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Validation and use of a fast sample preparation method and liquid chromatography-tandem mass spectrometry in analysis of ultra-trace levels of 98 organophosphorus pesticide and carbamate residues in a total diet study involving diversified food types.  

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This paper reports a comprehensive sensitive multi-residue liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for detection, identification and quantitation of 73 pesticides and their related products, a total of 98 analytes, belonging to organophosphorus pesticides (OPPs) and carbamates, in foods. The proposed method makes use of a modified QuEChERS (quick, easy, cheap, effective, rigged, and safe) procedure that combines isolation of the pesticides and sample clean-up in a single step. Analysis is performed by liquid chromatography-electrospray ionization-tandem mass spectrometry operated in the multiple reaction monitoring (MRM) mode, acquiring two specific precursor-product ion transitions per target compound. Two main fragment ions for each pesticide were obtained to achieve the identification according to the SANCO guidelines 10684/2009. The method was validated with various food samples, including edible oil, meat, egg, cheese, chocolate, coffee, rice, tree nuts, citric fruits, vegetables, etc. No significant matrix effect was observed for tested pesticides, therefore, matrix-matched calibration was not necessary. Calibration curves were linear and covered from 1 to 20 microg L(-1) for all compounds studied. The average recoveries, measured at 10 microg kg(-1), were in the range 70-120% for all of the compounds tested with relative standard deviations below 20%, while a value of 10 microg kg(-1) has been established as the method limit of quantitation (MLOQ) for all target analytes. Similar trueness and precision results were also obtained for spiking at 200 microg kg(-1). Expanded uncertainty values were in the range 21-27% while the HorRat ratios were below 1. The method has been successfully applied to the analysis of 700 food samples in the course of a baseline monitoring study of OPPs and carbamates. PMID:20557892

Chung, Stephen W C; Chan, Benny T P

2010-07-16

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Effect of soil properties on the persistence of carbamate pesticides.  

Science.gov (United States)

Persistence of six carbamate pesticides (oxamyl, I; carbaryl, II; phorate, III; phosphomidon, IV; carbofuran, V and methomyl, VI) on ten different soils of Aligarh district was investigated in the laboratory incubated conditions under different moisture levels; temperature; pesticide concentration; acidic, neutral and alkaline pH; FYM (farm yield manure) and nitrogen concentration. The process of degradation followed first order kinetics. The rate of degradation of all the six carbamate pesticides in studied soils was found to increase with rise in temperature, moisture content, amount of FYM or N and decrease with increasing pesticidal concentration. The degradation was more rapid in alkaline medium than neutral or acidic medium. The values of activation energies (Ea) showed that the degradation of pesticides in soils is due to microbial activity and probably enzymatic. The degradation of pesticides was in the order I > VI > V > IV > II > III. The degradation of pesticides in different soils was in the order S1 > S2 > S3 > S4 > S5 > S6 > S7 > S8, > S9 > S10. PMID:21117417

Bansal, O P

2009-10-01

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Piezoelectric Biosensors for Organophosphate and Carbamate Pesticides: A Review  

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Full Text Available Due to the great amount of pesticides currently being used, there is an increased interest for developing biosensors for their detection. Among all the physical transducers, piezoelectric systems have emerged as the most attractive due to their simplicity, low instrumentation costs, possibility for real-time and label-free detection and generally high sensitivity. This paper presents an overview of biosensors based on the quartz crystal microbalance, which have been reported in the literature for organophosphate and carbamate pesticide analysis.

Giovanna Marrazza

2014-09-01

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Influence of clay minerals on the hydrolysis of carbamate pesticides.  

Science.gov (United States)

Using batch experiments, we investigated the influence of clay minerals (montmorillonite, beidellite, illite, and vermiculite) on the hydrolysis of five carbamate pesticides: carbosulfan, carbofuran, aldicarb, pirimicarb, and chlorpropham. Compared to the other minerals, montmorillonite had the strongest influence on the hydrolysis of these carbamates. Montmorillonite enhanced the hydrolysis of carbosulfan and aldicarb. In contrast, the hydrolysis of chlorpropham was inhibited by montmorillonite, probably because of its strong adsorption on montmorillonite. The hydrolysis of pirimicarb was not affected by montmorillonite. The presence of organic substances, phosphate, and fluoride in suspensions decreased the catalytic activity of montmorillonite. Surface acidity of montmorillonite and/or formation of surface chelates are probably the key factors of surface catalysis in the case of the hydrolysis of carbosulfan. PMID:11414023

Wei, J; Furrer, G; Kaufmann, S; Schulin, R

2001-06-01

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Sensitivity of Acetylcholinesterases from Aphelenchus avenae to Organophosphorous and Carbamate Pesticides  

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The sensitivities of acetylcholinesterases (ACHE) from the nematode Aphelenchus avenae and the house fly Musca domestica to various pesticides were compared using a colorimetric assay. ACHE from A. avenae were generally less sensitive than ACHE from M. domestica to inhibition by organophosphorous and carbamate pesticides. Carbamates were somewhat more inhibiting than organophosphorous pesticides to nematode ACHE. In vivo tests with concentrations of various pesticides up to 500 ppm in sand ca...

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

1987-01-01

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Induction of tibial dyschondroplasia by carbamate and thiocarbamate pesticides.  

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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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ANTICHOLINESTERASE ACTION OF PESTICIDAL CARBAMATES IN THE CENTRAL NERVOUS SYSTEM OF POISONED FISHES  

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In the report, kinetic enzyme methods and statistical analyses are used to define the relationship between brain acetycholinesterase inhibition and near-median kills in replicate groups of marine fish in the laboratory by five carbamate pesticides....

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

Science.gov (United States)

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 alpha4beta4 nicotinic receptors is fenoxycarb > EPTC > carbaryl, bendiocarb > propoxur > aldicarb with IC50 values ranging from 3 microM for fenoxycarb to 165 microM 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 microM for bendiocarb to 17 microM for carbaryl and > mM for EPTC and fenoxycarb. The alpha4beta2, alpha3beta4, and alpha3beta2 nicotinic acetylcholine receptors are inhibited by fenoxycarb, EPTC, and carbaryl with potency orders similar to that for alpha4beta4 receptors. Comparing the potencies of inhibition of the distinct subtypes of nicotinic acetylcholine receptors shows that the alpha3beta2 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 alpha and beta subunit properties. It is concluded that carbamate pesticides affect different subtypes of neuronal nicotinic receptors independently of acetylcholinesterase inhibition. This implicates 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. PMID:14644616

Smulders, Chantal J G M; Bueters, Tjerk J H; Van Kleef, Regina G D M; Vijverberg, Henk P M

2003-12-01

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

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

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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...

13

USE OF STRUCTURE-REACTIVITY RELATIONSHIPS TO ESTIMATE HYDROLYTIC PERSISTENCE OF CARBAMATE PESTICIDES  

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Linear free energy relationships are given for use in estimating alkaline hydrolysis of carbamate pesticides in water as applied to environmental conditions. Plots of the second-order alkaline hydrolysis rate constants versus pKa of the resulting alcohol are given for N, N-dimeth...

14

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

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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...

15

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

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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. ...

THOMMANDRU RAVEENDRANATH BAB; SARVAREDDY RAJASEKHAR REDDY; PUCHAKAYALA SUJANA

2014-01-01

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Kuwait's total diet study: dietary intake of organochlorine, carbamate, benzimidazole and phenylurea pesticide residues.  

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The State of Kuwait in cooperation with the U.S. Food and Drug Administration (FDA) conducted a Total Diet Study (TDS) to estimate intakes of pesticide residues by the population. The levels of organochlorine (OC) pesticides, carbamates, benzimidazoles, and phenylureas in the TDS core list are reported here. The TDS core list was established through a national food consumption survey. All food items (140 for the Kuwaiti adult) were prepared as eaten and analyzed for the pesticides mentioned above. The FDA's multiresidue methods in Volume I of the Pesticide Analytical Manual were used in gas, liquid, and gel permeation chromatographic analyses. Only vegetable and fruit samples contained pesticide residues (mg/kg), including the carbamates 1-naphthol (1.4) and 3H-carbofuran (0.94) in carrots; the OC pesticide vinclozolin (0.47), 3H-carbofuran (0.66), and fenuron (0.6) in kiwi fruit; the OC pesticide procymidone (0.32) and carbendazim (0.5) in grapes; 3H-carbofuran (5.0) in apricots; the OC pesticides captan (0.013) and thiabendazole (0.63) in pears; captan (0.035) in plums; and carbendazim (0.4) in mandarin oranges. The levels of 3H-carbofuran found in both apricots and kiwi fruit exceeded the maximum residue limits (MRLs) of the Food and Agriculture Organization/World Health Organization (FAO/WHO) of the United Nations. The daily intakes of pesticides by the different population groups are discussed in light of the FAO/WHO acceptable daily intakes. PMID:10589497

Sawaya, W N; al-Awadhi, F A; Saeed, T; al-Omair, A; Ahmad, N; Husain, A; Khalafawi, S; al-Omirah, H; Dashti, B; al-Amiri, H; al-Saqer, J

1999-01-01

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

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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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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.

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

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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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A highly sensitive, dual-readout assay based on gold nanoparticles for organophosphorus and carbamate pesticides.  

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This report presents a highly sensitive, rhodamine B-covered gold nanoparticle (RB-AuNP) -based assay with dual readouts (colorimetric and fluorometric) for detecting organophosphorus and carbamate pesticides in complex solutions. The detection mechanism is based on the fact that these pesticides can inhibit the activity of acetylcholinesterase (AChE), thus preventing the generation of thiocholine (which turns the RB-AuNP solutions blue and unquenches the fluorescence of RB simultaneously). The color of the RB-AuNP solution remains red and the fluorescence of RB remains quenched. By use of this dual-readout assay, the lowest detectable concentrations for several kinds of pesticides including carbaryl, diazinon, malathion, and phorate were measured to be 0.1, 0.1, 0.3, and 1 ?g/L, respectively, all of which are much lower than the maximum residue limits (MRL) as reported in the European Union pesticides database as well as those from the U.S. Department Agriculture (USDA). This assay allows detection of pesticides in real samples such as agricultural products and river water. The results in detecting pesticide residues collected from food samples via this method agree well with those from high-performance liquid chromatography (HPLC). This simple assay is therefore suitable for sensing pesticides in complex samples, especially in combination with other portable platforms. PMID:22475016

Liu, Dingbin; Chen, Wenwen; Wei, Jinhua; Li, Xuebing; Wang, Zhuo; Jiang, Xingyu

2012-05-01

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

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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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Simple, specific analysis of organophosphorus and carbamate pesticides in sediments using column extraction and gas chromatography  

Science.gov (United States)

A simple, specific procedure was developed for the analysis of organophosphorus and carbamate pesticides in sediment. The wet soil was mixed with anhydrous sodium sulfate to bind water and the residues were column extracted in acetone:methylene chloride (1:l,v/v). Coextracted water was removed by additional sodium sulfate packed below the sample mixture. The eluate was concentrated and analyzed directly by capillary gas chromatography using phosphorus and nitrogen specific detectors. Recoveries averaged 93 % for sediments extracted shortly after spiking, but decreased significantly as the samples aged.

Belisle, A.A.; Swineford, D.M.

1988-01-01

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Adsorption Kinetics of Carbamate Pesticide in Rice Field Soil  

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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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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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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-...

27

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...

28

Determination of carbamate and organophosphorus pesticides in vegetable samples and the efficiency of gamma-radiation in their removal.  

Science.gov (United States)

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 levels above the maximum residue levels determined by the World Health Organisation. Three carbamates (carbaryl, carbofuran, and pirimicarb) and six organophosphates (phenthoate, diazinon, parathion, dimethoate, phosphamidon, and pirimiphos-methyl) were detected in eggplant samples; the highest carbofuran level detected was 1.86?mg/kg, while phenthoate was detected at 0.311?mg/kg. Gamma radiation decreased pesticide levels proportionately with increasing radiation doses. Diazinon, chlorpyrifos, and phosphamidon were reduced by 40-48%, 35-43%, and 30-45%, respectively, when a radiation strength of 0.5?kGy was utilized. However, when the radiation dose was increased to 1.0?kGy, the levels of the pesticides were reduced to 85-90%, 80-91%, and 90-95%, respectively. In summary, our study revealed that pesticide residues are present at high amounts in vegetable samples and that gamma radiation at 1.0?kGy can remove 80-95% of some pesticides. PMID:24711991

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

2014-01-01

29

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...

30

Amperometric biosensing of carbamate and organophosphate pesticides utilizing screen-printed tyrosinase-modified electrodes.  

Science.gov (United States)

A tyrosinase (Tyr) screen-printed biosensor based on the electroreduction of enzymatically generated quinoid products was electrochemically characterized and optimized for determination of carbamates and organophosphorus pesticides. A composite electrode prepared by screen-printing a cobalt (II) phthalocyanine (CoPc) modified cellulose-graphite composite on a polycarbonate support was employed as electrochemical transducer. The Tyr biosensor was prepared by immobilization of enzyme on the composite electrode surface by cross-linking with glutaraldehyde and bovine serum albumin. Parameters affecting the biosensor response such as response time, enzyme loading, concentration and pH of the buffer solution were optimized utilizing catechol as substrate. The maximum response for o-quinone enzymatically generated was obtained after 2 min of reaction. A good reproducibility and high operational stability were found for Tyr biosensor (60 units) at 50 mM phosphate buffer, pH 6.50. Under these conditions, the useful lifetime of biosensor was 10 days. After 15 days, the biosensor could be used with 20% of the initial value. Inhibition studies on the o-quinone steady-state current (at -0.20 V versus Ag/AgCl) were performed to investigate the inhibition kinetics of the pesticides in the enzymatic activity of mushroom tyrosinase. The results shown that the methyl parathion and carbofuran can lead to competitive inhibition process of the enzyme, while diazinon and carbaryl act as mixed inhibitors. Linear relationships were found for methyl parathion (6-100 ppb), diazinon (19-50 ppb), carbofuran (5-90 ppb) and carbaryl (10-50 ppb). Analysis of natural river water samples spiked with 30 ppb of each pesticide showed recoveries between 92.50% and 98.50% and relative standard deviations of 2%. PMID:17631099

de Albuquerque, Yaico D Tanimoto; Ferreira, Lucas Franco

2007-07-23

31

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

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

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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

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A fast, simple and green method for the extraction of carbamate pesticides from rice by microwave assisted steam extraction coupled with solid phase extraction.  

Science.gov (United States)

This paper presented a fast, simple and green sample pretreatment method for the extraction of 8 carbamate pesticides in rice. The carbamate pesticides were extracted by microwave assisted water steam extraction method, and the extract obtained was immediately applied on a C18 solid phase extraction cartridge for clean-up and concentration. The eluate containing target compounds was finally analysed by high performance liquid chromatography with mass spectrometry. The parameters affecting extraction efficiency were investigated and optimised. The limits of detection ranging from 1.1 to 4.2ngg(-1) were obtained. The recoveries of 8 carbamate pesticides ranged from 66% to 117% at three spiked levels, and the inter- and intra-day relative standard deviation values were less than 9.1%. Compared with traditional methods, the proposed method cost less extraction time and organic solvent. PMID:24054230

Song, Weitao; Zhang, Yiqun; Li, Guijie; Chen, Haiyan; Wang, Hui; Zhao, Qi; He, Dong; Zhao, Chun; Ding, Lan

2014-01-15

34

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

35

A noncompetitive, sequential mechanism for inhibition of rat alpha4beta2 neuronal nicotinic acetylcholine receptors by carbamate pesticides.  

Science.gov (United States)

The mechanism by which carbamate pesticides inhibit rat alpha4beta2 nicotinic acetylcholine (ACh) receptors (nAChRs) expressed in Xenopus laevis oocytes has been investigated using the two-electrode voltage clamp technique. Carbaryl, S-ethyl N,N-dipropylthiocarbamate (EPTC), and fenoxycarb inhibit ACh-induced ion currents in a concentration-dependent way. EPTC and fenoxycarb inhibit ion currents induced by 1 mM ACh with 3-fold to 5-fold higher potency than ion currents induced by 1 microM ACh. The potency of carbaryl appears to be independent of ACh concentration. Fenoxycarb displaces (3)H-epibatidine bound to alpha4beta2 (nAChRs) with a K(i) of 750 microM, which is much higher than the functional IC(50) of 2.3-11 microM. This shows that the inhibition of ion current by the carbamate is a noncompetitive effect. Inhibition by fenoxycarb is independent of the state of the ion channel. The rate of onset of inhibition is enhanced, and the rate of reversal of inhibition is reduced, when the concentration of fenoxycarb is increased. The rate of reversal of inhibition is also reduced when the period of exposure to fenoxycarb is increased. The time- and concentration-dependent inhibition of nAChR-mediated ion current by fenoxycarb is accounted for by a two-step mechanism involving a rapid blocked state and a sequential more stably blocked or desensitized state. PMID:15329441

Smulders, Chantal J G M; Van Kleef, Regina G D M; de Groot, Aart; Gotti, Cecilia; Vijverberg, Henk P M

2004-11-01

36

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 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

37

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

38

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

39

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

40

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.

 
 
 
 
41

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...

42

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

43

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 ...

Spiridon Kintzios; Alexandros Michaelides; Olga Mangana; Georgia Moschopoulou; Kelly Flampouri; Sophie Mavrikou

2008-01-01

44

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

45

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

46

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

47

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.

48

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

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Validation of the PESTLA Model: Evaluation of the Validation Statuses of the Pesticide Leaching Models PRZM-1, LEACHP, GLEAMS and PELMO.  

Science.gov (United States)

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. ...

H. van den Bosch, J. J. T. I. Boesten

1995-01-01

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Validation (in-house and collaboratory) of the quantification method for ethyl carbamate in alcoholic beverages and soy sauce by GC-MS.  

Science.gov (United States)

A method for ethyl carbamate (EC) determination in alcoholic beverages and soy sauce was developed by GC-MS. We adopted the diatomaceous earth solid-phase extraction (SPE) column and elution solvent of ethyl acetate/diethyl ether (5:95 v/v) for sample cleaning. The in-house validation showed the limit of quantification (LOQ) was 5.0 ?g/kg. In the accuracy assay, the total average recovery for was 96.7%. The relative standard deviations (RSDs) were <5%. Subsequently, a collaborative trial was organized for the further validation. The RSDs for repeatability and reproducibility were 1.2-7.8% and 2.3-9.6% respectively. It indicated that the present method performed well in different laboratories. PMID:23993600

Huang, Zhu; Pan, Xiao-Dong; Wu, Ping-Gu; Chen, Qing; Han, Jian-Long; Shen, Xiang-Hong

2013-12-15

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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...

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EXTENSION OF MULTI-RESIDUE METHODOLOGY. I. DETERMINING MULTICLASS PESTICIDE RESIDUES IN SOIL BY GAS CHROMATOGRAPHY. II. DYNAMIC FLUOROGENIC LABELLING DETECTOR FOR CARBAMATES  

Science.gov (United States)

A multi-residue procedure was devised for the extraction, cleanup and determination of forty seven pesticides in fortified soil samples. Most of the compounds were determined by gas chromatography interfaced with either the electron capture or the flame photometric detector. Seve...

53

Simultaneous quantification of carbamate insecticides in human plasma by liquid chromatography/tandem mass spectrometry.  

Science.gov (United States)

Carbofuran (CFN), carbosulfan (CSN) and fenobucarb (FBC) are carbamate pesticides that are widely used in gardening and agriculture for the control of insects. Human poisoning due to occupational or self-poisoning exposures is also reported, so assays are required to quantify the plasma concentration of these insecticides. An LC-MS/MS method was developed and validated for the simultaneous quantification of these three carbamate insecticides in the plasma of patients with acute intentional self-poisoning. Plasma samples were pretreated by acetonitrile for protein precipitation. Chromatography was carried out on a Luna C18(2) analytical column with gradient elution using a mobile phase containing acetonitrile and water with 10mM ammonium acetate. Mass spectrometric analysis was performed by an Applied Biosystems MDS Sciex API 2000 triple quadrupole mass spectrometer coupled with electrospray ionization (ESI) source in the positive ion mode. The total run time was 7 min. The assay was validated over a concentration range from 10 to 1000 ng/ml for CSN and FBC and 20-2000 ng/ml for CFN. The precision and accuracy for both intra- and inter-day determination of all analytes were acceptable (<15%). No significant matrix effect was observed. Stability of compounds was established for short term bench and autosampler storage as well as freeze/thaw cycles. The method was effectively applied to 270 clinical samples from patients with a history of acute intentional carbamate self-poisoning. PMID:21723210

Mostafa, Ahmed; Medley, Gregory; Roberts, Darren M; Mohamed, Mosaad Sayed; Elshanawani, Abdalla A; Roberts, Michael S; Liu, Xin

2011-08-01

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Pesticides  

Science.gov (United States)

... exposure, as well as on the treatment and prevention of pesticide poisoning. Evaluating Chemicals: Is It ... Student Edition Lesson: Arsenic and Lead Scavenger Hunt (357KB) EHP Student Edition ...

55

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

56

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.

57

Method development and validation for the determination of pesticides in green coffee by gas chromatography  

International Nuclear Information System (INIS)

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 acetate cyclohexane (1:1) partitioning. The clean up steps include gel permeation chromatography and mini column chromatography using silica gel. Final determination was carried out by high-resolution gas chromatography with a pulsed split less injection mode and simultaneous detection by ?-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

58

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.

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Method development and validation for the simultaneous determination of organochlorine and organophosphorus pesticides in a complex sediment matrix.  

Science.gov (United States)

The Xochimilco area in the southeastern part of Mexico City has a variety of socioeconomic activities, such as periurban agriculture, which is of great importance in the Mexico City metropolitan area. Pesticides are used extensively, some being legal, mostly chlorpyrifos and malathion, and some illegal, mostly DDT. Sediments are a common sink for pesticides in aquatic systems near agricultural areas, and Xochimilco sediments have a complex composition with high contents of organic matter and clay that are ideal adsorption sites for organochlorine (OC) and organophosphorus (OP) pesticides. Therefore, it is important to have a quick, affordable, and reliable method to determine these pesticides. Conventional methods for the determination of OC and OP pesticides are long, laborious, and costly owing to the high volume of solvents and adsorbents. The present study developed and validated a method for determining 18 OC and five OP pesticides in sediments with high organic and clay contents. In contrast with other methods described in the literature, this method allows isolation of the 23 pesticides with a 12 min microwave-assisted extraction (MAE) and one-step cleanup of pesticides. The method developed is a simpler, time-saving procedure that uses only 3.5 g of dry sediment. The use of MAE eliminates excessive handling and the possible loss of analytes. It was shown that the use of LC-Si cartridges with hexane-ethyl acetate (75+25, v/v) in the cleanup procedure recovered all pesticides with rates between 70 and 120%. The validation parameters demonstrated good performance of the method, with intermediate precision ranging from 7.3 to 17.0%, HorRat indexes all below 0.5, and tests of accuracy with the 23 pesticides at three concentration levels demonstrating recoveries ranging from 74 to 114% and RSDs from 3.3 to 12.7%. PMID:24000760

Alcántara-Concepción, Victor; Cram, Silke; Gibson, Richard; Ponce de León, Claudia; Mazari-Hiriart, Marisa

2013-01-01

60

Mutagenic effects of carbosulfan, a carbamate pesticide.  

Science.gov (United States)

The genotoxic effects of carbosulfan were evaluated using chromosome aberration (CA), bone marrow micronucleus (MN) and sperm abnormality assays in mice. All the three acute doses (1.25, 2.5 and 5mg/kg) of carbosulfan induced significant dose-dependent increase in the frequency of CA (Pcarbosulfan induced >7-fold increase in the frequency of CA, >3.5-fold increase in the frequency of micronucleated PCEs and >4.6-fold increase in the frequency of sperms with abnormal head morphology following intraperitoneal exposure as compared to the untreated controls. The present findings suggest that carbosulfan is a potent genotoxic agent and may be regarded as a potential germ cell mutagen also. PMID:12160893

Giri, Sarbani; Giri, Anirudha; Sharma, Gouri Dutt; Prasad, Surya Bali

2002-08-26

 
 
 
 
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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)

62

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...

63

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

64

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...

65

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

66

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

67

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.

68

Development and validation of a multiresidue method for determination of 82 pesticides in water using GC.  

Science.gov (United States)

Several methods used for the multiresidue analysis of pesticides from the environment and drinking water have been reported. However, most of these reports dealt with a small number of targeted pesticides or some special groups. A method that is simple, faster, and more cost-effective than the environmental protection agency (EPA) method has been developed for the analysis of 82 frequently used pesticides in water samples obtained from Yeongsan and Sumjin rivers, as well as rice fields located in various locations around the two rivers. The samples were extracted by dichloromethane, and the pesticides were analyzed using a GC-electron capture detector (ECD), followed by confirmation with GC-MS. Recoveries were found to be between 82 and 120.1% for most of the tested pesticides, which were in agreement with the standard values dictated by the EPA. The method was potentially applied to 66 water samples for human consumption and 90 water samples from the rice fields and irrigation ditches that were collected from June to September 2007. Oxadiazon, butachlor, and alachlor were detected in some of the river water samples collected in June, iprobenfos (IBP) was detected in samples collected in August, and no pesticide was detected in September. On the other hand, chlorpyrifos-methyl, IBP, hexaconazole, diazinon, oxadiazon, butachlor, and isoprothiolane were detected at relatively high concentrations in 48 rice paddy field water samples collected between June and September 2007. Alachlor in one sample and procymidone in some of the rice paddy field water samples were also detected in trace amounts. The results were consistent with the temporal pattern of pesticide application in Korean rice fields. PMID:19212978

Mamun, Md Iqbal Rouf; Park, Jong Hyouk; Choi, Jeong-Heui; Kim, Hee Kwon; Choi, Woo Jung; Han, Seong-Soo; Hwang, Kyungsup; Jang, Nam-Ik; Assayed, Mohamed Ezzat; El-Dib, Mohamed Anwer; Shin, Ho-Chul; Abd El-Aty, A M; Shim, Jae-Han

2009-02-01

69

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

70

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

71

[Validation study on a rapid multi-residue method for determination of pesticide residues in vegetables and fruits by LC-MS/MS].  

Science.gov (United States)

A validation study was conducted on a rapid multiresidue method for determination of pesticide residues in vegetables and fruits by LC-MS/MS. Pesticide residues in the vegetables or fruits were extracted with acetonitrile in a disposable tube using a homogenizer, followed by salting out with anhydrous magnesium sulfate and sodium chloride in the presence of citrate salts for buffering. The extract was purified with a double-layered cartridge column (graphite carbon black/primary secondary amine silica gel; GCB/PSA). For citrus fruits a purification step with a C18 column was added (this column was connected to the GCB/PSA column). After removal of the solvent, the extract was resolved in methanol/water and analyzed by means of LC-MS/MS. The method was validated according to the method validation guideline of the Ministry of Health, Labour and Welfare of Japan; recovery tests were performed on 8 kinds of vegetables and fruits [cabbage, cucumber, Japanese radish, onion, potato, spinach, Amanatsumikan (a citrus fruit) and apple] by fortification of 161 pesticide residues at the concentrations 0.01 and 0.05 ?g/g (each concentration of pesticide residue was extracted from 2 samples on 5 separate days). The trueness of the method for 127 pesticides in all 8 commodities was 70-120% with satisfactory repeatability and within-run reproducibility. This method is concluded to be applicable for determination of pesticide residues in vegetables and fruits. PMID:23863370

Takatori, Satoshi; Yamamoto, Haruna; Fukui, Naoki; Yamaguchi, Satoko; Kitagawa, Yoko; Kakimoto, You; Osakada, Masakazu; Okihashi, Masahiro; Kajimura, Keiji; Obana, Hirotaka

2013-01-01

72

COMPARATIVE GENOTOXICITY STUDIES OF ETHYL CARBAMATE AND RELATED CHEMICALS: FURTHER SUPPORT FOR VINYL CARBAMATE AS A PROXIMATE CARCINOGENIC METABOLITE  

Science.gov (United States)

In vivo and/or in vitro mammalian cell systems were used to evaluate sister chromatid exchange (SCE) induction and gene mutagenesis effects following exposure to ethyl carbamate (urethane), vinyl carbamate, ethyl N-hydroxycarbamate, and 2-hydroxyethyl carbamate....

73

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.

74

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

75

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

76

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)

77

Diagnosis & Treatment of Poisoning by Pesticides.  

