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Carbamate pesticide induced toxic epidermal necrolysis  

Directory of Open Access Journals (Sweden)

Full Text Available A 36-year-old male alleged to have consumed carbamate pesticide liquid (Baygon@ developed toxic epidermal necrolysis (TEN within twenty-four hours of intake. Though drugs have been commonly incriminated as offending agents for TEN, carbamate pesticide was found to be the causative agent in our case.

Rajendran N

2001-09-01

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Carbamate pesticide induced toxic epidermal necrolysis  

OpenAIRE

A 36-year-old male alleged to have consumed carbamate pesticide liquid (Baygon@) developed toxic epidermal necrolysis (TEN) within twenty-four hours of intake. Though drugs have been commonly incriminated as offending agents for TEN, carbamate pesticide was found to be the causative agent in our case.

Rajendran N.; Chitfambalam P; Jayaraman A.

2001-01-01

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Analysis of Carbamate Pesticides: Validation of Semi-Volatile Analysis by HPLC-MS/MS by EPA Method MS666  

Energy Technology Data Exchange (ETDEWEB)

The Environmental Protection Agency's (EPA) Region 5 Chicago Regional Laboratory (CRL) developed a method for analysis of aldicarb, bromadiolone, carbofuran, oxamyl, and methomyl in water by high performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS), titled Method EPA MS666. This draft standard operating procedure (SOP) was distributed to multiple EPA laboratories and to Lawrence Livermore National Laboratory, which was tasked to serve as a reference laboratory for EPA's Environmental Reference Laboratory Network (ERLN) and to develop and validate analytical procedures. The primary objective of this study was to validate and verify the analytical procedures described in MS666 for analysis of carbamate pesticides in aqueous samples. The gathered data from this validation study will be used to: (1) demonstrate analytical method performance; (2) generate quality control acceptance criteria; and (3) revise the SOP to provide a validated method that would be available for use during a homeland security event. The data contained in this report will be compiled, by EPA CRL, with data generated by other EPA Regional laboratories so that performance metrics of Method EPA MS666 can be determined.

Owens, J; Koester, C

2008-05-14

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CUMULATIVE EFFECTS OF ORGANOPHOSPHORUS OR CARBAMATE PESTICIDES.  

Science.gov (United States)

This book chapter strives to summarize the body of literature exploring the toxic interaction of organophosphorus and carbamate pesticides in mixtures. This review represents one of the only reviews of the subject that has been published within the last 20 years. Specifically, th...

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Stimulation of Methanogenesis by Aldicarb and Several Other N-Methyl Carbamate Pesticides †  

OpenAIRE

Aldicarb and several other N-methyl carbamate pesticides stimulated methane production in anaerobic salt marsh soils and organic-rich aquifer soils. Stimulation was biological and linearly related to the amount of carbamate added. Of the four carbamates studied, methomyl gave the greatest stimulation followed by carbaryl, aldicarb, and baygon. The percent conversions [(moles of CH4 in excess of control/mole of carbamate added) × 100] for methomyl, carbaryl, aldicarb, and baygon were 88, 57, ...

Kiene, Ronald P.; Capone, Douglas G.

1986-01-01

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DOSE-RESPONSE MODELING FOR THE ASSESSMENT OF CUMULATIVE RISK DUE TO EXPOSURE TO N-METHYL CARBAMATE PESTICIDES  

Science.gov (United States)

The US EPAs N-Methyl Carbamate Cumulative Risk Assessment (NMCRA) assesses the effect on acetylcholine esterase (AChE) activity of exposure to 10 N-methyl carbamate (NMC) pesticides through dietary, drinking water, and residential exposures....

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Induction of tibial dyschondroplasia by carbamate and thiocarbamate pesticides.  

Science.gov (United States)

Tibial dyschondroplasia (TD) is a major poultry leg problem, the natural etiology of which is unknown. Certain dithiocarbamate pesticides such as tetramethyl thiuram disulfide (thiram) have been shown to induce the disease in chickens. Because many different carbamate and thiocarbamate chemicals are used in a number of agricultural, industrial, and household applications, the objective of this study was to determine whether all chemicals of these categories induce TD and whether there is a concentration-dependent relationship between the ingestion of these chemicals and the incidences and the severity of the disease. Week-old broiler chicks were fed diets containing thiram or other assorted carbamate and thiocarbamate pesticides mixed in feed for 24-48 hr between ages 8 and 10 days. The birds were killed on day 15 and the proximal tibial and tarsometatarsal growth plates were evaluated for the presence and severity of TD lesions. TD was distinguished by broadening of growth plates; upon histologic exam chondrocytes appeared to be shrunken and dead. When compared by including equimolar concentrations of these chemicals in the feed, the dithiocarbamates with more than two sulfide groups, such as disulfiram, ferbam, thiram, and ziram were potent inducers of TD, whereas those with two sulfides to no sulfide group appeared ineffective at inducing TD. Both thiram and ferbam also reduced the bird's body weights. Thiram increased the incidence and the severity of the disease, denoted by TD index, in a dose-dependent manner. These results suggest that inadvertent contamination of feed or litter with some of these or similar chemicals may cause leg problems in poultry. PMID:17626489

Rath, N C; Huff, W E; Huff, G R; Kannan, L

2007-06-01

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Cumulative risk assessment of the intake of organophosphorus and carbamate pesticides in the Danish diet  

DEFF Research Database (Denmark)

The aim of the study is to evaluate the potential cumulative effects of organophosphorus and carbamate pesticides that act through a common mechanism of toxicity, and to assess the long- and short-term risks for the Danish population. The intake estimates are based on dietary intake data collected in the Danish nation-wide food consumption survey in 1995. The pesticide data are based on the Danish pesticide residue-monitoring programme from 1996-2001. The amount of 35 organophosphorus pesticides and carbamates were included in the cumulative risk assessment. Processing factors, such as reduction of pesticide levels by rinsing and peeling, were applied in the exposure assessment. The "Toxicity Equivalence Factor" (TEF) approach was used to normalise the toxicity of the different organophosphorus and carbamate pesticides. Cumulative chronic exposure of organophosphorus and carbamates pesticides via fruit, vegetables and cereals is for adults 0.8-2% of the Acceptable Daily Intake (ADI) in chlorpyrifos equivalents, and 0.03-11% of the ADI in methamidophos equivalents; and for children 2-5% of the ADI in the chlorpyrifos equivalents, and 0.07-27% of the ADI in methamidophos equivalents. Neither Acute Reference Dose (ARfD) nor ADI was exceeded for any of the compounds studied. The results indicate that the Danish population is neither exposed to any cumulative chronic risk, nor at risk of acute exposure, from consumption of organophosphorus and carbamate pesticides from fruit, vegetables and cereals.

Jensen, A. F.; Petersen, Annette

2003-01-01

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Organophosphate and Carbamate Pesticide Residues in Beans from Markets in Lagos State, Nigeria  

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Full Text Available Foods treated with pesticides for protection against destructive pests often contain residues of these chemicals. The levels of pesticide residues in food are often determined as a means of assessing appropriate use as well as the level of human exposure to these chemicals and hence their potential human health hazards. The aim of this study was to determine the concentration of organophosphate and carbamate pesticides in beans samples collected from markets in Lagos State and compare these values with established safety values. Beans (Phaseolus vulgaris L. samples purchased from different markets in Lagos State were analyzed for residues of organophosphate and carbamate pesticides. Analysis was done using gas chromatograph with mass spectrometric detector (GC-MS after careful extraction and cleanup. It was found that all the beans samples contained residues of one or more organophosphate or carbamate pesticides. Mean concentrations ranged from 19.4 to 455.9 ?g/kg. Maximum residue limits (MRL of the various pesticides (except for parathion were exceeded in up to 10% of samples. The estimated total diet intake (ETDI for dichlorvos exceeded its maximum permissible intake (MPI by 131%. Organophosphate and carbamate pesticide residues are present in beans sold in Lagos markets and maximum residue limits for most of the pesticides are exceeded. There is therefore a need for more stringent monitoring of importation and use of these pesticides in agriculture and food storage in Nigeria.

Ogah C.O

2011-03-01

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Application of brain cholinesterase reactivation to differentiate between organophosphorus and carbamate pesticide exposure in wild birds  

Science.gov (United States)

Brain cholinesterase activity was measured to evaluate pesticide exposure in wild birds. Thermal reactivation of brain cholinesterase was used to differentiate between carbamate and organophosphorus pesticide exposure. Brain cholinesterase activity was compared with gas chromatography and mass spectrometry of stomach contents. Pesticides were identified and confirmed in 86 of 102 incidents of mortality from 29 states within the USA from 1986 through 1991. Thermal reactivation of cholinesterase activity was used to correctly predict carbamates in 22 incidents and organophosphates in 59 incidents. Agreement (P cholinesterase activities and GC/MS results was significant.

Smith, M.R.; Thomas, N.J.; Hulse, C.

1995-01-01

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Acute poisoning with anticholinesterase carbamate pesticides: methomyl-lannate(®)  

Science.gov (United States)

The methomyl is increasingly involved in suicidal and autolytic attempts. Intoxication with carbamate (CM) compounds is still a frequent cause for admission in the Emergency department of the medical assistance center (MAC) in Tunis, Tunisia. The aim of this study was to describe the demographics, clinical features and hospital course of patients presenting with CM intoxication to the ED of MAC in Tunis, Tunisia. This was a retrospective study about 52 cases of acute poisoning by methomyl, compiled in the MAC from 1st January, 2009 to December 31, 2012. Intoxications were all oral, mostly intentional (33 cases: 65%) and in young patients (29 years old). Females outnumbered males by almost 2:1. The most frequent symptom was hypotension (41 cases: 80%), followed by miosis (39 cases: 75%), rhabdomyolysis (29 cases: 55%), vomiting (18 cases: 43%), bronchorrhea (14 cases: 27%), diarrhea (11 cases: 21%) and fasciculations (8 cases: 17%). Treatments included gastric lavage in 16 patients (32%), assisted ventilation in 8 cases (17%) and atropine in 44 patients (85%). Seven patients died during hospitalization. Pesticide poisoning is a significant public health problem and some preventive measures must be strictly enforced to limit this kind of intoxication. PMID:25486668

Chaouali, Nadia; Amira, Dorra; Zitouni, Eya; Gana, Ines; Nouioui, Anouer; Khelifi, Fathia; Belwaer, Ines; Masri, Wafa; Ghorbal, Hayet; Hedhili, Abderazzek

2014-12-01

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Organophosphate and Carbamate Pesticide Residues in Beans from Markets in Lagos State, Nigeria  

OpenAIRE

Foods treated with pesticides for protection against destructive pests often contain residues of these chemicals. The levels of pesticide residues in food are often determined as a means of assessing appropriate use as well as the level of human exposure to these chemicals and hence their potential human health hazards. The aim of this study was to determine the concentration of organophosphate and carbamate pesticides in beans samples collected from markets in Lagos State and compare these v...

Ogah C.O; Coker H.B; Adepoju-Bello A.A

2011-01-01

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Selective effects of carbamate pesticides on rat neuronal nicotinic acetylcholine receptors and rat brain acetylcholinesterase  

International Nuclear Information System (INIS)

Effects of commonly used carbamate pesticides on rat neuronal nicotinic acetylcholine receptors expressed in Xenopus laevis oocytes have been investigated using the two-electrode voltage clamp technique. The potencies of these effects have been compared to the potencies of the carbamates to inhibit rat brain acetylcholinesterase. The potency order of six carbamates to inhibit ?4?4 nicotinic receptors is fenoxycarb > EPTC > carbaryl, bendiocarb > propoxur > aldicarb with IC50 values ranging from 3 ?M for fenoxycarb to 165 ?M for propoxur and >1 mM for aldicarb. Conversely, the potency order of these carbamates to inhibit rat brain acetylcholinesterase is bendiocarb > propoxur, aldicarb > carbaryl >> EPTC, fenoxycarb with IC50 values ranging from 1 ?M for bendiocarb to 17 ?M for carbaryl and >>1 mM for EPTC and fenoxycarb. The ?4?2, ?3?4, and ?3?2 nicotinic acetylcholine receptors are inhibited by fenoxycarb, EPTC, and carbaryl with potency orders similar to that for ?4?4 receptors. Comparing the potencies of inhibition of the distinct subtypes of nicotinic acetylcholine receptors shows that the ?3?2 receptor is less sensitive to inhibition by fenoxycarb and EPTC. The potency of inhibition depends on the carbamate as well as on a combination of ? and ? subunit properties. It is concluded that carbamate pesticides affect different subtypes of neuronal nicotinic receptors independently of acetylcholinesterase inhibition. This implicates that neuronal nicicates that neuronal nicotinic receptors are additional targets for some carbamate pesticides and that these receptors may contribute to carbamate pesticide toxicology, especially after long-term exposure

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DETERMINATION OF CARBAMATE, UREA, AND THIOUREA PESTICIDES AND HERBICIDES IN WATER  

Science.gov (United States)

Microbe liquid chromatography and positive ion electrospray mass spectrometry are applied to the determination of 16 carbamate, urea, and thiourea pesticides and herbicides in water. The electrospray mass spectra of the analytes were measured and are discussed and mobile phase m...

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Presence of anticholinergic pesticide (organophosphate and carbamate in fruits and vegetable in Cabo Frio city, RJ  

Directory of Open Access Journals (Sweden)

Full Text Available The study used acetylcholinesterase enzyme inhibition to detect organophosphate and carbamate pesticides in fruits and vegetable consumed in the City of Cabo Frio. Vegetable and fruits collected in the area in distinct years (1996 and 2007 present pesticide in all samples. The samples of lettuce (1996 and watercress (2007 presented the highest rates of parathion-metyl equivalent 0,7 and 1,4 ppm, respectively. The lowest levels were detected in grapes: 0,2 ppm. The solubilization of compounds involved in the study in Triton X-100 were efficient without inhibiting the activity of acetylcholinesterase enzyme. Among the samples studied, lettuce, watercress and apples are valuable in the monitoring of residues of organophosphorus and carbamate pesticides.

Claudia Cristina Machado de Figueiredo de Oliveira

2010-12-01

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A DOSE-RESPONSE STUDY OF THE TOXICITY OF A MIXTURE OF 7N-METHYL CARBAMATE PESTICIDES IN ADULT, MALE RATS.  

Science.gov (United States)

There is scarce knowledge regarding the toxicity of pesticide mixtures, especially mixtures of the anticholinesterase N-methyl carbamates. A mixture study was conducted using 7 N-methyl carbamates (carbaryl, carbofuran, formetanate HCl, methiocarb, methomyl, oxamyl, and propoxur...

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Biodegradation of carbamate pesticides by natural river biofilms in different seasons and their effects on biofilm community structure  

International Nuclear Information System (INIS)

This study investigated the ability of natural river biofilms from different seasons to degrade the carbamate pesticides methomyl, carbaryl and carbofuran in single and multiple pesticide systems, and the effects of these pesticides on algal and bacterial communities within biofilms. Spring biofilms had the lowest biomass of algae and bacteria but showed the highest methomyl degradation (>99%) and dissipation rates, suggesting that they might contain microorganisms with high methomyl degradation abilities. Degradation of carbofuran (54.1–59.5%) by biofilms in four seasons was similar, but low degradation of carbaryl (0–27.5%) was observed. The coexistence of other pesticides was found to cause certain effects on pesticide degradation and primarily resulted in lower diversity of diatoms and bacteria than when using a single pesticide. The tolerant diatoms and bacteria potentially having the ability to degrade test pesticides were identified. River biofilms could be suitable biomaterials or used to isolate degraders for bioremediating pesticide-contaminated water. -- Highlights: •Natural river biofilms showed high ability to degrade methomyl and carbofuran. •The presence of other pesticides caused certain effects on pesticide degradation. •Carbamate pesticides caused adverse effects on communities of diatoms and bacteria. •The tolerant diatoms and bacteria were found as potential pesticide-degraders. -- Biodegradation of carbamate pesticides by river biofilm

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Determination of Carbamate and Organophosphorus Pesticides in Vegetable Samples and the Efficiency of Gamma-Radiation in Their Removal  

OpenAIRE

In the present study, the residual pesticide levels were determined in eggplants (Solanum melongena) (n = 16), purchased from four different markets in Dhaka, Bangladesh. The carbamate and organophosphorus pesticide residual levels were determined by high performance liquid chromatography (HPLC), and the efficiency of gamma radiation on pesticide removal in three different types of vegetables was also studied. Many (50%) of the samples contained pesticides, and three samples had residual leve...

Muhammed Alamgir Zaman Chowdhury; Iffat Jahan; Nurul Karim; Mohammad Khorshed Alam; Mohammad Abdur Rahman; Mohammed Moniruzzaman; Siew Hua Gan; Abu Naieum Muhammad Fakhruddin

2014-01-01

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Bioactive Paper Sensor Based on the Acetylcholinesterase for the Rapid Detection of Organophosphate and Carbamate Pesticides  

Science.gov (United States)

In many countries, people are becoming more concerned about pesticide residues which are present in or on food and feed products. For this reason, several methods have been developed to monitor the pesticide residue levels in food samples. In this study, a bioactive paper-based sensor was developed for detection of acetylcholinesterase (AChE) inhibitors including organophosphate and carbamate pesticides. Based on the Ellman colorimetric assay, the assay strip is composed of a paper support (1 × 10?cm), onto which a biopolymer chitosan gel immobilized in crosslinking by glutaraldehyde with AChE and 5,5?-dithiobis(2-nitrobenzoic) acid (DTNB) and uses acetylthiocholine iodide (ATChI) as an outside reagent. The assay protocol involves introducing the sample to sensing zone via dipping of a pesticide-containing solution. Following an incubation period, the paper is placed into ATChI solution to initiate enzyme catalyzed hydrolysis of the substrate, causing a yellow color change. The absence or decrease of the yellow color indicates the levels of the AChE inhibitors. The biosensor is able to detect organophosphate and carbamate pesticides with good detection limits (methomyl = 6.16 × 10?4?mM and profenofos = 0.27?mM) and rapid response times (~5?min). The results show that the paper-based biosensor is rapid, sensitive, inexpensive, portable, disposable, and easy-to-use. PMID:25484901

Badawy, Mohamed E. I.; El-Aswad, Ahmed F.

2014-01-01

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Retention of carbamate pesticides by different surfactant-modified sorbents: a comparative study  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese Diferentes sorventes sólidos modificados com surfactantes foram investigados comparativamente para a retenção de pesticidas carbamato em solução aquosa. Três sorventes modificados, incluindo alumina tratada com dodecil sulfato de sódio (SDS), sílica revestida com brometo de cetil trimetil amônio (CT [...] AB) e zeólita revestida com CTAB foram preparados usando diferentes concentrações de surfactante. Os pesticidas carbamato estudados incluíram oxamil, metomil, aldicarb, carbofurano, carbaril, isoprocarb, metiocarb, promecarb e carbosulfano e foram analisados por cromatografia líquida de alta eficiência (HPLC) com UV. A adsorção de pesticidas carbamato (faixa de concentração de 0,5-5,0 mg L-1) nos sorventes modificados com surfactante, seguiu regressão linear com os coeficientes de correlação na faixa de 0,857-0,995. A zeólita modificada com CTAB apresentou alta captação para carbofurano, carbaril, metiocarb e carbosulfano. Alumina modificada com SDS demonstrou alta captação de carbaril, isoprocarb, metiocarb, promecarb e carbosulfano. Sílica modificada com CTAB apresentou alta captação de metiocarb, promecarb e carbosulfano. A dessorção dos pesticidas de carbamato dos sorventes modificados com surfactantes usando metanol foram melhores que as obtidas dos sorventes não modificados. O estudo provou que os sorventes modificados com surfactantes são efetivos para a extração de pesticidas carbamato. Abstract in english Different surfactant-modified solid sorbents have been comparatively investigated for retention of carbamate pesticides in aqueous solution. Three modified-sorbents, including sodium dodecyl sulfate (SDS) treated alumina, cetyltrimethyl ammonium bromide (CTAB) coated silica and CTAB coated zeolite, [...] were created using different surfactant concentrations. The studied carbamate pesticides including oxamyl, methomyl, aldicarb, carbofuran, carbaryl, isoprocarb, methiocarb, promecarb and carbosulfan were analyzed by HPLC/UV. Adsorption of all carbamate pesticides (concentration range between 0.5-5.0 mg L-1) onto surfactant-modified sorbents followed linear regressions with the correlation coefficients in the range of 0.857-0.995. CTAB-modified zeolite showed high uptake values for carbofuran, carbaryl, methiocarb and carbosulfan. SDS-modified alumina demonstrated high uptake values for carbaryl, isoprocarb, methiocarb, promecarb and carbosulfan. CTAB-modified silica gave high uptake values for methiocarb, promecarb and carbosulfan. Desorption of carbamate pesticides from surfactant-modified sorbents using methanol were better than that obtained from unmodified sorbents. The study clearly proved that the surfactant-modified sorbents are effective for carbamate pesticides extraction.

Prapha, Arnnok; Rodjana, Burakham.

1720-17-01

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Assessment of Organophosphate and Carbamate Pesticide Residues in Cigarette Tobacco with a Novel Cell Biosensor  

Directory of Open Access Journals (Sweden)

Full Text Available The conventional analysis of pesticide residues in analytical commodities, such as tobacco and tobacco products is a labor intensive procedure, since it is necessary to cover a wide range of different chemicals, using a single procedure. Standard analysis methods include extensive sample pretreatment (with solvent extraction and partitioning phases and determination by GC and HPLC to achieve the necessary selectivity and sensitivity for the different classes of compounds under detection. As a consequence, current methods of analysis provide a limited sample capacity. In the present study, we report on the development of a novel cell biosensor for detecting organophosphate and carbamate pesticide residues in tobacco. The sensor is based on neuroblastoma N2a cells and the measurement of changes of the cell membrane potential, according to the working principle of the Bioelectric Recognition Assay (BERA. The presence of pesticide residues is detected by the degree of inhibition of acetylcholine esterase (AChE. The sensor instantly responded to both the organophoshate pesticide chlorpyriphos and the carbamate carbaryl in a concentration-dependent pattern, being able to detect one part per billion (1 ppb. Additionally, tobacco leaf samples (in blended dry form were analyzed with both the novel biosensor and conventional methods, according to a double-blind protocol. Pesticide residues in tobacco samples caused a considerable cell membrane hyperpolarization to neuroblastoma cells immobilized in the sensor, as indicated by the increase of the negative sensor potential, which was clearly distinguishable from the sensor’s response against pesticide-free control samples. The observed response was quite reproducible, with an average variation of +5,6%. Fluorescence microscopy observations showed that treatment of the cells with either chlorpyrifos or carbaryl was associated with increased [Ca2+]cyt . The novel biosensor offers fresh perspectives for ultra-rapid, sensitive and low-cost monitoring of pesticide residues in tobacco as well as other food and agricultural commodities.

Spiridon Kintzios

2008-04-01

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Early management after self-poisoning with an organophosphorus or carbamate pesticide – a treatment protocol for junior doctors  

OpenAIRE

Severe organophosphorus or carbamate pesticide poisoning is an important clinical problem in many countries of the world. Unfortunately, little clinical research has been performed and little evidence exists with which to determine best therapy. A cohort study of acute pesticide poisoned patients was established in Sri Lanka during 2002; so far, more than 2000 pesticide poisoned patients have been treated. A protocol for the early management of severely ill, unconscious organophosphorus/carba...

Eddleston, Michael; Dawson, Andrew; Karalliedde, Lakshman; Dissanayake, Wasantha; Hittarage, Ariyasena; Azher, Shifa; Buckley, Nick A.

2004-01-01

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Carbamate pesticide-induced apoptosis and necrosis in human natural killer cells.  

Science.gov (United States)

We previously found that ziram, a carbamate fungicide, significantly induced apoptosis and necrosis in human NK-92MI, a natural killer cell line. To investigate whether other carbamate pesticides also induce apoptosis and necrosis in human natural killer cell, we conducted further experiments with NK-92CI, a human natural killer cell line using a more sensitive assay. NK-92CI cells were treated with ziram, thiram, maneb or carbaryl at 0.031-40 microM for 2-24 h in the present study. Apoptosis and necrosis were determined by FITC-Annexin-V/PI staining. To explore the mechanism of apoptosis, intracellular levels of active caspases 3 and mitochondrial cytochrome-c release were determined by flow cytometry. We found that ziram and thiram also induced apoptosis and necrosis in a time- and dose-dependent manner; however, maneb and carbaryl induced apoptosis and necrosis only at higher doses in NK-92CI cells. The strength of the apoptosis-inducing effect differed among the pesticides, and the order was as follows: thiram > ziram greater than maneb greater than carbaryl. NK-92CI was more sensitive to ziram than NK-92MI. Moreover, ziram and thiram significantly increased the intracellular level of active caspase 3 in NK-92CI and caspase inhibitor significantly inhibited the apoptosis. Ziram and thiram significantly caused mitochondrial cytochrome-c release in NK-92CI. These findings indicate that carbamate pesticides can induce apoptosis in natural killer cells, and the apoptosis is mediated by both the caspase-cascade and mitochondrial cytochrome-c pathways. PMID:24750788

Li, Q; Kobayashi, M; Kawada, T

2014-01-01

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Biochemical and Histopathological Changes in The Rat Following Exposure to a Carbamate Pesticide  

International Nuclear Information System (INIS)

Oxamyl is a carbamate pesticide with an oral LD50 of 5.4 mg/kg for male rats. To evaluate the subacute toxicity of the compound, two groups of male rats were dosed with 0.9 and 2.5 mg/kg/day of the pesticide, for 16 days. Toxicological evaluation included clinical chemistry and histopathological changes at the end of the study. The compound significantly altered serum alkaline phosphatase, uric acid, cholesterol, creatinine, blood urea nitrogen (BUN), serum glutamic pyruvic transaminase (SGPT and testosterone. Liver, Kidney and testicular histology revealed mild degenerative changes in the liver with the lower dose and significant degenerative changes with increased lymphocytic infiltrate with the higher dose and mild degenerative changes of the kidney with the higher dose only. Examination of the testis revealed no pathological changes at both dose levels

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MERCAPTOBENZOTHIAZOLE-ON-GOLD ORGANIC PHASE BIOSENSOR SYSTEMS: 2. ENHANCED CARBAMATE PESTICIDE DETERMINATION  

Directory of Open Access Journals (Sweden)

Full Text Available In this paper the results for the construction of a gold/mercaptobenzothiazole/polyaniline/ acetylcholinesterase/polyvinylacetate (Au/MBT/PANI/AChE/PVAc thick-film biosensor for the determination of certain carbamate pesticide solutions in selected aqueous organic solvent solutions are reported. AChE biosensors are designed to complement the classical analytical methods of pesticide detection. The Au/MBT/PANI/AChE/PVAc electrocatalytic biosensor device was constructed by encapsulating acetylcholinesterase (AChE enzyme in the PANI polymer composite, followed by the coating of poly(vinyl acetate (PVAc on top to secure the biosensor film from disintegration in the organic solvents evaluated. The electroactive substrate called acetylthiocholine (ATCh was employed to provide the movement of electrons in the amperometric biosensor. The voltammetric results have shown that the current shifts more anodically as the Au/MBT/PANI/AChE/PVAc biosensor responded to successive acetylthiocholine (ATCh substrate addition under anaerobic conditions in 0.1 M phosphate buffer, KCl (pH 7.2 solution and aqueous organic solvent solutions. For the Au/MBT/PANI/AChE/PVAc biosensor, various performance and stability parameters were evaluated. These factors include the optimal enzyme loading, effect of pH, long-term stability of the biosensor, temperature stability of the biosensor, the effect of polar organic solvents, and the effect of non-polar organic solvents on the amperometric behavior of the biosensor. The biosensor constructed in this study offered a reasonable linear range between 0.25 to 3.45 nM for the detection of carbofuran, aldicarb and dioxacarb pesticide solutions. The detection limits for the individual carbamate pesticides were 0.249 nM for carbofuran, followed by 1.209 nM for aldicarb and 1.572 nM for dioxacarb.

IWUOHA E.

2013-01-01

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Adsorption Kinetics of Carbamate Pesticide in Rice Field Soil  

Directory of Open Access Journals (Sweden)

Full Text Available Ultrasonic extraction (75.55% with petroleum ether:acetone (1:1, v/v was employed for extraction of carbofuran in rice field soil. The amounts of carbofuran were determined by reverse phase HPLC. The analytical method provided high precision and accuracy with the relative error of 0.47%. The percentage of recoveries varied from 84% to 77% in the con¬centration ranges of 10–40 mg/L of spiked soil samples. The carbofuran residues in the rice field soil significantly decreased year by year because of pesticide properties, soil properties and degradation conditions. A high amount of residues was found in the plots that contained high organic contents. The adsorption of carbofuran in soil reached equilibrium within 23 h. The percentage of adsorption varied from almost 30% to 80% depending on concentrations of carbofuran. The adsorption of carbofuran agreed with Freundlich isotherms; q = 7.07 x 10-5Cf2.5092; with the correlation coefficient of 0.9281. Organic carbon coefficient, Koc, was 1.91 x 10-3 mg/L calculated from Kd, and half-life (8.9 d of adsorbed carbofuran. The GUS index (6.37 calculated from Koc presented a high lixiviation potential. The positive ?G indicated the non-spontaneous reaction. Carbofuran rapidly desorbed from soil at the desorption rate of 0.0228 mg/kg soil d. Kinetic studies provided the first order reaction with the reaction rate of 0.0779 mg/d and half-life of 8.9 days.

Soontree Khuntong

2010-07-01

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An evaluation of liquid chromatography/mass spectrometry with atmospheric pressure chemical ionization for the rapid and simultaneous measurement of carbamate pesticides and organophorus pesticides  

International Nuclear Information System (INIS)

Liquid chromatography/mass spectrometry with an atmospheric pressure chemical ionization interface (LC/APCI/MS) is evaluated for the simultaneous determination of carbamate pesticides and organophosphorus pesticides in a single chromatographic analysis. APCI mass spectra of those compounds were obtained to study their ionization characteristics. APCI provided abundant ions such as protonated molecules and characteristic fragment ions for carbamate pesticides and organophosphorus pesticides. To evaluate the feasibility of the LC/APCI/MS for a routine quantitative analysis, the linearity and repeatability of LC/APCI/MS were examined by measuring standard solution mixtures of five carbamate pesticides and four organophosphorus pesticides over the range of 1 to 100 ?g/mL. The peak areas in chromatograms of characteristic ions for those compounds showed less than 3% of variation from run to tun. The standard calibration curves for the nine pesticides show good linearity in the concentration range. The detection limits of the LC/APCI/MS system for those compounds range from 0.006 to 0.2 ng

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RELATIONSHIPS BETWEEN TISSUE LEVELS OF CARBARYL, A PROTOTYPICAL CARBAMATE PESTICIDE, AND CHOLINESTERASE INHIBITION IN LONG EVANS RATS.  

Science.gov (United States)

As part of an effort to link pharmacokinetics with biochemical and physiological endpoints, the relationships between cholinesterase (ChE) activity and tissue levels of a prototypical N-methyl carbamate pesticide were examined. In a dose-response study, carbaryl (0, 3, 7.5, 15, 3...

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Benchmark Dose Analysis from Multiple Datasets: The Cumulative Risk Assessment for the N-Methyl Carbamate Pesticides  

Science.gov (United States)

The US EPA?s N-Methyl Carbamate (NMC) Cumulative Risk assessment was based on the effect on acetylcholine esterase (AChE) activity of exposure to 10 NMC pesticides through dietary, drinking water, and residential exposures, assuming the effects of joint exposure to NMCs is dose-...

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[Analytical method for carbamate pesticides in processed foods by LC/MS/MS].  

Science.gov (United States)

A rapid analytical method for the simultaneous determination of carbamate pesticides in processed foods was established by liquid chromatography coupled with tandem mass spectrometry (LC/MS/MS). The pesticides were extracted from samples with acetonitrile using accelerated solvent extract equipment, except for the fine powder type spices, which were extracted in an ultrasonic bath. The crude extract was cleaned up with a multi-solvent GPC column (Shodex Asahipak GF-310 HQ) using acetonitrile as a mobile phase. The eluent from the column at the retention time between 13 to 18 min was concentrated under nitrogen gas and dissolved in a mixture of acetonitrile-water-0.2 mol/L ammonium formate buffer pH 6.0 (10 : 9 : 1). An aliquot was injected into the LC/MS/MS using electrospray ionization (ESI) with acquisition in the positive mode. The recoveries of 29 kinds of pesticide from dried fruits (raisin, prune and mango) and spices (turmeric, masala, sage, thyme and red pepper) fortified at levels of 0.1 and 0.01 microg/g were mostly in the range of 50 to 150% and those from soybean paste and soy sauce fortified at 0.01 microg/g were 46.9 to 122.6% (C.V. 3.8 to 37.6%), except for 4 kinds of pesticide. The determination limits (S/N> or =10) corresponded to 0.001 to 0.05 mug/g of the pesticides in red pepper. PMID:18633196

Terada, Hisaya; Noguchi, Shoichiro; Maruyama, Yoshimasa; Kato, Haruyasu; Tamura, Yukio; Oka, Hisao

2008-06-01

31

A ONE STEP METHOD FOR THE DETERMINATION OF CARBAMATE PESTICIDES BY DERIVATIZATION WITH ALPHA-BROMO-2,3,4,5,6-PENTAFLUOROTOLUENE  

Science.gov (United States)

A procedure was developed for the determination of trace quantities of a broad range of carbamate pesticides. The carbamates were hydrolyzed and derivatized in a single step, using alkali and alpha-bromo-2,3,4,5,6-pentafluorotoluene (PFBB), and were subsequently analyzed using el...

32

Laccase-Prussian blue film-graphene doped carbon paste modified electrode for carbamate pesticides quantification.  

Science.gov (United States)

A novel enzymatic biosensor for carbamate pesticides detection was developed through the direct immobilization of Trametes versicolor laccase on graphene doped carbon paste electrode functionalized with Prussian blue films (LACC/PB/GPE). Graphene was prepared by graphite sonication-assisted exfoliation and characterized by transmission electron microscopy and X-ray photoelectron spectroscopy. The Prussian blue film electrodeposited onto graphene doped carbon paste electrode allowed considerable reduction of the charge transfer resistance and of the capacitance of the device. The combined effects of pH, enzyme concentration and incubation time on biosensor response were optimized using a 2(3) full-factorial statistical design and response surface methodology. Based on the inhibition of laccase activity and using 4-aminophenol as redox mediator at pH 5.0, LACC/PB/GPE exhibited suitable characteristics in terms of sensitivity, intra- and inter-day repeatability (1.8-3.8% RSD), reproducibility (4.1 and 6.3% RSD), selectivity (13.2% bias at the higher interference:substrate ratios tested), accuracy and stability (ca. twenty days) for quantification of five carbamates widely applied on tomato and potato crops. The attained detection limits ranged between 5.2×10(-9)molL(-1) (0.002mgkg(-1) w/w for ziram) and 1.0×10(-7)molL(-1) (0.022mgkg(-1) w/w for carbofuran). Recovery values for the two tested spiking levels ranged from 90.2±0.1 (carbofuran) to 101.1±0.3% (ziram) for tomato and from 91.0±0.1% (formetanate) to 100.8±0.1% (ziram) for potato samples. The proposed methodology is appropriate to enable testing pesticide levels in food samples to fit with regulations and food inspections. PMID:23587791

Oliveira, Thiago M B F; Fátima Barroso, M; Morais, Simone; Araújo, Mariana; Freire, Cristina; de Lima-Neto, Pedro; Correia, Adriana N; Oliveira, Maria B P P; Delerue-Matos, Cristina

2013-09-15

33

Factorial design optimization of experimental variables in preconcentration of carbamates pesticides in water samples using solid phase extraction and liquid chromatography-electrospray-mass spectrometry determination.  

Science.gov (United States)

An experimental design was applied for the optimization of extraction process of carbamates pesticides from surface water samples. Solid phase extraction (SPE) of carbamates compounds and their determination by liquid chromatography coupled to electrospray mass spectrometry detector were considered. A two level full factorial design 2(k) was used for selecting the variables which affected the extraction procedure. Eluent and sample volumes were statistically the most significant parameters. These significant variables were optimized using Doehlert matrix. The developed SPE method included 200mg of C-18 sorbent, 143.5 mL of water sample and 5.5 mL of acetonitrile in the elution step. For validation of the technique, accuracy, precision, detection and quantification limits, linearity, sensibility and selectivity were evaluated. Extraction recovery percentages of all the carbamates were above 90% with relative standard deviations (R.S.D.) in the range of 3-11%. The extraction method was selective and the detection and quantification limits were between 0.1 and 0.5 µg L(-1), and 1 and 3 µg L(-1), respectively. PMID:24209358

Latrous El Atrache, Latifa; Ben Sghaier, Rafika; Bejaoui Kefi, Bochra; Haldys, Violette; Dachraoui, Mohamed; Tortajada, Jeanine

2013-12-15

34

Probabilistic assessment of the cumulative dietary acute exposure of the population of Denmark to organophosphorus and carbamate pesticides  

DEFF Research Database (Denmark)

Organophosphorus and carbamate pesticides are acetylcholinesterase-inhibiting pesticides and as such have a common mode of action. We assessed the cumulative acute exposure of the population of Denmark to 25 organophosphorus and carbamate pesticide residues from the consumption of fruit, vegetables and cereals. The probabilistic approach was used in the assessments. Residue data obtained from the Danish monitoring programme carried out in the period 2004-2007, which included 6704 samples of fruit, vegetables and cereals, were used in the calculations. Food consumption data were obtained from the nationwide dietary survey conducted in 2000-2002. Contributions from 43 commodities were included in the calculations. We used the relative potency factor (RPF) approach to normalize the toxicity of the various organophosphorus and carbamate pesticides to the two index compounds chlorpyriphos and methamidophos. RPF values derived from the literature were used in the calculations. We calculated the cumulative acute exposure to 1.8% and 0.8% of the acute reference dose (ARfD) of 100 mu g kg(-1) body weight (bw) day(-1) of chlorpyrifos as an index compound at the 99.9th percentile (P99.5) for children and adults, respectively. When we used methamidophos as the index compound, the cumulative acute intakes were calculated to 31.3% and 13.8% of the ARfD of 3 mu g kg(-1) bw day(-1) at P99.9 for children and adults, respectively. With both index compounds, the greatest contributor to the cumulative acute exposure was apple. The results show that there is no cumulative acute risk for Danish consumers to acetylcholinesterase- inhibiting pesticides.

Jensen, Bodil Hamborg; Petersen, Annette

2009-01-01

35

Immobilization of acetylcholinesterase via biocompatible interface of silk fibroin for detection of organophosphate and carbamate pesticides  

International Nuclear Information System (INIS)

An amperometric biosensor for the detection of organophosphate and carbamate pesticides was developed based on the immobilization of acetylcholinesterase (AChE) on regenerated silk fibroin (SF) matrix by non-covalent adsorption. SF and AChE were coated sequentially on the surface of the glassy carbon electrode (GCE) which was modified with multiwall carbon nanotube (MWNTs). The obtained biosensor was denoted as AChE-SF/MWNTs/GCE. The atomic force microscopy images showed that the SF matrix provided a more homogeneous interface for the AChE immobilization. The aggregation of immobilizing AChE was therefore avoided. The cyclic voltammogram of thiocholine at this biosensor exhibited a well defined oxidation peak at 0.667 V (vs. SCE). The inhibition rate of methyl parathion to the immobilized AChE was proportional to the logarithm of the concentration of methyl parathion over the range of the concentration of methyl parathion from 3.5 × 10-6 to 2.0 × 10-3 M with a detection limit of 5.0 × 10-7 M. Similarly, the linearly response range of carbaryl was from 1.0 × 10-7 to 3.0 × 10-5 M with a detection limit of 6.0 × 10-8 M. The experimental results indicate that AChE not only can be immobilized steadily on the SF matrix, but also the bioactivity of immobilizing AChE can be preserved effectively.

36

Comparative voltammetric study and determination of carbamate pesticide residues in soil at carbon nanotubes paste electrodes  

Directory of Open Access Journals (Sweden)

Full Text Available In this investigation, the persistence of carbamate pesticides in soil samples was investigated. A simple and selective differential pulse adsorptive stripping voltammetry was selected for this investigation. Carbon nanotubes paste electrodes were used as working electrodes for differential pulse adsorptive stripping voltammetry and cyclic voltammetry. A symmetric study of the various operational parameters that affect the stripping response was carried out by differential pulse voltammetry. Peak currents were linear over the concentration range of 10-5 to 10-10 M with an accumulation potential of -0.6 V and a 70 s accumulation time with lower detection limits of 1.09 x 10-7 M, 1.07 × 10-7M, 1.09×10-7 M for chlorphropham, thiodicarb, aldicarb. The relative standard deviation (n=10 and correlation coefficient values were 1.15 %, 0.988; 1.13 %, 0.978; and 1.14 %, 0.987, respectively. Universal buffer with pH range 2.0 - 6.0 was used as sup­porting electrolyte. The solutions with uniform concentration (10-5 M were used in all deter­minations. Calculations were made by standard addition method.

THOMMANDRU RAVEENDRANATH BAB

2014-02-01

37

Immobilization of acetylcholinesterase via biocompatible interface of silk fibroin for detection of organophosphate and carbamate pesticides  

Science.gov (United States)

An amperometric biosensor for the detection of organophosphate and carbamate pesticides was developed based on the immobilization of acetylcholinesterase (AChE) on regenerated silk fibroin (SF) matrix by non-covalent adsorption. SF and AChE were coated sequentially on the surface of the glassy carbon electrode (GCE) which was modified with multiwall carbon nanotube (MWNTs). The obtained biosensor was denoted as AChE-SF/MWNTs/GCE. The atomic force microscopy images showed that the SF matrix provided a more homogeneous interface for the AChE immobilization. The aggregation of immobilizing AChE was therefore avoided. The cyclic voltammogram of thiocholine at this biosensor exhibited a well defined oxidation peak at 0.667 V (vs. SCE). The inhibition rate of methyl parathion to the immobilized AChE was proportional to the logarithm of the concentration of methyl parathion over the range of the concentration of methyl parathion from 3.5 × 10-6 to 2.0 × 10-3 M with a detection limit of 5.0 × 10-7 M. Similarly, the linearly response range of carbaryl was from 1.0 × 10-7 to 3.0 × 10-5 M with a detection limit of 6.0 × 10-8 M. The experimental results indicate that AChE not only can be immobilized steadily on the SF matrix, but also the bioactivity of immobilizing AChE can be preserved effectively.

Xue, Rui; Kang, Tian-Fang; Lu, Li-Ping; Cheng, Shui-Yuan

2012-06-01

38

Immobilization of acetylcholinesterase via biocompatible interface of silk fibroin for detection of organophosphate and carbamate pesticides  

Energy Technology Data Exchange (ETDEWEB)

An amperometric biosensor for the detection of organophosphate and carbamate pesticides was developed based on the immobilization of acetylcholinesterase (AChE) on regenerated silk fibroin (SF) matrix by non-covalent adsorption. SF and AChE were coated sequentially on the surface of the glassy carbon electrode (GCE) which was modified with multiwall carbon nanotube (MWNTs). The obtained biosensor was denoted as AChE-SF/MWNTs/GCE. The atomic force microscopy images showed that the SF matrix provided a more homogeneous interface for the AChE immobilization. The aggregation of immobilizing AChE was therefore avoided. The cyclic voltammogram of thiocholine at this biosensor exhibited a well defined oxidation peak at 0.667 V (vs. SCE). The inhibition rate of methyl parathion to the immobilized AChE was proportional to the logarithm of the concentration of methyl parathion over the range of the concentration of methyl parathion from 3.5 Multiplication-Sign 10{sup -6} to 2.0 Multiplication-Sign 10{sup -3} M with a detection limit of 5.0 Multiplication-Sign 10{sup -7} M. Similarly, the linearly response range of carbaryl was from 1.0 Multiplication-Sign 10{sup -7} to 3.0 Multiplication-Sign 10{sup -5} M with a detection limit of 6.0 Multiplication-Sign 10{sup -8} M. The experimental results indicate that AChE not only can be immobilized steadily on the SF matrix, but also the bioactivity of immobilizing AChE can be preserved effectively.

Xue Rui [College of Environmental and Energy Engineering, Beijing University of Technology, Beijing 100124 (China); Kang Tianfang, E-mail: kangtf@yahoo.cn [College of Environmental and Energy Engineering, Beijing University of Technology, Beijing 100124 (China); Lu Liping; Cheng Shuiyuan [College of Environmental and Energy Engineering, Beijing University of Technology, Beijing 100124 (China)

2012-06-01

39

Rapid and sensitive suspension array for multiplex detection of organophosphorus pesticides and carbamate pesticides based on silica-hydrogel hybrid microbeads.  

Science.gov (United States)

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. PMID:24769809

Wang, Xuan; Mu, Zhongde; Shangguan, Fengqi; Liu, Ran; Pu, Yuepu; Yin, Lihong

2014-05-30

40

Extraction of carbamate pesticides in fruit samples by graphene reinforced hollow fibre liquid microextraction followed by high performance liquid chromatographic detection.  

Science.gov (United States)

Graphene reinforced hollow fibre liquid phase microextraction combined with high performance liquid chromatography-diode array detection was developed for the determination of some carbamate pesticides (metolcarb, carbaryl, isoprocarb, and diethofencarb) in fruit samples. The main parameters that affect the extraction efficiency for the carbamates were investigated. Under the optimum conditions, a good linearity was observed in the range of 1.0-100.0 ng g(-1) for carbaryl and 3.0-100.0 ng g(-1) for the other three analytes, with the correlation coefficients (r) of 0.9965-0.9993. The limits of detection of the method ranged from 0.2 to 1.0 ng g(-1). The relative standard deviations were in the range from 6.2% to 7.8%. The results indicated that the developed method is sensitive and efficient for the determination of the carbamate pesticides in fruit samples. PMID:24679760

Ma, Xiaoxing; Wang, Juntao; Wu, Qiuhua; Wang, Chun; Wang, Zhi

2014-08-15

41

Immunomodulation of human natural killer cell cytotoxic function by triazine and carbamate pesticides.  

Science.gov (United States)

Triazine (atrazine) and carbamates (maneb, metiram, and ziram) are used as pesticides on a variety of crops around the world. To our knowledge, there have been no studies dealing with the effects of these compounds on human natural killer (NK) cells cytotoxic function. NK cells play a central role in immune defense against tumor development and viral infections. Thus, any agent that interferes with the ability of NK cells to lyse their targets could increase the risk of tumor incidence and/or viral infections. In this study, we examined the effects of atrazine, maneb, metiram, zineb, and ziram on the ability of human NK cells to lyse tumor cells. The compounds were tested in both purified NK cells as well as a cell preparation that contained both T and NK lymphocytes (T/NK cells). Lymphocytes were exposed to the compounds for periods of time ranging from 1 h to 6 days. Exposure of highly purified NK cells to 10 microM atrazine, maneb, or metiram inhibited K562 tumor cell lysis by 63+/-25, 95+/-4, and 50+/-6%, respectively, after a 24 h exposure and by 83+/-21, 70+/-39, and 48+/-41% after a 6-day exposure. Exposure to 2.5 microM ziram for 24 h caused a 99+/-2% decrease in lytic function and at 1 microM for 6 days caused a 96+/-4% decrease. However, when T/NK cells were exposed to atrazine, maneb, or metiram for 24 h only 10 microM atrazine and maneb caused a significant decreases in lytic function (61+/-13 and 38+/-18%) and after 6 days only atrazine was inhibitory (54+/-12%). A 24-h exposure to 2.5-microM ziram caused a 41+/-51% decrease in function, but a 6-day exposure to 1 microM ziram caused no inhibition of lytic function. The results provide evidence of relative toxic potential for the five compounds and the immunomodulatory effects on both T and NK lymphocyte function. PMID:12732457

Whalen, Margaret M; Loganathan, Bommanna G; Yamashita, Nobuyoshi; Saito, Takao

2003-06-15

42

Dispersive solid-phase extraction cleanup combined with accelerated solvent extraction for the determination of carbamate pesticide residues in Radix Glycyrrhizae samples by UPLC-MS-MS.  

Science.gov (United States)

Dispersive solid-phase extraction (DSPE) cleanup combined with accelerated solvent extraction (ASE) is described here as a new approach for the extraction of carbamate pesticides in Radix Glycyrrhizae samples prior to UPLC-MS-MS. In the DSPE-ASE method, 15 carbamate pesticides were extracted from Radix Glycyrrhizae samples with acetonitrile by the ASE method at 60 °C with a 5 min heating time and two static cycles. Cleanup of a 1 mL aliquot of the extract by the DSPE method used 20 mg PSA (primary secondary amine), 50 mg Al(2)O(3)-N, and 20 mg GCB (graphitized carbon black) (as cleanup sorbents) under the determined optimum conditions. The linearity of the method was in the range of 10 to 200 ng/mL with correlation coefficients (r(2)) of more than 0.996. The limits of detection were approximately 0.2 to 5.0 µg/kg. The method was successfully used for the analysis of target pesticides in Radix Glycyrrhizae samples. The recoveries of the carbamate pesticides at the spiking levels of 50, 100, and 200 µg/kg ranged from 79.7% to 99.3% with relative standard deviations lower than 10%. This multi-residue analytical method allows for a rapid, efficient, sensitive and reliable determination of target pesticides in Radix Glycyrrhizae and other medicinal herbs. PMID:22586247

Yang, Ru-zhen; Wang, Jin-hua; Wang, Ming-lin; Zhang, Rong; Lu, Xiao-yu; Liu, Wei-hua

2011-10-01

43

Monitoring of N-methyl carbamate pesticide residues in water using hollow fibre supported liquid membrane and solid phase extraction  

Science.gov (United States)

The aim of this work was to develop a method for the determination of N-methyl carbamates in water involving hollow fibre supported liquid membrane (HFSLM) and solid phase extraction (SPE) as sample preparation methods. Four N-methyl carbamate pesticides, aldicarb, carbaryl, carbofuran and methiocarb sulfoxide, were simultaneously extracted and analysed by a liquid chromatograph with a diode array detector (LC-UV/DAD) and a liquid chromatograph coupled to a ion trap quadrupole mass spectrometer (LC-ESI-MS). The high performance liquid chromatography (HPLC) separation of carabamate extracts was performed on a C18 column with water-acetonitrile as the mobile phase. The mass spectrometry analyses were carried out in the positive mode, operating under both the selected ion monitoring (SIM) and full scan modes. The solid phase recoveries of the extracts ranged between 8% and 98%, with aldicarb having the highest recoveries, followed by carbaryl, carbofuran and methiocarb had the lowest recovery. The HFSLM recovery ranged between 8% and 58% and the order of recovery was similar to the SPE trend. Factors controlling the efficiency of the HFSLM extraction such as sample pH, stripping phase pH, enrichment time, stirring speed as well as organic solvent used for entrapment of analytes, were optimised to achieve the highest enrichment factors.

Msagati, Titus A. M.; Mamba, Bhekie B.

44

Antioxidant and oxidative stress related responses in the Mediterranean land snail Cantareus apertus exposed to the carbamate pesticide Carbaryl.  

Science.gov (United States)

The aim of the present work was to study the alterations of the antioxidant defenses and the overall susceptibility to oxidative stress of the terrestrial snail Cantareus apertus exposed to the carbamate pesticide Carbaryl at a low environmentally realistic concentration. The animals were exposed to Lactuca sativa soaked for 1h in 1?M Carbaryl. The temporal dynamics of the responses was assessed by measurements at 3, 7 and 14days of exposure. C. apertus exposed to Carbaryl activates a number of enzymatic antioxidant responses, represented by the early induction of catalase, glutathione peroxidase, glutathione reductase, followed by a delayed induction of superoxide dismutase. Concomitantly, a derangement of the total oxyradical scavenging of the tissues was observed, suggesting an overall impairment of the tissue capability to neutralize ROS probably resulting from the overall negative balance between enzymatic antioxidant defense capability and oxidative stress intensity. This negative balance exposed the animals to the risk of oxidative stress damages including genotoxic damage. Compared to acetylcholinesterase inhibition, the antioxidant responses developed to Carbaryl exposure at the low concentration utilized showed a greater percentage variation in exposed organisms. The results pointed out the high sensitivity of the antioxidant and oxidative stress related responses to Carbaryl exposure at an environmental realistic concentration, demonstrating their usefulness in environmental monitoring and risk assessment. The study highlights also the usefulness of the terrestrial snail C. apertus as potential bioindicator species for assessing the risk of pesticide environmental contamination. PMID:25451076

Leomanni, A; Schettino, T; Calisi, A; Gorbi, S; Mezzelani, M; Regoli, F; Lionetto, M G

2015-02-01

45

DOSE-TIME-RESPONSE MODELING FOR EVALUATING CUMULATIVE RISK OF N -METHYL CARBAMATE PESTICIDES  

Science.gov (United States)

EPA's Office of Prevention, Pesticides, and Toxic Substances (OPPTS) is required by the Food Quality Protection Act to completely reevaluate pesticide registrations by the end of August, 2006. This evaluation must include the evaluation of cumulative and aggregate risk of compou...

46

Development of a Computer-Based Survey Instrument for Organophosphate and N-Methyl-Carbamate Exposure Assessment among Agricultural Pesticide Handlers  

OpenAIRE

Background: Assessment of occupational pesticide exposures based on self-reported information can be challenging, particularly with immigrant farm worker populations for whom specialized methods are needed to address language and cultural barriers and account for limited literacy. An audio computer-assisted self-interview (A-CASI) survey instrument was developed to collect information about organophosphate (OP) and N-methyl-carbamate (CB) exposures and other personal characteristics among mal...

Hofmann, Jonathan N.; Checkoway, Harvey; Borges, Ofelio; Servin, Flor; Fenske, Richard A.; Keifer, Matthew C.

2010-01-01

47

Organophosphorus and Carbamate Pesticide Residues Detected in Water Samples Collected from Paddy and Vegetable Fields of the Savar and Dhamrai Upazilas in Bangladesh  

Directory of Open Access Journals (Sweden)

Full Text Available Several types of organophosphorous and carbamate pesticides have been used extensively by the farmers in Bangladesh during the last few decades. Twenty seven water samples collected from both paddy and vegetable fields in the Savar and Dhamrai Upazilas in Bangladesh were analyzed to determine the occurrence and distribution of organo-phosphorus (chlorpyrifos, malathion and diazinon and carbamate (carbaryl and carbofuran pesticide residues. A high performance liquid chromatograph instrument equipped with a photodiode array detector was used to determine the concentrations of these pesticide residues. Diazinon and carbofuran were detected in water samples collected from Savar Upazila at 0.9 ?g/L and 198.7 ?g/L, respectively. Malathion was also detected in a single water sample at 105.2 ?g/L from Dhamrai Upazila. Carbaryl was the most common pesticide detected in Dhamrai Upazila at 14.1 and 18.1 ?g/L, while another water sample from Dhamrai Upazila was contaminated with carbofuran at 105.2 ?g/L. Chlorpyrifos was not detected in any sample. Overall, the pesticide residues detected were well above the maximum acceptable levels of total and individual pesticide contamination, at 0.5 and 0.1 ?g/L, respectively, in water samples recommended by the European Economic Community (Directive 98/83/EC. The presence of these pesticide residues may be attributed by their intense use by the farmers living in these areas. Proper handling of these pesticides should be ensured to avoid direct or indirect exposure to these pesticides.

Nurul Karim

2012-09-01

48

Determination of the residues of 18 carbamate pesticides in chestnut and pine nut by GPC cleanup and UPLC-MS-MS.  

Science.gov (United States)

A new method using gel permeation chromatography (GPC) cleanup followed by ultra-performance liquid chromatography combined with tandem mass spectrometry (UPLC-MS-MS) has been established for simultaneous determination of 18 carbamate pesticides in nuts (chestnut and pine nut). Recoveries obtained by fortifying nut (spiking at 0.02 mg/kg) range from 70.21% to 89.56%. The proposed method features good sensitivity. Its limits of quantification are low enough to allow pesticide residues to be determined at concentrations below the maximum residue levels legally accepted. The precision, expressed as relative standard deviation, ranges from 2.26% to 4.07%. PMID:20056028

Lin, Qin-Bao; Xue, Yuan-Yuan; Song, Huan

2010-01-01

49

Age-related differences in neurotoxicity produced by organophosphorus and N-methyl carbamate pesticides  

Science.gov (United States)

Potential pesticide effects in infants and toddlers have received much attention in the scientific literature and the public media, including the concern for increased response to acute or shortterm exposures. Age-related differences in the acute neurotoxicity of acetylcholinest...

50

SELECTIVE ISOLATION OF A GRAM NEGATIVE CARBAMATE PESTICIDE DEGRADING BACTERIUM FROM BRINJAL CULTIVATED SOIL  

OpenAIRE

A bacterial species having the ability to grow in the presence of carbosulfan pesticide â??Marshallâ? was isolated from Solanum melongena (brinjal) cultivated soil in Khulna region, Bangladeh, having a history of pesticide usage. The strain was morphologically and biochemically identified to belong to the genera Pseudomonas. A comparative study of growth of this strain with other isolated bacteria showed its ability to grow in the presence of different concentrations of M...

Dilara Islam Sharif; Mithun Mollick

2013-01-01

51

Effects of in vitro exposure to low levels of organotin and carbamate pesticides on human natural killer cell cytotoxic function.  

