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

Energy Technology Data Exchange (ETDEWEB)

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

Owens, J; Koester, C

2008-05-14

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

OpenAIRE

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

Kiene, Ronald P.; Capone, Douglas G.

1986-01-01

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Effect of Cooking Process on the Residues of Three Carbamate Pesticides in Rice  

OpenAIRE

A gas chromatography mass spectrometry with spike calibration curve method was used to quantify three carbamate pesticides residue in cooked white rice and to estimate the reduction percentage of the cooking process duration.

Shoeibi, Shahram; Amirahmadi, Maryam; Yazdanpanah, Hassan; Pirali-hamedani, Morteza; Pakzad, Saied Reza; Kobarfard, Farzad

2011-01-01

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

Science.gov (United States)

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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Electrochemical detection of carbamate pesticides at conductive diamond electrodes.  

Science.gov (United States)

Conductive boron-doped diamond thin-film electrodes were used for the electrochemical detection of selected N-methylcarbamate pesticides (carbaryl, carbofuran, methyl 2-benzimidazolecarbamate, bendiocarb) after liquid chromatographic separation. Two kinds of detection methods were adopted in this study. In the first method, a direct detection of underivatized pesticides was carried out at an operating potential of 1.45 V versus Ag/AgCl, which resulted in the detection limits of 5-20 ng/mL (or 5-20 ppb) with S/N = 2 due to the low background current and wide potential window of the diamond electrode. In the second method, the detection limits were improved by subjecting the pesticide samples to alkaline hydrolysis in a separate step prior to injection. The phenolic derivatives obtained by alkaline hydrolysis oxidize at a relatively lower potential (0.9 V vs Ag/AgCl), which increases the sensitivity drastically. The advantage of the diamond electrode for the detection of phenolic derivatives is that it offers excellent stability in comparison to other electrodes. This method gives the detection limits of 0.6-1 ng/mL (or 0.6-1 ppb), which are well below the maximum residue levels allowed for carbaryl, carbofuran, and bendiocarb. While the lowest detection limits (LOD) obtained by the direct detection of pesticides are comparable to the those reported by the well-established HPLC-fluorescence, the LODs of the alkaline hydrolysis method are found to be even lower than the reported limits. On-line reactivation of the diamond electrode surface was shown to be possible by an anodic treatment of the electrode at approximately 3 V for 30 min in case of electrode fouling, which may occur after a prolonged use. Such a treatment damages the glassy carbon (GC) and metal electrodes, while the diamond electrode remains stable. These results suggest that the diamond electrode is superior to the other previously used electrodes such as GC and Kelgraf type for highly sensitive and stable detection of carbamate pesticides. PMID:12033247

Rao, Tata N; Loo, B H; Sarada, B V; Terashima, C; Fujishima, A

2002-04-01

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

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

Ogah C.O

2011-03-01

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

OpenAIRE

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

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

2011-01-01

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

OpenAIRE

In many countries, people are becoming more concerned about pesticide residues which are present in or on food and feed products. For this reason, several methods have been developed to monitor the pesticide residue levels in food samples. In this study, a bioactive paper-based sensor was developed for detection of acetylcholinesterase (AChE) inhibitors including organophosphate and carbamate pesticides. Based on the Ellman colorimetric assay, the assay strip is composed of a paper support (1...

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

2014-01-01

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Graphene-modified TiO2 nanotube arrays as an adsorbent in micro-solid phase extraction for determination of carbamate pesticides in water samples.  

Science.gov (United States)

Graphene is a good adsorbent for organic pollutants, especially for compounds containing benzene rings. When used in TiO2 nanotube arrays for micro-solid phase extraction (?-SPE), the combination of graphene's strong adsorptive properties with its good separation capabilities results in excellent sample preconcentration performance. In the present study, graphene-modified TiO2 nanotube arrays were prepared by electrodeposition using a cyclic voltammetric reduction method. Four carbamate pesticides, including metolcarb, carbaryl, isoprocarb, and diethofencarb, were used as model analytes to validate the enrichment properties of the prepared adsorbent in ?-SPE. Factors affecting the enrichment efficiency of the ?-SPE procedure were optimized and included sample pH, elution solvents, salting-out effect, adsorption time and desorption time. Under optimal conditions, graphene-modified TiO2 nanotube arrays exhibited excellent enrichment efficiency for carbamate pesticides. The detection limits of these carbamate pesticides ranged from 2.27 to 3.26?gL(-1). The proposed method was validated using four environmental water samples, and yields of pesticides recovered from spiked test samples of the four analytes were in the range of 83.9-108.8%. These results indicate that graphene-modified TiO2 nanotube arrays exhibit good adsorption to the target pollutants, and the method described in this work could be used as a faster and easier alternative procedure for routine analysis of carbamate pesticides in real water samples. PMID:25818138