Science.gov (United States)

This report succinctly discusses the steps necessary to diagnose and treat poisoning from pesticides, especially organophosphates, carbamates and chlorinated hydrocarbons. Immediate and continuing steps in the care of poisoning victims are outlined with supportive information on where to locate emergency assistance. (CS)

Environmental Protection Agency, Washington, DC. Office of Pesticide Programs.

78

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  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 ...

Maria Isabel Ribeiro Alves; Nelson Roberto Antoniosi Filho

2010-01-01

79

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.

80

Detection of pesticide by polymeric enzyme electrodes.  

Science.gov (United States)

Screen-printed electrodes (SPEs) containing immobilized acetylcholine esterase (AChE) enzyme were used for the electrochemical determination of organophosphorous (OP) and carbamate pesticides. The extent of AChE deactivation by the pesticide was determined in the presence of acetylcholine (AChCl) substrate. The unique nature of this approach lies in the enzyme immobilization procedure in which AChE was attached to the SPE by in situ bulk polymerization of acrylamide to ensure efficient adherence within the membrane with minimal losses in enzyme activity. Responses were observed for the pesticides Monocrotophos, Malathion, Metasystox and Lannate over the concentration range 0-10 ppb (microg L(-1)). PMID:17328951

Dutta, K; Bhattacharyay, D; Mukherjee, A; Setford, S J; Turner, A P F; Sarkar, P

2008-03-01

 
 
 
 
81

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...

82

Electrochemical study of some insecticides deriving from carbamates in aprotic media  

International Nuclear Information System (INIS)

With the rapid growth of the population, there is an increasing demand for agriculture products and a consequent need of pesticides. It is essential to have an analytical methodology to monitoring them in the environment. The present work reports the electrochemical behavior of three carbamate insecticides, methiocarb, bendiocarb and zectran. In oxidation, the cyclic voltammetry measurements indicated an irreversible electrode process for each insecticide in organic media. The electron transfer stoichiometry was determined; the effects of the concentration and the scan rate on oxidation of these compounds were investigated. There was evidence of an ECE type reaction. The principal oxidation products of the carbamate insecticides were determined in acetonitrile using mass spectrometry analysis. Results of this study will be used to develop an electrochemical method for analyzing these compounds.

83

Treatment rationale for dogs poisoned with aldicarb (carbamate pesticide)  

Scientific Electronic Library Online (English)

Full Text Available SciELO South Africa | Language: English Abstract in english The treatment rationale for dogs poisoned by aldicarb is reviewed from a pharmacological perspective. The illegal use of aldicarb to maliciously poison dogs is a major problem in some parts of the world. In South Africa, it is probably the most common canine poisoning treated by companion animal vet [...] erinarians. Aldicarb poisoning is an emergency and veterinarians need to be able to diagnose it and start with effective treatment immediately to ensure a reasonable prognosis. Successful treatment depends on the timely use of an anti-muscarinic drug (e.g. atropine). Additional supportive treatment options, including fluid therapy, diphenhydramine, benzodiazepines and the prevention of further absorption (activated charcoal) should also be considered. Possible complications after treatment are also briefly discussed.

L F, Arnot; D J H, Veale; J C A, Steyl; J G, Myburgh.

84

Treatment rationale for dogs poisoned with aldicarb (carbamate pesticide).  

Science.gov (United States)

The treatment rationale for dogs poisoned by aldicarb is reviewed from a pharmacological perspective. The illegal use of aldicarb to maliciously poison dogs is a major problem in some parts of the world. In South Africa, it is probably the most common canine poisoning treated by companion animal veterinarians. Aldicarb poisoning is an emergency and veterinarians need to be able to diagnose it and start with effective treatment immediately to ensure a reasonable prognosis. Successful treatment depends on the timely use of an anti-muscarinic drug (e.g. atropine). Additional supportive treatment options, including fluid therapy, diphenhydramine, benzodiazepines and the prevention of further absorption (activated charcoal) should also be considered. Possible complications after treatment are also briefly discussed. PMID:22616438

Arnot, L F; Veale, D J H; Steyl, J C A; Myburgh, J G

2011-12-01

85

Ab Initio Investigations of the Hydrolysis of the Carbamate Bond  

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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

86

[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

87

Quantification of endocrine disruptors and pesticides in water by gas chromatography-tandem mass spectrometry. Method validation using weighted linear regression schemes.  

Science.gov (United States)

A multi-residue methodology based on a solid phase extraction followed by gas chromatography-tandem mass spectrometry was developed for trace analysis of 32 compounds in water matrices, including estrogens and several pesticides from different chemical families, some of them with endocrine disrupting properties. Matrix standard calibration solutions were prepared by adding known amounts of the analytes to a residue-free sample to compensate matrix-induced chromatographic response enhancement observed for certain pesticides. Validation was done mainly according to the International Conference on Harmonisation recommendations, as well as some European and American validation guidelines with specifications for pesticides analysis and/or GC-MS methodology. As the assumption of homoscedasticity was not met for analytical data, weighted least squares linear regression procedure was applied as a simple and effective way to counteract the greater influence of the greater concentrations on the fitted regression line, improving accuracy at the lower end of the calibration curve. The method was considered validated for 31 compounds after consistent evaluation of the key analytical parameters: specificity, linearity, limit of detection and quantification, range, precision, accuracy, extraction efficiency, stability and robustness. PMID:20553685

Mansilha, C; Melo, A; Rebelo, H; Ferreira, I M P L V O; Pinho, O; Domingues, V; Pinho, C; Gameiro, P

2010-10-22

88

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...

89

Determination of selected pesticides in environmental water by employing liquid-phase microextraction and liquid chromatography-tandem mass spectrometry.  

Science.gov (United States)

An optimised extraction and cleanup method for the analysis of pesticide in natural water samples is presented. Sixteen pesticides of different polarity and from the different chemical classes (organophosphates, triazines, benzimidazoles, carbamates, carbamides, neonicotinoides, methylureas, phenylureas and benzohydrazides), most frequently used in Serbia, were selected for the analysis. Liquid-phase microextraction in a single hollow fibre (HF-LPME) has been applied for sample preparation. The concentrations of pesticides were determined using HPLC-MS/MS method with electrospray ionisation. The extraction behaviour and selection of the experimental conditions was predicted based on log D and pK(a) values of targeted pesticides, which were calculated applying the computer software ACD/Labs PhysChem Suite v12. The influence of the donor pH and concentration of pesticides, organic phase composition as well as the extraction time on the extraction efficiency was investigated. Optimum extraction conditions were evaluated with respect to the investigated parameters of the extraction. The extraction method was validated for 10 out of 16 studied pesticides. Linear range of the pesticides was 0.1-5 microg L(-1) with the correlation coefficient from 0.991 to 0.9998, and the relative standard deviation for three standard measurements was between 0.2 and 11.8%. The limits of detections ranged from 0.026 to 0.237 microg L(-1) and the limits of quantifications from 0.094 to 0.793 microg L(-1). The optimised two-phase HF-LPME method was successfully applied for determination of moderately polar as well low-polar pesticides in the environmental water samples. PMID:20442990

Trti?-Petrovi?, Tatjana; Dordevi?, Jelena; Dujakovi?, Nikolina; Kumri?, Ksenija; Vasiljevi?, Tatjana; Lausevi?, Mila

2010-07-01

90

Modern pesticides and bobwhite populations  

Science.gov (United States)

Bobwhite (Colinus virginianus) are frequently used as test animals for wildlife tests of pesticides. The organophosphate and carbamate pesticides that have replaced the organochlorines have many desirable properties, but they span a wide range of acute toxicities and some of them affe,ct survival, reproduction, food consumption, behavior, and nervous system enzymes in laboratory tests. Applying these laboratory findings to the field requires assumptions about the severity of exposure in the field. Direct field measurements show that birds may be exposed to significant amounts of these pesticides or even more toxic degradation products under some conditions. Adverse population effects may also result from depression of insect populations during the seasons when bobwhites rely on insects for food.

Stromborg, K.L.

1982-01-01

91

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

92

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  

Directory of Open Access Journals (Sweden)

Full Text Available 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 as 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

2012-01-01

93

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  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 as 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 ...

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

2012-01-01

94

Evaluation of the Pollution of surface waters in the basin of west Algeria by Organo chlorine and Organophosphorus pesticides  

International Nuclear Information System (INIS)

The pollutants are pesticides which cover a whole range of chemicals designed to protect plants from pests and destroy unwanted plants. There are a very large number of pesticides and we do here that some of the major families (organo chlorine insecticides, organophosphates, carbamates, pyrethroids, phenylcyclohexyl, herbicides. (Author)

95

AN ENVIRONMENTAL TECHNOLOGY VERIFICATION (ETV) TESTING OF ENZYMATIC TEST KITS FOR WARFARE AGENTS AND PESTICIDES IN DRINKING WATER  

Science.gov (United States)

Enzymatic test kits, generally designed to be handheld and portable, detect the presence of chemical agents, carbamate pesticides, and/or organophosphate pesticides by relying on the reaction of the cholinesterase enzyme. Under normal conditions, the enzyme reacts as expected wi...

96

Development and validation of a simple GC-MS method for the simultaneous determination of 11 anticholinesterase pesticides in blood--clinical and forensic toxicology applications.  

Science.gov (United States)

Anticholinesterase pesticides are widely used, and as a result they are involved in numerous acute and even fatal poisonings. The aim of this study was the development, optimization, and validation of a simple, rapid, specific, and sensitive gas chromatography-mass spectrometry method for the determination of 11 anticholinesterase pesticides (aldicarb, azinphos methyl, carbofuran, chlorpyrifos, dialifos, diazinon, malathion, methamidophos, methidathion, methomyl, and terbufos) in blood. Only 500 ?L of blood was used, and the recoveries after liquid-liquid extraction (toluene/chloroform, 4:1, v/v) were more than 65.6%. The calibration curves were linear (R(2) ? 0.996). Limit of detections and limit of quantifications were found to be between 1.00-10.0 and 3.00-30.0 ?g/L, respectively. Accuracy expressed as the %E(r) was found to be between -11.0 and 7.8%. Precision expressed as the percent relative standard deviation was found to be <9.4%. The developed method can be applied for the investigation of both forensic and clinical cases of accidental or suicidal poisoning with these pesticides. PMID:22221006

Papoutsis, Ioannis; Mendonis, Marcela; Nikolaou, Panagiota; Athanaselis, Sotirios; Pistos, Constantinos; Maravelias, Constantinos; Spiliopoulou, Chara

2012-05-01

97

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

98

Acute pesticide poisoning and pesticide registration in Central America  

International Nuclear Information System (INIS)

The International Code of Conduct on the Distribution and Use of Pesticides of the Food and Agriculture Organization (FAO) of the United Nations has been for 20 years the most acknowledged international initiative for reducing negative impact from pesticide use in developing countries. We analyzed pesticide use and poisoning in Central America, particularly in Costa Rica and Nicaragua, and evaluated whether registration decisions are based on such data, in accordance with the FAO Code. Extensive use of very hazardous pesticides continues in Central America and so do poisonings with organophosphates, carbamates, endosulfan and paraquat as the main causative agents. Central American governments do not carry out or commission scientific risk assessments. Instead, guidelines from international agencies are followed for risk management through the registration process. Documentation of pesticide poisonings during several decades never induced any decision to ban or restrict a pesticide. However, based on the official surveillance systems, in 2000, the ministers of health of the seven Central American countries agreed to ban or restrict twelve of these pesticides. Now, almost 4 years later, restrictions have been implemented in El Salvador and in Nicaragua public debate is ongoing. Chemical and agricultural industries do not withdraw problematic pesticides voluntarily. In conclusion, the registration processes in Central America do not comply satisfactorily with the FAO Codnot comply satisfactorily with the FAO Code. However, international regulatory guidelines are important in developing countries, and international agencies should strongly extend its scope and influence, limiting industry involvement. Profound changes in international and national agricultural policies, steering towards sustainable agriculture based on non-chemical pest management, are the only way to reduce poisonings

99

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

100

Validation of a multiclass multiresidue method and monitoring results for 210 pesticides in fruits and vegetables by gas chromatography-triple quadrupole mass spectrometry.  

Science.gov (United States)

A rapid, sensitive, accurate and reliable multiresidue method for the identification and quantification of 210 relevant pesticides in four representative fruit and vegetable commodities (tomato, potato, spring onion and orange) has been developed and validated by gas chromatography in tandem with triple quadrupole mass spectrometry. The method has been fully validated and applied to 292 samples from different countries. Prior to instrumental analysis, an extraction procedure based on a sample extraction of multiclass analytes, using the ethyl acetate method was employed. Mass spectrometric conditions were individually optimized for each compound in the selected reaction monitoring (SRM) mode to achieve maximum sensitivity. The pesticides were separated in less than 25 min. This was followed by an exhaustive control of the retention times. The Retention Time Locking Method was applied, working at a constant pressure throughout the analysis. System maintenance was reduced by using a purged capillary flow device that provided backflush capabilities by reversing column flow immediately after elution of the last compound of interest. Istotopically labelled internal standards were employed to improve the quality of the analytical results. PMID:24901959

Uclés, Samanta; Belmonte, Noelia; Mezcua, Milagros; Martínez, Ana B; Martinez-Bueno, M Jesus; Gamón, Miguel; Fernández-Alba, Amadeo R

2014-01-01

 
 
 
 
101

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

102

Modification and re-validation of the ethyl acetate-based multi-residue method for pesticides in produce  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The ethyl acetate-based multi-residue method for determination of pesticide residues in produce has been modified for gas chromatographic (GC) analysis by implementation of dispersive solid-phase extraction (using primary¿secondary amine and graphitized carbon black) and large-volume (20 ¿L) injection. The same extract, before clean-up and after a change of solvent, was also analyzed by liquid chromatography with tandem mass spectrometry (LC¿MS¿MS). All aspects related to sample preparati...

Mol, J. G. J.; Rooseboom, A.; Dam, R.; Roding, M.; Arondeus, K.; Sunarto, S.

2007-01-01

103

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

104

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)

105

Development and validation of an easy multiresidue method for the determination of multiclass pesticide residues using GC-MS/MS and LC-MS/MS in olive oil and olives.  

Science.gov (United States)

Olives and olive oil are two of the most important commodities produced in the Mediterranean region. Due to their significant economical importance, the usage of pesticides in their production is systematic, by using a wide range of plant protection products with a variety of modes of action. As a consequence, monitoring of their residue levels in this products is a necessity. In the present study a gas and liquid chromatography-tandem mass spectrometry multiresidue method, with a short sample preparation step, based on acetonitrile extraction is developed and validated according to the European Union guidelines (SANCO Doc. No. 12495/2011) in olives and olive oil, with a large scope that includes pesticides of different chemical classes. Good sensitivity and selectivity of the method were obtained with limits of quantification at 10 ?g/kg. All pesticides had recoveries in the range of 70-120%, with relative standard deviation values less than 20-25%, at both validation levels. Excellent linearity was achieved with r?0,99 for both matrices. The method is easy, with low consumption of reagents, is characterized by reliability, sensitivity and therefore is suitable for the monitoring the levels of multiclass pesticides residues in olives and olive oil. The method was applied to 262 samples of the Greek market, of which 7% were found positive for the present of pesticides. In some of the samples 2-8 different analytes were detected. PMID:23708529

Anagnostopoulos, C; Miliadis, G E

2013-08-15

106

Select small core structure carbamates exhibit high contact toxicity to "carbamate-resistant" strain malaria mosquitoes, Anopheles gambiae (Akron).  

Science.gov (United States)

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 confirm that carbamate-susceptible G3 and carbamate-resistant Akron strains of An. gambiae carry wild-type (WT) and G119S AChE, respectively. G119S AgAChE was expressed and purified for the first time, and was shown to have only 3% of the turnover number (k(cat)) of the WT enzyme. Twelve carbamates were then assayed for inhibition of these enzymes. High resistance ratios (>2,500-fold) were observed for carbamates bearing a benzene ring core, consistent with the carbamate-resistant phenotype of the G119S enzyme. Interestingly, resistance ratios for two oxime methylcarbamates, and for five pyrazol-4-yl methylcarbamates were found to be much lower (4- to 65-fold). The toxicities of these carbamates to live G3 and Akron strain An. gambiae were determined. As expected from the enzyme resistance ratios, carbamates bearing a benzene ring core showed low toxicity to Akron strain An. gambiae (LC(50)>5,000 ?g/mL). However, one oxime methylcarbamate (aldicarb) and five pyrazol-4-yl methylcarbamates (4a-e) showed good to excellent toxicity to the Akron strain (LC(50)?=?32-650 ?g/mL). These results suggest that appropriately functionalized "small-core" carbamates could function as a resistance-breaking anticholinesterase insecticides against the malaria mosquito. PMID:23049714

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; Carlier, Paul R

2012-01-01

107

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

108

Cholinesterase activity depression among California agricultural pesticide applicators.  

Science.gov (United States)

Cholinesterase activity measurements for 542 California agricultural pesticide applicators under medical supervision during the first 9 months of 1985 were analyzed. Twenty-six workers, 4.8% of the sample, had cholinesterase values at or below the California threshold values for removal from continued exposure to cholinesterase-inhibiting pesticides (60% of baseline for red blood cell cholinesterase and 50% of baseline for plasma cholinesterase activity). Eight of these 26 workers, 31.5%, had pesticide-related illnesses. Pesticides most frequently associated with cholinesterase depressions exceeding California threshold values included mevinphos (Phosdrin), oxydemeton methyl (Metasystox-R), methomyl (Lannate), and acephate (Orthene); these pesticides included organophosphates in toxicity categories I and II and one carbamate in toxicity category I. PMID:2729280

Ames, R G; Brown, S K; Mengle, D C; Kahn, E; Stratton, J W; Jackson, R J

1989-01-01

109

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

110

Pesticide analysis in teas and chamomile by liquid chromatography and gas chromatography tandem mass spectrometry using a modified QuEChERS method: validation and pilot survey in real samples.  

Science.gov (United States)

This paper presents the validation of a modified QuEChERS method in four matrices - green tea, red tea, black tea and chamomile. The experiments were carried out using blank samples spiked with a solution of 86 pesticides (insecticides, fungicides and herbicides) at four levels - 10, 25, 50 and 100 ?g/kg. The samples were extracted according to the citrate QuEChERS protocol; however, to reduce the amount of coextracted matrix compounds, calcium chloride was employed instead of magnesium sulphate in the clean-up step. The samples were analysed by LC-MS/MS and GC-MS/MS. Included in the scope of validation were: recovery, linearity, matrix effects, limits of detection and quantitation as well as intra-day and inter-day precision. The validated method was used in a real sample survey carried out on 75 samples purchased in ten different countries. In all matrices, recoveries of the majority of compounds were in the 70-120% range and were characterised by precision lower than 20%. In 85% of pesticide/matrix combinations the analytes can be detected quantitatively by the proposed method at the European Union Maximum Residue Level. The analysis of the real samples revealed that large number of teas and chamomiles sold in the European Union contain pesticides whose usage is not approved and also pesticides in concentrations above the EU MRLs. PMID:23127810

Lozano, Ana; Rajski, ?ukasz; Belmonte-Valles, Noelia; Uclés, Ana; Uclés, Samanta; Mezcua, Milagros; Fernández-Alba, Amadeo R

2012-12-14

111

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.

112

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.

113

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

114

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)

115

Screening for estrogen and androgen receptor activities in 200 pesticides by in vitro reporter gene assays using Chinese hamster ovary cells.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We tested 200 pesticides, including some of their isomers and metabolites, for agonism and antagonism to two human estrogen receptor (hER) subtypes, hERalpha and hERbeta, and a human androgen receptor (hAR) by highly sensitive transactivation assays using Chinese hamster ovary cells. The test compounds were classified into nine groups: organochlorines, diphenyl ethers, organophosphorus pesticides, pyrethroids, carbamates, acid amides, triazines, ureas, and others. These pesticides were tested...

Kojima, Hiroyuki; Katsura, Eiji; Takeuchi, Shinji; Niiyama, Kazuhito; Kobayashi, Kunihiko

2004-01-01

116

Biomarkers of Sensitivity and Exposure in Washington State Pesticide Handlers  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Organophosphate (OP) and N-methyl-carbamate (CB) insecticides are widely used in agriculture in the US and abroad. These compounds – which inhibit acetylcholinesterase (AChE) enzyme activity – continue to be responsible for a high proportion of pesticide poisonings among US agricultural workers. It is possible that some individuals may be especially susceptible to health effects related to OP/CB exposure. The paraoxonase (PON1) enzyme metabolizes the highly toxic oxon forms of some OPs, a...

Hofmann, J. N.; Keifer, M. C.; Checkoway, H.; Roos, A. J.; Farin, F. M.; Fenske, R. A.; Richter, R. J.; Belle, G.; Furlong, C. E.

2010-01-01

117

Development and field validation of an indicator to assess the relative mobility and risk of pesticides in the Lourens River catchment, South Africa.  

Science.gov (United States)

A GIS based pesticide risk indicator that integrates exposure variables (i.e. pesticide application, geographic, physicochemical and crop data) and toxicity endpoints (using species sensitivity distributions) was developed to estimate the Predicted Relative Exposure (PREX) and Predicted Relative Risk (PRRI) of applied pesticides to aquatic ecosystem health in the Lourens River catchment, Western Cape, South Africa. Samples were collected weekly at five sites from the beginning of the spraying season (October) till the beginning of the rainy season (April) and were semi quantitatively analysed for relevant pesticides applied according to the local farmers spraying programme. Monitoring data indicate that physicochemical data obtained from international databases are reliable indicators of pesticide behaviour in the Western Cape of South Africa. Sensitivity analysis identified KOC as the most important parameter influencing predictions of pesticide loading derived from runoff. A comparison to monitoring data showed that the PREX successfully identified hotspot sites, gave a reasonable estimation of the relative contamination potential of different pesticides at a site and identified important routes of exposure (i.e. runoff or spray drift) of different pesticides at different sites. All pesticides detected during a monitored runoff event, were indicated as being more associated with runoff than spray drift by the PREX. The PRRI identified azinphos-methyl and chlorpyrifos as high risk pesticides towards the aquatic ecosystem. These results contribute to providing increased confidence in the use of risk indicator applications and, in particular, could lead to improved utilisation of limited resources for monitoring and management in resource constrained countries. PMID:24059975

Dabrowski, James Michael; Balderacchi, Matteo

2013-11-01

118

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

119

Comprehensive screening study of pesticide degradation via oxidation and hydrolysis.  

Science.gov (United States)

This comprehensive study focused on the reactivity of a set of 62 pesticides via oxidization by free chlorine, monochloramine, chlorine dioxide, hydrogen peroxide, ozone, and permanganate; photodegradation with UV(254); and hydrolysis at pH 2, 7, and 12. Samples were analyzed using direct injection liquid chromatography-mass spectrometry detection or gas chromatography-electron capture detection after liquid-liquid extraction. Many pesticides were reactive via hydrolysis and/or chlorination and ozonation mechanisms under typical drinking water treatment conditions, with less reactivity exhibited on average for chlorine dioxide, monochloramine, hydrogen peroxide, and UV(254). The pyrazole and organophosphorous pesticides were most reactive in general, whereas carbamates and others were less reactive. The screening study provides guidance for the pesticide/oxidation systems that are most likely to lead to degradates in water treatment and the environment. PMID:22141915

Chamberlain, Evelyn; Shi, Honglan; Wang, Tongwen; Ma, Yinfa; Fulmer, Alice; Adams, Craig

2012-01-11

120

Development of a simple and low-cost enzymatic methodology for quantitative analysis of carbamates in meat samples of forensic interest.  

Science.gov (United States)

Foods contaminated with a granulated material similar to Temik (a commercial pesticide formulation containing the carbamate insecticide aldicarb) are often involved in accidental ingestion, suicides, and homicides in Brazil. We developed a simple technique to detect aldicarb. This technique is based on the inhibition of a stable preparation of the enzyme acetylcholinesterase, and it is specially adapted for forensic purposes. It comprises an initial extraction step with the solvent methylene chloride followed by a colorimetric acetylcholinesterase assay. We propose that results of testing contaminated forensic samples be expressed in aldicarb equivalents because, even though all other carbamates are also potent enzyme inhibitors, aldicarb is the contaminant most frequently found in forensic samples. This method is rapid (several samples can be run in a period of 2 h) and low cost. This method also proved to be precise and accurate, detecting concentrations as low as 40 microg/kg of aldicarb in meat samples. PMID:20345797

Sabino, Bruno Duarte; Torraca, Tathiana Guilliod; Moura, Claudia Melo; Rozenbaum, Hannah Felicia; de Castro Faria, Mauro Velho

2010-05-01

 
 
 
 
121

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 ...

122

Radiotracer Approaches to Carbamate Insecticide Toxicology  

International Nuclear Information System (INIS)

n 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)

123

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

124

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

125

NMDA antagonists exert distinct effects in experimental organophosphate or carbamate poisoning in mice  

International Nuclear Information System (INIS)

Organophosphate (OP) and carbamate acetylcholinesterase (AChE) inhibitors produce seizures and lethality in mammals. Anticonvulsant and neuroprotective properties of N-methyl-D-aspartate (NMDA) antagonists encourage the investigation of their effects in AChE inhibitor-induced poisonings. In the present study, the effects of dizocilpine (MK-801, 1 mg/kg) or 3-((RS)-2-carboxypiperazin-4-yl)-propyl-1-phosphonic acid (CPP, 10 mg/kg), alone or combined with muscarinic antagonist atropine (1.8 mg/kg), on convulsant and lethal properties of an OP pesticide dichlorvos or a carbamate drug physostigmine, were studied in mice. Both dichlorvos and physostigmine induced dose-dependent seizure activity and lethality. Atropine did not prevent the occurrence of convulsions but decreased the lethal effects of both dichlorvos and physostigmine. MK-801 or CPP blocked or attenuated, respectively, dichlorvos-induced convulsions. Contrariwise, NMDA antagonists had no effect in physostigmine-induced seizures or lethality produced by dichlorvos or physostigmine. Concurrent pretreatment with atropine and either MK-801 or CPP blocked or alleviated seizures produced by dichlorvos, but not by physostigmine. Both MK-801 and CPP co-administered with atropine enhanced its antilethal effects in both dichlorvos and physostigmine poisoning. In both saline- and AChE inhibitor-treated mice, no interaction of the investigated antidotes with brain cholinesterase was found. The data indicate that both muscarinic ACh and NMDA receptor-mediated mechanisms contribute to the acute toxicity of AChE inhibitors, and NMDA receptors seem critical to OP-induced seizures

126

Validation of user- and environmentally friendly extraction and clean-up methods for compound-specific stable carbon isotope analysis of organochlorine pesticides and their metabolites in soils.  

Science.gov (United States)

In order to evaluate the potential of compound-specific stable carbon isotope analysis (CSIA) for tracking organochlorine pesticides in soil systems, sample pre-treatment methods have to be developed, which can provide recoveries sufficient for low detection limits without altering the isotope ratio of the target compounds. In this study we tested the compatibility of CSIA with user- and environmentally friendly extraction methods, including the Quick, Easy, Cheap, Effective, Rugged and Safe procedure (QuEChERS), Ultrasonic Assisted Extraction (USE) and Focused Ultrasonic Extraction (FUSE), as well as clean-up methods, including sulfuric acid clean-up and Florisil(®) column chromatography for hexachlorocyclohexanes (HCHs), p,p'-dichlorodiphenyltrichloroethane (DDT) and their environmental metabolites (chlorinated benzenes, dichlorodiphenyldichloroethylene - DDE and dichlorodiphenyldichloroethane - DDD) in soils. We optimized the extraction methods for maximum recovery and pre-concentration. At optimal conditions, all extraction methods and clean-up procedures, as well as the pre-concentration of the extract by solvent evaporation, led to insignificant changes in carbon isotope ratios of the target compounds. We modified the USE procedure to increase the volume of withdrawn organic extract, resulting in a higher pre-concentration of the target compounds by the subsequent solvent evaporation step. This Modified Ultrasonic Assisted Extraction (MUSE) was the most suitable procedure, and it was validated for the determination of carbon isotope ratios of the target compounds using two different types of soil matrices. The method could be applied to analyze carbon isotope ratios of HCHs, DDT, and their chlorinated metabolites in soil samples with concentrations ranging from 0.3 to 0.8mg/kg. The analytical uncertainty of MUSE, incorporating both accuracy and precision, was ?0.4‰. PMID:24980091

Ivdra, Natalija; Herrero-Martín, Sara; Fischer, Anko

2014-08-15

127

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

128

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

129

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

130

Dog poisoning with furadan 35-ST (carbamate insecticide  

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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

131

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

132

Total synthesis without protecting groups: pyrrolidines and cyclic carbamates.  