Science.gov (United States)

Human natural killer (NK) lymphocytes play a central role in immune system defense against viral infection and against the formation of primary tumors. Organotin (OT) pesticides have been used in industrial and agricultural applications, and OT contamination has been reported in water, sediment, and fish. Carbamate pesticides are currently used in agricultural chemicals. Two specific carbamates used in agriculture are ziram and maneb; ziram also is used as an additive in rubber products including latex gloves. In previous studies we demonstrated that at concentrations in the 150-200 nM range, the OTs tributyltin (TBT) and triphenyltin (TPT) were capable of disrupting the function of human NK cells after incubations to as short as 24 h. Previously, we also examined the effects of ziram and maneb at higher concentrations on the cytotoxic function of human NK cells. The current study examined the effects of exposure of up to 6 days to lower concentrations of each of these compounds on the cytotoxic function of NK cells. The OTs were studied at concentrations ranging from 200 to 10 nM; ziram was studied at concentrations of 2.5 microM-125 nM and maneb at concentrations of 10-1 microM. These conditions were studied both in highly purified NK cells and in a mixture of lymphocytes containing both T and NK cells. As little as 25 nM TBT decreased the function of purified NK cells after 24 and 48 h, whereas 10 nM TBT was effective after 6 days. The lowest level of TPT that was effective at 24 h was 50 nM whereas the results after 48 h and 6 days were similar to those seen with TBT. The presence of T lymphocytes diminished the effects of both TBT and TPT on NK cytotoxic function. A concentration of ziram as low as 125 nM produced significant loss of cytotoxic function in highly purified NK cells (65% decrease in function after 6 days). The toxicity of each of the compounds studied increased very significantly with length of exposure. PMID:15526271

Wilson, Sharnise; Dzon, Leticia; Reed, Adrian; Pruitt, Marilyn; Whalen, Margaret M

2004-12-01

52

Graphene based solid phase extraction combined with ultra high performance liquid chromatography-tandem mass spectrometry for carbamate pesticides analysis in environmental water samples.  

Science.gov (United States)

In this paper, graphene, a new sorbent material, was synthesized and used for solid-phase extraction (SPE) of the six carbamate pesticides (pirimicarb, baygon, carbaryl, isoprocarb, baycarb and diethofencarb) in environmental water samples. The target analytes can be extracted on the graphene-packed SPE cartridge, and then eluted with acetone. The eluate was collected and dried by high purity nitrogen gas at room temperature. 1mL of 20% (v/v) acetonitrile aqueous solution was used to redissolve the residue. The final sample solution was analyzed by ultra performance liquid chromatography-tandem quadrupole mass spectrometry (UPLC-MS/MS) system. Under optimum conditions, good linearity was obtained for the carbamates with correlation coefficient in the range of 0.9992-0.9998. The limits of detection (S/N=3) for the six carbamate pesticides were in the range of 0.5-6.9ngL(-1). Relative standard deviations (RSD) for five replicate determinations were below 5.54%. RSD values for cartridge-to-cartridge precision (n=7) were in the range of 1.27-8.13%. After proper regeneration, the graphene-packed SPE cartridge could be re-used over 100 times for standard solution without significant loss of performance. The enrichment factors for the target analytes were in the range of 34.2-51.7. The established method has been successfully applied to the determination of carbamate pesticide residues in environmental water samples such as river water, well water and lake water. PMID:24973804

Shi, Zhihong; Hu, Junda; Li, Qi; Zhang, Shulan; Liang, Yuhuan; Zhang, Hongyi

2014-08-15

53

SELECTIVE ISOLATION OF A GRAM NEGATIVE CARBAMATE PESTICIDE DEGRADING BACTERIUM FROM BRINJAL CULTIVATED SOIL  

Directory of Open Access Journals (Sweden)

Full Text Available A bacterial species having the ability to grow in the presence of carbosulfan pesticide â??Marshallâ? was isolated from Solanum melongena (brinjal cultivated soil in Khulna region, Bangladeh, having a history of pesticide usage. The strain was morphologically and biochemically identified to belong to the genera Pseudomonas. A comparative study of growth of this strain with other isolated bacteria showed its ability to grow in the presence of different concentrations of Marshall. The susceptibility of the stain to Marshall was also assessed through disk diffusion assay which showed the strain to be resistant at concentrations of Marshal commonly used under field conditions. The selected strain also showed its capability to degrade Marshall through observed characteristics on sublimated agar plates. The biodegradation capability of the strain isolated in this study can be valuable for further study towards bioremediation of pesticide contaminated soils.

Dilara Islam Sharif

2013-01-01

54

Multi photon ionization mass spectrometry of carbamate pesticides, herbicides and fungicides  

International Nuclear Information System (INIS)

Pesticides and herbicides are useful for a wide range of applications today. The determination of these substances either in the pure form or in complex matrices is of high analytical interest. Especially since these substances can by found in every day products. The combination of multi photon ionization (MUPI) and time of flight laser mass spectrometry may be a powerful tool for achieving fast well interpretable mass spectra for analytical purposes. In this paper we will discuss the mass spectra of several pesticides and herbicides accessed by MUPI-time-of-flight mass spectrometry. The influence of the laser pulse duration on the mass spectra are discussed

55

Multi photon ionization mass spectrometry of carbamate pesticides, herbicides and fungicides  

Science.gov (United States)

Pesticides and herbicides are useful for a wide range of applications today. The determination of these substances either in the pure form or in complex matrices is of high analytical interest. Especially since these substances can by found in every day products. The combination of multi photon ionization (MUPI) and time of flight laser mass spectrometry may be a powerful tool for achieving fast well interpretable mass spectra for analytical purposes. In this paper we will discuss the mass spectra of several pesticides and herbicides accessed by MUPI-time-of-flight mass spectrometry. The influence of the laser pulse duration on the mass spectra are discussed.

Grun, Carsten; König, Marcelle; Grotemeyer, Jürgen

2001-08-01

56

Allergic reaction induced by dermal and/or respiratory exposure to low-dose phenoxyacetic acid, organophosphorus, and carbamate pesticides  

International Nuclear Information System (INIS)

Several types of pesticides, such as organophosphates, phenoxyacetic acid, and carbamate have a high risk of affecting human health, causing allergic rhinitis and bronchial asthma-like diseases. We used our long-term sensitization method and a local lymph node assay to examine the allergic reactions caused by several types of pesticides. BALB/c mice were topically sensitized (9 times in 3 weeks), then challenged dermally or intratracheally with 2,4-D, BRP, or furathiocarb. One day post-challenge, the mice were processed to obtain biologic materials for use in assays of total IgE levels in serum and bronchoalveolar lavage fluid (BALF); differential cell counts and chemokine levels in BALF; lymphocyte counts and surface antigen expression on B-cells within regional lymph nodes (LNs); and, ex situ cytokine production by cells from these LNs. 2,4-D-induced immune responses characteristic of immediate-type respiratory reactions, as evidenced by increased total IgE levels in both serum and BALF; an influx of eosinophils, neutrophils, and chemokines (MCP-1, eotaxin, and MIP-1?) in BALF; increased surface antigen expression on B-cells IgE and MHC class II production) in both auricular and the lung-associated LNs; and increased Th2 cytokine production (IL-4, IL-5, IL-10, and IL-13) in both auricular and the lung-associated LN cells. In contrast, BRP and furathiocarb treatment yielded, at most, non-significant increases in all respiratory allergic parameters. BRP and furathiocarb induced marked proliferation of MHC Class II-positive B-cells and Th1 cytokines (IL-2, TNF-?, and IFN-?) in only auricular LN cells. These results suggest that 2,4-D is a respiratory allergen and BRP and furathiocarb are contact allergens. As our protocol detected classified allergic responses to low-molecular-weight chemicals, it thus may be useful for detecting environmental chemical-related allergy.

57

Sequential injection kinetic spectrophotometric determination of quaternary mixtures of carbamate pesticides in water and fruit samples using artificial neural networks for multivariate calibration  

Science.gov (United States)

A new analytical method was developed for the simultaneous kinetic spectrophotometric determination of a quaternary carbamate pesticide mixture consisting of carbofuran, propoxur, metolcarb and fenobucarb using sequential injection analysis (SIA). The procedure was based upon the different kinetic properties between the analytes reacted with reagent in flow system in the non-stopped-flow mode, in which their hydrolysis products coupled with diazotized p-nitroaniline in an alkaline medium to form the corresponding colored complexes. The absorbance data from SIA peak time profile were recorded at 510 nm and resolved by the use of back-propagation-artificial neural network (BP-ANN) algorithms for multivariate quantitative analysis. The experimental variables and main network parameters were optimized and each of the pesticides could be determined in the concentration range of 0.5-10.0 ?g mL -1, at a sampling frequency of 18 h -1. The proposed method was compared to other spectrophotometric methods for simultaneous determination of mixtures of carbamate pesticides, and it was proved to be adequately reliable and was successfully applied to the simultaneous determination of the four pesticide residues in water and fruit samples, obtaining the satisfactory results based on recovery studies (84.7-116.0%).

Chu, Ning; Fan, Shihua

2009-12-01

58

Age-related differences in acetylcholinesterase inhibition produced by organophosphorus and N-methyl carbamate pesticides  

Science.gov (United States)

Introduction The concern that infants and children may be more susceptible to the toxic effects of chemicals, including pesticides, has received much attention in the scientific literature and the public media. Greater toxicity may be evident as long-term adverse outcomes, e.g.,...

59

THE DETERMINATION OF CARBAMATE AND UREA PESTICIDES IN INDUSTRIAL AND MUNICIPAL WASTEWATER: METHOD 632  

Science.gov (United States)

This is a high performance liquid chromatographic (HPLC) method applicable to the determination of selected pesticides in municipal and industrial discharges as provided under 40CFR 136.1. A sample is solvent extracted with methylene chloride using a separatory funnel. The extrac...

60

Determination of poorly fluorescent carbamate pesticides in water, bendiocarb and promecarb, using cyclodextrin nanocavities and related media  

Energy Technology Data Exchange (ETDEWEB)

The effect of native cyclodextrins ({alpha}, {beta}, or {gamma}CD with six, seven and eight glucose units, respectively), hydroxypropyl-{beta}-cyclodextrin (HPCD), chitosan (CHT) and glucose in water solution or water with n-propylamine (PA) as co-solvent upon the UV-vis and fluorescence properties of poorly fluorescent N-methyl carbamates pesticides (C) as bendiocarb (2,2-dimethyl-1,3-benzodioxol-4-ol methylcarbamate, BC) and promecarb (3-methyl-5-(1-methylethyl)phenol methylcarbame, PC) was examined. Fluorescent enhancement was found for both substrates with all CDs in water or PA-water except from PC with {alpha}CD. The addition of CHT increases the fluorescence of BC but decreases the fluorescence of PC, and glucose addition gives in both cases no spectral changes. Host-guest interaction was clearly determined by fluorescence enhancement with {beta}CD and HPCD with a 1:1 stoichiometry for the complexes (C:CD). The values obtained for the association constants (K {sub A}, M{sup -1}) were (6 {+-} 2) x 10{sup 2} and (2.3 {+-} 0.3) x 10{sup 2} for BC:{beta}CD and BC:HPCD complexes, respectively. For PC:{beta}CD and PC:HPCD the values of K {sub A} were (19 {+-} 2) x 10{sup 2} and (21 {+-} 2) x 10{sup 2}, respectively. The ratio of the fluorescence quantum yields for the bound and free substrates ({phi} {sup CCD}/{phi} {sup C}) was in the range 1.74-3.8. The limits of detection (L {sub D}, {mu}g mL{sup -1}) for the best conditions were (0.57 {+-} 0.02) for BC with HPCD and (0.091 {+-} 0.002) for PC with {beta}CD in water. Application to the analysis in pesticide spiked samples of tap water and fruit yields satisfactory apparent recoveries (84-114%), and for the extraction procedure in fruits and a commercial formulation, recoveries were of 81-98% and 104%, respectively. The method is rapid, simple, direct, sensitive and useful for pesticide analysis.

Pacioni, Natalia L. [Instituto de Investigaciones en Fisico Quimica de Cordoba (INFIQC), Departamento de Quimica Organica, Facultad de Ciencias Quimicas, Universidad Nacional de Cordoba, Ciudad Universitaria, 5000 Cordoba (Argentina); Veglia, Alicia V. [Instituto de Investigaciones en Fisico Quimica de Cordoba (INFIQC), Departamento de Quimica Organica, Facultad de Ciencias Quimicas, Universidad Nacional de Cordoba, Ciudad Universitaria, 5000 Cordoba (Argentina)]. E-mail: aveglia@mail.fcq.unc.edu.ar

2007-01-30

61

Determination of poorly fluorescent carbamate pesticides in water, bendiocarb and promecarb, using cyclodextrin nanocavities and related media.  

Science.gov (United States)

The effect of native cyclodextrins (alpha, beta, or gammaCD with six, seven and eight glucose units, respectively), hydroxypropyl-beta-cyclodextrin (HPCD), chitosan (CHT) and glucose in water solution or water with n-propylamine (PA) as co-solvent upon the UV-vis and fluorescence properties of poorly fluorescent N-methyl carbamates pesticides (C) as bendiocarb (2,2-dimethyl-1,3-benzodioxol-4-ol methylcarbamate, BC) and promecarb (3-methyl-5-(1-methylethyl)phenol methylcarbame, PC) was examined. Fluorescent enhancement was found for both substrates with all CDs in water or PA-water except from PC with alphaCD. The addition of CHT increases the fluorescence of BC but decreases the fluorescence of PC, and glucose addition gives in both cases no spectral changes. Host-guest interaction was clearly determined by fluorescence enhancement with betaCD and HPCD with a 1:1 stoichiometry for the complexes (C:CD). The values obtained for the association constants (K(A), M(-1)) were (6+/-2)x10(2) and (2.3+/-0.3)x10(2) for BC:betaCD and BC:HPCD complexes, respectively. For PC:betaCD and PC:HPCD the values of K(A) were (19+/-2)x10(2) and (21+/-2)x10(2), respectively. The ratio of the fluorescence quantum yields for the bound and free substrates (phi(CCD)/phi(C)) was in the range 1.74-3.8. The limits of detection (L(D), microg mL(-1)) for the best conditions were (0.57+/-0.02) for BC with HPCD and (0.091+/-0.002) for PC with betaCD in water. Application to the analysis in pesticide spiked samples of tap water and fruit yields satisfactory apparent recoveries (84-114%), and for the extraction procedure in fruits and a commercial formulation, recoveries were of 81-98% and 104%, respectively. The method is rapid, simple, direct, sensitive and useful for pesticide analysis. PMID:17386527

Pacioni, Natalia L; Veglia, Alicia V

2007-01-30

62

Determination of poorly fluorescent carbamate pesticides in water, bendiocarb and promecarb, using cyclodextrin nanocavities and related media  

International Nuclear Information System (INIS)

The effect of native cyclodextrins (?, ?, or ?CD with six, seven and eight glucose units, respectively), hydroxypropyl-?-cyclodextrin (HPCD), chitosan (CHT) and glucose in water solution or water with n-propylamine (PA) as co-solvent upon the UV-vis and fluorescence properties of poorly fluorescent N-methyl carbamates pesticides (C) as bendiocarb (2,2-dimethyl-1,3-benzodioxol-4-ol methylcarbamate, BC) and promecarb (3-methyl-5-(1-methylethyl)phenol methylcarbame, PC) was examined. Fluorescent enhancement was found for both substrates with all CDs in water or PA-water except from PC with ?CD. The addition of CHT increases the fluorescence of BC but decreases the fluorescence of PC, and glucose addition gives in both cases no spectral changes. Host-guest interaction was clearly determined by fluorescence enhancement with ?CD and HPCD with a 1:1 stoichiometry for the complexes (C:CD). The values obtained for the association constants (K A, M-1) were (6 ± 2) x 102 and (2.3 ± 0.3) x 102 for BC:?CD and BC:HPCD complexes, respectively. For PC:?CD and PC:HPCD the values of K A were (19 ± 2) x 102 and (21 ± 2) x 102, respectively. The ratio of the fluorescence quantum yields for the bound and free substrates (? CCD/? C) was in the range 1.74-3.8. The limits of detection (L D, ?g mL-1) for the best conditions were (0.57 ± 0.02) for BC with HPC57 ± 0.02) for BC with HPCD and (0.091 ± 0.002) for PC with ?CD in water. Application to the analysis in pesticide spiked samples of tap water and fruit yields satisfactory apparent recoveries (84-114%), and for the extraction procedure in fruits and a commercial formulation, recoveries were of 81-98% and 104%, respectively. The method is rapid, simple, direct, sensitive and useful for pesticide analysis

63

Cholinesterase sensors based on screen-printed electrodes for detection of organophosphorus and carbamic pesticides.  

Science.gov (United States)

Cholinesterase sensors based on screen-printed electrodes modified with polyaniline, 7,7',8,8'-tetracyanoquinodimethane (TCNQ), and Prussian blue have been developed and tested for detection of anticholinesterase pesticides in aqueous solution and in spiked grape juice. The influence of enzyme source and detection mode on biosensor performance was explored. It was shown that modification of the electrodes results in significant improvement of their analytical characteristics for pesticide determination. Thus, the slopes of the calibration curves obtained with modified electrodes were increased twofold and the detection limits of the pesticides were reduced by factors of 1.6 to 1.8 in comparison with the use of unmodified transducers. The biosensors developed make it possible to detect down to 2 x 10(-8) mol L(-1) chloropyrifos-methyl, 5 x 10(-8) mol L(-1) coumaphos, and 8 x 10(-9) mol L(-1) carbofuran in aqueous solution and grape juice. The optimal conditions for grape juice pretreatment were determined to diminish interference from the sample matrix. PMID:12942229

Ivanov, Alexey; Evtugyn, Gennady; Budnikov, Herman; Ricci, Francesco; Moscone, Danila; Palleschi, Giuseppe

2003-10-01

64

Computer-assisted design and synthesis of molecularly imprinted polymers for the simultaneous determination of six carbamate pesticides from environmental water.  

Science.gov (United States)

The computer-assisted design and synthesis of molecularly imprinted polymers for the simultaneous capture of six carbamate pesticides from environmental water are reported in this work. The quantum mechanical computational approach was employed to design the molecularly imprinted polymers with carbofuran as template. The interaction energies between the template molecule and different functional monomers in various solvents were calculated to assist in the selection of the functional monomer and porogen. The optimised molecularly imprinted polymer was subsequently used as a class-selective sorbent in solid-phase extraction for pre-concentration and determination of carbamates from environmental water. The parameters influencing the extraction efficiency of the molecularly imprinted solid-phase extraction procedure were systematically investigated to facilitate the class-selective extraction. For the proposed method, linearity was observed over the range of 2-500 ng/mL with the correlation coefficient ranging from 0.9760 to 1.000. The limits of detection ranged from 0.2 to 1.2 ng/mL, and the limit of quantification was 4 ng/mL. These results confirm that computer-assisted design is an effective evaluation tool for molecularly imprinted polymers synthesis, and that molecularly imprinted solid-phase extraction can be applied to the simultaneous analysis of carbamates in environmental water. PMID:25234239

Qi, Peipei; Wang, Xiangyun; Wang, Xinquan; Zhang, Hu; Xu, Hao; Jiang, Kezhi; Wang, Qiang

2014-10-01

65

Carbon nanotubes-reinforced hollow fibre solid-phase microextraction coupled with high performance liquid chromatography for the determination of carbamate pesticides in apples.  

Science.gov (United States)

An effective and sensitive method to determinate five carbamate pesticides in apples was developed by using carbon nanotubes-reinforced hollow fibre solid-phase microextraction (CNTs-HF-SPME) combined with high performance liquid chromatography-photodiode array detection (HPLC-DAD). The CNTs were dispersed in water via adding surfactant, and then were held in the pores of HF supported by capillary forces and sonification. The SPME device, which was wetted with 1-octanol, was placed in a stirred apple samples to extract target analytes. After extraction, analytes were desorbed and analyzed using HPLC-DAD. Under the optimized extraction conditions, the enrichment factors were achieved in the range from 49 to 308 with good inter-fibre repeatability and batch-to-batch reproducibility, while good linearity ranges and recoveries were obtained. The limits of detection ranged from 0.09 to 6.00 ng/g. Therefore, the results demonstrated that this novel method was an efficient pretreatment and enrichment procedure for the determination of trace carbamate pesticides in apples. PMID:23561102

Song, Xin-Yue; Shi, Yan-Ping; Chen, Juan

2013-08-15

66

Optimization and validation of liquid-liquid extraction with low temperature partitioning for determination of carbamates in water  

Energy Technology Data Exchange (ETDEWEB)

Using a 2{sup 3} experimental design, liquid-liquid extraction with low temperature partitioning (LLE-LTP) was optimized and validated for analysis of three carbamates (aldicarb, carbofuran and carbaryl) in water samples. In this method, 2.0 mL of sample is placed in contact with 4.0 mL of acetonitrile. After agitation, the sample is placed in a freezer for 3 h for phase separation. The organic extract is analyzed by high performance liquid chromatography with ultraviolet detection (HPLC-UV). For validation of the technique, the following figures of merit were evaluated: accuracy, precision, detection and quantification limits, linearity, sensibility and selectivity. Extraction recovery percentages of the carbamates aldicarb, carbofuran and carbaryl were 90%, 95% and 96%, respectively. Even though extremely low volumes of sample and solvent were used, the extraction method was selective and the detection and quantification limits were between 5.0 and 10.0 {mu}g L{sup -1}, and 17.0 and 33.0 {mu}g L{sup -1}, respectively.

Machado Goulart, Simone; Domingos Alves, Renata; Neves, Antonio Augusto; Queiroz, Jose Humberto de; Conde de Assis, Tamires [Departamento de Quimica, Universidade Federal de Vicosa, Vila Gianetti, Casa 24, 36 570-000 Vicosa, MG (Brazil); Queiroz, Maria Eliana L.R. de, E-mail: meliana@ufv.br [Departamento de Quimica, Universidade Federal de Vicosa, Vila Gianetti, Casa 24, 36 570-000 Vicosa, MG (Brazil)

2010-06-25

67

Optimization and validation of liquid-liquid extraction with low temperature partitioning for determination of carbamates in water  

International Nuclear Information System (INIS)

Using a 23 experimental design, liquid-liquid extraction with low temperature partitioning (LLE-LTP) was optimized and validated for analysis of three carbamates (aldicarb, carbofuran and carbaryl) in water samples. In this method, 2.0 mL of sample is placed in contact with 4.0 mL of acetonitrile. After agitation, the sample is placed in a freezer for 3 h for phase separation. The organic extract is analyzed by high performance liquid chromatography with ultraviolet detection (HPLC-UV). For validation of the technique, the following figures of merit were evaluated: accuracy, precision, detection and quantification limits, linearity, sensibility and selectivity. Extraction recovery percentages of the carbamates aldicarb, carbofuran and carbaryl were 90%, 95% and 96%, respectively. Even though extremely low volumes of sample and solvent were used, the extraction method was selective and the detection and quantification limits were between 5.0 and 10.0 ?g L-1, and 17.0 and 33.0 ?g L-1, respectively.

68

Development of an improved single-drop microextraction method and its application for the analysis of carbamate and organophosphorus pesticides in water samples.  

Science.gov (United States)

An improved single-drop microextraction (SDME) method combined with high performance liquid chromatography has been developed for the detection of trace carbamate and organophosphorus pesticides in water samples. The most fascinating feature of the proposed method is the use of an oval-shaped polychloroprene rubber (PCR) tube to load the extraction solvent, which efficiently loads more solvent and improves the stability of extraction microdrop. Furthermore, this device provides a larger contact surface between the extraction solvent and the inner surface of the oval-shaped PCR tube than that between the extraction solvent and the tip of a microsyringe needle in the conventional SDME. It thereby avoids the problem of the drop floating upwards or dislodging from the tip of the microsyringe needle as observed in the traditional SDME. This method is significant for the great improvement it can offer in extraction efficiency. A series of extraction parameters were investigated systematically using carbamate and organophosphorus as the model analytes. Under the optimal conditions, the enrichment factors for analysis were between 117 and 177, and the limits of detection were ?0.63 ?g L(-1) (S/N = 3). The repeatability study was carried out by extracting the spiked water samples. Here the relative standard deviations varied between 4.0 and 5.8% (n = 5). Additionally, the proposed method was successfully applied to the determination of pesticides in real water samples, and good recoveries were obtained from 79% to 112%. The proposed method was demonstrated to hold advantages of low cost, simplicity of operation, and successful application to in real water samples. PMID:23013769

Wang, Xiuhong; Cheng, Jing; Wang, Xiangfang; Wu, Min; Cheng, Min

2012-11-21

69

Organophosphate and carbamate poisoning.  

Science.gov (United States)

Organophosphates (OPs) and carbamates have a wide variety of applications, most commonly as pesticides used to eradicate agricultural pests or control populations of disease-carrying vectors. Some OP and carbamates have therapeutic indications such as physostigmine. Certain organophosphorus compounds, known as nerve agents, have been employed in chemical warfare and terrorism incidents. Both classes inhibit acetylcholinesterase (AChE) enzymes, leading to excess acetylcholine accumulation at nerve terminals. In the setting of toxicity from either agent class, clinical syndromes result from excessive nicotinic and muscarinic neurostimulation. The toxic effects from OPs and carbamates differ with respect to reversibility, subacute, and chronic effects. Decontamination, meticulous supportive care, aggressive antimuscarinic therapy, seizure control, and administration of oximes are cornerstones of management. PMID:25455666

King, Andrew M; Aaron, Cynthia K

2015-02-01

70

Organophosphorus and carbamate pesticide exposure in Putumayo Province, Colombia Factores de exposición a plaguicidas organofosforados y carbamatos en el departamento del Putumayo, 2006  

Directory of Open Access Journals (Sweden)

Full Text Available Introduction. In 2005, the Sistema de Vigilancia en Salud Pública, the governmental agency responsible for monitoring public health, found that Putumayo Province has the highest incidence of poisoning by pesticides in Colombia.
Objective. Exposure to organophosphorus and carbamate pesticides and carbamates was established in the agricultural population of Putumayo by determining acetylcholinesterase levels.
Materials and methods. A cross-sectional survey was made in 204 occupationally exposed workers in four municipalities of Putumayo. A questionnaire was administered to collect subject information; a blood sample was taken for acetylcholinesterase determination by Michel's method. A straightforward analysis of the variables and possible associations were explored. A group of workers was enabled with SARAR (a participative educational strategy that means: S: safety, A: association, R: reaction, A: actualization and R: responsabilitymethodology for use and handling of pesticides.
Results. The average time of exposure was nine years. Seventy-five percent declared using extremely toxic pesticides and 13% highly toxic. On average, they applied pesticides 7.3 hours/day. Nearly 10% used organochloride pesticides. Furthermore, 17.6% demonstrated inhibition of the enzyme acetylcholinesterase.
Conclusion. A realistic scale of the pesticide use problem in humans was obtained; and the data effectively recommend an educatiional intervention for the workers and their families with SARAR methodology.Introducción. En 2005 el Sistema de Vigilancia en Salud Pública encontró que el departamento del Putumayo es la región con mayor incidencia de intoxicaciones por plaguicidas en Colombia.
Objetivo. Establecer la exposición a plaguicidas organofosforados y carbamatos en la población agrícola mediante la determinación de los niveles de acetilcolinesterasa en el departamento
de Putumayo, utilizando el método de Michel.
Materiales y métodos. Se realizó un estudio transversal en 204 trabajadores ocupacionalmente expuestos, en cuatro municipios del departamento de Putumayo. Se aplicó una encuesta para recolectar información y se tomó una muestra de sangre para la determinación de la acetilcolinesterasa. Se llevó a cabo el análisis simple de las variables y se exploraron posibles asociaciones. Un grupo de trabajadores fueron capacitados con la metodología SARAR (una estrategia educacional participativa que significa: S: seguridad, A: asociación, R: reacción, A: actualización y R: responsabilidad sobre el uso y el manejo de plaguicidas.
Resultados. Se estableció que el tiempo promedio de exposición fue de nueve años. El 75,2% manifestó emplear plaguicidas extremadamente tóxicos y el 13,0% altamente tóxicos. En promedio refirieron aplicar plaguicidas 7,3 horas al día. El 9,8% usaban plaguicidas organoclorados. En cuanto a la actividad de la enzima acetilcolinesterasa, 17,6% presentaban inhibición.
Conclusión. Este trabajo permitió tener una dimensión real del problema de los plaguicidas en el Putumayo y utilizarla para hacer una intervención educativa sobre los trabajadores y sus familias, con la metodología SARAR.

Marcela Varona

2007-09-01

71

[Determination of N-methyl carbamate pesticides in diet samples by high performance liquid chromatography-linear ion trap mass spectrometry with gel permeation chromatography cleanup].  

Science.gov (United States)

A method for the determination of N-methyl carbamate (NMC) pesticides in diet samples was developed by high performance liquid chromatography-linear ion trap mass spectrometry (HPLC-LIT-MS). The samples with the isotope internal standard were ultrasonically extracted with acetonitrile saturated with cyclohexane, and then cleaned-up by passing through gel permeation chromatographic (GPC) column. The LC separation was performed on a CAPCELL PAK CR column (100 mm x 2.1 mm, 5 microm; SCX-C18 (1 : 4)) using acetonitrile and 5 mmol/L ammonium formate/0.1% (v/v) formic acid aqueous solution as mobile phases (gradient elution) at a flow rate of 0.2 mL/min. The ionization of the analytes was performed by positive electrospray mode. Selective reaction monitoring (SRM) was used for the monitoring of MS3 transitions for each compound. The internal standard was used for quantitation. The average recoveries were in the range of 60.4% - 114%, and the relative standard deviations (RSDs) were all not more than 16.2%. The limits of detection (LODs) were 0.001-0.010 mg/kg. The method was successfully applied to the determination of 15 compounds of interest in nine foodstuffs from the fourth Chinese Total Diet Study (TDS) performed in 2007, and aldicarb and carbofuran were found in several samples. PMID:25185310

Yang, Xin; Li, Peng; Miao, Hong; Zhao, Yunfeng; Wu, Yongning

2014-05-01

72

INTERLABORATORY STUDY OF A THERMOSPRAY-LIQUID CHROMATOGRAPHIC/MASS SPECTROMETRIC METHOD FOR SELECTED N-METHYL CARBAMATES, N-METHYL CARBAMOYLOXIMES, AND SUBSTITUTED UREA PESTICIDES  

Science.gov (United States)

A thermospray-liquid chromatographic/mass spectrometric (TS-LC/MS) method was evaluated in an interlaboratory study for determining 3 N-methyl carbamates (bendiocarb, carbaryl, and carbofuran), 3-N-methyl carbamoyloximes (aldicarb, methomyl, and oxamyl), 2 substituted urea pestic...

73

Pesticides  

Science.gov (United States)

... yourself and your family from pesticides on non-organic fruits and vegetables, remove the outer leaves of leafy vegetables and ... mixed with salt and lemon juice or vinegar. Organic growers do ... vegetables. HOME SAFETY AND PESTICIDES When using pesticides at ...

74

Principles of Single-Laboratory Validation of Analytical Methods for Testing the Chemical Composition of Pesticides  

International Nuclear Information System (INIS)

Underlying theoretical and practical approaches towards pesticide formulation analysis are discussed, i.e. general principles, performance characteristics, applicability of validation data, verification of method performance, and adaptation of validated methods by other laboratories. The principles of single laboratory validation of analytical methods for testing the chemical composition of pesticides are outlined. Also the theoretical background is described for performing pesticide formulation analysis as outlined in ISO, CIPAC/AOAC and IUPAC guidelines, including methodological characteristics such as specificity, selectivity, linearity, accuracy, trueness, precision and bias. Appendices I–III hereof give practical and elaborated examples on how to use the Horwitz approach and formulae for estimating the target standard deviation towards acceptable analytical repeatability. The estimation of trueness and the establishment of typical within-laboratory reproducibility are treated in greater detail by means of worked-out examples. (author)

75

Validation of the PESTLA model: evaluation of the validation statuses of the pesticide leaching models PRZM-1, LEACHP, GLEAMS, and PELMO  

OpenAIRE

The validation statuses of the pesticide leaching models PRZM-1, LEACHP, GLEAMS and PELMO were assessed by literature study. The required range of validity included all the situations in which pesticides are applied in Dutch agriculture and horticulture. The models should predict pesticide leaching to groundwater at concentration levels of some 0.1 Šg/l based on laboratory-measured sorption and transformation rate parameters. All the available model tests were reviewed and their soundness an...

Bosch, H.; Boesten, J. J. T. I.

1995-01-01

76

Guidelines for the validation of qualitative multi-residue methods used to detect pesticides in food  

OpenAIRE

There is a current trend for many laboratories to develop and use qualitative gas chromatography–mass spectrometry (GC-MS) and liquid chromatography-mass spectrometry (LC-MS) based multi-residue methods (MRMs) in order to greatly increase the number of pesticides that they can target. Before these qualitative MRMs can be used for the monitoring of pesticide residues in food, their fitness-for-purpose needs to be established by initial method validation. This paper sets out to assess the per...

Mol, J. G. J.; Reynolds, S. L.; Fussell, R. J.; Stajnbaher, D.

2012-01-01

77

Validation of a residue method to determine pesticide residues in cucumber by using nuclear techniques  

International Nuclear Information System (INIS)

In this study, a multi-residue method using ethyl acetate for extraction and gel permeation chromatography for clean-up was validated to determine chlorpyrifos, malathion and dichlorvos in cucumber by gas chromatography. For this purpose, homogenized cucumber samples were fortified with pesticides at 0.02 0.2, 0.8 and 1 mg/kg levels. The efficiency and repeatability of the method in extraction and cleanup steps were performed using 14C-carbaryl by radioisotope tracer technique. 14C-carbaryl recoveries after the extraction and cleanup steps were between 92.63-111.73 % with a repeatability of 4.85% (CV) and 74.83-102.22 % with a repeatability of 7.19% (CV), respectively. The homogeneity of analytical samples and the stability of pesticides during homogenization were determined using radio tracer technique and chromatographic methods, respectively.

78

Development and validation of a multiresidue method for determination of 37 pesticides in soil using GC-NPD.  

Science.gov (United States)

In this study, a multiresidue analytical method for the detection of 37 pesticides in a soil matrix was developed and validated. The soil sample was fortified with a known quantity of pesticides at two different concentration levels (0.1 and 0.01?µg/g) and the analytes were extracted via a liquid-solid extraction method. The pesticides were separated on an HP5 capillary column and were analyzed with a gas chromatograph coupled to a nitrogen-phosphorous detector (GC-NPD). Method validation was accomplished with good linearity (r(2) = 0.994-0.999) within a considerable range of concentrations. Satisfactory recoveries (70.5-110.4%) were obtained with 32 pesticides at both spiking concentration levels, whereas five pesticides-dimepiperate, buprofezin, prometryn, pirimicarb, and fludioxonil-were recovered at relatively low levels (43.6-61.8%). The applicability of the method was demonstrated by analyzing field samples collected from 24 different sites around Yeongsan and Sumjin rivers in the Republic of Korea. No residues of the selected pesticides were detected in any of the samples. The developed method could be employed as a simple and cost-effective method for the routine detection and analysis of 37 pesticides in soil samples. PMID:21154886

Park, Jong Hyouk; Mamun, Md Iqbal Rouf; Abd El-Aty, A M; Na, Tae Woong; Choi, Jeong-Heui; Ghafar, M W; Kim, Kap Soon; Kim, Sang Don; Shim, Jae-Han

2011-09-01

79

Investigation of pesticide residues in apple fruits from conventional and integrated pest management  

OpenAIRE

Abstract This study describes method validation for determination of more than 40 pesticides in apples using GC technique. Target compounds belong to the groups of organochlorine, organophosphorus, carbamates, pyrethroids, triazoles, dicarboximides, strobilurins etc. The sample preparation consists of acetone extraction and subsequent cleanup/concentration by SPE with polymer-based sorbent. Single quadrupole GC-MS operating in SIM mode and electron impact ionization was used for id...

2009-01-01

80

Adaptation and validation of the TLC detection methods in determination of pesticide residues in grain  

International Nuclear Information System (INIS)

This work was performed to investigate the possibilities of applying prescribed TLC detection methods in combination with GPC cleanup procedure in grains as alternative methods to gas and high performance liquid chromatography for pesticide residue analyses. The MDQ, RF and RRf values of marker and selected compounds were close to those reported in the basic method. The recoveries and reproducibility of the method obtained with wheat and rice samples in our laboratory were within the limits specified by the Codex GLs on method validation. The recoveries determined by GC analyses were practically the same which confirms the accuracy of TLC detection. (author)

81

Estudio epidemiológico de exposición a plaguicidas organofosforados y carbamatos en siete departamentos colombianos, 1998-2001 / Epidemiological study of organophosphate and carbamate pesticide exposure in 7 separated zones in Colombia  

Scientific Electronic Library Online (English)

Full Text Available SciELO Colombia | Language: Spanish Abstract in spanish Objetivo. Determinar la actividad de la acetilcolineterasa en trabajadores con riesgo de exposición a plaguicidas organofosforados y carbamatos y los plaguicidas más frecuentemente aplicados en los cultivos agrícolas en siete departamentos colombianos durante el período de 1998 a 2001. Material y mé [...] todos. De 1998 a 2001, participaron las entidades territoriales de salud de Boyacá, Caldas, Huila, Meta, Norte de Santander, Santander y Valle del Cauca, con 25.242 trabajadores a quienes se les realizó la determinación de la actividad de la acetilcolinesterasa como biomarcador de exposición a estos plaguicidas mediante el método de Limperos y Ranta modificado por Edson. Resultados. Del total de trabajadores, el 78,9% eran hombres y 21,1% mujeres; el 38,8% se encontraba en un rango de edad de 26 a 40 años. El 66,1% reportó pertenecer a un régimen de seguridad social; los oficios con mayor número de trabajadores fueron: fumigador-aplicador con 39,1% y jornalero con 24,9%. Se realizaron 25.356 pruebas de acetilcolinesterasa, de las cuales, 7,6% mostraron resultados anormales. Conclusiones. Con relación a los plaguicidas de importancia en salud pública más usados, se encontraron los organofosforados con 42,4% seguido por carbamatos con 17,8%, insecticidas organoclorados con 8,4% y clorinados 6,6%, lo cual hace necesario ampliar el uso de biomarcadores para la vigilancia de trabajadores expuestos a plaguicidas no controlados por el programa. Abstract in english Objective. Acetylcholinesterase activity was measured in workers potentially exposed to pesticides that are frequently used in agriculture in 7 provinces in Colombia between 1998and 2001. Material and methods. During this period, local health centers in the Departments (provinces) of Boyacá, Caldas, [...] Huila, Meta, Norte de Santander, Santander and Valle del Cauca monitored a total of 25,242 workers for acetylcholinesterase activity. The Limperos and Ranta method, modified by Edson, was used to detect levels of pesticide exposure. Results. The worker sample consisted of 78.9% men and 21.1% women. Thirty-nine percent of the workers were between 26 and 40 years of age, and 66% had social security. The most common work activities were use of spray applicators (39.1%) and harvesters (24.9%). Of the 25,356 tests for acetylcholinesterase activity, 7.6% showed abnormal activity levels. Conclusion. In the zones investigated, organophosphosphates were the most commonly used pesticides (42.4%), followed by carbamates (17.8%), organochlorines (8.4%) and chlorinates (6.6%). The diversity of pesticides in use underlines the need to increase the variety of biomarkers for monitoring exposed workers.

Omayda, Cárdenas; Elizabeth, Silva; Ligia, Morales; Jaime, Ortiz.

2005-06-01

82

Development, validation and determination of multiclass pesticide residues in cocoa beans using gas chromatography and liquid chromatography tandem mass spectrometry.  

Science.gov (United States)

An efficient and rapid method for the analysis of pesticide residues in cocoa beans using gas and liquid chromatography-tandem mass spectrometry was developed, validated and applied to imported and domestic cocoa beans samples collected over 2 years from smallholders and Malaysian ports. The method was based on solvent extraction method and covers 26 pesticides (insecticides, fungicides, and herbicides) of different chemical classes. The recoveries for all pesticides at 10 and 50 ?g/kg were in the range of 70-120% with relative standard deviations of less than 20%. Good selectivity and sensitivity were obtained with method limit of quantification of 10 ?g/kg. The expanded uncertainty measurements were in the range of 4-25%. Finally, the proposed method was successfully applied for the routine analysis of pesticide residues in cocoa beans via a monitoring study where 10% of them was found positive for chlorpyrifos, ametryn and metalaxyl. PMID:25442595

Zainudin, Badrul Hisyam; Salleh, Salsazali; Mohamed, Rahmat; Yap, Ken Choy; Muhamad, Halimah

2015-04-01

83

(BOSC) DOSE-RESPONSE MODELING FOR THE ASSESSMENT OF CUMULATIVE RISK DUE TO EXPOSURE TO N-METHYL CARBAMATE PRESTICIDES  

Science.gov (United States)

THE US EPA'S N-METHYL CARBAMATE CUMULATIVE RISK ASSESSMENT (NMCRA) ASSESSES THE EFFECT ON ACETYLCHOLINE ESTERASE (AChE) ACTIVITY OF EXPOSURE TO 10 N-METHLY CARBAMATE (NMC)PESTICIDES THROUGH DIETARY, DRINKING WATER, AND RESIDENTIAL EXPOSURES. THESE DATA THUS INFORM, BUT DO NOT COM...

84

Data-derived uncertainty factor approach in the revised N-methyl carbamate risk assessment.  

Science.gov (United States)

EPA completed its Revised Cumulative Risk Assessment (CRA) of the N-methyl Carbamate (NMC) Pesticides in 2007. This assessment evaluated the joint risk to 10 pesticides from food, water, and residential exposure. NMCs share the ability to inhibit acetylcholinesterase (AChE) via c...

85

Validation of thin-layer chromatographic methods for pesticide residue analysis. Results of the coordinated research projects 1996-2002  

International Nuclear Information System (INIS)

Thin-layer chromatography (TLC) has a long history, but has been used only to a limited extent in pesticide residue analytical laboratories since gas liquid chromatography (GLC) and high performance liquid chromatography (HPLC) became readily available. Recent developments in the quality of plate coating and detection systems, as well as in extraction and cleanup methods have revived interest in TLC. The combination of these procedures with rigid quality control has created a niche for TLC in laboratories working in compliance with ISO 17025 or GLP. The Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture recognized the importance of testing pesticide residues, especially in countries with limited resources. A coordinated research programme (CRP) was initiated for investigating the application of TLC detection methods to complement the instrumental techniques in pesticide residue analysis. An initial technical contract provided proof of the concept and elaborated the basic procedures, including a substantial database of retention factors and minimum detectable quantities of pesticides. To satisfy the demands from the eligible laboratories, two similar projects were started in 1997 and 1998. The titles of the projects were as follows: (i) Validation of Thin-layer Chromatographic Screening Methods for Pesticide Residue Analysis; and (ii) Alternative Methods to Gas and High Performance Liquid Chromatography for Pesticide Residue Analysis in Grain. Scientists from 18 countries participated in the above noted two projects. The major tasks of this programme were to adapt the methods, check the repeatability and reproducibility of Rf values, the minimum detectable quantities (MDQ) and apply the methods for determining various pesticide residues in representative matrices. Furthermore, they have extended the methods to other pesticides and commodities of interest in their countries and validated the methods elaborated. This TECDOC includes the most important results of the CRPs. The Rf and MDQ values reported by the participating scientists are compiled in one table for facilitating the assessment of the repeatability and reproducibility of the results. Since the participants were applying the same basic methodology, described in detail in the first article, these methods are only referred to in the other papers. However, the modifications made by the participants are described in their papers. The purpose of this TECDOC is to provide the readers with comprehensive information on the application of TLC detection methods to complement the instrumental techniques in pesticide residue analysis. Further information on any specific topic may be obtained from the authors

86

METABOLISM OF CARBAMATE INSECTICIDES  

Science.gov (United States)

The results of studies conducted to determine the metabolic fate of carbamate insecticides and its toxicological significance are presented. Methomyl metabolism in rats was investigated in detail as was Croneton in the rat, cow, pig and chicken. Carbaryl and carbofuran were admin...

87

Analytical Method Validation of Selected Organochlorine Pesticides in Fortified Rice Using Gas Chromatography with Electron Capture Detector  

Directory of Open Access Journals (Sweden)

Full Text Available Gas chromatography with electron capture detector (GC-ECD has been validated for simultaneous determination of selected organochlorine pesticides namely heptachlor, endosulfan, dieldrin, dan p,p’-dichlorodiphenyltrichloroethane (p,p’-DDT using aldrin as standard internal. Some parameters for analytical method validation were evaluated, i.e. linearity, precision, sensitivity expressed with limit of detection and limit of quantification, and recovery. GC-ECD was linear for determination of these pesticides with r values ? 0.99. The values of LOD obtained were 2.50, 2.97, 1.61, and 2.54 ng/mL for heptachlor, endosulphan, dieldrin, and p,p’-DDT, respectively. Furthermore, the relative standard deviation (RSD values obtained for the assessment of analytical precision were lower than those required by Horwitz. Finally, the used GC-ECD method was accurate for determination of these organochlorine psticides in fortified rice samples which were indicated by the acceptable recovery percentages.

Mutia Kusuma Wardani

2014-01-01

88

Generalisering og validering af model for afdrift af pesticider til læhegn og andre marknære biotoper  

DEFF Research Database (Denmark)

I det netop afsluttede projekt ”Generalisering og validering af model for sprøjtemiddelafdrift til læhegn og andre marknære biotoper” har vi målt, hvor meget af det sprøjtemiddel, landmanden sprøjter ud, der ender i markens læhegn. Målingerne er anvendt til at videreudvikle og validere en model, der kan forudsige afdriften af de fleste sprøjtemidler under forskellige betingelser. Modellen kan tage hensyn til de givne egenskaber for pesticidet og til dysens dråbestørrelser, hvordan vejret er og om der er en sprøjtefri zone mellem traktoren og naturen uden for marken. Desuden kan modellen differentiere mellem forskellige højder i læhegn. Som forventet var afdriften til læhegn mindre ved brug af en luftinjektions-dyse end ved sprøjtning med fladsprede-dyse i den samme mark. Forskellen i afdrift mellem de to typer af dyser viser, at der er potentiale for, via valg af sprøjteudstyr, at reducere mængden af pesticider, der lander i læhegnene og dermed reducerer blomstring og frugtsætning. Samtidig viser såvel målinger som modelberegninger, at der ikke er den store effekt af sprøjtefrie bufferzoner på afdriften til læhegn, specielt ikke i den øverste del af læhegnene, hvor frugterne ofte er mest talrige.

Bruus, Marianne; LØfstrØm, Per

2014-01-01

89

Carbamate and Organophosphorus Nematicides: Acetylcholinesterase inhibition and Effects on Dispersal  

OpenAIRE

The sensitivities of acetylcholinesterases (ACHE) from the fungus-feeder Aphelenchus avenae and the plant-parasitic species Helicotylenchus dihystera and Pratylenchus penetrans and the housefly, Musca domestica, were compared using a radiometric assay which utilized H³ acetylcholine as a substrate. Nematode ACHE were generally less sensitive to inhibition by organophosphorns and carbamate pesticides than were ACHE from the housefly. ACHE from the plant-parasitic species and A. avenae were ge...

Pree, D. J.; Townshend, J. L.; Archibald, D. E.

1989-01-01

90

Validation and Uncertainty of the method for multiresidue analysis of 35 pesticides in melon using Gas Chromatography Coupled to Quadrupole Mass Spectrometry (GC-QP/MS)  

Science.gov (United States)

QuEChERS method and detection in GC/SQ-MS were validated for the analysis of 35 pesticides in melon. Validation parameters (selectivity, linearity, LOD, LOQ, accuracy and precision) were determined according ABNT NBR 14029:2005. The recoveries rates for all the pesticides studied were from 63% to 117% with relative standard deviation (RSD) lower than 15% in the concentration range of 0.05 – 0.20 mg/kg. The limit of quantification (LOQ) for most compounds were below the MRLs established in Brazil. The combined relative uncertainty (Uc) and expanded uncertainty (Ue) was determined using repetitivity, recovery and calibration curves data for each pesticide.

Milhome, M. A. L.; Sousa, J. S.; Andrade, G. A.; de Castro, R. C.; Lima, L. K.; Lima, C. G.; Nascimento, R. F.

2015-01-01

91

USE OF EXPOSURE-RELATED DOSE ESTIMATING MODEL (ERDEM) FOR ASSESSMENT OF AGGREGATE EXPOSURE OF INFANT AND CHILDREN TO N-METHYL CARBAMATE INSECTICIDES  

Science.gov (United States)

A physiologically based pharmacokinetic (PBPK) model was developed within the Exposure Related Dose Estimating Model (ERDEM) framework to investigate selected exposure inputs related to recognized exposure scenarios of infants and children to N-methyl carbamate pesticides as spec...

92

Thin Layer Chromatography of Pesticides and Their Residues  

Directory of Open Access Journals (Sweden)

Full Text Available Recent progress in the analysis of organo-phosphorus, organo-chlorine, carbamate, urea, uracil pesticides and their residues by thin layer chromatorgraphic methods employing chemical and enzymatic methods is reviewed.

S. P. Katrolia

2014-03-01

93

Validation of Analysis Method of pesticides in fresh tomatoes by Gas Chromatography associated to a liquid scintillation counting  

International Nuclear Information System (INIS)

Pesticides are nowadays considered as toxic for human health. The maximum residues levels (MRL) in foodstuff are more and more strict. Therefore, selective analytical techniques are necessary for their identification and their quantification. The aim of this study is to set up a multi residue method for the determination of pesticides in tomatoes by gas chromatography with ?ECD detector (GC/?ECD) associated to liquid scintillation counting. A global analytical protocol consisting of a QuECHERS version of the extraction step followed by purification step of the resulting extract on a polymeric sorbent was set up. The 14C-chloropyrifos used as an internal standard proved excellent to control the different steps needed for the sample preparation. The method optimized is specific, selective with a recovery averaged more than 70 pour cent, repetitive and reproducible. Although some others criteria need to be checked regarding validation before its use in routine analysis, the potential of the method has been demonstrated.

94

Validation of a methodology multi-residue for the determination of pesticides residuals in strawberry (fragraria spp.) by gas chromatography  

International Nuclear Information System (INIS)

This study describes the validation of multi-residue analytical methodology for the simultaneous determination of 19 organ chlorine, organophosphorus and organ nitrogen pesticides in strawberry. Pesticides residues were extracted from strawberry samples with ethyl acetate, the extracts were cleaned-up by GPC, the quantitative analysis was carried out by high resolution gas chromatography (GC) with a pulsed splitless injection mode and simultaneous detection by m-ECD and NPD coupled in parallel. The methodology is specific, selective, and accurate and robust the calibration curves in matrix matched analytical standards show linearity over the concentration range of 0.04-5.00 mg/kg with limits of detection and quantitation between 0.007-0.5 mg/kg and 0.01-1.00 mg/kg respectively. The recovery experiments yielding averages between 80-110% for most of the pesticides. The distribution of analyze in the laboratory sample was evaluated and it was found its homogeneity. The methodology was applied in field samples and was mainly found Captan residues below MRL

95

COMPARISON OF ACUTE NEUROBEHAVIORAL AND CHOLINESTERASE INHIBITORY EFFECTS OF N-METHYL CARBAMATES IN RAT  

Science.gov (United States)

There are few studies evaluating direct functional and biochemical consequences of exposure. In the present study of the acute toxicity of seven N-methyl carbamate pesticides, we evaluated the dose-response profiles of cholinesterase (ChE) inhibition in brain and erythrocytes (R...

96

Impact of Chemical Proportions on the Acute Neurotoxicity of a Mixture of Seven Carbamates in Rats  

Science.gov (United States)

Environmental exposures generally involve multiple chemicals and pathways, and statistical methodologies now exist to evaluate interactions among any number of chemicals in defined mixtures. N-methyl carbamate pesticides are presumed to act through a common mode of action, that i...

97

Pesticide Use and Self-Reported Symptoms of Acute Pesticide Poisoning among Aquatic Farmers in Phnom Penh, Cambodia  

OpenAIRE

Organophosphates and carbamates (OPs/CMs) are known for their acetylcholinesterase inhibiting character. A cross-sectional study of pesticide handling practices and self-perceived symptoms of acute pesticide poisoning was conducted using questionnaire-based interviews with 89 pesticide sprayers in Boeung Cheung Ek (BCE) Lake, Phnom Penh, Cambodia. The study showed that 50% of the pesticides used belonged to WHO class I + II and personal protection among the farmers were inadequate. A majority...

Anders Dalsgaard; Amp Rgen Holm Petersen, J.; Amp Rs, Erik J.; Flemming Konradsen; Hanne Klith Jensen

2011-01-01

98

Development and validation of a basin scale model PCPF-1@SWAT for simulating fate and transport of rice pesticides  

Science.gov (United States)

The objective of this study was to develop, verify, and validate a new GIS-based model for simulating the fate and transport of rice pesticides in river basins. A plot scale model simulating pesticide fate and transport in rice paddies (PCPF-1) was incorporated into the Soil and Water Assessment Tool (SWAT) basin scale water and pollutant transport model. The new combined model, PCPF-1@SWAT model, was first used on some base-case scenarios to verify that the PCPF-1 algorithm and the routing of variables were correctly implemented. Next, the PCPF-1@SWAT model was calibrated and validated on the Sakura River basin (Ibaraki prefecture, Japan) using mefenacet concentrations measured during the rice growing season in 2008. The modeling procedures for simulating pesticide fate and transport in a Japanese river basin were demonstrated by providing model parameters related to hydrology, land use, pesticide fate, and rice field managements methods. The water flows predicted by the PCPF-1@SWAT model in the Sakura River basin were accurate throughout the whole simulation year, with R2 and ENS statistics exceeding 0.74 and 0.71, respectively for daily flow. The use of different seepage rates had appreciable influence on the simulations. High seepage rates gave a slight overestimation of the predicted base flow during the rice growing period, whereas the base flow predictions using lower seepage rates were comparable to measured data. The PCPF-1@SWAT model successfully simulated the fate and transport of mefenacet in the Sakura River in which measured mefenacet concentrations peaked soon after the initial herbicide application in May, and decreased gradually during the months of June and July. Occasional major precipitation events caused the mefenacet concentration in streams to peak quickly due to a corresponding loss of mefenacet from paddy areas, and then rapidly decrease due to dilution by excess rainfall discharge. The simulation using a seepage rate of 0.12 cm day-1 had the most accurate prediction of mefenacet concentration in river water with an R2 of 0.61 and an ENS of 0.65.

Boulange, Julien; Watanabe, Hirozumi; Inao, Keiya; Iwafune, Takashi; Zhang, Minghua; Luo, Yuzhou; Arnold, Jeff

2014-09-01

99

Validation of thin lay chromatographic screening methods for pesticide residue analysis  

International Nuclear Information System (INIS)

Thin layer chromatographic (TLC) separation and detection methods were tested as a cost efficient alternative for identification and quantitative determination of numerous pesticide residues. Over 80% reproducibility was obtained for Rf and MDQ values compared to those previously reported. The applicability of the methods resulted in recovery values between 75 and 100%. The sample load up to 600 mg sample equivalent did not affect the Rf values significantly. (author)

100

The Enhanced Carbamate Adsorption of Modified Bentonite with Coscinium  

Directory of Open Access Journals (Sweden)

Full Text Available Pesticides daily pollutes soil and water in farmland and environment in ASEAN agricultural developing countries. In this study, pesticide adsorption was studied by bentonite modification, targeting the “organoclay” adsorbent in comparison to native bentonite, which was probably reported to adsorb agricultural pesticide. Commercial bentonite was modified with the berberine containing natural extract from Coscinium fenestratum; the local folk medicine in Thailand. The modified clay by extracted berberine was able to adsorb carbamate pesticide carbaryl with significant rate. HPLC analysis of residue carbaryl after adsorption process showed that it was up to 80% carbaryl adsorption when bentonite was modified by extracted berberine with ratio 1:100 (w/w, whereas commercial bentonite has showed at 70%. Modified bentonite by C. fenestratum extract and berberine revealed by scanning electron microscopy showed that the different transform levels of this clay surface, herein, the highest carbaryl adsorption occurred when berberine/bentonite ratio for modification process was 1/200 (w/w. SEM results also demonstrated that the amount of berberine should be taken into consideration in term of bentonite modification for pesticide adsorption. Coscinium fenestratum plant will be further studied for its contribution to pesticide adsorption material in Thailand.

S. Tha-in

2013-08-01

101

Anti-androgenic activities of environmental pesticides in the MDA-kb2 reporter cell line.  

OpenAIRE

Pesticides have been suspected to act as endocrine disruptive compounds (EDCs) through several mechanisms of action, however data are still needed for a number of currently used pesticides. In the present study, 30 environmental pesticides selected from different chemical classes (azole, carbamate, dicarboximide, oganochlorine, organophosphorus, oxadiazole, phenylureas, pyrazole, pyrimidine, pyrethroid and sulfonylureas) were tested for their ability to alter in vitro the transcriptional acti...

Ai?t-ai?ssa, S.; Laskowski, S.; Laville, N.; Porcher, J. -m; Brion, F.

2010-01-01

102

Health risks of employees working in pesticide retail shops: An exploratory study  

OpenAIRE

Background: Shop keepers dealing with pesticides are exposed to multiple pesticides that include organophosphates, organochlorines, carbamates, pyrethroids. Hence an exploratory health study was conducted on shopkeepers selling pesticides in urban areas of Lucknow and Barabanki District, Uttar Pradesh, India. Materials and Methods: Detailed information regarding socio-economic status, family history, personal habits and work practices were recorded for 20 subjects and control...