Zhou, Qingxiang; Fang, Zhi

2015-04-15

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

Science.gov (United States)

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

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

Scientific Electronic Library Online (English)

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

Prapha, Arnnok; Rodjana, Burakham.

1720-17-01

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

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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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Medical treatment of acute poisoning with organophosphorus and carbamate pesticides.  

Science.gov (United States)

Organophosphorus compounds (OPs) are used as pesticides and developed as warfare nerve agents such as tabun, soman, sarin, VX and others. Exposure to even small amounts of an OP can be fatal and death is usually caused by respiratory failure. The mechanism of OP poisoning involves inhibition of acetylcholinesterase (AChE) leading to inactivation of the enzyme which has an important role in neurotransmission. AChE inhibition results in the accumulation of acetylcholine at cholinergic receptor sites, producing continuous stimulation of cholinergic fibers throughout the nervous systems. During more than five decades, pyridinium oximes have been developed as therapeutic agents used in the medical treatment of poisoning with OP. They act by reactivation of AChE inhibited by OP. However, they differ in their activity in poisoning with pesticides and warfare nerve agents and there is still no universal broad-spectrum oxime capable of protecting against all known OP. In spite of enormous efforts devoted to development of new pyridinium oximes as potential antidotes against poisoning with OP only four compounds so far have found its application in human medicine. Presently, a combination of an antimuscarinic agent, e.g. atropine, AChE reactivator such as one of the recommended pyridinium oximes (pralidoxime, trimedoxime, obidoxime and HI-6) and diazepam are used for the treatment of OP poisoning in humans. In this article the available data related to medical treatment of poisoning with OP pesticides are reviewed and the current recommendations are presented. PMID:19651196

Jokanovi?, Milan

2009-10-28

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

Science.gov (United States)

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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Pesticides.  

Science.gov (United States)

This review is devoted to methods for the determination of residues of pesticides and some related industrial chemicals. Topics include: residue methods, sampling, chromatography, organochlorine pesticides, organophosphorus pesticides, carbamate insecticides, herbicides, fungicides, pyrethrins, fumigants, and related chemicals. (MVL)

Sherma, Joseph

1989-01-01

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

Directory of Open Access Journals (Sweden)

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

IWUOHA E.

2013-01-01

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Direct gas chromatographic determination of carbamate pesticides using Carbowax 20M-modified supports and the electrolytic conductivity detector.  

Science.gov (United States)

The gas chromatographic behavior of 32 carbamate pesticides was investigated using the Hall electrolytic conductivity detector. Relative retention indices were successfully determined for 24 carbamates on six different columns. Columns investigated included Ultra-Bond, 3% OV-101 on Ultra-Bond, 1% OV-17 on Ultra-Bond, 1% OV-210 on Ultra Bond, 1% Carbowax 20M on Ultra-Bond and 0.5% OV-210 + 0.65% OV-17 on Ultra-Bond. Chemical-ionization gas chromatography-mass spectrometry was used to verify that the carbamates were chromatographed intact. Chemical-ionization mass spectra are reported. Analytical procedures are demonstrated for the determination of carbamate residue in soil. PMID:536418

Hall, R C; Harris, D E

1979-02-01

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

Energy Technology Data Exchange (ETDEWEB)

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

Kim, Byung Joo; So, Hun Young [Korea Research Institute of Standards and Sceince, Taejon (Korea, Republic of)

2000-05-01

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

Science.gov (United States)

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

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

2008-06-01

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

Science.gov (United States)

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

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

2013-09-15

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

Science.gov (United States)