Science.gov (United States)

A protecting group free synthesis of 2,3-cis substituted hydroxypyrrolidines is reported. Two novel reaction methodologies allow for the stereoselective formation of cyclic carbamates from olefinic amines, and the formation of primary amines via a Vasella/reductive amination reaction, both performed in aqueous media. PMID:19105656

Dangerfield, Emma M; Timmer, Mattie S M; Stocker, Bridget L

2009-02-01

133

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

134

Pesticide contamination of the coastline of Martinique.  

Science.gov (United States)

In January and February 2002, the presence of certain agricultural pesticides throughout the coastline of the Caribbean island of Martinique was investigated. The tropical climate of the French West Indies is suitable for banana production, which requires intensive use of pesticides. An inventory of all pesticides used on the island (compounds and tonnage) was compiled. Surveys and analyses revealed the presence of pesticides in the plumes of seven rivers. The organochlorine chlordecone and metabolites of aldicarb were detected at nearly all of the monitored sites, even though the use of chlordecone has been prohibited since 1993. Two triazines (ametryn and simazine) were also identified. The concentrations of carbamates and triazines detected in the water and sediment samples from Martinique are comparable to those reported for mainland France. Chlordecone concentrations in the sediment and particulate matter samples were, however, particularly high in the samples from Martinique. Toxicological implications are discussed. Of particular concern are the high levels of chlordecone (which is bioaccumulating and carcinogenic) and further monitoring of this compound is recommended, especially in fish and other sea-food products. PMID:16045943

Bocquené, Gilles; Franco, Alain

2005-01-01

135

Pesticide Poisoning  

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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

136

Pesticide Poisoning  

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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

137

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 ...

138

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

139

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

140

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

 
 
 
 
141

Use of pralidoxime without atropine in rivastigmine (carbamate) toxicity.  

Science.gov (United States)

Some experimental models suggest that the use of pralidoxime in carbamate toxicity is deleterious. Although pretreatment with atropine minimizes the adverse effect of pralidoxime reported in these models, concerns over the risks of pralidoxime in humans with carbamate poisoning continue. We present a unique case of carbamate toxicity treated successfully with pralidoxime alone. An 80-year-old woman with Alzheimer's dementia presented to the emergency department with 3-4 days of lightheadedness, vomiting, diarrhea, and bilateral lower extremity muscle pain. Extensive review of systems was otherwise negative. Her vital signs were BP, 207/85 mmHg; pulse, 101 beats/min; rectal temperature, 36.6( degrees )C; respirations, 18/min; and SpO(2), 95% breathing room air. Her bedside glucose measurement was 6.7 mmol/L. Physical examination revealed a confused, diaphoretic, ill-appearing woman with miosis and fasciculations of the tongue, eyelids, gastrocnemius and quadriceps bilaterally. The heart, lung, abdominal and head, eyes, ears, nose and throat examinations were otherwise unremarkable. Nine 5-cm(2) rivastigmine patches (9.5 mg/24-hour) were found adherent to her torso and lower extremities. The patches were immediately removed and underlying skin cleansed with soap and water. Laboratory values including complete blood count, basic metabolic panel, calcium, magnesium, phosphorus, troponin, coagulation studies and urinalysis were unremarkable. Due to the absence of pulmonary muscarinic findings, no atropine was administered. However, 1 g of pralidoxime was administered intravenously over 30 min to treat fasciculations. Within 30 min of this treatment, there was significant improvement in symptoms and resolution of fasciculations. She was admitted to the hospital, required no further pralidoxime therapy and was discharged after 3 days. Rivastigmine is a reversible (carbamate) cholinesterase inhibitor used to treat dementia. In overdose, cholinergic crisis is expected and in this case was precipitated by patch overuse. We believe there was a causal relationship between pralidoxime administration and the prompt resolution of symptoms and fasciculations. This case of apparently safe and effective pralidoxime use without concomitant atropine administration in a patient with carbamate toxicity reinforces recent data demonstrating the potential safety of pralidoxime in carbamate toxicity. PMID:19755437

Hoffman, R S; Manini, A F; Russell-Haders, A L; Felberbaum, M; Mercurio-Zappala, M

2009-09-01

142

Pesticide residues in honeybees, honey and bee pollen by LC-MS/MS screening: reported death incidents in honeybees.  

Science.gov (United States)

The aim of this study was to investigate reported cases of honeybee death incidents with regard to the potential interrelation to the exposure to pesticides. Thus honeybee, bee pollen and honey samples from different areas of Greece were analyzed for the presence of pesticide residues. In this context an LC-ESI-MS/MS multiresidue method of total 115 analytes of different chemical classes such as neonicotinoids, organophosphates, triazoles, carbamates, dicarboximides and dinitroanilines in honeybee bodies, honey and bee pollen was developed and validated. The method presents good linearity over the ranges assayed with correlation coefficient values r(2)?0.99, recoveries ranging for all matrices from 59 to 117% and precision (RSD%) values ranging from 4 to 27%. LOD and LOQ values ranged - for honeybees, honey and bee pollen - from 0.03 to 23.3 ng/g matrix weight and 0.1 up to 78 ng/g matrix weight, respectively. Therefore this method is sufficient to act as a monitoring tool for the determination of pesticide residues in cases of suspected honeybee poisoning incidents. From the analysis of the samples the presence of 14 active substances was observed in all matrices with concentrations ranging for honeybees from 0.3 to 81.5 ng/g, for bee pollen from 6.1 to 1273 ng/g and for honey one sample was positive to carbendazim at 1.6 ng/g. The latter confirmed the presence of such type of compounds in honeybee body and apicultural products. PMID:24747255

Kasiotis, Konstantinos M; Anagnostopoulos, Chris; Anastasiadou, Pelagia; Machera, Kyriaki

2014-07-01

143

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.

144

Antimicrobial Pesticides  

Science.gov (United States)

This newly launched site from the US Environmental Protection Agency (EPA) offers a variety of resources describing how the EPA regulates antimicrobial pesticides. Antimicrobial pesticides are used in a huge variety of household and commercial products to "disinfect, sanitize, reduce, or mitigate growth or development of microbiological organisms" and to "protect inanimate objects (for example floors and walls), industrial processes or systems, surfaces, water, or other chemical substances from contamination, fouling, or deterioration caused by bacteria, viruses, fungi, protozoa, algae, or slime." Intended mainly for a regulatory audience, the site includes Antimicrobials Science Policy Documents, Antimicrobials Registration Policy Documents, Label Review Manual, Chemical/ Registration Number Indexes, and Antimicrobial PR notices.

145

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 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

146

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

147

Cleavable carbamate linkers for controlled protein delivery from hydrogels.  

Science.gov (United States)

The reversible attachment of proteins to polymers is one potential strategy to control protein release from hydrogels. In this study, we report the reversible attachment of lysozyme to poly(ethylene glycol) (PEG) by degradable carbamate linkers. Phenyl groups with different substituents were used to control the rate of carbamate hydrolysis and the resulting protein release. Sodium dodecyl sulfate polyacrylamide gel electrophoresis showed modification with 1-3 PEG chains per lysozyme molecule. Protein PEGylation and PEG chain elimination occurred without changes in secondary protein structure, as demonstrated by circular dichroism spectroscopy. The lytic activity of lysozyme was restored to 73.4±1.7%-92.5±1.2% during PEG chain elimination. Attached PEG chains were eliminated within 24h to 28days, depending on the used linker molecule. When formulated into hydrogels, a maximum of about 60% of the initial dose was released within 7days to 21days. Linker elimination occurs 'traceless', so that the protein is released in its native, unmodified form. Altogether, we believe that tethering proteins by degradable carbamate linkers is a promising strategy to control their release from hydrogels. PMID:24680687

Hammer, Nadine; Brandl, Ferdinand P; Kirchhof, Susanne; Goepferich, Achim M

2014-06-10

148

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

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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

149

Chemicals - Pesticides  

Feb 9, 2010 ... Pesticides have an important role in controlling a variety of pests, weeds, ... Defra \\has policy responsibility in England for plant protection products ... such as on \\houseplants, garden roses and lawns); In or near water (e.g. on ...

150

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

151

The carbamate equilibrium of bovine hemoglobin at 37 degrees C.  

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emoglobin-bound CO2 was estimated by a procedure first described by Rossi-Bernardi et al. (1969) in which the carbamate compound is stabilized by rapid mixing with alkali and then separated from other CO2 constituents in solution by gel filtration and ion-exchange chromatography. Carbamate equilibrium of bovine hemoglobin was studied at constant PCO2 (44 mm Hg) and varying pH as well as at constant pH (7.4) and varying PCO2 (ionic strength 0.18, temperature 37.0 degrees C). The difference in Z (deltaZ) between hemoglobin and oxyhemoglobin appeared to be 0.11 plus or minus 0.04 (pH=7.40; PCO2=44 mm Hg) i.e. about half the value observed in human hemoglobin. DeltaZ was shown to account completely for the difference in CO2 content (CCO2) between hemoglobin and oxyhemoglobin when in total equilibrium with CO2. Carbamate determinations on bovine hemoglobin specifically modified at all terminal amino groups (double-blocked carbamylated derivative) did not show any CO2 binding at all, thus giving a final proof for the exclusive role of the terminal amino groups in CO2 binding under physiological conditions. Attempts to calculate the ionization constant (Kz) and the carbamate equilibrium constant (Kc) of the terminal amino groups failed, suggesting that both terminal groups are not equivalent in their CO2 binding properties. This was confirmed by the fact that carbamate data obtained at constant PCO2 and varying pH fitted binding curves derived from two sets of independent but non-equivalent binding sites. Association constants for both kinds of binding sites appeared to differ by a factor of at least 3 in hemoglobin and of about 10 in oxyhemoglobin. From determinations of hemoglobin-bound CO2 and CO2 content of hemoglobin and oxyhemoglobin solutions in total equilibrium with CO2, the apparent first dissociation constant of carbonic acid was calculated as 5.71 plus or minus 0.0061 pH and found to be independent of the oxygenation state of hemoglobin. In contrast with hemoglobin of other species bovine hemoglobin appeared to be not influenced by the presence of 2.3-diphosphoglycerate as far as its CO2-binding properties are concerned. PMID:238266

Van Kempen, L H; Breepoel, P M; Kreuzer, F

1975-03-01

152

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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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 Ext...

Altorshani, Ahmed A.; Bakar, Nor K. A.; Eid, Eltayeb E. M.

2010-01-01

153

[Reactivity of several classes of pesticides with UV, ozone and permanganate].  

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The reactivity of eight classes of 26 extensively used pesticides, namely, organochlorines, thiadiazole, dinitroanaline, acetamides, triazines, uracil and carbamates, with three common disinfectants or oxidants including UV254 (average intensity of 10.8 mW x cm(-2)), ozone (dosage of 4.1 - 6.2 mg x L(-1)) and permanganate (dosage of 15.8 mg x L(-1)) was investigated. The reactions were allowed to proceed for 30 min at pH 7.0 and ambient temperature (25 degrees C +/- 3 degrees C). Results indicate that under the applied experimental conditions, more than 95% of chlorobenzilate, etridiazole, alachlor, butachlor, metolachlor, propachlor, atrazine, simazine, aldicarb, oxamyl and methiocarb could be effectively removed by UV254; and the removal efficiencies of other pesticides were in a range of 12.9%-77.7%. Ozone could completely degrade chloroneb, dichlorvos, bromacil, aldicarb, carbaryl, carbofuran, oxamyl and methiocarb; prometon and aldicarb sulfone were resistant to ozonation; and the removal efficiencies of other pesticides varied from 19.0% to 93.1%. Permanganate could fully degrade dichlorvos, aldicarb and methiocarb; organochlorines, dinitroanaline, thiadiazole, acetamides and other carbamates were resistant to permanganate oxidation; and the removal efficiencies of other pesticides ranged from 16.0% to 88.2%. If the practical dosage applied in drinking water treatment is considered, it is expected that most of the pesticides will be completely degraded by ozone, a few by permanganate, but probably none by UV254 . PMID:19353869

Liu, Chao; Qiang, Zhi-min; Tian, Fang; Zhang, Tao

2009-01-01

154

Electrochemical biosensor technology: application to pesticide detection.  

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In recent years, electrochemical sensors and biosensors are becoming an accepted part of analytical chemistry since they satisfy the expanding need for rapid and reliable measurements. An area in which electrochemical biosensors perhaps show the greatest diversity and potential for development involves the measurement of environmentally significant parameters. The increasing number of pollutants in the environment calls for fast and cost-effective analytical requirements. In this context, biosensors appear as suitable alternative or complementary analytical tools. The aim of this chapter is to review some basic concept concerning the electrochemical biosensors and to illustrate a protocol for the detection of environmental organic pollutants on the basis of electrochemical biosensors. In particular, a method based on the inhibition of the enzyme acetylcholinesterase (AChE) for the detection of organophosphorus and carbamate pesticides will be described in detail. PMID:19159094

Palchetti, Ilaria; Laschi, Serena; Mascini, Marco

2009-01-01

155

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

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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

156

Development, validation and application of a methodology based on solid-phase micro extraction followed by gas chromatography coupled to mass spectrometry (SPME/GC-MS) for the determination of pesticide residues in mangoes.  

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A method was developed for the simultaneous analysis of 14 pesticide residues (clofentezine, carbofuran, diazinon, methyl parathion, malathion, fenthion, thiabendazole, imazalil, bifenthrin, permethrin, prochloraz, pyraclostrobin, difenoconazole and azoxystrobin) in mango fruit, based on solid-phase micro extraction (SPME) coupled to gas chromatography-mass spectrometry (GC-MS). Different parameters of the method were evaluated, such as fiber type, extraction mode (direct immersion and headspace), temperature, extraction and desorption times, stirring velocities and ionic strength. The best results were obtained using polyacrylate fiber and direct immersion mode at 50 degrees C for 30 min, along with stirring at 250 rpm and desorption for 5 min at 280 degrees C. The method was validated using mango samples spiked with pesticides at concentration levels ranging from 33.3 to 333.3 microg kg(-1). The average recoveries (n=3) for the lowest concentration level ranged from 71.6 to 117.5%, with relative standard deviations between 3.1 and 12.3%, respectively. Detection and quantification limits ranged from 1.0 to 3.3 microg kg(-1) and from 3.33 to 33.33 microg kg(-1), respectively. The optimized method was then applied to 16 locally purchased mango samples, all of them containing the pesticides bifenthrin and azoxystrobin in concentrations of 18.3-57.4 and 12.7-55.8 microg kg(-1), respectively, although these values were below the MRL established by Brazilian legislation. The method proved to be selective, sensitive, and with good precision and recovery rates, presenting LOQ below the MRL admitted by Brazilian legislation. PMID:20188930

Menezes Filho, Adalberto; dos Santos, Fábio Neves; Pereira, Pedro Afonso de Paula

2010-04-15

157

Safe Storage of Pesticides  

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Safe Storage of Pesticides Esta página Web está disponible en español Improper pesticide storage and disposal can be hazardous to human health ... Follow these safety recommendations: Don't stockpile. Reduce storage needs by buying only the amount of pesticide ...

158

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.  

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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

159

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.  

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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

160

Dietary exposure of Hong Kong adults to pesticide residues: results of the first Hong Kong total diet study.  

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The use of pesticides and other chemicals has become a common practice in modern agriculture to enhance and stabilise crop yield, protect the nutritional integrity of food, facilitate food storage to assure year-round supplies, and provide attractive and appealing food products. With the adoption of strict good agricultural practice (GAP), only minimal amounts of pesticide residues should remain on the crops or in connected foods of animal origin up the food chain. To assess their associated health risk to local people, the dietary exposure of Hong Kong adults to residues of four groups of pesticides or their metabolites - organophosphorus pesticides (OPPs), carbamates, pyrethrins and pyrethroids, and dithiocarbamate (DTC) metabolites - is estimated in the first Hong Kong Total Diet Study (TDS). A total of 150 commonly consumed food items were collected and prepared "as consumed". A total of 600 composite food samples were analysed for 85 pesticides or their metabolites by liquid chromatography-tandem mass spectrometry (LC-MS/MS). These pesticides were primarily found at low levels (highest mean = 350 ?g kg(-1)) in food samples of plant origin such as vegetables and fruits. Dietary exposures to pesticide residues were estimated based on the analytical results and the food consumption data of the local residents. The estimated dietary exposures of Hong Kong adults to all individual pesticides were well below their respective acceptable daily intakes (ADIs). The percentage contributions of the estimated mean and 95th percentile dietary exposures to the ADIs of individual pesticides were <6% and <24% for the OPPs, <1% for the carbamates and pyrethrins and pyrethroids, and <1% and <4% for the DTC metabolites, respectively. The findings indicate that dietary exposures to all the pesticide residues analysed in this study were unlikely to pose unacceptable health risks to the Hong Kong population. PMID:24588687

Wong, Waiky W K; Yau, Arthur T C; Chung, Stephen W C; Lam, Chi-ho; Ma, Stephanie; Ho, Y Y; Xiao, Ying

2014-01-01

 
 
 
 
161

Development of a fieldable rapid pesticide exposure analysis sensing system  

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Despite the recent interest in organically grown foods, most agricultural crops use multiple pesticides to optimize yield. There are many persons whose health may be affected by the spraying; there is the active applicator and the passive neighbors. In between these extremes are the farm workers who pick the crops anywhere from days to weeks after application. How much pesticide residue are these workers exposed to during a workday and how much is transferred back to the residence? Despite the low vapor pressures, what is the true concentration of pesticides surrounding a person when pesticides adsorbed to particulate matter are included? What is the relationship between the concentration around an individual and the amount adsorbed/ingested? To answer these questions on a statistically significant scale in actual field conditions, a portable, fast, inexpensive measurement device is required. We present herein results obtained using Surface-Enhanced Raman Spectroscopy (SERS) that demonstrate the capability to detect < 100 organophosphate, organochlorine and carbamate-based pesticides in the vapor phase as well as the ability of SERS sensors to detect a particular analyte in a synthetic urine matrix. We will also present data collected from CDC quantified urine samples and will present results obtained in a field test wherein SERS sensors wore worn as dosimeters in the field and real-time vapor sampling of the farm workers barracks was performed. The issue of potential interferences will also be discussed.

Spencer, Kevin M.; Clauson, Susan L.; Spencer, Sarah A.; Sylvia, James M.; Vallejos, Quirina M.; Quandt, Sara A.; Arcury, Thomas A.

2010-04-01

162

Treatment rationale for dogs poisoned with aldicarb (carbamate pesticide : clinical review  

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Full Text Available The treatment rationale for dogs poisoned by aldicarb is reviewed from a pharmacological perspective. The illegal use of aldicarb to maliciously poison dogs is a major problem in some parts of the world. In South Africa, it is probably the most common canine poisoning treated by companion animal veterinarians. Aldicarb poisoning is an emergency and veterinarians need to be able to diagnose it and start with effective treatment immediately to ensure a reasonable prognosis. Successful treatment depends on the timely use of an anti-muscarinic drug (e.g. atropine. Additional supportive treatment options, including fluid therapy, diphenhydramine, benzodiazepines and the prevention of further absorption (activated charcoal should also be considered. Possible complications after treatment are also briefly discussed.

J. G. Myburgh

2012-05-01

163

[Toxicity of several pesticides used in Tunisia, for Aphanius fasciatus Nardo, 1827 (Pisces, Cyprinodontidae.)].  

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The acute toxicity of some pesticides used in Tunisia is determined for the species Aphanius fasciatus (Pisces - Cyprinodontidae). Bioassays conducted at temperature (19-20 degrees C) and salinity (37-38%) have allowed to calculate the CL50 48 h and 96 h. The classification of these pesticides, based on the CL50 96 h, and according to their toxicity for the test species, shows that the organic phosphorus (Murphotox, Bazudin, Dursban, Zithiol, Lebaycid, Imidan, Oleoparathion, Folimat; Nuvan, Actellic, Carbicron, Nexion, Dimecron, Roxion) have all the degrees of toxicity, but the majority are among the most toxic; the carbamates (Betanal, Dimetilan, Baygon), are generally less toxic than the organic phosphorus tested, except Nexion which is less toxic than the Betanal and Roxion less toxic than the three carbamates tested; the herbicides (2,4-D, Basagran, Printan) have a very low toxicity, and are less toxic than the insecticides tested, except Betanal and Suffix of which the toxicity is higher than some insecticides (Nexion, Dimecron, Baygon, Dimetilan, Roxion); Calixin (Fongicide) is more toxic than the herbicides tested but it is generally less toxic than the insecticides used. At higher temperature (28-29 degrees C) A. fasciatus is more sensible to organic phosphorus (Dursban, Folimat) than to carbamate (Betanal). The variation change of salinity (from 37 to 6.5 %) don't modify the sensibility of the test species face to face of three pesticides: Dursban, Folimat (organic phosphorus insecticide) and Betanal (carbamate herbicide). A. fasciatus is suitable for acute and chronic bioassays. PMID:555295

Boumaiza, M; Ktari, M H; Vitiello, P

1979-09-01

164

Analytical survey of N-nitroso contaminants in pesticide products.  

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1. Levels of N-nitroso dialkylamines in dinitroaniline derivatives were high (up to 153 mg/kg) in the past, but have been decreased considerably in current production, due to process changes. 2. Butralin and pendimethalin contain significant amounts of N-nitroso parent compounds. 3. Most dimethylamine salts of phenoxyalkanoic acids presently contain low or non-detectable levels of NDMA. 4. Quaternary ammonium compounds contain NDMA levels up to 16.8 mg/kg. 5. Two morpholine derivatives appear to contain N-nitrosomorpholine. 6. The triethanolamine salt of dinoseb contains over 200 mg/kg N-nitrosodiethanolamine. 7. A large number of amides, carbamates, organophosphates, triazines, urea derivatives and miscellaneous nitrogen-containing pesticides do not contain N-nitrosamines above 1 mg/kg. 8. Most N-nitroso contaminants in pesticides can be avoided by simple process changes and the elimination of nitrite salts in the formulation. PMID:7228279

Zweig, G; Selim, S; Hummel, R; Mittelman, A; Wright, D P; Law, C; Regelman, E

1980-01-01

165

Acetylcholinesterase Based Detection of Residual Pesticides on Cotton  

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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

166

Assessment of pesticide pollution in suburban soil in south Shenyang, China.  

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In this study, 35 representative farmland soil samples from suburban areas in south Shenyang, the capital city in Liaoning province, China, were collected to evaluate the pollution of 114 pesticides. Surface soil samples were air-dried and sieved. Ultrasonic extraction was used for pesticides preparation prior to analysis with gas chromatography-mass spectrometry. The total concentrations of tested pesticides in the area ranged in 0-51.32 ng/g and the average of concentrations was 6.86 ng/g. Six pesticides, including butachlor(with detect frequency 71.4%), p,p'-DDE (88.6%), p,p'-DDT (77.1%), o,p'-DDD (82.9%), hexachlorobenzene (88.6%) and ?-HCB (77.1%), were detected most frequently. It indicated that DDTs (N.D.-40.25 ng/g) and HCHs (N.D.-42.79 ng/g) were the predominant pesticide pollutants in soil because of their long term persistence. On the contrary, most of organophosphorus pesticides, pyrethroids and carbamates were not detected. Spatial variation of six pesticides with high detection frequency (>70%) in soil was illustrated. Pollution levels, characteristics and the possible sources were also discussed. The data were helpful to figure out the pollution of the pesticides and could be further used to evaluate the health risk associated with food safety. PMID:21909625

Shi, Rongguang; Lv, Jungang; Feng, Jimin

2011-11-01

167

Pesticide poisoning in domestic animals and livestock in Austria: a 6 years retrospective study.  

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A 6 years retrospective study of pesticide poisonings in domestic animals and livestock from 1999 to 2004 submitted to the Institute for Medical Chemistry, University of Veterinary Medicine, Vienna in Austria was compiled and analysed. Totally 380 pesticide analysis requests were referred by veterinary practitioners, from the Institute for Pathology of the above university, by regional and central governments as well as local police departments and district administrations, animal protectionist groups, public health authorities and private clients. Among the total number of suspected samples for pesticides, 175 (46.1%) cases were found positive to contain pesticides of various kinds. Among the pesticides found, carbamate insecticides were most prominent, representing 50.3% of the total positive cases. These compounds were followed by rodenticides-anticoagulants with 18.9% of the positive results, by organophosphate insecticides 5.1%, and by the rodenticides-nonanticoagulant 3.4%, the other 22.3% included molluscicides, herbicides, etc. In totally 225 animals, 123 animals were found positive for pesticide intoxication, among them 47.2% were dogs, 34.1% were cats 9.8% of other species and 8.9% of unspecified animal samples. The pesticides were characterized by HPLC-techniques using commercially available standards. The aim of this Austrian survey was to determine the incidence and frequency of confirmed pesticide intoxications in animals in Austria and to emphasize its relevance in veterinary practice for livestock and domestic animals. PMID:16997525

Wang, Yingzi; Kruzik, Paul; Helsberg, Albert; Helsberg, Inge; Rausch, Wolf-Dieter

2007-07-01

168

New screening approach for risk assessment of pesticides in ambient air  

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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 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

169

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

170

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

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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

171

Pesticide poisoning.  

Science.gov (United States)

Acute poisoning with pesticides is a global public health problem and accounts for as many as 300,000 deaths worldwide every year. The majority of deaths occur due to exposure to organophosphates, organochlorines and aluminium phosphide. Organophosphate compounds inhibit acetylcholinesterase resulting in acute toxicity. Intermediate syndrome can develop in a number of patients and may lead to respiratory paralysis and death. Management consists of proper oxygenation, atropine in escalating doses and pralidoxime in high doses. It is Important to decontaminate the skin while taking precautions to avoid secondary contamination of health personnel. Organochlorine pesticides are toxic to the central nervous system and sensitize the myocardium to catecholamines. Treatment involves supportive care and avoiding exogenous sympathomimetic agents. Ingestion of paraquat causes severe inflammation of the throat, corrosive injury to the gastrointestinal tract, renal tubular necrosis, hepatic necrosis and pulmonary fibrosis. Administration of oxygen should be avoided as it produces more fibrosis. Use of immunosuppressive agents have improved outcome in patients with paraquat poisoning. Rodenticides include thallium, superwarfarins, barium carbonate and phosphides (aluminium and zinc phosphide). Alopecia is an atypical feature of thallium toxicity. Most exposures to superwarfarins are harmless but prolonged bleeding may occur. Barium carbonate Ingestion can cause severe hypokalaemia and respiratory muscle paralysis. Aluminium phosphide is a highly toxic agent with mortality ranging from 37% to 100%. It inhibits mitochondrial cytochrome c oxidase and leads to pulmonary and cardiac toxicity. Treatment is supportive with some studies suggesting a beneficial effect of magnesium sulphate. Pyrethroids and insect repellants (e.g. diethyltoluamide) are relatively harmless but can cause toxic effects to pulmonary and central nervous systems. Ethylene dibromide-a highly toxic, fumigant pesticide-produces oral ulcerations, followed by liver and renal toxicity, and is almost uniformly fatal. Physicians working in remote and rural areas need to be educated about early diagnosis and proper management using supportive care and antidotes, wherever available. PMID:18085124

Goel, Ashish; Aggarwal, Praveen

2007-01-01

172

Intoxicación por plaguicidas Pesticide poisoning  

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Full Text Available 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 (insecticidas, 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.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, raticides… 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

2003-01-01

173

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.

174

New water-soluble carbamate ester derivatives of resveratrol.  

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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

175

New Water-Soluble Carbamate Ester Derivatives of Resveratrol  

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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

176

Distribution and determinants of pesticide mixtures in cord serum using principal component analysis.  