Kesavachandran C; Pathak M; Fareed M; Bihari V; Mathur N; Srivastava A

2009-01-01

103

Application and validation of approaches for the predictive hazard assessment of realistic pesticide mixtures.  

Science.gov (United States)

In freshwater systems located in agricultural areas, organisms are exposed to a multitude of toxicologically and structurally different pesticides. For regulatory purposes it is of major importance whether the combined hazard of these substances can be predictively assessed from the single substance toxicity. For artificially designed multi-component mixtures, it has been shown that the mixture toxicity can be predicted by concentration addition (CA) in case of similarly acting substances and by independent action (IA), if mixtures are composed of dissimilarly acting substances. This study aimed to analyse whether these concepts may also be used to predictively assess the toxicity of environmentally realistic mixtures. For this purpose a mixture of 25 pesticides, which reflects a realistic exposure scenario in field run-off water, was studied for its effects on the reproduction of the freshwater alga Scenedesmus vacuolatus. The toxicity of the tested mixtures showed a good predictability by CA. This is consistent with the finding that the toxicity was dominated by a group of similarly acting photosystem II inhibitors, although the mixture included substances with diverse and partly unknown mechanisms of action. IA slightly underestimated the actual mixture toxicity. However, the EC(50) values that can be derived from each prediction, according to CA respectively IA, only differed by a factor of 1.3. The finding of such a small difference is partly explainable by the fact that only few components dominate the mixture scenario in terms of so-called toxic units (TUs). This connection is established by developing an equation that allows to calculate the maximum possible ratio between corresponding predictions of effect concentrations by IA and CA for any given ratio of the TUs of mixture components, irrespective of their individual concentration-response functions and independent from their mechanisms of action. To evaluate whether small quantitative differences between EC(50) values predicted by CA and IA are an exception or rather the rule for agricultural exposure scenarios, this calculation was applied on an additional set of 18 pesticide exposure scenarios that were taken from the literature. For these scenarios, EC(50) values predicted by IA can never exceed those predicted by CA by more than a factor of 2.5. The findings of this study support the view that CA provides a precautious but not overprotective approach to the predictive hazard assessment of pesticide mixtures under realistic exposure scenarios, irrespective of the similarity or dissimilarity of their mechanisms of action. PMID:16310872

Junghans, Marion; Backhaus, Thomas; Faust, Michael; Scholze, Martin; Grimme, L H

2006-02-10

104

Development and validation of methodology for the determination of residues of organophosphorus pesticides in tomatoes  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese Os pesticidas organofosforados são freqüentemente aplicados no cultivo de tomate no Brasil. No presente trabalho uma metodologia analítica foi desenvolvida e validada para a quantificação de resíduos dos pesticidas organofosforados acefato, chlorpyrifós, malation, metamidofós and paration metílico e [...] m tomate, empregando Cromatografia Gasosa com Detector de Nitrogênio e Fósforo (GC-NPD). A possibilidade de ocorrência de efeito matriz foi estudada. As curvas analíticas, preparadas nos extratos da matriz, foram lineares de 0,006 até 0,80 mg L-1. Os estudos de precisão forneceram resultados com RSD Abstract in english The organophosphorus pesticides are frequently applied in tomato cultivation in Brazil. In the present work an analytical methodology for quantification of the organophosphorus pesticides: acephate, chlorpyrifos, malathion, methamidophos and parathion-methyl residues in tomatoes was developed and va [...] lidated using Gas Chromatography with a Nitrogen-Phosphorus Detector (GC-NPD). The possibility of a matrix effect was studied. Analytical curves prepared in an extract of the matrix were linear from 0.006 to 0.80 mg L-1. The precision studies supplied results with RSD

Anagilda B., Gobo; Márcia H. S., Kurz; Ionara R., Pizzutti; Martha B., Adaime; Renato, Zanella.

2004-12-01

105

Ethyl N-[(benzyloxythiocarbonyl]carbamate  

Directory of Open Access Journals (Sweden)

Full Text Available In the title compound, C11H13NO3S, the dihedral angle between the benzyl and carbamate groups is 12.67?(10°. The S atom and the carbonyl O atom are positioned anti to each other. In the crystal, pairs of N—H...S hydrogen bonds link molecules into inversion dimers.

Sung Kwon Kang

2012-02-01

106

Determination of carbamates in beverages by liquid-liquid extraction with low temperature partitioning and liquid chromatography  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese Carbamatos são os pesticidas mais frequentemente encontrados em alimentos e bebidas de coloração escura em casos de intoxicação acidental ou intencional. Neste trabalho, extração líquido-líquido com partição em baixa temperatura (LLE-LTP) foi otimizada e validada para determinação dos carbamatos ald [...] icarb, carbofuran e carbaril em bebidas de sucos de uva e leite achocolatado. Este método envolve a extração com acetonitrila, partição líquido-líquido em baixa temperatura e análise por cromatografia líquida de alta eficiência com detecção ultravioleta (HPLC-UV). O método é rápido, eficiente e de baixo custo, emprega pequenos volumes de solvente por amostra e não necessita de limpeza dos extratos. O método de extração foi seletivo e apresentou porcentagens de extração acima de 90%. As premissas relacionadas com os testes estatísticos de linearidade foram verificadas e confirmadas. O método de extração e análise foi validado com resultados satisfatórios e pode ser aplicado em análises de rotina e forenses. Abstract in english Carbamates are the pesticides most commonly found in dark colored foods and beverages in cases of accidental or intentional poisoning. In this work, the liquid-liquid extraction with low temperature partitioning (LLE-LTP) was optimized and validated for determination of the carbamates aldicarb, carb [...] ofuran and carbaryl in grape juice and chocolate milk beverages. This method involved extraction with acetonitrile, liquid-liquid partition at low temperature and the analysis by high performance liquid chromatography with ultraviolet detection (HPLC-UV). The method is rapid, efficient and of low-cost, employing small volumes of solvent per sample and requiring no cleanup of the extracts. The extraction methodology was selective and presented recovery percentages above 90%. The premises related to the statistical linearity tests were checked and confirmed. The method of extraction and analysis was validated with satisfactory results, and may be applied in forensic and routine analysis.

Simone M., Goulart; Renata D., Alves; Washington X. de, Paula; José Humberto de, Queiroz; Antônio A., Neves; Maria Eliana L. R. de, Queiroz.

1154-11-01

107

Measurement of pesticides and other toxicants in amniotic fluid as a potential biomarker of prenatal exposure: a validation study.  

OpenAIRE

Prenatal pesticide exposures may adversely affect children's health. However, exposure and health research is hampered by the lack of reliable fetal exposure data. No studies have been published that report measurements of commonly used nonpersistent pesticides in human amniotic fluid, although recent studies of pesticides in urine from pregnant women and in meconium indicate that fetuses are exposed to these chemicals. Amniotic fluid collected during amniocentesis is the only medium availabl...

Bradman, Asa; Barr, Dana B.; Claus Henn, Birgit G.; Drumheller, Timothy; Curry, Cynthia; Eskenazi, Brenda

2003-01-01

108

40 CFR 721.2025 - Substituted phenylimino carbamate derivative.  

Science.gov (United States)

...2010-07-01 false Substituted phenylimino carbamate derivative. 721.2025 Section 721...721.2025 Substituted phenylimino carbamate derivative. (a) Chemical substance...generically as a substituted phenylimino carbamate derivative (PMN P-91-487)...

2010-07-01

109

21 CFR 520.434 - Chlorphenesin carbamate tablets.  

Science.gov (United States)

...2010-04-01 false Chlorphenesin carbamate tablets. 520.434 Section 520...ANIMAL DRUGS § 520.434 Chlorphenesin carbamate tablets. (a) Specifications. ...contains 400 milligrams of chlorphenesin carbamate. (b) Sponsor. See No....

2010-04-01

110

40 CFR 721.2025 - Substituted phenylimino carbamate derivative.  

Science.gov (United States)

... Substituted phenylimino carbamate derivative. 721.2025 Section 721.2025... Substituted phenylimino carbamate derivative. (a) Chemical substance and significant...as a substituted phenylimino carbamate derivative (PMN P-91-487) is subject...

2010-07-01

111

Types of pesticides and determination of their residues  

International Nuclear Information System (INIS)

The pesticide is any material or component used to protect from pests. Its toxic effect is related to the chemical structure, which can be divided into 3 types : 1- Metal pesticides : Sulphur, cupper, zinc, mercury; 2- Vegetal pesticides : advanced and less toxic to the general health; 3- Synthetic organo pesticides : organo chlorine, organophosphorous, carbamate and pyrethroids. Pesticides in the soil undergo biological dissociation according to their concentration and chemical structure. High concentration of the pesticides in the soil may lead to fertility decrease due to destruction of micro-organisms by the pesticides. Many methods are used to analyze the residues of pesticides in plant or soil : 1- Chromatographic methods : Gas chromatography, gas liquid chromatography and high performance liquid chromatography; 2- Spectroscopy methods : spectrophotometer and mass spectrometer; 3- Isotopic methods : based on tracers technique which is the most sensitive and accurate method and can estimate minor amounts of the pesticides. (author)

112

Validation of a qualitative screening method for pesticides in fruits and vegetables by gas chromatography quadrupole-time of flight mass spectrometry with atmospheric pressure chemical ionization.  

Science.gov (United States)

A wide-scope screening method was developed for the detection of pesticides in fruit and vegetables. The method was based on gas chromatography coupled to a hybrid quadrupole time-of-flight mass spectrometer with an atmospheric pressure chemical ionization source (GC-(APCI)QTOF MS). A non-target acquisition was performed through two alternating scan events: one at low collision energy and another at a higher collision energy ramp (MS(E)). In this way, both protonated molecule and/or molecular ion together with fragment ions were obtained in a single run. Validation was performed according to SANCO/12571/2013 by analysing 20 samples (10 different commodities in duplicate), fortified with a test set of 132 pesticides at 0.01, 0.05 and 0.20mg kg(-1). For screening, the detection was based on one diagnostic ion (in most cases the protonated molecule). Overall, at the 0.01mg kg(-1) level, 89% of the 2620 fortifications made were detected. The screening detection limit for individual pesticides was 0.01mg kg(-1) for 77% of the pesticides investigated. The possibilities for identification according to the SANCO criteria, requiring two ions with a mass accuracy ?±5ppm and an ion-ratio deviation ?±30%, were investigated. At the 0.01mg kg(-1) level, identification was possible for 70% of the pesticides detected during screening. This increased to 87% and 93% at the 0.05 and 0.20mg kg(-1) level, respectively. Insufficient sensitivity for the second ion was the main reason for the inability to identify detected pesticides, followed by deviations in mass accuracy and ion ratios. PMID:25064246

Portolés, T; Mol, J G J; Sancho, J V; López, Francisco J; Hernández, F

2014-08-01

113

Complete heart block following intentional carbamate ingestion  

OpenAIRE

Organophosphates and carbamate compounds are acetylcholinesterase inhibitors used as agricultural insecticides and represent a common cause of cholinergic toxicity. Cardiac manifestations of organophosphate and carbamate toxicity are described primarily from reports of organophosphate exposure and include sinus bradycardia, prolonged PR interval, sinus tachycardia, prolonged corrected QT interval and ventricular arrhythmias. Complete atrioventricular block has rarely been reported with insect...

Siegal, Deborah; Kotowycz, Mark A.; Methot, Michelle; Baranchuk, Adrian

2009-01-01

114

[Pesticide residues in drinking water of an agricultural community in the state of Mérida, Venezuela].  

Science.gov (United States)

The aim of this study was to determine the presence of pesticides in drinking water from six aqueducts in a region of intense agricultural activity in the state of Merida, Venezuela. The study was conducted for four continuous weeks, between May and June 2008. Pesticide residues were analyzed by solid phase extraction (SPE) and liquid chromatography (HPLC) with diode array detector (DAD). The method SPE-HPLC-DAD met the criteria of analytical validation, with good linearity (R2: 0.9840 to 0.9999), precision (coefficient of inter-day variability from 1.47 to 6.25%), accuracy (relative standard deviation 0.9 to 9.20%) and sensitivity (LOD mancozeb with 0.400 microg/L). Seven of the thirteen selected pesticides have a recovery rate between 100% and 70%, the rest between 61% and 37%. Ten pesticides of the following chemical groups, were detected in 72 samples analyzed: organophosphates, carbamates, triazines and urea derivatives. The pesticides with the highest frequency of detection were: carbofuran and atrazine (39%), malathion (25%), dimethoate and metribuzin (19%). The pesticides found at high levels were diazinon (26.31 microg/L), methamidophos (10.99 microg/L), malathion (2.03 microg/L) and mancozeb (1.27 microg/L). Pesticide levels did not exceed the maximum allowed by Venezuelan law, however, according to international standards (EU and EPA-USA) values were above the maximum permissible levels. This study demonstrates the urgent need for systematic monitoring of the quality of water for human consumption in regions of high agricultural productivity. PMID:22523840

Flores-García, Mery Elisa; Molina-Morales, Yuri; Balza-Quintero, Alirio; Benítez-Díaz, Pedro Rafael; Miranda-Contreras, Leticia

2011-12-01

115

Phthalates, Pesticides, and Bisphenol-A Exposure and the Development of Nonoccupational Asthma and Allergies: How Valid Are the Links?  

OpenAIRE

Phthalates, pesticides, and bisphenol-A (BPA) are three groups of chemicals, implicated in endocrine disruption and commonly found in the local environment, that have been implicated in the pathogenesis of asthma and allergies [1-3]. Multiple observational studies have demonstrated an association between exposure to phthalates and the development of asthma and allergies in humans. Associations with exposure to pesticides and BPA and the development of respiratory disease are less clear. Howev...

Kwak, Eun Soo; Just, Allan; Whyatt, Robin; Miller, Rachel L.

2009-01-01

116

Development and validation of method for the determination of organochlorine pesticides and trihalomethanes in the water by HRGC-ECD - 10.4025/actascitechnol.v32i4.7689 Development and validation of method for the determination of organochlorine pesticides and trihalomethanes in the water by HRGC-ECD - 10.4025/actascitechnol.v32i4.7689  

Directory of Open Access Journals (Sweden)

Full Text Available The development and validation of a simultaneous liquid-liquid extraction method for organochlorine pesticides and trihalomethanes in surface and drinking water by HRGC-ECD is described. The method presents acceptable recovery, with detection ranging from 2.7 to 49.0 ng L-1 for organochlorine pesticides and from 18.0 to 860.0 ng L-1 for trihalomethanes. The extraction method also presents excellent linearity for all the analytes, with excellent repeatability. Extraction is simple, fast, and low cost, uses small amounts of solvent and aqueous sample, and is suitable for routine analyses.The development and validation of a simultaneous liquid-liquid extraction method for organochlorine pesticides and trihalomethanes in surface and drinking water by HRGC-ECD is described. The method presents acceptable recovery, with detection ranging from 2.7 to 49.0 ng L-1 for organochlorine pesticides and from 18.0 to 860.0 ng L-1 for trihalomethanes. The extraction method also presents excellent linearity for all the analytes, with excellent repeatability. Extraction is simple, fast, and low cost, uses small amounts of solvent and aqueous sample, and is suitable for routine analyses.

Maria Isabel Ribeiro Alves

2010-12-01

117

76 FR 34200 - Land Disposal Restrictions: Revision of the Treatment Standards for Carbamate Wastes  

Science.gov (United States)

...Restrictions: Revision of the Treatment Standards for Carbamate Wastes AGENCY: Environmental Protection Agency...standards for hazardous wastes from the production of carbamates and carbamate commercial chemical products,...

2011-06-13

118

Validation of a multi-residue method for the determination of residuals pesticides in cabbage (Brassica Oleracea var. Capitata) for gases chromatography  

International Nuclear Information System (INIS)

This study describes the validation of a multi-residue method for the determination of most used organo chlorine, organophosphorus and organonitrogen pesticides in cabbage in the Cundinamarca Department (Colombia). The extraction process includes blending of small sample quantity with ethyl acetate in presence of Na2SO4 and NaHCO3, filtration and concentration. The clean up steps include GPC and mini-column chromatography using silica gel. Final determination was carried out by gas chromatography with: pulsed splitless injection, HP-5 capillary column, and a parallel detection system with micro electron capture detection (? - ECD) and Nitrogen-Phosphorus Detection (NPD). The methodology is specific, selective, accurate and robust. Recovery values of majority of pesticides were in the range 70-120% at spiking levels ranging 0.05-10.73 mg/kg. Limits of detection were less than 0.10 mg/kg for most of the studied compounds. The distribution of the analyses in the laboratory sample was evaluated and it was found its homogeneity. The evaluation of pesticide residues was made in a specific area of municipality of Madrid-Cundinamarca, (Colombia). No residues of the studied analyses were founded

119

A SURVEY OF EPA/OPP AND OPEN LITERATURE ON SELECTED PESTICIDE CHEMICALS III. MUTAGENICITY AND CARCINOGENICITY OF BENOMYL AND CARBENDAZIM  

Science.gov (United States)

Abstract The known aneuploidogens, benomyl and its metabolite, carbendazim (methyl 2- benzimidazole carbamate or MBC), were selected for the third in a series of ongoing projects with selected pesticides. Mutagenicity and carcinogenicity data submitted to the U.S. Environmen...

120

A PHYSIOLOGICALLY BASED PHARMACOKINETIC/PHARMACODYNAMIC (PBPK/PD) MODEL FOR ESTIMATION OF CUMULATIVE RISK FROM EXPOSURE TO THREE N-METHYL CARBAMATES: CARBARYL, ALDICARB, AND CARBOFURAN  

Science.gov (United States)

A physiologically-based pharmacokinetic (PBPK) model for a mixture of N-methyl carbamate pesticides was developed based on single chemical models. The model was used to compare urinary metabolite concentrations to levels from National Health and Nutrition Examination Survey (NHA...

121

Carbamic acid and carbamate formation in NH{3}:CO{2} ices - UV irradiation versus thermal processes  

Science.gov (United States)

Context: We study carbamic acid [ NH{2}COOH] and ammonium carbamate [ NH{2}COO-] [ NH{4}+] formation in interstellar ice analogs. Aims: We demonstrate how carbamic acid [ NH{2}COOH] and ammonium carbamate [ NH{2}COO-] [ NH{4}+] can be formed from both thermal reactions and energetic photons in an NH{3}:CO{2} ice mixture. Methods: Infrared and mass spectroscopy are used to monitor NH{3}:CO{2} ice mixture evolution during both warming and VUV photon irradiation. Results: Carbamic acid and ammonium carbamate can be produced thermally in a 1:1 ratio from NH{3} and CO{2} above 80 K. They can be also formed in a 28:1 ratio by less efficient processes such as energetic photons. Our study and its results provide fresh insight into carbamic acid formation in interstellar ices. Conclusions: We demonstrate that care is required to separate irradiation-induced reactivity from purely thermal reactivity in ices in which ammonia and carbon dioxide are both present. From an interstellar chemistry point of view, carbamic acid and ammonium carbamate are readily produced from the ice mantle of a typical interstellar grain and should therefore be a detectable species in molecular clouds.

Bossa, J. B.; Theulé, P.; Duvernay, F.; Borget, F.; Chiavassa, T.

2008-12-01

122

[Assessment on acute toxicity of combined pesticides].  

Science.gov (United States)

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. PMID:12725074

Sun, J; Chen, B; Yao, P

2000-03-30

123

DOSE-RESPONSE MODELING FOR ASSESSING CUMULATIVE PESTICIDE RISK  

Science.gov (United States)

This project is still in its early phases. Future work in this area will involve theoretical analyses of the limits of dose-additivity assumptions, and physiologically-based pharmacokinetic and pharmacodynamic (PBPK/PD) models for n-methyl carbamate and pyrethroid pesticides (in ...

124

A calorimetric study of carbamate formation  

International Nuclear Information System (INIS)

Research highlights: ? MEA-, DEA-, and ammonia-carbamate formation enthalpies have been measured. ? This is the first direct determination of carbamate formation enthalpies. ? Carbamate formation enthalpies follow trends in amine protonation enthalpies. - Abstract: Post combustion capture of CO2 (PCC) is currently one of the leading technologies for the reduction of green house gas emissions from power plants. The most common PCC process is based on the absorption of CO2 into aqueous amine solutions. CO2 absorption involves several parallel reactions including hydration of CO2; deprotonation of carbonic acid; protonation of the amine; and formation of carbamate. The extent to which each reaction proceeds is dependent on the conditions of absorption (or desorption), as well as the associated equilibrium constants. All reactions other than carbamate formation have been extensively investigated previously. The investigation of carbamate formation is more complex, as it cannot be studied in the absence of other, simultaneous reactions. In particular, the enthalpy of carbamate formation has been determined previously only from the temperature dependence of equilibrium constants, but this methodology is not robust. In this contribution, we use calorimetry and advanced model-based data analysis methods for the unravelling of the thermo-chemistry relevant to PCC and specifically directly determine the reaction enthalpy for carermine the reaction enthalpy for carbamate formation. The reaction enthalpies of carbamate formation and amine protonation were measured in dilute aqueous solution at 298 K using isothermal titration calorimetry (ITC) for monoethanolamine (MEA), diethanolamine (DEA), and ammonia (NH3). The enthalpy of protonation was also measured for carbonate and bicarbonate. The re-determined protonation constants of the carbonate species and the three amines are in excellent agreement with previously reported results. No measured enthalpies of carbamate formation have been reported previously. For the carbamate formation reaction HCO3-+R'RNH?R'RNCO2-, the following reaction enthalpies were determined: MEA, -29.7 ± 0.1 kJ/mol; DEA, -23.7 ± 0.9 kJ/mol, and NH3, -27.6 ± 0.9 kJ/mol. The results are in good agreement with, but much more precise and robust than estimated values reported in the literature.

125

Phyt'Eaux Cités: application and validation of a programme to reduce surface water contamination with urban pesticides.  

Science.gov (United States)

This paper presents first results of Phyt'Eaux Cités, a program put in place by the local water supply agency, the SEDIF (Syndicat des Eaux d'Ile-de-France), in collaboration with 73 local authorities, private societies and institutional offices (365 km(2)). The challenges included: measurement of the previous surface water contamination, control of urban pesticide applications, prevention of pesticide hazard on users and finally a overall reduction of surface water contamination. An inquiry on urban total pesticide amount was coupled with a surface water bi-weekly monitoring to establish the impact of more than 200 molecules upon the Orge River. For 2007, at least 4400 kg and 92 type of pesticides (essentially herbicides) were quantified for all urban users in the Phyt'Eaux Cités perimeter. At the outlet of the Orge River (bi-weekly sampling in 2007), 11 molecules were always detected above 0.1 ?g L(-1). They displayed the mainly urban origin of pesticide surface water contamination. Amitrole, AMPA (Aminomethyl Phosphonic Acid), demethyldiuron, diuron, glyphosate and atrazine were quantified with a 100% of frequency in 2007 and 2008 at the Orge River outlet. During the year, peaks of contamination were also registered for MCCP, 2,4 MCPA, 2,4 D, triclopyr, dichlorprop, diflufènican, active substances used in large amount in the urban area. However, some other urban molecules, such as isoxaben or flazasulfuron, were detected with low frequency. During late spring and summer, contamination patterns and load were dominated by glyphosate, amitrole and diuron, essentially applied by cities and urban users. Both isoproturon and chlortoluron were quantified during autumn and winter months according to upstream agricultural practices. In conclusion, 3 years after the beginning of this programme, the cities reduced the use of 68% of the total pesticide amount. An improvement on surface water quality was found from 2008 and during 2009 for all pesticides. In particular, glyphosate showed a decrease of the load above 60% in 2008, partly related to the Phyt'Eaux Cités action. PMID:22078267

Botta, Fabrizio; Fauchon, Nils; Blanchoud, Hélène; Chevreuil, Marc; Guery, Bénédicte

2012-01-01

126

Fluorimetric Determination of Carbamate Pesticides in Host-Guest Complexes  

Directory of Open Access Journals (Sweden)

Full Text Available From the effect of β-cyclodextrin and hydroxypropyl-β-cyclodextrin on the UVvisible and fluorescence spectra of carbaryl and carbofuran, the values of association constants were determined. The ratio of the fluorescence quantum yields for the bound and free substrates indicated an enhanced fluorimetric method of detection.

Alicia Viviana Veglia

2000-03-01

127

Determination of seventeen polar/thermolabile pesticides in apples and apricots by liquid chromatography/mass spectrometry.  

Science.gov (United States)

A simple liquid chromatography/mass spectrometry (LC/MS) approach for the determination of widely used representatives of polar/thermolabile pesticides in fruits was developed and validated. The group of pesticides comprised benzimidazoles and azoles (carbendazim, thiabendazole, imazalil, propiconazole, prochloraz, epoxiconazole, flusilazole, tebuconazole, bitertanol); N-methylcarbamates (carbaryl, carbofuran, methiocarb); and phenylureas and benzoylphenylureas (linuron, diflubenzuron, triflumuron, teflubenzuron, flufenoxuron). Matrixes (apple, apricot) were extracted with acetonitrile and crude extracts were cleaned up by solid-phase extraction (SPE) using either mixed cation exchange or hydrophilic lipophilic balance cartridges. LC separation of pesticides was performed on a reversed-phase column, Discovery C18. Electrospray ionization and ion trap MS/MS detection were applied. For most pesticides, overall recoveries ranged from 75 to 122%, and repeatability (as relative standard deviation) from 5 repetitive determinations of recovery ranged from 3 to 21%. Carbofuran was the only compound for which recovery was not satisfactory due to its loss in the SPE cleanup step. Limits of detection were 0.1-3 microg/kg for benzimidazole and azole fungicides and carbamate insecticides. For urea insecticides, detection limits were slightly higher (3-10 microg/kg). PMID:12852583

Zrostlíková, Jitka; Hajslová, Jana; Kovalczuk, Tomás; St?pán, Radim; Poustka, Jan

2003-01-01

128

Age dependence of organophosphate and carbamate neurotoxicity in the postnatal rat: extrapolation to the human  

International Nuclear Information System (INIS)

One important aspect of risk assessment for the organophosphate and carbamate pesticides is to determine whether their neurotoxicity occurs at lower dose levels in human infants compared to adults. Because these compounds probably exert their neurotoxic effects through the inhibition of acetylcholinesterase (AChE), the above question can be narrowed to whether the cholinesterase inhibition and neurotoxicity they produce is age-dependent, both in terms of the effects produced and potency. The rat is the animal model system most commonly used to address these issues. This paper first discusses the adequacy of the postnatal rat to serve as a model for neurodevelopment in the postnatal human, concluding that the two species share numerous pathways of postnatal neurodevelopment, and that the rat in the third postnatal week is the neurodevelopmental equivalent of the newborn human. Then, studies are discussed in which young and adult rats were dosed by identical routes with organophosphates or carbamates. Four pesticides were tested in rat pups in their third postnatal week: aldicarb, chlorpyrifos, malathion, and methamidophos. The first three, but not methamidophos, caused neurotoxicity at dose levels that ranged from 1.8- to 5.1-fold lower (mean 2.6-fold lower) in the 2- to 3-week-old rat compared to the adult. This estimate in the rat, based on a limited data set of three organophosphates and a single carbamate, probably represents the minimum difference in the neurotoxits the minimum difference in the neurotoxicity of an untested cholinesterase-inhibiting pesticide that should be expected between the human neonate and adult. For the organophosphates, the greater sensitivity of postnatal rats, and, by analogy, that expected for human neonates, is correlated with generally lower levels of the enzymes involved in organophosphate deactivation

129

Ab Initio Investigations of the Hydrolysis of the Carbamate Bond  

OpenAIRE

The energies for model gas-phase decomposition and hydrolysis reactions ofcarbamic acid and methyl carbamate have been calculated at various levels of theory. The calculations indicate that esterification accelerates cleavage of the carbamate bond.

Remko, M.; Scheiner, Steve

1990-01-01

130

21 CFR 520.434 - Chlorphenesin carbamate tablets.  

Science.gov (United States)

... Chlorphenesin carbamate tablets. 520.434 Section 520...AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.434 Chlorphenesin carbamate tablets. (a) Specifications. Each tablet contains 400...

2010-04-01

131

Development and validation of a multi-residue method for pesticide determination in honey using on-column liquid-liquid extraction and liquid chromatography-tandem mass spectrometry  

OpenAIRE

We report on the development and validation under ISO 17025 criteria of a multi-residue confirmatory method to identify and quantify 17 widely chemically different pesticides (insecticides: Carbofuran, Methiocarb, Pirimicarb, Dimethoate, Fipronil, Imidacloprid; herbicides: Amidosulfuron, Rimsulfuron, Atrazine, Simazine, Chloroturon, Linuron, Isoxaflutole, Metosulam; fungicides: Diethofencarb) and 2 metabolites (Methiocarb sulfoxide and 2-Hydroxytertbutylazine) in honey. This method is based o...

Pirard, Catherine; Widart, Joe?lle; Nguyen, Bach Kim; Deleuze, Christelle; Heudt, Laetitia; Haubruge, Eric; Pauw, Edwin; Focant, Jean-franc?ois

2007-01-01

132

Total Pesticide Exposure Calculation among Vegetable Farmers in Benguet, Philippines  

OpenAIRE

This was a cross-sectional study that investigated pesticide exposure and its risk factors targeting vegetable farmers selected through cluster sampling. The sampling size calculated with P = .05 was 211 vegetable farmers and 37 farms. The mean usage of pesticide was 21.35 liters. Risk factors included damaged backpack sprayer (34.7%), spills on hands (31.8%), and spraying against the wind (58%). The top 3 pesticides used were pyrethroid (46.4%), organophosphates (24.2%), and carbamates (21.3...

Lu, Jinky Leilanie

2009-01-01

133

Determining Historical Pesticide Deposition on Cape Cod through Sediment Core Analysis:A Validation of GIS as An Exposure Assessment Tool  

Science.gov (United States)

Geographic Information Systems (GIS) has emerged as a powerful tool to assess current and historical exposure to environmental pollutants. GIS aids in the visualization and understanding of associations between exposure to contaminants and disease. This study is an example of the bridge between environmental science and public health and of how new technology such as GIS can be incorporated into these fields to strengthen both the research and the communication of scientific results. It attempts to validate a GIS-based aerial drift model which predicts the residential exposure to and boundaries of historical organochlorine pesticide (OCP) drift from applications on cranberry bogs, tree pest sprayings and others by analytically quantifying the historical pesticide deposition in a transect of lakes radiating from a distinct spray source. This model was previously used to assess historical residential exposure to OCPs in an environmental epidemiological case-control study of breast cancer incidence on Cape Cod, MA, where the incidence rate of the disease is significantly higher than in the rest of the state. The model's validation in this current study is essential to establishing its predictive ability and thus, its further use. Ground truthing of the model was done through the collection and analysis of sediment cores along a transect of five hydrologically independent kettle ponds radiating from a distinct OCP tree-pest spray area. Measurements of OCP concentrations, total carbon and total organic carbon were determined, and dating of the sediments was completed using 210Pb and verified using 137Cs. Each 50-cm core was sliced into 25 2- cm sections for the analyses, creating a fine-scale depositional history in each pond. Information gathered from each core allows for the determination of the extent and degree of dissipation of individual spray events of a known source area and determine how well the model fits the actual data.

Feingold, B. J.; Benoit, G.; Rudel, R.

2006-12-01

134

QuEChERS GC-MS validation and monitoring of pesticide residues in different foods in the tomato classification group.  

Science.gov (United States)

The objective of this study was to validate (SANCO/12495/2011 and NTC-ISO/IEC 17025) multi-residue multi-class methods using QuEChERS sample preparation and GC-MS for the analysis of regulated pesticides in tomatoes (Solanum lycopersicum), tamarillos (Solanum betaceum) and goldenberries (Physalis peruviana). These Latin American products are representative and widely produced in Antioquia (Colombia). Sample preparation followed the UNE-EN 15662 method (150 mg MgSO4, 25mg primary secondary amines and 25mg of octadecylsiloxane for cleanup; graphitized carbon black was added for tomatoes). Extracts were injected using a programmed temperature-vaporizing injector. The residues were validated over a range from 0.02 mg/kg to 0.20 mg/kg, with 24 analytes validated in tomatoes, 33 in tamarillos and 28 in goldenberries. An initial risk assessment was enabled by monitoring 24 samples in the municipalities of El Peñol, Marinilla and San Vicente Ferrer. Risks were found for tomatoes, but no significant risks were found for tamarillos or goldenberries. PMID:24731326

Ramírez Restrepo, Andrés; Gallo Ortiz, Andrés Fernando; Hoyos Ossa, Duvan Esteban; Peñuela Mesa, Gustavo Antonio

2014-09-01

135

Pesticides and the Third World.  

Science.gov (United States)

Many developing countries are importing industrial processes that make use of toxic chemicals. By the same token, pesticides, which are toxic by design, are also used increasingly in agriculture and in public health programs to control pests and vector-borne diseases. Recent estimates suggest that pesticides account for more than 20,000 fatalities yearly, and that most of these will have occurred in developing countries. This may actually be a gross underreporting. Although organophosphate and carbamate insecticides are still responsible for many of those poisoning cases, herbicides such as paraquat are also increasingly being implicated in fatal poisoning cases. Newer pesticides such as the synthetic derivatives of pyrethrin, which were believed to be relatively safe to humans, now appear to be implicated in some serious cases of intoxication. Community-based pest control using locally available botanical pesticides could have severe consequences unless the toxicity of these compounds is carefully assessed relative to nontarget organisms. A high proportion of pesticide intoxications appear to be due to lack of knowledge, unsafe attitudes, and dangerous practices. The technology available to small farmers for pesticide application is often inappropriate: faulty sprayers, lack of protective equipment adapted to tropical conditions, nonexistent first-aid provisions. Agricultural extension is often not oriented to the transfer of information relative to the dangers inherent in the use of pesticides. The lack of information at all levels may be one of the most important causative factors of chemical intoxication in developing countries. Research should at this time concentrate on behaviors leading to chemical intoxication. This should be done concurrently with proper prospective and retrospective surveys of poisonings in developing country communities. More information should be sought relative to the decision processes of import, legislation, and licensing. Research and development efforts in appropriate technology and safety devices are also critically needed. PMID:1987360

Forget, G

1991-01-01

136

Acute pesticide poisoning in England and Wales.  

Science.gov (United States)

Between 1979 and 1983 less than 1% of admissions from acute poisoning in the UK were due to pesticides and fewer than 4% of admissions in those under 5 years were from this cause. Organochlorine, organophosphorus and carbamate insecticides account for only 10% of the total in both children and adults. Suspected pesticide poisoning was the cause of fewer than 0.3% of home accidents in those under 10 years of age and less than 4% of suspected poisonings documented by the Home Accident Surveillance System. Rodenticides were thought to be involved in 62% of these cases. Of children who presented to hospital 42% were admitted and 93% of these were discharged home within 2 days. In the UK, the morbidity from acute pesticide poisoning in children is low and the mortality is nil and there is therefore no evidence to support the view that paediatric pesticide intoxication is a significant clinical problem. Though no fatalities were recorded in children, pesticides were responsible for 1.3% of all deaths due to poisoning in the UK between 1979 and 1983. In adults admitted to hospital, the mortality from pesticide poisoning is approximately 12% and three quarters of these deaths are due to the deliberate ingestion of paraquat. The general term pesticide refers to a group of products that are used as insecticides, acaricides, fungicides, herbicides, rodenticides, and plant growth agents. Chemically, the group includes bipyridilium compounds, carbamates, chloralose, chlorates, coumarins, dinitro compounds, dithiocarbamates, fluoroacetates, organochlorine organophosphorus and organotin compounds, pentachlorophenol, phenoxyacetates, phosphine (as magnesium and aluminium phosphides), pyrethrins, pyrethroids and triazines.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:10281618

Vale, T J; Meredith, T J; Buckley, B M

1987-02-01

137

A new multi-residue method for analysis of pesticide residues in fruit and vegetables using liquid chromatography with tandem mass spectrometric detection.  

Science.gov (United States)

A new multi-residue method for determination of pesticide residues in a wide variety of fruit and vegetables, using the National Food Administration (NFA) ethyl acetate extraction and determination by means of LC-MS/MS, is presented. The method includes pesticides normally detected by LC-UV or LC-fluorescence such as benzimidazoles, carbamates, N-methylcarbamates and organophosphorus compounds with an oxidisable sulphide group as well. After extraction with ethyl acetate, the extract is concentrated and an aliquot of the extract is evaporated to dryness and redissolved in methanol before injection on LC-MS/MS. The method has been validated for 57 different pesticides and metabolites. Representative species from different commodity groups were chosen as matrices in order to study the influence from different matrices on recoveries. The fortification levels studied were 0.01-0.5 mg kg(-1). Matrix effects were tested for all matrices by means of standard addition to blank extracts. The matrix effect, expressed as signal in solvent compared to signal in matrix, was in general found to be small. The obtained recoveries are, with a few exceptions, in the range 70-100%. The proposed method is quick and straightforward and no additional clean-up steps are needed. The method can be used for the analysis of all 57 pesticides in one single determination step at 0.01 mg kg(-1). PMID:14760853

Jansson, Christer; Pihlström, Tuija; Osterdahl, Bengt-Göran; Markides, Karin E

2004-01-01

138

Validação de método multirresíduo para determinação de pesticidas em alimentos empregando QuEChERS E UPLC-MS/MS / Multiresidue method validation for determination of pesticides in food using QuEChERS and UPLC-MS/MS  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese [...] Abstract in english This paper presents a practical and rapid method which was validated for simultaneous quantification and confirmation of 29 pesticides in fruits and vegetables using ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The samples were extracted following the method known a [...] s QuEChERS. Using the developed chromatographic conditions, the pesticides can be separated in less than 9 min. Two multiple reaction monitoring (MRM) assays were used for each pesticide. Four representative matrices (lettuce, tomato, apple and grapes) were selected to investigate the effect in recoveries and precision. Typical recoveries ranged from 70-120%, with relative standard deviation (RSDs) lower than 20%.

Sonia C. N., Queiroz; Vera L., Ferracini; Maria A., Rosa.

139

Ethyl N-[(benzyloxy)thiocarbonyl]carbamate  

OpenAIRE

In the title compound, C11H13NO3S, the dihedral angle between the benzyl and carbamate groups is 12.67?(10)°. The S atom and the carbonyl O atom are positioned anti to each other. In the crystal, pairs of N—H...S hydrogen bonds link molecules into inversion dimers.

Sung Kwon Kang; Nam Sook Cho; Min Kyeong Jeon

2012-01-01

140

Phenyl N-(2-methylphenyl)carbamate  

OpenAIRE

In the title compound, C14H13NO2, the aromatic rings attached to the O and N atoms make dihedral angles of 62.65?(9) and 38.28?(11)°, respectively, with the central carbamate group. The benzene rings are oriented at a dihedral angle of 39.22?(10)°. In the crystal, a very weak C—H...? interaction occurs.

Durre Shahwar; Nawaz Tahir, M.; Naeem Ahmad; Asma Yasmeen; Saif Ullah

2009-01-01

141

Pesticides residues in water treatment plant sludge: validation of analytical methodology using liquid chromatography coupled to Tandem mass spectrometry (LC-MS/MS)  

International Nuclear Information System (INIS)

The evolving scenario of Brazilian agriculture brings benefits to the population and demands technological advances to this field. Constantly, new pesticides are introduced encouraging scientific studies with the aim of determine and evaluate impacts on the population and on environment. In this work, the evaluated sample was the sludge resulted from water treatment plant located in the Vale do Ribeira, Sao Paulo, Brazil. The technique used was the reversed phase liquid chromatography coupled to electrospray ionization tandem mass spectrometry. Compounds were previously liquid extracted from the matrix. The development of the methodology demanded data processing in order to be transformed into reliable information. The processes involved concepts of validation of chemical analysis. The evaluated parameters were selectivity, linearity, range, sensitivity, accuracy, precision, limit of detection, limit of quantification and robustness. The obtained qualitative and quantitative results were statistically treated and presented. The developed and validated methodology is simple. As results, even exploring the sensitivity of the analytical technique, the work compounds were not detected in the sludge of the WTP. One can explain that these compounds can be present in a very low concentration, can be degraded under the conditions of the water treatment process or are not completely retained by the WTP. (author)

142

Development and validation of a method using SPE and LC-ESI-MS-MS for the determination of multiple classes of pesticides and metabolites in water samples  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese Um método analítico baseado na extração em fase sólida e cromatografia líquida acoplada à espectrometria de massas tandem (LC-ESI-MS-MS) foi desenvolvido e validado para a determinação e confirmação de dezoito agrotóxicos (herbicidas, inseticidas e fungicidas) e dois metabólitos em amostras de água. [...] Os limites de detecção variaram de 0,4 a 40,0 ng L-1 e os limites de quantificação de 4,0 a 100,0 ng L-1. Foi obtida boa linearidade, com r² > 0,99 para todos os compostos. As recuperações, para 95% dos compostos, variaram de 70 a 120%, com RSDs menores que 21% para todos. Através do monitoramento de reações múltiplas (MRM), foram selecionadas duas diferentes transições íon precursor-íon produto para cada agrotóxico. A metodologia proposta pode ser usada para a determinação de resíduos de agrotóxicos em águas de superfície e potável, em concordância com a Lei n° 518 do Ministério da Saúde, Brasil, e com os parâmetros da União Européia para água potável (Directive 98/83/EC). Abstract in english An analytical method using solid-phase extraction and liquid chromatography coupled to electrospray ionization tandem mass spectrometry (LC-ESI-MS-MS) was developed and validated for the determination and confirmation of eighteen polar pesticides (herbicides, insecticides and fungicides) and two met [...] abolites in water samples. The limits of detection varied between 0.4-40.0 ng L-1 and the limits of quantification between 4.0-100.0 ng L-1. Good linearity with r² > 0.99 for all compounds was obtained. The recovery for 91% of the accuracy experiments varied from 70 to 120%, with RSD below 21% for all. Through multiple reaction monitoring (MRM) two different precursor ion-product ion transitions were selected for each pesticide. The proposed methodology can be used for the convenient and effective determination of pesticide residues in surface and drinking waters in accordance with Law No. 518 ofthe Ministry of Health, Brazil, and the European Union Directive on drinking water quality (98/83/EC).

Adriana, Demoliner; Sergiane S., Caldas; Fabiane P., Costa; Fábio F., Gonçalves; Rosilene M., Clementin; Márcio R., Milani; Ednei G., Primel.

1424-14-01

143

A calorimetric study of carbamate formation  

Energy Technology Data Exchange (ETDEWEB)

Post combustion capture of CO{sub 2} (PCC) is currently one of the leading technologies for the reduction of greenhouse gas emissions from power plants. The most common PCC process is based on the absorption of CO{sub 2} into aqueous amine solutions. CO{sub 2} absorption involves several parallel reactions including hydration of CO{sub 2}; deprotonation of carbonic acid; protonation of the amine; and formation of carbamate. The extent to which each reaction proceeds is dependent on the conditions of absorption (or desorption), as well as the associated equilibrium constants. In this contribution, we use calorimetry and advanced model-based data analysis methods for the unravelling of the thermo-chemistry relevant to PCC and specifically directly determine the reaction enthalpy for carbamate formation. The reaction enthalpies of carbamate formation and amine protonation were measured in dilute aqueous solution at 298 K using isothermal titration calorimetry (ITC) for monoethanolamine (MEA), diethanolamine (DEA), and ammonia (NH{sub 3}). The enthalpy of protonation was also measured for carbonate and bicarbonate. The re-determined protonation constants of the carbonate species and the three amines are in excellent agreement with previously reported results. No measured enthalpies of carbamate formation have been reported previously. For the carbamate formation reaction HCO{sub 3}{sup -} + R'RNH {longleftrightarrow}R'RNCO{sub 2}{sup -}, the following reaction enthalpies were determined: MEA, -29.7 {+-} 0.1 kJ/mol; DEA, -23.7 {+-} 0.9 kJ/mol, and NH{sub 3}, -27.6 {+-} 0.9 kJ/mol. The results are in good agreement with, but much more precise and robust than estimated values reported in the literature.

McCann, N.; Maeder, M.; Hasse, H. [Technical University of Kaiserslautern, Kaiserslautern (Germany)

2011-05-15

144

Analysis of pesticides in fruit, vegetables and cereals using methanolic extraction and detection by LC-MS/MS  

DEFF Research Database (Denmark)

Abstract: A method for analysing carbamates and other relatively polar pesticides by LC–MS–MS with electrospray ionisation has been developed. The method is based on extraction by ultrasonication using a methanolic ammonium acetate–acetic acid buffer. After centrifugation the samples are filtered in Miniprep filter HPLC vials and detected by LC–MS–MS. To compensate for variations in the MS response [13C6]-carbaryl was used as internal standard and matrix-matched pesticide solutions were used as external standards for the quantification. The method has been validated for the matrices apple, avocado, carrot, lettuce, orange, potato and wheat at the spiking levels—0.02; 0.04 and 0.20 mg kg?1. Recoveries were generally in the range 70–120%. Results from participation in three intercomparisons proved the accuracy of the method. As the analytical procedure does not include any concentration or cleanup steps, it is easy and fast to perform, making it applicable for routine analysis in large pesticide monitoring programmes.

Granby, Kit; Andersen, Jens Hinge

2004-01-01

145

Determination of carbamates in edible vegetable oils by ultra-high performance liquid chromatography-tandem mass spectrometry using a new clean-up based on zirconia for QuEChERS methodology.  

Science.gov (United States)

In this study a fast, selective and sensitive multiresidue method based on QuEChERS methodology has been evaluated and validated for the determination of carbamate pesticides, in edible vegetable oils by UHPLC-MS/MS. A new clean-up sorbent, Supel(TM) QuE Z-Sep(+), has been successfully applied in vegetable oil extracts. Z-Sep(+) was compared with other sorbents (i.e. mixture of C18 and PSA) previously used for dispersive solid phase extraction of these matrices, reducing more effectively matrix effects without a significant decrease of analyte recoveries. Matrix effect was studied in different matrices (extra-virgin olive, sunflower, maize, linseed and sesame oil) being ??30?% for most of the studied pesticides. Under optimum conditions, recoveries ranged from 74% to 101%, with relative standard deviations lower than 10%. Limits of quantification ranged from 0.09 to 2.0 µg kg(-1), allowing their determination at the low concentration levels demanding by current legislation. PMID:25059164

Moreno-González, David; Huertas-Pérez, José F; García-Campaña, Ana M; Gámiz-Gracia, Laura

2014-10-01

146

Pesticides chief: '  

SCPinfonet

... Pesticides chief: 'We were not really listening to societal concerns' | EurActiv Intensive farming,pesticides,water policy EU news & policy ... Pesticides: Striking the right balance? Agriculture: In brief Fertilisers: Feeding agriculture's growing needs Eating green? Food, drinks ... VIDEOS Home › Greening the CAP › Interview Pesticides chief: 'We were not really listening to societal concerns' -A + A Published 30 ...Tags specialreport-agriculture specialreport-greening-the-cap specialreport-prods-green-planet cap climate-environment health sustainability Chemicals (REACH) Intensive farming pesticides water policy After years of trying to persuade consumers that their ...

147

Milk contamination by organophosphorus and carbamate residues present in water and animal feedstuff  

Directory of Open Access Journals (Sweden)

Full Text Available In Brazil, the legal requirements regarding the quality control of raw milk are restricted to microbiological, physico-chemical and antimicrobial research. However, pesticides can be detected in milk after exposure of dairy cows to these agents. The present study aimed to search for the presence of organophosphorus (OPP and carbamate (CB pesticides in samples of water and feedstuff supplied to dairy cattle and also in the milk produced by these animals. All samples were analyzed by gas chromatography with nitrogen phosphorus detector (GC-NPD. Residues of OPP were detected in 5 (16.67% out of 30 raw milk samples, all bellow maximum residues limits (MRL. CB residues were not detected in milk. Pesticide residues included in the research were not detected in water samples. Within the 98 samples of the diet’s components of the animals analyzed, OPP were detected in 28 (28.57% samples, CB in 18 (18.37%, while both pesticides were detected in 1 sample (1.02%. In 3 dairy farms it could be noted milk contamination by the same active ingredient of OPP that were detected in animal feed. High levels of animal feed contamination detected in this study raise concerns to the absent control in animal feed production and may represent an important source of milk contamination by these compounds.

Livia Cavaletti Corrêa da Silva

2014-10-01

148

Health Risk Assessment of Pesticide Residues via Dietary Intake of Market Vegetables from Dhaka, Bangladesh  

OpenAIRE

The present study was designed to assess the health risk of pesticide residues via dietary intake of vegetables collected from four top agro-based markets of Dhaka, Bangladesh. High performance liquid chromatography with a photo diode array detector (HPLC-PDA) was used to determine six organophosphorus (chlorpyrifos, fenitrothion, parathion, ethion, acephate, fenthion), two carbamate (carbaryl and carbofuran) and one pyrethroid (cypermethrin) pesticide residues in twelve samples of three comm...

Md. Shakhaoat Hossain; Md. Alamgir Hossain; Md. Abdur Rahman; Md Mainul Islam; Md. Atiqur Rahman, , and; Tanveer Mehedi Adyel

2013-01-01

149

40 CFR 721.7200 - Perfluoroalkyl aromatic carbamate modified alkyl methacrylate copolymer.  

Science.gov (United States)

...2010-07-01 false Perfluoroalkyl aromatic carbamate modified alkyl methacrylate copolymer...721.7200 Perfluoroalkyl aromatic carbamate modified alkyl methacrylate copolymer...generically as perfluoroalkyl aromatic carbamate modified alkyl methacrylate...

2010-07-01

150

Organic Pesticide Ingredients  

Science.gov (United States)

... NPIC Home Page —> Pesticide Ingredients —> Organic Pesticide Ingredients Organic Pesticide Ingredients Organic foods are not necessarily pesticide- ... at npic@ace.orst.edu . Additional Resources on Organic Pesticide Ingredients Understand Organic Labeling - USDA National Organic ...

151

Synthesis, Characterization and Biological Screening of Various O-phenyl-N-aryl Carbamates  

International Nuclear Information System (INIS)

A series of O-phenyl-N-aryl carbamates (3a-i) were synthesized by the reaction of phenyl chloroformate (1) with different aromatic amines (2a-i). The compounds were characterized by IR and 1H-NMR and screened against acetylcholinesterase, butrylcholinesterase and lipoxygenase enzymes. The results revealed that O-phenyl-N-phenyl carbamate (3a) and O-phenyl-N-(3-hydroxyphenyl) carbamate (3e) were active against acetylcholinesterase while O-phenyl-N-benzyl carbamate (3b), O-phenyl-N-(4-hydroxyphenyl) carbamate (3f) and O-phenyl-N-(3-methoxyphenyl) carbamate (3h) exhibited potential inhibitory activity against 5-lipoxygenase. All these carbamates were also assayed for their antimicrobial and hemolytic activities. O-phenyl-N-(2-hydroxyphenyl) carbamate (3d), O-phenyl-N-(4-hydroxyphenyl) carbamate (3f) and O-phenyl-N-(3-methoxyphenyl) carbamate (3h) showed good antimicrobial and hemolytic activity among all the carbamates. (author)

152

Diazeniumdiolated carbamates: A novel class of nitric oxide donors  

OpenAIRE

We report an indirect method for synthesis of previously inaccessible diazeniumdiolated carbamates. Synthesis involves use of previously reported triisopropylsilyloxymethylated isopropylamine diazeniumdiolate (TOM-ylated IPA/NO). These novel diazeniumdiolated carbamate prodrugs upon activation release nitric oxide (NO) similar to their secondary amine counterparts. They are also efficient sources of intracellular NO. These prodrugs may have potential applications as therapeutic NO-donors.

Nandurdikar, Rahul S.; Maciag, Anna E.; Cao, Zhao; Keefer, Larry K.; Saavedra, Joseph E.

2012-01-01

153

Ultrahigh-performance liquid chromatography electrospray ionization Q-Orbitrap mass spectrometry for the analysis of 451 pesticide residues in fruits and vegetables: method development and validation.  

Science.gov (United States)

This paper presents an application of ultrahigh-performance liquid chromatography electrospray ionization quadrupole Orbitrap high-resolution mass spectrometry (UHPLC/ESI Q-Orbitrap MS) for the determination of 451 pesticide residues in fruits and vegetables. Pesticides were extracted from samples using the QuEChERS (quick, easy, cheap, effective, rugged, and safe) procedure. UHPLC/ESI Q-Orbitrap MS in full MS scan mode acquired full MS data for quantification, and UHPLC/ESI Q-Orbitrap Full MS/dd-MS(2) (i.e., data-dependent scan mode) obtained product ion spectra for identification. UHPLC/ESI Q-Orbitrap MS quantification was achieved using matrix-matched standard calibration curves along with the use of isotopically labeled standards or a chemical analogue as internal standards to achieve optimal method accuracy. The method performance characteristics include overall recovery, intermediate precision, and measurement uncertainty evaluated according to a nested experimental design. For the 10 matrices studied, 94.5% of the pesticides in fruits and 90.7% in vegetables had recoveries between 81 and 110%; 99.3% of the pesticides in fruits and 99.1% of the pesticides in vegetables had an intermediate precision of ?20%; and 97.8% of the pesticides in fruits and 96.4% of the pesticides in vegetables showed measurement uncertainty of ?50%. Overall, the UHPLC/ESI Q-Orbitrap MS demonstrated acceptable performance for the quantification of pesticide residues in fruits and vegetables. The UHPLC/ESI Q-Orbitrap Full MS/dd-MS(2) along with library matching showed great potential for identification and is being investigated further for routine practice. PMID:25265038

Wang, Jian; Chow, Willis; Chang, James; Wong, Jon W

2014-10-22

154

Qualitative aspects and validation of a screening method for pesticides in vegetables and fruits based on liquid chromatography coupled to full scan high resolution (Orbitrap) mass spectrometry  

OpenAIRE

The analytical capabilities of liquid chromatography with single-stage high-resolution mass spectrometry have been investigated with emphasis on qualitative aspects related to selective detection during screening and to identification. The study involved 21 different vegetable and fruit commodities, a screening database of 556 pesticides for evaluation of false positives, and a test set of 130 pesticides spiked to the commodities at 0.01, 0.05, and 0.20 mg/kg for evaluation of false negative...

Mol, J. G. J.; Zomer, P.; Koning, A.

2012-01-01

155

Pesticide analysis by MEKC on a microchip with hydrodynamic injection from organic extract.  

Science.gov (United States)

An integrated microchip for monitoring carbamate pesticides in environmental water using continuous flow chemical processes is under development, i. e., the integration of hydrolysis, azo-derivatization, liquid-liquid extraction, electrophoretic separation, and quantification. The separation of the derivatives of four carbamate pesticides (carbaryl, carbofuran, propoxur, and bendiocarb) extracted in the continuous flow of a 1-butanol phase was studied in a silica microchip using micellar EKC. A baseline separation of four pesticide derivatives was achieved on a silica chip using hydrodynamic injection with electroosmotic gating. Detection using a thermal lens microscope showed good linearity in the concentration range of 10(-6 )-10(-5 )M with an LOD of 5 x 10(-7) M, which is superior to that of conventional CE with UV absorption detection at a level of 10(-4) M. PMID:18300211

Smirnova, Adelina; Shimura, Kiyohito; Hibara, Akihide; Proskurnin, Mikhail A; Kitamori, Takehiko

2008-03-01

156

[Hygienic assessment of the use of pesticides in the areas of the Kursk Region].  

Science.gov (United States)

The paper deals with the evaluation of current trends in the application of pesticides and in the detection of their residues in the environmental objects of the Kursk Region. A reduction in the rate of use of pesticides and changes in their structure and range has been established. The amount of organic chlorides and organic phosphates has been decreased while the use of carbamates, heterocyclic compounds, pyrethroids, the derivatives of azoles, avermectins, meonicotinoids, and the derivatives of aryloxyphenoxypropionic acids increased. The degree of environmental danger of the applied pesticides to human health has decreased by 11.2 times in the past 18 years. PMID:16758812

Chernykh, A M

2006-01-01

157

Pesticide Use and Self-Reported Symptoms of Acute Pesticide Poisoning among Aquatic Farmers in Phnom Penh, Cambodia.  

Science.gov (United States)

Organophosphates and carbamates (OPs/CMs) are known for their acetylcholinesterase inhibiting character. A cross-sectional study of pesticide handling practices and self-perceived symptoms of acute pesticide poisoning was conducted using questionnaire-based interviews with 89 pesticide sprayers in Boeung Cheung Ek (BCE) Lake, Phnom Penh, Cambodia. The study showed that 50% of the pesticides used belonged to WHO class I + II and personal protection among the farmers were inadequate. A majority of the farmers (88%) had experienced symptoms of acute pesticide poisoning, and this was significantly associated with the number of hours spent spraying with OPs/CMs (OR = 1.14, CI 95%: 1.02-1.28). The higher educated farmers reduced their risk of poisoning by 55% for each extra personal protective measure they adapted (OR = 0.45, CI 95%: 0.22-0.91). These findings suggest that improving safe pesticide management practices among the farmers and enforcing the effective banning of the most toxic pesticides will considerably reduce the number of acute pesticide poisoning episodes. PMID:21234245

Jensen, Hanne Klith; Konradsen, Flemming; Jørs, Erik; Petersen, Jørgen Holm; Dalsgaard, Anders

2011-01-01

158

Pesticide use and self-reported symptoms of acute pesticide poisoning among aquatic farmers in Phnom Penh, Cambodia  

DEFF Research Database (Denmark)

Organophosphates and carbamates (OPs/CMs) are known for their acetylcholinesterase inhibiting character. A cross-sectional study of pesticide handling practices and self-perceived symptoms of acute pesticide poisoning was conducted using questionnaire-based interviews with 89 pesticide sprayers in Boeung Cheung Ek (BCE) Lake, Phnom Penh, Cambodia. The study showed that 50% of the pesticides used belonged to WHO class I + II and personal protection among the farmers were inadequate. A majority of the farmers (88%) had experienced symptoms of acute pesticide poisoning, and this was significantly associated with the number of hours spent spraying with OPs/CMs (OR = 1.14, CI 95%: 1.02-1.28). The higher educated farmers reduced their risk of poisoning by 55% for each extra personal protective measure they adapted (OR = 0.45, CI 95%: 0.22-0.91). These findings suggest that improving safe pesticide management practices among the farmers and enforcing the effective banning of the most toxic pesticides will considerably reduce the number of acute pesticide poisoning episodes.

