremely hazardous insecticide and causes...
Phorate, an organophosphorus insecticide, has been found effective for the control of various insect pests. However, it is an extremely hazardous insecticide and causes a potential threat to ecosystem. Bioremediation is a promising approach to degrade the pesticide from the soil. The screening of soil from sugarcane fields resulted in identification of Brevibacterium frigoritolerans, a microorganism with potential for phorate bioremediation was determined. B. frigoritolerans strain Imbl 2.1 resulted in the active metabolization of phorate by between 89.81% and 92.32% from soils amended with phorate at different levels (100, 200, 300 mg kg(-1) soil). But in case of control soil, 33.76%-40.92% degradation were observed. Among metabolites, sulfone was found as the main metabolite followed by sulfoxide. Total phorate residues were not found to follow the first order kinetics. This demonstrated that B. frigoritolerans has potential for bioremediation of phorate both in liquid cultures and agricultural soils.
Topics: Agriculture; Bacillus; Biodegradation, Environmental; Brevibacterium; Insecticides; Kinetics; Phorate; Soil; Soil Microbiology; Soil Pollutants
PubMed: 26205232
DOI: 10.1007/s00128-015-1617-2 -
Ecotoxicology and Environmental Safety Dec 2015Use of phorate as a broad spectrum pesticide in agricultural crops is finding disfavor due to persistence of both the principal compound as well as its toxic residues in...
Use of phorate as a broad spectrum pesticide in agricultural crops is finding disfavor due to persistence of both the principal compound as well as its toxic residues in soil. Three phorate utilizing bacterial species (Pseudomonas sp. strain Imbl 4.3, Pseudomonas sp. strain Imbl 5.1, Pseudomonas sp. strain Imbl 5.2) were isolated from field soils. Comparative phorate degradation analysis of these species in liquid cultures identified Pseudomonas sp. strain Imbl 5.1 to cause complete metabolization of phorate during seven days as compared to the other two species in 13 days. In soils amended with phorate at different levels (100, 200, 300 mg kg(-1) soil), Pseudomonas sp. strain Imbl 5.1 resulted in active metabolization of phorate by between 94.66% and 95.62% establishing the same to be a potent bacterium for significantly relieving soil from phorate residues. Metabolization of phorate to these phorate residues did not follow the first order kinetics. This study proves that Pseudomonas sp. strain Imbl 5.1 has huge potential for active bioremediation of phorate both in liquid cultures and agricultural soils.
Topics: Agriculture; Biodegradation, Environmental; Phorate; Pseudomonas; Soil; Soil Microbiology; Soil Pollutants
PubMed: 26186726
DOI: 10.1016/j.ecoenv.2015.07.007 -
Analytical Chemistry Jun 2015Detection of mercapto-containing pesticides plays a crucial role in food and water safety. A new Re(I)-NCS-Pt(II) complex,...
Detection of mercapto-containing pesticides plays a crucial role in food and water safety. A new Re(I)-NCS-Pt(II) complex, [Re(4,4'-di-tert-butyl-2,2'-bipyridine)(CO)3(NCS)]-[Pt(DMSO)(Cl)2] (1), was synthesized and characterized. The synthetic procedure, characterization results, and photophysical data for 1 are reported in this paper. Solvated complex 1 demonstrated luminescent chemodosimetric selectivity for phorate, demeton, and aldicarb (three common mercapto-containing pesticides) with method detection limits (MDLs) of 1.00, 2.87, and 2.08 ppm, respectively. The binding constants (log K) of 1 toward them were in the 3.24-3.44 range. The analyte selectivity of the complex was found to be dependent on the bridging linkage (C≡N and N═C═S) between the Re(I) and Pt(II) centers. The solid-supported dosimetric device 1 was fabricated by blending complex 1 with Al2O3 and poly(vinyl chloride) (PVC) powder. The MDLs of the device toward the mercapto-containing pesticides were 0.48-0.60 ppm. The device was applicable to pesticides in real water bodies such as taps, rivers, lakes, and underground water bodies with excellent recoveries and relative standard deviations of 76.2-108.0% and 2.9-6.7%, respectively. Its spectrofluorimetric changes could be analyzed by naked eye within 20 min with a linear luminometric response toward increases in the phorate concentration (0-8.0 ppm) with R = 0.999.
PubMed: 26039794
DOI: 10.1021/acs.analchem.5b00684