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We characterized the distribution and determinants of fetal exposures to pesticide mixtures using a cross-sectional study of 297 singletons delivered at Johns Hopkins Hospital in Baltimore, MD (2004-2005). Concentrations of nine persistent and twelve nonpersistent pesticides were measured in cord serum. Mixtures were identified using principal components analysis. Associations between mixtures and maternal and infant characteristics were evaluated using multivariate analysis. p,p'-DDE, p,p'-DDT, trans-nonachlor, oxychlordane, bendiocarb, propoxur, and trans- and cis-permethrin were detected in 100, 90, 93, 84, 73, 55, 52, and 41% of serum samples, respectively. There were four independent pesticide components: DDT (p,p'-DDT + p,p'-DDE), chlordane (trans-nonachlor + oxychlordane), permethrin (trans- and cis-permethrins + PBUT), and carbamate (bendiocarb + propoxur). DDT and chlordane were 6.1 (95%CI: 2.4, 15.5) and 2.1 (95%CI: 1.0, 4.2) times higher for infants of women >35, and 1.8 (95%CI: 1.2, 2.9) and 1.5 (95%CI: 1.1, 2.1) times higher in smoking mothers. DDT and carbamate were 15 (95%CI: 7, 30) and 2 (95%CI: 1, 4) times higher for infants of Asian compared with Caucasian mothers. No significant differences were observed for permethrin. Fetal exposures to pesticides are widespread, occur as mixtures, and differ by maternal race, age, and smoking status. PMID:20550184

Neta, Gila; Goldman, Lynn R; Barr, Dana; Sjödin, Andreas; Apelberg, Benjamin J; Witter, Frank R; Halden, Rolf U

2010-07-15

177

Disposal of obsolete pesticides, the case of Ethiopia.  

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Ethiopia has accumulated obsolete pesticide stocks since pesticides were first imported in the 1960s due to prolonged storage of pesticides, inappropriate storage conditions because of poor storage facilities, the lack of trained staff and lack of national legislation for pesticide registration and monitoring system of pesticide use in the country. The first pesticide inventory conducted in 1995 led by FAO in collaboration with the government of Ethiopia had identified about 426 tonnes of obsolete pesticides mainly on state-owned agricultural farms and held by the Ministry of Health. However, these stocks have increased to over 1500 tonnes (including 200 active ingredients) as found in a detailed inventory conducted in 1999. The stocks included organochlorines (258.3 tonnes), organophosphates (155.4 tonnes), carbamates (58.5 tonnes), coumarines (14.9 tonnes), inorganics (30.2 tonnes), others (257.2 tonnes), mixed pesticides (70.4 tonnes) and unknown pesticides (307.1 tonnes) including both liquid and solid state formulations. The obsolete organochlorine pesticides stocks were mostly pesticides such as chlordane, DDT, dieldrin and lindane that are banned or restricted in most countries. The highest amount of a single active ingredient found was the organophosphate insecticide pirimiphos methyl (172.1 tonnes). All these stocks were disposed of in the first phase of disposal in Finland (during 2000-2003) by the hazardous waste management company Ekokem at a cost of about US$ 4.44 million. Another 1000 tonnes of obsolete pesticides have been identified and are currently being eliminated in a second disposal phase at a total cost of US$ 8,135,500. Along with the disposal process, a number of activities are being implemented to prevent future pesticides accumulation. These activities include the development and enforcement of pesticide policy, the implementation of Integrated Pest Management (IPM) and Integrated Vector Management (IVM), capacity building in terms of providing professional trainings, creating awareness among stakeholders on the environmental and human health hazard posed by obsolete pesticides as well as other actions to prevent their accumulation and enforcement of national legislations and policies related to pesticides use. However, pesticide use in the country is increasing. For instance, 12 years of pesticides import data (1996-2007) by the Ministry of Agriculture shows that 2973 tonnes of pesticides were imported between 1996-1998, 3670 tonnes between 1999-2001, 5079 tonnes between 2002-2004 and 8302 tonnes between 2005-2007. Moreover, 6 years of insecticide import data (1996/97-2001/02) by the Ministry of Health shows that around 919 tonnes of insecticides were imported between 1996/97-1997/98, 812 tonnes between 1998/99-1999/00 and 970 tonnes between 2000/01-2001/02 for malaria and other vector borne diseases control. PMID:19073344

Haylamicheal, Israel D; Dalvie, Mohamed A

2009-04-01

178

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

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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 (Km = 77.2 mM; Vmax = 38.2 mU/mg protein) and 1-naphthyl acetate (Km = 222 mM, Vmax = 1095 mU/mg protein) substrates, respectively. Acetylcholinesterase activity was concentration-dependently inhibited by chlorpyrifos-oxon, dichlorvos, carbaryl and carbofuran (IC50 = 1.35 x 10-5-3.80 x 10-8 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 10-5-2.98 x 10-8 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

179

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

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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

180

Fatal pesticides poisoning in Morocco (2000–2005 Intoxications mortelles aux pesticides au Maroc (2000–2005  

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Full Text Available Introduction: Acute poisoning by pesticides become more and more frequent, it's an important cause of morbidity and mortality worldwide. The aim of our study was to determine the epidemiological profile of fatal pesticide poisoning deaths in Morocco between 2000 and 2005. Materials and methods: A retrospective study, covering the period from January 2000 to December 2005 was based on database of Laboratory of Forensic Toxicology in the National Institute of Health in Morocco included all positives results in pesticides analysis. Cases were analyzed according to the following criteria: gender, age, origine, poisoning type and class of pesticide. Results: In the period of study, from total of 3104 analysis performed in the laboratory, 130 cases (4.2% were related with fatal pesticides poisoning deaths which were classified as a suicide in 23.1% cases, as an uncertain in 75% and accidental in 1.5%. 51% of cases were related to males and 48% to females. The most represented city was Rabat with 55 cases (42.3%. Insecticides (organophosphorus, organochlorine and carbamates were the most frequent cause of fatal pesticides poisoning (75.2%, followed by aluminum phosphide (21.5%, one case of pyrethroid and one case of coumarinic anticoagulant were found. Conclusion: In spite of the effort made in the rules of pesticides in Morocco, the government must develop a strong system which can attribute to prevent this poisoning. Introduction: Les intoxications aigües par les pesticides sont devenues de plus en plus fréquentes. Elles représentent une importante cause de morbidité et de mortalité à travers le monde. L'objectif de notre travail était de tracer un profil épidémiologique des intoxications mortelles par les pesticides au Maroc sur la période entre 2000 et 2005. Matériel et méthodes : Étude rétrospective recouvrant la période de janvier 2000 à décembre 2005, fondée sur les donnés toxicologiques du laboratoire de Toxicologie à l'Institut National d'Hygiène (Maroc. Les cas ont été analysés selon les critères suivants : sexe, âge, origine, type d'intoxication et classe des pesticides incriminés. Résultats: Sur la période étudiée, parmi les 3104 analyses effectuées au laboratoire, 130 cas (4,2 % sont reliés aux intoxications mortelles aux pesticides ; 23,1 % des intoxications aux pesticides sont volontaires, 75 % sont d'origine indéterminée et seulement 1,5 % sont accidentelles. On retrouve 51 % d'hommes et 48 % de femmes. La ville la plus représentée est Rabat avec 55 cas (42,3 %. Les insecticides (organophosphorés, organochlorés et carbamates sont les plus incriminés dans ces intoxications (75,2 % suivis de phosphure d'aluminium (21,5 %. Un cas d'intoxication aux pyréthrinoïdes et un cas de raticide coumarinique sont retrouvés. Conclusion : Malgré les efforts fournis dans la réglementation des pesticides au Maroc, le gouvernement doit développer en collaboration avec tous les organismes concernés un système puissant pour la prévention de ces intoxications.

Ait El Cadi Mina

2009-01-01

 
 
 
 
181

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 occurred with lannate pesticide treatment

182

An efficient and environmentally friendly method for the synthesis of cellulose carbamate by microwave heating.  

Science.gov (United States)

An efficient, solvent-free, and catalyst-free microwave synthesis of cellulose carbamate from a mixture of native cellulose and urea is reported. The structure of the samples are characterized by elemental analysis, FT-IR spectroscopy, X-ray diffraction, and NMR spectrometry. Cellulose carbamates with a nitrogen content of 0.651-2.427% are obtained by microwave heating at 255?W for 2-5?min. With the introduction of carbamate groups, the hydrogen bonding and crystalline structure of the native cellulose are partially destroyed. The products retain the cellulose I crystalline form of the native cellulose, and display good solubility in NaOH solutions. PMID:21638412

Guo, Yi; Zhou, Jinping; Song, Yongbo; Zhang, Lina

2009-09-01

183

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

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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

184

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

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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

185

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

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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

186

Study of Inhibition, Reactivation and Aging Processes of Pesticides Using Graphene Nanosheets/Gold Nanoparticles-Based Acetylcholinesterase Biosensor  

Energy Technology Data Exchange (ETDEWEB)

Organophosphate (OP) and carbamate pesticides exert their toxicity via attacking the hydroxyl moiety of serine in the 'active site' of acetylcholinesterase (AChE). In this paper we developed a stable AChE biosensor based on self-assembling AChE to graphene nanosheet (GN)-gold nanoparticles (AuNPs) nanocomposite electrode for investigation of inhibition, reactivation and aging processes of different pesticides. It is confirmed that pesticides can inhibit AChE in a short time. OPs poisoning is treatable with oximes while carbarmates exposure is insensitive to oximes. The proposed electrochemical approach thus provides a new simple tool for comparison of pesticide sensitivity and guide of therapeutic intervention.

Zhang, Lin; Long, Linjuan; Zhang, Weiying; Du, Dan; Lin, Yuehe

2012-09-10

187

[Comparison of three different QuEChERS sample treatment methods in the analysis of more than one hundred pesticide residues in tobacco by gas chromatography-tandem mass spectrometry].  

Science.gov (United States)

With a combination of QuEChERS method and gas chromatography-tandem mass spectrometry (GC-MS/MS) technique, three sample treatment methods (solvent exchange method, toluene dilution method, hexane liquid-liquid extraction method) were established to analyse more than one hundred pesticide residues in tobacco. The 155 pesticide analytes contained 58 organophosphorus, 28 organochlorine, 10 pyrethroids, 10 acyl amide, 11 carbamate, 7 dinitroaniline and 31 other family pesticides. Comparison of the three treatment methods was investigated on performances including matrix effect, co-extracted matrix, peak interference, recovery and the limit of quantification (LOQ). The hexane liquid-liquid extraction method gave the cleanest extract but poorer recovery; the solvent exchange and toluene dilution method could guarantee recoveries in the range of 70% and 120% for most of the 155 pesticides. We found that organophosphorus, acyl amide and carbamate pesticides exhibited relative strong matrix effects compared with organochlorine and pyrethroid pesticides. Toluene dilution method was recommended to analyse organophosphorus pesticides, and hexane liquid-liquid extraction (LLE) method was recommended to analyse organochlorine and pyrethroid pesticides. PMID:24558850

Chen, Xiaoshui; Bian, Zhaoyang; Yang, Fei; Liu, Shanshan; Tang, Gangling; Hu, Qingyuan

2013-11-01

188

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

189

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

190

Activation of electrophilicity of stable Y-delocalized carbamate cations in intramolecular aromatic substitution reaction: evidence for formation of diprotonated carbamates leading to generation of isocyanates.  

Science.gov (United States)

Although cations with three heteroatoms, such as monoprotonated guanidine and urea, are stabilized by Y-shaped conjugation and such Y-conjugated cations are sufficiently basic to be further protonated (or protosolvated) to dications in strongly acid media, only O-monoprotonated species have been detected in the case of carbamates even in magic acid. We found that the trifluoromethanesulfonic acid-catalyzed cyclization of arylethylcarbamates proceeds to afford dihydroisoquinolones in high yield. In strong acids, methyl carbamates are fully O-monoprotonated, and these monocations do not undergo cyclization even under heating. But, as the acidity of the reaction medium is further increased, the cyclization reaction of methyl phenethylcarbamates starts to proceed as a first-order reaction, with a linear relationship between rate and acidity. The sign and magnitude of the entropy of activation ?S(‡) were found to be similar to those of other A(Ac)1 reactions. These results strongly support the idea that further protonation of the O-protonated carbamates is involved in the cyclization, but the concentration of the dications is very low and suggests that the rate-determining step is dissociation of methanol from the diprotonated carbamate to generate protonated isocyanate, which reacts with the aromatic ring. Therefore, O-protonated carbamates are weak bases in sharp contrast to other Y-shaped monocations. PMID:23025848

Kurouchi, Hiroaki; Kawamoto, Kyoko; Sugimoto, Hiromichi; Nakamura, Satoshi; Otani, Yuko; Ohwada, Tomohiko

2012-10-19

191

Before the curtain falls: endocrine-active pesticides--a German contamination legacy.  

Science.gov (United States)

The European Parliament recently approved a new EU regulation aimed at eliminating the use of pesticides that have unwanted endocrine-disrupting properties. The test criteria for these chemicals are slated to be finalized by 2013. For this reason, in this review, we have evaluated the meta data of lists and databanks that address pesticides with potentially endocrine-disrupting properties, and have checked which of the 250 active ingredients currently in use in Germany are affected. Azoles, dithio-carbamates/carbamates, and pyrethroids were most frequently rated as endocrine-active ingredients. In Germany, assessments have shown that total environmental pesticide emission is equivalent to approximately 0.1% of total pesticide use.Courtyard drainage and field runoff are regarded to constitute the most important sources of pesticide emission into the aquatic environment. In addition, in several investigations of drinking- and groundwater contamination, various pesticide-active ingredients and their metabolites were confirmed to be contaminants. Water suppliers recorded the following pesticides or their metabolites as being most frequently detected in drinking water: atrazine, desethylatrazine, diuron, simazine, isoproturon,and its dichlobenil metabolite 2,6-dichlorobenzamide. Surface water contamination results mainly from substances that are no longer approved by EU pesticide regulation. The most frequently detected pesticides in streaming waters that are still authorized were bentazone, diuron, glyphosate, isoproturon, MCPA, mecoprop,metamitron, pendimethalin, and tebuconazole. Pesticide residues in comestible goods of herbal origin are periodically detected in all EU member countries. The European Commission recently published results showing that 54% of all monitoring samples were devoid of positive findings. Of samples showing detectable residues, 42% were below, and 4.4% exceeded the EUMRLs. Monitoring data over a 10-year period revealed that the percentage of foodstuff without detectable pesticide residues has continuously decreased from 64 to 51.5%. In Germany, herbal samples mainly contained residues of maneb, iprodion,procymidone and deltamethrin. Notwithstanding these detections, chronic health risk evaluations indicated that there were no violations of ADI values. However,for carbaryl, methomyl, and procymidone, ARfDs were exceeded substantially for intake of grapefruit and bell peppers. As a result, the EU withdrew the methomyl authorization in 2008 and revised procymidone guideline values. PMID:21541850

Schulte-Oehlmann, Ulrike; Oehlmann, Jörg; Keil, Florian

2011-01-01

192

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.

193

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

194

Pesticides and Pregnancy  

Science.gov (United States)

... products that are also considered pesticides, such as cockroach spray, rat poison, or flea collars for pets. ... sprayed over much of the Gulf region to control flies and mosquitoes. Will exposure to pesticides increase ...

195

What Is a Pesticide?  

Science.gov (United States)

... All of these common products are considered pesticides: Cockroach sprays and baits Insect repellents for personal use. ... conventional pesticides in increasing numbers. What about pest control devices? A pest control "device" is any instrument ...

196

Pesticide Instrumental Analysis  

International Nuclear Information System (INIS)

This workshop was the evaluation of the pesticides impact on the vegetable matrix with the purpose to determine the analysis by GC / M S. The working material were lettuce matrix, chard and a mix of green leaves and pesticides.

197

Pesticides poisoning  

International Nuclear Information System (INIS)

Pesticides are chemical toxicants which are used to kill by their toxic actions, the pest organisms, known to incur significant economic losses or threaten human life, his health and that of his domesticated animals. These toxicants are seldom species-specific. The presence of these or their metabolites may scientific be vouched not only in the environment they are used, but in the entire ecosystem, in the subsoil, in the underwater reservoirs and in the food chain of all non-target species including man, his friends i.e. predator and parasite organisms which be uses against the pests, and in his cherished domesticated animals. In the present paper a survey is made of different groups of toxic chemicals generally used to manage pests, in the ecosystem, food chain and tissues and body parts of non-target species including man and the ones dear to him. Toxicology and biochemistry of these toxic materials and their important metabolites are also briefly discussed with special reference to ways and means through which these poison the above non-target species. (author)

198

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

199

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

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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

200

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

 
 
 
 
201

Use of lysimeters for determining pesticide fate in agroecosystems  

International Nuclear Information System (INIS)

A lysimeter system is presented in which 14C labelled pesticides are applied in accordance with agricultural practice. The long term behaviour of pesticides in the soil-plant system can thus be determined under realistic climatic, cropping and soil conditions. In these experiments, pesticides and their metabolites are measured in soil, soil solutions, plants and drainage water over several growing seasons. In addition, a wind tunnel, combined with sensitive analytical methods, allows the determination of pesticide residues, their metabolites and 14CO2 as the mineralization product released into the air. Complementary standardized laboratory experiments yield information on the role of individual processes leading to binding, bioavailability and translocation. Important conclusions are thus obtained for the appropriate practical use of pesticides. As a final step in the validation of the lysimeter, a large scale experiment is in progress to compare lysimeter and field studies, with emphasis placed on the translocation of pesticides in deeper soil layers and groundwater. (author). Abstract only

202

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

203

Pesticides halve bees'  

...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 ...

204

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.

205

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

206

Pesticides and children  

International Nuclear Information System (INIS)

Prevention and control of damage to health, crops, and property by insects, fungi, and noxious weeds are the major goals of pesticide applications. As with use of any biologically active agent, pesticides have unwanted side-effects. In this review, we will examine the thesis that adverse pesticide effects are more likely to occur in children who are at special developmental and behavioral risk. Children's exposures to pesticides in the rural and urban settings and differences in their exposure patterns are discussed. The relative frequency of pesticide poisoning in children is examined. In this connection, most reported acute pesticide poisonings occur in children younger than age 5. The possible epidemiological relationships between parental pesticide use or exposure and the risk of adverse reproductive outcomes and childhood cancer are discussed. The level of consensus among these studies is examined. Current concerns regarding neurobehavioral toxicity and endocrine disruption in juxtaposition to the relative paucity of toxicant mechanism-based studies of children are explored

207

Kinetic and physicochemical properties of brain acetylcholinesterase from the peacock bass (Cichla ocellaris) and in vitro effect of pesticides and metal ions.  

Science.gov (United States)

Brain acetylcholinesterase (AChE; EC 3.1.1.7) from peacock bass (Cichla ocellaris) was characterized and the effect of organophosphorus and carbamate pesticides as well as ions and heavy metals was evaluated. The kinetic parameters K(m) and V(max) were determined as 0.769 mM and 0.189 U/mg of protein respectively. Optimal pH and temperature were found to be 8.0 and 45°C. The enzyme retained approximately half of the activity after incubation at 50°C for 30 min. Total cholinesterase activity on brain of this species can be ascribed to AChE according to selective inhibitors analysis (neostigmine, eserine and BW284c5 reduced its activity whereas no effect was noticed for Iso-OMPA). Seven pesticides (five organophosphates: dichlorvos, diazinon, chlorpyrifos, temephos, tetraethyl pyrophosphate - TEPP and two carbamates: carbaryl and carbofuran) showed inhibitory effects on C. ocellaris AChE. However, the strongest effect was observed with carbofuran (IC(50)=0.21 ?M and K(i)=2.57 × 10(-3) ?M). The following ions (1 mM) showed to inhibit its activity (decrescent order): Hg(2+)>As(3+)>Cu(2+)>Zn(2+). EDTA(2-) did not affect enzyme activity. The present study provides assay conditions and data to suggest this enzyme as in vitro biomarker of organophosphorus and carbamate pesticides in routine environmental screening programs. PMID:23220411

Silva, Kaline Catiely Campos; Assis, Caio Rodrigo Dias; Oliveira, Vagne Melo; Carvalho, Luiz Bezerra; Bezerra, Ranilson Souza

2013-01-15

208

Influence of pesticide regulation on acute poisoning deaths in Sri Lanka  

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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

209

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

210

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  

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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

211

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

212

Lignin is linked to ethyl-carbamate formation in ume (Prunus mume) liqueur.  

Science.gov (United States)

Ethyl carbamate concentrations in oak barrel-aged ume (Prunus mume) liqueurs were measured, and possible explanations for elevated levels were examined. The average concentration was 0.30 mg/L, significantly higher than in ume liqueurs not aged in oak (0.08 mg/L). Oak powder extracts were prepared from both untoasted and toasted oak powder by extraction with aqueous ethanol, and these were used to make ume liqueurs. Relative to a no-oak control, the ethyl carbamate concentrations were 3.8 and 11 times higher in the ume liqueur made with the untoasted and toasted oak powder extracts respectively. The extracts were loaded onto a C18 column, washed with water, and eluted with methanol. The (13)C-NMR spectra for the main constituents of the methanol elution fractions were consistent with those for lignin or fragments thereof. The methanol fractions were added to ume liqueur which was stored for 3 months. Relative to a control, the ethyl carbamate concentrations in the 3-month old liqueurs were found to be 1.2 and 4.6 higher for the untoasted oak-powder and the toasted oak-powder respectively. Ethyl carbamate was formed when lignin was added to a 40% aqueous ethanol solution that contained potassium cyanide. These observations suggest that lignin or fragments thereof promote the formation of ethyl carbamate. PMID:22232267

Hashiguchi, Tomokazu; Izu, Hanae; Sudo, Shigetoshi

2012-01-01

213

Synergism studies with binary mixtures of pyrethroid, carbamate and organophosphate insecticides on Frankliniella occidentalis (Pergande).  

Science.gov (United States)

The major mechanism of resistance to most insecticides in Frankliniella occidentalis (Pergande) is metabolic, piperonyl butoxide (PBO) suppressible, mediated by cytochrome-P450 monooxygenases and conferring cross-resistance among insecticide classes. The efficacy of insecticide mixtures of acrinathrin, methiocarb, formetanate and chlorpyrifos was studied by topical exposure in strains of F. occidentalis selected for resistance to each insecticide. The method consisted in combining increasing concentrations of one insecticide with a constant low rate of the second one as synergist. Acrinathrin activity against F. occidentalis was enhanced by carbamate insecticides, methiocarb being a much better synergist than formetanate. Monooxygenase action on the carbamates would prevent degradation of the pyrethroid, hence providing a level of synergism by competitive substrate inhibition. However, the number of insecticides registered for control of F. occidentalis is very limited, and they are needed for antiresistance strategies such as mosaics and rotations. Therefore, a study was made of the synergist effect of other carbamates not used against thrips, such as carbofuran and carbosulfan, against a susceptible strain and a field strain. Neither carbamate showed synergism to acrinathrin in the susceptible strain, but both did in the field strain, carbosulfan being a better synergist than carbofuran. The data obtained indicate that low rates of carbamates could be used as synergists to restore some pyrethroid susceptibility in F. occidentalis. PMID:17173346

Bielza, Pablo; Espinosa, Pedro J; Quinto, Vicente; Abellán, Jaime; Contreras, Josefina

2007-01-01

214

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

215

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

Energy Technology Data Exchange (ETDEWEB)

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.

Wilde, Tineke de [Laboratory of Crop Protection Chemistry, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, B-9000 Ghent (Belgium)], E-mail: Tineke.DeWilde@UGent.be; Spanoghe, Pieter [Laboratory of Crop Protection Chemistry, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, B-9000 Ghent (Belgium); Mertens, Jan; Sniegowksi, Kristel; Ryckeboer, Jaak [Division of Soil and Water Management, Faculty of Bioscience Engineering, K.U. Leuven, Kasteelpark Arenberg 20, B-3001 Heverlee (Belgium); Jaeken, Peter [PCF-Royal Research Station of Gorsem, De Brede Akker 13, 3800 Sint-Truiden (Belgium); Springael, Dirk [Division of Soil and Water Management, Faculty of Bioscience Engineering, K.U. Leuven, Kasteelpark Arenberg 20, B-3001 Heverlee (Belgium)

2009-04-15

216

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

217

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.

218

Consumer Products Treated with Pesticides  

Science.gov (United States)

Consumer Products Treated with Pesticides Resources Questions On Pesticides? National Pesticide Information Center (NPIC) 1-800-858- ... various items has become of increased concern to consumers. In response to these concerns, many products (e. ...

219

Solid-state-trapped reactive ammonium carbamate self-derivative salts of prolinamide.  

Science.gov (United States)

Single crystals for two polymorphs of the ammonium carbamate self-derivative salt of prolinamide have been successfully obtained and characterized. Decarbonation of the carbamate salts was monitored by calorimetry, confirming stabilization of the reactive carbonated adducts in the solid state. Sublimation of the salts afforded crystals of prolinamide, leading to the first crystal structure of this otherwise common molecule. Reactivity of the ammonium carbamate self-derivative salt is further illustrated by the observation of a series of derived products, including dehydroprolinamide, a methylene-bridged prolinamide, and a bicyclic derivative. Crystal structures of these products display distinct amidic and/or non-amidic hydrogen bonding. This study emphasizes the reactivity of carbonated amines stabilized in the solid and opens perspectives for a systematic study of (solid-state) reactions involving these trapped reactive species. PMID:24551566

Tilborg, Anaëlle; Lanners, Steve; Norberg, Bernadette; Wouters, Johan

2013-12-01

220

Solid-State-Trapped Reactive Ammonium Carbamate Self-Derivative Salts of Prolinamide  

Science.gov (United States)

Single crystals for two polymorphs of the ammonium carbamate self-derivative salt of prolinamide have been successfully obtained and characterized. Decarbonation of the carbamate salts was monitored by calorimetry, confirming stabilization of the reactive carbonated adducts in the solid state. Sublimation of the salts afforded crystals of prolinamide, leading to the first crystal structure of this otherwise common molecule. Reactivity of the ammonium carbamate self-derivative salt is further illustrated by the observation of a series of derived products, including dehydroprolinamide, a methylene-bridged prolinamide, and a bicyclic derivative. Crystal structures of these products display distinct amidic and/or non-amidic hydrogen bonding. This study emphasizes the reactivity of carbonated amines stabilized in the solid and opens perspectives for a systematic study of (solid-state) reactions involving these trapped reactive species. PMID:24551566

Tilborg, Anaëlle; Lanners, Steve; Norberg, Bernadette; Wouters, Johan

2013-01-01

 
 
 
 
221

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

222

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

223

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

224

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

Science.gov (United States)

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 RNA target was observed. PMID:2771642

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

1989-08-11

225

Geostatistics as a basis to the CMLS pesticide simulation model with validation in soil columns Geoestatística como suporte ao modelo de simulação de agrotóxico CMLS com validação em colunas de solos  

Directory of Open Access Journals (Sweden)

Full Text Available The use of simulation models is probably the most efficient means for predicting the behavior of pesticides in the soil-plant-water system. The CMLS (Chemical Movement in Layered Soils simulation model for predicting the fate of pesticides was used for studying the behavior of tebuthiuron, a herbicide used in sugar cane crops, from a sampling grid with 111 sampling points 200 m apart from one another and encompassing three types of soil: Ustic Quartzipsamment, Rhodic Hapludox and Typic Hapludox, all with medium and clay textures. The 373 points assessed by the simulator, generated from samples coming from the original grid and through the geostatistical methods of variography and ordinary kriging, returned the depth values reached by the herbicide after six years of simulation (1989-1995. For the Ustic Quartzipsamment, tebuthiuron, in four simulated points, returned depth values above 43 m and a maximum 50 m, with a certain amount of the product still remaining in the soil that was close to 10% of the original 1.1 kg ha-1 applied. Results from the column assay used for validating the model showed that the model overestimated the depth reached by the herbicide in 6.6% as compared to the column value for the Ustic Quartzipsamment. The depth was underestimated in 4.5% and 20% for the Typic Hapludox and the Rhodic Hapludox, respectively. These data support the adequacy of the model for assessing the fate of tebuthiuron in both Ustic Quartzipsamment and Typic Hapludox.O uso de modelos de simulação é provavelmente a maneira mais eficiente para predizer o comportamento de agrotóxicos no sistema solo/água/planta. O modelo de simulação de destino de agrotóxicos CMLS (Chemical Movement in Layered Soils, foi usado para estudar o comportamento do herbicida tebuthiuron, utilizado na cultura de cana-de-açúcar, a partir de uma grade de amostragem composta de 111 pontos amostrais, equi-espaçados de 200 m e englobando três tipos de solo: Neossolo Quartzarênico (RQ, Latossolo Vermelho distroférrico (LVdf e Latossolo Vermelho distrófico (LVd, texturas média e argilosa. Os 373 pontos avaliados pelo simulador, gerados das amostras da grade original e através dos métodos geoestatísticos da variografia e krigagem, produziram valores de profundidade atingida pelo herbicida, após seis anos de simulação (1989-1995. Para Neossolo Quartzarênico (RQ, o tebuthiuron, em quatro pontos simulados, apresentou valores de profundidade acima de 43 m e com máximo de 50 m, com uma quantidade de produto permanecendo ainda no solo, próximo a 10% do valor aplicado de 1,1 kg ha-1. Resultados provenientes do ensaio em coluna, usados para a validação do modelo, mostraram que o mesmo superestimou em 6,66% a profundidade atingida pelo herbicida quando comparado ao valor produzido pela coluna, para o Neossolo Quartzarênico (RQ, e subestimou com valores de 4,5% e 20,0%, para o Latossolo Vermelho distrófico (LVd e o Latossolo Vermelho-distroférrico (LVdf, respectivamente. Esses dados confirmam, para o Neossolo Quartzarênico(RQ e o Latossolo Vermelho-distrófico (LVd a adequação do modelo, na avaliação do destino do herbicida.