Jensen, Hanne Klith; Konradsen, Flemming

2011-01-01

159

Pesticide Use and Self-Reported Symptoms of Acute Pesticide Poisoning among Aquatic Farmers in Phnom Penh, Cambodia  

DEFF Research Database (Denmark)

Organophosphates and carbamates (OPs/CMs) are known for their acetylcholinesterase inhibiting character. A cross-sectional study of pesticide handling practices and self-perceived symptoms of acute pesticide poisoning was conducted using questionnaire-based interviews with 89 pesticide sprayers in Boeung Cheung Ek (BCE) Lake, Phnom Penh, Cambodia. The study showed that 50% of the pesticides used belonged to WHO class I + II and personal protection among the farmers were inadequate. A majority of the farmers (88%) had experienced symptoms of acute pesticide poisoning, and this was significantly associated with the number of hours spent spraying with OPs/CMs (OR = 1.14, CI 95%: 1.02-1.28). The higher educated farmers reduced their risk of poisoning by 55% for each extra personal protective measure they adapted (OR = 0.45, CI 95%: 0.22-0.91). These findings suggest that improving safe pesticide management practices among the farmers and enforcing the effective banning of the most toxic pesticides will considerably reduce the number of acute pesticide poisoning episodes.

Jensen, Hanne Klith; Konradsen, Flemming

2011-01-01

160

Obsolete pesticides  

Science.gov (United States)

Several hundred tons of obsolete pesticide stocks worldwide will pose a threat to humans and the environment until the year 2030 in some regions, unless funding for waste disposal is significantly increased, the United Nations Food and Agriculture Organization (FAO) said in a message directed to donor governments and industry on May 24.“Deadly chemicals are contaminating the soils, groundwater, irrigation, and drinking water,” said Amemayehu Wodageneh, senior expert on obsolete pesticides for FAO. “These ‘forgotten’ stocks are a serious risk, [and] they could cause an environmental tragedy in rural areas and big cities. There is hardly any developing country that is not affected by the hazards of obsolete pesticides

Showstack, Randy

161

Exploration analytique des intoxications par les pesticides Analytical investigation in pesticide intoxication cases  

Directory of Open Access Journals (Sweden)

Full Text Available Du fait du nombre croissant d'intoxications par les pesticides, il est important de développer des méthodes performantes permettant l'identification et le dosage des molécules appartenant à l'ensemble des classes de pesticides. Dans ce but, nous avons développé une méthode de dosage originale et sensible de 61 pesticides dans les matrices biologiques. Cette méthode utilise une procédure d'extraction solide/liquide sur support polymérique (HLB and MCX OASIS®. Le couplage chromatographie en phase gazeuse/spectrométrie de masse (GC/MS est utilisé pour les pesticides volatils (organophosphorés, organochlorés, phtalimides, uraciles et un couplage chromatographie en phase liquide/spectrométrie de masse (LC/MS pour les pesticides polaires et thermolabiles (carbamates, benzimidazoles. L'acquisition est réalisée en mode fragmentométrique (SIM. Les rendements d'extraction varient selon la nature des pesticides dosés, mais restent satisfaisants pour l'ensemble des pesticides. Les limites de détection (LOD et les limites de quantification (LOQ sont réparties entre 2,5 et 20 ng/ml et de 5 à 50 ng/ml. La linéarité a été étudiée entre les différentes LOQ et 1000 ng/ml pour tous les pesticides étudiés. Les résultats sont reproductibles et répétables, avec une bonne précision et une bonne justesse. Des exemples d'intoxication permettent de montrer l'intérêt diagnostique de ces méthodes : deux cas d'intoxication mortelle à l'endosulfan et au carbofuran ; trois autres d'intoxication aiguë au parathion-éthyle, à la bifenthrine et à l'aldicarbe. Considering the huge use of pesticides on a worldwide basis, pesticides account for a small but increasing number of human acute and severe intoxication. However, intoxication cases attributed to pesticides are not always well diagnosed nor documented. In clinical and forensic toxicology, identification and quantification of the toxicants involved are essential for a good diagnosis. Hence, we developed an original and sensitive multiresidue methods for the detection and quantitation, in human biological matrices, of sixty one pesticides of toxicological significance in human. These methods involved rapid solid-phase extraction using new polymeric support (HLB and MCX OASIS® cartridges. Gas chromatography-mass spectrometry (GC/MS was used for volatile (organophosphate, organochlorine, phtalimide, uracil pesticides and liquid chromatography-ionspray®-mass spectrometry (LC/MS for thermolabile and polar pesticides (carbamates, benzimidazoles. Acquisition was performed in the selected ion monitoring (SIM mode. Extraction recovery varied owing to the nature of pesticides but was satisfactory for all. Limits of detection (LODs and limits of quantitation (LOQs ranged respectively from 2.5 to 20 ng/ml and from 5 to 50 ng/ml. An excellent linearity was observed from LOQs up to 1000 ng/ml for all the pesticides studied. The proposed procedures yielded reproducible results with good inter-assay accuracy and precision. A few cases of intoxication are presented to demonstrate the diagnostic interest of these methods : in two cases were determined lethal concentrations of endosulfan and carbofuran ; in three other cases, the procedures helped diagnose intoxication with respectively parathion-ethyl, bifenthrin and aldicarb.

Lacassie Éric

2009-04-01

162

Validação de método para determinação de resíduos de agrotóxicos em tomate: uma experiência laboratorial / Method validation for determination of pesticide residues in tomatoes: a laboratorial experience  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Um modelo de procedimento para validação de método de ensaio para determinação de cinco agrotóxicos (? - HCH, clorotalonil, fenitrotiona, clorpirifós e procimidona em matriz tomate) é demonstrado através da análise cromatográfica. A amostra processada é extraída com 30 mL de acetona e em seguida com [...] 60 mL de uma mistura diclometano: éter de petróleo (1:1). O volume total é centrifugado e a alíquota orgânica é filtrada sob Na2SO4. Um mililitro de extrato orgânico é concentrado e dissolvido em um mililitro de iso-octano. Um microlitro do extrato é analisado no cromatógrafo a gás com detector por captura de elétrons - CG/DCE. Foram avaliados seletividade, linearidade, repetitividade, recuperação e limites de detecção e de quantificação. As recuperações obtidas variaram de 70 a 110%, considerando-se os níveis de adição de agrotóxicos/amostra de 0,02 a 2,50 mg.kg-1. Os limites de detecção do método variaram de 0,004 a 0,006 mg.kg-1 e os de quantificação entre 0,014 e 0,020 mg.kg-1. Abstract in english A validation procedure model of a multiresidue method is presented for chromatographic analyses of five pesticides residues ?-HCH, chlorothalonil, fenitrothion, chlorpyrifos and procymidone applied on tomatoes. The tomatoes were processed and extracted by acetone plus a mixture of dichloromethane:pe [...] troleum benzine (1:1). The volume was centrifuged and was then filtered under Na2SO4. One milliliter of organic extract was concentrated then diluted in isooctane and one microliter was analyzed in the gas chromatograph with electron capture detector - GC/ECD. The parameters evaluated were selectivity, linearity, repeatability, recovery, and limits of detection and quantification. The recovery ranged from 70 to 110% in the concentration range of 0.02 to 2.50 mg.kg-1. The limits of detection ranged from 0.004 to 0.006 mg.kg-1 and the limits of quantification were between 0.014 to 0.02 mg.kg-1.

Maria Helena Wohlers Morelli, Cardoso; Adherlene Vieira, Gouvêa; Armi Wanderley da, Nóbrega; Shirley de Mello Pereira, Abrantes.

2010-05-01

163

Pesticide Poisoning  

Directory of Open Access Journals (Sweden)

Full Text Available In this study, it is aimed that examining the socio-demographic characteristics of the pesticide poisoning cases in Samsun region where the economy mainly relies on agriculture and comparing it to similar studies; thus contributing the country?s data and the possible measures. 60 pesticide poisoning cases consulted OMU Faculty of Medicine between 01.01.2004 and 31.12.2004 are examined and achieved data are analyzed and presented. Of the 60 cases, 35 (58.3% are females and 25 (41.7 are males and the average age is 21.93 ±17.56 (1-63 years. Pesticide poisoning is most common in summer (55.0% and spring (25.0%. It is stated either by the person himself/herself or by his/her relatives that the intake of the toxic substance is accidental in 36 cases (60.0% and suicidal in 24 cases (40.0%. 25 cases (41.7% are poisoned with organic phosphorus pesticides and 12 cases (20.0% with carbamat-pesticides. Consequently, in order to prevent accidental pesticide poisoning, it is necessary to be very careful with pesticide application especially in rural areas. Substances that are least toxic to human and environment, and are licenced and most effective to pests must be used, spraying period must be short, sensitive people, especially children, must be kept away, personal precautions must be taken for the spraying person and pesticides must be kept away from the reach of children and people at risk. [TAF Prev Med Bull. 2007; 6(3: 169-174

Neva Sataloglu

2007-06-01

164

Pesticide Poisoning  

Directory of Open Access Journals (Sweden)

Full Text Available In this study, it is aimed that examining the socio-demographic characteristics of the pesticide poisoning cases in Samsun region where the economy mainly relies on agriculture and comparing it to similar studies; thus contributing the country?s data and the possible measures. 60 pesticide poisoning cases consulted OMU Faculty of Medicine between 01.01.2004 and 31.12.2004 are examined and achieved data are analyzed and presented. Of the 60 cases, 35 (58.3% are females and 25 (41.7 are males and the average age is 21.93 ±17.56 (1-63 years. Pesticide poisoning is most common in summer (55.0% and spring (25.0%. It is stated either by the person himself/herself or by his/her relatives that the intake of the toxic substance is accidental in 36 cases (60.0% and suicidal in 24 cases (40.0%. 25 cases (41.7% are poisoned with organic phosphorus pesticides and 12 cases (20.0% with carbamat-pesticides. Consequently, in order to prevent accidental pesticide poisoning, it is necessary to be very careful with pesticide application especially in rural areas. Substances that are least toxic to human and environment, and are licenced and most effective to pests must be used, spraying period must be short, sensitive people, especially children, must be kept away, personal precautions must be taken for the spraying person and pesticides must be kept away from the reach of children and people at risk. [TAF Prev Med Bull 2007; 6(3.000: 169-174

Neva Sataloglu

2007-06-01

165

Pesticides in Groundwater  

Science.gov (United States)

Pesticides in Groundwater Care to guess how many pounds of pesticides the Nation used in 1964? How about in 1993? If ... they may cause health problems. Pesticides can contaminate groundwater Pesticide contamination of groundwater is a subject of ...

166

Pesticide Safety Tips  

Science.gov (United States)

Pesticide Safety Tips Resources Questions On Pesticides? National Pesticide Information Center (NPIC) 1-800-858-7378 Although pesticides can be useful, they also can be dangerous if used carelessly ...

167

Study on the interaction of catalase with pesticides by flow injection chemiluminescence and molecular docking.  

Science.gov (United States)

The interaction mechanisms of catalase (CAT) with pesticides (including organophosphates: disulfoton, isofenphos-methyl, malathion, isocarbophos, dimethoate, dipterex, methamidophos and acephate; carbamates: carbaryl and methomyl; pyrethroids: fenvalerate and deltamethrin) were first investigated by flow injection (FI) chemiluminescence (CL) analysis and molecular docking. By homemade FI-CL model of lg[(I0-I)/I]=lgK+nlg[D], it was found that the binding processes of pesticides to CAT were spontaneous with the apparent binding constants K of 10(3)-10(5) L mol(-1) and the numbers of binding sites about 1.0. The binding abilities of pesticides to CAT followed the order: fenvalerate>deltamethrin>disulfoton>isofenphos-methyl>carbaryl>malathion>isocarbophos>dimethoate>dipterex>acephate>methomyl>methamidophos, which was generally similar to the order of determination sensitivity of pesticides. The thermodynamic parameters revealed that CAT bound with hydrophobic pesticides by hydrophobic interaction force, and with hydrophilic pesticides by hydrogen bond and van der Waals force. The pesticides to CAT molecular docking study showed that pesticides could enter into the cavity locating among the four subdomains of CAT, giving the specific amino acid residues and hydrogen bonds involved in CAT-pesticides interaction. It was also found that the lgK values of pesticides to CAT increased regularly with increasing lgP, Mr, MR and MV, suggesting that the hydrophobicity and steric property of pesticide played essential roles in its binding to CAT. PMID:24875908

Tan, Xijuan; Wang, Zhuming; Chen, Donghua; Luo, Kai; Xiong, Xunyu; Song, Zhenghua

2014-08-01

168

Rapid Flow Through Immunoassay for CRP Determination Based on Polyethylene Filters Modified with ?-Aminocellulose Carbamate.  

Science.gov (United States)

A novel method for antibody immobilization is discussed and applied in a column based flow through immunoassay system (ABICAP). It is shown that porous polyethylene material can be modified with different ?-aminocellulose carbamates yielding an amino group containing biocompatible support for antibody immobilization. Anti-h CRP antibodies can be bound covalently to the surface via various homobifunctional cross-linkers. The antibody modified filters are validated for the CRP determination in a sandwich ABICAP system. In a 10?min test procedure based on colloidal dye particles, a limit of detection of 5?ng CRP mL(-1) and coefficients of variation of <9.1% are obtained. PMID:25088755

Elschner, Thomas; Scholz, Friedrich; Miethe, Peter; Heinze, Thomas

2014-11-01

169

Radiotracer Approaches to Carbamate Insecticide Toxicology  

International Nuclear Information System (INIS)

Methylcarbamates constitute one of the major groups of insecticides. Many unresolved problems in their toxicology may be readily approached with radiotracer studies. Dimethylcarbamates have been prepared with carbonyl-C14-labelling and methylcarbamates withmethyl-, carbonyl-and ring-labelling utilizing carbon-14. The pharmacological action of these.compounds presumably results from acetylcholinesterase inhibition and may involve carbamylation. Reaction of carbonyl- or methyl-labelled carbamates with purified cholinesterase or other esterases would allow a critical examination of this carbamylation reaction and the ease of spontaneous and induced reactivation or decarbamylation. The physiological significance of cholinesterase inhibition might be examined by administering acetate-C14 and analysis for radiolabelled acetylcholine accumulation in nervous tissue, or by utilizing acetyl-C14-choline as the substrate for in vitro determination of the degree of cholinesterase inhibition in tissues of poisoned animals with minimal dilution of the inhibitors and enzymes during analysis. Some progress has been made with radiolabelled materials in investigating the metabolism of carbamate insecticides. Sevin (1-naphthyl methylcarbamate) has been most extensively studied along with its potential hydrolysis products. The assumption that the metabolism of Sevin involves an initial hydrolysis and then further decomposition of the fragments wn further decomposition of the fragments was not supported by carbon-14 studies. The major detoxification mechanism in mammals, and probably also in insects, results from initial oxidative attack on the carbamate by the microsomes in the presence of reduced nicotinamide-adenine dinucleotide phosphate. Sevin is rapidly metabolized in mammals, but the fate of certain of the fragments has not been resolved. Some of the metabolites appear in the milk of lactating animals. One step in the metabolism appears to be formation of the N-methylol derivative. Preliminary studies on the metabolism of radiolabelled Dimetilan (2-diraethylcarbamyl- 3-methylpyrazolyl-(5)-dimethylcarbamate) and a related compound in cockroaches also indicate that oxidative attack forms N-methyl N-methylol derivatives. Much remains to be done on the relationship of these detoxification reactions to the resistance mechanism, the action of synergists, the selective toxicity in this group of insecticides, and the nature and significance of residues. Metabolism of Sevin following injection into plants is probably also oxidative rather than hydrolytic, but the nature of the products and the enzymatic mechanism have not yet been established. (author)

170

Occurrence of pesticides from coffee crops in surface water  

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Full Text Available The excessive amount of pesticides applied in agricultural areas may reach surface water, thereby contaminating it. Thus, the main purpose of this study was to investigate the presence of pesticides used in a sub-basin headwater with coffee crops, situated in the Dom Corrêa district, Manhuaçu, Minas Gerais. The region of study is a great producer of coffee. Crops occupy steep areas and are situated close to surface water bodies. In this study, four sample collection points were selected in streams as well as a point in the distribution network and two points in the water treatment station (raw and treated water a total of seven points. The samples were collected in rainy and dry seasons. Organochlorines, organophosphates, pyrethroids, carbamates and triazoles pesticides were identified by liquid and gas chromatography analysis with tandem mass spectrometry. The occurrence of pesticides was more evident in the rainy season. A total of 24 distinct pesticides were detected. At least one pesticide was identified in 67% of the samples collected during the rainy season and in 21% of the samples collected during drought. Many pesticides detected in water are not regulated in Brazilian legislation regarding potability.

Márcio Ribeiro Vianna Neto

2013-04-01

171

Potential developmental neurotoxicity of pesticides used in Europe  

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Full Text Available Abstract Pesticides used in agriculture are designed to protect crops against unwanted species, such as weeds, insects, and fungus. Many compounds target the nervous system of insect pests. Because of the similarity in brain biochemistry, such pesticides may also be neurotoxic to humans. Concerns have been raised that the developing brain may be particularly vulnerable to adverse effects of neurotoxic pesticides. Current requirements for safety testing do not include developmental neurotoxicity. We therefore undertook a systematic evaluation of published evidence on neurotoxicity of pesticides in current use, with specific emphasis on risks during early development. Epidemiologic studies show associations with neurodevelopmental deficits, but mainly deal with mixed exposures to pesticides. Laboratory experimental studies using model compounds suggest that many pesticides currently used in Europe – including organophosphates, carbamates, pyrethroids, ethylenebisdithiocarbamates, and chlorophenoxy herbicides – can cause neurodevelopmental toxicity. Adverse effects on brain development can be severe and irreversible. Prevention should therefore be a public health priority. The occurrence of residues in food and other types of human exposures should be prevented with regard to the pesticide groups that are known to be neurotoxic. For other substances, given their widespread use and the unique vulnerability of the developing brain, the general lack of data on developmental neurotoxicity calls for investment in targeted research. While awaiting more definite evidence, existing uncertainties should be considered in light of the need for precautionary action to protect brain development.

Grandjean Philippe

2008-10-01

172

Economic burden of illness from pesticide poisonings in highland Ecuador  

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Full Text Available Active surveillance of acute pesticide poisonings in a potato-growing region of highland Ecuador during 1991-1992 uncovered a rate of 171/100 000, due predominantly to occupational exposures to organophosphate and carbamate pesticides. Occupational exposure among agricultural workers was the most common reason for poisoning (32 male workers and 1 female worker, out of a total of 50 cases. Of these 33 cases, 28 of them reported pesticide application as the work task just prior to poisoning, with over 80% citing the use of World Health Organization Hazard Category I pesticides. The suicide rate of 17.1/100 000 and the overall mortality rate of 20.5/100 000 that we found are among the highest reported anywhere in the world. At the exchange rates prevailing at that time, median costs associated with these poisonings were estimated as follows: public and social security health care direct costs of US$ 9.85/case; private health costs of US$ 8.33/case; and lost-time indirect costs of US$ 8.33/ agricultural worker. Each one of those costs was over five times the daily agricultural wage, which was then about US$ 1.50. Further costing of pesticide poisonings should be carried out in other settings to provide appropriate information for decisions about pesticide use. In addition, integrated pest management should be further evaluated as an appropriate technology to reduce the economic burden of illness from pesticide poisonings in developing countries.

Cole Donald C.

2000-01-01

173

The equilibrium geometry of methyl carbamate  

Science.gov (United States)

The results of theoretical and experimental studies of the structure of the isolated (gas phase) methyl carbamate molecule are reported. The E conformer is calculated to be at least 19 kJ mol -1 above the minimum energy Z conformer. This result is confirmed by the observed band contours seen in the vapour phase IR spectrum. A comparison is made with the results of earlier solution studies which suggest that the E conformer is more stable. Transitions in the amino inversion vibration, seen in the far IR spectrum, show that the amino nitrogen atom has a pyramidal equilibrium geometry, although the lowest energy level lies above the barrier opposing planarity. This is the first simple amide molecule which has been found to have a non-planar equilibrium conformation at nitrogen.

Kydd, R. A.; Rauk, A.

1981-12-01

174

Dog poisoning with furadan 35-ST (carbamate insecticide)  

OpenAIRE

The first case of poisoning of a dog with Furadan 35-ST in Serbia is described. The active ingredient of Furadan 35-ST is carbofuran (2,3-dihydro-2,2-dimethyl-7- benzofuranyl methyl carbamate), a carbamate insecticide, acaricide and nematocide. This highly poisonous substance is classified by the World Health Organisation into Class 1 b and in Serbia into Group 1 of The List of Poisons. Pathological assessment revealed hyperaemia and degenerative and necrot...

Aleksi? Jelena; Mer?ep Drinka; Aleksi? Zoran; Jovanovi? Milijan

2011-01-01

175

Evaluation of carbamate insecticides as chemotherapeutic agents for cancer  

OpenAIRE

Background: Cancer chemotherapy has already been in practice by the use of toxins and some of the specific poisonous compounds of cyanide derivatives. Carbamate insecticides inhibit cellular metabolism including energy, protein, and nucleic acid metabolism, thereby, causing cell regression and death. Aim: Preliminary evaluation of three carbamate insecticides, namely, baygon, carbaryl, and carbofuran as chemotherapeutic agents for cancer is undertaken in the present study. Ma...

Mohd. Amanullah; Hari Babu

2011-01-01

176

Mechanism of action of organophosphorus and carbamate insecticides.  

OpenAIRE

Organophosphorus and carbamate insecticides are toxic to insects and mammals by virtue of their ability to inactivate the enzyme acetylcholinesterase. This review addresses the mechanism of inhibition of acetylcholinesterase by organophosphorus and carbamate esters, focusing on structural requirements necessary for anticholinesterase activity. The inhibition of acetylcholinesterase by these compounds is discussed in terms of reactivity and steric effects. The role of metabolic activation or d...

Fukuto, T. R.

1990-01-01

177

Optimization of detection conditions and single-laboratory validation of a multiresidue method for the determination of 135 pesticides and 25 organic pollutants in grapes and wine by gas chromatography time-of-flight mass spectrometry.  

Science.gov (United States)

This paper describes single-laboratory validation of a multiresidue method for the determination of 135 pesticides, 12 dioxin-like polychlorinated biphenyls, 12 polyaromatic hydrocarbons, and bisphenol A in grapes and wine by GC/time-of-flight MS in a total run time of 48 min. The method is based on extraction with ethyl acetate in a sample-to-solvent ratio of 1:1, followed by selective dispersive SPE cleanup for grapes and wine. The GC/MS conditions were optimized for the chromatographic separation and to achieve highest S/N for all 160 target analytes, including the temperature-sensitive compounds, like captan and captafol, that are prone to degradation during analysis. An average recovery of 80-120% with RSD buprofezin, chlorpyriphos, metalaxyl, and myclobutanil were detected, with an RSD of < 5% (n = 6); the results were statistically similar to previously reported validated methods. PMID:21391504

Dasgupta, Soma; Banerjee, Kaushik; Dhumal, Kondiba N; Adsule, Pandurang G

2011-01-01

178

Correlation between Cholinesterase and Paraoxonase 1 Activities: Case Series of Pesticide Poisoning Subjects  

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Full Text Available Introduction: Acute exposure to pesticide due to suicidal poisoning is the most extensive cause of pesticide exposure, compared with all other causes including agricultural or industrial exposure. Organophosphate (OP and carbamate group of pesticides can inhibit acetylcholinesterase; on the other hand, paraoxonase1 can detoxify organophosphate poisoning by hydrolyzing organophosphate metabolites. Methods: We have compared the serum paraoxonase1 status and cholinesterase activity of subjects who attempted to commit suicide by consuming OP pesticide. Cholinesterase and paraoxonase1 activity were measured spectrophotometrically using butyrylthiocholine and phenyl acetate as substrates, respectively. Results: A positive correlation was found between serum paraoxonase1 activity and cholinesterase activity among pesticide consumed subjects. Conclusion: Our results suggest that subjects with higher paraoxonase1 activity may have a better chance of detoxifying the lethal effect of acute organophosphate poisoning.

S Austin Richard

2013-08-01

179

Physicochemical studies of the carbamate-CO2-solvent system  

International Nuclear Information System (INIS)

The formation of carbamate from CO2 and the various amine solutions has been investigated for the purpose of elucidating the structure of the species generated in the reaction. The amine solutions used were 1 and 2 molar solutions of di-n-butylamine (DNBA) in triethylamine (TEA), pure DNBA and pure TEA. It has been found that the nonaqueous solvent participates in the formation of carbamate in 1 and 2M-DNBA/TEA solutions as a proton acceptor in DNBA-carbamate formation. However, due to the high concentration of the solutions and the basicities of the amines, a significant amount of DNBA which does not form the DNBA-carbamate anion is also found to be participating as a proton acceptor. Pure TEA absorbs only 1/60 of the absorption by pure DNBA. The extent of TEA participation in the CO2-absorption process other than as a proton acceptor in DNBA-carbamate is negligible. The formation of carbamic acid and zwitterion have been found unlikely. 7 tables, 15 figs

180

Effect of pesticide exposure on acetylcholinesterase activity in subsistence farmers from Campeche, Mexico.  

Science.gov (United States)

The authors surveyed agricultural production methods and pesticide use among subsistence farmers (campesinos) in 4 rural communities of Campeche, Mexico. Self-reports of symptoms of poisoning resulting from occupational pesticide exposure were elicited by questionnaire (N = 121), and acetylcholinesterase (AChE) activity during insecticide use was evaluated from blood samples (N = 127). In individuals from 2 of the 4 communities, AChE activity was significantly lower (p < 0.05) than the mean of activity determined for individuals in a reference group. Results of this study show that erythrocyte AChE inhibition provides a good biomarker of exposure to organophosphate pesticides in field studies with human populations. Carbamates, particularly carbofuran, seem to be more associated with exuberant and diversified symptomatology of pesticide exposure than organophosphates. Studies in field communities where both carbamates and organophosphates are suspected to exist should include blood AChE determinations, symptomatology surveys, and socioeconomic questionnaires. The authors recommend that the Mexican National Health Ministry authorities specify additional provisions regarding the use of protective equipment and the adoption of other safety practices during field work, increase information campaigns about the risks of pesticide use and the value of safety practices, and increase programs of medical monitoring and assistance for rural communities dealing with pesticides. PMID:16268118

Rendón von Osten, Jaime; Epomex, Centro; Tinoco-Ojanguren, Rolando; Soares, Amadeu M V M; Guilhermino, Lucia

2004-08-01

181

Behaviour of semipermeable membrane devices in neutral pesticide uptake from waters.  

Science.gov (United States)

The application of semipermeable membrane devices (SPMDs) has been evaluated as a passive sampler for the collection of multiresidue pesticides in continental waters. Seven chlorinated, five organophosphorus, six carbamate, nine pyrethroid and ten other pesticides were tested in order to estimate which compounds can be retained with these devices. The effect of water parameters, such as temperature, pH, ionic strength and organic matter content, were evaluated for their effect on the retention of the pesticides by the SPMDs. Studies of uptake from water were performed in a glass beaker containing 2 L distilled water spiked with 50 ng L-1 of each pesticide investigated. A SPMD was put in the beaker, under turbulent conditions, and analysed after 2 days' extraction. The contents of each SPMD were microwave-assisted-extracted twice with 30 mL hexane-acetone, to 90 degrees C for 10 min, and this was followed by a cleanup based on acetonitrile partitioning and solid-phase extraction. Gas chromatography with tandem mass spectrometry detection was employed for determination of pesticides, and provided low limits of detection from 0.5 to 7 ng per SPMD. Higher absorption rates were observed for pyrethroid, organophosphorus and chlorinated compounds than for carbamates. Pesticide uptake rates were independent of the water composition and decreased at low temperature. PMID:17225999

Esteve-Turrillas, Francesc A; Pastor, Agustín; de la Guardia, Miguel

2007-03-01

182

Pesticide Poisoning  

OpenAIRE

In this study, it is aimed that examining the socio-demographic characteristics of the pesticide poisoning cases in Samsun region where the economy mainly relies on agriculture and comparing it to similar studies; thus contributing the country?s data and the possible measures. 60 pesticide poisoning cases consulted OMU Faculty of Medicine between 01.01.2004 and 31.12.2004 are examined and achieved data are analyzed and presented. Of the 60 cases, 35 (58.3%) are females and 25 (41.7) are ...

Neva Sataloglu; Berna Aydin; Ahmet Turla

2007-01-01

183

Chronic pesticide poisoning from persistent low-dose exposures in Ecuadorean floriculture workers: toward validating a low-cost test battery.  

Science.gov (United States)

Chronic pesticide poisoning is difficult to detect. We sought to develop a low-cost test battery for settings such as Ecuador's floriculture industry. First we had to develop a case definition; as with all occupational diseases a case had to have both sufficient effective dose and associated health effects. For the former, using canonical discriminant analysis, we found that adding measures of protection and overall environmental stressors to occupational category and duration of exposure was useful. For the latter, factor analysis suggested three distinct manifestations of pesticide poisoning. We then determined sensitivity and specificity of various combinations of symptoms and simple neurotoxicity tests from the Pentox questionnaire, and found that doing so increased sensitivity and specificity compared to use of acethylcholinesterase alone--the current screening standard. While sensitivity and specificity varied with different case definitions, our results support the development of a low-cost test battery for screening in such settings. PMID:22550693

Breilh, Jaime; Pagliccia, Nino; Yassi, Annalee

2012-01-01

184

Pesticides in the propolis at São Saulo State, Brazil - doi: 10.4025/actascianimsci.v34i4.15859 Pesticides in the propolis at São Saulo State, Brazil - doi: 10.4025/actascianimsci.v34i4.15859  

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Full Text Available The increasing demand for propolis has caused a raise in its production. However, an increasingly pesticide-dependent agriculture is a great concern with regard to bees, their produce and environmental contamination. Current analysis evaluates the presence of pesticides (organochlorines, organophosphates, pyrethroids, carbamates, herbicides, fungicides and acaricides in samples of propolis from the state of São Paulo, Brazil. Beekeepers from several localities in the state provided samples of propolis (50, which were collected, stored in non-toxic plastic bags and maintained in a freezer for analyses. Possible pesticide residues were examined by gas chromatography method but no pesticide residues were detected in the examined propolis samples. Propolis analyzed in the state of São Paulo did not show any pesticide contamination. The increasing demand for propolis has caused a raise in its production. However, an increasingly pesticide-dependent agriculture is a great concern with regard to bees, their produce and environmental contamination. Current analysis evaluates the presence of pesticides (organochlorines, organophosphates, pyrethroids, carbamates, herbicides, fungicides and acaricides in samples of propolis from the state of São Paulo, Brazil. Beekeepers from several localities in the state provided samples of propolis (50, which were collected, stored in non-toxic plastic bags and maintained in a freezer for analyses. Possible pesticide residues were examined by gas chromatography method but no pesticide residues were detected in the examined propolis samples. Propolis analyzed in the state of São Paulo did not show any pesticide contamination.

Samir Moura Kadri

2012-10-01

185

Derivatization followed by gas chromatography-mass spectrometry for quantification of ethyl carbamate in alcoholic beverages.  

Science.gov (United States)

A sensitive and rapid analytical methodology based on derivatization followed by gas chromatography-mass spectrometry (GC-MS) was developed for the quantitative determination of the toxic contaminant ethyl carbamate (EC, urethane, C(2)H(5)OCONH(2)) in alcoholic samples. EC was extracted using liquid-liquid extraction technique, and then silylated with bis-(trimethylsilyl)trifluoroacetamide, analysed finally by GC-MS. The isopropyl carbamate was used as the internal standard for quantitative analysis of EC in alcoholic samples. In this work, the sample extraction and derivatization reaction conditions were investigated, and the optimal extraction conditions obtained were: pH 9 and solvent of ethyl acetate, and the derivatization conditions were: derivatization reaction temperature of 80°C and time duration of 30 min. With the optimal conditions, the method validations were also studied. In the validation studies, EC exhibited good linearity with a regression coefficient of 0.9999. The limit of detection and limit of quantification were 0.30 and 5.0 ?g/kg, respectively. The precision was less than 8.4%. Finally, the proposed technique was successfully applied to the analysis of EC in 35 kinds of alcoholic samples. The experimental results have demonstrated that the proposed technique is a fast, reliable and low-cost method for determination of EC in alcoholic samples. PMID:22383421

Xu, Xuejiao; Gao, Yihan; Cao, Xiujun; Wang, Xiang; Song, Guoxin; Zhao, Jianfeng; Hu, Yaoming

2012-04-01

186

DESARROLLO Y VALIDACIÓN DE UNA METODOLOGÍA PARA LA DETERMINACIÓN DE PLAGUICIDAS EN CAFÉ VERDE POR CROMATOGRAFÍA DE GASES / METHOD DEVELOPMENT AND VALIDATION FOR THE DETERMINATION OF PESTICIDES IN GREEN COFFEE BY GAS CHROMATOGRAPHY  

Scientific Electronic Library Online (English)

Full Text Available SciELO Colombia | Language: Spanish Abstract in spanish En este estudio se describe la implementación y validación de una metodología multirresiduo para la determinación de plaguicidas organoclorados, organofosforados y piretroides en café verde. Los plaguicidas se extrajeron con una mezcla de solventes acetona-agua (2:1) seguida de una partición con ace [...] tato de etilo- ciclohexano (1:1). Los extractos se limpiaron posteriormente por cromatografía de permeación en gel para eliminar principalmente grasa y cromatografía en minicolumna sobre silicagel para eliminar otros interferentes. La determinación analítica se realizó por cromatografia de gases de alta resolución con inyección splitless pulsada y detección simultánea por microcaptura electrónica (µ-ECD) y nitrógeno-fósforo (NPD) acoplados en paralelo. La metodología es específica, selectiva, precisa y exacta. Los porcentajes de recuperación de la mayoría de los compuestos estuvieron entre 70 y 110% al fortificar con mezcla de plaguicidas entre 0,038 y 1,536 mg/kg con límites de cuantificación entre 0,011 y 0,100 mg/kg. Abstract in english This study describes the implementation and validation of a multiresidue methodology for the determination of organochlorine, organophosphorus and pyrethroids pesticides in green coffee. Pesticides residues were extracted from green samples with an acetone-water (2:1) mixture followed by ethyl aceta [...] te-cyclohexane (1:1) partitioning. The clean up steps include gel permeation chromatography and mini column chromatography using silicagel. Final determination was carried out by high resolution gas chromatography with a pulsed splitless injection mode and simultaneous detection by µ-ECD and NPD coupled in parallel. The methodology is specific, selective precise and accurate. Recoveries of majority of pesticides from spiked samples range from 70 to 110% at fortification levels of 0.038 mg/kg-1.536 mg/kg with limit of quantitation between 0.011 mg/kg and 0.100 mg/kg.

David, Dallos Corredor; Jairo Arturo, Guerrero Dallos.

2005-12-05

187

Total Pesticide Exposure Calculation among Vegetable Farmers in Benguet, Philippines  

International Nuclear Information System (INIS)

This was a cross-sectional study that investigated pesticide exposure and its risk factors targeting vegetable farmers selected through cluster sampling. The sampling size calculated with P=.05 was 211 vegetable farmers and 37 farms. The mean usage of pesticide was 21.35 liters. Risk factors included damaged backpack sprayer (34.7%), spills on hands (31.8%), and spraying against the wind (58%). The top 3 pesticides used were pyrethroid (46.4%), organophosphates (24.2%), and carbamates (21.3%). Those who were exposed to fungicides and insecticides also had higher total pesticide exposure. Furthermore, a farmer who was a pesticide applicator, mixer, loader, and who had not been given instructions through training was at risk of having higher pesticide exposure. The most prevalent symptoms were headache (64.1%), muscle pain (61.1%), cough (45.5%), weakness (42.4%), eye pain (39.9%), chest pain (37.4%), and eye redness (33.8%). The data can be used for the formulation of an integrated program on safety and health in the vegetable industry.

188

40 CFR 180.212 - S-Ethyl cyclohexylethylthio-carbamate; tolerances for residues.  

Science.gov (United States)

... 2010-07-01 false S-Ethyl cyclohexylethylthio-carbamate; tolerances for residues. 180.212 Section 180.212...Tolerances § 180.212 S -Ethyl cyclohexylethylthio-carbamate; tolerances for residues. (a) General....

2010-07-01

189

40 CFR 268.39 - Waste specific prohibitions-spent aluminum potliners; reactive; and carbamate wastes.  

Science.gov (United States)

...specific prohibitions-spent aluminum potliners; reactive; and carbamate wastes. 268.39 Section 268.39 Protection of Environment...specific prohibitions—spent aluminum potliners; reactive; and carbamate wastes. (a) On July 8, 1996, the wastes...

2010-07-01

190

Chlorpropham and phenisopham: phototransformation and ecotoxicity of carbamates in the aquatic environment.  

Science.gov (United States)

In this study, a comparison of two carbamic pesticides, chlorpropham and phenisopham, was carried out in terms of both photodegradability and ecotoxicity. The photochemical behaviour of the two pesticides was investigated under environmental-like conditions (aqueous media, UVB or solar irradiation). The photochemical kinetic parameters were calculated by irradiating 5 × 10(-5) M solutions (H?O-CH?CN, 9?:?1 v/v) using UVB lamps. For chlorpropham and phenisopham similar half-life times (39.0 and 55.0 min) were determined. Irradiation by sunlight leads to longer degradation half-life times (about 3 months), while it is possible to observe the formation of the same photoproducts. The well-known dechlorination reaction to a hydroxyphenylcarbamate was observed for chlorpropham. Phenisopham undergoes photo-Fries reaction to give rearranged products (hydroxybenzamides) and fragmentation products (hydroxyphenylcarbamate and N-ethylaniline). Acute and chronic toxicity tests of pesticides and their photoproducts were performed on organisms from two levels of the freshwater aquatic chain, the anostraca crustacean Thamnocephalus platyurus, the rotifer Brachionus calyciflorus and the alga Pseudokirchneriella subcapitata. The acute results showed that chlorpropham had median lethal concentrations for the crustacean T. platyurus and the rotifer B. calyciflorus of 10.16 and 35.19 mg L(-1), respectively, and phenisopham did not show any acute toxicity as the derivatives up to 10 mg L(-1). The only exception was N-ethylaniline which exhibited an acute LC?? value of 0.46 mg L(-1). Phenisopham was the most toxic in the long term exposure while its five derivatives showed lower chronic potential for rotifers and algae. The same trend was observed for chlorpropham except for rotifers. PMID:24166079

Passananti, Monica; Lavorgna, Margherita; Iesce, Maria Rosaria; DellaGreca, Marina; Criscuolo, Emma; Parrella, Alfredo; Isidori, Marina; Temussi, Fabio

2014-04-01

191

Pesticide residues in cashew apple, guava, kaki and peach: GC-?ECD, GC-FPD and LC-MS/MS multiresidue method validation, analysis and cumulative acute risk assessment.  

Science.gov (United States)

A multiresidue method for the determination of 46 pesticides in fruits was validated. Samples were extracted with acidified ethyl acetate, MgSO4 and CH3COONa and cleaned up by dispersive SPE with PSA. The compounds were analysed by GC-FPD, GC-?ECD or LC-MS/MS, with LOQs from 1 to 8 ?g/kg. The method was used to analyse 238 kaki, cashew apple, guava, and peach fruit and pulp samples, which were also analysed for dithiocarbamates (DTCs) using a spectrophotometric method. Over 70% of the samples were positive, with DTC present in 46.5%, ?-cyhalothrin in 37.1%, and omethoate in 21.8% of the positive samples. GC-MS/MS confirmed the identities of the compounds detected by GC. None of the pesticides found in kaki, cashew apple and guava was authorised for these crops in Brazil. The risk assessment has shown that the cumulative acute intake of organophosphorus or pyrethroid compounds from the consumption of these fruits is unlikely to pose a health risk to consumers. PMID:24996324

Jardim, Andréia Nunes Oliveira; Mello, Denise Carvalho; Goes, Fernanda Caroline Silva; Frota Junior, Elcio Ferreira; Caldas, Eloisa Dutra

2014-12-01

192

Development and validation of method for the determination of organochlorine pesticides and trihalomethanes in the water by HRGC-ECD = Desenvolvimento e validação de método para a determinação de pesticidas organoclorados e trihalometanos em água usando HRGC-ECD  

Directory of Open Access Journals (Sweden)

Full Text Available The development and validation of a simultaneous liquid-liquid extraction method for organochlorine pesticides and trihalomethanes in surface and drinking water by HRGC-ECD is described. The method presents acceptable recovery, with detection ranging from 2.7 to 49.0 ng L-1 for organochlorine pesticides and from 18.0 to 860.0 ng L-1for trihalomethanes. The extraction method also presents excellent linearity for all the analytes, with excellent repeatability. Extraction is simple, fast, and low cost, uses small amounts of solvent and aqueous sample, and is suitable for routine analyses.O presente trabalho trata do desenvolvimento e validação de um método de extração para a determinação simultânea de trihalometanos e pesticidas organoclorados em água superficial e água potável por HRGC-ECD. O método apresenta recuperação aceitável, com limites dedetecção que variam de 2,7 a 49,0 ng L-1 para pesticidas organoclorados e de 18,0 a 860,0 ng L-1 para trihalometanos. O método de extração apresenta também excelente linearidade para todos os analitos e boa repetibilidade. A extração é simples, rápida, de baixo custo, além de utilizar pequenas quantidades de solvente e de amostra aquosa, sendo, portanto, de alta aplicabilidade em análises de rotina.

Maria Isabel Ribeiro Alves

2010-10-01

193

Validation and use of a QuEChERS-based gas chromatographic-tandem mass spectrometric method for multiresidue pesticide analysis in blackcurrants including studies of matrix effects and estimation of measurement uncertainty.  

Science.gov (United States)

A triple quadrupole GC-QqQ-MS/MS method was optimized for multiresidue analysis of over 180 pesticides in blackcurrants. The samples were prepared by using a modified quick, easy, cheap, effective, rugged and safe (QuEChERS) analytical protocol. To reduce matrix co-extractives in the final extract, the supernatant was cleaned up by dispersive-solid phase extraction (dispersive-SPE) with a mixture of sorbents: primary secondary amine (PSA), octadecyl (C18) and graphitized carbon black (GCB). The validation results demonstrated fitness for purpose of the streamlined method. The overall recoveries at the three spiking levels of 0.01, 0.05 and 0.2 mg kg(-1) spanned between 70% and 116% (102% on average) with relative standard deviation (RSD) values between 3% and 19% except for chlorothalonil (23%). Response linearity was studied in the range between 0.005 and 0.5 mg kg(-1). The matrix effect for each individual compound was evaluated through the study of ratios of the slopes obtained in solvent and blackcurrant matrix. The optimized method provided small matrix effect (30%, respectively. Following the application of "top-down" approach, the expanded measurement uncertainty was estimated as being 21% on average (coverage factor k=2, confidence level 95%). If compared with samples of other crops, the analyses of blackcurrants revealed a high percentage of exceedance of the legislative maximum residue levels (MRLs), as well as some instances of the detection of pesticides unapproved on this crop. PMID:24468349

Walorczyk, Stanis?aw

2014-03-01

194

[Formation of ethyl carbamate in umeshu (plum liqueur)].  

Science.gov (United States)

Samples of umeshu, a Japanese plum liqueur made from unripe plums, shochu and crystal sugar, were stored under fluorescent light, in the dark and in the refrigerator. The amount of ethyl carbamate formed in umeshu exposed to light or room temperature was larger than that in the dark or at low temperature. The amount of ethyl carbamate formed in umeshu to which cyanide had been added was larger than that in the absence of added cyanide. Thus, the amount of ethyl carbamate formed in the umeshu was increased by not only light and higher temperature, but also cyanide. Samples of model alcoholic beverages were stored under various conditions using red, yellow and blue cellophanes. The amount of ethyl carbamate formed in the model alcoholic beverage with blue cellophane was larger than in the cases of red and yellow cellophanes. It was found that the amount of ethyl carbamate formed in the model alcoholic beverage was increased by light in the wavelength range of 375-475 nm. PMID:11875819

Suzuki, K; Kamimura, H; Ibe, A; Tabata, S; Yasuda, K; Nishijima, M

2001-12-01

195

Multi-Analyte Separation Methods for HPLC Determination of the Active Ingredients of Pesticides  

International Nuclear Information System (INIS)

The practical quality control of selected pesticides, such as carbamates, organophosphorous compounds, phthalimides, pyrethroids, with HPLC is described. Detailed descriptions are given of materials and methods used, including sample preparation and HPLC operating conditions. The relationship between pH value of the HPLC eluent and the logPow is discussed, illustrated by chromatograms, graphics and tables. The results are also compared with those elaborated by. E. Dudar and presented above. (author)

196

Variation in human herpesvirus susceptibility to enhancement by the pesticide carbaryl.  

OpenAIRE

The ability of various human herpesviruses to be enhanced by the pretreatment of human embryonic lung cells with the pesticide carbaryl (1-naphthyl-N-methyl-carbamate) differs according to the virus tested. Different strains of varicella-zoster virus produced different patterns of susceptibility to enhancement. Laboratory-adapted strains were less sensitive to enhancement than were wild-type strains recently isolated from clinical specimens. The related human herpes simplex viruses types 1 an...

Jerkofsky, M.; Abrahamsen, L. H.

1983-01-01

197

Surveying of Pesticides Commonly on the Markets of Iran in 2009  

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Full Text Available Considering the potential pesticide side effects on environment, their short and long term untoward effects on living creatures, their excessive usage for producing more agricultural products, and also their application to destroy pests of any sort, the present study was carried out to investigate the used amount of common pesticides in Iran markets. A questionnaire was designed. Referring to pesticide selling shops and plants preservations organizations in Tehran and Isfahan, the sufficient data was collected and then categorized regarding the applications and the total amount of used pesticides in a year. The results demonstrated that there were 60 sorts of used pesticides in Iran. They included Organochlorine (10%, Organophosphorus (28.4%, Pyrethroids derivatives (10%, Carbamate derivatives (10%, and others (41.6%. The commonest pesticide used in a year was Organophosphorus and the least one was Organochlorine. The obtained data pointed out that the most common pesticide was Organophosphorus. Given that Organophosphorine compounds are poisonous in living creatures and cause short and long term side effects. It is recommended that responsible authorities provide the necessary information for the aimed groups in terms of the allowable using amount of pesticides, the protection strategies and the pesticides hazards on users.

Rouhullah Dehghani

2011-10-01

198

New screening approach for risk assessment of pesticides in ambient air  

Science.gov (United States)

We present a novel screening approach for inhalation risk assessment of currently used pesticides (CUPs) in ambient air, based on the measurements of pesticide levels in the inhalable fraction of the particulate matter (PM10). Total concentrations in ambient air (gas + particle phases) were estimated using a theoretical model of distribution of semi-volatile organic compounds between the gas and the particulate phase based on the octanol-air partition (Koa) of each pesticide. The proposed approach was used in a pilot study conducted in a rural station in Valencia (Spain) from April through to October 2010. Twenty out of 82 analysed pesticides were detected in average concentrations ranging from 1.63 to 117.01 pg m-3. For adults, children and infants the estimated chronic inhalation risk, expressed as Hazard Quotient (HQ) was <1 for all pesticides. Likewise, the cumulative exposure for detected organophosphorus, pyrethroids and carbamates pesticides, was estimated using as metrics the Hazard Index (HI), which was less than 1 for the three families of pesticides assessed. The cancer risk estimated for the detected pesticides classified as Likely or Possible carcinogens was less than 1.15E-7 for infants. In our opinion, the screening approach proposed could be used in the monitoring and risk assessment of pesticides in ambient air.

Yusà, Vicent; Coscollà, Clara; Millet, Maurice

2014-10-01

199

Optimización y validación de un método de dispersión de matriz en fase sólida para la extracción de plaguicidas organofosforados en hortalizas. / Optimization and validation of a method based on matrix solid-phase dispersion for organophosphorus pesticides in vegetables.  

Scientific Electronic Library Online (English)

Full Text Available SciELO Venezuela | Language: Spanish Abstract in spanish Se optimizó y validó el método de dispersión de matriz en fase sólida (DMFS) para la extracción de plaguicidas organofosforados en hortalizas. Los análisis de plaguicidas se realizaron por cromatografía de gases con un detector fotométrico de flama (FPD) y columna capilar DB-5 la eficiencia de la ex [...] traccio. En las hortalizas (chile verde, tomate bola, tomate saladette, cebolla, calabacita y brócoli) se evaluó calculando los porcentajes de recuperación. Para ello se adicionó una mezcla de los plaguicidas (diazinón, di-systón, metilparatión, malatión, paratión y etión) Se optimizaron las fases de extracción y purificación, donde 0,5 g de sílice como fase de extracción y 2 g de mezcla de carbón-óxido de magnesio-celite (1:2:4) como fase de purificación, produjeron los mayores porcentajes de recuperación de los plaguicidas (61-108%) eluídos con 40 mL de diclorometano, volumen 95% menor al utilizado en el Método Oficial. Los coeficientes de regresión de las curvas de calibración fueron de 0,99 excepto para etión (r = 0,98), los cuales se evaluaron en un intervalo de concentraciones de 50, 100 y 200% de los límites máximos de residuos (LMR). Esta técnica fue aplicada en el análisis de 32 muestras de hortalizas obtenidas de dos centros comerciales locales. Únicamente una muestra de tomate bola presentó niveles de malatión (0,08 µg/g) y paratión (0,06 µg/g), valores por debajo de los LMR. El método de DMFS optimizado y validado en el presente trabajo resultó ser reproducible, exacto y económico-ecológico por su consumo mínimo de disolventes, y pudiera ser utilizado en análisis rutinarios de plaguicidas organofosforados en hortalizas. Abstract in english The objective of this study was the optimization and validation of a method based on matrix solid-phase dispersion (MSPD) for the determination of organophosphorus pesticides in vegetables. This assay was carried out by capillary gas chromatography with Flame Photometric Detection (FPD) and a capill [...] ary column DB5; the recoveries were determined by fortifying six different crops (tomatoes, onions, green pepper, broccoli and squash) with the pesticides studied (diazinon, di-syston, methil-parathion, malathion, parathion, ethion). The optimization of the extraction of these pesticides was achieved using MSPD with diverse extraction and purification phases, where 0.5 g of silica gel on the extraction phase and 2 g of mix of charcoal-magnesium oxide-celite (1:2:4) on the purification phase, eluted using 40 mL dichloromethane, 95% lesser than the used in the official method, were able to extract the pesticides residues. The recoveries were in the range of 61 to 108%. The regression coefficients were 0.99, except for ethion (r = 0.98) over the range between 50, 100 and 200% of maximum residue limits. The applicability of the method to detect and quantify the pesticides studied was demonstrated successfully in 32 vegetables samples obtained from two locals markets. Malathion (0.08 µg/g) and parathion (0.06 µg/g), were detected in only one tomatoes sample, at levels lower than the maximum permits limits. The proposed analytical method could be used as an efficient, fast, cheap and ecological procedure in routine determinations of organophosphorous pesticides in vegetables.

A.I., Valenzuela-Quintanar; R., Armenta-Corral; E., Moreno-Villa; L., Gutiérrez-Coronado; P., Grajeda-Cota; C., Orantes-Arenas..

2006-10-01

200

Illegal Pesticide Products  

Science.gov (United States)

Illegal Pesticide Products Esta página Web está disponible en español Quick Resources Protect your Business Counterfeit Flea and Tick ... Center (NPIC) 1-800-858-7378 Questions on Pesticides? National Pesticide Information Center (NPIC) 1-800-858- ...

201

National Pesticide Information Center  

Science.gov (United States)

National Pesticide Information Center npic@ace.orst.edu 1.800.858.7378 Index A B C D E F ... Your Pest Control Your Pest Integrated Pest Management Pesticide Ingredients Active Ingredients Other/Inert Ingredients Pesticide Products ...

202

Validated High Performance Liquid Chromatographic Method for Analysis of Fenvalerate Pesticide in Chilies by QuEChERS Extraction Cleanup and High Liquid Chromatography  

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Full Text Available Problem statement: Contamination associated with pesticide use has increased as well, adversely impacting the environment and causing human health risks through residues on food. Approach: This study reports the extraction of Fenvalerate (FE in chilies using QuEChERS based on High Performance Liquid Chromatography (HPLC describes a simple, fast and inexpensive method. The chillie was extracted with acetonitrile Aliquots were cleaned-up using Solid Phase Extraction (dSPE, a primary-secondary amine carbon black. Reversed-phased HPlc system with PDA detection was used for the separation identification and quantification of all these analyses using acetonitrile methanol-potassium dehydrogenate phosphate (50:40:10 as mobile phase. Results: Limit of detection of 0.01 µg mL was obtained. Calibration curves that constructed for the analyzes spiked into samples followed linear relationships with good correlation coefficients (R2>0.9944. In this method was found to be precise, specific and accurate for detection and analysis of Fenvalerate in chilies. Conclusion: QuEChERS methods are convenient, rugged methods that simplify extract cleanup, reduce material costs and improve sample throughout. Here we demonstrate the effectiveness of QuEChERS sample cleanup using a multiresidue analysis of pesticide on chilies.

Ahmed A. Altorshani

2010-01-01

203

The use of gamma radiation for removal of pesticides from waste water  

International Nuclear Information System (INIS)

In the present study, a try was made to explain the degradation kinetics due to irradiation of aqueous solutions of some active ingredient pesticides. These pesticides are as follows: one type of triazine herbicide Ametryn and one type of carbamate insecticide (Applaud) and two types of chlorinated organic pesticides, Aldrin and Chlorothalonil. Factors affecting the radiolysis of these pesticides such as the pesticide concentration, irradiation dose, dose rate and pH of the solutions were studied. Ametryn, Applaud, Chlorothalonil and Aldrin insecticides were degraded by gamma radiation and in the case of the chlorinated pesticides hydrochloric acid was detected. The pH effect has proved to vary according to the type of the pesticide and little degradation was observed in alkaline medium, while more degradation of the pesticides in the neutral medium was observed depending on the type of pesticide and on its chemical structure. However, the degradation in the acid medium was even higher. A drop in pH was observed and may be attributed to the degradation of the pesticide molecules to lower molecular weight compounds, such as organic acids. A combined treatment of gamma irradiation and conventional methods was applied and the effect of different additives such as nitrogen and oxygen showed that nitrogen did not enhance the degradation, while an enhancement in the degradation process was observed when oxygen was added. Experiments on the adsorption of these pesticides on on the adsorption of these pesticides on certain polymeric materials and on Granular Activated Carbon (GAC), showed that GAC has the highest adsorption capacity. It may be concluded that the radiation degradation followed by adsorption of the toxic pesticide pollutants and their removal from wastewater down to concentrations not exceeding the maximum permissible concentration (MPC), according to international standards, proved to be better than the conventional methods of purification. (author)

204

Radiochemical neutron activation analysis of selenium using carbamate extraction  

International Nuclear Information System (INIS)

Studies on the solvent extraction of selenium as its carbamate complex form the basis for the application of this system to separate 75Se from irradiated biological matrices in radiochemical neutron activation analysis of this element. Investigation of several sample destruction techniques leads to preferred techniques of oxygen flask combustion for dry materials or acid wet-ashing with nitric and sulphuric acids plus hydrogen peroxide for fresh material. In both cases selenium(IV) was extracted with a toluene solution of carbamate and after ?-counting, the chemical yield was then determined by re-activation of sup(81m)Se. The results were verified by analyses of various SRMs. (author)

205

Rotational Spectrum, Hyperfine Structure, and Internal Rotation of Methyl Carbamate  

Science.gov (United States)

Methyl carbamate, an isomer of glycine, is a possible candidate for interstellar detection. It might be more abundant than glycine and its dipole moment is much larger. Furthermore, using high-level quantum chemical calculations, it is shown that syn methyl carbamate has a lower energy than glycine. The quadrupole hyperfine structure due to 14N has been measured using microwave Fourier transform spectroscopy. The rotational spectrum of the ground vibrational state has been measured from 8 to 240 GHz and accurate spectroscopic constants have been determined for the A internal rotation components of the rotational lines. Finally, the internal rotation splittings have been analyzed.

Bakri, B.; Demaison, J.; Kleiner, I.; Margulès, L.; Møllendal, H.; Petitprez, D.; Wlodarczak, G.

2002-10-01

206

[Survey of pesticide residues in imported frozen vegetables and fruits (1989.4~2008.3)].  

Science.gov (United States)

A survey of pesticide residues in 595 imported frozen products on the Tokyo market from April 1989 to March 2008 was carried out. Forty three kinds of pesticides, including organophosphorus, organochlorine, carbamate, pyrethroid and others, were detected between levels of trace (below 0.01 ppm) and 4.6 ppm from 162 samples. Chlorpyrifos, cypermethrin and omethoate were frequently detected in green vegetables (komatsuna leaf and spinach), cypermethrin and methamidophos were detected in pods and seeds (green soybean and string pea), chlorpropham (CIPC) was detected in potato, and captan and carbaryl were detected in berries (blueberry, raspberry and strawberry). The hydrophilic pesticide methamidophos was detected in flesh of lychee. Residue levels of these pesticides were calculated as between less than 0.5% and 30% of their ADI values according to the daily intake of frozen products. Therefore, these frozen products should be safe when they were eaten in customary amounts. PMID:21515967

Kobayashi, Maki; Ohtsuka, Kenji; Tamura, Yasuhiro; Tomizawa, Sanae; Kamijo, Kyoko; Iwakoshi, Keiko; Kageyama, Yuriko; Nagayama, Toshihiro; Takano, Ichiro

2011-01-01

207

Exposure to Pesticide Mixtures and DNA Damage among Rice Field Workers.  

Science.gov (United States)

Abstract This study describes the use of pesticides mixtures and their potential association with comet assay results in 223 rice field workers in Colombia. Thirty-one pesticides were quantified in blood, serum and urine (15 organochlorines, 10 organophosphorus, 5 carbamates, and ethylenethiourea) and the comet assay was performed. Twenty-four (77,42%) pesticides were present in the workers. The use of the maximum-likelihood factor analysis identified eight different mixtures. Afterwards, robust regressions were used to explore associations between the factors identified and the comet assay. Two groups of mixtures- ?-BHC, HCB and ?-BHC (?: 1,21, 95% CI: 0,33-2,10), and pirimiphos-methyl, malathion, bromophos-methyl, and bromophos-ethyl (?: 11,97, 95% CI: 2,34-21,60)- were associated with a higher percentage of DNA damage and comet tail length, respectively. The findings suggest that exposure to pesticides varies greatly among rice field workers. PMID:24972111

Varona-Uribe, Marcela Eugenia; Torres-Rey, Carlos H; Díaz-Criollo, Sonia; Palma, Ruth M; Narváez, Diana María; Carmona, Sandra Patricia; Briceño, Leonardo; Idrovo, Alvaro Javier

2014-06-27

208

Comparative MO investigation of hindered rotation and thermal decomposition of carbamates and thiocarbamates  

International Nuclear Information System (INIS)

Investigation of hindered rotation in carbamates reveals the high flexibility and ionic character of the C-N bond as compared to common amides. This flexibility decreases in the case of thiocarbamates. The mechanism of activation of carbamates has been explored. Computations have proven the possibility of formation of an intramolecular H-bond in carbamates and thiocarbamates. This intramolecular H-bond is formed immediately after protonation of the carbamate. The possibility of formation of zwitterions as intermediates in the decomposition of carbamic and dithiocarbamic acids is discussed. (Auth.)

209

Examining pyrethroids, carbamates and neonicotenoids in fish, water and sediments from the Indus River for potential health risks.  

Science.gov (United States)

This 3?×?3 factorial study assessed pyrethroids, carbamates and neonicotenoids groups of pesticides in replicated samples of three fish species from low (S1, reference), medium (S2) and heavy (S3) polluted sites receiving agricultural run-offs around the Indus River. Water and sediment samples from the same sites were also analysed for these pesticides by using high-performance liquid chromatography. Out of nine investigated pesticides, only three pesticides (deltamethrin, carbofuran and cypermethrin) were detected in fish and sediment samples. Deltamethrin in Cyprinus carpio ranged from 0.490 to 0.839 ?g/g, mostly exceeding 0.5 ?g/g as the maximum residual limit suggested by FAO-WHO, whereas it ranged from 0.214 to 0.318 ?g/g in the sampled sediments. The carbofuran concentrations were 0.0425-0.066 and 0.613-0.946 ?g/g in Labeo rohita and Channa marulius muscles respectively and 0.069-0.081 ?g/g in the corresponding sediment samples. These values were either higher or lower than the maximum limit (0.1 ?g/g) as suggested by FAO-WHO. Conversely, the cypermethrin concentration ranged from 0.141 to 0.174 in Ch. marulius and 0.183-0.197 ?g/g in sediments which were both below the FAO-WHO maximum limit of 2 ?g/g. No pesticide residues were detected in water from these sampling sites. Most selected physicochemical variables were within the acceptable range of World Health Organization for the water quality for aquatic life. The detected pesticide contents were mostly higher in fish muscles from heavily polluted sites. This is worrying because these pesticides may pose health risks for the fish and people of the study area. However, a preliminary risk assessment indicated that the calculated daily intake of detected pesticides by people consuming fish from the Indus River was low and did not present an immediate risk to the fish-consuming people. This study may be used as a benchmark to determine the safety of fish meat in order to develop intervention strategies to maintain the water quality and to protect the health of fish and fish-consuming people. PMID:25632902

Jabeen, Farhat; Chaudhry, Abdul Shakoor; Manzoor, Sadia; Shaheen, Tayybah

2015-02-01

210

Select Small Core Structure Carbamates Exhibit High Contact Toxicity to “Carbamate-Resistant” Strain Malaria Mosquitoes, Anopheles gambiae (Akron)  

OpenAIRE

Acetylcholinesterase (AChE) is a proven target for control of the malaria mosquito (Anopheles gambiae). Unfortunately, a single amino acid mutation (G119S) in An. gambiae AChE-1 (AgAChE) confers resistance to the AChE inhibitors currently approved by the World Health Organization for indoor residual spraying. In this report, we describe several carbamate inhibitors that potently inhibit G119S AgAChE and that are contact-toxic to carbamate-resistant An. gambiae. PCR-RFLP analysis was used to c...

Wong, Dawn M.; Li, Jianyong; Chen, Qiao-hong; Han, Qian; Mutunga, James M.; Wysinski, Ania; Anderson, Troy D.; Ding, Haizhen; Carpenetti, Tiffany L.; Verma, Astha; Islam, Rafique; Paulson, Sally L.; Lam, Polo C. -h; Totrov, Maxim; Bloomquist, Jeffrey R.

2012-01-01

211

Efficient and Facile Synthesis of ?-Chloroenones Bearing ?-Carbonates or ?-Carbamates  

International Nuclear Information System (INIS)

Efficient synthesis of ?-chloroenones bearing ?-carbonates or ?-carbamates was achieved by rhodium(II)-catalyzed reaction of cyclic diazodicarbonyl compounds with a variety of chloroformates or carbamyl chlorides in good yields. These reactions provided a useful and rapid route to ?-substituted ?-haloenones

212

Dog poisoning with furadan 35-ST (carbamate insecticide  

Directory of Open Access Journals (Sweden)

Full Text Available The first case of poisoning of a dog with Furadan 35-ST in Serbia is described. The active ingredient of Furadan 35-ST is carbofuran (2,3-dihydro-2,2-dimethyl-7- benzofuranyl methyl carbamate, a carbamate insecticide, acaricide and nematocide. This highly poisonous substance is classified by the World Health Organisation into Class 1 b and in Serbia into Group 1 of The List of Poisons. Pathological assessment revealed hyperaemia and degenerative and necrotic changes in the liver, kidneys and heart. In addition, lysis of the nuclei in the motor neurons, loss of tigroid substance and pericellular oedema in the ventral horns of the spinal cord, and acute pancreatitis were found. In addition to the non-specific changes (hyperaemia, degenerative and necrotic changes in the parenchymal organs, the ones in the ventral horns of the spinal cord and acute pancreatitis may lead to carbamate poisoning being suspected. The diagnosis was established on the grounds of toxicological-chemical conformation of carbofuran by means of GC-MS in addition to the macroscopic, microscopic findings in tissue samples taken from the stomach and the liver, which confirmed the suspicion of the dog having been poisoned with the carbamate insecticide. In the current case the results of the diagnostic procedures provided foundations for the initiation of criminal proceedings.

Aleksi? Jelena

2011-01-01

213

EVALUATION OF THE POTENTIAL CARCINOGENICITY OF ETHYL CARBAMATE (URETHANE)  

Science.gov (United States)

Ethyl carbamate is a probable human carcinogen, classified as weight-of-evidence Group B2 under the EPA Guidelines for Carcinogen Risk Assessment (U.S. EPA, 1986a). Evidence on potential carcinogenicity from animal studies is "Sufficient," and the evidence from human studies is "...

214

A Novel Approach for Evaluating Carbamate Mixtures for Dose Additivity  

Science.gov (United States)

Two mathematical approaches were used to test the hypothesis ofdose-addition for a binary and a seven-chemical mixture ofN-methyl carbamates, toxicologically similar chemicals that inhibit cholinesterase (ChE). In the more novel approach, mixture data were not included in the ana...

215

P3 SAR exploration of biphenyl carbamate based Legumain inhibitors.  

Science.gov (United States)

This Letter describes the further development and SAR exploration of a novel series of Legumain inhibitors. Based upon a previously identified Legumain inhibitor from our group, we explored the SAR of the carbamate phenyl ring system to probe the P3 pocket of the enzyme. This led to the identification of a sub-nanomolar inhibitor of Legumain. PMID:24775305

Higgins, Catherine; Bouazzaoui, Samira; Gaddale, Kishore; D'Costa, Zenobia; Templeman, Amy; O'Rourke, Martin; Young, Andrew; Scott, Christopher; Harrison, Tim; Mullan, Paul; Williams, Rich

2014-06-01

216

Acetylcholinesterase Based Detection of Residual Pesticides on Cotton  

Directory of Open Access Journals (Sweden)

Full Text Available This study describes the measurement of bio-electrical signals caused by enzymatic inhibition of acetylcholinesterase (AChE for the detection of organophosphorous and carbamate pesticides which are the strong inhibitors of AChE and prevents its normal function of the rapid removal of acetylcholine (Ach. Biosensor Toxicity Analyzer (BTA was used for the testing and enzyme activity was determined by acetylthiocholine chloride (ATCCl as enzyme substrate. The monitoring of changes in bio-electrical signals caused by the interaction of biological substances and residues were evaluated. Two samples of cotton were analyzed. Cryogenic homogenization was carried out for sample pretreatment and Soxhlet extraction method (SOX was used for extraction. The resulted extracts were concentrated and then injected in the BTA. The method shows reasonable results and can successfully be utilized for the detection of residual pesticides on different types of cotton.

Jiri Militky

2012-02-01

217

The use of gamma radiation for removal of pesticides from waste water  

Science.gov (United States)

In the present study, a try was made to explain the degradation kinetics due to irradiation of aqueous solutions of some active ingredient pesticides. These pesticides are as follows: one type of triazine herbicide Ametryn and one type of carbamate insecticide (Applaud) and two types of chlorinated organic pesticides, Aldrin and Chlorothalonil. Factors affecting the radiolysis of these pesticides such as the pesticide concentration, irradiation dose, dose rate and pH of the solutions were studied. Ametryn, Applaud, Chlorothalonil and Aldrin insecticides were degraded by ?-radiation and in the case of the chlorinated pesticides hydrochloric acid was detected. The pH effect has proved to vary according to the type of the pesticide and little degradation was observed in allkaline medium, while more degradation of the pesticides in the neutral medium was observed depending on the type of pesticide and on its chemical structure. However, the degradation in the acid medium was even higher. A drop in pH was observed and may be attributed to the degradation of the pesticide molecules to lower molecular weight compounds, such as organic acids. A combined treatment of gamma irradiation and conventional methods was applied and the effect of different additives such as nitrogen and oxygen showed that nitrogen did not enhance the degradation, while an enhancement in the degradation process was observed when oxygen was added. Experiments on the adsorption of these pesticides on certain polymeric materials and on Granular Activated Carbon (GAC), showed that GAC has the highest adsorption capacity. It may be concluded that the radiation degradation followed by adsorption of the toxic pesticide pollutants and their removal from wastewater down to concentrations not exceeding the maximum permissible concentration (MPC), according to international standards, proved to be better than the conventional methods of purification.

Dessouki, A. M.; Aly, H. F.; Sokker, H. H.

1999-01-01

218

Comparison Between the Efficiency of Advanced Oxidation Process and Coagulation for Removal Organophosphorus and Carbamat Pesticides  

Directory of Open Access Journals (Sweden)

Full Text Available Background and Objectives: Water pollution by pesticides has adverse effects on the environment and human health, as well .In recent years, advanced oxidation processes, have been gone through to a very high degree for pesticides removal. Poly-Aluminum chloride (PAC used for water treatment, can be effective on pesticides removal. The aim of this research was to study the use of UV/O3 and PAC in the removal of pesticides from drinking water.Materials and Methods: In this descriptive- analytical survey, specific concentrations of pesticides (1,5,10,15,20 ppm;namely Diazinon, Chlorpyrifos, Carbaril were prepared through addition to deionized water. Dichloromethane was used for samples' extraction, samples extracted with Liquid- Liquid & Solid-phase extraction , finally entered bath reactor at pH (6,7,9 .The samples then exposed to UV/O3at contact time of (0.5,1,1.5 and 2 hours . In the PAC pilot , the effects of various concentrations of pesticides, and PAC - ranging (12/24 and 36 ppm were investigated for the efficacy of pesticides removal. All samples analyzed by GC/MS/MS and HPLC. Results: It was found that in UV/O3 reactor, with the rise of pH, decrease in pesticides concentration, and rise of contact time, the efficiency of removal increased too. In the PAC pilot, increase in PAC concentration and decrease in pesticides concentration , both increased the efficiency. Besides, both of the methods showed high efficiencies in the removal of both pesticides,i-e. halogenated Organophosphorus (Chlorpyrifos , non- halogenated Organophosphorus (Diazinon at the degree of over (%80 ; In case of carbamate pesticides (e.g. Carbaril efficiency was over (>%90. One-Way Anova & Two -Way Anova were used to analyze the obtained data.Conclusion: According these results these two methods are suggested for the removal of pesticides from aqueous solutions.

A.R Rahmani

2011-10-01

219

Intoxicación por plaguicidas / Pesticide poisoning  

Scientific Electronic Library Online (English)

Full Text Available SciELO Spain | Language: Spanish Abstract in spanish Los plaguicidas son una de las familias de productos químicos más ampliamente empleadas por el hombre. Se han usado sobre todo para combatir plagas por su acción sobre las cosechas o como vectores de enfermedades transmisibles. Los plaguicidas pueden clasificarse en función de su empleo (insecticida [...] s, fungicidas, herbicidas, raticidas…) o de su familia química (organoclorados, organofosforados, carbamatos, piretoides, compuestos bipiridílicos, sales inorgánicas…). Todos ellos son biocidas lo que implica, habitualmente una alta toxicidad humana que ha sido motivo de preocupación desde mitad del siglo XX debido al amplio e indiscriminado empleo de estos productos. La exposición a los plaguicidas puede tener efectos agudos, crónicos y a largo plazo. Algunos compuestos organoclorados (como el DDT) fueron los primeros en ser empleado en fumigaciones masivas para combatir la malaria y han debido ser prohibidos debido a su capacidad de bioacumulación y persistencia medioambiental. El peligro representado por la generalizada presencia de estos agentes, se ha demostrado en los numerosos episodios de epidemias tóxicas humanas, productoras de alta morbi-mortalidad, descritas por casi todas las familias químicas: insecticidas y fungicidas organoclorados, insecticidas organofosforados y carbamatos, fungicidas organomercuriales y sales inorgánicas. Estos episodios se han producido sobre todo por vía alimentaria y en el terreno profesional. Otras causas de preocupación sanitaria son su capacidad carcinogénica y de ocasionar alteraciones reproductivas. Se presentan las principales características de algunas de las familias más relevantes. Abstract in english Pesticides are one of the families of chemical products most widely used by man. They have been used above all to combat pests because of their effect on harvests and as vectors of transmissible diseases. Pesticides can be classified according to their use (insecticides, fungicides, herbicides, rati [...] cides…) or by their chemical family (organochlorates, organophosphates, carbamates, pyrethroids, Bipyridilium compounds, inorganic salts…). All of them are biocides, which normally implies a high toxicity for humans, which has been a cause for concern since the mid-XX century due to the widespread and indiscriminate use of these products. Exposure to pesticides can have effects that are acute, chronic and long-term. Some organochlorate compounds (such as DDT) were the first to be used in massive fumigations to fight malaria and have had to be banned because of their capacity for bioaccumulation and environmental persistence. The danger represented by the widespread presence of these agents has been demonstrated in numerous episodes of human toxic epidemics, producers of a high morbidity/mortality, described for nearly all chemical families: organochlorate insecticides and fungicides, organophosphate and carbamate insecticides, organomercurial fungicides and inorganic salts. These episodes have above all been caused through the ingestion of foodstuffs and in the occupational field. Other causes of health concern are their carcinogenic capacity and occasional reproductive alterations. The principal characteristics of some of the most relevant families are presented.

A., Ferrer.

220

Agricultural pesticide residues  

International Nuclear Information System (INIS)

Tracer techniques used in the elucidation of the pathways and fate of pesticides in agriculture are reviewed. Such studies include investigating the uptake of labelled pesticides into plants in lysimeter and micro-ecosystem experiments, the translocations of pesticides in the soil, the degradation of pesticides in the soil, the biological availability of soil-applied substances and the bound pesticide residues in the soil. The use of macro- and microautoradiography and double and triple labelling is also described. (U.K.)

221

Histological and Ultrastructural Changes Induced by Two Carbamate Molluscicides on the Digestive Gland of Eobania vermiculata  

Directory of Open Access Journals (Sweden)

Full Text Available Terrestrial snails are destructive agricultural pests as they cause a great damage to vegetables and crops. The present study was designed to evaluate the toxic action of two carbamate molluscicides, methomyl and methiocarb on the digestive gland of the land snail E. vermiculata which is the main site of accumulation and biotransformation of xenobiotics, using topical application and baiting techniques. Sublethal doses and concentrations of both pesticides were applied. After 1, 3, 5, 7 and 14 days of treatment, definite number of snails from each group were chosen and prepared for the aimed studies. Histopathological and ultrastructural alterations in the digestive gland were more obvious after topical application than after baiting technique and methomyl was found to be more toxic than methiocarb. These alterations included hemocyte infiltration,bizarre nuclei that ranged in their degenerative changes from karyolysis to severe karyorrhexis and complete pyknosis, after methomyl treatment and extensive destruction and disorganization of the intertubular connective tissue, after methiocarb treatment. In addition, severe cytoplasmic vacuolization, disruption and reduction of microvilli and formation of surface blabs, increased number of calcium spherules in calcium cells and an aberrant increase in the number of excretory cells containing large number of excretory granules or residual bodies were observed after treatment with both molluscicides. These results are important from the economical point of view since the use of low doses of molluscicides was shown effective, more feasible and less harmful to non-target species like vertebrate animals and human beings.

Sherifa S. Hamed

2007-01-01

222

Fish cholinesterases as biomarkers of sublethal effects of organophosphorus and carbamates in tissues of Labeo rohita.  

Science.gov (United States)

Organophosphates and carbamates are major agrochemicals that strongly affect different neuroenzymes and the growth of various fish species. Here, we study the effect of sublethal concentrations of profenofos and carbofuran on the activity of acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) and the associated health risk in fish. Labeo rohita fingerlings were exposed to three sublethal concentrations of profenofos and carbofuran. The minimum cholinesterase activities in the brain, gills, muscle, kidney, liver, and blood were after exposure to profenofos (0.06 mg/L). The minimum AChE and BuChE activities in the brain, gills, muscle, kidney, liver, and blood were after exposure to carbofuran (0.28 and 0.198 mg/L). Exposure to both types of pesticides affected the functions of these organs, including metabolism and neurotransmission, to various extents at different exposure concentrations. These findings suggest that they are required to be properly monitored in the environment, to reduce their toxic effects on nontarget organisms. PMID:24357265

Ghazala; Mahboob, Shahid; Ahmad, L; Sultana, S; Alghanim, K; Al-Misned, F; Ahmad, Z

2014-03-01

223

Development and validation of a multi-residue analytical methodology to determine the presence of selected pesticides in water through liquid chromatography  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese No presente trabalho uma metodologia analítica é descrita para determinar a presença de multi-residuos de pesticidas utilizados na cultura da cana de açúcar (tebuthiuron, hexazinona, diuron, 2,4-D e ametrina), em fontes de água de abastecimento. Os analitos foram isolados da matriz água, através das [...] seguintes técnicas: extração liquido-liquido (LLE), utilizando diclorometano como solvente; extração em fase sólida (SPE), utilizando C18 como suporte sólido e acetonitrila como solvente para condicionamento da fase e eluição dos analitos; e extração com fluido supercrítico (SFE), utilizando C18 como suporte sólido e CO2 no estado supercrítico como solvente de extração. Análise cromatográfica foi feita por cromatografia liquida de alta eficiência (HPLC) com detector ultravioleta, utilizando acetonitrila/água como fase móvel. Dentre as três técnicas de extração avaliadas, os melhores resultados foram obtidos com extração liquido-liquido e extração em fase sólida. Abstract in english In the present work an analytical methodology is described to determine the presence of multi-residues of selected pesticides used in sugar-cane cultures (tebuthiuron, hexazinone, diuron, 2,4-D and ametrine), in source of drinking water. The analytes were isolated from the water matrix through the f [...] ollowing techniques: liquid-liquid extraction (LLE) using dichloromethane as solvent; solid phase extraction (SPE) using C18 as solid support and acetonitrile as solvent to condition the solid phase and elution of the analytes; and supercritical fluid extraction (SFE) using C18 as solid support and CO2 in supercritical state as extractant solvent. The chromatographic analysis was done by high performance liquid chromatography (HPLC) with an ultraviolet detector and using acetonitrile/water as mobile phase. Among the three evaluated extraction techniques, the best results were obtained with both liquid-liquid extraction and solid phase extraction.

Silvia H. G., Brondi; Fernando M., Lanças.

2005-06-01

224

Carbamate Toxicity and Protective effect of vit. A and vit. E on some biochemicalaspects of male albino rats  

OpenAIRE

The effect of daily oral administration of carbamate (1/10 L.D50) on rats for 30 successive days were studied. The male rats were divided into five groups (control, control + oil, carbamate, carbamate + vit. A and carbamate + vit. E). Each group (except control and control + oil) was daily administrated carbamate (0.012 mg/kg B.wt.). Two groups of carbamate ­ intoxicated animals provided with vit. A (700 mg/kg.B.wt) or vit. E (10 mg/kg.B.wt). Poisoning symptoms were recorded, e.g. unbalanse,...

Samir, A. M. Zaahkouk Eman

2000-01-01

225

Evaluation of the protective effect of garlic oil on hepatic injury induced by pesticides  

International Nuclear Information System (INIS)

The present study was directed to evaluate the effect of repeated daily oral administrations of two pesticides; malathion (organophosphorus) and lannate (carbamate) at dose levels of 27.5 and 3.4 mg/kg body weight, respectively. Garlic oil at a dose of 0.2 ml/kg body weight was given by gavage during pesticides treatment (garlic oil + pesticides) to evaluate its role against the harmful effects of the two selected pesticides in male albino rats. The level of serum 14C-isoleucine (4 ?Ci/100 g body weight) twenty-four hours post administration of malathion or lannate and also garlic oil was studied. Malathion and lannate treatments resulted in significant increase in the activity of alkaline phosphatase, acid phosphatase, gamma glutamyl transferase (GGT), bilirubin, 5-nucleotidase, glucose-6-phosphatase and serum total calcium level. On the other hand, pesticides treatment caused significant decrease in serum inorganic phosphorus. The level of serum 14C-isoleucine twenty-four hours post administration of malathion or lannate and also garlic oil was significantly increased due to pesticides treatment and decreased in case of garlic oil treatment. The protective role of garlic oil was clear to some extent and could ameliorate the activities of some serum enzymes in addition to inorganic phosphorus. The administration of garlic oil to malathion treated animals was more effective in ameliorating the disturbed levels in case of malathion than that occuevels in case of malathion than that occurred with lannate pesticide treatment

226

HUMAN SKIN PERMEATION OF 3-O-ALKYL CARBAMATE PRODRUGS OF NALTREXONE  

OpenAIRE

N-Monoalkyl and N,N-dialkyl carbamate prodrugs of naltrexone (NTX), an opioid antagonist, were synthesized and their in vitro permeation across human skin was determined. Relevant physicochemical properties were also determined. Most prodrugs exhibited lower melting points, lower aqueous solubilities, and higher oil solubilities than NTX. The flux values from N-monoalkyl carbamate prodrugs were significantly higher than those from NTX and N,N-dialkyl carbamates. The melting points of N-monoal...

Vaddi, Haranath K.; Banks, Stan L.; Chen, Jianhong; Hammell, Dana C.; Crooks, Peter A.; Stinchcomb, Audra L.

2009-01-01

227

Carbamate Transport in Carbamoyl Phosphate Synthetase: A Theoretical and Experimental Investigation  

OpenAIRE

The transport of carbamate through the large subunit of carbamoyl phosphate synthetase (CPS) from Escherichia coli was investigated by molecular dynamics and site-directed mutagenesis. Carbamate, the product of the reaction involving ATP, bicarbonate and ammonia, must be delivered from the site of formation to the site of utilization by travelling nearly 40 Å within the enzyme. Potentials of mean force (PMF) calculations along the entire tunnel for the translocation of carbamate indicate tha...

Lund, Liliya; Fan, Yubo; Shao, Qiang; Gao, Yi Qin; Raushel, Frank M.

2010-01-01

228

The Enhanced Carbamate Adsorption of Modified Bentonite with Coscinium  

OpenAIRE

Pesticides daily pollutes soil and water in farmland and environment in ASEAN agricultural developing countries. In this study, pesticide adsorption was studied by bentonite modification, targeting the “organoclay” adsorbent in comparison to native bentonite, which was probably reported to adsorb agricultural pesticide. Commercial bentonite was modified with the berberine containing natural extract from Coscinium fenestratum; the local folk medicine in Thailand. The modified clay by extra...

Tha-in, S.; Dau, H. A.; Dumri, K.

2013-01-01

229

Erythema multiforme-like eruption due to carbamates and thiuram.  

Science.gov (United States)

Report of a case of erythema multiforme-like eruption due to the use of rubber gloves. After several complementary studies, including epicutaneous and skin prick tests, we concluded that the eruption was secondary to sensitization to carbamates and thiuram. The main differential diagnosis in this case was allergic contact dermatitis to latex in natural rubber gloves. This entity is less frequent than might be expected, because it is usually due to intermediate chemical compounds used in rubber manufacturing, such as vulcanization accelerators; among of these latter compounds are thiurams and carbamates. Erythema multiforme-like eruption is a rare manifestation of contact dermatitis. Several cases have been reported, most of which have been due to contact with plants, metals or topical non-steroidal anti-inflammatory drugs. Its mechanism is still unclear, but it seems to be a type IV hypersensitivity reaction. PMID:16750123

Leis-Dosil, Vicente M; Campos-Domínguez, Minia; Zamberk-Majlis, Pamela E; Suárez-Fernández, Ricardo M; Lázaro-Ochaita, Pablo

2006-01-01

230

Molybdenum(V) dimeric complexes with dialkyl carbamates  

International Nuclear Information System (INIS)

Syntheses are reported for a number of novel oxo and sulphido bridged molybdenum(V) complexes with N-methyl-N-cyclohexyl carbamate and N,N-dicyclohexyl carbamate as ligands, and we have compared these complexes with the molybdenum(V) complexes with dialkyldithiocarbamates as ligands. These complexes were identified by IR and electronic spectra, magnetic susceptibility and analytical data, and were assigned the formulae [Mo2O3(LL)4], [Mo2O4(LL)2], [Mo2O2S2(LL)2] and [Mo2O3S(LL)2]. IR and electronic spectra of these compounds are sensitive to substitution of sulphur atoms into the bridge system. It is suggested that the low magnetic moments observed are due, at least in part, to intramolecular metal-metal interactions. (author)

231

Fully acetylated carbamate and hypotensive thiocarbamate glycosides from Moringa oleifera.  

Science.gov (United States)

Six new and three synthetically known glycosides have been isolated from the leaves of Moringa oleifera, employing a bioassay-directed isolation method on the ethanolic extract. Most of these compounds, bearing thiocarbamate, carbamate or nitrile groups, are fully acetylated glycosides, which are very rare in nature. Elucidation of the structures was made using chemical and spectroscopic methods, including 2D NMR techniques. Thiocarbamates showed hypotensive activity. PMID:7766390

Faizi, S; Siddiqui, B S; Saleem, R; Siddiqui, S; Aftab, K; Gilani, A H

1995-03-01

232

B-type esterases in the snail Xeropicta derbentina: An enzymological analysis to evaluate their use as biomarkers of pesticide exposure  

Energy Technology Data Exchange (ETDEWEB)

The study was prompted to characterize the B-type esterase activities in the terrestrial snail Xeropicta derbentina and to evaluate its sensitivity to organophosphorus and carbamate pesticides. Specific cholinesterase and carboxylesterase activities were mainly obtained with acetylthiocholine (K{sub m} = 77.2 mM; V{sub max} = 38.2 mU/mg protein) and 1-naphthyl acetate (K{sub m} = 222 mM, V{sub max} = 1095 mU/mg protein) substrates, respectively. Acetylcholinesterase activity was concentration-dependently inhibited by chlorpyrifos-oxon, dichlorvos, carbaryl and carbofuran (IC50 = 1.35 x 10{sup -5}-3.80 x 10{sup -8} M). The organophosphate-inhibited acetylcholinesterase activity was reactivated in the presence of pyridine-2-aldoxime methochloride. Carboxylesterase activity was inhibited by organophosphorus insecticides (IC50 = 1.20 x 10{sup -5}-2.98 x 10{sup -8} M) but not by carbamates. B-esterase-specific differences in the inhibition by organophosphates and carbamates are discussed with respect to the buffering capacity of the carboxylesterase to reduce pesticide toxicity. These results suggest that B-type esterases in X. derbentina are suitable biomarkers of pesticide exposure and that this snail could be used as sentinel species in field monitoring of Mediterranean climate regions. - Characterization of the B-type esterases in the terrestrial snail Xeropicta derbentina in order to evaluate pesticide exposure.

Laguerre, Christel [Universite d' Avignon et des Pays de Vaucluse, UMR 406 UAPV/INRA, F-84914 Avignon (France); INRA, Laboratoire de Toxicologie Environnementale, UMR 406 UAPV/INRA, F-84914 Avignon (France); Sanchez-Hernandez, Juan C. [Laboratory of Ecotoxicology, Faculty of Environmental Science, University of Castilla-La Mancha, Avda. Carlos III s/n, 45071 Toledo (Spain); Koehler, Heinz R. [Animal Physiological Ecology, University of Tuebingen, Konrad-Adenauer-Strasse 20, D-72072 Tuebingen (Germany); Triebskorn, Rita [Animal Physiological Ecology, University of Tuebingen, Konrad-Adenauer-Strasse 20, D-72072 Tuebingen (Germany); Steinbeis-Transfer Center for Ecotoxicology and Ecophysiology, Blumenstrasse 13, D-72108 Rottenburg (Germany); Capowiez, Yvan [INRA, Unite PSH, F- 84914 Avignon (France); Rault, Magali [Universite d' Avignon et des Pays de Vaucluse, UMR 406 UAPV/INRA, F-84914 Avignon (France); INRA, Laboratoire de Toxicologie Environnementale, UMR 406 UAPV/INRA, F-84914 Avignon (France); Mazzia, Christophe [Universite d' Avignon et des Pays de Vaucluse, UMR 406 UAPV/INRA, F-84914 Avignon (France); INRA, Laboratoire de Toxicologie Environnementale, UMR 406 UAPV/INRA, F-84914 Avignon (France)], E-mail: mazzia@avignon.inra.fr

2009-01-15

233

Calculation of the IR spectra of toluene-2,4-bis (methyl) carbamate  

Science.gov (United States)

The IR spectra of toluene-2,4-bis (methyl) carbamate and its duetero analogue in the crystalline state and in the melt were studied. The absorption curves of the free and associated toluene-2,4-bis (methyl) carbamate molecules were compared with experimental IR spectra. The characteristic toluene-2,4-bis (methyl) carbamate and methyl- N-methyl carbamate clusters were revealed. The IR spectra for the two most stable molecular conformations were compared. The origin of the multiplet structure of bands in the experimental IR spectra of polyurethanes was discussed. The results obtained can be used for the analysis of the chemical and physical transformations in urethanes and polyurethanes.

Furer, V. L.

1999-02-01

234

pesticides workshop presentation niea jake gibson  

SCPinfonet

...Rosetta Mullan and Ray Thomas Pesticides monitoring 2004 –present Pesticides Workshop, Loughry College 15th March...5?g/l total pesticides) in potable water • DWD pesticide...pesticide failures from Derg WTW • Pesticides were MCPA and Mecoprop, widely...

235

Application of ACD/LABS 12 program for determination of conditions for experimental membrane extraction of pesticides  

Directory of Open Access Journals (Sweden)

Full Text Available This paper analyzes the conditions for membrane extraction of pesticides using ACD / LABS 12 program. The program contains a large database of more than 2000 compounds and their ionized species, for determining the pKa, further analysis includes 600 new compounds confirmed by Hammett’s equation, which gives more precise values for logD and solubility. The 16 pesticides of different classes (organophosphates, carbamates, carbamidas, neonicotinoids etc. and polarities commonly used in Serbia were examined. The program is used to calculate logD, pKa and solubility at different pH values for the mixture of pesticides. Based on the calculated values, the conditions for the extraction of pesticides in water using two-phase liquid-liquid membrane extraction were optimized.

?or?evi? J.

2010-01-01

236

Evaluation of Four Bio fertilizers for Bioremediation of Pesticide contaminated Soil  

International Nuclear Information System (INIS)

Experiments were conducted to asses the ability of mixed populations of microorganisms which produced as a bio fertilizers by the General Organization of Agriculture Fund, Ministry of Agriculture, Egypt (phosphoren, microbien, cerealin and azospirillum) to degrade five selected pesticides representing different classes including organophosphate, carbamate and chlorinated organic compounds. There were differences in rates of biotransformation, suggesting the selective induction of certain metabolic enzymes. Inoculation of soil incorporated with malathion, fenamiphos, carbaryl, aldicarb and dieldrin, resulted in ca. 80-90% removal of malathion and fenamiphos within 8 days, carbaryl and aldicarb within 11-15 days respectively. Dieldrin removal occurred slowly within 2 months. These data suggest that bioremediate may act as potential candidates for soil inoculation to bioremediate pesticide contaminated soil. The production of Co2 (soil respiration ) was stimulated by some pesticides. In samples with microbien, an about 2 times higher Co2 production was measured

237

Common Pesticide Questions  

Science.gov (United States)

... Y Z Home Health & Safety Human Health Animal Health Safe Use Practices Food Safety Pest Control Identify Your Pest Learn About Your Pest Control Your Pest Integrated Pest Management Pesticide Ingredients Active Ingredients Other/Inert Ingredients Pesticide Products ...

238

METHOD FOR MEASURING BASE/NEUTRAL AND CARBAMATE PESTICIDES IN PERSONAL DIETARY SAMPLES  

Science.gov (United States)

Dietary uptake may be a significant pathway of exposure to contaminants. As such,dietary exposure assessments should be considered an important part of the total exposure assessment process. The objective of this work was to develop reliable methods that are applicable to a wide ...

239

Pesticide exposure - Indian scene  

International Nuclear Information System (INIS)

Use of pesticides in India began in 1948 when DDT was imported for malaria control and BHC for locust control. India started pesticide production with manufacturing plant for DDT and benzene hexachloride (BHC) (HCH) in the year 1952. In 1958, India was producing over 5000 metric tonnes of pesticides. Currently, there are approximately 145 pesticides registered for use, and production has increased to approximately 85,000 metric tonnes. Rampant use of these chemicals has given rise to several short-term and long-term adverse effects of these chemicals. The first report of poisoning due to pesticides in India came from Kerala in 1958 where, over 100 people died after consuming wheat flour contaminated with parathion. Subsequently several cases of pesticide-poisoning including the Bhopal disaster have been reported. Despite the fact that the consumption of pesticides in India is still very low, about 0.5 kg/ha of pesticides against 6.60 and 12.0 kg/ha in Korea and Japan, respectively, there has been a widespread contamination of food commodities with pesticide residues, basically due to non-judicious use of pesticides. In India, 51% of food commodities are contaminated with pesticide residues and out of these, 20% have pesticides residues above the maximum residue level values on a worldwide basis. It has been observed that their long-term, low-dose exposure are increasingly linked to human health effects such as immune-suppression, hormone disruption, diminished intellion, hormone disruption, diminished intelligence, reproductive abnormalities, and cancer. In this light, problems of pesticide safety, regulation of pesticide use, use of biotechnology, and biopesticides, and use of pesticides obtained from natural plant sources such as neem extracts are some of the future strategies for minimizing human exposure to pesticides

240

Leaching and degradation of pesticides in groundwater layers  

International Nuclear Information System (INIS)

To date, most of the published data on pesticides and soil describe the fate of environmental contaminants in the upper soil layers, where low transportation, high adsorption and high microbial degradation occur. In contrast, few data are available for groundwater layers (to a depth of 5 m) with filtration media such as sand or stony layers. Laboratory testing systems were developed that allow examinations to be carried out under conditions that are close to natural. These include original sands and stones from the relevant groundwater filtration areas, original water from the same areas, and measurement of the velocity of water migrations. The temperature and pH were determined and exact analyses of the sand quality and particle size were made prior to the experiments. To produce accurate data on leaching and adsorption, and to identify the degradation products more easily, 14C labelled pesticides were applied. To determine the column characteristics, tritium labelled water was used. The following 12 pesticides were investigated: the carbamate insecticide, carbofuran; chlorinated hydrocarbons, lindane, DDT and DDE; phosphoric acid esters, chlorpyrifos, diazinon, malathion and parathion; phenylurea herbicides, diuron and monolinuron; the triazine herbicide, terbutylazine; and the novel chloronicotinyl insecticide, imidacloprid. Although the recovery data of the individual pesticides were similar in the eluates of the two different sand types, in most cases e two different sand types, in most cases the elution curves differed significantly. The different degradation rates and procedures for the same pesticide were clearly shown by the significantly different concentration values. Concerning elution and degradation, the behaviour of the chemicals differed, even if they belonged to the same class of bioactive compound. Furthermore, the behaviour of the same chemical differed in different types of sand. Because of the low transportation velocity, and the subsequent long retention times of the pesticides in the sand medial, microbial degradation (metabolisms) can also take place. (author). 11 refs, 3 figs, 6 tabs

241

Exposure to Pesticides in Residents or the Banks of the Río Bogotá (Suesca and the Capitan Fish  

Directory of Open Access Journals (Sweden)

Full Text Available Objective: Considering the high use of pesticides in Colombia and the harmful effects resulting fromexposure to these substances on human health and the environment, a study for the determinationof biomarkers of exposure and effect of pesticides in population of the banks of the Río Bogotáin Suesca, the levels of pesticides in river water samples taken in the same city and in samples offish, “Capitán de la Sabana” (Eremophylus mutisii caught in this area. Materials and methods:We measured for organophosphates, carbamates, dithiocarbamates and organochlorines. We alsoexplored through a survey of occupational exposure to pesticides in the population and knowledgeand use of personal protective measures in their work. Additionally, we explored the habit offishing for captain and consumption in the diet of the inhabitants of the riverbank. Results: Theresults show the presence of organochlorine and organophosphorus pesticides in the river and infish tissue and organochlorine and ethylene thiourea in human biological samples. Participated inthe study workers directly exposed to pesticides, highly toxic handlers, most know and use personalprotective measures and industrial hygiene. Conclusions: Pollution such as pesticides in the upperbasin of Bogotá that affects wildlife and coastal populations. Best action is necessary to promoteenvironmental care, protection and self-care of persons using pesticides in the area.

Rodríguez-Forero Adriana

2012-03-01

242

Pesticides halve bees'  

SCPinfonet

...Pesticides halve bees' pollen gathering ability, research shows | EurActiv source of protein that bees have, and it is vital for ... cap,bees,pesticides EU news & policy debates- across languages - en fr Click here for EU news »x Search this ... VIDEOS Home › Agriculture & Food › News Pesticides halve bees' pollen gathering ability, research shows [fr] -A + A Published 04 ...February 2014 1 comment Tags bees, pesticides Bumblebees exposed to controversial pesticides collect just half the pollen they would otherwise harvest, according to new ...

243

tert-Butyl N-benzyl-N-(4-methyl-2-pyridyl)carbamate  

OpenAIRE

In the crystal structure of the title compound, C18H22N2O2, the pyridine ring makes dihedral angles of 83.71?(6) and 9.2?(1)° with the phenyl ring and the carbamate plane, respectively. The phenyl ring and the carbamate plane are nearly perpendicular to one another, with a dihedral angle of 87.17?(7)°.

Pierre Koch; Dieter Schollmeyer; Stefan Laufer

2008-01-01

244

Water templated hydrogen-bonded network of pyridine amide appended carbamate in solid state  

Science.gov (United States)

The pyridine amide appended carbamates 1 and 2 have been synthesized and their hydrogen-bonded self-assemblies in solid state have been described. The self-association pattern is dependent on the nature the anchored group of the carbamate moiety and influenced by water inclusion. Inclusion of water molecule gives a ladder type hydrogen bonded assemblies with cavities.

Ghosh, Kumaresh; Adhikari, Suman; Fröhlich, Roland

2006-03-01

245

COMPARISON OF ACUTE NEUROBEHAVIORAL EFFECTS OF N-METHYL CARBAMATE INSECTICIDES.  

Science.gov (United States)

The acute neurobehavioral and cholinesterase (ChE)-inhibiting effects of N-methyl carbamate insecticides have not been systematically compared. We evaluated five carbamates - carbaryl (CB), propoxur (PP), oxamyl (OM), methomyl (MM), and methiocarb (MC). Adult male Long-Evans ra...

246

Occupational allergic contact dermatitis from xanthates and carbamates in mining processes.  

Science.gov (United States)

The objective of this article is to describe allergic contact dermatitis from sodium isopropyl xanthate, potassium amyl xanthate, and carbamates in a geotechnician, to discuss possible cross-reactions, and to report the widespread use of carbamates and mercaptobenzothiazole in mining processes. PMID:14744410

Sasseville, Denis; Muhn, Channy Y; Al-Sowaidi, Mowza

2003-09-01

247

Selective Conversion of O-Succinimidyl Carbamates to N-(O-Carbamoyl)-Succinmonoamides and Ureas  

Science.gov (United States)

N-monoalkyl-O-succinimidyl carbamates reached with primary and secondary amines to produce ureas. However, N,N-dialkyl-O-succinimidyl-carbamates reacted with primary and secondary amines, via succinimide ring opening, to afford N-(O-carbamoyl)-succinmonoamide derivatives. This ring opening trend w...

248

Understanding Pesticide Behaviour At The Catchment Scale  

Science.gov (United States)

Pesticides in stream flow at the outlet of a 142ha catchment in Eastern England (Col- worth, Bedfordshire), have been monitored since October 1999. About 50% of the total catchment is directly controlled within one farm and a rotation of wheat, oil seed rape, grass, linseed, beans and peas is grown. The data from this catchment are being used to investigate the performance of the USDA SWAT contaminant transport pack- age at the catchment scale. Three years of stream flow and climate data are available with a useful set of pesticide application and detection data. Following calibration and validation of the hydrology of the catchment, pesticide modelling was carried out for tebuconazole, terbutryn, and terbuthylazine. This paper reports on the results of a sen- sitivity analysis of the model, and the final calibrated pesticide component. Analysis of the results obtained show that the timing and decay of predicted pesticide concen- trations are correct. It is therefore recommended that SWAT can be used as a tool to understand pesticide behaviour at the catchment scale.

Kannan, N.; White, S. M.; Worrall, F.; Pendlington, D.; Groves, S.

249

Mapping ecological risk of agricultural pesticide runoff.  

Science.gov (United States)

A screening approach for the EU-scale is introduced and validated that predicts pesticide runoff and related ecological risk for aquatic communities in small agricultural streams. The approach is based on the runoff potential (RP) of stream sites, by a spatially explicit calculation based on pesticide use, precipitation, topography, land use and soil characteristics in the near-stream environment. The underlying simplified model complies with the limited availability and resolution of data at larger scales. RP is transformed to ecological risk by means of a runoff-response relationship between RP and invertebrate community composition that results from a large-scale investigation and considers the influence of landscape-mediated recovery pools. Community composition is expressed as abundance of SPEcies At Risk (SPEAR) i.e. species that are potentially affected by pesticides because of physiological sensitivity to organic pollutants and ecological traits. The SPEAR concept was applied because it provides powerful community descriptors that are independent of habitat parameters and support comparison of pesticide effects between different geographical regions. Raster maps for the EU before the 2004 enlargement indicate that ecological risk from pesticide runoff is potentially low for streams in 34% of the grid cells with non-irrigated arable land (mostly northern countries, predicted effects at southern countries, predicted effects at >90% of the streams per cell). Field investigations showed that the screening approach produced appropriate estimates of ecological risk from pesticide runoff for selected regions in Finland, France and Germany. PMID:17689592

Schriever, Carola Alexandra; Liess, Matthias

2007-10-01

250

Health Risk Assessment of Pesticide Residues via Dietary Intake of Market Vegetables from Dhaka, Bangladesh  

Directory of Open Access Journals (Sweden)

Full Text Available The present study was designed to assess the health risk of pesticide residues via dietary intake of vegetables collected from four top agro-based markets of Dhaka, Bangladesh. High performance liquid chromatography with a photo diode array detector (HPLC-PDA was used to determine six organophosphorus (chlorpyrifos, fenitrothion, parathion, ethion, acephate, fenthion, two carbamate (carbaryl and carbofuran and one pyrethroid (cypermethrin pesticide residues in twelve samples of three common vegetables (tomato, lady’s finger and brinjal. Pesticide residues ranged from below detectable limit (<0.01 to 0.36 mg/kg. Acephate, chlorpyrifos, ethion, carbaryl and cypermethrin were detected in only one sample, while co-occurrence occurred twice for fenitrothion and parathion. Apart from chlorpyrifos in tomato and cypermethrin in brinjal, all pesticide residues exceeded the maximum residue limit (MRL. Hazard risk index (HRI for ethion (10.12 and carbaryl (1.09 was found in lady’s finger and tomato, respectively. Rest of the pesticide residues were classified as not a health risk. A continuous monitoring and strict regulation should be enforced regarding control of pesticide residues in vegetables and other food commodities.

Md. Shakhaoat Hossain

2013-02-01

251

Resíduos de pesticidas em águas superficiais de área de nascente do Rio São Lourenço-MT: validação de método por extração em fase sólida e cromatografia líquida / Pesticide residues in surface waters at the headwaters of São Lourenço River-MT, Brazil: validation of a method using solid-phase extraction and liquid chromatography  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese [...] Abstract in english A multiresidue method using HPLC/DAD for the determination of fourteen pesticides in water based on SPE, using SDVB (styrene divynilbenzene copolymer) as adsorbent was validated. Recoveries from 61 to 120%, relative standard deviation between 2 and 15% and detection limits from 0.07 to 0.75 µg L-1 w [...] ere obtained. It was applied to 66 surface water samples collected in a degraded area at the headwaters of São Lourenço river, Mato Grosso, Brazil. Eight pesticides were detected in concentrations ranging from 0.15 to 35.25 µg L-1. Considering ecotoxicological data, carbendazim and carbofuran may represent a risk to aquatic organisms. These results draw attention to the contamination of this vulnerable degraded area.

Anna Carolina Araújo, Ribeiro; Eliana Freire Gaspar de Carvalho, Dores; Ricardo Santos Silva, Amorim; Carolina, Lourencetti.

252

Resíduos de pesticidas em águas superficiais de área de nascente do Rio São Lourenço-MT: validação de método por extração em fase sólida e cromatografia líquida Pesticide residues in surface waters at the headwaters of São Lourenço River-MT, Brazil: validation of a method using solid-phase extraction and liquid chromatography  

Directory of Open Access Journals (Sweden)

Full Text Available A multiresidue method using HPLC/DAD for the determination of fourteen pesticides in water based on SPE, using SDVB (styrene divynilbenzene copolymer as adsorbent was validated. Recoveries from 61 to 120%, relative standard deviation between 2 and 15% and detection limits from 0.07 to 0.75 µg L-1 were obtained. It was applied to 66 surface water samples collected in a degraded area at the headwaters of São Lourenço river, Mato Grosso, Brazil. Eight pesticides were detected in concentrations ranging from 0.15 to 35.25 µg L-1. Considering ecotoxicological data, carbendazim and carbofuran may represent a risk to aquatic organisms. These results draw attention to the contamination of this vulnerable degraded area.

Anna Carolina Araújo Ribeiro

2013-01-01

253

Evaluation of carbamate insecticides as chemotherapeutic agents for cancer  

Directory of Open Access Journals (Sweden)

Full Text Available Background: Cancer chemotherapy has already been in practice by the use of toxins and some of the specific poisonous compounds of cyanide derivatives. Carbamate insecticides inhibit cellular metabolism including energy, protein, and nucleic acid metabolism, thereby, causing cell regression and death. Aim: Preliminary evaluation of three carbamate insecticides, namely, baygon, carbaryl, and carbofuran as chemotherapeutic agents for cancer is undertaken in the present study. Materials and Methods: The toxicity of carbamates on squamous cell carcinoma was assessed in-vitro using dye binding tests. Cells were grown in microtitration ELISA plates, as adherent cultures, for six hours, and then exposed to the drugs for 2, 4, 8, and 12 hours, and finally stained with neutral red, to assess the viable cell number, and with methylene blue for the determination of protein in the monolayer. Optical density was read in an ELISA reader. Statistical Analysis: The data obtained during the experiment was subjected to statistical analysis by using the student ?t? test. Results: The results indicated that the percentage of the viable cell number reduced with an increase in the time of exposure of the drugs. Exposure of the tumor cells to the drugs for 12 hours detached them completely from the wells, and hence, all the cells were washed out. Exposure of the drugs prior to the establishment of the culture in-vitro resulted in the non-formation of the monolayer in the wells. Conclusions: Among the three drugs studied, the survival percent was least with carbaryl treatment followed by baygon, and with carbofuran treatment it was almost near to control group.

Mohd. Amanullah

2011-01-01

254

Determination of biocides and pesticides by on-line solid phase extraction coupled with mass spectrometry and their behaviour in wastewater and surface water  

International Nuclear Information System (INIS)

This study focused on the input of hydrophilic biocides into the aquatic environment and on the efficiency of their removal in conventional wastewater treatment by a mass flux analysis. A fully automated method consisting of on-line solid phase extraction coupled to LC-ESI-MS/MS was developed and validated for the simultaneous trace determination of different biocidal compounds (1,2-benzisothiazoline-3-one (BIT), 3-Iodo-2-propynylbutyl-carbamate (IPBC), irgarol 1051 and 2-N-octyl-4-isothiazolinone (octhilinone, OIT), carbendazim, diazinon, diuron, isoproturon, mecoprop, terbutryn and terbutylazine) and pharmaceuticals (diclofenac and sulfamethoxazole) in wastewater and surface water. In the tertiary effluent, the highest average concentrations were determined for mecoprop (1010 ng/L) which was at comparable levels as the pharmaceuticals diclofenac (690 ng/L) and sulfamethoxazole (140 ng/L) but 1-2 orders of magnitude higher than the other biocidal compounds. Average eliminations for all compounds were usually below 50%. During rain events, increased residual amounts of biocidal contaminants are discharged to receiving surface waters. - Incomplete removal of biocides and pesticides during wastewater treatment.

255

Determination of biocides and pesticides by on-line solid phase extraction coupled with mass spectrometry and their behaviour in wastewater and surface water  

Energy Technology Data Exchange (ETDEWEB)

This study focused on the input of hydrophilic biocides into the aquatic environment and on the efficiency of their removal in conventional wastewater treatment by a mass flux analysis. A fully automated method consisting of on-line solid phase extraction coupled to LC-ESI-MS/MS was developed and validated for the simultaneous trace determination of different biocidal compounds (1,2-benzisothiazoline-3-one (BIT), 3-Iodo-2-propynylbutyl-carbamate (IPBC), irgarol 1051 and 2-N-octyl-4-isothiazolinone (octhilinone, OIT), carbendazim, diazinon, diuron, isoproturon, mecoprop, terbutryn and terbutylazine) and pharmaceuticals (diclofenac and sulfamethoxazole) in wastewater and surface water. In the tertiary effluent, the highest average concentrations were determined for mecoprop (1010 ng/L) which was at comparable levels as the pharmaceuticals diclofenac (690 ng/L) and sulfamethoxazole (140 ng/L) but 1-2 orders of magnitude higher than the other biocidal compounds. Average eliminations for all compounds were usually below 50%. During rain events, increased residual amounts of biocidal contaminants are discharged to receiving surface waters. - Incomplete removal of biocides and pesticides during wastewater treatment.

Singer, Heinz; Jaus, Sylvia; Hanke, Irene; Lueck, Alfred; Hollender, Juliane [Eawag, Swiss Federal Institute of Aquatic Science and Technology, Ueberlandstrasse 133, CH-8600 Duebendorf (Switzerland); Alder, Alfredo C., E-mail: alfredo.alder@eawag.c [Eawag, Swiss Federal Institute of Aquatic Science and Technology, Ueberlandstrasse 133, CH-8600 Duebendorf (Switzerland)

2010-10-15

256

Toxic effects of pesticide mixtures at a molecular level: Their relevance to human health  

International Nuclear Information System (INIS)

Highlights: ? Toxic effects of pesticide mixtures can be independent, dose addition or interaction. ? Metabolic interactions involve inhibition or induction of detoxifying enzymes. ? Organophosphates can potentiate pyrethroid, carbaryl and triazine toxicity. ? Synergism occurs when two active pesticides elicit greater than additive toxicity. ? Endocrine disruptors have the potential for additivity rather than synergism. - Abstract: Pesticides almost always occur in mixtures with other ones. The toxicological effects of low-dose pesticide mixtures on the human health are largely unknown, although there are growing concerns about their safety. The combined toxicological effects of two or more components of a pesticide mixture can take one of three forms: independent, dose addition or interaction. Not all mixtures of pesticides with similar chemical structures produce additive effects; thus, if they act on multiple sites their mixtures may produce different toxic effects. The additive approach also fails when evaluating mixtures that involve a secondary chemical that changes the toxicokinetics of the pesticide as a result of its increased activation or decreased detoxification, which is followed by an enhanced or reduced toxicity, respectively. This review addresses a number of toxicological interactions of pesticide mixtures at a molecular level. Examples of such interactions include the postulated mechanisms for the potentiation of pyrethroid, carbaryl and triazine herbicides toxicity by organophosphates; how the toxicity of some organophosphates can be potentiated by other organophosphates or by previous exposure to organochlorines; the synergism between pyrethroid and carbamate compounds and the antagonism between triazine herbicides and prochloraz. Particular interactions are also addressed, such as those of pesticides acting as endocrine disruptors, the cumulative toxicity of organophosphates and organochlorines resulting in estrogenic effects and the promotion of organophosphate-induced delayed polyneuropathy

257

Ecological risk of pesticide residues in the British Columbia environment: 1973-2012.  

Science.gov (United States)

An updated ecological risk assessment was conducted to re-evaluate and review the overall risk of pesticide residues to certain aquatic life. The focus was the impact on offsite non-target, freshwater organisms of pesticide operational sprays in British Columbia from 1973 until 2012. The values of risk quotients for pesticides of selected indicator organisms were determined to measure the effect. When compared with organophosphorus, carbamate, and other miscellaneous pesticides, this risk assessment analysis suggests that the historical use of persistent and highly toxic organochlorine pesticides posed, and continue to pose, a deleterious ecological risk. The risk is both short-term acute and long-term sub-acute, chronic toxicity to offsite, non-target aquatic invertebrates and juvenile salmonid fish. Data indicated that these organisms were, and remain, subjected to harmful effects of pesticide residues to varying degrees. Most vulnerable were, and also are, benthic organisms inhabiting bottom sediments. This substrate is the natural sink for persistent pesticide residues, predominantly organochlorine pesticides from historical use, as well as dioxins, furans, and polycyclic aromatic hydrocarbons from wood preservatives, and other sources. Environment Canada's main aquatic protection strategy was a 10 metre no-treatment buffer zone, augmented with an additional appropriate setback along shorelines of fishery and wildlife resource-sensitive water bodies. This study discusses why this guideline was necessary, useful and effective, but was only partially successful. The physical-chemical properties of pesticide residues, from either an individual compound or different compounds in combination, also influence the nature of biological impacts on non-target, aquatic organisms. Few studies have been conducted in British Columbia aquatic environments to investigate the significance of this aspect. PMID:23431973

Wan, Michael T

2013-01-01

258

Biofilters to treat the pesticides wastes from spraying applications: results after 4 years of study.  