Gilberto Nicolella

2005-01-01

226

Geostatistics as a basis to the CMLS pesticide simulation model with validation in soil columns / Geoestatística como suporte ao modelo de simulação de agrotóxico CMLS com validação em colunas de solos  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese O uso de modelos de simulação é provavelmente a maneira mais eficiente para predizer o comportamento de agrotóxicos no sistema solo/água/planta. O modelo de simulação de destino de agrotóxicos CMLS (Chemical Movement in Layered Soils), foi usado para estudar o comportamento do herbicida tebuthiuron, [...] utilizado na cultura de cana-de-açúcar, a partir de uma grade de amostragem composta de 111 pontos amostrais, equi-espaçados de 200 m e englobando três tipos de solo: Neossolo Quartzarênico (RQ), Latossolo Vermelho distroférrico (LVdf) e Latossolo Vermelho distrófico (LVd), texturas média e argilosa. Os 373 pontos avaliados pelo simulador, gerados das amostras da grade original e através dos métodos geoestatísticos da variografia e krigagem, produziram valores de profundidade atingida pelo herbicida, após seis anos de simulação (1989-1995). Para Neossolo Quartzarênico (RQ), o tebuthiuron, em quatro pontos simulados, apresentou valores de profundidade acima de 43 m e com máximo de 50 m, com uma quantidade de produto permanecendo ainda no solo, próximo a 10% do valor aplicado de 1,1 kg ha-1. Resultados provenientes do ensaio em coluna, usados para a validação do modelo, mostraram que o mesmo superestimou em 6,66% a profundidade atingida pelo herbicida quando comparado ao valor produzido pela coluna, para o Neossolo Quartzarênico (RQ), e subestimou com valores de 4,5% e 20,0%, para o Latossolo Vermelho distrófico (LVd) e o Latossolo Vermelho-distroférrico (LVdf), respectivamente. Esses dados confirmam, para o Neossolo Quartzarênico(RQ) e o Latossolo Vermelho-distrófico (LVd) a adequação do modelo, na avaliação do destino do herbicida. Abstract in english The use of simulation models is probably the most efficient means for predicting the behavior of pesticides in the soil-plant-water system. The CMLS (Chemical Movement in Layered Soils) simulation model for predicting the fate of pesticides was used for studying the behavior of tebuthiuron, a herbic [...] ide used in sugar cane crops, from a sampling grid with 111 sampling points 200 m apart from one another and encompassing three types of soil: Ustic Quartzipsamment, Rhodic Hapludox and Typic Hapludox, all with medium and clay textures. The 373 points assessed by the simulator, generated from samples coming from the original grid and through the geostatistical methods of variography and ordinary kriging, returned the depth values reached by the herbicide after six years of simulation (1989-1995). For the Ustic Quartzipsamment, tebuthiuron, in four simulated points, returned depth values above 43 m and a maximum 50 m, with a certain amount of the product still remaining in the soil that was close to 10% of the original 1.1 kg ha-1 applied. Results from the column assay used for validating the model showed that the model overestimated the depth reached by the herbicide in 6.6% as compared to the column value for the Ustic Quartzipsamment. The depth was underestimated in 4.5% and 20% for the Typic Hapludox and the Rhodic Hapludox, respectively. These data support the adequacy of the model for assessing the fate of tebuthiuron in both Ustic Quartzipsamment and Typic Hapludox.

Gilberto, Nicolella; Archimedes, Perez Filho; Manoel Dornelas de, Souza; Vera Lúcia, Ferracini.

227

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 (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.

228

Trifluoroacetic acid-promoted Michael addition-cyclization reactions of vinylogous carbamates.  

Science.gov (United States)

A simple and efficient methodology has been developed for the synthesis of pyrrolobenzoxazine and 3-arylamino coumarin derivatives promoted by trifluoroacetic acid. The initial step in the current protocol involves a Michael addition of the 1,4-benzoxazinone derivatives, a novel class of vinylogous carbamates to the Michael acceptors and subsequent cyclization. PMID:24756460

Naganaboina, Ram Tilak; Nayak, Amrita; Peddinti, Rama Krishna

2014-06-01

229

Substrate scope and stereocontrol in the Rh(II)-catalysed oxyamination of allylic carbamates  

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Application of a modified Du Bois protocol for rhodium-stabilised nitrenoid generation to a variety of allylic carbamates results in 4-acetoxymethyl-1,3-oxazolidin-2-one derivatives with moderate to high levels of stereocontrol. © 2014 Elsevier Ltd. All rights reserved.

Unsworth, Wp; Lamont, Sg; Robertson, J.

2014-01-01

230

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

International Nuclear Information System (INIS)

ry. 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.

231

76 FR 34147 - Land Disposal Restrictions: Revision of the Treatment Standards for Carbamate Wastes  

Science.gov (United States)

...and decantates) from the production of carbamates and carbamoyl oximes. Acetophenone...... 98-86-2 0.010 9.7 Aniline........... 62-53-3 0.81 14 Benomyl \\10\\...... 17804-35-2 0.056; or CMBST, 1.4; or...

2011-06-13

232

A new group of oxime carbamates as reversible inhibitors of fatty acid amide hydrolase.  

Science.gov (United States)

A series of oxime carbamates have been identified as potent inhibitors of fatty acid amide hydrolase (FAAH), an important regulatory enzyme of the endocannabinoid signaling system. Kinetic analysis indicates that they behave as non-competitive, reversible inhibitors, and show remarkable selectivity for FAAH over the other components of the endocannabinoid system. PMID:20591666

Gattinoni, Sonia; Simone, Chiara De; Dallavalle, Sabrina; Fezza, Filomena; Nannei, Raffaella; Battista, Natalia; Minetti, Patrizia; Quattrociocchi, Gianandrea; Caprioli, Antonio; Borsini, Franco; Cabri, Walter; Penco, Sergio; Merlini, Lucio; Maccarrone, Mauro

2010-08-01

233

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...

234

Effect Of Fenugreek Seed Powder In Toxicity Induced By MALAPHOS And METHAVINE Pesticides In Male Rats  

International Nuclear Information System (INIS)

Pesticides administration to rats led to an enhancement in oxidative stress and generation of free radicals. These free radicals may be involved in the toxicity of some pesticides. Therefore, the present study was undertaken to assess the effect of pre-treatment of rats with fenugreek seed powder at the dose level of 250 mg/kg b.wt in inhibiting the oxidative damage induced by administration malaphos (organophosphorus) at the dose level of 343.75 mg/kg b.wt and methavine (carbamate) at the dose level of 4 mg/kg b.wt for 6 weeks. Also the present study was carried out to evaluate the strength of fenugreek seed powder and the influence of both pesticides, malaphos and methovine on serum glucose, insuline, total bilirubin, total protein, albumin and gamma glutamyl transferase (?GT), calcium (Ca), inorganic phosphorus and iron (Fe) contents. The metabolism of14C-glucose injected 24 hours post-treatments with the two pesticides and fenugreek seed powder were studied. The results obtained demonstrated that the deleterious damage due to malaphos and methavine administration was manifested by the significant elevation in serum glucose, gamma glutamyl transferase (? -GT), calcium (Ca), and iron content. Also, there was significant decrease in insulin level, total bilirubin, total protein, albumin and inorganic phosphorus. On the other hand, the data recorded a reduction in the tracing of metabolizable of14C- glucose which was more pronounced in urine ofse which was more pronounced in urine of rats administrated malaphos compared to those received methavine pesticide. It could be concluded that administration of fenugreek seed powder (FSP) to rats during the treatment with malaphos or methavine pesticide attenuated to a great extent the damaging effects of both pesticides on the here in assayed parameters. According, by fenugreek administration at the used dose may have an indirect physiological effect on the metabolism of14C- glucose.

235

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

236

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

Directory of Open Access Journals (Sweden)

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

237

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

Science.gov (United States)

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. PMID:19144454

De Wilde, Tineke; Spanoghe, Pieter; Mertens, Jan; Sniegowksi, Kristel; Ryckeboer, Jaak; Jaeken, Peter; Springael, Dirk

2009-04-01

238

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.

239

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

240

Pesticides: Emergency Information  

Science.gov (United States)

... being treated. Do not use eye drops or chemicals or drugs in the wash water. Poison on skin. If pesticide splashes on the skin, drench area with water and remove contaminated clothing. Wash skin and hair thoroughly with soap and ...

 
 
 
 
241

Pesticide Safety Tips  

Science.gov (United States)

... minutes. Do not use eye drops or place chemicals or drugs in the wash water. Poison on skin. If pesticide splashes on the skin, drench area with water and remove contaminated clothing. Wash skin and hair thoroughly with soap and ...

242

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 Products for ... clear directions and safety warnings. Common Illegal Pest Products mothballs | pet products | insecticidal chalk | " Tres Pasitos " | antibacterial ...

243

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

244

Survey of pesticide residues in maize, cowpea and millet from northern Cameroon: part I.  

Science.gov (United States)

In northern Cameroon, the misuse of pesticides for pest control is common among small-scale farmers. Therefore, monitoring of pesticide residues was carried out on stored maize, cowpea and millet from eight localities. The determination of residues of organochlorines (lindane, ?-endosulfan and ?-endosulfan), organophosphorus compounds (malathion and pirimiphos-methyl), synthetic pyrethroids (permethrin) and carbamates (carbufuran) was performed using GC-ECD/NPD and GC-MS for confirmation. Organochlorine pesticides were detected more frequently and in higher concentrations, ranging from 0.02 ± 0.01 mg kg(-1) for ?-endosulfan in millet to 9.53 ± 4.00 mg kg(-1) lindane in maize, than organophosphorus compounds, with concentrations varying from 0.04 ± 0.03 mg kg(-1) for pirimiphos methyl to 0.23 ± 0.38 mg kg(-1) for malathion in maize. Permethrin was found only in maize at 0.39 ± 0.23 mg kg(-1). No carbofuran was found. More than 75% of samples contained pesticide residues above the maximum residue limit (MRL); showing a potential human dietary risk related to consumption of these grains. PMID:24779572

Sonchieu, Jean; Benoit Ngassoum, Martin; Bosco Tchatchueng, Jean; Srivastava, Ashutosh Kumar; Srivastava, Laxman Prasad

2010-01-01

245

pesticides workshop presentation niea jake gibson  

...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...Principally occupied by agriculture Mineral Extraction Sites Mixed Forest Moors and...

246

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)

247

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

248

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.

249

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

250

The concentration of ethyl carbamate in commercial ume (Prunus mume) liqueur products and a method of reducing it.  

Science.gov (United States)

The ethyl carbamate concentration of commercial ume liqueur products was studied, and a method of reducing it was examined from the viewpoint of antioxidation. The average ethyl carbamate concentration across 38 ume liqueur products was 0.12 mg/l (0.02-0.33 mg/l). When potassium metabisulfite was added to a concentration of 0-1,000 ppm during production, the generation of ethyl carbamate was reduced in a concentration-dependent manner, but when the amount of potassium metabisulfite added was below the maximum level allowed under the Japanese Food Sanitation Act, the reduction was only 27%. When ume liqueurs were produced under deoxygenated conditions created using an oxygen absorber, the ethyl carbamate concentration was reduced by up to 47% as compared with the control group, probably due mainly to a reduction in free hydrogen cyanide. When ume liqueur was produced in an oxygen atmosphere, the ethyl carbamate concentration increased by up to 50% as compared with the control group. Thus, oxygen may be involved in the generation of ethyl carbamate in ume liqueur production. PMID:20944415

Hashiguchi, Tomokazu; Horii, Sachie; Izu, Hanae; Sudo, Shigetoshi

2010-01-01

251

Pesticides in the agricultural environment  

International Nuclear Information System (INIS)

In most countries, regulations to control the use of pesticides require data from a hierarchical series of tests in order to assess their environmental acceptability. The test sequence begins with laboratory measurements, which are followed by field studies intended to confirm the predictions made from the laboratory results. Frequently, such predictions are not confirmed, largely because controlled laboratory conditions are too far removed from those that occur in the field. There is increasing interest in the potential of lysimeter systems to replace many of the laboratory tests. They enable test, including those using radiolabelled compounds, to be conducted outdoors under closely monitored conditions. The results to data are encouraging, but more work is required to validate such systems. (author). 33 refs

252

The Lasting Threat of Pesticides  

Science.gov (United States)

Over the past several weeks, a plethora of news articles have featured pesticides: the recent findings that amniotic fluids (which surround a fetus in the womb) contain detectable levels of pesticides in 30% of tested women; the fact that, in addition to the already-established link to cancers, pesticide exposure during pregnancy may also be linked to child learning disabilities, such as Hyperactivity or Attention Deficit Disorder; and the initiation of a multi-agency proposal to impose a sales tax on agricultural chemicals, such as pesticides and insecticides. Despite continued controversy over the real health effects of pesticides, few argue about the global increase in pesticide use. With the increase in pesticide use, there is a concomitant increase in the amount of unused, stored (or more accurately, abandoned) pesticides. This week's In The News addresses the fate of unused pesticides -- the several hundred thousand tons of obsolete, dangerous pesticides that currently plague several countries around the globe. Many of these obsolete pesticides were banned from use after import, were oversupplied or sent as duplicate supplies by aid agencies, or were inappropriate for local use. The nine resources listed provide background information and scientific resources on pesticides and the obsolete pesticide problem.

Payne, Laura X.

253

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

254

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

255

Quantitative analysis of ethyl carbamate in Korean alcoholic beverages by chromatography with mass selective detection  

Energy Technology Data Exchange (ETDEWEB)

In order to determine the contents of ethyl carbamate in Korean traditional alcoholic beverages and general beverages, GC/MS-SIM method was used after extraction of beverages with dichloromethane. The contents of ethyl carbamate in Korean traditional alcoholic beverages, non-distilled alcohol, and whisky were detected in the rage of 4.6-50.2 {mu}g/L, 27.8-45.4 {mu}g/L, and 24.8-55.1 {mu}g/L, respectively. The recoveries were ranged from 83.3 to 104.8 %. The values of relative standard deviation were ranged from 1.8 to 14.8% and the detection limit was 0.3 {mu}g/L. (author). 13 refs., 2 tabs., 4 figs.

Park, G.B.; Lee, S.G. [Korea Research Institute of Chemical Technology, Taejon (Korea)

2002-02-01

256

Effects of pesticides on songbird productivity in conjunction with pecan cultivation in southern Georgia: A multiple-exposure experimental design  

Science.gov (United States)

A prototypic experimental design was used to assess sublethal effects of multiple and varied organophosphates and carbamates on reproduction in birds. The design allowed for classification of pesticide exposure according to toxicity of applied compounds and type and frequency of applications. Daily survival rates (DSRs) of nests, eggs, and nestlings were determined for northern mockingbirds (Mimus polyglottos), brown thrashers (Toxostoma rufum), and northern cardinals (Cardinalis cardinalis) nesting along edges of pecan orchards and row crops in southern Georgia [USA]. Egg and nestling DSRs for all species combined varied inversely (P 0.05) among three exposure levels. Brain cholinesterase activities were age-dependent and substantiated adult, but not nestling, exposure. Results suggest that increasing exposure to pesticides may reduce songbird productivity.

Patnode, K.A.; White, D.H.

1991-01-01

257

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)

258

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

259

Structural and ultrastructural study of the rabbit testes exposed to carbamate insecticide.  

Science.gov (United States)

The present study was conducted to investigate the impact of carbamate insecticide - bendiocarb on the testicular structure of adult rabbits. Bendiocarb was perorally administered daily for 10 and 30 days, at a dose 5 mg/kg of body weight. After the histological sampling the tissues were investigated and compared with control. After the bendiocarb administration the absolute and relative testicular weight decreased significantly (P bendiocarb on structure of rabbit testes. PMID:22540657

Almasiova, Viera; Holovska, Katarina; Tarabova, Lucia; Cigankova, Viera; Lukacinova, Agnesa; Nistiar, Frantisek

2012-01-01

260

The use of yeast inoculation in fermentation for port production; effect on total potential ethyl carbamate  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A commercial wine yeast Saccharomyces cerevisiae UCD 522 (pre-cultured in the presence of certain mass-labelled amino acids) was inoculated into a port must which was then allowed to ferment under controlled conditions of temperature and agitation. The influence of potential ethyl carbamate (EC) precursor formed due to yeast pre-culture, upon total potential EC levels was studied at various stages of fermentation. Pre-culture accumulation did not give rise to detectable levels of EC precurs...

Watkins, S. J.; Hogg, T. A.; Lewis, M. J.

1996-01-01

 
 
 
 
261

New Ultra Small Iron-Oxide Nanoparticles with Titanium-Carbamate Coating: Preparation and Magnetic Properties  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

262

Biochemical basis of organophosphate and carbamate resistance in Asian citrus psyllid.  

Science.gov (United States)

The Asian citrus psyllid, Diaphorina citri Kuwayama, is a worldwide pest of citrus, which vectors the putative causal pathogen of huanglongbing. Current management practices warrant continuous monitoring of field populations for insecticide resistance. Baseline activities of acetylcholinesterase (AChE), general esterase, and glutathione S-transferase as well as sensitivity of AChE to selected organophosphate and carbamate insecticides were established for a susceptible laboratory strain (Lab) and compared with several field populations of D. citri from Florida. The specific activity of AChE in various D. citri populations ranged from 0.77 to 1.29 microM min(-1) mg of protein(-1); the Lab strain was characterized by the highest activity. Although reduced AChE sensitivity was observed in the Lab strain compared with field populations, overlap of 95% confidence intervals of I50 values (concentration required for 50% AChE activity inhibition) suggests no significant difference in AChE sensitivity among all populations tested for a given insecticide. There was no significant evidence of target site insensitivity in field populations that were exposed to the selected organophosphate and carbamate insecticides tested. The specific activity of general esterase and glutathione S-transferase was lowest in the Lab strain and was generally comparable to that of the field populations evaluated. The current data provide a mode-of-action specific baseline for future monitoring of resistance to organophosphate and carbamate insecticides in populations of D. citri. PMID:22606825

Tiwari, Siddharth; Stelinski, Lukasz L; Rogers, Michael E

2012-04-01

263

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

264

Inhibitory effects of four carbamate insecticides on acetylcholinesterase of male and female Carassius auratus in vitro.  

Science.gov (United States)

The inhibitory effects of four carbamate insecticides, methomyl, thiodicarb, carbofuran and carbosulfan, on acetylcholinesterase of male and female Carassius auratus were investigated in the laboratory. Kinetic constants, biomolecular rate constant (k(i)), carbamylation rate constant (k2) and decarbamylation rate constant (k3) were determined in vitro. The ratios of bimolecular rate constant (female/male) for AChE reacting with methomyl, thiodicarb, carbofuran and carbosulfan were 1.03, 2.44, 1.03 and 1.106, respectively. The k(i) of AChE for thiodicarb was significantly higher in female fish than in male fish (Pcarbosulfan were 1.18, 4.29, 3.53, and 2.07, respectively. The k2 values of AChE for the above four carbamates were significantly higher in females than in males. The ratios of the decarbamylation rate constant (female/male) for methomyl, thiodicarb, carbofuran and carbosulfan were 1.02, 1.39, 1.06, and 1.98, respectively. Only for carbosulfan, the decarbamylation rate of AChE was significantly higher in the female than in the male, indicating that AChE of females inhibited by carbosulfan recovered more quickly than that of males. The above results suggest that the female in the sensitivity of AChE to carbamates was different from the male fish. PMID:16461013

Yi, M Q; Liu, H X; Shi, X Y; Liang, P; Gao, X W

2006-05-01

265

Distribution of organophosphate and carbamate resistance in Culex pipiens quinquefasciatus (Diptera: Culicidae) in West Africa.  

Science.gov (United States)

The distribution of organophosphate and carbamate resistance was investigated in 33 samples of Culex pipiens quinquefasciatus Say from 25 cities in Côte d'Ivoire and Burkina Faso. Organophosphate resistance levels were higher in Côte d'Ivoire than in Burkina Faso. Chlorpyrifos resistance ratios at LC95 ranged from 4 to 30 times in Côte d'Ivoire and from 3 to 6 times in Burkina Faso. For temephos, ratios ranged from 3 to 18 and from 1 to 2, respectively. Of 27 samples from Côte d'Ivoire, 25 also displayed cross resistance to carbamates as shown by a mortality plateau in bioassays with propoxur and carbosulfan (similar to chlorpyrifos). Cross resistance to organophosphates and carbamates was caused by an insensitive acetylcholinesterase allele (AceR). This gene was absent from Burkina Faso, except in Niangoloko near the Côte d'Ivoire border. Organophosphate resistance also was associated with the presence of A2-B2 overproduced esterases which had higher frequencies in Côte d'Ivoire (75-100%) than in Burkina Faso (40-50%). Two other esterases with the same electrophoretic mobility as C2 from Puerto Rico and B1 from California were identified for the 1st time in West Africa. "C2" was widespread, whereas "B1" was present in only a few mosquitoes from Côte d'Ivoire. These differences in resistance patterns should be taken into consideration in planning urban mosquito control strategies within 2 countries. PMID:9439121

Chandre, F; Darriet, F; Doannio, J M; Rivière, F; Pasteur, N; Guillet, P

1997-11-01

266

Synthesis of esters of aliphatic and aromatic carbamic acids. A comparative study of properties and local anesthetic activity of these compounds.  

Science.gov (United States)

Four basic esters of cyclohexancarbamic acid and their salts with hydrochloride were synthesized and evaluated for local anesthetic activity. It was found that also aliphatic carbamates studied exhibit local anesthetic activity comparable with the activity of analogous esters of aromatic (2-methoxyphenyl) carbamic acid. Our comparative investigation shows that the presence of aromatic group in the ester of carbamic acid influences local anesthetic activity, however the occurrence of aromatic moiety is not necessary condition for their activity. PMID:7576444

Gregán, F; Remko, M; R?canská, E; Csölei, J

1995-09-01

267

Pesticide Use and Water Quality.  

Science.gov (United States)

This publication describes in nontechnical language the problem of pesticide use and how it affects water quality. It provides information on laws affecting pesticide use and the reasons for them, as well as giving directions for the proper use of pesticides. The booklet is divided into five chapters, each of which concludes with a list of study…

Reneau, Fred

268

Ab Initio Investigation of Hydrogen Bonding by Carbamates. Complexes including N-methyl methylcarbamate, N-phenyl methylcarbamate, dimethyl ether, and methyl acetate  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

269

Simultaneous determination of 103 pesticide residues in tea samples by LC-MS/MS.  

Science.gov (United States)

A simple and sensitive method was developed and validated for the simultaneous determination of 103 pesticide residues in tea by LC-MS/MS. For the analysis of the pesticide with polarity, thermal lability or low volatility, this LC-MS/MS method has an advantage over GC. In this work, residual pesticides were extracted from the tea sample with ACN and then purified using Carb-NH(2) SPE cartridges. Using the multiple reaction monitoring mode, the pesticides were quantified and identified by the most abundant and characteristic fragment ions. The recoveries obtained for each pesticide ranged between 65 and 114% at three spiked concentration levels. The intra-day precisions were lower than 19.6%. Good linear relationships were observed with the correlation coefficients r(2) >0.996 for all analytes. The established method was successfully applied to the determination of pesticide residues in real tea samples. PMID:19399859

Huang, Zhiqiang; Zhang, Ying; Wang, Libing; Ding, Li; Wang, Meilin; Yan, Hongfei; Li, Yongjun; Zhu, Shaohua

2009-05-01

270

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

271

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.

272

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

273

Integrating Landsat and California pesticide exposure estimation at aggregated analysis scales: Accuracy assessment of rurality  

Science.gov (United States)

Pesticide exposure estimation in epidemiologic studies can be constrained to analysis scales commonly available for cancer data - census tracts and ZIP codes. Research goals included (1) demonstrating the feasibility of modifying an existing geographic information system (GIS) pesticide exposure method using California Pesticide Use Reports (PURs) and land use surveys to incorporate Landsat remote sensing and to accommodate aggregated analysis scales, and (2) assessing the accuracy of two rurality metrics (quality of geographic area being rural), Rural-Urban Commuting Area (RUCA) codes and the U.S. Census Bureau urban-rural system, as surrogates for pesticide exposure when compared to the GIS gold standard. Segments, derived from 1985 Landsat NDVI images, were classified using a crop signature library (CSL) created from 1990 Landsat NDVI images via a sum of squared differences (SSD) measure. Organochlorine, organophosphate, and carbamate Kern County PUR applications (1974-1990) were matched to crop fields using a modified three-tier approach. Annual pesticide application rates (lb/ac), and sensitivity and specificity of each rurality metric were calculated. The CSL (75 land use classes) classified 19,752 segments [median SSD 0.06 NDVI]. Of the 148,671 PUR records included in the analysis, Landsat contributed 3,750 (2.5%) additional tier matches. ZIP Code Tabulation Area (ZCTA) rates ranged between 0 and 1.36 lb/ac and census tract rates between 0 and 1.57 lb/ac. Rurality was a mediocre pesticide exposure surrogate; higher rates were observed among urban areal units. ZCTA-level RUCA codes offered greater specificity (39.1-60%) and sensitivity (25-42.9%). The U.S. Census Bureau metric offered greater specificity (92.9-97.5%) at the census tract level; sensitivity was low (?6%). The feasibility of incorporating Landsat into a modified three-tier GIS approach was demonstrated. Rurality accuracy is affected by rurality metric, areal aggregation, pesticide chemical class, and pesticide exposure cutoff. Future research should explore integrating Landsat for higher spatial resolution pesticide exposure estimation.

Vopham, Trang Minh

274

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

275

19F nuclear magnetic resonance analysis of the carbamate reaction of alpha-fluoro-beta-alanine (FBAL), the major catabolite of fluoropyrimidines. Application to FBAL carbamate determination in body fluids of patients treated with 5'-deoxy-5-fluorouridine  

International Nuclear Information System (INIS)

alpha-Fluoro-beta-alanine (FBAL), the major catabolite of the antineoplastic fluoropyrimidines, is an amino acid which is in equilibrium with its carbamate derivative in weakly alkaline aqueous solutions containing carbonate. In both water and control biological fluids (urine, plasma) spiked with FBAL (and sodium bicarbonate, in some cases), 19F NMR was used: (i) to determine the pH range over which FBAL carbamate is present (pH greater than or equal to 7), the maximum concentration formed occurring around pH 9, (ii) to show that the amino group of FBAL interacts very slowly with a non-protein plasma component to form a compound X, unstable in acid medium. The presumed structure of X is RCONHCH2CHFCOOH, with R different from an alkyl group but still unidentified. The behavior of FBAL in urine and plasma of rats treated with FBAL or 5'-deoxy-5-fluorouridine (5'-dFUrd), a prodrug of 5-fluorouracil, and from patients treated with 5'-dFUrd was investigated. FBAL carbamate was not present in acid medium and was therefore absent in acidic human urine. However, it was found in alkaline rat urine. FBAL carbamate was found in plasma along with the compound X. The 19F NMR spectra of FBAL and derivatives are complex since alpha-fluoro-beta-ureido-propionic acid, the precursor of FBAL in the catabolic pathway of antineoplastic fluoropyrimidines, produces a signal overlapping that of FBAL carbamate, and very close to that of compound X

276

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.