Science.gov (United States)

Biofilters were developed in order to eliminate or reduce the quantity of pesticides from rinsing and cleaning waters of sprayers. Biofilters consist in 1, 2 or 3 plastic containers of 1 m3 placed in a vertical pile and containing a substrate elaborated from a homogenised mixture of local soil, chopped straw and compost able to absorb and degrade the pesticides. Biofilters are installed near the area for cleaning and rinsing the sprayer and the waste waters are pumped into the system. Since 2002, a pilot study is carried out in Belgium in order to evaluate the efficacy of these systems. Twenty pilot systems were installed since 2002 until 2004 in several farms, agricultural technical centres or schools and in a municipal maintenance service. The efficacy of the biofilters was studied for several chemical classes of herbicides (sulfonylurea, aryloxyalcanoic acids, chloroacetanilides), insecticides (pyrethroids, carbamates) and fungicides (dicarboximides, phenylamides, triazoles and strobilurines). The balance of the inputs and the outputs of the pesticides was determined by monitoring the elutes. The degradation kinetic of pesticides into the substrate was evaluated by analysing the pesticides into the substrate. The microbiological activity of the substrate was also evaluated by measuring respiration and some indirect parameters like dry matter content, Kjeldahl nitrogen content, organic carbon content and biological oxygen demand (BOD). Results obtained until now after four years of experiments have showed an overall good efficacy (retention) of pesticides by the biofilter and a high degradation rate for the majority of pesticides. Biofilters permit to reduce highly the quantity of pesticides from rinsing and cleaning waters of sprayers and contribute significantly to the reduction of the contamination of surface water. Biofilters are now registered by the Ministry of Agriculture and Environment of the Walloon Region in Belgium and are recommended to pesticides users. PMID:17390768

Pigeon, O; De Vleeschouwer, C; Cors, F; Weickmans, B; Huyghebaert, B; Planchon, V; Pussemier, L; Culot, M

2006-01-01

259

tert-Butyl N-(thiophen-2-yl)carbamate  

OpenAIRE

In the title compound, C9H13NO2S, the dihedral angle between the thiophene ring and the carbamate group is 15.79?(14)°. In the crystal structure, intramolecular C—H...O interactions in tandem with the tert-butyl groups render the packing of adjacent molecules in the [001] direction nearly perpendicular [the angle between adjacent thiophene rings is 74.83?(7)°]. An intermolecular N—H...O hydrogen bond gives rise to a chain extending along [001]. The crystal st...

Hsu, Gene C.; Singer, Laci M.; Cordes, David B.; Michael Findlater

2013-01-01

260

Characterizing pesticide sorption and degradation in macro scale biopurification systems using column displacement experiments  

International Nuclear Information System (INIS)

The efficiency of biopurification systems to treat pesticide-contaminated water was previously studied in microcosms. To validate the obtained results, macrocosm systems were set-up. Four pesticides (linuron, isoproturon, bentazone, and metalaxyl) were continuously applied to ten different organic substrate mixes. Retention of the pesticides was similar and in some cases slightly lower in the macrocosms compared to the microcosms. Differences in retention between the different mixes were however minimal. Moreover, the classification of the retention strength of the pesticides was identical to that observed in microcosms: linuron > isoproturon > metalaxyl > bentazone. Monod kinetics were used to describe delayed degradation, which occurred for isoproturon, metalaxyl and bentazone. No breakthrough of linuron was observed, thus, this pesticide was appointed as the most retained and/or degraded pesticide, followed by isoproturon, metalaxyl and bentazone. Finally, most of the matrix mixes efficient in degrading or retaining pesticides were mixes containing dried cow manure. - Transport of pesticides in macrocosm containing organic substrates

261

Influence of pesticide regulation on acute poisoning deaths in Sri Lanka  

Directory of Open Access Journals (Sweden)

Full Text Available OBJECTIVES: To assess in a developing Asian country the impact of pesticide regulation on the number of deaths from poisoning. These regulations, which were implemented in Sri Lanka from the 1970s, aimed to reduce the number of deaths - the majority from self-poisoning - by limiting the availability and use of highly toxic pesticides. METHODS: Information on legislative changes was obtained from the Ministry of Agriculture, national and district hospital admission data were obtained from the Sri Lanka Health Statistics Unit, and individual details of deaths by pesticide poisoning were obtained from a manual review of patients' notes and intensive care unit records in Anuradhapura. FINDINGS: Between 1986 and 2000, the total national number of admissions due to poisoning doubled, and admissions due to pesticide poisoning increased by more than 50%. At the same time, the case fatality proportion (CFP fell for total poisonings and for poisonings due to pesticides. In 1991_92, 72% of pesticide-induced deaths in Anuradhapura were caused by organophosphorus (OP and carbamate pesticides - in particular, the WHO class I OPs monocrotophos and methamidophos. From 1991, the import of these pesticides was reduced gradually until they were banned for routine use in January 1995, with a corresponding fall in deaths. Unfortunately, their place in agricultural practice was taken by the WHO class II organochlorine endosulfan, which led to a rise in deaths from status epilepticus - from one in 1994 to 50 in 1998. Endosulfan was banned in 1998, and over the following three years the number of endosulfan deaths fell to three. However, at the end of the decade, the number of deaths from pesticides was at a similar level to that of 1991, with WHO class II OPs causing the most deaths. Although these drugs are less toxic than class I OPs, the management of class II OPs remains difficult because they are, nevertheless, still highly toxic, and their toxicity is exacerbated by the paucity of available facilities. CONCLUSION: The fall in CFP amidst a rising incidence of self-poisoning suggests that Sri Lanka's programmes of pesticide regulation were beneficial. However, a closer inspection of pesticide-induced deaths in one hospital revealed switching to other highly toxic pesticides, as one was banned and replaced in agricultural practice by another. Future regulation must predict this switching and bear in mind the ease of treatment of replacement pesticides. Furthermore, such regulations must be implemented alongside other strategies, such as integrated pest management, to reduce the overall pesticide availability for self-harm.

Roberts Darren M.

2003-01-01

262

Assessing Health Risks from Pesticides  

Science.gov (United States)

Assessing Health Risks from Pesticides Este Web page está disponible en español Questions on Pesticides? Contact the National Pesticide Information Center ( ... of Toxicity Tests EPA Requires for Human Health Risk Assessments EPA evaluates studies conducted over different periods ...

263

B-type esterases in the snail Xeropicta derbentina: an enzymological analysis to evaluate their use as biomarkers of pesticide exposure.  

Science.gov (United States)

The study was prompted to characterize the B-type esterase activities in the terrestrial snail Xeropicta derbentina and to evaluate its sensitivity to organophosphorus and carbamate pesticides. Specific cholinesterase and carboxylesterase activities were mainly obtained with acetylthiocholine (K(m)=77.2 mM; V(max)=38.2 mU/mg protein) and 1-naphthyl acetate (K(m)=222 mM, V(max)=1095 mU/mg protein) substrates, respectively. Acetylcholinesterase activity was concentration-dependently inhibited by chlorpyrifos-oxon, dichlorvos, carbaryl and carbofuran (IC50=1.35x10(-5)-3.80x10(-8) M). The organophosphate-inhibited acetylcholinesterase activity was reactivated in the presence of pyridine-2-aldoxime methochloride. Carboxylesterase activity was inhibited by organophosphorus insecticides (IC50=1.20x10(-5)-2.98x10(-8) M) but not by carbamates. B-esterase-specific differences in the inhibition by organophosphates and carbamates are discussed with respect to the buffering capacity of the carboxylesterase to reduce pesticide toxicity. These results suggest that B-type esterases in X. derbentina are suitable biomarkers of pesticide exposure and that this snail could be used as sentinel species in field monitoring of Mediterranean climate regions. PMID:18775593

Laguerre, Christel; Sanchez-Hernandez, Juan C; Köhler, Heinz R; Triebskorn, Rita; Capowiez, Yvan; Rault, Magali; Mazzia, Christophe

2009-01-01

264

Ban of Neonicotinoid Pesticides  

OpenAIRE

European Union (EU) has banned the use of three pesticides: clothianidin, thiamethoxam and imidacloprid in bee attractive crops. These pesticides all belong to a pesticide group called neonicotinoids, and they are believed to be a contributing factor in the declining bee population. The ban was enforced in EU the 1st of December 2013. Neonicotinoids (clothianidin and thiamethoxam) are an important part of the control of pests in oilseed rape production in Danish agriculture. The neonicotinoid...

Inthasen, Prapaporn

2014-01-01

265

The ground and first excited torsional states of methyl carbamate  

Science.gov (United States)

A global fit within experimental accuracy of microwave and millimeter-wave transitions in the ground and first excited torsional states of methyl carbamate (H 2NC(O)OCH 3) is presented. The data set consisting of 995 vt = 0 and 731 vt = 1 transition frequencies combines 1544 new measurements from Kharkov with previously published vt = 0 microwave lines. In this study the so-called "rho axis method" that treats simultaneously both A and E species of the ground and first excited torsional states is applied to the methyl carbamate data set for the first time. The final fit requires only 32 parameters to achieve a unitless weighted standard deviation for the whole fit of 0.89 for a total of 1726 transitions with rotational quantum numbers up to J ? 20 and Ka ? 10. The barrier to internal rotation of the methyl group obtained in this study, V3 = 359.141(24) cm -1, is in good agreement with previously published values but more accurate.

Ilyushin, V.; Alekseev, E.; Demaison, J.; Kleiner, I.

2006-11-01

266

New water-soluble carbamate ester derivatives of resveratrol.  

Science.gov (United States)

Low bioavailability severely hinders exploitation of the biomedical potential of resveratrol. Extensive phase-II metabolism and poor water solubility contribute to lowering the concentrations of resveratrol in the bloodstream after oral administration. Prodrugs may provide a solution-protection of the phenolic functions hinders conjugative metabolism and can be exploited to modulate the physicochemical properties of the compound. We report here the synthesis and characterization of carbamate ester derivatives of resveratrol bearing on each nitrogen atom a methyl group and either a methoxy-poly(ethylene glycol)-350 (mPEG-350) or a butyl-glucosyl promoiety conferring high water solubility. Ex vivo absorption studies revealed that the butyl-glucosyl conjugate, unlike the mPEG-350 one, is able to permeate the intestinal wall. In vivo pharmacokinetics confirmed absorption after oral administration and showed that no hydrolysis of the carbamate groups takes place. Thus, sugar groups can be attached to resveratrol to obtain soluble derivatives maintaining to some degree the ability to permeate biomembranes, perhaps by facilitated or active transport. PMID:25275336

Mattarei, Andrea; Carraro, Massimo; Azzolini, Michele; Paradisi, Cristina; Zoratti, Mario; Biasutto, Lucia

2014-01-01

267

New Water-Soluble Carbamate Ester Derivatives of Resveratrol  

Directory of Open Access Journals (Sweden)

Full Text Available Low bioavailability severely hinders exploitation of the biomedical potential of resveratrol. Extensive phase-II metabolism and poor water solubility contribute to lowering the concentrations of resveratrol in the bloodstream after oral administration. Prodrugs may provide a solution—protection of the phenolic functions hinders conjugative metabolism and can be exploited to modulate the physicochemical properties of the compound. We report here the synthesis and characterization of carbamate ester derivatives of resveratrol bearing on each nitrogen atom a methyl group and either a methoxy-poly(ethylene glycol-350 (mPEG-350 or a butyl-glucosyl promoiety conferring high water solubility. Ex vivo absorption studies revealed that the butyl-glucosyl conjugate, unlike the mPEG-350 one, is able to permeate the intestinal wall. In vivo pharmacokinetics confirmed absorption after oral administration and showed that no hydrolysis of the carbamate groups takes place. Thus, sugar groups can be attached to resveratrol to obtain soluble derivatives maintaining to some degree the ability to permeate biomembranes, perhaps by facilitated or active transport.

Andrea Mattarei

2014-10-01

268

Retinal degeneration and other eye disorders in wives of farmer pesticide applicators enrolled in the agricultural health study.  

Science.gov (United States)

Retinal degeneration is the leading cause of visual impairment in older adults. An association between retinal degeneration and fungicide use was observed previously among farmer pesticide applicators in the Agricultural Health Study, a large study of farm families from Iowa and North Carolina. The objective of this investigation was to determine whether wives of these farmer pesticide applicators were at increased risk of retinal degeneration. Self-reported cross-sectional data obtained via questionnaire between 1993 and 1997 from 31,173 wives were used. Associations of specific pesticides and groups of pesticides based on function (fungicides, herbicides, insecticides, and fumigants) or chemical structure (organophosphates, organochlorines, and carbamates) with eye disorders were evaluated using logistic and hierarchical logistic regression analyses. Self-reported retinal degeneration was associated with the wife's fungicide use (odds ratio = 1.9, 95% confidence interval: 1.2, 3.1) after adjustment for age and state of residence. Specific fungicides that appeared to drive this association were maneb or mancozeb and ziram. No associations between pesticide use and other eye disorders were found. Although these findings for retinal degeneration are based solely on self-reported disease, they are consistent with those reported for farmer pesticide applicators. These findings suggest that exposure to some fungicides and other pesticides may increase the risk of retinal degeneration and warrant further investigation. PMID:15901622

Kirrane, Ellen F; Hoppin, Jane A; Kamel, Freya; Umbach, David M; Boyes, William K; Deroos, Anneclaire J; Alavanja, Michael; Sandler, Dale P

2005-06-01

269

Proteome-wide reactivity profiling identifies diverse carbamate chemotypes tuned for serine hydrolase inhibition.  

Science.gov (United States)

Serine hydrolases are one of the largest and most diverse enzyme classes in Nature. Inhibitors of serine hydrolases are used to treat many diseases, including obesity, diabetes, cognitive dementia, and bacterial and viral infections. Nonetheless, the majority of the 200+ serine hydrolases in mammals still lack selective inhibitors for their functional characterization. We and others have shown that activated carbamates, through covalent reaction with the conserved serine nucleophile of serine hydrolases, can serve as useful inhibitors for members of this enzyme family. The extent to which carbamates, however, cross-react with other protein classes remains mostly unexplored. Here, we address this problem by investigating the proteome-wide reactivity of a diverse set of activated carbamates in vitro and in vivo, using a combination of competitive and click chemistry (CC)-activity-based protein profiling (ABPP). We identify multiple classes of carbamates, including O-aryl, O-hexafluoroisopropyl (HFIP), and O-N-hydroxysuccinimidyl (NHS) carbamates that react selectively with serine hydrolases across entire mouse tissue proteomes in vivo. We exploit the proteome-wide specificity of HFIP carbamates to create in situ imaging probes for the endocannabinoid hydrolases monoacylglycerol lipase (MAGL) and ?-? hydrolase-6 (ABHD6). These findings, taken together, designate the carbamate as a privileged reactive group for serine hydrolases that can accommodate diverse structural modifications to produce inhibitors that display exceptional potency and selectivity across the mammalian proteome. PMID:23701408

Chang, Jae Won; Cognetta, Armand B; Niphakis, Micah J; Cravatt, Benjamin F

2013-07-19

270

Responses of B-esterase enzymes in oysters (Crassostrea gigas) transplanted to pesticide contaminated bays form the Ebro Delta (NE, Spain).  

Science.gov (United States)

Marine bivalves such as oysters are widely used as bioindicators to monitor marine coastal pollution. This study aimed to use B-esterase activity responses in oysters (Crassostrea gigas) cultured in Ebro Delta bays to monitor environmental effects of pesticides. The B esterases investigated were acetylcholinesterase, propionylcholinesterase, and carboxylesterase and their activities were measured in adductor muscle and gills from oysters transplanted in Ebro Delta bays where the are traditionally grown. Enzyme activities were related with physico-chemical parameters and pesticide levels measured in water. Cholinesterase activities measured in gills were unaffected across sites and periods. Conversely, carboxylesterase activities in oyster gills varied across periods and sites and were negatively correlated with residue levels of organophoshporous and carbamate pesticides in water. Therefore, inhibition of carboxylesterase activities can be considered a good indicator of exposure to anti-cholinergic pesticides in oysters. PMID:23168234

Ochoa, Victoria; Riva, Carmen; Faria, Melissa; Barata, Carlos

2013-01-15

271

tert-Butyl N-benzyl-N-[4-(4-fluorobenzoylmethyl-2-pyridyl]carbamate  

Directory of Open Access Journals (Sweden)

Full Text Available In the crystal structure of the title compound, C25H25FN2O3, the pyridine ring makes dihedral angles of 75.1?(3, 39.4?(3 and 74.6?(3° with the phenyl ring, the carbamate plane and the 4-fluorophenyl ring, respectively. The phenyl ring makes dihedral angles of 77.2?(3 and 23.6?(3° with the carbamate plane and the 4-fluorophenyl ring, respectively. The 4-fluorophenyl ring is perpendicular to the carbamate plane, the dihedral angle between them being 89.5?(3°.

Pierre Koch

2008-11-01

272

The Geometry and Internal Rotational Barrier of Carbamic Acid and Several Derivatives  

OpenAIRE

The geometries of the following carbamate-containing molecules have been optimized at the ab initio SCF level using the MINI-1, 3-21G, and 6-31G* basis sets: carbamic acid, methylcarbamate, ethylcarbamate, N-methyl methylcarbamate, N,N-dimethyl methylcarbamate, N-vinyl methyl-carbamate and N-phenyl methylcarbamate. The latter two basis sets yield geometries in best agreement with experimental data. Calculated energy barriers for rotation about the C-N bond become progressively higher as the b...

Remko, M.; Scheiner, Steve

1988-01-01

273

Health Risk Associated with Pesticide Contamination of Fish from the Densu River Basin in Ghana  

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Full Text Available The Densu River Basin constitutes one of the largest agricultural areas in Ghana. The practice of using pesticides such as organochlorines, organophosphates, carbamates, pyrethroids and several others in agriculture and public health programs has raised concerns about potentially adverse effects on human health and the environment. In this study, a field survey was conducted to assess farmers’ knowledge of safe handling and use of pesticides. Residues of pesticides in fish samples as well as the potential health risk associated with exposure to these pesticides were also evaluated. Data obtained from the field survey indicate that a very high proportion of farmers are at high risk of pesticide poisoning from occupational exposure. More than 90% of farm workers do not practice safety precaution during pesticide formulation and application leading to considerable prevalence of pesticide related illness in this agricultural community. Pesticide residues in fish samples varied greatly; from 0.10 µgKg-1 to 30.90 µgKg-1, consumption of fish and fisheries product from the basin was no zero risk. The estimated dose for aldrin, methoxychlor, ?-chlordane, endrin aldehyde, endrin ketone, endrin, p'p'-DDT and ?- HCH do not pose a direct hazard to human health, although present in fish samples since the values were lower than toxic thresholds as well as reference dose. However, ?- HCH, heptachlor, ?-endosulfan, endosulfan Sulphate, p'p'-DDE and dieldrin levels exceeded the reference dose, indicating a great potential for systemic toxicity in children who are considered to be the most vulnerable population subgroup.

T. Adom

2011-03-01

274

Oxidative stress responses in blood and gills of Carassius auratus exposed to the mancozeb-containing carbamate fungicide Tattoo.  

Science.gov (United States)

Intensive use of pesticides, particularly dithiocarbamates, in agriculture often leads to contamination of freshwater ecosystems. To our knowledge, the mechanisms of toxicity to fish by the carbamate fungicide Tattoo that contains mancozeb [ethylenebis(dithiocarbamate)] have not been studied. The present study aimed to evaluate the effects of Tattoo on goldfish gills and blood, tissues that would have close early contact with the pollutant. Exposure of goldfish Carassius auratus to 3, 5 or 10mgL(-1) of Tattoo for 96h resulted in moderate lymphopenia (by 8 percent) with a concomitant increase in both stab (by 66-88 percent) and segmented (by 166 percent) neutrophils. An increase in the content of protein carbonyl groups in blood (by 137-184 percent) together with decreased levels of protein thiols (by 23 percent) and an enhancement of lipid peroxide concentrations (by 29 percent) in gills after exposure to 10mgL(-1) of Tattoo demonstrated the induction of mild oxidative stress in response to Tattoo exposure. At the same time, the activities of selected antioxidant enzymes were enhanced in gills: superoxide dismutase by 18-25 percent and catalase by 27 percent. A 34 percent increment in low molecular mass thiol concentrations (mainly represented by glutathione) also occurred in gills and could be related to increased activity (by 13-30 percent) of glucose-6-phosphate dehydrogenase. The results indicate that Tattoo exposure perturbs free radical processes, i.e. induces mild oxidative stress and enhances the activity of certain antioxidant and associated enzymes in goldfish gills. It is clear that goldfish respond to the presence of waterborne pesticide by adjusting antioxidant defenses through upregulation of activities of antioxidant and associated enzymes. PMID:22963715

Kubrak, Olga I; Atamaniuk, Tetiana M; Husak, Viktor V; Drohomyretska, Ivanna Z; Storey, Janet M; Storey, Kenneth B; Lushchak, Volodymyr I

2012-11-01

275

Pesticide management and their residues in sediments and surface and drinking water in the Mekong Delta, Vietnam.  

Science.gov (United States)

Public concern in Vietnam is increasing with respect to pesticide pollution of the environment and of drinking water resources. While established monitoring programs in the Mekong Delta (MD) focus on the analysis of organochlorines and some organophosphates, the environmental concentrations of more recently used pesticides such as carbamates, pyrethroides, and triazoles are not monitored. In the present study, household level pesticide use and management was therefore surveyed and combined with a one year environmental monitoring program of thirteen relevant pesticides (buprofezin, butachlor, cypermethrin, ?-endosulfan, ?-endosulfan, endosulfan-sulfate, fenobucarb, fipronil, isoprothiolane, pretilachlor, profenofos, propanil, and propiconazole) in surface water, soil, and sediment samples. The surveys showed that household level pesticide management remains suboptimal in the Mekong Delta. As a consequence, a wide range of pesticide residues were present in water, soil, and sediments throughout the monitoring period. Maximum concentrations recorded were up to 11.24 ?g l(-1) in water for isoprothiolane and up to 521 ?g kg(-1) dm in sediment for buprofezin. Annual average concentrations ranged up to 3.34 ?g l(-1) in water and up to 135 ?g kg(-1) dm in sediment, both for isoprothiolane. Occurrence of pesticides in the environment throughout the year and co-occurrence of several pesticides in the samples indicate a considerable chronic exposure of biota and humans to pesticides. This has a high relevance in the delta as water for drinking is often extracted from canals and rivers by rural households (GSO, 2005, and own surveys). The treatment used by the households for preparing surface water prior to consumption (flocculation followed by boiling) is insufficient for the removal of the studied pesticides and boiling can actually increase the concentration of non-volatile pollutants. PMID:23500396

Toan, Pham Van; Sebesvari, Zita; Bläsing, Melanie; Rosendahl, Ingrid; Renaud, Fabrice G

2013-05-01

276

Anti-androgenic activities of environmental pesticides in the MDA-kb2 reporter cell line.  

Science.gov (United States)

Pesticides have been suspected to act as endocrine disruptive compounds (EDCs) through several mechanisms of action, however data are still needed for a number of currently used pesticides. In the present study, 30 environmental pesticides selected from different chemical classes (azole, carbamate, dicarboximide, organochlorine, organophosphorus, oxadiazole, phenylureas, pyrazole, pyrimidine, pyrethroid and sulfonylureas) were tested for their ability to alter in vitro the transcriptional activity of the androgen receptor in the MDA-kb2 reporter cell line. The responsiveness of the system was checked by using a panel of reference ligands of androgen and glucocorticoid receptors. When tested alone at concentrations up to 10 ?M, none of the studied pesticides were able to induce the reporter gene after a 18 h exposure. Conversely, co-exposure experiments with 0.1 nM dihydrotestosterone (DHT) allowed identifying 15 active pesticides with IC(50) ranging from 0.2 ?M for vinclozolin to 12 ?M for fenarimol. Fipronil and bupirimate were here newly described for their AR antagonistic activity. PMID:20736058

Aït-Aïssa, S; Laskowski, S; Laville, N; Porcher, J-M; Brion, F

2010-10-01

277

Agricultural pesticide residues  

International Nuclear Information System (INIS)

The utilization of tracer techniques in the study of agricultural pesticide residues is reviewed under the following headings: lysimeter experiments, micro-ecosystems, translocation in soil, degradation of pesticides in soil, biological availability of soil-applied substances, bound residues in the soil, use of macro- and microautography, double and triple labelling, use of tracer labelling in animal experiments. (U.K.)

278

Application of Multi-Analyte Methods for Pesticide Formulations  

International Nuclear Information System (INIS)

The application of multi-analyte methods for pesticide formulations by GC analysis is discussed. HPLC was used to determine active ingredients. HPLC elution sequences were related to individual n-octanol/water partition coefficients. Real laboratory data are presented and evaluated with regard to validation requirements. The retention time data of pesticides on different HPLC columns under gradient and isocratic conditions are compared to illustrate the applicability of the methodologies. (author)

279

Toxicity of Organophosphate and Carbamate Insecticide Against Aedes aegypti Mosquitoes  

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Full Text Available Aedes aegypti mosquito is increasing problem of public health, being the vector responsible for Dengue and Chikungunya. Chlorpirifos (Organofosfat and Metonil (Carbamate were known to posses insecticide activity against insect. The study was aimed to examine effectiveness of Chlorpirifos and Metonil as insectiside against Ae. aegypti mos-quito Chlorpirifos a significantly higher insecticide activity against Ae. aegypti than Metonil. The mosquito mortality was observed after 24 h exposure. The LC50 value of Chlorpirifos and Metonil were 0.64 mg/lt and 0,802 mg/lt, against Ae. aegypti mosquito. The mixed of both insecticide was LC50 value 108.04 mg/lt, this result prove that mixed of both insecticede not sinergism. The result of this study suggested that Chlorpirifos more effective insecticide against Ae.aegypti than Metonil.

Endang Puji Astuti

2010-12-01

280

Brazilian vodkas have undetectable levels of ethyl carbamate  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english While in Europe vodka is mainly derived from potatoes or cereals, a large proportion of Brazilian vodka is likely obtained from sugarcane, which contains ethyl carbamate (EC) precursors. EC, in addition to several other contaminants and congeners, were investigated in 32 samples of Brazilian vodka. [...] All samples complied with the Brazilian regulations for congeners and contaminants, having EC content below 0.01 mg/L (detection limit). These results are probably related to the processing of vodka, in particular the use of extractive and rectifying stainless steel distillation columns, which allow the production of high strength spirits with low levels of congeners and contaminants.

Elainy V. S., Pereira; Sonia P. A., Oliveira; Ian C. C., Nóbrega; Dirk W., Lachenmeier; Adelia C. P., Araújo; Danuza L., Telles; Marileide, Silva.

281

Search for methyl carbamate in W51e2  

Science.gov (United States)

Complex organic molecules containing up to 10 atoms have been detected in several hot molecular clouds such as Orion or SgrB2. Glycine (NH2CH2COOH), the simplest amino acid, has been extensively searched in hot cores and in molecular outflows but has not been firmly detected yet. Using the 30m IRAM antenna at Pico Veleta, we have searched for the methyl carbamate (NH2COOCH3), the isomere of glycine, in the hot molecular cloud W51e2 and in the intermediate mass protostar IRAS21391+58502. This molecule, if present in molecular clouds, should be more favorable to detect than glycine thanks to its strong dipole moment. This poster presents the results from these observations.

Demyk, Karine; Wlodarczak, Georges; Dartois, Emmanuel

2004-12-01

282

In vitro inhibition of acetylcholinesterase from four marine species by organophosphates and carbamates  

Energy Technology Data Exchange (ETDEWEB)

The literature on the biological, physical, and pharmaceutical chemistry of cholinesterase is considerable and includes data on activators and inhibitors. Most of the work on specific anticholinesterasic agents has been concerned with carbamates and organophosphates. Because of the sensitivity of acetylcholinesterase to carbamates and organophosphates, the enzyme has been used as a biochemical indicator of pollution by these agents. However, the chemical reactivity of such chemicals has not been correlated with their effect on Ache and it is impossible to accurately predict biological effects based only on structure. The objectives of this study were to investigate the sensitivity of various marine animals to both organo-phosphates and carbamates. The study was conducted by assessing the in vitro effect of five organophosphates and three carbamates on acetylcholinesterase activity from the muscle of the shrimp Palaemon serratus, the fishes Scomber and Pleuronectes platessa, and from the whole mussels Mytilus edulis. All these species could be used for the monitoring of effect of pollutants.

Galgani, F.; Bocquene, G. (Institut Francais de Recherche pour l' Exploitation, Nantes (France))

1990-08-01

283

The thermal desorption of CO2 from amine carbamate solutions for the 13C isotope enrichment  

Science.gov (United States)

The CO2 desorption from amine carbamate in non-aqueous solvents is of major importance for isotopic enrichment of 13C. A series of experiments were carried out in order to set up the conditions for the CO2 desorption. For this purpose, a laboratory- scale plant for 13C isotope separation by chemical exchange between CO2 and amine carbamate was designed and used. The decomposition of the carbamate solution was mostly produced in the desorber and completed in the boiler. Two different-length desorbers were used, at different temperatures and liquid flow rates of the amine-non-aqueous solvent solutions. The residual CO2 was determined by using volumetric and gaschromatographic methods. These results can be used for enrichment of 13C by chemical exchange between CO2 and amine carbamate in nonaqueous solvents.

Dronca, S.; Varodi, C.; Gligan, M.; Stoia, V.; Baldea, A.; Hodor, I.

2012-02-01

284

Conformation analysis and computation of energy barrier to rotation about Csbnd N bond in para-methylphenyl carbamate and its solvent dependence in comparison with tertiary carbamates and tertiary amides  

Science.gov (United States)

Barrier to rotation about conjugated Csbnd N bond in p-Methyl phenyl carbamate (PMPC) was computed 14-16 kcal/mol at three levels of HF, B3LYP and MP2 using 6-311++G?? basis set. The solvent effect and energy barriers about Csbnd N bond in PMPC were compared to the case of tertiary carbamates and tertiary amides. Moreover, it is shown that in primary carbamates such as PMPC and tertiary amides isomerisation process passes through TS2 and TS1 respectively, while in tertiary carbamates goes through a combination of both TSs. Furthermore, X-ray analysis which is reported for the first time for primary aryl carbamates demonstrated that the inclusive plane of carbamate functional group is perpendicular to the plane of phenyl ring. The results of computations are completely in agreement with the X-ray data.

Modarresi-Alam, Ali Reza; Nowroozi, Alireza; Najafi, Parisa; Movahedifar, Fahimeh; Hajiabadi, Hossein

2014-11-01

285

Comparative Evaluation of Carbamates as Prophylactic Agents against Organophosphate Intoxication Rats  

Directory of Open Access Journals (Sweden)

Full Text Available Investigates the effects of two well-known carbamates, physostigmine and pyridostigmine against organophosphorous compound and nerve gas toxicity. Physostigmine pretreatment for 30 min enhanced the survival time of rats against DFP intoxication whereas it did not have any effect with sarin poisoning. However, pyridostigmine pretreatment did not produce any significant effect on survival time either against DFP or sarin intoxication. Treatment with atropine along with carbamates further enhanced significantly the survival time against DFP poisoning.

A. K. Chatterjee

2013-04-01

286

Palladium(ii)-catalyzed meta-selective direct arylation of O-?-naphthyl carbamate.  

Science.gov (United States)

Selective meta-arylation of O-?-naphthyl carbamate has been accomplished using Pd(OAc)2 as a catalyst precursor and K2S2O8 with AgOAc as the oxidant. A range of aryl boronic acids could be introduced in moderate to good yields. Mechanistic investigation shows that the carbamate substituent has a unique effect and the reaction undergoes an ortho-carbometallation/meta-direct arylation process. PMID:25478680

Zhang, Jingchang; Liu, Qingwen; Liu, Xufei; Zhang, Suoqin; Jiang, Pingping; Wang, Yanxiang; Luo, Shengyuan; Li, Yang; Wang, Qifeng

2014-12-01

287

Uncharged stereoregular nucleic acid analogs: 2. Morpholino nucleoside oligomers with carbamate internucleoside linkages.  

OpenAIRE

A novel oligonucleotide analog has been prepared from ribonucleoside derived morpholine subunits linked by carbamate groups. Oxidative cleavage of the 2',3' vicinal diol of cytidine followed by reductive amination of the resulting dialdehyde afforded the morpholine subunit. Coupling of the subunits are through carbamate moieties and the oligomers were characterized by 1H NMR and FAB MS. Evidence for interaction of the hexamer 19 with p(dG6) was found, but an atypical interaction of 19 with a ...

Stirchak, E. P.; Summerton, J. E.; Weller, D. D.

1989-01-01

288

Cumulative risk assessment of the exposure to organophosphorus and carbamate insecticides in the dutch diet  

OpenAIRE

We report the acute cumulative exposure to organophosphorus insecticides (OPs) and carbamates in the Dutch population and young children (1-6 years) via the diet. Residue data were derived from Dutch monitoring programmes performed during 2003-2005, and food consumption levels from the Dutch National Food Consumption Survey 1997/1998. The relative potency factor (RPF) approach was used to cumulate the exposure to OPs and carbamates using acephate and oxamyl as index compound respectively. The...

Boon, P. E.; Voet, H.; Raaij, M. T. M.; Klaveren, J. D.

2008-01-01

289

Watershed scale influence of pesticide reduction practices on pesticides and fishes within channelized agricultural headwater streams  

Science.gov (United States)

Implementation of pesticide reduction practices to reduce pesticide usage within agricultural watersheds has the potential to reduce pesticide concentrations within agricultural streams. The watershed scale influence of pesticide reduction practices on pesticides and the biota within agricultural he...

290

Health effects of pesticides  

OpenAIRE

Tea industry is one of the most important agro-industry of the country. Wide scale use of pesticides in tea cultivation to protect the crops from insect and fungus has led to buildup of their residues in several parts of tea plant, and around the area. Some of the pesticides are toxic and injurious to health and affect the environment. In India, a large member of pesticides have been registered for use in tea cultivation. But only few are being used currently and for which maximum residue lev...

Seth, P. K.

2003-01-01

291

Carbamate Toxicity and Protective effect of vit. A and vit. E on some biochemicalaspects of male albino rats  

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Full Text Available The effect of daily oral administration of carbamate (1/10 L.D50 on rats for 30 successive days were studied. The male rats were divided into five groups (control, control + oil, carbamate, carbamate + vit. A and carbamate + vit. E. Each group (except control and control + oil was daily administrated carbamate (0.012 mg/kg B.wt.. Two groups of carbamate ­ intoxicated animals provided with vit. A (700 mg/kg.B.wt or vit. E (10 mg/kg.B.wt. Poisoning symptoms were recorded, e.g. unbalanse, diarrhea, have poor health and posterior limbs rigidity. Haematological parameters showed a significant decrease in red blood corpuscles (R.B.Cs, white blood corpuscles (W.B.Cs count, Haemoglobin concentration and haematocrit value in groups treated with carbamate, and an improvement in these values was observed in groups treated with the anti-oxidants (vit. A and vit. E. Total lipids cholesterol, total proteins, albumin, glucose, LDH, AST, ALT, adrenaline and noradrenaline were measured in serum. Total proteins, total lipids, of tissues (liver, heart, muscle and kidney were investigated. The present study declare that, carbamate induced a significant elevetion in serum LDH, glucose. total lipids,cholesterol, AST, ALT, adrenaline and noradrenaline. On the other hand, causes a significant reduction in total proteins and albumin. The total lipids and total proteins of the tissue were recorded highly significant decrease in the group treated with carbamate only. From another point of view, antioxidant ameliorated the effect of carbamate on tissues. So, it is clear that administration of vit. E or vit. A. reduced the effect of carbamate on biochemical alteration to various extent. The antioxidant property of vitamin A and vitamin E seem to be responsible for the observed protection against carbamate intoxication.

Samir, A.M. Zaahkouk* ; Eman, G.E. Helal

2000-12-01

292

Health Risk Assessment of Pesticide Usage in Menia El-Kamh Province of Sharkia Governorate in Egypt  

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Full Text Available Abstract: Menia El-Kamh province of the Sharkia Governorate constitutes one of the largest agricultural areas in Egypt. About 88% of the nearly 472,000 people living in this province rely on agricultural activities for subsistence. Several pesticides including organochloride, organophosphorus, carbamate, and pyrethroid insecticides, fungicides, and herbicides are commonly used in citrus, vegetable and other crop-growing areas to increase agricultural productivity. However, their use has also been associated with several cases of pesticide poisoning. In this research, we conducted a field survey to assess the knowledge, attitudes, and practices of the farmer’s community regarding the safe use of pesticides. We also evaluated the residual concentrations of selected pesticides in water, soil, milk, fish, and orange samples, and estimated the potential health risks associated with the exposure to these pesticides. Data obtained from the field survey indicate that more than 95% of farm workers do not practice safety precautions during pesticide formulation and application; leading to a considerable prevalence of pesticide-related illnesses in this agricultural community. Pesticide residues in various environmental samples varied greatly; from below detection levels (3-5 ng to as high as 325 ppb depending on the matrix of interest, and the specific pesticide of concern. The analysis of health risk estimates indicated that chlorpyrifos, DDT, dimethoate, methomyl, and larvin did not pose a direct hazard to human health, although present in water, milk, orange, and/or fish. However, aldicarb, and carbosulfan levels exceeded the reference doses, indicating a great potential for systemic toxicity, especially in children who are considered to be the most vulnerable population subgroup. The upper-bound values of cancer risk from DDT exposure were estimated to be about 8 (adults, and 55 (children excess cancers in a population of one million.

Jean-Claude Assad

2002-10-01

293

Optimización de un método para la detección de carbamatos y organofosforados en vegetales Optimization of a method for the detection of organophosphates and carbamates in vegetables  

Directory of Open Access Journals (Sweden)

Full Text Available Debido al alto grado de contaminación por plaguicidas de productos agrícolas y al alto costo que implica su detección se consideró importante optimizar el método de escrutinio de inhibición de colinesterasas humanas en presencia de extractos vegetales. Se demostró que las suspensiones de glóbulos rojos y plasma son estables al menos por tres meses si se mantienen entre 4 y 8 °C. El reactivo de color es estable por al menos dos años y medio en refrigeración y los sustratos de ambas colinesterasas son estables congelados al menos por dos años. La mezcla del extracto vegetal y los glóbulos rojos o plasma debe incubarse 90 minutos a 37 °C para determinar los porcentajes de inhibición enzimática. Se determinó que los porcentajes de inhibición superiores a 16% en la plasmática y a 21% en la eritrocítica indican presencia de plaguicida en los vegetales. Este método de screening optimizado para detectar la presencia de carbamatos y organofosforados tiene ventaja sobre otros por su bajo costo, facilidad y rapidez de análisis sin requerir de equipo costoso y poco versátil. Esta metodología no cuantifica ni identifica el plaguicida presente pero permite diferenciar entre organofosforados y carbamatos si el periodo de incubación del vegetal con eritrocitos o plasma se prolonga por 24 horas a 20-25 °C.Optimization of the screening method of inhibition of human cholinesterases is considered important because of the high contamination rate of agricultural products with pesticides and its high detection cost. It has been demonstrated that erythrocytes and plasma are stable at least for three months at 4-8 °C. The colour reaction reagent is stable for at least two and a half years at 4-8 °C and the substrate for both cholinesterases is stable when frozen, at least for two years. The solution of vegetable extract and erythrocytes or plasma must be incubated 90 minutes at 37 °C in order to determine the percentages of enzymatic inhibition. It was established that inhibition percentages higher than 16% for the plasmatic solution, and 21% for the erythrocytic solution mean that pesticide is present in vegetables. The advantages of this optimized screening method for the detection of carbamates and organophosphates in vegetables are its low cost and its easy and quick analysis without the need of expensive equipment. This method does not quantify or identify the pesticide, but rather it differentiates organophosphates from carbamates if the incubation time of the vegetable extract with erythrocytes or plasma is maintained at 20- 25 °C for 24 hours.

Karl Schosinsky

2009-03-01

294

Optimización de un método para la detección de carbamatos y organofosforados en vegetales / Optimization of a method for the detection of organophosphates and carbamates in vegetables  

Scientific Electronic Library Online (English)

Full Text Available SciELO Argentina | Language: Spanish Abstract in spanish Debido al alto grado de contaminación por plaguicidas de productos agrícolas y al alto costo que implica su detección se consideró importante optimizar el método de escrutinio de inhibición de colinesterasas humanas en presencia de extractos vegetales. Se demostró que las suspensiones de glóbulos ro [...] jos y plasma son estables al menos por tres meses si se mantienen entre 4 y 8 °C. El reactivo de color es estable por al menos dos años y medio en refrigeración y los sustratos de ambas colinesterasas son estables congelados al menos por dos años. La mezcla del extracto vegetal y los glóbulos rojos o plasma debe incubarse 90 minutos a 37 °C para determinar los porcentajes de inhibición enzimática. Se determinó que los porcentajes de inhibición superiores a 16% en la plasmática y a 21% en la eritrocítica indican presencia de plaguicida en los vegetales. Este método de screening optimizado para detectar la presencia de carbamatos y organofosforados tiene ventaja sobre otros por su bajo costo, facilidad y rapidez de análisis sin requerir de equipo costoso y poco versátil. Esta metodología no cuantifica ni identifica el plaguicida presente pero permite diferenciar entre organofosforados y carbamatos si el periodo de incubación del vegetal con eritrocitos o plasma se prolonga por 24 horas a 20-25 °C. Abstract in english Optimization of the screening method of inhibition of human cholinesterases is considered important because of the high contamination rate of agricultural products with pesticides and its high detection cost. It has been demonstrated that erythrocytes and plasma are stable at least for three months [...] at 4-8 °C. The colour reaction reagent is stable for at least two and a half years at 4-8 °C and the substrate for both cholinesterases is stable when frozen, at least for two years. The solution of vegetable extract and erythrocytes or plasma must be incubated 90 minutes at 37 °C in order to determine the percentages of enzymatic inhibition. It was established that inhibition percentages higher than 16% for the plasmatic solution, and 21% for the erythrocytic solution mean that pesticide is present in vegetables. The advantages of this optimized screening method for the detection of carbamates and organophosphates in vegetables are its low cost and its easy and quick analysis without the need of expensive equipment. This method does not quantify or identify the pesticide, but rather it differentiates organophosphates from carbamates if the incubation time of the vegetable extract with erythrocytes or plasma is maintained at 20- 25 °C for 24 hours.

Karl, Schosinsky; Eugenia María, Quintana Guzmán; Clements, Ruepert.

2009-03-01

295

Inhibition of plasma butyrylcholinesterase activity in the lizard Gallotia galloti palmae by pesticides: a field study  

International Nuclear Information System (INIS)

A field study was performed to evaluate the effect of exposure to organophosphorus (OP) and carbamate (CB) pesticides on the lizard Gallotia galloti palmae. Butyrylcholinesterase (BChE) activity was measured in the plasma of 420 lizards collected from agricultural and reference areas on the Island of La Palma (Canary Islands, Spain) in two sampling periods. Exposure to cholinesterase-inhibiting pesticides was evaluated by a statistical criterion based on a threshold value (two standard deviations below the mean enzyme activity) calculated for the reference group, and a chemical criterion based on the in vitro reactivation of BChE activity using pyridine-2-aldoxime methochloride (2-PAM) or after water dilution of the sample. Mean (±SD) BChE activity for lizards from agricultural areas was significantly lower (Fuencaliente site = 2.00 ± 0.98 ?mol min-1 ml-1, Tazacorte site = 2.88 ± 1.08) than that for lizards from the reference areas (Los Llanos site = 3.06 ± 1.17 ?mol min-1 ml-1, Tigalate site = 3.96 ± 1.62). According to the statistical criterion, the number of lizards with BChE depressed was higher at Fuencaliente (22% of males and 25.4% of females) than that sampled at Tazacorte (7.8% of males and 6.2% of females). According to the chemical criterion, Fuencaliente also yielded a higher number of individuals (112 males and 47 females) with BChE activity inhibited by both OP and CB pesticides. CBs appeared to be the pesticides. CBs appeared to be the pesticides most responsible for BChE inhibition because most of the samples showed reactivation of BChE activity after water treatment (63.3% from Fuencaliente and 29% from Tazacorte). We concluded that the use of reactivation techniques on plasma BChE activity is a better and more accurate method for assessing field exposure to OP/CB pesticides in this lizard species than making direct comparisons of enzyme activity levels between sampling areas. - Capsule: Chemical reactivation of lizard BChE activity is a suitable diagnostic method for evaluating field exposure to organophosphorus and carbamate pesticides

296

What Is a Pesticide?  

Science.gov (United States)

... insects, mice and other animals, unwanted plants (weeds), fungi, microorganisms such as bacteria and viruses, and prions . (578 kb, 8 pgs, PDF) Do household products contain pesticides? Many household products ...

297

Pesticide-Exposure Matrix  

Science.gov (United States)

The "Pesticide-exposure Matrix" was developed to help epidemiologists and other researchers identify the active ingredients to which people were likely exposed when their homes and gardens were treated for pests in past years.

298

SPEAR indicates pesticide effects in streams - Comparative use of species- and family-level biomonitoring data  

Energy Technology Data Exchange (ETDEWEB)

To detect effects of pesticides on non-target freshwater organisms the Species at risk (SPEAR{sub pesticides}) bioindicator based on biological traits was previously developed and successfully validated over different biogeographical regions of Europe using species-level data on stream invertebrates. Since many freshwater biomonitoring programmes have family-level taxonomic resolution we tested the applicability of SPEAR{sub pesticides} with family-level biomonitoring data to indicate pesticide effects in streams (i.e. insecticide toxicity of pesticides). The study showed that the explanatory power of the family-level SPEAR(fm){sub pesticides} is not significantly lower than the species-level index. The results suggest that the family-level SPEAR(fm){sub pesticides} is a sensitive, cost-effective, and potentially European-wide bioindicator of pesticide contamination in flowing waters. Class boundaries for SPEAR{sub pesticides} according to EU Water Framework Directive are defined to contribute to the assessment of ecological status of water bodies. - We show that SPEAR{sub pesticides} can be based on family-level biomonitoring data and is applicable for large-scale monitoring programmes to detect and quantify pesticide contamination.

Beketov, M.A., E-mail: mikhail.beketov@ufz.d [UFZ - Helmholtz Centre for Environmental Research, Department System Ecotoxicology, Permoserstrasse 15, D-04318 Leipzig (Germany); Foit, K.; Schaefer, R.B.; Schriever, C.A. [UFZ - Helmholtz Centre for Environmental Research, Department System Ecotoxicology, Permoserstrasse 15, D-04318 Leipzig (Germany); Sacchi, A.; Capri, E. [Universita Cattolica del Sacro Cuore, Istituto di Chimica Agraria ed Ambientale, Piacenza (Italy); Biggs, J. [Pond Conservation, c/o Oxford Brookes University, Headington (United Kingdom); Wells, C. [Environment Agency of England and Wales, Science Department, Bristol (United Kingdom); Liess, M. [UFZ - Helmholtz Centre for Environmental Research, Department System Ecotoxicology, Permoserstrasse 15, D-04318 Leipzig (Germany)

2009-06-15

299

Genotoxicity of chlororganic pesticides  

International Nuclear Information System (INIS)

In Kazakhstan there are the warehouses of the obsolete pesticides and their container which should be buried in special burial grounds or neutralized to minimize dangerous genetic and ecological risks. The results of two yr of research were identification of substances stored in 64 former warehouses of pesticides. 64 former warehouses (in the 10 areas of Almaty oblast) are on distance of 250 km from a large city of Almaty (the former capital of Kazakhstan). A total of 352,6 ton of obsolete pesticides and 250 ton of their container were disposed. We determined the residues of DDT metabolites (dichlorodiphenyltrichloroethane) and HCH isomers (hexachlorocyclohexane) in soil around pesticides warehouses where their concentrations exceed MAC (maximum concentration limit) in tens - hundreds times. To analyze a genotoxicity of chlororganic pesticides we used their concentrations that were found in soil from former warehouses. The analysis of structural mutations of chromosomes was carried out by metaphase method in I mitoses meristem cells of barley seeds (Hordeum vulgare L.). It was ascertained that HCH isomers and DDT metabolites have genotoxic effect exceeding spontaneous mutation in 5-7 times. High contaminations by pesticides on soil around of warehouses and their ability to induce chromosome aberrations in plant cells indicate that warehouses are a new centre of contamination by POP's (proof organic pollutants). (author)

300

Pesticide transport simulation in a tropical catchment by SWAT.  

Science.gov (United States)

The application of agrochemicals in Southeast Asia is increasing in rate, variety and toxicity with alarming speed. Understanding the behavior of these different contaminants within the environment require comprehensive monitoring programs as well as accurate simulations with hydrological models. We used the SWAT hydrological model to simulate the fate of three different pesticides, one of each usage type (herbicide, fungicide and insecticide) in a mountainous catchment in Northern Thailand. Three key parameters were identified: the sorption coefficient, the decay coefficient and the coefficient controlling pesticide percolation. We yielded satisfactory results simulating pesticide load dynamics during the calibration period (NSE: 0.92-0.67); the results during the validation period were also acceptable (NSE: 0.61-0.28). The results of this study are an important step in understanding the modeling behavior of these pesticides in SWAT and will help to identify thresholds of worst-case scenarios in order to assess the risk for the environment. PMID:24811948

Bannwarth, M A; Sangchan, W; Hugenschmidt, C; Lamers, M; Ingwersen, J; Ziegler, A D; Streck, T

2014-08-01

301

Health risks of employees working in pesticide retail shops: An exploratory study  

Directory of Open Access Journals (Sweden)

Full Text Available Background: Shop keepers dealing with pesticides are exposed to multiple pesticides that include organophosphates, organochlorines, carbamates, pyrethroids. Hence an exploratory health study was conducted on shopkeepers selling pesticides in urban areas of Lucknow and Barabanki District, Uttar Pradesh, India. Materials and Methods: Detailed information regarding socio-economic status, family history, personal habits and work practices were recorded for 20 subjects and controls by the investigator on a pre-tested questionnaire. Clinical examination including neurological studies of the shopkeepers and control subjects was done. Results: The study revealed significant slowing of motor nerve conduction velocity and low peak expiratory flow rate among shopkeepers as compared to control subjects. Prevalence of significantly higher gastro-intestinal problems was also observed among exposed subjects. Neurological, ocular, cardiovascular and musculo-skeletal symptoms were also found to be higher among shopkeepers. This was not statistically significant. Significantly higher relative risk for sickness related to systems viz., cardio-vasular, genito-urinary, respiratory, nervous and dermal was observed among exposed subjects compared to controls. Conclusions: These findings provide a prima facie evidence of clinical manifestations because of multiple exposures to pesticides and poor safety culture at work place.

Kesavachandran C

2009-01-01

302

Acute oral and percutaneous toxicity of pesticides to mallards: Correlations with mammalian toxicity data  

Science.gov (United States)

Acute oral (po) and 24-hr percutaneous (perc) LD50 values for 21 common pesticides (19 anticholinesterases, of which 18 were organophosphates, and one was a carbamate; one was an organochlorine central nervous system stimulant; and one was an organonitrogen pneumotoxicant) were determined in mallards (Anas platyrhynchos). Three of the pesticides tested were more toxic percutaneously than orally. An index to the percutaneous hazard of a pesticide, the dermal toxicity index (DTI = po LD50/perc LD50 ? 100), was also calculated for each pesticide. These toxicity values in mallards were compared with toxicity data for rats from the literature. Significant positive correlations were found between log po and log percutaneous LD50 values in mallards (r = 0.65, p 0.10). Variations in percutaneous methodologies are discussed with reference to interspecies variation in toxicity values. It is recommended that a mammalian DTI value approaching 30 be used as a guideline for the initiation of percutaneous toxicity studies in birds, when the po LD50 and/or projected percutaneous LD50 are less than expected field exposure levels.

Hudson, R.H.; Haegele, M.A.; Tucker, R.K.

1979-01-01

303

Disposable biosensor test for organophosphate and carbamate insecticides in milk.  

Science.gov (United States)

A highly sensitive and rapid biosensor test based on disposable screen-printed thick-film electrodes was developed, which is suitable for monitoring organophosphate and carbamate residues in foods of animal origin with increased fat contents such as milk. The wild-type enzyme was combined with three engineered variants of Nippostrongylus brasiliensis acetylcholinesterase (NbAChE), to obtain enhanced sensitivity. The sample pretreatment could be reduced to a minimum. There was no extraction or fat removal necessary. With the biosensor test paraoxon concentrations down to 1 microg/L could be detected in milk. The detection limit for carbaryl was 20 microg/L. Recovery rates for paraoxon and carbaryl in milk samples lay between 89 and 107%. Ten milk samples from local markets were tested both with the biosensor test and with standard chromatographic multiresidue methods. Two milk samples caused AChE inhibition rates of >50%. Accordingly, 4 microg/L tebufenpyrad, 4 microg/L tetraconazole, and 2 microg/L bifenthrin were detected in one of these milk samples. The other milk sample contained 2 microg/L tebufenpyrad. PMID:15969483

Zhang, Yaodong; Muench, Susanne B; Schulze, Holger; Perz, Roland; Yang, Bolun; Schmid, Rolf D; Bachmann, Till T

2005-06-29

304

Pesticide Movement in Response to Furrow Irrigation and Pesticide Parameters  

OpenAIRE

Production of adequate supplies of food and fiber currently requires that pesticides be used to limit crop losses from insects, pathogens, weeds and other pests. The term pesticide refers to a large number ofchemical compounds. Pesticides include acaricides, fungicides, herbicides, insecticides, nematicides, algicides, arboricides, zoocides, and many more.

Ranjha, A. Y.; Peralta, R. C.; Hill, R. W.; Deer, H. M.

1991-01-01

305

The enthalpies of formation of alkyl carbamates: Experimental and computational redetermination  

International Nuclear Information System (INIS)

Highlights: ? Combustion calorimetry was used to redetermine ?fHmo(cr) of methyl and ethyl carbamates. ? ?crgHmo of methyl and ethyl carbamates were redetermined by Calvet Microcalorimetry. ? Gas-phase ?fHmo of the studied compounds have been derived from the experimental values of ?fHmo (cr) and ?crgHmo. ? Gas-phase ?fHmo of the studied compounds have been calculated by computational thermochemistry. ? The obtained ?fHmo(g) for the alkylcarbamates are discussed versus literature values for the same compounds. - Abstract: In the present work, a redetermination of thermochemical data of methyl carbamate and ethyl carbamate was performed by both experimental and computational techniques. Their gas-phase standard (po = 0.1 MPa) molar enthalpies of formation, ?fHmo(g), at T = 298.15 K, were derived from the standard molar enthalpies of formation, in the crystalline phase, ?fHmo(cr), and from the standard molar enthalpies of sublimation, ?crgHmo at T = 298.15 K, measured, respectively, by static bomb combustion calorimetry and high temperature Calvet microcalorimetry. The experimental rry. The experimental results were compared with computational data, calculated at the G3(MP2)//B3LYP level, as well as with values reported in the literature. At the B3LYP/6-31G(d) level of theory, the molecular structure of both carbamates was obtained.

306

Pesticide use in periurban areas  

OpenAIRE

Public concern about pesticide use is very high, although it varies with social, ethical and political factors. In periurban regions, farmers live close to people with other occupations. Thus farming activities such as pesticide spraying may cause tensions. Pesticide use may also cause changes in pest abundances outside the treated field, on plants in neighbouring gardens. The first part of this thesis compared perceptions of pesticide use by farmers and their neighbours in two periurban r...

Ahmed, Nur

2012-01-01

307

Assessment of Acute Oral and Dermal Toxicity of 2 Ethyl-Carbamates with Activity against Rhipicephalus microplus in Rats  

Science.gov (United States)

The acute oral and dermal toxicity of two new ethyl-carbamates (ethyl-4-bromophenyl-carbamate and ethyl-4-chlorophenyl-carbamate) with ixodicide activity was determined in rats. The oral LD50 of each carbamate was 300 to 2000?mg/kg, and the dermal LD50 of each carbamate was >5000?mg/kg. Clinically, the surviving rats that had received oral doses of each carbamate showed decreased weight gain (P < 0.05) and had slight nervous system manifestations. These clinical signs were evident from the 300?mg/kg dose and were reversible, whereas the 2000?mg/kg dose caused severe damage and either caused their death or was motive for euthanasia. At necropsy, these rats had dilated stomachs and cecums with diffuse congestion, as well as moderate congestion of the liver. Histologically, the liver showed slight degenerative lesions, binucleated hepatocytes, focal coagulative necrosis, and congestion areas; the severity of the lesions increased with dosage. Furthermore, an slight increase in gamma-glutamyltransferase, lactate dehydrogenase, and creatinine was observed in the plasma. The dermal application of the maximum dose (5000?mg/kg) of each carbamate did not cause clinical manifestations or liver and skin alterations. This finding demonstrates that the carbamates under study have a low oral hazard and low acute dermal toxicity. PMID:24883331

Prado-Ochoa, María Guadalupe; Gutiérrez-Amezquita, Ricardo Alfonso; Abrego-Reyes, Víctor Hugo; Velázquez-Sánchez, Ana María; Muñoz-Guzmán, Marco Antonio; Ramírez-Noguera, Patricia; Angeles, Enrique; Alba-Hurtado, Fernando

2014-01-01

308

New synthesis of carbamate, thiocarbamate and urea type herbicides: preparation of 14C-labelled diuron and EPTC  

International Nuclear Information System (INIS)

N,N-dialkyl-carbamic acid-trimethylsilyl-esters were synthesized starting with 14CO2. The new synthesis route is simple and provides good radiochemical yield. Silyl-carbaminates directly or through carbamoyl-halogenides may be used for preparation of labelled herbicides: carbamates, thiocarbamates and ureas. (author)

309

Carbamate-directed hydroboration: Enantioselective synthesis of the excitatory amino acid 1-aminocyclopentane-1,3-dicarboxylic acid  

OpenAIRE

Carbamate-directed hydroboration (using BH3) of 1-substituted 3- cyclopentenes 2, 6 and 9 and an enantioselective synthesis of the excitatory amine acid 1-aminocyclopentane-1,3-dicarboxylic acid via carbamate-directed asymmetric hydroboration [90% de, 45% ee using (+)-IpcBH2] of cyclopentene 2 are described.

Hodgson, Dm; Thompson, AJ; Wadman, S.

1998-01-01

310

Time-course, dose-response, and age comparative sensitivity of N-methyl carbamates in rats  

Science.gov (United States)

N-Methyl carbamate insecticides are reversible inhibitors of central and peripheral acetylcholinesterease (ChE). Despite their widespread use, there are few studies of neurotoxicity in young animals. To study potential age-related differences, we evaluated seven carbamates (carba...

311

Reagentless bidirectional lateral flow bioactive paper sensors for detection of pesticides in beverage and food samples.  

Science.gov (United States)

A reagentless bioactive paper-based solid-phase biosensor was developed for detection of acetylcholinesterase (AChE) inhibitors, including organophosphate pesticides. The assay strip is composed of a paper support (1 x 10 cm), onto which AChE and a chromogenic substrate, indophenyl acetate (IPA), were entrapped using biocompatible sol-gel derived silica inks in two different zones (e.g., sensing and substrate zones). The assay protocol involves first introducing the sample to the sensing zone via lateral flow of a pesticide-containing solution. Following an incubation period, the opposite end of the paper support is placed into distilled deionized water (ddH(2)O) to allow lateral flow in the opposite direction to move paper-bound IPA to the sensing area to initiate enzyme catalyzed hydrolysis of the substrate, causing a yellow-to-blue color change. The modified sensor is able to detect pesticides without the use of any external reagents with excellent detection limits (bendiocarb approximately 1 nM; carbaryl approximately 10 nM; paraoxon approximately 1 nM; malathion approximately 10 nM) and rapid response times (approximately 5 min). The sensor strip showed negligible matrix effects in detection of pesticides in spiked milk and apple juice samples. Bioactive paper-based assays on pesticide residues collected from food samples showed good agreement with a conventional mass spectrometric assay method. The bioactive paper assay should, therefore, be suitable for rapid screening of trace levels of organophosphate and carbamate pesticides in environmental and food samples. PMID:19788278

Hossain, S M Zakir; Luckham, Roger E; McFadden, Meghan J; Brennan, John D

2009-11-01

312

Effects of subacute pretreatment with carbamate together with acute adjunct pretreatment against nerve agent exposure. (Reannouncement with new availability information)  

Energy Technology Data Exchange (ETDEWEB)

Acute carbamate pretreatment, in conjunction with atropine pretreatment or followed by atropine and oxime therapy has been shown to protect rabbits, rats, guinea pigs and monkeys against multiple lethal doses of soman. In those experiments, pretreated animals were usually challenged with soman at the time of peak whole blood acetylcholinesterase (AChE) inhibition by the carbamate or when the concentration of carbamate in the blood was expected to be rapidly diminishing. However, soldiers in a chemical environment, having taken carbamate orally might well be exposed to nerve agent shortly thereafter. Thus, both active carbamate and nerve agent would be entering the blood simultaneously. In a recent study it was reported that subacute administration of physostigmine (Phy), via subcutaneously implanted 28 day osmotic minipump, afforded protection against an iv challenge of soman on the 27th day.

Anderson, D.R.; Harris, L.W.; Lennox, W.J.; Solana, R.P.

1991-12-31

313

Effect of new ethyl and methyl carbamates on Rhipicephalus microplus larvae and adult ticks resistant to conventional ixodicides.  

Science.gov (United States)

The effects of six new synthetic carbamates on fully engorged females of four Rhipicephalus microplus strains (one reference strain susceptible to conventional ixodicides, two strains multiresistant to ixodicides and one tick field isolate) were compared. In addition, the effect of two other new synthetic carbamates was tested on larvae from the same strains. The first six tested carbamates reduced egg laying and inhibited egg hatching in the four studied strains (Pcarbamates induced larval mortality in all of the evaluated strains. The three studied R. microplus strains displayed 50% resistance ratios (RR50) of less than 2 when compared to the susceptible reference strain. These results demonstrate that both carbamates with a larvicidal effect and carbamates that inhibit egg laying and embryo development are efficacious against tick strains that are resistant to commercial ixodicides, no cross resistance was observed. PMID:24315692

Pérez-González, I E; Prado-Ochoa, M G; Muñoz-Guzmán, M A; Vázquez-Valadez, V H; Velázquez-Sánchez, A M; Avila-Suárez, B L; Cuenca-Verde, C; Angeles, E; Alba-Hurtado, F

2014-01-31

314

Pesticide Action Network UK  

Science.gov (United States)

The Pesticide Action Network UK (PAN UK) is a nonprofit organization that "promotes healthy food, agriculture and an environment which will provide food and meet public health needs without dependence on toxic chemicals, and without harm to food producers and agricultural workers.ïÿý Through its website, PAN UK offers a number of downloadable publications including briefings; fact sheets for active ingredients like aldicarb, cypermethrin, methyl parathion, and paraquat; monthly gardening tips, and annual reviews. Site visitors can also search for pesticide-related images and numerous publication listings through the website's Photographic Database and Research Database. The site also contains pesticide-related news, press releases, and information about PAN UK activities in the United Kingdom, Europe, and around the world. Many related links are included as well in such categories as Conferences, Consumer Links, Databases & Resources, Integrated Pest Management, and more.

315

In Case of Pesticide Poisoning  

Science.gov (United States)

... Symptoms of Heat Exhaustion Symptoms of Organophosphate/ Carbamate Poisoning Sweating Sweating Headache Headache Fatigue Fatigue Dry membranes Moist membranes Dry mouth Salivation No tears Tears No spit present Spit present in mouth Fast pulse (slow if person has fainted) Slow pulse Nausea Nausea ...

316

Synthesis and anti-HIV activity of carbamates of antiviral agent stavudine.  

Science.gov (United States)

An efficient synthesis of carbamate analogues of the NRTI compound stavudine, has been achieved in five steps starting from commercially available thymidine. The synthesis involves conversion of thymidine into stavudine followed by condensation with carbaimidazole derivative obtained from various aromatic and heterocyclic amines in dimethylformamide solvent. The analogues thus obtained were further purified by crystallization to furnish analytically pure products. Examination of biological activity of these carbamate derivatives of stavudine showed that they inhibited HIV replication only at micro-molar concentrations. PMID:12630677

Venkatachalam, T K; Samuel, P; Kourinov, I V; Uckun, F M

2002-09-01

317

The carcinogenic potential of ethyl carbamate (urethane): risk assessment at human dietary exposure levels.  

Science.gov (United States)

Ethyl carbamate is found in fermented foods: bread contains 3-15 ng/g, stone-fruit brandies 200-20,000 ng/g, and about one-third of table-wine samples analysed contained more than 10 ng/g. In animals, ethyl carbamate is degraded to CO2, H2O and NH3, with intermediate formation of ethanol. This degradation has been shown to be inhibited (postponed) in the mouse by ethanol concentrations in the blood of about 0.15% and higher. A quantitatively minor pathway involves a two-step oxidation of the ethyl group to vinyl carbamate and epoxyethyl carbamate, the postulated electrophilic moiety that reacts with DNA. This reaction is probably the mode of the mutagenic action observed in many cellular and animal systems. The fact that only vinyl carbamate, but not ethyl carbamate, is mutagenic in a standard Ames test is probably because there is insufficient production of the intermediate oxidation product in the standard test. Consistent with this metabolism is the carcinogenic activity of ethyl carbamate in various animal species and in different organs; this activity can be seen even after a single high dose in early life. Quantitative analysis of the total tumour incidences after chronic exposure of rats and mice to 0.1-12.5 mg ethyl carbamate/kg body weight/day in the drinking-water showed a dose-related increase. The main target organs were the mammary gland (female rats and mice having similar susceptibilities) and the lung (mice only). On the basis of sex- and organ-specific tumour data and with a linear extrapolation to a negligible increase of the lifetime tumour incidence by 0.0001% (one additional tumour in one million individuals exposed for life), a "virtually safe dose" of 20 to 80 ng/kg body weight/day was estimated. The daily burden reached under normal dietary habits without alcoholic beverages is in the range of about 20 ng/kg body weight/day. Regular table-wine consumption would increase the risk by a factor of up to five. Regular drinking of 20 to 40 ml stone-fruit brandy per day could raise the calculated lifetime tumour risk to near 0.01%. PMID:2188890

Schlatter, J; Lutz, W K

1990-03-01

318

Carbolithiation of N-alkenyl ureas and N-alkenyl carbamates  

Directory of Open Access Journals (Sweden)

Full Text Available N-Alkenyl ureas and N-alkenyl carbamates, like other N-acyl enamines, are typically nucleophilic at their ?-carbon. However, by incorporating an ?-aryl substituent, we show that they will also undergo attack at the ?-carbon by organolithium nucleophiles, leading to the products of carbolithiation. The carbolithiation of E and Z N-alkenyl ureas is diastereospecific, and N-tert-butoxycarbonyl N-alkenyl carbamates give carbolithiation products that may be deprotected in situ to provide a new connective route to hindered amines.

Julien Lefranc

2013-03-01

319

2-(1-Methyl­ethoxy)-5-nitro­phenyl N-methyl­carbamate  

OpenAIRE

In the title compound, C11H14N2O5, the nitro group is approximately coplanar with the benzene ring, making a dihedral angle of 4.26?(17)°. The dihedral angle between the methyl­carbamate group and the benzene ring is 72.47?(6)°. There is a strong inter­molecular N—H?O hydrogen bond between the N and O atoms from adjacent methyl­carbamate groups, forming a one-dimensional network along the a axis.

Sang, Guang-ming; Luo, Shi-neng; Lin, Jian-guo; Yang, Hai-lin; Xia, Yong-mei

2008-01-01

320

Film formation of ?-aminoalkylcellulose carbamates - A quartz crystal microbalance (QCM) study.  

Science.gov (United States)

The film formation of novel ?-aminoalkylcellulose carbamates on gold surface was studied by means of quartz crystal microbalance with dissipation monitoring (QCM-D) and atomic force microscopy (AFM). The influence of the pH value of the buffer solution, the concentration, the degree of polymerization, and the structure (spacer length) of the polymers on the coating was investigated. The layer formation was explained based on the pKa value and the degree of substitution of the ?-aminoalkylcellulose carbamates determined by potentiometric titration. This work provides novel supporting materials that might be applied in field of immobilization of biomolecules. PMID:25458279

Elschner, Thomas; Doliška, Aleš; Bra?i?, Matej; Stana-Kleinschek, Karin; Heinze, Thomas

2015-02-13

321

Enrichment of 13C by chemical exchange between CO2 and amine carbamate in nonaqueous solvents  

International Nuclear Information System (INIS)

Enrichment of 13C by chemical exchange between CO2 and amine carbamate in nonaqueous solvents has been mathematically modelled in two ways. The height equivalent to a theoretical plate and steady-state separation, based on the two models, have been obtained. If only the isotopic exchange between CO2 gas and amine carbamate is considered, the model can estimate the process performance for pressures close to the atmospheric one and room temperature. For process analysis at pressures higher than the atmospheric one and lower temperatures, a two-step model has been used. Using the two models the effects of pressure have been studied. (author)

322

Enrichment of 13 C by chemical exchange between CO2 and amine carbamate in nonaqueous solvents  

International Nuclear Information System (INIS)

Enrichment of 13 C by chemical exchange between CO2 and amine carbamate in nonaqueous solvent has been mathematically modelled in two ways. The height equivalent to a theoretical plate and steady-state separation, based on two models, have been obtained. If only the isotopic exchange between CO2 gas and amine carbamate solution is considered, the model can estimate the process performance for pressures close to the atmospheric one and room temperature. For process analysis at pressures higher than the atmospheric one and lower temperatures, a two-step model has been used. Using both models the effects of pressure rising have been studied. (authors)

323

On the paradox of pesticides  

CERN Document Server

The paradox of pesticides was observed experimentally, which says that pesticides may dramatically increase the population of a pest when the pest has a natural predator. Here we use a mathematical model to study the paradox. We find that the timing for the application of pesticides is crucial for the resurgence or non-resurgence of the pests. In particular, regularly applying pesticides is not a good idea as also observed in experiments. In fact, the best time to apply pesticides is when the pest population is reasonably high.

Li, Y Charles

2013-01-01

324

Residuos de plaguicidas en aguas para consumo humano en una comunidad agrícola del estado Mérida, Venezuela / Pesticide residues in drinking water of an agricultural community in the state of Mérida, Venezuela  

Scientific Electronic Library Online (English)

Full Text Available SciELO Venezuela | Language: Spanish Abstract in spanish El objetivo del presente trabajo fue determinar la presencia de plaguicidas en agua potable, provenientes de seis acueductos en una región de intensa actividad agrícola del Estado Mérida, Venezuela. El estudio fue realizado durante cuatro semanas continuas, entre mayo y junio de 2008. Los residuos d [...] e plaguicidas fueron analizados mediante extracción en fase sólida y HPLC con detector de arreglo de diodos. El método SPE-HPLC-DAD cumplió con los criterios de validación analítica: linealidad (R²: 0,9840-0,9999), precisión (coeficiente de variabilidad inter-día 1,47-6,25%), exactitud (desviación estándar relativa 0,9-9,20%) y sensibilidad (límite de detección ? 0,012 µg/L; límite de cuantificación ? 0,030 µg/L, excepto mancozeb con 0,400 µg/L). Siete de los trece plaguicidas seleccionados tienen un porcentaje de recuperación entre 100% y 70%, el resto, entre 61% y 37%. En 72 muestras analizadas, se detectaron diez plaguicidas de los grupos químicos: organofosforados, carbamatos, triazinas y derivados de urea. Los plaguicidas con mayor frecuencia de detección fueron: carbofuran y atrazina (39%), malation (25%), dimetoato y metribuzin (19%). Los plaguicidas que se encontraron en niveles más altos fueron: diazinon (26,31 µg/L), metamidofos (10,99 µg/L), malation (2,03 µg/L) y mancozeb (1,27 µg/L). Los niveles de plaguicidas no superaron los valores máximos permitidos por la Legislación Venezolana, sin embargo, fueron superiores al nivel máximo permitido por la Unión Europea y EPA-USA. Este estudio demuestra la urgente necesidad de hacer un monitoreo sistemático de la calidad del agua para consumo humano en las regiones de alta productividad agrícola. Abstract in english The aim of this study was to determine the presence of pesticides in drinking water from six aqueducts in a region of intense agricultural activity in the state of Merida, Venezuela. The study was conducted for four continuous weeks, between May and June 2008. Pesticide residues were analyzed by sol [...] id phase extraction (SPE) and liquid chromatography (HPLC) with diode array detector (DAD). The method SPE-HPLC-DAD met the criteria of analytical validation, with good linearity (R²: 0.9840 to 0.9999), precision (coefficient of inter-day variability from 1.47 to 6.25%), accuracy (relative standard deviation 0.9 to 9.20%) and sensitivity (LOD ? 0.012 µg/L; LOQ ? 0.030 µg/L, except mancozeb with 0.400 µg/L). Seven of the thirteen selected pesticides have a recovery rate between 100% and 70%, the rest between 61% and 37%. Ten pesticides of the following chemical groups, were detected in 72 samples analyzed: organophosphates, carbamates, triazines and urea derivatives. The pesticides with the highest frequency of detection were: carbofuran and atrazine (39%), malathion (25%), dimethoate and metribuzin (19%). The pesticides found at high levels were diazinon (26.31 µg/L), methamidophos (10.99 µg/L), malathion (2.03 µg/L) and mancozeb (1.27 µg/L). Pesticide levels did not exceed the maximum allowed by Venezuelan law, however, according to international standards (EU and EPA-USA) values were above the maximum permissible levels. This study demonstrates the urgent need for systematic monitoring of the quality of water for human consumption in regions of high agricultural productivity.

Mery Elisa, Flores-García; Yuri, Molina-Morales; Alirio, Balza-Quintero; Pedro Rafael, Benítez-Díaz; Leticia, Miranda-Contreras.

2011-12-01

325

A Test House Study of Pesticides and PesticideDegradation Products Following an Indoor Application  

Science.gov (United States)

Preexisting pesticide degradates are a concern for pesticide biomonitoring studies as exposure to them may result in overestimation of pesticide exposure. The purpose of this research was to determine whether there was significant formation and movement, of pesticide degradates o...

326

Pesticides water decontamination in oxygen-limited conditions.  

Science.gov (United States)

This study was undertaken to develop a laboratory bioreactor, with a functioning principle similar with that of biobed systems but working in oxygen-limited conditions, suitable for decontaminating wastewater mixtures with pesticides. The system is composed by two cylindrical plastic containers. The first one, where the pesticides solution is collected, is open, whereas the second one, where the biomass is disposed, is closed. The pesticides solution was pumped at the biomass surface and subsequently recollected and disposed in the first container. Four pesticides with different physical-chemical characteristics were tested. The results obtained showed a relatively good capacity of the developed prototype to decontaminate waste water containing the mixture of pesticides. The time of the experiment, the number of cycles that the solution made in the system and the environmental temperature have a significantly influence for the decontamination of acetochlor and chlorpyrifos whereas for the decontamination of terbuthylazine and metalaxyl no significant influence was observed. Even if the present prototype could represent a valid solution to manage the water pesticides residues in a farm and to increase the confidence of bystanders and residents, the practical difficulties when replacing the biomass could represent a limit of the system. PMID:23688230

Suciu, Nicoleta Alina; Ferrari, Federico; Vasileiadis, Sotirios; Merli, Annalisa; Capri, Ettore; Trevisan, Marco

2013-01-01

327

Investigations of primary and secondary amine carbamate stability by 1H NMR spectroscopy for post combustion capture of carbon dioxide  

International Nuclear Information System (INIS)

Highlights: ? Carbamate stability constants of series of amines have been measured at (288 to 318) K. ? Standard molar enthalpies and entropies have been determined by van’t Hoff analyses. ? A ?Hmo-?Smo plot for carbamate formation gives a linear relationship. ? This relationship provides a guide for the selection of amines for PCC applications. ? Stereochemical effects and intramolecular H-bonding affect carbamate formation. - Abstract: Carbamate formation is one of the major chemical reactions that can occur in solution in the capture of CO2 by amine-based solvents, and carbamate formation makes a significant enthalpy contribution to the absorption-desorption of CO2 that occurs in the absorber/stripper columns of the PCC process. Consequently, the formation of carbamates of selected series of primary and secondary amines over the temperature range (288 to 318) K has been investigated by equilibrium 1H NMR studies, and the stability constants (K9) for the equilibrium: RNH2+HCO3-?K9RNHCOO-+H2O are reported. van’t Hoff analyses have resulted in standard molar enthalpies, ?Hmo, and entropies, ?Smo, of carbamate formation. A ?Hmo-?Smo plot generates a linear correlation for carbamate formation (providte formation (providing a mean standard molar free energy, ?Gmo, for carbamate formation of about ?7 kJ · mol?1), and this relationship helps provide a guide to the selection of an amine(s) solvent for CO2 capture, in terms of enthalpy considerations. A linear ?Hmo-?Smo plot also occurs for carbamate protonation. The formation of the carbamates has been correlated with systematic changes in composition and structure, and steric effects have been identified by comparing molecular geometries obtained using density functional B3LYP/6-311++G(d,p) calculations. Trends in steric effects have been identified in the series of compounds monoethanolamine (MEA), 1-amino-2-propanol, 2-amino-1-propanol (AP) and 2-amino-2-methyl-1-propanol (AMP). In the case of 2-piperidinemethanol, 2-piperidineethanol and 3-piperidinemethanol, strong intramolecular hydrogen bonding is shown to be the likely cause for lack of carbamate formation, and in the ring systems of pyrrolidine, morpholine, piperidine and thiomorpholine trends in carbamate formation (as given by K9) have been correlated with the internal ring angle at the amine nitrogen, as well as the planarity of the environment around the nitrogen atom.

328

PESTICIDE ROOT ZONE MODEL  

Science.gov (United States)

PRZM3 is a modeling system that links two subordinate models - PRZM and VADOFT to predict pesticide transport and transformation down through the crop root and unsaturated zone. PRZM3 includes modeling capabilities for such phenomena as soil temperature simulation, vo...

329

Epigenetics and pesticides.  

Science.gov (United States)

Pesticides, a wide class of environmental contaminants, may cause both acute and delayed health effects in exposed subjects. These effects can range from simple irritation of the skin and eyes to more severe effects such as affecting the nervous system, the reproductive system and cancer. The molecular mechanisms underlying such effects are still under investigation. Epigenetics is the study of heritable changes in gene expression that occur without a change in the DNA sequence. Several epigenetic mechanisms, including DNA methylation, histone modifications and microRNA expression, can be triggered by environmental factors. We review current evidences indicating that epigenetic modifications may mediate pesticide effects on human health. In vitro, animal, and human investigations have identified several classes of pesticides that modify epigenetic marks, including endocrine disruptors, persistent organic pollutants, arsenic, several herbicides and insecticides. Several investigations have examined the effects of environmental exposures and epigenetic markers, and identified toxicants that modify epigenetic states. These modifications are similar to the ones found in pathological tissue samples. In spite of the current limitations, available evidence supports the concept that epigenetics holds substantial potential for furthering our understanding of the molecular mechanisms of pesticides health effects, as well as for predicting health-related risks due to conditions of environmental exposure and individual susceptibility. PMID:23380243

Collotta, M; Bertazzi, P A; Bollati, V

2013-05-10

330

Hollow-fiber liquid-phase microextraction for the determination of pesticides and metabolites in soils and water samples using HPLC and fluorescence detection.  

Science.gov (United States)

A new and simple method has been developed for the determination of a group of four benzimidazole pesticides (carbendazim/benomyl, thiabendazole, and fuberidazole), a carbamate (carbaryl), and an organophosphate (triazophos), together with two of their main metabolites (2-aminobenzimidazole, metabolite of carbendazim/benomyl, and 1-naphthol, metabolite of carbaryl) in soils. First, an ultrasound-assisted extraction (UAE) was performed, followed by evaporation and reconstitution in water. Then, extraction and preconcentration of the analytes was accomplished by two-phase hollow-fiber liquid-phase microextraction (HF-LPME) using 1-octanol as extraction solvent. Parameters that affect the extraction efficiency in HF-LPME technique (organic solvent, pH of the sample, extraction time, stirring speed, temperature, and ionic strength) were deeply investigated. Optimum HF-LPME conditions involved the use of a 2.0 cm polypropylene fiber filled with 1-octanol to extract 10 mL of an aqueous soil extract at pH 9.0 containing 20% (v/v) of NaCl for 30 min at 1440 rpm. Separation and quantification was achieved by HPLC with fluorescence detection (FD). The proposed optimum UAE-HF-LPME-HPLC-FD methodology provided good calibration, precision, and accuracy results for two soils of different physicochemical properties. LODs were in the range 0.001-6.94 ng/g (S/N = 3). With the aim of extending the validation, the HF-LPME method was also applied to different types of waters (Milli-Q, mineral and run-off), obtaining LODs in the range 0.0002-0.57 ?g/L. PMID:22821496

Asensio-Ramos, María; Hernández-Borges, Javier; González-Hernández, Guillermo; Rodríguez-Delgado, Miguel Ángel

2012-07-01

331

Comparative study of human and mouse pregnane X receptor agonistic activity in 200 pesticides using in vitro reporter gene assays  

International Nuclear Information System (INIS)

The nuclear receptor, pregnane X receptor (PXR), is a ligand-dependent transcription factor that regulates genes involved in xenobiotic metabolism. Recent studies have shown that PXR activation may affect energy metabolism as well as the endocrine and immune systems. In this study, we characterized and compared the agonistic activities of a variety of pesticides against human PXR (hPXR) and mouse PXR (mPXR). We tested the hPXR and mPXR agonistic activity of 200 pesticides (29 organochlorines, 11 diphenyl ethers, 56 organophosphorus pesticides, 12 pyrethroids, 22 carbamates, 12 acid amides, 7 triazines, 7 ureas, and 44 others) by reporter gene assays using COS-7 simian kidney cells. Of the 200 pesticides tested, 106 and 93 activated hPXR and mPXR, respectively, and a total of 111 had hPXR and/or mPXR agonistic activity with greater or lesser inter-species differences. Although all of the pyrethroids and most of the organochlorines and acid amides acted as PXR agonists, a wide range of pesticides with diverse structures also showed hPXR and/or mPXR agonistic activity. Among the 200 pesticides, pyributicarb, pretilachlor, piperophos and butamifos for hPXR, and phosalone, prochloraz, pendimethalin, and butamifos for mPXR, acted as particularly potent activators at low concentrations in the order of 10-8-10-7 M. In addition, we found that several organophosphorus oxon- and pyributicarb oxon-metabolites decreased PXR activation potency compared to their parent compounds. These results suggest that a large number of structurally diverse pesticides and their metabolites possess PXR-mediated transcriptional activity, and their ability to do so varies in a species-dependent manner in humans and mice.

332

Environmental impact of pesticides after sewage treatment plants removal in four Spanish Mediterranean rivers  

Science.gov (United States)

The re-use of sewage treatment plant (STP) effluents is currently one of the most employed strategies in several countries to deal with the water shortage problem. Some pesticides are bio-accumulative and due to their toxicity they can affect non-target organisms, especially in the aquatic ecosystems, threating their ecological status. Despite these facts, and to our knowledge, there are few peer-reviewed articles that report concentrations of pesticides in Spanish STPs. This work presents the results of an extensive survey that was carried out in October of 2010 in 15 of the STPs of Ebro, Guadalquivir, Jucar and Llobregat rivers in Spain. Forty-three currently used pesticides, belonging to anilide, neonicotinoid, thiocarbamate, acaricide, juvenile hormone mimic, insect growth regulator, urea, azole, carbamate, chloroacetanilide, triazine and organophosphorus, have been monitored. Integrated samples of influent and effluent, and dehydrated, lyophilized sludge from 15 STPs located along the rivers were analyzed for pesticide residues. With these data, removal efficiencies are also calculated. Extraction of water samples was performed through Solid Phase Extraction (SPE) and sludge samples were extracted using the QuEchERS method. Pesticide determination was carried out using Liquid Chromatograph - tandem Mass Spectrometry (LC-MS/MS). Recoveries ranged from 48% to 70%, in water samples, and from 40 to 105 %, in sludge samples. The limits of quantification were 0.01-5 ng L-1 for the former, and 0.1-5.0 ng g-1 for the latter. In terms of frequency of detection, 31 analytes were detected in influent, 29 in effluent and 11 in sludge samples. Organophosphorus pesticides were the most frequently detected in all wastewater samples, but azole, urea, triazine, neonicotinoid and the insect growth regulator were also commonly found. Imazalil revealed the maximum concentration in wastewater samples from all rivers except the Guadalquivir, in which diuron presented the maximum one. Eleven pesticides including five organophosphorus, two azoles, one triazine, one chloroacetanilide, one juvenile hormone mimic and one acaricide were detected in the sludge samples. Accordingly, organophosphorus were the most frequently detected pesticides in the sludge samples, but the highest concentration was observed for imazalil. The higher concentration of this azole in the influent and their possible stronger adsorption may be the reason for their higher concentration in the sludge samples. The removal efficiency of pesticides was calculated from the analyte concentration in influent (Cin) and effluent (Cef): [(Cin-Cef)/Cin] x 100%. The removal of organophosporus ranged from -810,47 to 93,11%, meanwhile azoles and ureas were not removed in the STPs. The poor elimination of pesticides by sewage treatment plants presented in this study could be related to the treatment process used, hydraulic and solid retention times, besides the dilution and temperature of the raw sewage and the plant's configuration. These poor efficiencies are responsible of the high pesticides concentration (e.g.diuron) found in some effluents, which may endanger water quality of the ecosystem when they are re-used or directly discharged into the river. In fact, with respect to the Maximum Allowable Concentrations (MAC) stipulated by the Directive 2008/105/EC for pesticides in inland and other surface waters (Council of the European Communities, 2008), diuron exceeded these limits. Nevertheless, it is important to emphasize that, even though, the pesticides concentrations measured were relatively low (according to directives); this study analysed just some of them. A wide variety of other compounds, including other pesticides and pesticides transformation products, may contribute to the bad quality of the water ecosystems. Acknowledgements: This work has been supported by by the Spanish Ministry of Science and Innovation through the project Consolider-Ingenio 2010 (CSD2009), as well as by this Ministry and the European Regional Development Funds (ERDF) (projects CGL2011-29703-C02-0

Campo, Julian; Masiá, Ana; Blasco, Cristina; Picó, Yolanda; Andreu, Vicente

2013-04-01

333

Pesticide poisoning trend analysis of 13 years: a retrospective study based on telephone calls at the National Poisons Information Centre, All India Institute of Medical Sciences, New Delhi.  

Science.gov (United States)

The study was designed to analyze the incidence and pattern of pesticide poisoning calls reported to the National Poisons Information Centre (NPIC), AIIMS, New Delhi and highlight the common classes of pesticides involved in poisoning. The telephone calls received by the Centre during the thirteen year period (1999-2012) were entered into a preset proforma and then into a retrievable database. A total of 4929 calls of pesticide poisoning were recorded. The data was analyzed with respect to age, gender, mode and type of poisoning. The age ranged from 1 to 65 years with the preponderance of males (M = 62.19%, F = 37.80%). The age group mainly involved in poisoning was 18-35 years. While 59.38% calls pertained to household pesticides, 40.61% calls related to agricultural pesticides. The common mode of poisoning was intentional (64.60%) followed by accidental (34.40%) and unknown (1%). Amongst the household pesticides, the highest number of calls were due to pyrethroids (26.23%) followed by rodenticides (17.06%), organophosphates (6.26%), carbamates (4.95%) and others (4.86%). In agricultural pesticides group, the organophosphates (9.79%) ranked the first followed by, aluminium phosphide (9.65%), organochlorines (9.31%), pyrethroids (3.87%), herbicides, weedicides and fungicides (3.20%), ethylene dibromide (2.82%), and others (1.70%). The data analysis shows a high incidence of poisoning due to household pesticides as compared to agricultural pesticides, clearly emphasizing the need for creating awareness and education about proper use and implementation of prevention programmes. PMID:24485423

Peshin, Sharda Shah; Srivastava, Amita; Halder, Nabanita; Gupta, Yogendra Kumar

2014-02-01

334

Preparation of carbon-14 and tritium labelled 2-sec-butylphenyl N-methyl carbamate (BPMC)  

International Nuclear Information System (INIS)

BPMC is a widely used, carbamate type insecticide which was prepared both in 14C and tritium labelled forms for metabolic pathway investigations. The specific activity of the [14C]BPMC was 26.7 mCi/mmol and that of the [3H]BPMC was 58 Ci/mmol. (author)

335

Synthesis of [carbonyl-14C]labeled carbonate and carbamate esters  

International Nuclear Information System (INIS)

A two-step synthesis of three carbonate and four carbamate esters labeled at the carbonyl with carbon-14 is described. The method utilizes the readily available [14C]-phosgene which is first converted to an isolable [14C]-labeled alkyl or aryl chloroformate and subsequently reacted with the appropriate alcohol or amine to give the corresponding ester. (author)

336

FUNGICIDE METHYL 2-BENZIMIDAZOLE CARBAMATE CAUSES INFERTILITY IN MALE SPRAGUE-DAWLEY RATS  

Science.gov (United States)

A serial breeding technique was used to evaluate the fertility of male Sprague-Dawley rats after exposure to the fungicide carbendazim (methyl 2-benzimidazole carbamate)(C). Proven-fertile male rats (90 d old) received 10 daily doses of corn oil or C(400 mg/kg/d) peroral. Each ma...

337

Carbamate derivatives and sesquiterpenoids from the South China Sea gorgonian Melitodes squamata  

OpenAIRE

Five carbamate derivatives, obtucarbamates C and D (1, 2), dimethyl ((carbonylbis(azanediyl))bis(2-methyl-5,1-phenylene))dicarbamate (3), obtucarbamates A and B (4, 5), and four aromadendrane-type sesquiterpenoids, (+)-4?-N-methenetauryl-10?-methoxy-1?,5?,6?,7?-aromadendrane (6), (?)-4?-N-methenetauryl-10?-methoxy-1?,5?,6?,7?-aromadendrane (7), (?)-4?,10&...

Li-Si Huang; Fei He; Hui Huang; Xiao-Yong Zhang; Shu-Hua Qi

2012-01-01

338

Synthesis of di-ethyl-di-thio-carbamates on the base of 1,3-dioxolane  

International Nuclear Information System (INIS)

In this work authors present the results of investigations obtained at studying of reaction of nucleophilic substitution of chlor atom in 2,2-di-alkyl-4-chlor-methyl-1,3-dioxolane on anion of di-ethyl-di-thio-carbamate

339

Computational study of structural properties of lithium cation complexes with carbamate-modified disiloxanes.  

Science.gov (United States)

Lithium cation solvation structures [Li(S)(n=1-4)](+) with ligands of cyclic or noncyclic carbamate-modified disiloxanes are optimized at B3LYP level of theory and compared to their corresponding simplified carbamates and to the organic carbonates ethylene carbonate (EC) and dimethyl carbonate (DMC). The electrostatic potentials (ESP) of these investigated carbonyl-containing solvents are mapped on the electron density surface. The maximum ESP is located at the C=O-oxygen, whereas the disiloxane functionality represents an unpolar residue. Natural Bond Orbitals (NBO) analysis reveals strong n(N) ??(C[double bond, length as m-dash]O) donor-acceptor interactions in carbamates which outrun dipolar properties. As a result, higher total binding energies (?E(B)) for solvation of Li(+) in carbamates (-148 kcal mol(-1)) are found than for carbonates (-137 kcal mol(-1)). Furthermore, the disiloxane moiety with its Si-O bond is stabilized by n(O) ??*(Si-C) hyperconjugation that provides additional electron density to a nearby SiCH3 methyl group thus supporting an additional SiCH2-H...Li(+) coordination. The formation of all investigated solvation structures is exothermic. Owing to steric hindrance of noncyclic carbonyl-containing ligands and the bulky disiloxane functionality, the solvation structure [Li(S)3](+) is the preferred structure according to Gibbs free energy ?G(B) results. PMID:24914737

Jeschke, Steffen; Wiemhöfer, Hans-Dieter; Mück-Lichtenfeld, Christian

2014-07-21

340

TIME-COURSE OF ACUTE NEUROTOXICITY PRODUCED BY N-METHYL CARBAMATES IN PREWEANLING RATS.  

Science.gov (United States)

N-methyl carbamate insecticides are reversible inhibitors of central and peripheral acetylcholinesterease (ChE). Despite their widespread and long-term use, we could find no studies of a systematic comparison of neurotoxicity in young animals across this group of chemicals. To ...

341

Organophosphorus and carbamates residues in milk and feedstuff supplied to dairy cattle / Resíduos de praguicidas organofosforados e carbamatos em leite e alimentação animal de propriedades leiteiras  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese Considerando os efeitos tóxicos, agudos e crônicos, para a saúde humana e animal, causados por resíduos de praguicidas em alimentos, este trabalho teve como objetivo a identificação e quantificação por cromatografia gasosa (CG) de resíduos de praguicidas organofosforados (OF) e carbamatos (CB) no le [...] ite cru, nos componentes da alimentação e água dos animais. Foram coletadas 30 amostras de leite cru da região agreste de Pernambuco e ao mesmo tempo eram coletadas amostras de alimentação e água ofertada aos animais em lactação de cada propriedade, totalizando 109 amostras de alimentação e 38 amostras de água. Das 30 amostras de leite analisadas, seis (20%) estavam contaminadas por resíduos de OF, cinco (16,7%) por resíduos de CB e uma amostra por ambos os praguicidas. Das 109 amostras de alimentação ofertada aos animais coletadas, 48 foram analisadas, com 15 amostras (31,25%) apresentando resíduos de OF, seis amostras (12,50%) contaminadas por resíduos de CB e uma amostra positiva para ambos os praguicidas. Das 16 amostras de água analizadas, seis (37,50%) estavam contaminadas por resíduos de OF e nenhuma apresentou resíduos de CB. Em quatro propriedades leiteiras os praguicidas detectados no leite foram compatíveis com o princípio ativo detectado na alimentação e/ou na água ofertada aos animais, sugerindo uma possível fonte de contaminação, mas não a única. Abstract in english Considering acute and chronic toxicity effects on human and animal health caused by pesticide residues in food, this study aimed to analyze organophosphorate (OP) and carbamate (CB) in feedstuff and water destined for dairy cattle, as well as in the milk produced by these animals, through gas chroma [...] tography (GC). In the Agreste region of Pernambuco, Brazil, 30 raw milk samples and all components of the animals' diet were collected from several farms. Out of the 30 milk of milk analyzed, six (20%) were contaminated with OP, five (16.7%) with CB, and one sample with both pesticides. From 48 analyzed feed samples, 15 (31.25%) were contaminated with residues of OP, six (12.50%) with CB, and one sample was contaminated with both pesticides. Out of 16 water samples analyzed, six (37.50%) were contaminated with OP residues, but non with CB. In four dairy farms the pesticides detected in milk were compatible with the active principles found in water and/or foodstuff, suggesting them to be the source of contamination.

Rafael, Fagnani; Vanerli, Beloti; Ana Paula P., Battaglini; Karen da S., Dunga; Ronaldo, Tamanini.

2011-07-01

342

Preliminary risk assessment of common-use pesticides using PRIMET and PERPEST pesticide risk models in a semi-arid subtropical region  

Scientific Electronic Library Online (English)

Full Text Available SciELO South Africa | Language: English Abstract in english The pesticide risk in agriculture in developing countries has not been adequately studied due to the extent and fate of pesticides in the environment often being unknown. South Africa is a country that has significant pressure on its freshwater and agricultural resources, which increases the possibi [...] lity of pesticide effects. Thus, the aim of this study was to evaluate the use of the PRIMET (Pesticide Risks in the Tropics to Man, Environment and Trade) and PERPEST (Predicting the Ecological Risk of PESTicides) models to predict pesticide exposure and effects on aquatic ecosystems due to spray drift. Vaalharts Irrigation Scheme is situated in the Northern Cape Province and receives water from the Vaal River for 43 000 ha of agricultural land. Crops in the area mostly consist of wheat, maize and groundnuts. Data gathered through household surveys with farmers were used in PRIMET as a first-tier estimate of the potential risk of the pesticides. The Predicted Effect Concentrations (PEC) calculated for the pesticides indicating a possible to definite risk were then used as input for PERPEST. PERPEST is a higher-tier model that predicts the potential effects of a pesticide on various grouped endpoints in the aquatic environment. The PRIMET results indicated most pesticides posed no risk to the environment, except the pyrethroid, deltamethrin. The ETR for deltamethrin indicated a possible to definite risk to the aquatic environment. The PERPEST results for deltamethrin indicated a high probability of clear effects on insects, micro- and macro-crustacean communities, with a lower probability for rotifers, algae, macrophytes and fish. PRIMET and PERPEST provided valid estimates of risk for pesticides and could be used effectively in South Africa.

W, Malherbe; JHJ, van Vuren; V, Wepener.

343

A novel optimised and validated method for analysis of multi-residues of pesticides in fruits and vegetables by microwave-assisted extraction (MAE)-dispersive solid-phase extraction (d-SPE)-retention time locked (RTL)-gas chromatography-mass spectrometry with Deconvolution reporting software (DRS).  

Science.gov (United States)

A rapid, effective and ecofriendly method for sensitive screening and quantification of 72 pesticides residue in fruits and vegetables, by microwave-assisted extraction (MAE) followed by dispersive solid-phase extraction (d-SPE), retention time locked (RTL) capillary gas-chromatographic separation in trace ion mode mass spectrometric determination has been validated as per ISO/IEC: 17025:2005. Identification and reporting with total and extracted ion chromatograms were facilitated to a great extent by Deconvolution reporting software (DRS). For all compounds LOD were 0.002-0.02mg/kg and LOQ were 0.025-0.100mg/kg. Correlation coefficients of the calibration curves in the range of 0.025-0.50mg/kg were >0.993. To validate matrix effects repeatability, reproducibility, recovery and overall uncertainty were calculated for the 35 matrices at 0.025, 0.050 and 0.100mg/kg. Recovery ranged between 72% and 114% with RSD of <20% for repeatability and intermediate precision. The reproducibility of the method was evaluated by an inter laboratory participation and Z score obtained within ±2. PMID:25214130

Satpathy, Gouri; Tyagi, Yogesh Kumar; Gupta, Rajinder Kumar

2011-08-01

344

Knowledge, Attitudes, Practices and Biomonitoring of Farmers and Residents Exposed to Pesticides in Brazil  

Directory of Open Access Journals (Sweden)

Full Text Available In this study, the knowledge, attitudes and practices regarding pesticide use and the levels of exposure of farmers and residents to organophosphorous and/or carbamates pesticides were evaluated in two rural settings in Brazil. A questionnaire was completed by 112 farm workers aged ?18 years. Almost all farmers acknowledged that pesticides were potentially harmful to their health (87.5%; however, over half rarely (48.2% or never (7.2% used personal protective devices (PPDs. An association was found (p = 0.001 between the work regimen and the use of PPDs, with more frequent equipment use among hired laborers than those involved in family agriculture. A significant correlation (p = 0.027 was found between the reporting of adverse symptoms and the use of backpack sprayers. Mean AChE activities of farmers (n = 64 and residents (n = 18 during the exposure and non-exposure periods were significantly lower than their control groups. Mean BChE activities of farmers and residents were significantly lower than their controls during the exposure period. Among the 60 farmers that had blood samples collected in both the exposure and non-exposure (baseline periods, 10 (16.7% had AChE depletion of over 30% during the exposure period compared with the baseline level. Six residents living on the same farms also presented this depletion. AChE was over 30% higher than the baseline level for 19 farmers (31.7%, indicating a reboot effect. Special education programs are needed in these regions to promote the safe use of pesticides in the field to decrease the risks from exposure to pesticides for farmers, and from secondary exposure to these compounds for their families.

Eloisa Dutra Caldas

2012-08-01

345

tert-Butyl N-benzyl-N-[4-(4-fluoro­benzoyl­meth­yl)-2-pyrid­yl]carbamate  

OpenAIRE

In the crystal structure of the title compound, C25H25FN2O3, the pyridine ring makes dihedral angles of 75.1?(3), 39.4?(3) and 74.6?(3)° with the phenyl ring, the carbamate plane and the 4-fluoro­phenyl ring, respectively. The phenyl ring makes dihedral angles of 77.2?(3) and 23.6?(3)° with the carbamate plane and the 4-fluoro­phenyl ring, respectively. The 4-fluoro­phenyl ring is perpendicular to the carbamate plane, the dihedral angle between them being 89.5?(3)°.

Koch, Pierre; Schollmeyer, Dieter; Laufer, Stefan

2008-01-01

346

Occurrence and distribution of pesticides in the province of Bologna, Italy, using honeybees as bioindicators.  

Science.gov (United States)

Samples of honeybees (Apis mellifera, n = 92) from 14 beehive monitoring stations located in 3 townships in the province of Bologna were analyzed from April to October 2000. The concentration of 32 organophosphorus pesticides and 5 carbamates was determined through liquid-liquid extraction followed by gas chromatography with a nitrogen-phosphorus detector and liquid chromatography coupled to mass spectrometry using atmospheric pressure chemical ionization in positive and negative ion modes. The most contaminated samples were from Granarolo Emilia where cereals (wheat, sorghum, and corn), sugar beets, and potatoes are the main agriculture products. Thirty-five pesticides were detected, with organophosphorus being the most abundant ones. Malathion was detected in 58% of the samples (mean level 0.360 mg/kg) followed by fenithrothion in 53% of the samples (mean level 0.544 mg/kg) and pirimiphos methyl in 48% of the samples (mean level 0.006 mg/kg). Temporal trends showed that the maximum detection frequency occurred in late spring and was associated with the use of treatment products and less rainfall. The obtained results demonstrated the feasibility of using honeybees for assessing pesticide exposure in agriculture settings. PMID:15499498

Ghini, S; Fernández, M; Picó, Y; Marín, R; Fini, F; Mañes, J; Girotti, S

2004-11-01

347

Influence of a carbamate pesticide on growth, respiration (14C)-carbon metabolism and symbiosis of a Rhizobium sp  

International Nuclear Information System (INIS)

Addition of aldicarb (2 methyl-2(methyl thio) propionaldehyde-O-methyl carbamoyl oxime) in the growth medium enhanced the growth of Rhizobium sp. (cowpea group) at 2ppm level while an inhibition was observed at the normal (5 ppm) and higher (10 ppm) concentrations. Respiration of the cells was also inhibited by 5 and 10 ppm levels of the chemical eventhough a stimulation was observed at 2 ppm (lower) concentration. The insecticide, when incorporated at 5 and 10 ppm levels in the medium increased the 14C-glucose incorporation and considerably altered the assimilation of the radioactive carbon in different fractions of rhizobium cells. Soil application of this insecticide (Temik 10 G) reduced the number of nodules formed and the total nitrogen content in cowpea plants inoculated with the Rhizobium sp. but enhanced the dry matter production of cowpea plants. (Auth.)

348

76 FR 12877 - Fomesafen; Pesticide Tolerances  

Science.gov (United States)

...simulation model, the Pesticide Root Zone Model/ Exposure...water models used in pesticide exposure assessment...vulnerable North Carolina soil using a soybean cropping...effects of a particular pesticide's residues and...fomesafen primarily impacts the parameters of...

2011-03-09

349

33 CFR 274.4 - Pesticide management.  

Science.gov (United States)

...Personnel actions. Pesticide duties will...following established health and safety practices and...restricted-use pesticides. (g) Exposure...protection from pesticide hazards. Basic health and safety practices and...

2010-07-01

350

Soil column leaching of pesticides.  

Science.gov (United States)

In this review, I address the practical and theoretical aspects of pesticide soil mobility.I also address the methods used to measure mobility, and the factors that influence it, and I summarize the data that have been published on the column leaching of pesticides.Pesticides that enter the unsaturated soil profile are transported downwards by the water flux, and are adsorbed, desorbed, and/or degraded as they pass through the soil. The rate of passage of a pesticide through the soil depends on the properties of the pesticide, the properties of the soil and the prevailing environmental conditions.Because large amounts of many different pesticides are used around the world, they and their degradates may sometimes contaminate groundwater at unacceptable levels.It is for this reason that assessing the transport behavior and soil mobility of pesticides before they are sold into commerce is important and is one indispensable element that regulators use to assess probable pesticide safety. Both elementary soil column leaching and sophisticated outdoor lysimeter studies are performed to measure the leaching potential for pesticides; the latter approach more reliably reflects probable field behavior, but the former is useful to initially profile a pesticide for soil mobility potential.Soil is physically heterogeneous. The structure of soil varies both vertically and laterally, and this variability affects the complex flow of water through the soil profile, making it difficult to predict with accuracy. In addition, macropores exist in soils and further add to the complexity of how water flow occurs. The degree to which soil is tilled, the density of vegetation on the surface, and the type and amounts of organic soil amendments that are added to soil further affect the movement rate of water through soil, the character of soil adsorption sites and the microbial populations that exist in the soil. Parameters that most influence the rate of pesticide mobility in soil are persistence (DT50) of the pesticide, and its sorption/desorption(Koc) characteristics. These parameters may vary for the same pesticide from geographic site-to-site and with soil depth. The interactions that normally occur between pesticides and dissolved organic matter (DOM) or WDC are yet other factors that may complicate pesticide leaching behavior.The soil mobility of pesticides is normally tested both in the laboratory and in the field. Lab studies are initially performed to give researchers a preliminary appraisal of the relative mobility of a pesticide. Later, field lysimeter studies can be performed to provide more natural leaching conditions that emulate the actual field use pattern. Lysimeter studies give the most reliable information on the leaching behavior of a pesticide under field conditions, but these studies are time-consuming and expensive and cannot be performed everywhere. It is for this reason that the laboratory soil column leaching approach is commonly utilized to profile the mobility of a pesticide,and appraise how it behaves in different soils, and relative to other pesticides.Because the soil structure is chemically and physically heterogenous, different pesticide tests may produce variable DT50 and Koc values; therefore, initial pesticide mobility testing is undertaken in homogeneously packed columns that contain two or more soils and are eluted at constant flow rates. Such studies are done in duplicate and utilize a conservative tracer element. By fitting an appropriate mathematical model to the breakthrough curve of the conservative tracer selected,researchers determine key mobility parameters, such as pore water velocity, the column-specific dispersion coefficient, and the contribution of non equilibrium transport processes. Such parameters form the basis for estimating the probable transport and degradation rates that will be characteristic of the tested pesticide. Researchers also examine how a pesticide interacts with soil DOM and WDC, and what contribution from facilitated transport to mobility is made as a result of the effects of

Katagi, Toshiyuki

2013-01-01

351

Resíduos de agrotóxicos em alimentos: uma preocupação ambiental global - Um enfoque às maçãs / Residues of pesticides in food: a global environmental preoccupation - Focussing on apples  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese [...] Abstract in english This paper describes the use of pesticides in agriculture. Research has shown that significant quantities of pesticide residues have been found in many types of foods. Thus, an overview is given of pesticide residue determinations in fruits and vegetables, with special attention to apples. The toxic [...] ity and the adverse effects possibly caused by the exposure of these compounds are alerting the scientific community to develop studies about the validation of analytical methods for multiresidue pesticide determination in these samples. This review shows that pesticide-residue determination in apples is becoming a very important and challenging issue.

Isabel Cristina Sales Fontes, Jardim; Juliano de Almeida, Andrade; Sonia Claudia do Nascimento de, Queiroz.

352

Resíduos de agrotóxicos em alimentos: uma preocupação ambiental global - Um enfoque às maçãs Residues of pesticides in food: a global environmental preoccupation - Focussing on apples  

Directory of Open Access Journals (Sweden)

Full Text Available This paper describes the use of pesticides in agriculture. Research has shown that significant quantities of pesticide residues have been found in many types of foods. Thus, an overview is given of pesticide residue determinations in fruits and vegetables, with special attention to apples. The toxicity and the adverse effects possibly caused by the exposure of these compounds are alerting the scientific community to develop studies about the validation of analytical methods for multiresidue pesticide determination in these samples. This review shows that pesticide-residue determination in apples is becoming a very important and challenging issue.

Isabel Cristina Sales Fontes Jardim

2009-01-01

353

Pesticide exposure assessment.  

Science.gov (United States)

Unintended, accidental, or unavoidable human exposures may result from pesticide use. Risk Characterization provides registrants, regulators, and the public a means to assess relative risks of pesticide use. Exposure Assessments are less standardized. Potential Dermal Exposure (PDE; mg/kg) is the amount of contact with the potential for dermal absorption (DA). Mixer/loader/applicator data developed using passive dosimetry and skin washing forms a Tier 1 Generic Database. If disqualifying estimates are obtained a more accurate estimate (Tier 2) may be developed from measurements of DA, clothing protection, and PDE under use conditions. Direct estimates of absorbed dose (Tier 3) require metabolic and kinetic data and biological monitoring. Harvesters and other persons who contact treated surfaces need reentry intervals to minimize acute and chronic exposure. Work tasks, dislodgeable foliar residue, and duration of exposure are the foundations for exposure-based, generic estimates of harvester PDE. PMID:8597123

Krieger, R I

1995-12-01

354

Radiation induced microbial pesticide  

International Nuclear Information System (INIS)

To control plant pathogenic fungi, 4 strains of bacteria (K1, K3, K4, YS1) were isolated from mushroom compost and hot spring. K4, K1, K3, YS1 strain showed wide antifungal spectrum and high antifungal activities against 13 kinds of fungi. Mutants of K1 and YS1 strains were induced by gamma-ray radiation and showed promising antifungal activities. These wild type and mutants showed resistant against more than 27 kinds of commercial pesticides among 30 kinds of commercial pesticides test particularly, YS1-1006 mutant strain showed resistant against hydrogen oxide. And mutants had increased antifungal activity against Botryoshaeria dothidea. These results suggested that radiation could be an useful method for the induction of functional mutants. (author)

355

Radiation induced microbial pesticide  

Energy Technology Data Exchange (ETDEWEB)

To control plant pathogenic fungi, 4 strains of bacteria (K1, K3, K4, YS1) were isolated from mushroom compost and hot spring. K4, K1, K3, YS1 strain showed wide antifungal spectrum and high antifungal activities against 13 kinds of fungi. Mutants of K1 and YS1 strains were induced by gamma-ray radiation and showed promising antifungal activities. These wild type and mutants showed resistant against more than 27 kinds of commercial pesticides among 30 kinds of commercial pesticides test particularly, YS1-1006 mutant strain showed resistant against hydrogen oxide. And mutants had increased antifungal activity against Botryoshaeria dothidea. These results suggested that radiation could be an useful method for the induction of functional mutants. (author)

Kim, Ki Yup; Lee, Young Keun; Kim, Jae Sung; Kim, Jin Kyu; Lee, Sang Jae

2000-01-01

356

Curious about pesticide action.  

Science.gov (United States)

The safe and effective use of pesticides requires knowledge of their mode of action in pests and adverse effects in nontarget organisms coupled with an understanding of their metabolic activation and detoxification. The author and his laboratory colleagues were privileged to observe, participate in, and sometimes influence these developments for the past six decades. This review considers contributions of the Berkeley and Madison laboratories to understanding insecticides acting at voltage-gated sodium and GABA-gated chloride channels and the nicotinic receptor and at serine hydrolases and other targets as well as the action of insecticide synergists and selected herbicides and fungicides. Some of the discoveries gave new probes, radioligands, photoaffinity labeling reagents, and understanding of reactive intermediates that changed the course of pesticide investigations and related areas of science. The importance of coupling mode of action with metabolism and design with serendipity is illustrated with a wide variety of chemotypes. PMID:20698709

Casida, John E

2011-04-13

357

Pesticide residues in eagles  

Science.gov (United States)

Bald and golden eagles found sick or dead in 18 States and Canada during 1964-1965 were analyzed for pesticide residues. Residues in bald eagles were considerably higher than in golden eagles. Residues of DDE, DDD, and dieldrin were detected in all samples of bald eagle carcasses; other compounds found, less frequently were heptachlor epoxide, endrin, and DCBP, a metabolite of DDT. DDE was detected in all samples of golden eagle carcasses; DDD, DDT, dieldrin, and heptachlor epoxide were detected less frequently.

Reichel, W.L.; Cromartie, E.; Lamont, T.G.; Mulhern, B.M.; Prouty, R.M.

1969-01-01

358

Determinação de carbamato de etila em aguardentes de cana por CG-EM Determination of ethyl carbamate in sugar cane spirits by GC-MS  

Directory of Open Access Journals (Sweden)

Full Text Available A simple, specific and sensitive GC-MS procedure with ion m/z 62 was validated for the determination of ethyl carbamate (EC in spirits. It exhibited linearity over the concentration of 30 to 600 ?g/L with 30 ?g/L limit of quantification. EC was detected in 70 of the 71 samples analyzed with levels from 33 to 2609 ?g/L (mean level = 893 ?g/L. 35% of the samples contained 500 to 1000 ?g/L and 23% contained 150 to 500 and 1000 to 1500 ?g/L. No significant correlation was found between EC and the levels of copper, pH and alcohol content of the samples.

Renata Adriana Labanca

2008-01-01

359

Determinação de carbamato de etila em aguardentes de cana por CG-EM / Determination of ethyl carbamate in sugar cane spirits by GC-MS  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese [...] Abstract in english A simple, specific and sensitive GC-MS procedure with ion m/z 62 was validated for the determination of ethyl carbamate (EC) in spirits. It exhibited linearity over the concentration of 30 to 600 ?g/L with 30 ?g/L limit of quantification. EC was detected in 70 of the 71 samples analyzed with levels [...] from 33 to 2609 ?g/L (mean level = 893 ?g/L). 35% of the samples contained 500 to 1000 ?g/L and 23% contained 150 to 500 and 1000 to 1500 ?g/L. No significant correlation was found between EC and the levels of copper, pH and alcohol content of the samples.

Renata Adriana, Labanca; Maria Beatriz Abreu, Glória; Robson José de Cássia Franco, Afonso.

1860-18-01

360

Residential pesticide use during pregnancy among a cohort of urban minority women.  

Science.gov (United States)

Residential pesticide use is widespread in the United States. However, data are limited specific to use among minority populations. Nor are data available on the extent of pesticide exposure resulting from residential use during pregnancy. We have gathered questionnaire data on pesticide use in the home during pregnancy from 316 African-American and Dominican women residing in northern Manhattan and the South Bronx. Additionally, 72 women underwent personal air monitoring for 48 hr during their third trimester of pregnancy to determine exposure levels to 21 pesticides (19 insecticides and 2 fungicides). Of the women questioned, 266 of 314 (85%) reported that pest control measures were used in the home during pregnancy; 111 of 314 (35%) reported that their homes were sprayed by an exterminator, and of those, 45% said the spraying was done more than once per month. Most (>or= 90%) of the pesticide was used for cockroach control. Use of pest control measures increased significantly with the level of housing disrepair reported. Of the women monitored, all (100%) had detectable levels of three insecticides: the organophosphates diazinon (range, 2.0-6,010 ng/m3) and chlorpyrifos (range, 0.7-193 ng/m3) and the carbamate propoxur (range, 3.8-1,380 ng/m3), as well as the fungicide o-phenylphenol (range, 5.7-743 ng/m3). We also frequently detected the following four insecticides (47-83% of samples) but at lower concentrations: the pyrethroid trans-permethrin, piperonyl butoxide (an indicator of exposure to pyrethrins), and the organochlorines 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane and chlordane. Thirty percent of the women had detectable levels of all eight pesticides. Exposures were generally higher among African Americans than among Dominicans. We detected other pesticides in pesticide use among minority women in this cohort. Diazinon exposures for some women may have exceeded health-based levels, and our findings support recent federal action to phase out residential use of this insecticide. PMID:12003754

Whyatt, Robin M; Camann, David E; Kinney, Patrick L; Reyes, Andria; Ramirez, Judy; Dietrich, Jessica; Diaz, Diurka; Holmes, Darrell; Perera, Frederica P

2002-05-01

361

Use of dispersive liquid-liquid microextraction for the determination of carbamates in juice samples by sweeping-micellar electrokinetic chromatography.  