277

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

Science.gov (United States)

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??-10?? 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. PMID:21115097

Kojima, Hiroyuki; Sata, Fumihiro; Takeuchi, Shinji; Sueyoshi, Tatsuya; Nagai, Tadanori

2011-02-27

278

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...

279

Genotoxic effects of pesticides.  

Science.gov (United States)

Epidemiologic data showed an increase in the number of cancer cases in persons involved in agricultural production using pesticides. According to IARC, more than 25% of pesticides are classified as oncogens. In recent years, the concept of malignant tumors developing after environmental contamination with chemicals has been accepted. Changes in genetic material are at the basis of this process because many environmental pollutants are chemical carcinogens and mutagens with the capacity of causing DNA damage. DNA damage was proposed as a useful parameter for assessing the genotoxic properties of environmental pollutants. The correlation between exposure to carcinogenic substance and the level of DNA damage is essential. Pesticides are highly biologically active chemicals. They may interact with DNA and damage its structure. Such interaction may be critical for the manifestation of carcinogenic properties of different chemicals. We report on the organotropic genotoxic effects of different chemical classes of pesticides (decis, cypermetrin, 2,4-D, polyram) studied by means of alkaline unwinding assay DNA. PMID:9216788

Kornuta, N; Bagley, E; Nedopitanskaya, N

1996-01-01

280

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

 
 
 
 
281

Determination of ethyl carbamate in distilled alcoholic beverages by gas chromatography with flame ionization or mass spectrometric detection.  

Science.gov (United States)

Quantitative methods are detailed for determination of ethyl carbamate in distilled alcoholic beverages by capillary gas chromatography with flame ionization detection (GC/FID) and by packed-column gas chromatography/mass spectrometry (GC/MS) using selected ion monitoring. Five g samples of distillate of known ethanol concentration are diluted with water to 25% ethanol (v/v), washed with petroleum ether, and extracted with dichloromethane prior to GC/FID or GC/MS analysis. As necessary, sample extracts that exhibit GC/FID interference are passed through alumina for additional cleanup. When internal standards (tert-butyl carbamate and n-butyl carbamate for GC/FID, or ethyl 13C-15N-carbamate for GC/MS) were used for quantitation, the limit of detection for ethyl carbamate was in the range of 5-25 ppb. Coefficients of variation ranged from 3.5 to 6.0% for GC/FID determinations, and from 1.4 to 3.2% for GC/MS. Correlation between methods for 22 random distillate samples ranging in concentration from approximately 40 to 800 ppb gave a correlation coefficient (r) of 0.996. PMID:3417601

Pierce, W M; Clark, A O; Hurst, H E

1988-01-01

282

Effects of the carbamates fenoxycarb, propamocarb and propoxur on energy supply, glucose utilization and SH-groups in neurons.  

Science.gov (United States)

Carbamates belonged to an older insecticide group, with propoxur being representative of this group. However, today carbamates with hormonal effects on insects, like fenoxycarb, or with fungicide properties, like propamocarb, are also used. The goal was a comparison of three structurally and functional different carbamates with a possibly common toxicological mechanism. Primary neuronal cell cultures of the rat are a well established model to identify neurotoxic compounds like n-hexane or acrylamide. In this cell culture model endpoints such as viability, energy supply, glucose consumption, glutathione (GSH) levels and cytoskeleton elements were determined. Added to cultured rat cortical neurons for 1 week, fenoxycarb, propamocarb and propoxur considerably decreased ATP levels, mitochondrial membrane potential and glucose consumption. Besides this, fenoxycarb and propamocarb had an impact on neurofilaments. After recovery for 1 week, propoxur also showed effects on neurofilaments, whereas with the other carbamates no tendency for a recovery was seen. These effects were prevented completely by pyruvate for propoxur and propamocarb, and partly so for fenoxycarb. In contrast to the main experimental design, GSH was determined after 1-h treatment with the test substances. Surprisingly, the compounds had only slight or no effect on the GSH level within this time. Further mechanistic studies indicated that carbamates primarily interacted with SH-groups, most likely by interfering with glycolysis and the construction of fibrillary proteins like neurofilaments. The prevention by pyruvate and acetylcysteine pointed to these biochemical endpoints. PMID:14985943

Schmuck, Gabriele; Mihail, Florin

2004-06-01

283

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

284

Biochemical biomarkers in Scinax fuscovarius tadpoles exposed to a commercial formulation of the pesticide fipronil.  

Science.gov (United States)

One of the main pesticides used in the cultivation of sugarcane in São Paulo State, Brazil, is Regent(®)800WG, the main active compound of which is fipronil. Fipronil is a potent insecticide that eliminates pests, including insects resistant to pyrethroids, organophosphates (OP) and carbamates (CA). There is little known on the toxic effects of fipronil on non-target organisms, such as tadpoles of frogs. It is possible that this compound carries a high toxicity for these organisms, since the pesticide can be incorporated into aquatic environments during the rainy season, a time which coincides with the time of amphibian reproduction and the occurrence of tadpoles in the aquatic environment in this region. Thus, the pesticide could be contributing to the decline of amphibians in the northwest region of São Paulo state due to its wide use. This study aimed to test the influence of Regent(®)800WG on some biochemical systems of tadpoles (such as antioxidant defense systems) at different stages of development. The results of analysis from in vivo exposures demonstrated that only a few parameters in the groups exposed to fipronil responded to exposure to Regent(®)800WG, results which indicate that the pesticide instigates biochemical responses in tadpoles. Although catalase and glucose-6-phosphate dehydrogenase (G6PDH) were unchanged during the experiments, glutathione-S-transferase (GST) was inhibited in tadpoles, and the activity of glutathione reductase (GR) varied according to the exposure period and pesticide concentration. This data demonstrated the influence of the fipronil formulation on the metabolism of tadpoles, and showed that it can increase their susceptibility to environmental contaminants. PMID:23489839

Stefani Margarido, Tatiana Cristina; Felício, Andréia Arantes; de Cerqueira Rossa-Feres, Denise; de Almeida, Eduardo Alves

2013-10-01

285

Distributions of pesticides and organic contaminants between water and suspended sediment, San Francisco Bay, California  

Science.gov (United States)

Suspended-sediment and water samples were collected from San Francisco Bay in 1991 during low river discharge and after spring rains. All samples were analyzed for organophosphate, carbamate, and organochlorine pesticides; petroleum hydrocarbons; biomarkers; and polynuclear aromatic hydrocarbons. The objectives were to determine the concentrations of these contaminants in water and suspended sediment during two different hydrologic conditions and to determine partition coefficients of the contaminants between water and sediment. Concentrations of hydrophobic contaminants, such as polynuclear aromatic hydrocarbons, varied with location of sample collection, riverine discharge, and tidal cycle. Concentrations of hydrophobic contaminants in suspended sediments were highest during low river discharge but became diluted as agricultural soils entered the bay after spring rains. Polynuclear aromatic hydrocarbons defined as dissolved in the water column were not detected. The concentrations sorbed on suspended sediments were variable and were dependent on sediment transport patterns in the bay. In contrast, the relatively hydrophilic organophosphate pesticides, such as chlorpyrifos and diazinon, has a more uniform concentration in suspended sediment. These pesticides were detected only after spring rains. Most of the measured diazinon, at least 98% for all samples, was in the dissolved phase. Measured partition coefficients for diazinon generally were uniform, which suggests that suspended-sediment concentrations were close to equilibrium with dissolved concentrations. The concentration of diazinon sorbed to suspended sediments, at any given sampling site, was driven primarily by the more abundant solution concentration. The concentrations of diazinon sorbed to suspended sediments, therefore, were independent of the patterns of sediment movement. ?? 1993 Estuarine Research Federation.

Domagalski, J.L.; Kuivila, K.M.

1993-01-01

286

Tissue concentrations of pesticides, PCBs and metals among ospreys, Pandion haliaetus, collected in France.  

Science.gov (United States)

In this study, osprey (Pandion haliaetus) tissues collected in France were used for contaminants analyses by a non-invasive approach. 53 pesticides (organochlorine, organophosphate, carbamate, pyrethroids, herbicides, anticoagulant rodenticides), 13 PCBs, and 5 metals (mercury, lead, cadmium, copper and arsenic) were quantified in liver of 14 individual samples. PCBs and mercury were frequent (mean 0.5 mg/kg, range < d.l.-2.6 mg/kg and mean 3.4 mg/kg, range < d.l.-16.3 mg/kg wet weight, respectively). Inter-individual variations in contaminant diversity and amounts were noticed. Immediate conservation of the species in the country does not seem to be threatened by global contamination. PMID:22057229

Lemarchand, Charles; Rosoux, René; Pénide, Marie-Eve; Berny, Philippe

2012-01-01

287

Silica sulfuric acid: a versatile and reusable heterogeneous catalyst for the synthesis of N-acyl carbamates and oxazolidinones under solvent-free conditions  

Directory of Open Access Journals (Sweden)

Full Text Available Silica sulfuric acid catalyzes efficiently the reaction of carbamates and oxazolidinones with anhydrides under solvent-free conditions. All the reactions were done at room temperature and the N-acyl carbamates and oxazolidinones were obtained with high yields and purity via an easy work-up procedure. This method is attractive and is in a close agreement with green chemistry.

Liqiang Wu

2011-04-01

288

Simple analytical method for determination of pesticide residues in human serum by liquid chromatography tandem mass spectrometry.  

Science.gov (United States)

The aim of this study was to develop an analytical method for the determination of residues of organophosphorus and carbamate pesticides which are widely used in Tunisia. This method involves a liquid-liquid extraction procedure followed by liquid chromatography tandem mass spectrometry (LC/MS/MS) for the identification and quantification of compounds. Ionization of molecules was performed by the electrospray mode. Multiple reactions monitoring (MRM) was the acquisition mode used for the monitoring of two MS/MS transitions for each compound. The average recoveries obtained, at three different fortification levels, ranged between 65% and 106% for most of the pesticides studied, except for methamidophos (lower than 25%).The linearity of the method was in the range of 5 to 50 micro g/L with a correlation coefficient from 0.995 to 0.999, depending on the analyte. The estimated limit of detection and limit of quantification were 2 micro g/L and 5 micro g/L, respectively. The precision of the analytical procedure was satisfactory and the coefficients of variation, evaluated at three concentration levels were lower than 15% for most pesticides studied. The application of the method was investigated in a population of agricultural workers chronically exposed to various pesticides some of which, such as carbofuran, carbendazim, methomyl and pirimicarb, were detected in some serum samples. PMID:20390957

Araoud, Manel; Douki, Wahiba; Najjar, Mohamed Fadhel; Kenani, Abderraouf

2010-04-01

289

Effect of carbamates on mRNA encoding lipid enzymes in hamster flank organs.  

Science.gov (United States)

Flank organs are an androgen-dependent pilosebaceous complex present in male and female hamsters. These organs have been used for the evaluation of antiandrogenic drugs, which could be used for the treatment of androgen-dependent afflictions. This study demonstrated the role of four different steroidal carbamates 7-10 in the expression of mRNAs coding for different enzymes involved in the lipid metabolism in flank organs. To determine the biological effects of compounds 7-10 on the expression of mRNA coding for lipid enzymes, steroids 7-10, testosterone (T), progesterone (P), and/or 7-10 were applied on the flank organs. Later, the mRNA expression for the enzymes was determined by polymerase chain reaction. The binding of 8 and 9 to the progesterone receptor (PR) as well as their effects on the activity of 5?-reductase were also evaluated. Treatments with T, P, and 7-10 increased the mRNA expression for glycerol 3-phosphate acyl transferase (GPAT), ?-hydroxy-?-methylglutaryl-CoA synthase (HMG-CoA-S), ?-hydroxy-?-methylglutaryl-CoA reductase (HMG-CoA-R), phosphatidylinositol synthase (PI-S), and squalene-synthase (SQ-S). However, the combined treatments with P?+?7-10 decreased the expression of GPAT, HMG-CoA-S, and HMG-CoA-R. Expression of mRNA for all enzymes was variable under treatment with T?+?7-10. Data showed that these carbamates did not bind to the PR, but inhibited the activity of 5?-reductase. Carbamates 7-10 changed the mRNA expression model induced by T and P in flank organs. PMID:24497156

López-Lezama, Juan C; Cabeza, Marisa; Mayorga, Israel; Soriano, Juan; Sainz, Teresita; Bratoeff, Eugene

2014-05-01

290

Cyclic acyl guanidines bearing carbamate moieties allow potent and dirigible cholinesterase inhibition of either acetyl- or butyrylcholinesterase.  

Science.gov (United States)

A series of cyclic acyl guanidine with carbamate moieties have been synthesized and evaluated in vitro for their AChE and BChE inhibitory activities. Structure-activity relationships identified compound 23 as a nanomolar and selective BChE inhibitor, while compound 32 exhibited nanomolar and selective AChE inhibition, selectivity depending on both the structure of the carbamate substituent as well as the position of guanidines-N substitution. The velocity of enzyme carbamoylation was analyzed and showed similar behavior to physostigmine. Phenolic compounds formed after carbamate transfer to the active site of cholinesterases showed additional neuroprotective properties on a hippocampal neuronal cell line (HT-22) after glutamate-induced intracellular reactive oxygen species generation. PMID:25059502

Darras, Fouad H; Kling, Beata; Sawatzky, Edgar; Heilmann, Jörg; Decker, Michael

2014-09-01

291

New Ultra Small Iron-Oxide Nanoparticles with Titanium-Carbamate Coating: Preparation and Magnetic Properties  

Directory of Open Access Journals (Sweden)

Full Text Available 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 (gamma-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 temperature are reported and discussed in view of the superparamagnetic properties and coating effect of these new magnetic nanoparticles.

Domenici V.

2012-08-01

292

Aniline carbamates: a versatile and removable motif for palladium-catalyzed directed c?h activation.  

Science.gov (United States)

The aniline carbamate is introduced as a new removable directing group for C?H activation. Its versatility and ability as a directing group are demonstrated by its use in the ortho-arylation of a wide variety of aniline derivatives under palladium(II) catalysis, with symmetric diaryliodonium salts as aryl donors. The reaction differs from previously reported arylations in its selectivity and its mechanism, as elucidated by kinetic and isotopic experiments. The directing group can also be easily removed under a variety of conditions. PMID:25100441

Uhlig, Nick; Li, Chao-Jun

2014-09-15

293

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.

294

In vitro pesticide degradation in turfgrass soil incubated under open and sealed conditions.  

Science.gov (United States)

Degradation of selected pesticides was conducted in a turfgrass soil from a golf course under open (i.e., allowing gas exchange with atmosphere) and sealed systems. The time required for 50% of the initial dose of fenitrothion (O,O-dimethyl O-4-nitro-m-tolyl phosphorothioate), diazinon (O,O-dimethyl O-2-isopropyl-6-methylpyrimidin4-yl phosphorothioate), iprodione [3-(3,5-dichlorophenyl)-N-isopropyl-2,4-dioxo-imidazolidine-1-carboxamide], mecoprop [(RS)-2-(4-chloro-otolyloxy)propionic acid], and asulam (4-aminophenylsulfonyl-carbamate) to dissipate (half-life, t 1/2) was less than 2 wk under both conditions. The t 1/2 values of dithiopyr (S,S'-dimethyl 2-difluoromethyl-4-isobutyl-6-trifluoro-methylpyridine-3,5-dicarbothioate) were 324 and 185 d under the open and sealed conditions, respectively. The t 1/2 values of isoprothiolane (di-isopropyl 1,3-dithiolan-2-ylidene-malonate), flutolanil (alpha,alpha,alpha-trifluoro-3'-isopropoxy-o-toluanilide), and benefin (N-butyl-N-ethyl-alpha,alpha,alpha-trifluoro-2,6-dinitro-p-toluidine) under the open conditions were 154, 336, and 47 d, respectively. The t 1/2 values of these pesticides increased slightly under the sealed conditions. The t 1/2 values of terbutol (2,6-di-tert-butyl-4-methylphenyl N-methycarbamate) and one of the major degradation products, N-demethyl-terbutol (2,6-di-tert-butyl-4-methylphenyl carbamate), were 182 and 291 d under the open conditions and increased by six- and threefold under the sealed conditions, respectively. The degradation system under the sealed conditions could characterize the persistence of terbutol and N-demethyl-terbutol, which were the most persistent in the field. PMID:11215650

Suzuki, T; Yaguchi, K; Suzuki, S; Suga, T

2001-01-01

295

The IR spectra and hydrogen bonding of toluene-2,6-bis(methyl) and 4,4'-diphenylmethane-bis(methyl) carbamates  

Science.gov (United States)

The IR spectroscopy has been used to study models of polyurethanes containing different hard segments. The spectra of toluene-2,6-bis(methyl) and 4,4'-diphenylmethane-bis(methyl) carbamates at different temperatures were studied. The absorption curves of the free and associated carbamate molecules were compared with experimental IR spectra. The characteristic features of toluene-2,6-bis(methyl) carbamate and methyl- N-methyl carbamate clusters were revealed. The IR spectra for the two most stable toluene-2,6-bis(methyl) carbamate 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.

2000-03-01

296

78 FR 40027 - Novaluron; Pesticide Tolerances  

Science.gov (United States)

...Levels of Concern Once a pesticide's toxicological profile...human exposure to the pesticide. For hazards that have...www.epa.gov/pesticides/factsheets/riskassess...spleen and liver). Dermal short-term (1 to...chemistry (decreased absorption rate =...

2013-07-03

297

78 FR 3333 - Spiromesifen; Pesticide Tolerances  

Science.gov (United States)

...Levels of Concern Once a pesticide's toxicological profile...human exposure to the pesticide. For hazards that have...www.epa.gov/pesticides/factsheets/riskassess...follicles in females. Dermal short-term (1 to...intraspecies rats. absorption rate =...

2013-01-16

298

77 FR 49732 - Cyprodinil; Pesticide Tolerances  

Science.gov (United States)

...human exposure to the pesticide. For hazards that...www.epa.gov/pesticides/factsheets/riskassess...body-weight gain, absorption rate = increased cholesterol...Cancer (Oral, dermal, inhalation) Not likely...performed for a food-use pesticide, if a...

2012-08-17

299

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

300

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

 
 
 
 
301

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

302

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)

303

Pesticide-metabolizing enzymes.  

Science.gov (United States)

Pesticides are known to function as substrates, inhibitors and inducers of drug-metabolizing enzymes, with the same compound frequently acting in more than one of these roles. Current studies of phase I metabolism of pesticides include cytochrome P450 (P450) and the flavin-containing monooxygenase (FMO), with particular reference to individual isozymes. In mouse liver, the level of FMO1 is gender dependent, FMO3 is gender specific, while FMO5 appears to be gender independent. The isozyme specificity of methylenedioxyphenyl synergists for induction of P450 in mouse liver involves P450s 1A1, 1A2 and 2B10, including a non-Ah receptor-dependent mechanism for 1A2 induction. The substrate specificity of mouse and human P450 and FMO isozymes is discussed. PMID:8597134

Hodgson, E; Rose, R L; Ryu, D Y; Falls, G; Blake, B L; Levi, P E

1995-12-01

304

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.

305

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

306

Synthesis and fungicidal activity of aryl carbamic acid-5-aryl-2-furanmethyl ester.  

Science.gov (United States)

Chitin, a major structural component of insect cuticle and fungus cell wall but absent in plants and vertebrates, is regarded as a safe and selective target for pest control agents. Chitin synthesis inhibitors (CSIs) have been well-known as insect growth regulators (IGRs) but rarely found as fungicides in agriculture. To find novel CSIs with good activity, benzoylphenylurea, a typical kind of CSIs, was chosen as the lead compound and 26 novel aryl carbamic acid-5-aryl-2-furanmethyl esters were designed by converting the urea linkages of benzoylphenylureas to carbamic acid esters and changing the aniline parts into furanmethyl groups. The title compounds were synthesized and their structures confirmed by IR, (1)H NMR, and elemental analysis. Preliminary insecticidal and fungicidal bioassays were carried out. The results indicated that the title compounds had no insecticidal effect on Culex pipiens pallens and Plutella xylostella Linnaeus , but most compounds exhibited good fungicidal activities against Corynespora cassiicola , Thanatephorus cucumeris , Botrytis cinerea , and Fusarium oxysporum . In particular, compounds V-4, V-6, V-7, and V-8 showed better activities against the four strains than those of the commercialized fungicides. The morphologic result suggested that compound V-21 had disturbed the cell wall formation of C. cassiicola. The results indicated that modification on the urea linkage of benzoylphenylurea was an effective way to discover new candidates for fungicides. PMID:20151651

Li, Ying; Li, Bao-Ju; Ling, Yun; Miao, Hong-Jian; Shi, Yan-Xia; Yang, Xin-Ling

2010-03-10

307

Enantioselective chromatography and molecular modeling of novel aryloxyaminopropan-2-ols with the alkyl carbamate function.  

Science.gov (United States)

A series of different racemic aryloxyaminopropan-2-ol derivatives 1a-d-3a-d with potential beta-adrenergic blocking effects related to propanolol 4 and atenolol 5 was resolved by HPLC using Chiralcel OD-H and Chiralpak AD as chiral stationary phases. Mobile phases consisted of a hexane/alcohol (propan-2-ol or ethanol) mixture doped with a modifier (DEA or TFA). The retention behavior of the compounds depended on the position of the carbamate attached to the aryloxy moiety and on the length of the alkyl residue in the carbamate. Enantiomers of the title compounds were baseline separated with the separation factors alpha and resolutions R(s) varying in the range of 1.34-4.55 and 1.50-10.65, respectively. The chromatographic systems developed can be used for the determination of the enantiomeric purity of the title compounds. Molecular modelling using empirical molecular mechanics and ab initio quantum chemistry methods provided low-energy structures in which sites of potential interactions responsible for retention behavior and chiral recognition could be identified. PMID:14770409

Navrátilová, Hana; Opatrilová, Radka; Kríz, Zdenek; Koca, Jaroslav

2004-03-01

308

Biochemical evaluation of low dose methyl 2-benzimidazole carbamate fungicide on male albino rats  

Directory of Open Access Journals (Sweden)

Full Text Available

Methyl 2-benzimidazole carbamate (carbendazim is one of the synthetic fungicides that controlled organisms that caused plant diseases of different types. It is widely used as a preservative in leather, paint, textile, fruits and papermaking industry. It is also used as an anticancer drug in chemical medicine. In the present study low concentrations of carbendazim was administered at 5, 10, 25 and 50mM doses intradermally to male albino rats. At the end of 6 hr, 12hr and 24hr duration, blood samples were collected from the animal for the analysis of biochemical and haematological parameters. Carbendazim caused an increase of cholesterol, uric acid, glucose and creatinine while serum phosphorous content was decreased. However, mean hemoglobin, WBC, E, and platelet counts increased and total RBC, N and L counts decreased. These results indicated that low dose level carbendazim contributed to toxicological effects in the rat tissues.

Keywords: Methyl 2-benzimidazole carbamate; Fungicide; Rat tissues

V. Muthuviveganandavel

2011-04-01

309

Analytical approaches for monitoring exposure to organophosphorus and carbamate agents through analysis of protein adducts.  

Science.gov (United States)

Appropriate treatment of a poisoned patient requires knowing the identity of the poison. This review summarizes the methods for identifying poisoning by organophosphorus and carbamate poisons. Mass spectrometry methods identify the poison from the adducts they form with proteins in blood. The most sensitive method uses potassium fluoride to release the organophosphorus agent from its covalent binding to serine 198 of human butyrylcholinesterase. The released poison is identified by gas chromatography-mass spectrometry. The drawback of this method is that it does not detect exposure to agents such as soman, because butyrylcholinesterase adducts with these agents age to a non-reactivatable form. A method that detects both aged and non-aged organophosphylated adducts as well as carbamate adducts is one that digests butyrylcholinesterase with a protease and analyzes the modified peptide by mass spectrometry. This method does not distinguish between poisons that have the same mass after reaction with butyrylcholinesterase--for example, between exposure to chlorpyrifos oxon and paraoxon. Albumin forms a stable, covalent bond with organophosphates on tyrosine 411. The rate of reaction with albumin is much slower than with butyrylcholinesterase, but albumin adducts persist for a longer time in the circulation; they do not age; and they do not release the organophosphate when a patient is treated with an oxime. PMID:22359362

Schopfer, Lawrence M; Lockridge, Oksana

2012-01-01

310

Pesticide-sampling equipment, sample-collection and processing procedures, and water-quality data at Chicod Creek, North Carolina, 1992  

Science.gov (United States)

Water-quality samples were collected from Chicod Creek in the Coastal Plain Province of North Carolina during the summer of 1992 as part of the U.S. Geological Survey's National Water-Quality Assessment Program. Chicod Creek is in the Albemarle-Pamlico drainage area, one of four study units designated to test equipment and procedures for collecting and processing samples for the solid-phase extraction of selected pesticides, The equipment and procedures were used to isolate 47 pesticides, including organonitrogen, carbamate, organochlorine, organophosphate, and other compounds, targeted to be analyzed by gas chromatography/mass spectrometry. Sample-collection and processing equipment equipment cleaning and set-up procedures, methods pertaining to collecting, splitting, and solid-phase extraction of samples, and water-quality data resulting from the field test are presented in this report Most problems encountered during this intensive sampling exercise were operational difficulties relating to equipment used to process samples.

Manning, T. K.; Smith, K. E.; Wood, C. D.; Williams, J. B.

1994-01-01

311

Tracer work in pesticide research  

International Nuclear Information System (INIS)

Innumerable studies on the large number of pesticides being used throughout the world led to some adverse findings on the properties and behavior of these chemicals and their degradation products in revelation to potential toxicity and environmental pollution. However, it is also a fact (difficult to accept as it may) that the use of pesticides as an indirect means of increasing food production cannot yet be dispensed with despite the potential dangers attributed to it. What can be done is to insure its judicious application which means minimizing its effectiveness in controlling pest infestations. To be able to do this it is necessary to know not only what pesticide is to be used against a given pest but also the fate of pesticide after application to a particular environment under prevailing conditions. Knowledge of the distribution and persistence of the parent compounds under metabolites will also help either, to confirm or to dispel the alleged dangers posed by them. Radiotracer methodology is particularly effective for this type of work because it permits highly sensitive analysis with minimum clean-up and permits one to determine even the bound residues which defies ordinary extraction procedures. Some studies made are studies on fate of pesticides in plant after foliar application to plant needs, uptake and translocation of systemic pesticides, fate of pesticides in soil, bioaccumulation of pesticide by aquatic organisms, etc. This particular study is on distribution of pesticide among the components of a rice/fish ecosystem. This project aims to generate data from experiments conducted in a model ecosystem using radiolabelled lindane and carbo-furan. In both cases, results show a decline in extractable species from the recommended dosage of pesticide application although they tend to imbibe a considerable amount of pesticide. It is hoped that depuration in additional experiments will bring useful results. (Auth.)

312

PESTICIDE TESTING WITH LITTORAL ENCLOSURES  

Science.gov (United States)

The littoral enclosures research design and protocol were designed to use in developing a field test guidance document to use in the pesticide registration process. ith its use, the primary and secondary (ecological) effects of pesticides on the structure and function of lentic e...

313

NANOTECHNOLOGY AND NANOENCAPSULATION OF PESTICIDES  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This paper is about nano-technology perspectives and their applications in the pesticides development. Information on companies that are participating in microencapsulate pesticide production is present, as well as nanotechnology concepts, and companies that make micro and nano-encapsulate pest formulations.

Eder Lugo-Medina; Cipriano García-Gutiérrez; Rey David Ruelas-Ayala

2010-01-01

314

Choice of pesticide fate models  

International Nuclear Information System (INIS)

The choice of a pesticide fate model at field scale is linked to the available input data. The article describes the available pesticide fate models at a field scale and the guidelines for the choice of the suitable model as function of the data input requested

315

Synthesis of CdS and CdSe nanoparticles by thermolysis of diethyldithio- or diethyldiseleno-carbamates of cadmium  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Cadmium sulfide and cadmium selenide nanoparticles have been synthesised by a novel route involving the thermal decomposition of the bisdiethyldithio- or bisdiethyldiseleno-carbamates of cadmium in refluxing 4-ethylpyridine solutions. The nanodispersed materials were studied by electronic spectroscopy and bandgaps were blue shifted. Transmission electron microscopy of the samples showed material to be in the nanosize range and crystalline.

Trindade, Tito; O Brien, Paul

1996-01-01

316

Gold-catalyzed intramolecular hydroamination of o-alkynylbenzyl carbamates: a route to chiral fluorinated isoindoline and isoquinoline derivatives.  