Science.gov (United States)

Dispersive liquid-liquid microextraction (DLLME) has been proposed for the extraction and preconcentration of 12 carbamate pesticides in juice samples, followed by their determination by micellar electrokinetic chromatography with diode-array detection. To improve sensitivity, an on-capillary sample concentration method based on sweeping has been developed. Also, separations were performed in an extended light path fused-silica capillary; the separation buffer consisted of 100 mM borate and 50 mM SDS (pH 9.0) with 5% acetonitrile. Samples were introduced by hydrodynamic injection, dissolved in the separation buffer, but free of micelles. Several parameters of the DLLME procedure (such as type and volume of extraction and dispersive solvents, pH, salt addition, and extraction time) were optimized. Recoveries obtained for fortified juice samples (banana, pineapple, and tomato) at three different concentration levels, ranged from 78% to 105%, with relative standard deviations lower than 9%. The limits of detection ranged from 1 to 7 ?g l(-1). Moreover, the method is fast, simple, and environmentally friendly. PMID:21279629

Moreno-González, David; Gámiz-Gracia, Laura; García-Campaña, Ana M; Bosque-Sendra, Juan M

2011-05-01

362

Gene transcription in Daphnia magna: effects of acute exposure to a carbamate insecticide and an acetanilide herbicide  

DEFF Research Database (Denmark)

Daphnia magna is a key invertebrate in the freshwater environment and is used widely as a model in ecotoxicological measurements and risk assessment. Understanding the genomic responses of D. magna to chemical challenges will be of value to regulatory authorities worldwide. Here we exposed D. magna to the insecticide methomyl and the herbicide propanil to compare phenotypic effects with changes in mRNA expression levels. Both pesticides are found in drainage ditches and surface water bodies standing adjacent to crops. Methomyl, a carbamate insecticide widely used in agriculture, inhibits acetylcholinesterase, a key enzyme in nerve transmission. Propanil, an acetanilide herbicide, is used to control grass and broad-leaf weeds. The phenotypic effects of single doses of each chemical were evaluated using a standard immobilisation assay. Immobilisation was linked to global mRNA expression levels using the previously estimated 48h-EC(1)s, followed by hybridization to a cDNA microarray with more than 13,000 redundant cDNA clones representing >5000 unique genes. Following exposure to methomyl and propanil, differential expression was found for 624 and 551 cDNAs, respectively (one-way ANOVA with Bonferroni correction, P

Pereira, Joana Luísa; Hill, Christopher J

2010-01-01

363

Pesticides (Environmental Health Student Portal)  

Science.gov (United States)

... Lab (Johns Hopkins University Ecohealth) - An introduction to pesticides, their use by farmers, and their impact on crops, soil quality, beneficial organisms, ecosystems, and our health. Enviro- ...

364

Enantioselective domino reaction of CO2, amines and allyl chlorides under iridium catalysis: formation of allyl carbamates.  

Science.gov (United States)

The enantioselective domino reaction between CO2 (1 atm), amines and linear allyl chlorides in the presence of an iridium complex, DABCO and toluene at 15 °C was realized, which gave branched allyl carbamates in acceptable to high yields with up to excellent regioselectivity (99/1) and 94% ee. This is the first example of the synthesis of chiral allyl carbamates through catalytic domino reactions using CO2. PMID:24652315

Zhang, Min; Zhao, Xiaoming; Zheng, Shengcai

2014-05-01

365

Mitotic chromosome loss induced by methyl benzimidazole-2-yl-carbamate as a rapid mapping method in Saccharomyces cerevisiae.  

OpenAIRE

Mitotic chromosome loss induced by methyl benzimidazole-2-yl-carbamate has been utilized as a rapid and simple method for assigning genes to individual chromosomes in Saccharomyces cerevisiae. This technique relied on the segregation of heterozygous markers in a diploid strain after methyl benzimidazole-2-yl-carbamate treatment due to loss of whole chromosomes. Correlations between the expression of an unmapped gene and that of a previously mapped recessive marker indicated chromosomal linkag...

Wood, J. S.

1982-01-01

366

Concerning Selectivity in the Oxidation of Peptides by Dioxiranes. Further Insight into the Effect of Carbamate Protecting Groups  

OpenAIRE

Using methyl(trifluoromethyl)dioxirane (TFDO), the oxidation of some tripeptide esters protected at the N-terminus with carbamate or amide groups could be achieved efficiently under mild conditions with no loss of configuration at the chiral centers. Expanding on preliminary investigations, it is found that, while peptides protected with amide groups (PG = Ac-, Tfa-, Piv-) undergo exclusive hydroxylation at the side chain, their analogues bearing a carbamate group (PG = Cbz-, Moc-, Boc-, TcBo...

Annese, Cosimo; D’accolti, Lucia; Zotti, Marta; Fusco, Caterina; Toniolo, Claudio; Williard, Paul G.; Curci, Ruggero

2010-01-01

367

Reusable fiber optic immunofluorosensor for rapid detection of pesticides  

Science.gov (United States)

Quartz fibers coated with acetylcholinesterase (AChE) or antibody (Ab) are used as biosensors utilizing total reflectance fluorescence for the rapid detection of pesticides. The enzyme biosensor was constructed by immobilizing fluorescein isothiocyanate (FITC)-tagged eel electric organ AChE on quartz fibers. The fluorescent signal was generated by hydrolysis of acetylcholine (ACh) that is present in the perfusate. Organophosphate (OP) and carbamate anticholinesterase (AntiChE) insecticides inhibited AChE and reduced the fluorescent quenching resulting from AChE hydrolysis. A parathion biosensor was constructed by immobilizing casein-parathion on the quartz fibers, that bound rabbit antiparathion antibody. The optical signal was generated by perfusing the fibers with fluorescein-labeled goat antirabbit IgG. Free parathion inhibited the binding of antiparathion Abs and reduced the optical signal and provided the basis for detection of parathion. Another immunosensor developed detected the herbicide PursuitR by utilizing the reversible binding of a fluorescein-Pursuit derivative to antiPursuit Abs immobilized on the fiber. Unlabeled Pursuit competed effectively and displaced the bound fluorescent compound in a dose-dependent manner. The sensor discriminated effectively between Pursuit-like and structurally unrelated herbicides. The immunosensor offers the advantage of continuous monitoring, ease of operation, speed of detection, low cost, stability, specificity, matrix transparency, and reusability.

Anis, Nabil A.; Valdes, James J.; Thompson, Roy G.; Menking, Darrell E.; Wong, Rosie B.; Eldefrawi, Mohyee E.

1993-05-01

368

49 CFR 172.101 - Purpose and use of hazardous materials table.  

Science.gov (United States)

...L220 LACamphor, synthetic4.1UN2717III4...Detonators, etcCarbamate pesticides, liquid, flammable, toxic...60 LB40Carbamate pesticides, liquid, toxic6.1...220 LA40Carbamate pesticides, liquid, toxic,...

2010-10-01

369

Combined use of biomarkers and in situ bioassays in Daphnia magna to monitor environmental hazards of pesticides in the field.  

Science.gov (United States)

The aim of this investigation was to evaluate toxicity effects of pesticides in aquatic invertebrates using in situ bioassays with the local species, Daphnia magna. Investigations were carried out in the Delta del Ebro (northeast Spain) during the main growing season of rice (May-August). Measures of energy consumption (i.e., algal grazing) and of specific biochemical responses (biomarkers) were conducted in individuals transplanted at four stations, including a clean site upstream of the affected area and the three main channels that collect and drain the water from the rice fields into the sea. Seventeen pesticides were analyzed in water by on-line solid-phase extraction-liquid chromatography-tandem mass spectrometry. The results obtained indicated high levels of pesticides in water, with peak values of 487 microg/L for bentazone, 8 microg/L for methyl-4-chlorophenoxyacetic acid, 5 microg/L for propanil, 0.8 microg/L for molinate, and 0.7 microg/L for fenitrothion. Measured biological responses denoted severe effects on grazing rates; a strong inhibition of cholinesterases and carboxylesterases, which are specific biomarkers of organophosphorous and carbamate pesticides; and altered patterns of the antioxidant enzyme catalase and the phase II metabolizing enzyme glutathione S-transferase. Correlation analysis with pesticide residue levels converted to toxic units relative to its acute 48-h median lethal concentration of D. magna indicated significant and negative coefficients between the dominant pesticide residues and the observed biological response, thus denoting a clear cause-and-effect relationship. The results emphasize the importance of considering specific (biomarkers) as well as more generalized and ecologically related (grazing) in situ responses to identify and evaluate biological effects of environmental contaminants in the field. PMID:17713226

Barata, Carlos; Damasio, Joana; López, Miguel Angel; Kuster, Marina; López de Alda, María; Barceló, Damià; Riva, Mari Carmen; Raldúa, Demetrio

2007-02-01

370

Tag: pesticides | EurActiv  

SCPinfonet

... Study: Regulatory hurdles hinder use of green pesticides - 08 October 2008 - News The development of biological pest control agents is being held back by shortcomings in the current European regulatory system for pesticides, argues a UK study, which describes biopesticides as \\

371

Quality control of pesticide products  

International Nuclear Information System (INIS)

In light of an established need for more efficient analytical procedures, this publication, which documents the findings of an IAEA coordinated research project (CRP) on “Quality Control of Pesticide Products”, simplifies the existing protocol for pesticide analysis while simultaneously upholding existing standards of quality. This publication includes both a report on the development work done in the CRP and a training manual for use by pesticide analysis laboratories. Based on peer reviewed and internationally recognized methods published by the Association of Analytical Communities (AOAC) and the Collaborative International Pesticides Analytical Council (CIPAC), this report provides laboratories with versatile tools to enhance the analysis of pesticide chemicals and to extend the scope of available analytical repertoires. Adoption of the proposed analytical methodologies promises to reduce laboratories’ use of solvents and the time spent on reconfiguration and set-up of analytical equipment

372

Screening level assessment of agricultural pesticides as a pressure factor on European waters  

Science.gov (United States)

Currently about 400 chemical substances are reported in use as agricultural pesticides in Europe. However, little knowledge is available about their actual use patterns, emission rates, and consequently expected concentrations in the environment. In this contribution, we use a simple screening model for the evaluation of pesticide concentrations in soil and water, and we apply it to a number of pesticides, for which some monitored values of concentration are available and used for comparison with computed concentrations. The model relies on practically attainable information such as reported pesticide usage data, land cover, and pan-european soil organic carbon content, runoff rates and temperature-dependent degradation rates. After validating the model, we apply it to compute environmental risk indicators that aim at depicting the cumulative effect of pesticides in Europe. These indicators are in essence weighted sums of concentrations of the different chemicals, where weights are ratios of threshold concentrations such as LC50 or NOEC. The model implies simple and easy-to-track computations, and only exploits widely available information on pesticide emissions and properties. Indicators can be used for the assessment of pesticides in Europe for a generic year. A comparison between different years is discussed, yielding indications on the current trends in pesticide contamination at the continental scale. This type of analysis helps identifying pressure factors in agricultural catchments, and their spatial and temporal trends, and may support the identification of priority hazardous substances for river basin management planning within the Water Framework Directive.

Pistocchi, A.

2009-04-01

373

VizieR Online Data Catalog: Rotational transitions of Methyl carbamate (Groner+, 2007)  

Science.gov (United States)

The rotational-torsional spectrum of the syn conformer of methyl carbamate [CH3OC(:O)NH2], an isomer of the essential amino acid glycine [NH2CH2C(:O)OH], has been recorded at room temperature in the spectral region from 79 to 371GHz. Methyl carbamate possesses a methyl group internal rotor, which gives rise to A and E torsional substates, and associated splittings in the rotational spectrum. Almost 6000 new rotational transitions arising from the vibrational ground state have been assigned, about half of them belonging to the E torsional substate. The Fast Scan Submillimeter-wave Spectroscopic Technique (FASSST) spectrometer at the Ohio State University was used for the present measurements (2 data files).

Groner, P.; Winnewisser, M.; Medvedev, I. R.; de, F. C. Lucia; Herbst, E.; Sastry, K. V. L. N.

2008-11-01

374

Hydrogen-bonding patterns in two aroylthio­carbamates and two aroylimidothio­carbonates  

OpenAIRE

In O-ethyl N-benzoyl­thio­carbamate, C10H11NO2S, the mol­ecules are linked into sheets by a combination of two-centre N—H?O and C—H?S hydrogen bonds and a three-centre C—H?(O,S) hydrogen bond. A combination of two-centre N—H?O and C—H?O hydrogen bonds links the mol­ecules of O-ethyl N-(4-methyl­benzoyl)thio­carbamate, C11H13NO2S, into chains of rings, which are linked into sheets by an aromatic ?–? stacking inter­action. In O,S-diethyl N-(4-methyl­benzoyl)imido...

Insuasty, Henry; Castro, Edison; Sa?nchez, Edison; Cobo, Justo; Glidewell, Christopher

2010-01-01

375

Sprinkler Irrigation-Pesticide Best Management Systems  

OpenAIRE

The relative reduction in potential groundwater contamination due to pesticides at several sites in Utah was determined by comparing alternative irrigation system designs, water management practices, and pesticides. Alternative sprinkler irrigation distribution coefficients were used to estimate irrigation application depths. The movement of pesticides through soils following sprinkler irrigations was simulated with a one-dimensional model. Pesticide contamination of groundwater can be reduce...

Ranjha, A. Y.; Peralta, R. C.; Hill, R. W.; Requena, A. M.; Deer, H. M.; Ehteshami, M.

1991-01-01

376

Enantioselective Hydroformylation of N-Vinyl Carboxamides, Allyl Carbamates and Allyl Ethers Using Chiral Diazaphospholane Ligands  

OpenAIRE

Rhodium complexes of diazaphospholane ligands catalyze the asymmetric hydroformylation of N-vinyl carboxamides, allyl ethers and allyl carbamates; products include 1,2- and 1,3-amino aldehydes and 1,3-alkoxy aldehydes. Using glass pressure bottles, short reaction times (generally less than 6 hours), and low catalyst loading (commonly 0.5 mol %), 20 substrates are successfully converted to chiral aldehydes with useful regioselectivity and high enantioselectivity (up to 99% ee). Chiral Roche al...

Mcdonald, Richard I.; Wong, Gene W.; Neupane, Ram P.; Stahl, Shannon S.; Landis, Clark R.

2010-01-01

377

Hydrogels for Osteochondral Repair Based on Photo-crosslinkable Carbamate Dendrimers  

OpenAIRE

First generation, photo-crosslinkable dendrimers consisting of natural metabolites (i.e. succinic acid, glycerol, and ?-alanine) and non-immunogenic poly(ethylene glycol) (PEG) were synthesized divergently in high yields using ester and carbamate forming reactions. Aqueous solutions of these dendrimers were photo-crosslinked with an eosin-based photo-initiator to afford hydrogels. The hydrogels displayed a range of mechanical properties based on their structure, generation size, and concentr...

Degoricija, Lovorka; Bansal, Prashant N.; So?ntjens, Serge H. M.; Joshi, Neel; Takahashi, Masaya; Snyder, Brian; Grinstaff, Mark W.

2008-01-01

378

Isotope exchange study of bis(diethyl dithio carbamate) cobalt(II) complex  

International Nuclear Information System (INIS)

Isotopic exchange behaviour of bis (diethyl dithio carbamate) cobalt(II) complex is studied at 20degC and 30degC varying the concentrations of both the metal ion and the comnplex. The results show the complex is labile in the kinetic sense and the temperature has a significant effect on the rate of the reaction. The increases in concentration of the metal ion and the complex also increases the reaction rate. (author)

379

Modeling the vibrational spectrum of 4,4'-diphenylmethane-bis(methyl)carbamate  

International Nuclear Information System (INIS)

We present results of ab initio calculations of the structure and vibrational IR spectrum for 4,4'-diphenylmethane-bis(methyl)carbamate (DPMC). Calculations were carried out in the HF/6-311G approximation with subsequent force-field scaling. The calculated characteristics of the vibrational spectrum of DPMC show satisfactory agreement with experimental values, which permits them to be used in spectral and structural analysis. (authors)

380

Modeling the vibrational spectrum of 4,4'-diphenylmethane- bis(methyl)carbamate  

Science.gov (United States)

We present results of ab initio calculations of the structure and vibrational IR spectrum for 4,4'-diphenylmethane-bis(methyl)carbamate (DPMC). Calculations were carried out in the HF/6-311G approximation with subsequent force-field scaling. The calculated characteristics of the vibrational spectrum of DPMC show satisfactory agreement with experimental values, which permits them to be used in spectral and structural analysis

Shundalau, M. B.; Pitsevich, G. A.; Ksenofontov, M. A.; Umreiko, D. S.

2010-07-01

381

tert-Butyl N-(4-methyl-2-pyrid­yl)­carbamate  

OpenAIRE

The crystal structure of the title compound, C11H16N2O2, contains two crystallographically independent molecules forming dimers by pairs of intermolecular N—H...N hydrogen bonds. The two molecules are related by a pseudo-twofold axis. The dihedral angle between the pyridine ring and the carbamate plane differs in the two molecules [12.1?(3) and 3.5?(3)°].

Pierre Koch; Dieter Schollmeyer; Stefan Laufer

2008-01-01

382

New Ultra Small Iron-Oxide Nanoparticles with Titanium-Carbamate Coating: Preparation and Magnetic Properties  

OpenAIRE

This work deals with the preparation and chemical characterization of new Ultra-Small Iron-Oxide Superparamagnetic Nanoparticles (USPIONs) functionalized with Titanium-carbamate. The synthesis was performed starting from oleate-coated and 2-pyrrolidone-coated USPIONs having a maghemite ( -Fe2O3) and magnetite (Fe3O4) crystalline core, respectively. Zero-field-cooled (ZFC) and field-cooled (FC) magnetic susceptibility curves as well as the magnetization behavior as a function of te...

Domenici V.; Dolci S.; Pampaloni G.; Jaglicic Z.

2012-01-01

383

Isotope exchange study of bis(diethyl dithio carbamate) cadmium(II) complex  

International Nuclear Information System (INIS)

Isotope exchange behaviour of bis(diethyl dithio carbamate) cadmium(II) complex was studied at 25 deg C and 35 deg C varying the concentrations of both metal ion and the complex. The results show that the complex is kinetically labile and the concentration has a significant effect on the rate of the reaction. Increase in temperature also affects the rate of exchange. (author)

384

Synthesis of (-)-(S,S)-clemastine by invertive N --> C aryl migration in a lithiated carbamate.  

Science.gov (United States)

The first enantioselective synthesis of the antihistamine agent clemastine, as its (S,S)-stereoisomer, has been achieved by ether formation between a proline-derived chloroethylpyrrolidine and an enantiomerically enriched tertiary alcohol. The tertiary alcohol was formed from the carbamate derivative of alpha-methyl-p-chlorobenzyl alcohol by invertive aryl migration on lithiation. The (S,S)-stereochemistry of the product confirms the invertive nature of the rearrangement. PMID:20405879

Fournier, Anne M; Brown, Robert A; Farnaby, William; Miyatake-Ondozabal, Hideki; Clayden, Jonathan

2010-05-21

385

Solubility improvement of an anthelmintic benzimidazole carbamate by association with dendrimers  

OpenAIRE

The improvement of aqueous solubility of methyl (5-[propylthio]-1H-benzimidazol-2-yl) carbamate, albendazole (ABZ) using polyamidoamine (PAMAM) dendrimers as solubility enhancers was investigated. Full generation PAMAM dendrimers with amine terminal groups, (G3), with hydroxyl terminal groups (G3OH) and half generation PAMAM dendrimers with carboxylate terminal groups (G2.5 and G3.5), were chosen for this study. The nature of dendrimer-ABZ association was investigated by UV absorption, fluore...

Ferna?ndez, L.; Sigal, E.; Otero, L.; Silber, J. J.; Santo, M.

2011-01-01

386

Structure-Activity Studies on Nematicidal Activity of Dialkyl Carbamates and Thiocarbamates  

OpenAIRE

In laboratory tests, 129 dialkyl carbamates of types ROC(O)NHR', RSC(O)NHR', and ROC(S)NHR' were tested in a screening bioassay against Panagrellus redivivus. The 10 most active were lethal at concentrations from 5 ppm down to ca. 1 ppm. Eight of these (the only ones active below 2.5 ppm) were thiolcarbamates (RSC(O)NHR'). Decyl N-methyhhiolcarbamate was also lethal to Meloidogyne incognita at approximately 1 ppm in direct contact tests.

Kochansky, Jan; Feldmesser, Julius

1989-01-01

387

Genetic effects of methyl benzimidazole-2-yl-carbamate on Saccharomyces cerevisiae.  

OpenAIRE

The genetic effects of the mitotic inhibitor methyl benzimidazole-2-yl-carbamate (MBC) have been studied in Saccharomyces cerevisiae. MBC had little or no effect on the frequency of mutation. In some experiments MBC caused an increase in the frequency of mitotic recombination; however, this effect was small and not reproducible. The primary genetic effect of MBC was to induce mitotic chromosome loss at a high frequency. Chromosome loss occurred at equal frequencies for all chromosomes tested ...

Wood, J. S.

1982-01-01

388

Synthesis of dimethyl carbonate from methyl carbamate and methanol over lanthanum compounds  

Energy Technology Data Exchange (ETDEWEB)

Various lanthanum compounds were used as the catalyst for the synthesis of dimethyl carbonate (DMC) from methyl carbamate and methanol. Among them, La(NO{sub 3}){sub 3} presented the best catalytic performance with the DMC yield of 53.7% under suitable reaction conditions. Based on the results of X-ray diffraction, Fourier transform infrared spectroscopy and element analysis, a possible reaction mechanism over lanthanum nitrate was proposed for this reaction. (author)

Wang, Dengfeng; Zhang, Xuelan; Gao, Yangyan [State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan, 030001 (China); Graduate university of Chinese, Academy of Sciences, Beijing, 100049 (China); Xiao, Fukui; Wei, Wei; Sun, Yuhan [State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan, 030001 (China)

2010-09-15

389

Ab Initio Investigation of Hydrogen Bonding by Carbamates. Complexes including N-methyl methylcarbamate, N-phenyl methylcarbamate, dimethyl ether, and methyl acetate  

OpenAIRE

Hydrogen bonds of the type N-H··O which occur in interactions between N-methyl methyl carbamate or N-phenyl methylearbamate and (i) a second carbamate, (ii) an ester, and (iii) an ether are studied by ab initio methods using a minimal MINI-1 basis set. Of the three, the ether forms the strongest complex with a carbamate. Replacement of the methyl group bonded to the proton-donating N of the carbamate by a phenyl group leads to a somewhat stronger H-bond in all cases. The electron density pa...

Remko, M.; Scheiner, Steve

1988-01-01

390

Monitoring pesticide residues in greenhouse tomato by combining acetonitrile-based extraction with dispersive liquid-liquid microextraction followed by gas-chromatography-mass spectrometry.  

Science.gov (United States)

A multiclass and multiresidue method for pesticide analysis in tomato was validated. Extraction and pre-concentration of the pesticide residues from acetonitrile extracts was performed by using dispersive liquid-liquid microextraction (DLLME) technique, followed by gas chromatography-mass detection. DLLME was performed using carbon tetrachloride as extractive solvent and acetonitrile extract as dispersive solvent, in order to increase enrichment factor of the extraction procedure. Validation parameters indicated the suitability of the method for routine analyses of thirty pesticides in a large number of samples. In general, pesticide recoveries ranged between 70% and 110% and repeatability ranged between 1% and 20%. The proposed method was applied to the monitoring of pesticides in tomatoes grown during winter in greenhouses. Among the compounds considered in this work, cyprodinil was found in tomato at concentrations of 0.33mg/kg, other pesticides like azoxystrobin, fenhexanid, tolyfluanid, ?-cyhalothrin and trifloxystrobin were also detected, but, not quantified. PMID:22953826

Melo, Armindo; Cunha, Sara C; Mansilha, Catarina; Aguiar, Ana; Pinho, Olívia; Ferreira, Isabel M P L V O

2012-12-01

391

Differential responses of eight cyanobacterial and green algal species, to carbamate insecticides.  

Science.gov (United States)

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." PMID:16677910

Ma, Jianyi; Lu, Ninghai; Qin, Wendi; Xu, Ruifu; Wang, Yunbing; Chen, Xining

2006-02-01

392

77 FR 23713 - Pesticides; Final Guidance on Material Safety Data Sheets as Pesticide Labeling; Request for...  

Science.gov (United States)

...labels for pesticides registered...the Material Safety Data Sheet...Safety and Health Administration...part of the pesticide's labeling...accompany a pesticide product without...Occupational Safety and Health...

2012-04-20

393

Pesticide use and application: an Indian scenario.  

Science.gov (United States)

Agricultural development continues to remain the most important objective of Indian planning and policy. In the process of development of agriculture, pesticides have become an important tool as a plant protection agent for boosting food production. Further, pesticides play a significant role by keeping many dreadful diseases. However, exposure to pesticides both occupationally and environmentally causes a range of human health problems. It has been observed that the pesticides exposures are increasingly linked to immune suppression, hormone disruption, diminished intelligence, reproductive abnormalities and cancer. Currently, India is the largest producer of pesticides in Asia and ranks twelfth in the world for the use of pesticides. A vast majority of the population in India is engaged in agriculture and is therefore exposed to the pesticides used in agriculture. Although Indian average consumption of pesticide is far lower than many other developed economies, the problem of pesticide residue is very high in India. Pesticide residue in several crops has also affected the export of agricultural commodities in the last few years. In this context, pesticide safety, regulation of pesticide use, proper application technologies, and integrated pest management are some of the key strategies for minimizing human exposure to pesticides. There is a dearth of studies related to these issues in India. Therefore, the thrust of this paper was to review the technology of application of pesticides in India and recommend future strategies for the rational use of pesticides and minimizing the problems related to health and environment. PMID:19081675

Abhilash, P C; Singh, Nandita

2009-06-15

394

Pesticide use and application: An Indian scenario  

International Nuclear Information System (INIS)

Agricultural development continues to remain the most important objective of Indian planning and policy. In the process of development of agriculture, pesticides have become an important tool as a plant protection agent for boosting food production. Further, pesticides play a significant role by keeping many dreadful diseases. However, exposure to pesticides both occupationally and environmentally causes a range of human health problems. It has been observed that the pesticides exposures are increasingly linked to immune suppression, hormone disruption, diminished intelligence, reproductive abnormalities and cancer. Currently, India is the largest producer of pesticides in Asia and ranks twelfth in the world for the use of pesticides. A vast majority of the population in India is engaged in agriculture and is therefore exposed to the pesticides used in agriculture. Although Indian average consumption of pesticide is far lower than many other developed economies, the problem of pesticide residue is very high in India. Pesticide residue in several crops has also affected the export of agricultural commodities in the last few years. In this context, pesticide safety, regulation of pesticide use, proper application technologies, and integrated pest management are some of the key strategies for minimizing human exposure to pesticides. There is a dearth of studies related to these issues in India. Therefore, the thrust of this paper was to review the technology of applicati was to review the technology of application of pesticides in India and recommend future strategies for the rational use of pesticides and minimizing the problems related to health and environment.

395

Analytical methods for detecting pesticide switches with evolution of pesticide resistance  

OpenAIRE

After a pest develops resistance to a pesticide, switching between different unrelated pesticides is a common management option, but this raises the following questions: (1) What is the optimal frequency of pesticide use? (2) How do the frequencies of pesticide applications affect the evolution of pesticide resistance? (3) How can the time when the pest population reaches the economic injury level (EIL) be estimated and (4) how can the most ef?cient frequency of pesticide applications be de...

Liang, Juhua; Tang, Sanyi; Nieto, Juan J.; Cheke, Robert A.

2013-01-01

396

Movement of pesticides from the site of application  

International Nuclear Information System (INIS)

Important among the data needed to reduce the environmental risks potentially associated with pesticide use is a clear understanding of environmental processes. Much information has been accumulated and this is discussed with special reference to the research being carried out by scientists of the Agricultural Research Service of the United States Department of Agriculture at Beltsville. Physical and chemical properties are important in predicting the environmental fate of a pesticide. Routes of dissipation from the site of application will be influenced by the agricultural system and the method of application. Causes of loss include runoff and a three year study showed the extent of herbicide runoff to the Wye River Estuary. Potential contamination of groundwater by leaching has been recognized as a problem in certain cases and its extent and causes are being extensively studied. Volatilization may be a significant source of loss. Two important factors are the vapour pressure of the pesticide and the nature of the surface. Pesticide volatilization was measured using specially designed sampling equipment. Losses from dry soil surfaces were much smaller than the rapid losses from moist surfaces. Losses were predictable in terms of the vapour pressure of the compound and its interaction with surfaces. Atmospheric movement is important in the transport of pesticides. They may be redeposited on the Earth's surface by a number of mechanisms including rainfall, fog and snowechanisms including rainfall, fog and snow or be adsorbed on particulate matter. A specially constructed sampler was used to collect the liquid and vapour phases of fog. Pesticides, their alteration products, plasticizers, flame retardants, industrial chemicals and combustion products were found in fog samples collected in Maryland and California. Distribution between liquid and vapour phases was not in accordance with Henry's Law and experiments are in progress to measure Henry's Law constants to validate these observations. 26 refs, 2 figs, 3 tabs

397

Radiation induced pesticidal microbes  

Energy Technology Data Exchange (ETDEWEB)

To isolate pesticidal microbes against plant pathogenic fungi, 4 strains of bacteria(K1. K3, K4, YS1) were isolated from mushroom compost and hot spring. K4, K1, K3, YS1 strain showed wide antifungal spectrum and high antifungal activities against 12 kinds of fungi. Specific proteins and the specific transcribed genes were found from the YS1 and its radiation-induced mutants. And knock-out mutants of antifungal activity were derived by transposon mutagenesis. From these knock-out mutants, the antifungal activity related genes and its modification by gamma-ray radiation are going to be studied. These results suggested that radiation could be an useful tool for the induction of functional mutants.

Kim, Ki Yup; Lee, Y. K.; Kim, J. S.; Kim, J. K.; Lee, S. J.; Lim, D. S

2001-01-01

398

Radiation induced pesticidal microbes  

International Nuclear Information System (INIS)

To isolate pesticidal microbes against plant pathogenic fungi, 4 strains of bacteria(K1. K3, K4, YS1) were isolated from mushroom compost and hot spring. K4, K1, K3, YS1 strain showed wide antifungal spectrum and high antifungal activities against 12 kinds of fungi. Specific proteins and the specific transcribed genes were found from the YS1 and its radiation-induced mutants. And knock-out mutants of antifungal activity were derived by transposon mutagenesis. From these knock-out mutants, the antifungal activity related genes and its modification by gamma-ray radiation are going to be studied. These results suggested that radiation could be an useful tool for the induction of functional mutants

399

Protonation switching to the least-basic heteroatom of carbamate through cationic hydrogen bonding promotes the formation of isocyanate cations.  

Science.gov (United States)

We found that phenethylcarbamates that bear ortho-salicylate as an ether group (carbamoyl salicylates) dramatically accelerate O?C bond dissociation in strong acid to facilitate generation of isocyanate cation (N-protonated isocyanates), which undergo subsequent intramolecular aromatic electrophilic cyclization to give dihydroisoquinolones. To generate isocyanate cations from carbamates in acidic media as electrophiles for aromatic substitution, protonation at the ether oxygen, the least basic heteroatom, is essential to promote C?O bond cleavage. However, the carbonyl oxygen of carbamates, the most basic site, is protonated exclusively in strong acids. We found that the protonation site can be shifted to an alternative basic atom by linking methyl salicylate to the ether oxygen of carbamate. The methyl ester oxygen ortho to the phenolic (ether) oxygen of salicylate is as basic as the carbamate carbonyl oxygen, and we found that monoprotonation at the methyl ester oxygen in strong acid resulted in the formation of an intramolecular cationic hydrogen bond (>C?O(+) ?H???Omethyl ester oxygen of the salicylate and the carbonyl oxygen of the carbamate afforded a rather stable dication, which did not readily undergo C?O bond dissociation. This is an unprecedented and unknown case in which the monocation has greater reactivity than the dication. PMID:24920101

Kurouchi, Hiroaki; Sumita, Akinari; Otani, Yuko; Ohwada, Tomohiko

2014-07-01

400

Pesticides in the propolis at São Saulo State, Brazil / Pesticidas na própolis do Estado de São Paulo, Brasil  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese A crescente procura pela própolis tem ocasionado aumento em sua produção. Entretanto, uma agricultura cada vez mais dependente de pesticidas representa preocupação com relação à contaminação ambiental, além das abelhas e seus produtos. Neste sentido, a proposta do presente trabalho foi avaliar a pre [...] sença de pesticidas (organoclorados, organofosforados, piretroides, carbamatos, herbicidas, fungicidas e acaricidas) em amostras de própolis do Estado de São Paulo. Apicultores de diversas localidades do Estado forneceram amostras de própolis (50). Estas foram coletadas, armazenadas em sacos plásticos atóxicos e mantidas em freezer até as análises. Os possíveis resíduos de pesticidas foram analisados por cromatografia gasosa. Não foi observada a presença dos pesticidas analisados nas amostras. Neste caso, a própolis analisada no Estado de São Paulo não apresentou contaminação por pesticidas. Abstract in english The increasing demand for propolis has caused a raise in its production. However, an increasingly pesticide-dependent agriculture is a great concern with regard to bees, their produce and environmental contamination. Current analysis evaluates the presence of pesticides (organochlorines, organophosp [...] hates, pyrethroids, carbamates, herbicides, fungicides and acaricides) in samples of propolis from the state of São Paulo, Brazil. Beekeepers from several localities in the state provided samples of propolis (50), which were collected, stored in non-toxic plastic bags and maintained in a freezer for analyses. Possible pesticide residues were examined by gas chromatography method but no pesticide residues were detected in the examined propolis samples. Propolis analyzed in the state of São Paulo did not show any pesticide contamination.

Ricardo de Oliveira, Orsi; Lidia Maria Ruv Carelli, Barreto; Silvia Maria Alves, Gomes; Samir Moura, Kadri.

2012-12-01

401

Pesticide movement and water management  

OpenAIRE

Agricultural chemicals are essential components of agricultural production systems in the United states. Pesticides control weeds, insects, and have had an important role in increasing agricultural productivity in the last 50 years, despite diminishing crop land acreage. The benefits of chemicals use options in agriculture must be balanced against potential contamination of surface water and ground water resources. This study shows the effect of water management practices on pesticide movemen...

Ehteshami, M.; Peralta, R. C.

1989-01-01

402

Canadian pesticide air sampling campaign  

Energy Technology Data Exchange (ETDEWEB)

Although pesticides are widely used in Canada, little is known about the presence, distribution, and fate of currently used pesticides (CUPs) in the Canadian atmosphere. This paper provided details of a campaign conducted in 2003 to provide information on air and precipitation levels of CUPs. The objective of the campaign was to create pesticide emission inventories and to identify important pesticide issues related to environmental fate, exposure, and risk assessment in order to develop effective pesticide policies. A Canadian atmospheric network for currently used pesticides was established, which was then followed by an intensive field study in the Canadian prairies. Air samples were collected weekly using high volume PS-1 samplers with polyurethane foam (PUF) XAD sandwiches and glass fibre filters. Precipitation samples were collected each month using MIC samplers equipped with XAD columns. Passive air samplers were deployed at many of the sites for periods of 1 to 3 months. Results of the study showed relatively high concentrations of endosulfan at all sites. High levels of chloropyrifos, malathion, and carbofurans were also detected from air samples. High concentrations of lindane were also observed. Alachlor, metochlor, and trifluralin concentrations were detected in most Ontario and Quebec air and rainfall samples. Eleven target pesticides were detected from air samples during the prairie study. High concentrations of triallate were observed, and good correlations between air concentration trends and dry deposition trends were seen for triallate, 2,4-D, MCPA, dicamba, and bromoxynil. Results of the campaign are now being modelled using a simplified gridded pesticide emission and residue model. 4 refs., 7 figs.

Yao, Y.; Harner, T.; Blanchard, P.; Li, Y.F.; Aulagnier, F. [Environment Canada, Gatineau, PQ (Canada). Meteorological Service of Canada; Tuduri, L. [Laboratoire de Physico Toxicochimie des Systemes Naturels, Talence (France). Equipe Perigourdine de Chimie Appliquee; Waite, D.; Belzer, W. [Environment Canada, Ottawa, ON (Canada). Environmental Conservation Branch; Murphy, C. [Environment Canada, Ottawa, ON (Canada). Environmental Protection Service

2005-07-01

403

40 CFR 170.230 - Pesticide safety training for handlers.  

Science.gov (United States)

...2010-07-01 2010-07-01 false Pesticide safety training for handlers. 170...Pesticide Handlers § 170.230 Pesticide safety training for handlers. ...certification or licensing is pesticide safety training that includes all...

2010-07-01

404

Disposable screen-printed electrode coupled with recombinant Drosophila melanogaster acetylcholinesterase and multiwalled carbon nanotubes for rapid detection of pesticides.  

Science.gov (United States)

Recombinant Drosophila melanogaster acetylcholinesterase (R-DmAChE), multiwalled carbon nanotubes (MWCNTs), and Prussian blue have been combined for development of a three-electrode biosensor with more rapid responses and higher stability than in our previous study. A new disposable screen-printed electrode (SPE) was developed for rapid detection of organophosphate and carbamate pesticides. After optimization, 10 microg MWCNT and 5 microL enzyme immobilization solution consisting of 0.2% glutaraldehyde, 0.1% Nafion, 0.2% bovine serum albumin, 0.1 g/L MWCNT, and 1.5 mU R-DmAChE were fixed on each of the R-DmAChE/MWCNT SPEs. The LOD of this biosensor was 0.5 microg/L for pesticide standards of dichlorvos (DDV) and carbofuran. The performance of this biosensor was tested for vegetable and water samples at various spiked levels, and good stability and sensitivity were found. The obtained recoveries were from 82.6 to 110.5% for DDV at levels of 0.5-5 microg/L and 73.4 to 118.4% for carbofuran at 1-10 microg/L in lake and sea water samples, demonstrating that the proposed approach is an alternative means for rapid detection of pesticide residues and contaminants in food safety and environmental monitoring. PMID:21391508

Tang, Zhuzhao; Chen, Haode; Song, Shiping; Fan, Chunhai; Zhang, Dabing; Wu, Aibo

2011-01-01

405

A bi-enzymatic whole cell conductometric biosensor for heavy metal ions and pesticides detection in water samples.  

Science.gov (United States)

A conductometric biosensor using immobilised Chlorella vulgaris microalgae as bioreceptors was used as a bi-enzymatic biosensor. Algae were immobilised inside bovine serum albumin membranes reticulated with glutaraldehyde vapours deposited on interdigitated conductometric electrodes. Local conductivity variations caused by algae alkaline phosphatase and acetylcholinesterase activities could be detected. These two enzymes are known to be inhibited by distinct families of toxic compounds: heavy metals for alkaline phosphatase, carbamates and organophosphorous (OP) pesticides for acetylcholinesterase. The bi-enzymatic biosensors were tested to study the influence of heavy metal ions and pesticides on the corresponding enzyme. It has finally appeared that these biosensors are quite sensitive to Cd2+ and Zn2+ (limits of detection (LOD) = 10 ppb for a 30 min long exposure) while Pb2+ gives no significant inhibition as this ion seems to adsorb on albumin preferably. For pesticides, first experiments showed that paraoxon-methyl inhibits C. vulgaris AChE contrary to parathion-methyl and carbofuran. Biosensors were then exposed to different mixtures (Cd2+/Zn2+, Cd2+/paraoxon-methyl) but no synergetic or antagonist effect could be observed. A good repeatability could be achieve with biosensors since the relative standard deviation did not exceed 8% while response time was 5-7 min. A comparison between inhibition levels obtained with biosensors (after a 30 min long exposure) and bioassays (after a 240 min long exposure) has finally shown a similar LOD for both Cd and Zn (LOD = 10 ppb). PMID:16023954

Chouteau, Celine; Dzyadevych, Sergei; Durrieu, Claude; Chovelon, Jean-Marc

2005-08-15

406

Cholinesterase activities and sensitivity to pesticides in different tissues of silver European eel, Anguilla anguilla.  

Science.gov (United States)

Cholinesterase (ChE) activities were characterized in silver European eel, Anguilla anguilla, grown in the brackish lagoon of Comacchio (Italy). All specimens were harvested at the "lavoriero", a traditional eel trapping weir that captures eels while leaving internal waters at the onset of reproductive migration. To our knowledge, no investigation on ChE was reported in silver eels. Therefore a first characterization of enzyme activity in muscle, brain, liver and plasma of silver eel was carried out, in the presence of different substrates, selective inhibitors, and four pesticides representative of the carbamate and organophosphate classes. Brain and white skeletal muscle showed similar ChE activities, 5- and 10-fold higher than those detected in liver and plasma, respectively. Km values of 0.31 and 0.30 mM, and Vmax values of 40.28 and 35.47 nmol min(-1) mg protein(-1) were obtained in brain and muscle ChE, respectively. Acetycholinesterase was the predominant ChE form in all tissues, as concluded by comparing the effects of BW 284c51, iso-OMPA and eserine. ChE activities in brain and muscle were significantly inhibited by in vitro treatment with pesticides, with the following order of potency: carbofuran>carbaryl>chlorpyrifos?diazinon. PMID:21777695

Valbonesi, P; Brunelli, F; Mattioli, M; Rossi, T; Fabbri, E

2011-11-01

407

Pesticides' influence on wine fermentation.  

Science.gov (United States)

Wine quality strongly depends on the grape quality. To obtain high-quality wines, it is necessary to process healthy grapes at the correct ripeness stage and for this reason the farmer has to be especially careful in the prevention of parasite attacks on the grapevine. The most common fungal diseases affecting grape quality are downy and powdery mildew (Plasmopara viticola and Uncinula necator), and gray mold (Botrytis cinerea). On the other hand, the most dangerous insects are the grape moth (Lobesia botrana), vine mealybug (Planococcus ficus), and the citrus mealybug (Planococcus citri). Farmers fight grape diseases and insects applying pesticides that can be found at harvest time on grapes. The persistence of pesticides depends on the chemical characteristic of the active ingredients as well as on photodegradation, thermodegradation, codistillation, and enzymatic degradation. The pesticide residues on grapes can be transferred to the must and this can influence the selection and development of yeast strains. Moreover, yeasts can also influence the levels of the pesticides in the wine by reducing or adsorbing them on lees. During the fermentative process, yeasts can cause the disappearance of pesticide residues by degradation or absorption at the end of the fermentation when yeasts are deposited as lees. In this chapter, we reviewed the effect of commonly used herbicides, insecticides, and fungicides on yeasts. We also studied the effect of alcoholic and malolactic fermentation on pesticide residues. PMID:20610173

Caboni, Pierluigi; Cabras, Paolo

2010-01-01

408

Trabalho rural e fatores de risco associados ao regime de uso de agrotóxicos em Minas Gerais, Brasil Rural work and risk factors associated with pesticide use in Minas Gerais, Brazil  

Directory of Open Access Journals (Sweden)

Full Text Available O objetivo deste artigo foi caracterizar o processo do trabalho rural em nove municípios de Minas Gerais, considerando indicadores sócio-demográficos, a estrutura agrária dos estabelecimentos rurais, práticas de trabalho relacionadas ao uso de agrotóxicos e, a intoxicação associada a seu uso. Os dados foram obtidos de uma pesquisa realizada pela Fundação Jorge Duprat Figueiredo, de Segurança e Medicina do Trabalho, que aplicou um questionário a 1.064 trabalhadores rurais, entre os anos de 1991 a 2000. Por meio de uma regressão logística, foram obtidos os fatores de risco associados à intoxicação por agrotóxicos dos grupos organofosforados e carbamatos. Cerca de 50% dos entrevistados se encontravam ao menos moderadamente intoxicados. Os fatores de risco encontrados foram: ter o último contato a menos de duas semanas com agrotóxicos; não usar proteção; ser orientado pelo vendedor; citar organofosforado ou carbamato como agrotóxico principal e trabalhar nos municípios de Teófoli Otoni, Guidoval ou Piraúba. Os resultados apontam para o alto grau de risco de agravos à saúde a que estão sujeitos trabalhadores rurais em contato com agrotóxicos.This paper aimed to characterize the rural work process in nine counties in Minas Gerais State, considering socio-demographic indicators, the land tenure structure of farm operations, and work practices related to pesticide use and poisoning Data were obtained through the Jorge Duprat Figueiredo Foundation for Workers' Safety and Occupational Medicine, which applied a questionnaire to 1,064 rural workers from 1991 to 2000. Through a logistic regression, risk factors associated with pesticide poisoning were obtained for the carbamate and organophosphate groups. Some 50% of interviewees displayed at least moderate pesticide toxicity. Risk factors for pesticide poisoning were: last contact with pesticides less than two weeks before the blood cholinesterase test; no use of personal protective equipment by workers applying pesticides; having received instructions from the pesticide salesperson; report of carbamates/organophosphates as the main pesticides used; and working in the counties of Teófoli Otoni, Guidoval, or Piraúba. The results emphasize the high level of health risk associated with pesticide use among these rural workers.

Wagner Soares

2003-08-01

409

Applicability of ELISA-based Determination of Pesticides for Groundwater Quality Monitoring  

Science.gov (United States)

The principals and procedures of ELISA (Enzyme-linked Immunosorbent Assay)-based determination of pesticides (Fenitrothion) in environmental samples were reviewed, and the applicability of the ELISA method for groundwater quality monitoring were validated through the experimental tracer tests in soil columns and the field test in Okinoerabu Island. The test results showed that the ELISA method could be useful not only for screening but also for quantitative analysis of pesticides. In the experimental tracer tests in soil columns, the retardation of pesticides leaching compared with conservative tracers were observed. In the field test, the contamination of the pesticide was detected in groundwater samples in Okinoerabu Island, even though the targeted pesticide was considered to be applied to the upland field 4 months ago. In order to investigate the transport and fate of pesticides in groundwater taking into account retardation from the field to groundwater table and the residue in groundwater, continuous observations of pesticides in groundwater are in a strong need, and the ELISA method is applicable to the long-term quality groundwater monitoring.

Tsuchihara, Takeo; Yoshimoto, Shuhei; Ishida, Satoshi; Imaizumi, Masayuki

410

Pesticide volatilization from soil and plant surfaces: Measurements at different scales versus model predictions  

Energy Technology Data Exchange (ETDEWEB)

Simulation of pesticide volatilization from plant and soil surfaces as an integral component of pesticide fate models is of utmost importance, especially as part of the PEC (predicted environmental concentrations) models used in the registration procedures for pesticides. Experimentally determined volatilization rates at different scales were compared to model predictions to improve recent approaches included in European registration models. To assess the influence of crucial factors affecting volatilization under well-defined conditions, a laboratory chamber was set-up and validated. Aerodynamic conditions were adjusted to fulfill the requirements of the German guideline on assessing pesticide volatilization for registration purposes. At the semi-field scale, volatilization rates were determined in a wind-tunnel study after soil surface application of pesticides to gleyic cambisol. The following descending order of cumulative volatilization was observed: chlorpyrifos > parathion-methyl > terbuthylazine > fenpropimorph. Parameterization of the models PEARL (pesticide emission assessment at regional and local scales) and PELMO (pesticide leaching model) was performed to mirror the experimental boundary conditions. (orig.)

Wolters, A.

2003-07-01

411

Long-term relationships among pesticide applications, mobility, and soil erosion in a vineyard watershed.  

Science.gov (United States)

Agricultural pesticide use has increased worldwide during the last several decades, but the long-term fate, storage, and transfer dynamics of pesticides in a changing environment are poorly understood. Many pesticides have been progressively banned, but in numerous cases, these molecules are stable and may persist in soils, sediments, and ice. Many studies have addressed the question of their possible remobilization as a result of global change. In this article, we present a retro-observation approach based on lake sediment records to monitor micropollutants and to evaluate the long-term succession and diffuse transfer of herbicides, fungicides, and insecticide treatments in a vineyard catchment in France. The sediment allows for a reliable reconstruction of past pesticide use through time, validated by the historical introduction, use, and banning of these organic and inorganic pesticides in local vineyards. Our results also revealed how changes in these practices affect storage conditions and, consequently, the pesticides' transfer dynamics. For example, the use of postemergence herbicides (glyphosate), which induce an increase in soil erosion, led to a release of a banned remnant pesticide (dichlorodiphenyltrichloroethane, DDT), which had been previously stored in vineyard soil, back into the environment. Management strategies of ecotoxicological risk would be well served by recognition of the diversity of compounds stored in various environmental sinks, such as agriculture soil, and their capability to become sources when environmental conditions change. PMID:25313074

Sabatier, Pierre; Poulenard, Jérôme; Fanget, Bernard; Reyss, Jean-Louis; Develle, Anne-Lise; Wilhelm, Bruno; Ployon, Estelle; Pignol, Cécile; Naffrechoux, Emmanuel; Dorioz, Jean-Marcel; Montuelle, Bernard; Arnaud, Fabien

2014-11-01

412

75 FR 60452 - Notice of Filing of Several Pesticide Petitions for Residues of Pesticide Chemicals in or on...  

Science.gov (United States)

...Several Pesticide Petitions for Residues of Pesticide Chemicals in or on Various...establishment of regulations for residues of pesticide chemicals in or on various...regulations in 40 CFR part 180 for residues of pesticide chemicals in or on...

2010-09-30

413

78 FR 1798 - Receipt of a Pesticide Petition Filed for Residues of Pesticide Chemicals in or on Various...  

Science.gov (United States)

...Pesticide Petition Filed for Residues of Pesticide Chemicals in or on Various...modification of regulations for residues of pesticide chemicals in or on various...regulations in 40 CFR part 180 for residues of pesticide chemicals in or on...

2013-01-09

414

76 FR 3885 - Notice of Receipt of a Pesticide Petition Filed for Residues of Pesticide Chemicals in or on...  

Science.gov (United States)

...Pesticide Petition Filed for Residues of Pesticide Chemicals in or on Various...modification of regulations for residues of pesticide chemicals in or on various...CFR part 174 or part 180 for residues of pesticide chemicals in or on...

2011-01-21

415

76 FR 33183 - Receipt of a Pesticide Petition Filed for Residues of Pesticide Chemicals in or on Various...  

Science.gov (United States)

...Pesticide Petition Filed for Residues of Pesticide Chemicals in or on Various...modification of regulations for residues of pesticide chemicals in or on various...CFR part 174 or part 180 for residues of pesticide chemicals in or on...

2011-06-08

416

78 FR 6274 - Withdrawal of Pesticide Petitions for Residues of Pesticide Chemicals in or on Various Commodities  

Science.gov (United States)

...of Pesticide Petitions for Residues of Pesticide Chemicals in or on Various...modification of regulations for residues of pesticide chemicals in or on various...regulations in 40 CFR part 180 for residues of pesticide chemicals in or on...

2013-01-30

417

76 FR 2110 - Notice of Receipt of a Pesticide Petition Filed for Residues of Pesticide Chemicals in or on...  

Science.gov (United States)

...Pesticide Petition Filed for Residues of Pesticide Chemicals in or on Various...modification of regulations for residues of pesticide chemicals in or on various...CFR part 174 or part 180 for residues of pesticide chemicals in or on...

2011-01-12

418

78 FR 70906 - Receipt of a Pesticide Petition Filed for Residues of Pesticide Chemicals in or on Various...  

Science.gov (United States)

...Pesticide Petition Filed for Residues of Pesticide Chemicals in or on Various...modification of regulations for residues of pesticide chemicals in or on various...regulations in 40 CFR part 180 for residues of pesticide chemicals in or on...

2013-11-27

419

76 FR 20667 - Notice of Withdrawal of Pesticide Petitions for Residues of Pesticide Chemicals in or on Various...  

Science.gov (United States)

...of Pesticide Petitions for Residues of Pesticide Chemicals in or on Various...modification of regulations for residues of pesticide chemicals in or on various...regulations in 40 CFR part 180 for residues of pesticide chemicals in or on...

2011-04-13

420

Presence of organophosphorus pesticide oxygen analogs in air samples  

Science.gov (United States)

A number of recent toxicity studies have highlighted the increased potency of oxygen analogs (oxons) of several organophosphorus (OP) pesticides. These findings were a major concern after environmental oxons were identified in environmental samples from air and surfaces following agricultural spray applications in California and Washington State. This paper reports on the validity of oxygen analog measurements in air samples for the OP pesticide, chlorpyrifos. Controlled environmental and laboratory experiments were used to examine artificial formation of chlorpyrifos-oxon using OSHA Versatile Sampling (OVS) tubes as recommended by NIOSH method 5600. Additionally, we compared expected chlorpyrifos-oxon attributable to artificial transformation to observed chlorpyrifos-oxon in field samples from a 2008 Washington State Department of Health air monitoring study using non-parametric statistical methods. The amount of artificially transformed oxon was then modeled to determine the amount of oxon present in the environment. Toxicity equivalency factors (TEFs) for chlorpyrifos-oxon were used to calculate chlorpyrifos-equivalent air concentrations. The results demonstrate that the NIOSH-recommended sampling matrix (OVS tubes with XAD-2 resin) was found to artificially transform up to 30% of chlorpyrifos to chlorpyrifos-oxon, with higher percentages at lower concentrations (pesticide concentration when using XAD-2 resin matrices for occupational or residential sampling. Alternative methods that can accurately measure both OP pesticides and their oxygen analogs should be used for air sampling, and a toxicity equivalent factor approach should be used to determine potential health risks from exposures.

Armstrong, Jenna L.; Fenske, Richard A.; Yost, Michael G.; Galvin, Kit; Tchong-French, Maria; Yu, Jianbo

2013-02-01

421

PestLCI 2.0: a second generation model for estimating emissions of pesticides from arable land in LCA  

DEFF Research Database (Denmark)

The spatial dependency of pesticide emissions to air, surface water and groundwater is illustrated and quantified using PestLCI 2.0, an updated and expanded version of PestLCI 1.0.PestLCI is a model capable of estimating pesticide emissions to air, surface water and groundwater for use in life cycle inventory (LCI) modelling of field applications. After calculating the primary distribution of pesticides between crop and soil, specific modules calculate the pesticide’s fate, thus determining the pesticide emission pattern for the application. PestLCI 2.0 was developed to overcome the limitations of the first model version, replacement of fate calculation equations and introducing new modules for macropore flow and effects of tillage. The accompanying pesticide database was expanded, the meteorological and soil databases were extended to include a range of European climatic zones and soil profiles. Environmental emissions calculated by PestLCI 2.0 were compared to results from the risk assessment models SWASH (surface water emissions), FOCUSPEARL (groundwater via matrix leaching) and MACRO (groundwater including macropore flow, only one scenario available) to partially validate the updated model. A case study was carried out to demonstrate the spatial variation of pesticide emission patterns due to dependency on meteorological and soil conditions.Compared to PestLCI 1.0, PestLCI 2.0 calculated lower emissions to surface water and higher emissions to groundwater. Both changes were expected due to new pesticide fate calculation approaches and the inclusion of macropore flow. Differences between the SWASH and FOCUSPEARL and PestLCI 2.0 emission estimates were generally lower than 2 orders of magnitude, with PestLCI generally calculating lower emissions. This is attributed to the LCA approach to quantify average cases, contrasting with the worst-case risk assessment approach inherent to risk assessment. Compared to MACRO, the PestLCI 2.0 estimates for emissions to groundwater were higher, suggesting that PestLCI 2.0 estimates of fractions leached to groundwater may be slightly conservative as a consequence of the chosen macropore modelling approach. The case study showed that the distribution of pesticide emissions between environmental compartments strongly depends on local climate and soil characteristics.PestLCI 2.0 is partly validated in this paper. Judging from the validation data and case study, PestLCI 2.0 is a pesticide emission model in acceptable accordance with both state-of-the-art pesticide risk assessment models. The case study underlines that the common pesticide emission estimation practice in LCI may lead to misestimating the toxicity impacts of pesticide use in LCA.

Dijkman, Teunis Johannes; Birkved, Morten

2012-01-01

422

Estrogenic and esterase-inhibiting potency in rainwater in relation to pesticide concentrations, sampling season and location  

International Nuclear Information System (INIS)

Estrogenic potency of rainwater correlated well with organochlorine concentrations, but could not be attributed to specific pesticides. - In a year-round monitoring program (1998), pesticide composition and toxic potency of the mix of pollutants present in rainwater were measured. The goal of the study was to relate atmospheric deposition of toxic potency and pesticide composition to each other and to sampling period and local agricultural activity. Rainwater was collected in 26 consecutive periods of 14 days in a background location (BACK) and in two locations representative for different agricultural practices, i.e. intensive greenhouse horticulture (HORT) and flower bulb culture (BULB). Samples were chemically analyzed for carbamate (CARB), organophosphate (OP) and organochlorine (OC) pesticides and metabolites. Esterase inhibiting potency of rainwater extracts was measured in a specially developed bio-assay with honeybee esterases and was expressed as an equivalent concentration of the model inhibitor dichlorvos. Estrogenic potency of the extracts was measured in the ER-CALUX reporter gene assay and was expressed as an equivalent concentration of estradiol. Multivariate principal component analysis (PCA) techniques proved to be valuable tools to analyze the numerous pesticide concentrations in relation to toxic potency, sampling location, and sampling season. Pesticide composition in rainwater depended much more on sampling season than on sampling location, but dig season than on sampling location, but differences between SPRING and SUMMER were mainly attributed to local differences in agricultural practice. On average, the esterase inhibiting potency exceeded the max