Science.gov (United States)

Enantiomerically pure fluorinated isoindoline and dihydroisoquinoline scaffolds have been prepared through a diastereoselective addition of fluorinated nucleophiles to Ellman's N-(tert-butanesulfinyl)imines followed by a sequence of Sonogashira cross-coupling/gold(I)-catalyzed cycloisomerization of the corresponding carbamate. A more favored 5-exo-dig mechanism was observed mainly due to an electronic effect of the fluorinated group. PMID:23360473

Fustero, Santos; Ibáñez, Ignacio; Barrio, Pablo; Maestro, Miguel A; Catalán, Silvia

2013-02-15

317

One-step Extraction of Multiresidue Pesticides in Soil by Microwave-assisted Extraction Technique  

Directory of Open Access Journals (Sweden)

Full Text Available A screening multi-residues method based on the Microwave-Assisted Extraction (MAE technique has been optimized using soil samples collected from 15 regions in Saudi Arabia. This method was used to extract 12 pesticide residues with a broad range of physico-chemical properties in agricultural soils containing to Organophosphorous, Organochlorines, Pyrethroids and Carbamates mainly used in agriculture. All MAE factors affecting the extraction techniques (heating, pressure, power, time and solvent volume of the targeted compounds were studied through experimental design to obtain a simple MAE method and evaluate the optimum extraction condition compared with traditional Soxhlet method for soil samples. The tested pesticide residues in the extracts of both techniques were analyzed by Gas Chromatography-Mass Spectrometer (GC-MS. The results were compared for the percentage of recovery, time consumption and volume of organic solvent used in each extraction procedure. The results indicated that the MAE method had the advantages resulting from the use of a low volume of organic solvent (acetone: hexane, 3:2, an unnecessary cleanup step and good efficiency to extract different groups of pesticides in soils at residual levels in 20 min, this compared with Soxhlet method. All the compounds extracted by MAE method were recovered in good yields and Minimum Detection Limits (MDL ranging from 0.0001 to 0.004 mg kg-1. The MAE approach was efficient and faster than the Soxhlet method in determining 12 multi-residue pesticides with a broad range of physico-chemical properties in soils without cleanup of the extracts.

A.G. Al- Ghamdi

2010-01-01

318

The ARS Pesticide Properties Database  

Science.gov (United States)

Maintained by the Agricultural Research Service's (ARS) Remote Sensing and Modeling Lab, the ARS Pesticide Properties Database "is a compendium of chemical and physical properties of 324 widely used pesticides." The database, organized alphabetically, focuses on "16 of the most important properties" affecting pesticide transport and degradation characteristics under different soil and weather conditions. For each pesticide, users will find information on CASRN, Molecular formula, Molecular weight, Physical state, Boiling point, Melting point, Decomposition point, Heat of vaporization, Rate Constants-Hydrolysis (Photolysis), Vapor pressure, Water solubility, Organic solubility, Henry's Law, Octanol/ water partitioning, Acid dissociation, Soil sorption, Field dissipation, and Soil halflife (aerobic, anaerobic). Also provided are several sections describing the properties and units of pesticide parameters, a Coden list, and links to a few related sites.

2005-12-06

319

Cumulative risk assessment of pesticide residues in food.  

Science.gov (United States)

There is increasing need to address the potential risks of combined exposures to multiple residues from pesticides in the diet. The available evidence suggests that the main concern is from dose addition of those compounds that act by the same mode of action. The possibility of synergy needs to be addressed on a case-by-case basis, where there is a biologically plausible hypothesis that it may occur at the levels of residues occurring in the diet. Cumulative risk assessment is a resource-intense activity and hence a tiered approach to both toxicological evaluation and intake estimation is recommended, and the European Food Safety Authority (EFSA) has recently published such a proposal. Where assessments have already been undertaken by some other authority, full advantage should be taken of these, subject of course to considerations of quality and relevance. Inclusion of compounds in a cumulative assessment group (CAG) should be based on defined criteria, which allow for refinement in a tiered approach. These criteria should include chemical structure, mechanism of pesticidal action, target organ and toxic mode of action. A number of methods are available for cumulating toxicity. These are all inter-related, but some are mathematically more complex than others. The most useful methods, in increasing levels of complexity and refinement, are the hazard index, the reference point index, the Relative Potency Factor method and physiologically based toxicokinetic modelling, although this last method would only be considered should a highly refined assessment be necessary. Four possible exposure scenarios are of relevance for cumulative risk assessment, acute and chronic exposure in the context of maximum residue level (MRL)-setting, and in relation to exposures from the actual use patterns, respectively. Each can be addressed either deterministically or probabilistically. Strategies for dealing with residues below the limit of detection, limit of quantification or limit of reporting need to be agreed. A number of probabilistic models are available, but some of there are geographically constrained due to the underlying datasets used in their construction. Guidance on probabilistic modelling needs to be finalised. Cumulative risk assessments have been performed in a number of countries, on organophosphate insecticides alone (USA) or together with carbamates (UK, DK, NL), triazines, chloroacetanilides, carbamates alone (USA), and all pesticides (DE). All identifiable assumptions and uncertainties should be tabulated and evaluated, at least qualitatively. Those likely to have a major impact on the outcome of the assessment should be examined quantitatively. In cumulative risk assessment, it is necessary, as in other risk assessments, for risk managers to consider what level of risk would be considered "acceptable", for example what percentile of the population should be below the reference value. Criteria for prioritising CAGs for cumulative risk assessment include frequency of detection in monitoring programmes, high usage, high exposure relative to the reference value, large number of compounds (e.g. five or more) in a group. PMID:18585444

Boobis, Alan R; Ossendorp, Bernadette C; Banasiak, Ursula; Hamey, Paul Y; Sebestyen, Istvan; Moretto, Angelo

2008-08-15

320

Progress in studies on genotoxicity of pesticides  

International Nuclear Information System (INIS)

Pesticides are playing an important role in food production and food security. However, the ecoenvironment and human being could be impacted by improper use of some pesticides. An increasing attention has been paid to genotoxicity of pesticide and a progress has been made in recent years. The methodology, results, and probable mechanisms of genotoxicity of pesticide are reviewed in this article. (authors)

 
 
 
 
321

Organochlorine pesticides and endometriosis.  

Science.gov (United States)

Limited study of persistent organochlorine pesticides (OCPs) and endometriosis has been conducted. One hundred women aged 18-40 years who were undergoing laparoscopy provided 20 cm(3) of blood for toxicologic analysis and surgeons completed operative reports regarding the presence of endometriosis. Gas chromatography with electron capture was used to quantify (ng/g serum) six OCPs. Logistic regression was utilized to estimate the adjusted odds ratios (aOR) and 95% confidence intervals (CI) for individual pesticides and groups based on chemical structure adjusting for current cigarette smoking and lipids. The highest tertile of aromatic fungicide was associated with a fivefold risk of endometriosis (aOR=5.3; 95% CI, 1.2-23.6) compared to the lowest tertile. Similar results were found for t-nonachlor and HCB. These are the first such findings in a laproscopic cohort that suggest an association between OCP exposure and endometriosis. More prospective studies are necessary to ensure temporal ordering and confirm these findings. PMID:20580667

Cooney, Maureen A; Buck Louis, Germaine M; Hediger, Mary L; Vexler, Albert; Kostyniak, Paul J

2010-11-01

322

The Greening of Pesticide–Environment Interactions: Some Personal Observations  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Background: Pesticide–environment interactions are bidirectional. The environment alters pesticides by metabolism and photodegradation, and pesticides in turn change the environment through nontarget or secondary effects.

Casida, John E.

2012-01-01

323

40 CFR 152.175 - Pesticides classified for restricted use.  

Science.gov (United States)

...PROCEDURES Classification of Pesticides § 152.175 Pesticides classified for restricted... The following uses of pesticide products containing...mixtures with fungicides and chlorinated hydrocarbon, inorganic phosphate...

2010-07-01

324

Organofosforados e carbamatos no leite produzido em quatro regiões leiteiras no Brasil: ocorrência e ação sobre Listeria monocytogenes e Salmonella spp. / Organophosphates and carbamates in milk produced in four milk producing regions from Brazil: occurrence and activity against Listeria monocytogenes and Salmonella spp.  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Organofosforados e carbamatos são compostos utilizados no controle de parasitas em animais e podem gerar resíduos nos produtos alimentícios derivados, representando um risco para o consumidor. O presente estudo objetivou pesquisar a presença de resíduos de organofosforados e carbamatos em leite cru [...] produzido em quatro regiões leiteiras no Brasil e verificar se a presença desses compostos teria alguma relação com a ausência de Listeria monocytogenes e Salmonella spp., anteriormente observada nessas amostras. Entre 209 amostras analisadas, a presença de ao menos um desses compostos foi detectada em 196 (93,8%). Para a avaliação da sua interferência na detecção de L. monocytogenes e Salmonella spp., 28 amostras de leite positivas e negativas para esses compostos foram submetidas à fervura por 10 minutos e adicionadas desses patógenos, monitorando-se sua multiplicação durante armazenamento a 4 °C e a 25 °C. Não houve diferença significativa (p Abstract in english Chemical residues may be present in foods due to contamination in early stages of production, posing a potential risk to consumers. Organophosphates and carbamates are used in the control of parasites in animals and may generate residues in foods derived from these animals, like milk. This study aim [...] ed to survey the presence of these two pesticides in raw milk samples collected in four important milk-producing regions in Brazil and observe any possible relationship between presence of these compounds and the previously reported absence of Listeria monocytogenes e Salmonella spp. in the same milk samples. Organophosphates and/or carbamates were detected in 196 (93.8%) out of 209 samples. For evaluation of the interference of these products on detection of L. monocytogenes and Salmonella spp., 28 milk samples containing these pesticides were boiled for 10 minutes, added of the pathogens, and their multiplication was monitored during storage at 4 °C and 25 °C. No significant differences (p

Luís Augusto, Nero; Marcos Rodrigues de, Mattos; Vanerli, Beloti; Márcia Aguiar Ferreira, Barros; Daisy Pontes, Netto; Bernadette Dora Gombossy de Melo, Franco.

325

Synthesis of kenaf cellulose carbamate using microwave irradiation for preparation of cellulose membrane.  

Science.gov (United States)

Cellulose carbamate (CCs) was produced from kenaf core pulp (KCP) using microwave reactor-assisted method. The effects of urea concentration and reaction time on the formation of nitrogen content in CCs were investigated. The CCs' solubility in LiOH/urea system was determined and its membranes were characterized. As the urea content and reaction time increased, the nitrogen content form in CCs increased which enhanced the CCs' solubility. The formation of CCs was confirmed by Fourier transform infrared spectroscopy (FT-IR) and nitrogen content analysis. The CCs' morphology was examined using Scanning electron microscopy (SEM). The cellulose II and crystallinity index of the membranes were confirmed by X-ray diffraction (XRD). The pore size of the membrane displayed upward trend with respect to the urea content observed under Field emission scanning electron microscope (FESEM). This investigation provides a simple and efficient procedure of CCs determination which is useful in producing environmental friendly regenerated CCs. PMID:24721064

Gan, Sinyee; Zakaria, Sarani; Chia, Chin Hua; Kaco, Hatika; Padzil, Farah Nadia Mohammad

2014-06-15

326

Formation of ethyl carbamate and changes during fermentation and storage of yellow rice wine.  

Science.gov (United States)

Ethyl carbamate (EC) was analyzed during yellow rice wine production and storage. EC increased slowly during fermentation and rapidly after frying and sterilization. Less amount of EC was formed when cooled rapidly to 30 °C than when cooled naturally. High temperature and long storage time increased EC formation. After 400 days storage, EC increased from 74.0 to 84.2, 131.8 and 509.4 ?g/kg at 4 °C, room temperature and 37 °C, respectively, and there was significantly difference between the fried wine and the wine on sale from 2011 (pwine fermentation and was above 20 mg/kg after the wine was fried; urea contributed to EC formation when the fried wine was cooled slowly. These results indicate that it is necessary for industry to optimize the wine frying conditions, such as temperature, time and cooling process in order to decrease EC formation. PMID:24444913

Wu, Pinggu; Cai, Chenggang; Shen, Xianghong; Wang, Liyuan; Zhang, Jing; Tan, Ying; Jiang, Wei; Pan, Xiaodong

2014-01-01

327

A general method for tritium labelling of benzimidazole carbamates by catalytic exchange in dioxane solutions  

International Nuclear Information System (INIS)

Benzimidazole carbamates (BZCs) act as inhibitors of the tubulin-microtubule equilibria in eukaryotic organisms. Recently drug resistance to this class of compounds in helminth parasites has been shown to be due to a reduced ability of resistant tubulin to bind BZCs. In order to quantitate the nature of the tubulin-BZC interaction a general method for the specific tritium labelling of BZCs has been developed. The BZCs: mebendazole, oxfendazole, parbendazole, oxibendazole, albendazole and fenbendazole were labelled by catalytic exchange using palladium on calcium carbonate in pure dioxane at 600C under tritium gas. The position of label incorporation for tritiated albendazole was determined by tritium-NMR as the 4-position of benzimadazole nucleus. The yields for individual BZCs varied from 8 to 68% for a range of specific activity of 0.44 to 13.4 Ci/mmole. (author)

328

A general method for tritium labelling of benzimidazole carbamates by catalytic exchange in dioxane solutions  

Energy Technology Data Exchange (ETDEWEB)

Benzimidazole carbamates (BZCs) act as inhibitors of the tubulin-microtubule equilibria in eukaryotic organisms. Recently drug resistance to this class of compounds in helminth parasites has been shown to be due to a reduced ability of resistant tubulin to bind BZCs. In order to quantitate the nature of the tubulin-BZC interaction a general method for the specific tritium labelling of BZCs has been developed. The BZCs: mebendazole, oxfendazole, parbendazole, oxibendazole, albendazole and fenbendazole were labelled by catalytic exchange using palladium on calcium carbonate in pure dioxane at 60{sup 0}C under tritium gas. The position of label incorporation for tritiated albendazole was determined by tritium-NMR as the 4-position of benzimadazole nucleus. The yields for individual BZCs varied from 8 to 68% for a range of specific activity of 0.44 to 13.4 Ci/mmole. (author).

Lacey, E. (Commonwealth Scientific and Industrial Research Organization, Glebe, NSW (Australia). Div. of Animal Health, McMaster Lab.); Dawson, M. (Sydney Univ. (Australia). Dept. of Pharmacy); Long, M.A.; Than, C. (New South Wales Univ., Kensington (Australia). School of Chemistry)

1989-12-01

329

Solubility improvement of an anthelmintic benzimidazole carbamate by association with dendrimers  

International Nuclear Information System (INIS)

The improvement of aqueous solubility of methyl (5-[propylthio]-1H-benzimidazole-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, fluorescence emission measurements and by 1H-NMR spectroscopy. The results obtained show that these polymeric structures have the capacity to enhance the solubility of ABZ, both lipophilic and specific hydrogen bond interactions contributing to the guest-host association. Although all studied dendrimers have hydrophobic internal nanoenvironments with similar dimensions, their surfaces differ significantly and the nature and the localization of the interactions involved in ABZ-dendrimer association depend on the type of terminal groups. (author)

330

Solubility improvement of an anthelmintic benzimidazole carbamate by association with dendrimers  

Energy Technology Data Exchange (ETDEWEB)

The improvement of aqueous solubility of methyl (5-[propylthio]-1H-benzimidazole-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, fluorescence emission measurements and by {sup 1}H-NMR spectroscopy. The results obtained show that these polymeric structures have the capacity to enhance the solubility of ABZ, both lipophilic and specific hydrogen bond interactions contributing to the guest-host association. Although all studied dendrimers have hydrophobic internal nanoenvironments with similar dimensions, their surfaces differ significantly and the nature and the localization of the interactions involved in ABZ-dendrimer association depend on the type of terminal groups. (author)

Fernandez, L.; Sigal, E.; Santo, M., E-mail: msanto@exa.unrc.edu.ar [Departamento de Fisica, Facultad de Ciencias Exactas Fisicoquimicas y Naturales, Universidad Nacional de Rio Cuarto (Argentina); Otero, L.; Silber, J. J. [Departamento de Quimica. Facultad de Ciencias Exactas Fisicoquimicas y Naturales, Universidad Nacional de Rio Cuarto, Rio Cuarto (Argentina)

2011-10-15

331

Rapid labeling of metabolically engineered cell-surface glycoconjugates with a carbamate-linked cyclopropene reporter.  

Science.gov (United States)

Metabolic oligosaccharide engineering is a valuable tool to monitor cellular carbohydrates. Here, we report the synthesis of a novel N-acyl-mannosamine derivative bearing a methylcyclopropene tag that is attached to the sugar via a carbamate moiety. This derivative undergoes rapid Diels-Alder reaction with inverse electron demand. We demonstrate that the cell's biosynthetic machinery incorporates this non-natural mannosamine derivative into glycoconjugates that can, subsequently, be labeled within less than 10 min with a new sulfo-Cy3-tetrazine conjugate. Using this tetrazine-dye conjugate for the detection of the methylcyclopropene-tagged mannosamine derivative, we could achieve dual labeling of two different metabolically incorporated sugars combining a Diels-Alder reaction with inverse electron demand and a strain-promoted azide-alkyne cycloaddition which are carried out simultaneously in a single step. PMID:24328258

Späte, Anne-Katrin; Bußkamp, Holger; Niederwieser, Andrea; Schart, Verena F; Marx, Andreas; Wittmann, Valentin

2014-01-15

332

Detection of arc genes related with the ethyl carbamate precursors in wine lactic acid bacteria.  

Science.gov (United States)

Trace amounts of the carcinogen ethyl carbamate can appear in wine by the reaction of ethanol with compounds such as citrulline and carbamyl phosphate, which are produced from arginine degradation by some wine lactic acid bacteria (LAB). In this work, the presence of arc genes for the arginine-deiminase pathway was studied in several strains of different species of LAB. Their ability to degrade arginine was also studied. To detect the presence of arc genes, degenerate primers were designed from the alignment of protein sequences in already sequenced LAB. The usefulness of these degenerate primers has been proven by sequencing some of the amplified PCR fragments and searching for homologies with published sequences of the same species and related ones. Correlation was found between the presence of genes and the ability to degrade arginine. Degrading strains included all heterofermentative lactobacilli, Oenococcus oeni , Pediococcus pentosaceus , and some strains of Leuconostoc mesenteroides and Lactobacillus plantarum . PMID:19219988

Araque, Isabel; Gil, Joana; Carreté, Ramon; Bordons, Albert; Reguant, Cristina

2009-03-11

333

Uptake and translocation of methyl(1-butylcarbamyl)-2 benzimidazole carbamate in wheat  

International Nuclear Information System (INIS)

Evidence of penetration of 14C labelled benomyl (Methyl-1 (butylcarbmyl)-2 benzimidazole carbamate) into embryo and endosperm within one hr of its dressing on wheat seed was obtained. The mean percentage distribution of the total 14C recovered in embryo and endosperm fractions of the seed was 0.34 and 31.11, respectively. During germination, activity increased gradually with the age of seedlings. The fungicide was identified chemically and quantitatively determined in plants of different ages raised from treated seed. There was build up of concentration of fungicide in the shoots upto 15 days after which it decreased. No fungicide was detectable in grains. Physical factors of the environment influenced the rate of uptake of fungicide, maximum translocation occurring under conditions of high temperature (30deg C) or low relative humidity (30%). (auth.)

334

Ortho effects in quantitative structure-activity relationships for acetylcholinesterase inhibition by aryl carbamates.  

Science.gov (United States)

Ortho-substituted phenyl-N-butyl carbamates (1-9) are characterized as "pseudo-pseudo-substrate" inhibitors of acetylcholinesterase. Since the inhibitors protonate at pH 7.0 buffer solution, the virtual inhibition constants (K'is) of the protonated inhibitors are calculated from the equation, - logK'i = - logKi - logKb. The logarithms of the inhibition constant (Ki), the carbamylation constant (k(c)), and the bimolecular inhibition constant (k(i)) for the enzyme inhibitions by carbamates 1-9 are multiply linearly correlated with the Hammett para-substituent constant (sigma(p)), the Taft-Kutter-Hansch ortho steric constant (E(S)), and the Swan-Lupton ortho polar constant (F). Values of rho, delta, and f for the - logKi-, logk(c)-, and logk(i)-correlations are -0.6, -0.16, 0.7; 0.11, 0.03, -0.3; and - 0.5, - 0.12, 0.4, respectively. The Ki step further divides into two steps: 1) the pre-equilibrium protonation of the inhibitors, Kb step and 2) formation of a negatively charged enzyme-inhibitor Michaelis-Menten complex--virtual inhibition, K'i step. The Ki step has little ortho steric enhancement effect; moreover, the k(c)step is insensitive to the ortho steric effect. The f value of 0.7 for the Ki step indicates that ortho electron-withdrawing substituents of the inhibitors accelerate the inhibition reactions from the ortho polar effect; however, the f value of -0.3 for the k(c)step implies that ortho electron-withdrawing substituents of the inhibitors lessen the inhibition reactions from the ortho polar effect. PMID:15648653

Lin, Gialih; Liu, Yu-Chen; Lin, Yan-Fu; Wu, Yon-Gi

2004-10-01

335

Structural basis for inactivation of Giardia lamblia carbamate kinase by disulfiram.  

Science.gov (United States)

Carbamate kinase from Giardia lamblia is an essential enzyme for the survival of the organism. The enzyme catalyzes the final step in the arginine dihydrolase pathway converting ADP and carbamoyl phosphate to ATP and carbamate. We previously reported that disulfiram, a drug used to treat chronic alcoholism, inhibits G. lamblia CK and kills G. lamblia trophozoites in vitro at submicromolar IC50 values. Here, we examine the structural basis for G. lamblia CK inhibition of disulfiram and its analog, thiram, their activities against both metronidazole-susceptible and metronidazole-resistant G. lamblia isolates, and their efficacy in a mouse model of giardiasis. The crystal structure of G. lamblia CK soaked with disulfiram revealed that the compound thiocarbamoylated Cys-242, a residue located at the edge of the active site. The modified Cys-242 prevents a conformational transition of a loop adjacent to the ADP/ATP binding site, which is required for the stacking of Tyr-245 side chain against the adenine moiety, an interaction seen in the structure of G. lamblia CK in complex with AMP-PNP. Mass spectrometry coupled with trypsin digestion confirmed the selective covalent thiocarbamoylation of Cys-242 in solution. The Giardia viability studies in the metronidazole-resistant strain and the G. lamblia CK irreversible inactivation mechanism show that the thiuram compounds can circumvent the resistance mechanism that renders metronidazole ineffectiveness in drug resistance cases of giardiasis. Together, the studies suggest that G. lamblia CK is an attractive drug target for development of novel antigiardial therapies and that disulfiram, an FDA-approved drug, is a promising candidate for drug repurposing. PMID:24558036

Galkin, Andrey; Kulakova, Liudmila; Lim, Kap; Chen, Catherine Z; Zheng, Wei; Turko, Illarion V; Herzberg, Osnat

2014-04-11

336

Pesticide use and application: An Indian scenario  

Energy Technology Data Exchange (ETDEWEB)

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.

Abhilash, P.C., E-mail: pcabhilash@gmail.com [Eco-Auditing Group, National Botanical Research Institute, Council of Scientific and Industrial Research, Rana Pratap Marg, Lucknow 226001, Uttar Pradesh (India); Singh, Nandita, E-mail: nanditasingh8@yahoo.co.in [Eco-Auditing Group, National Botanical Research Institute, Council of Scientific and Industrial Research, Rana Pratap Marg, Lucknow 226001, Uttar Pradesh (India)

2009-06-15

337

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

338

Discriminação quiral por CLAE em carbamatos de polissacarídeos: desenvolvimento, aplicações e perspectivas Polysaccharide carbamate as chiral stationary phases for HPLC: development, applications and perspectives  

Directory of Open Access Journals (Sweden)

Full Text Available The importance of chromatographic separation of enantiomers has been acknowledged. This review surveys the development, application and perspectives of polysaccharide carbamates as chiral stationary phase for HPLC.

Quezia B. Cass

1997-02-01

339

Carbamato de etila em bebidas alcoólicas (cachaça, tiquira, uísque e grapa Ethyl carbamate in alcoholic beverages (cachaça, tiquira, whisky and grape  

Directory of Open Access Journals (Sweden)

Full Text Available The presence of ethyl carbamate in cachaças, tiquiras, whiskies and grapes was investigated by GC-MS, monitoring the m/z 62 ion. The external standard method was used for quantitation in 188 samples (126 cachaças, 37 tiquiras, 6 grappas and 19 whiskies. The results of the study for cachaça were analysed considering the geographic origin, distillation type (still or column, bottle coloration (amber or transparent and ageing. The average contents of ethyl carbamate in cachaças and tiquiras were 0.77 and 2.4 mg L-1, respectively. These values were higher than the mean concentration found in grapes (0.045 mg L-1 and whiskies (0.14 mg L-1. On average the cachaças distilled in column tend to present higher values of ethyl carbamate than those from still. In the sampling studied it was not possible to define a correlation between content of ethyl carbamate, bottle coloration and ageing time.

Luiz Gualberto de Andrade-Sobrinho

2002-12-01

340

Enhancement of the efficacy of a carbamate nematicide against the potato cyst nematode, Globodera pallida, through mycorrhization in commercial potato fields.  

Science.gov (United States)

Two experiments were conducted over 2 years in commercial potato fields in Shropshire, UK, to evaluate the compatibility of the nematicide aldicarb with commercial inocula of arbuscular mycorrhizal fungi (AMF) in the control of the potato cyst nematode Globodera pallida. The AMF used were Vaminoc (mixed-AMF inoculum), Glomus intraradices (BioRize BB-E) and G. mosseae (isolate BEG 12). In the absence of AMF, the in-soil hatch of G. pallida increased 30% (P potato (cv. Golden Wonder) tubers with AMF eliminated this delay in G. pallida hatch by stimulating a mean increase of 32% (P < 0.01) in hatch within 2 wk after planting. In the aldicarb-treated plots in Experiment 1, G. pallida multiplication rate was 38% lower (P < 0.05) in roots of AMF-inoculated than noninoculated plants, but in Experiment 2, this effect was slightly lower (P = 0.07). In these plots, the single AMF inocula showed also a weak trend (P = 0.10) towards greater tuber yields relative to their noninoculated counterparts. Mycorrhization therefore appears to enhance the efficacy of carbamate nematicides against G. pallida and consequently more research is proposed to validate these findings and fully explore the potential of this model. PMID:22736833

Deliopoulos, T; Minnis, S T; Jones, P W; Haydock, P P J

2010-03-01

 
 
 
 
341

Prediction of Multi-Target Networks of Neuroprotective Compounds with Entropy Indices and Synthesis, Assay, and Theoretical Study of New Asymmetric 1,2-Rasagiline Carbamates  

Science.gov (United States)

In a multi-target complex network, the links (Lij) represent the interactions between the drug (di) and the target (tj), characterized by different experimental measures (Ki, Km, IC50, etc.) obtained in pharmacological assays under diverse boundary conditions (cj). In this work, we handle Shannon entropy measures for developing a model encompassing a multi-target network of neuroprotective/neurotoxic compounds reported in the CHEMBL database. The model predicts correctly >8300 experimental outcomes with Accuracy, Specificity, and Sensitivity above 80%–90% on training and external validation series. Indeed, the model can calculate different outcomes for >30 experimental measures in >400 different experimental protocolsin relation with >150 molecular and cellular targets on 11 different organisms (including human). Hereafter, we reported by the first time the synthesis, characterization, and experimental assays of a new series of chiral 1,2-rasagiline carbamate derivatives not reported in previous works. The experimental tests included: (1) assay in absence of neurotoxic agents; (2) in the presence of glutamate; and (3) in the presence of H2O2. Lastly, we used the new Assessing Links with Moving Averages (ALMA)-entropy model to predict possible outcomes for the new compounds in a high number of pharmacological tests not carried out experimentally. PMID:25255029

Romero Duran, Francisco J.; Alonso, Nerea; Caamano, Olga; Garcia-Mera, Xerardo; Yanez, Matilde; Prado-Prado, Francisco J.; Gonzalez-Diaz, Humberto

2014-01-01

342

A fish of many scales: extrapolating sublethal pesticide exposures to the productivity of wild salmon populations.  

Science.gov (United States)

For more than a decade, numerous pesticides have been detected in river systems of the western United States that support anadromous species of Pacific salmon and steelhead. Over the same interval, several declining wild salmon populations have been listed as either threatened or endangered under the U.S. Endangered Species Act (ESA). Because pesticides occur in surface waters that provide critical habitat for ESA-listed stocks, they are an ongoing concern for salmon conservation and recovery throughout California and the Pacific Northwest. Because pesticide exposures are typically sublethal, a key question is whether toxicological effects at (or below) the scale of the individual animal ultimately reduce the productivity and recovery potential of wild populations. In this study we evaluate how the sublethal impacts of pesticides on physiology and behavior can reduce the somatic growth of juvenile chinook salmon (Oncorhynchus tshawytscha) and, by extension, subsequent size-dependent survival when animals migrate to the ocean and overwinter in their first year. Our analyses focused on the organophosphate and carbamate classes of insecticides. These neurotoxic chemicals have been widely detected in aquatic environments. They inhibit acetylcholinesterase, an enzyme in the salmon nervous system that regulates neurotransmitter-mediated signaling at synapses. Based on empirical data, we developed a model that explicitly links sublethal reductions in acetylcholinesterase activity to reductions in feeding behavior, food ration, growth, and size at migration. Individual size was then used to estimate size-dependent survival during migration and transition to the sea. Individual survival estimates were then integrated into a life-history population projection matrix and used to calculate population productivity and growth rate. Our results indicate that short-term (i.e., four-day) exposures that are representative of seasonal pesticide use may be sufficient to reduce the growth and size at ocean entry of juvenile chinook. The consequent reduction in individual survival over successive years reduces the intrinsic productivity (lambda) of a modeled ocean-type chinook population. Overall, we show that exposures to common pesticides may place important constraints on the recovery of ESA-listed salmon species, and that simple models can be used to extrapolate toxicological impacts across several scales of biological complexity. PMID:20014574

Baldwin, David H; Spromberg, Julann A; Collier, Tracy K; Scholz, Nathaniel L

2009-12-01

343

Movement of pesticides from the site of application  

International Nuclear Information System (INIS)

echanisms 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

344

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

345

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

346

Dynamic kinetic resolution of 1,3-dihydro-2H-isoindole-1-carboxylic acid methyl ester: asymmetric transformations toward isoindoline carbamates.  

Science.gov (United States)

Asymmetric syntheses of isoindoline carbamates have been successfully achieved through enzyme-mediated dynamic kinetic resolution processes and without requirement of metal or acid-base catalyst for the substrate racemization. Optically active carbamates were obtained in good yields and an excellent degree of stereoselectivity when Pseudomonas cepacia lipase (PSL) was used as biocatalyst, with diallyl or dibenzyl carbonates being both adequate reagents in alkoxycarbonylation reactions. PMID:22417293

Morán-Ramallal, Roberto; Gotor-Fernández, Vicente; Laborda, Pedro; Sayago, Francisco J; Cativiela, Carlos; Gotor, Vicente

2012-04-01

347

Pesticide movement and water management  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

348

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

349

40 CFR 180.3 - Tolerances for related pesticide chemicals.  

Science.gov (United States)

...false Tolerances for related pesticide chemicals. 180.3 Section 180.3 Protection...TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Definitions and Interpretative...3 Tolerances for related pesticide chemicals. (a) Pesticide chemicals...

2010-07-01

350

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

351

Efficient hydrogenation of organic carbonates, carbamates and formates indicates alternative routes to methanol based on CO2 and CO  

Science.gov (United States)

Catalytic hydrogenation of organic carbonates, carbamates and formates is of significant interest both conceptually and practically, because these compounds can be produced from CO2 and CO, and their mild hydrogenation can provide alternative, mild approaches to the indirect hydrogenation of CO2 and CO to methanol, an important fuel and synthetic building block. Here, we report for the first time catalytic hydrogenation of organic carbonates to alcohols, and carbamates to alcohols and amines. Unprecedented homogeneously catalysed hydrogenation of organic formates to methanol has also been accomplished. The reactions are efficiently catalysed by dearomatized PNN Ru(II) pincer complexes derived from pyridine- and bipyridine-based tridentate ligands. These atom-economical reactions proceed under neutral, homogeneous conditions, at mild temperatures and under mild hydrogen pressures, and can operate in the absence of solvent with no generation of waste, representing the ultimate ‘green’ reactions. A possible mechanism involves metal-ligand cooperation by aromatization-dearomatization of the heteroaromatic pincer core.

Balaraman, Ekambaram; Gunanathan, Chidambaram; Zhang, Jing; Shimon, Linda J. W.; Milstein, David

2011-08-01

352

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

353

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

International Nuclear Information System (INIS)

To detect effects of pesticides on non-target freshwater organisms the Species at risk (SPEARpesticides) 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 SPEARpesticides 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)pesticides is not significantly lower than the species-level index. The results suggest that the family-level SPEAR(fm)pesticides is a sensitive, cost-effective, and potentially European-wide bioindicator of pesticide contamination in flowing waters. Class boundaries for SPEARpesticides according to EU Water Framework Directive are defined to contribute to the assessment of ecological status of water bodies. - We show that SPEARpesticides can be based on family-level biomonitoring data and is applicable for large-scale monitoring programmes to detect and quantify pesticide contamination.

354

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

355

Part I: temporal and spatial distribution of multiclass pesticide residues in lake waters of Northern Greece: application of an optimized SPE-UPLC-MS/MS pretreatment and analytical method.  

Science.gov (United States)

The present work describes the application of an analytical procedure, utilizing ultra performance liquid chromatography (UPLC) coupled with mass spectrometry instrumentation, for the determination of 253 multiclass pesticides, classified in six different groups. Solid phase extraction was applied for the isolation and pre-concentration of target compounds in water samples. Surface waters of the lakes located in Northern Greece (Volvi, Doirani, and Kerkini), were collected in two time periods (fall/winter 2010 and spring/summer 2011) and analyzed, applying the developed analytical methods. Spatial distribution of detected pesticides was visualized using interpolation methods and geographical information systems (GIS). Pesticides with maximum concentrations were amitrole, propoxur, simazine, chlorpyrifos, carbendazim, triazophos, disulfoton-sulfone, pyridaben, sebuthylazine, terbuthylazine, atrazine, atrazine-desethyl, bensulfuron-methyl, metobromuron, metribuzin, rotenone, pyriproxyfen, and rimsulfuron. In Lake Kerkini, mainly carbamates and triazines were determined at elevated concentrations, near the coastal point of the NW side of the lake. Seasonal variations were strong among the applied pesticide classes and determined concentrations, indicating the contribution of pesticide application patterns and rainfall. Lake Doirani exhibited organophosphate pesticides at higher concentrations mainly at coastal points, while triazines emerged as the main pollutant during spring sampling. Lake Volvi exhibited the highest pesticide concentrations, mostly triazines and ureas at the central part of the lake. The occurrence of extreme values and nonconstant seasonal variations indicated that the concentrations were increased disproportionately during the second sampling, as a result of the varying contribution of pollution sources right after the application period. In all cases, the total concentration of pesticides increased during the second sampling period. PMID:24696214

Kalogridi, Eleni-Chrysoula; Christophoridis, Christophoros; Bizani, Erasmia; Drimaropoulou, Garyfallia; Fytianos, Konstantinos

2014-06-01

356

Characterization of resistance to organophosphate, carbamate, and pyrethroid insecticides in field populations of Aedes aegypti from Venezuela.  

Science.gov (United States)

Resistance to the organophosphates (OP) temephos, malathion, and pirimiphos methyl, and the carbamate propoxur was found to be low (Falcon and Aragua states of Venezuela. Resistance to chlorpyrifos (OP), permethrin, and lambda-cyhalothrin (pyrethroids) was moderate (7-fold) in both populations. Mechanisms of resistance were investigated with the synergists piperonyl butoxide (mixed function oxidase inhibitor) and S, S, S-tributyl phosphorothioate (DEF, an esterase inhibitor). Nonspecific esterase and oxidase enzymes played a significant role in OP and carbamate resistance, respectively. Resistance to pyrethroid insecticides was not affected by DEF or piperonyl butoxide. This suggested the presence of another mechanism such as altered target site sensitivity (kdr). Biochemical tests showed significantly greater amounts of esterase activity in field strains, whereas insensitive acetylcholinesterase was not involved in either OP or carbamate resistance. These results must be considered in future control programs for Ae. aegypti, because OPs and pyrethroids are currently used in vector control in most countries of Central and South America. PMID:8551300

Mazzarri, M B; Georghiou, G P

1995-09-01

357

Effects of Two Carbamates on Infective Juveniles of Stemernema carpocapsae All Strain and Steinernema feltiae Ume? Strain  

Science.gov (United States)

Laboratory bioassays were conducted to determine the effects of two carbamates, carbofuran (an acetylcholinesterase inhibitor) and fenoxycarb (a juvenile hormone analog), on survival and infectivity of the infective juveniles (IJ) of Steinernema feltiae Umeå strain and Steinernema carpocapsae All strain. Both insecticides caused mortality of IJ in a dose-related fashion. The two nematode species were equally sensitive to fenoxycarb (LD?? ca. 0.03mg/ml). Whereas IJ of S. feltiae were several orders of magnitude more sensitive to carbofuran (LD?? ? 0.2 ?g/ml) than to fenoxycarb, S. carpocapsae IJ displayed approximately the same degree of sensitivity to carbofuran (LD?? 0.01-0.03 mg/ml) as they did toward fenoxycarb. Toxicity of the carbamates was the same at all exposure periods from 24 to 168 hours' duration. Determinations of infective doses of nematodes required to cause 50% mortality of Galleria mellonella larvae showed that the infectivity of IJ that survived exposure to either of the two carbamates was not compromised by treatment. PMID:19277148

Gordon, R.; Chippett, J.; Tilley, J.

1996-01-01

358

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

359

Challenges in Regulating Pesticide Mixtures  

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Full Text Available This paper introduces the field of mixture toxicity and the challenges in regulating pesticide mixtures. Even though pesticides are unique chemical stressors designed to have biological activity that can affect a number of nontarget species, they are intentionally placed into the environment in large quantities. Currently, methods and terminology for evaluating mixture toxicity are poorly established. The most common approach used is the assumption of additive concentration, with the concentrations adjusted for potency to a reference toxicant. Using this approach, the joint action of pesticides that have similar chemical structures and modes of toxic action can be predicted. However, this approach and other modeling techniques often provide little insight into the observed toxicity produced by mixtures of pesticides from different classes. Particularly difficult to model are mixtures that involve a secondary toxicant that changes the toxicokinetics of a primary toxicant. This may result in increased activation or a change in the persistence of the primary toxicant within the organism and may be responsible for a several-fold increase or decrease in toxicity. At present, the ecological effects caused by mixtures of pesticides are given little consideration in the regulatory process. However, mixtures are being considered in relation to human health in the pesticide registration process, setting a precedent that could be followed for ecological protection. Additionally, pesticide mixtures may be regulated through toxicity testing of surface water under the Clean Water Act. The limits of our basic knowledge of how mixtures interact are compromising both these avenues for regulating mixtures. We face many challenges to adequately protecting the environment from mixture toxicity; these challenges include understanding the interactions of toxicants within an organism, identifying the mixtures that most commonly occur and cause adverse effects, and developing a regulatory structure capable of minimizing environmental impacts.

Debra Denton

2004-12-01

360

Anticonvulsant properties of histamine H3 receptor ligands belonging to N-substituted carbamates of imidazopropanol.  

Science.gov (United States)

Ligands targeting central histamine H3 receptors (H3Rs) for epilepsy might be a promising therapeutic approach. Therefore, the previously described and structurally strongly related imidazole-based derivatives belonging to carbamate class with high H3R in vitro affinity, in-vivo antagonist potency, and H3R selectivity profile were investigated on their anticonvulsant activity in maximal electroshock (MES)-induced and pentylenetetrazole (PTZ)-kindled seizure models in Wistar rats. The effects of systemic injection of H3R ligands 1-13 on MES-induced and PTZ-kindled seizures were screened and evaluated against the reference antiepileptic drug (AED) Phenytoin (PHT) and the standard histamine H3R inverse agonist/antagonist Thioperamide (THP) to determine their potential as new antiepileptic drugs. Following administration of the H3R ligands 1-13 (5, 10 and 15 mg/kg, ip) there was a significant dose dependent reduction in MES-induced seizure duration. The protective action observed for the pentenyl carbamate derivative 4, the most protective H3R ligand among 1-13, was significantly higher (P <0.05) than that of standard H3R antagonist THP, and was reversed when rats were pretreated with the selective H3R agonist R-(?)-methyl-histamine (RAMH) (10mg/kg), or with the CNS penetrant H1R antagonist Pyrilamine (PYR) (10mg/kg). In addition, subeffective dose of H3R ligand 4 (5mg/kg, ip) significantly potentiated the protective action in rats pretreated with PHT (5mg/kg, ip), a dose without appreciable protective effect when given alone. In contrast, pretreatment with H3R ligand 4 (10mg/kg ip) failed to modify PTZ-kindled convulsion, whereas the reference drug PHT was found to fully protect PTZ-induced seizure. These results indicate that some of the investigated imidazole-based H3R ligands 1-13 may be of future therapeutic value in epilepsy. PMID:23891186

Sadek, Bassem; Shehab, Safa; Wi?cek, Ma?gorzata; Subramanian, Dhanasekaran; Shafiullah, Mohamed; Kie?-Kononowicz, Katarzyna; Adem, Abdu

2013-09-01

 
 
 
 
361

Precipitation of calcium carbonate from a calcium acetate and ammonium carbamate batch system  

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In this paper, we report a novel approach for preparing precipitated calcium carbonate using solutions of ammonium carbamate and calcium acetate as the sources of calcium and carbon dioxide, respectively. Two different concentrations of the starting solutions at three different temperatures (15, 25 and 50 °C) were used for the reaction. The influence of temperature and concentration on the polymorphism and the resulting morphology of calcium carbonate are discussed. The most important parameter for controlling a particular crystal structure and precipitate morphology were the concentrations of the initial solutions. When initial solutions with lower concentrations were used, the crystal form of the precipitate changed with time. Regardless the different polymorphism at different temperatures, after one day only the calcite form was detected in all samples, regardless of at which temperature the samples were prepared. At higher concentrations, pure vaterite or a mixture of vaterite and calcite were present at the beginning of the experiment. After one day, pure vaterite was found in the samples that were prepared at 15 and 25 °C. If calcium carbonate precipitated at 50 °C, the XRD results showed a mixture of calcite and vaterite regardless of the time at which the sample was taken. The morphology of calcium carbonate particles prepared at various conditions changed from calcite cubes to spherical particles of vaterite and aragonite needles. When a low starting concentration was used, the morphology at the initial stage was strongly affected by the temperature at which the experiments were conducted. However, after one day only, cubes were present in all cases at low initial concentrations. In contrast, at high concentrations spherical particles precipitated at all three temperatures at the beginning of the reaction. Spherical particles were made up from smaller particles. Over time, the size of the particles was diminishing due to their disintegration into primary particles; after one day, particles of 30-50 nm were obtained. The lower the temperature was during the experiment, the faster the larger particles fell apart. To our knowledge, this behavior has thus far not yet been reported. Moreover, for the first time ammonium carbamate and calcium acetate are used together to prepare calcium carbonate.

Prah, J.; Ma?ek, J.; Draži?, G.

2011-06-01

362

An applicable strategy for improvement recovery in simultaneous analysis of 20 pesticides residue in tea.  

Science.gov (United States)

It is important to have a reliable method to analyze pesticides in tea, a beverage commonly consumed in Iran. A validated method was developed for the determination of 20 pesticides in tea based on QuEChERS sample preparation and capillary gas chromatography-quadrupole mass spectrometry in selective ion monitoring mode (GC-MS/SIM) using triphenyl methane (TPM) solution as an internal standard. We used fortified, extracted, and cleaned-up tea samples instead of calibration standards for quantitation, which substantially reduced adverse matrix-related effects and negative recovery affected by graphite carbon black (GCB) on pesticide analysis. The recovery of pesticides at 3 concentration (40, 60, and 240 ng/g) ranged from 79.5% to 111.4% (n = 3). The method had acceptable repeatability with RSDr tea. PMID:23534490

Shoeibi, Shahram; Amirahmadi, Maryam; Rastegar, Hossein; Khosrokhavar, Roya; Khaneghah, Amin Mousavi

2013-05-01

363

Rapid multiresidue determination for currently used pesticides in agricultural drainage waters and soils using gas chromatography-mass spectrometry.  

Science.gov (United States)

An efficient and sensitive method for simultaneous determination of 38 pesticides in agricultural drainage waters and soils has been developed and validated. Water samples were extracted using solid-phase extraction with C18 cartridges while solid samples (suspended particle matter and soil) were extracted by using the quick, easy, cheap, effective, rugged and safe (QuEChERS) extraction method. The target pesticides were analyzed by using gas chromatography-mass spectrometry with electron impact ionization. The proposed method allowed a simultaneous determination and confirmation of a large number of pesticides in agricultural drainage waters, suspended particle matters and soils/sediments with a good reproducibility and low detection limits. The developed method was applied to a survey of pesticides in a vegetable growing area of Guangzhou, China. The pesticides commonly found in the area were butachlor, carbofuran, dichlorvos, fipronil, isocarbophos and pyridaben. PMID:20390945

Yang, Xiao-Bing; Ying, Guang-Guo; Kookana, Rai S

2010-02-01

364

33 CFR 274.4 - Pesticide management.  

Science.gov (United States)

...include information presented in the “Pesticide Applicator Training Manual”, § 274.3(e) or (2) a B.S. degree in agronomy, entomology, forestry or horticulture from an accredited college or university. (e) Restricted-use pesticide...

2010-07-01

365

Pesticide contamination of the coastline of Martinique  

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In January and February 2002, the presence of certain agricultural pesticides throughout the coastline of the Caribbean island of Martinique was investigated. The tropical climate of the French West Indies is suitable for banana production, which requires intensive use of pesticides. An inventory of all pesticides used on the island (compounds and tonnage) was compiled. Surveys and analyses revealed the presence of pesticides in the plumes of seven rivers. The organochlorine chlordecone and m...

Bocquene, Gilles; Franco, Alain

2005-01-01

366

Adapting LISEM to improve modeling of pesticide transfer by runoff and erosion  

Science.gov (United States)

Surface runoff and erosion represent major processes of pesticides transport from agricultural lands to aquatic ecosystems. Even if pesticide runoff models have been steadily improved in recent years, they remain only partially successful in correctly predicting pesticides transfers to surface waters. This could be partially explained by the limited ability to integrate (1) the spatial variability of pesticides deposition after application both on target and non-target areas, (2) the impact of rainfall variability within a storm event on the amount of pesticide transport and (3) the partitioning of pesticides between the aqueous and solid phases. The objective of this study is therefore to provide a simple modelling approach for pesticides mobilisation from the near surface soil layer. It may enable to identify the periods and source areas of contamination within a catchment. The Limburg Soil Erosion Model (LISEM) was chosen to develop this new pesticide module. This model is well designed to describe the agricultural landscape components and their impact on the runoff and erosion with high resolution rainfall data. LISEM is a fully distributed hydrological and soil erosion model that provides event-based predictions for agricultural plots and small catchments accounting for plant interception, surface storage in micro-depressions, soil detachment by rainfall, throughfall and runoff and the influence of tractor wheelings and paved roads. LISEM was validated for different soil and land use contexts. A simple mixing layer model was implemented to simulate the pesticide mobilisation at the soil/water interface and the partitioning between the dissolved and sorbed phases. This new model was applied on a 49 ha agricultural catchment with corns and sugar beets (Alsace, France). The output in terms of runoff, erosion and chloroacetanilides transport were compared to the data collected during an entire period of herbicide application from March to August 2012. A sensitivity analysis revealed that several key parameters influence the simulation results such as depth of the mixing zone and sorption coefficient.

Lefrancq, Marie; Jetten, Victor; Van Dijk, Paul; Payraudeau, Sylvain

2013-04-01

367

Organophosphate and carbamate poisonings in the northwest of Paraná state, Brazil from 1994 to 2005: clinical and epidemiological aspects Intoxicações por inseticidas organofosforados e carbamatos no noroeste do Paraná, Brasil, de 1994 a 2005: aspectos clínicos e epidemiológicos  

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Full Text Available In the present study, clinical and epidemiological aspects of 529 intoxication cases of organophosphate or carbamate pesticides in the northwest of the state of Paraná, Brazil, over a twelve-year period (1994-2005, are presented. One hundred-five of 257 patients (40.8% who attempted suicide were admitted to Intensive Care Units (ICUs, with an average hospital stay of two days (range 1-40 days. Men corresponded to 56.4% of the cases of suicide attempts and sixteen individuals died. One hundred-forty patients intoxicated due to occupational exposure were all young adults and nine of them were admitted to ICU, with average hospital stays of eight days (range 1-16 days. Of these cases, two patients died. One hundred twenty-four patients intoxicated due to accidental exposure were mainly children and had a hospital average stay of four days. Twenty patients were admitted to the ICU, and one of them died. Overall complications included respiratory failure, convulsions, and aspiration pneumonia. Deliberate ingestion of organophosphates and carbamates was much more toxic than occupational and accidental exposure. Men aged 15-39 years were the most likely to attempt suicide with these agents and had more prolonged ICU with significant complications and mortality.No presente estudo são apresentados aspectos clínicos e epidemiológicos de 529 casos de intoxicação por inseticidas organofosforados e carbamatos ocorridos na região noroeste do Estado do Paraná, Brasil, no período de 1994 a 2005. A saber, 105 pessoas de 257 pacientes (40,8% que tentaram suicídio foram admitidas na Unidade de Tratamento Intensivo (UTI, com média de estadia hospitalar de 2 dias (de 1 a 40 dias. Pacientes do sexo masculino corresponderam a 56,4% dos casos de tentativa de suicídio e 16 indivíduos morreram. Todos os 140 pacientes intoxicados devido à exposição ocupacional eram adultos e 9 foram admitidos na UTI, com média de estadia hospitalar de 8 dias (de 1 a 16 dias. Destes casos, 2 pacientes faleceram. Dos 124 pacientes intoxicados devido à exposição acidental, a maioria era crianças e teve uma média de estadia hospitalar de 4 dias. Foram admitidos 20 pacientes na UTI e um morreu. Complicações gerais incluíram insuficiência respiratória, convulsões e pneumonia. A ingestão deliberada de organofosforados e carbamatos foi muito mais grave do que a intoxicação em decorrência da exposição ocupacional ou acidental. Homens na faixa de 15 a 39 anos foram os mais prováveis de tentar suicídio com esses agentes e tiveram admissões mais prolongadas na UTI com significativas complicações e mortalidade.

Alexandre Ferreira

2008-09-01

368

Organophosphate and carbamate poisonings in the northwest of Paraná state, Brazil from 1994 to 2005: clinical and epidemiological aspects / Intoxicações por inseticidas organofosforados e carbamatos no noroeste do Paraná, Brasil, de 1994 a 2005: aspectos clínicos e epidemiológicos  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese No presente estudo são apresentados aspectos clínicos e epidemiológicos de 529 casos de intoxicação por inseticidas organofosforados e carbamatos ocorridos na região noroeste do Estado do Paraná, Brasil, no período de 1994 a 2005. A saber, 105 pessoas de 257 pacientes (40,8%) que tentaram suicídio f [...] oram admitidas na Unidade de Tratamento Intensivo (UTI), com média de estadia hospitalar de 2 dias (de 1 a 40 dias). Pacientes do sexo masculino corresponderam a 56,4% dos casos de tentativa de suicídio e 16 indivíduos morreram. Todos os 140 pacientes intoxicados devido à exposição ocupacional eram adultos e 9 foram admitidos na UTI, com média de estadia hospitalar de 8 dias (de 1 a 16 dias). Destes casos, 2 pacientes faleceram. Dos 124 pacientes intoxicados devido à exposição acidental, a maioria era crianças e teve uma média de estadia hospitalar de 4 dias. Foram admitidos 20 pacientes na UTI e um morreu. Complicações gerais incluíram insuficiência respiratória, convulsões e pneumonia. A ingestão deliberada de organofosforados e carbamatos foi muito mais grave do que a intoxicação em decorrência da exposição ocupacional ou acidental. Homens na faixa de 15 a 39 anos foram os mais prováveis de tentar suicídio com esses agentes e tiveram admissões mais prolongadas na UTI com significativas complicações e mortalidade. Abstract in english In the present study, clinical and epidemiological aspects of 529 intoxication cases of organophosphate or carbamate pesticides in the northwest of the state of Paraná, Brazil, over a twelve-year period (1994-2005), are presented. One hundred-five of 257 patients (40.8%) who attempted suicide were a [...] dmitted to Intensive Care Units (ICUs), with an average hospital stay of two days (range 1-40 days). Men corresponded to 56.4% of the cases of suicide attempts and sixteen individuals died. One hundred-forty patients intoxicated due to occupational exposure were all young adults and nine of them were admitted to ICU, with average hospital stays of eight days (range 1-16 days). Of these cases, two patients died. One hundred twenty-four patients intoxicated due to accidental exposure were mainly children and had a hospital average stay of four days. Twenty patients were admitted to the ICU, and one of them died. Overall complications included respiratory failure, convulsions, and aspiration pneumonia. Deliberate ingestion of organophosphates and carbamates was much more toxic than occupational and accidental exposure. Men aged 15-39 years were the most likely to attempt suicide with these agents and had more prolonged ICU with significant complications and mortality.

Alexandre, Ferreira; Elisangela, Maroco; Mauricio, Yonamine; Magda Lúcia Félix de, Oliveira.

369

Occurrence of pesticides from coffee crops in surface water / Ocorrência de agrotóxicos de culturas de café em águas superficiais  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese O excedente dos agrotóxicos aplicados nas áreas agrícolas pode atingir as águas superficiais, contaminando-as. Assim, o principal objetivo deste estudo foi investigar a presença dos agrotóxicos em águas superficiais e utilizadas para abastecimento público em uma sub-bacia de cabeceira, com cultivo d [...] e café, situada no distrito de Dom Corrêa em Manhuaçu, Minas Gerais. A região de estudo é grande produtora de café, as lavouras ocupam áreas íngremes e situam-se próximas aos cursos d´água. Para isso, foram selecionados quatro pontos de coletas de amostras de água nos córregos, um ponto na rede de distribuição e dois pontos na estação de tratamento (água bruta e tratada), totalizando sete pontos. As amostras foram coletadas em período chuvoso e seco. Agrotóxicos organoclorados, organofosforados, piretróides, carbamatos e triazóis foram constatados por meio de análise por cromatografia líquida e gasosa com espectrometria de massas em tandem. A ocorrência de agrotóxicos foi mais evidente no período chuvoso. Vinte e quatro agrotóxicos distintos foram detectados. Pelo menos um agrotóxico foi detectado em 67% das amostras coletadas, durante a estação chuvosa, e em 21% das amostras coletadas durante a estação seca. Muitos agrotóxicos detectados não estão relacionados na legislação brasileira de potabilidade. Abstract in english 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.

Alexandra Fátima Saraiva, Soares; Mônica Maria Diniz, Leão; Vanessa Heloisa Ferreira de, Faria; Márcia Cassimira Marcos da, Costa; Ana Clara Mourão, Moura; Vladimir Diniz Vieira, Ramos; Márcio Ribeiro, Vianna Neto; Elizângela Pinheiro da, Costa.

370

Occurrence of pesticides from coffee crops in surface water / Ocorrência de agrotóxicos de culturas de café em águas superficiais  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese O excedente dos agrotóxicos aplicados nas áreas agrícolas pode atingir as águas superficiais, contaminando-as. Assim, o principal objetivo deste estudo foi investigar a presença dos agrotóxicos em águas superficiais e utilizadas para abastecimento público em uma sub-bacia de cabeceira, com cultivo d [...] e café, situada no distrito de Dom Corrêa em Manhuaçu, Minas Gerais. A região de estudo é grande produtora de café, as lavouras ocupam áreas íngremes e situam-se próximas aos cursos d´água. Para isso, foram selecionados quatro pontos de coletas de amostras de água nos córregos, um ponto na rede de distribuição e dois pontos na estação de tratamento (água bruta e tratada), totalizando sete pontos. As amostras foram coletadas em período chuvoso e seco. Agrotóxicos organoclorados, organof