A technique for multiplex detection of organophosphorus pesticides and carbamate pesticides has been developed using a suspension array based on silica-hydrogel hybrid microbeads (SHHMs). The main advantage of SHHMs, which consist of both silica and hydrogel materials, is that they not only could be distinguished by their characteristic reflection peak originating from the stop-band of the photonic crystal but also have low non-specific adsorption of proteins. Using fluorescent immunoassay, the LODs for fenitrothion, chlorpyrifos-methyl, fenthion, carbaryl and metolcarb were measured to be 0.02ng/mL, 0.012ng/mL, 0.04ng/mL, 0.05ng/mL and 0.1ng/mL, respectively, all of which are much lower than the maximum residue limits, as reported in the European Union pesticides database. All the determination coefficients for these five pesticides were greater than 0.99, demonstrating excellent correlations. The suspension array was specific and had no significant cross-reactivity with other chemicals. The results for the detection of pesticide residues collected from agricultural samples using this method agree well with those from liquid chromatography-tandem mass spectrometry. Our results showed that this simple method is suitable for simultaneous detection of these five pesticides residues in fruits and vegetables. PMID:24769809

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

2014-05-30

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

International Nuclear Information System (INIS)

Highlights: • Silica–hydrogel hybrid microbeads were used to develop suspension array. • The results in detecting pesticides agree well with those from LC–MS/MS. • The method showed the good capability for multiplex analysis of pesticides residues. - Abstract: A technique for multiplex detection of organophosphorus pesticides and carbamate pesticides has been developed using a suspension array based on silica–hydrogel hybrid microbeads (SHHMs). The main advantage of SHHMs, which consist of both silica and hydrogel materials, is that they not only could be distinguished by their characteristic reflection peak originating from the stop-band of the photonic crystal but also have low non-specific adsorption of proteins. Using fluorescent immunoassay, the LODs for fenitrothion, chlorpyrifos-methyl, fenthion, carbaryl and metolcarb were measured to be 0.02 ng/mL, 0.012 ng/mL, 0.04 ng/mL, 0.05 ng/mL and 0.1 ng/mL, respectively, all of which are much lower than the maximum residue limits, as reported in the European Union pesticides database. All the determination coefficients for these five pesticides were greater than 0.99, demonstrating excellent correlations. The suspension array was specific and had no significant cross-reactivity with other chemicals. The results for the detection of pesticide residues collected from agricultural samples using this method agree well with those from liquid chromatography–tandem mass spectrometry. Our results showed that this simple method is suitable for simultaneous detection of these five pesticides residues in fruits and vegetables

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Effects of organophosphate and carbamate pesticides on acetylcholinesterase and choline acetyltransferase activities of the polychaete Nereis diversicolor.  

Science.gov (United States)

A toxicity test for organophosphates (OP) and carbamates (C) was improved with the adult ragworm Nereis diversicolor. Animals were maintained in U-shaped glass tubes of 4-mm inner diameter fixed vertically on a plastic plate and placed in glass aquaria. Each tank was covered with glass in order to reduce evaporation and heat dissipation. Temperature varied between 15 and 16 degrees C and salinity was constant (34 per thousand) during the entire length of the experiment. Experiments were performed with a fixed day length of 12 h and seawater was gently aerated. The maintenance system allowed the administration of OP and C compounds via the seawater. An acclimatization period of 48 h was not sufficient to accomodate worms to their artificial burrows; accordingly, we chose to acclimate worms for a week before beginning the exposure. Choline acetyltransferase (ChAT) activity was very low and was not significantly modified by two OP compounds: malathion and parathion-ethyl. ChAT is not a target for these pesticides and should not be used for future studies about OP and C toxicity. On the other hand, inhibitory effects on acetylcholinesterase (AChE) activity were determined at concentrations of 10(-6) M for three OP compounds-malathion, parathion-ethyl, and phosalone-and a carbamate pesticide-carbaryl. We measured only short-term effects and no cumulative effect was determined, the maximum percentage of AChE activity inhibition being between 2 (carbaryl) and 7 (OP compounds) days after exposure and then remaining stable. Mortality occured only after a period of intoxication of 14 days. N diversicolor, which can be easily maintained at the laboratory, seems to be a good candidate for future laboratory studies to test the toxicity of other pollutants. PMID:9294250

Scaps, P; Demuynck, S; Descamps, M; Dhainaut, A

1997-08-01

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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

26

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

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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

27

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

28

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

29

Organophosphate and carbamate poisoning.  

Science.gov (United States)

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

King, Andrew M; Aaron, Cynthia K

2015-02-01

30

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.

31

Methods of analysis by the U.S. Geological Survey National Water Quality Laboratory; determination of selected carbamate pesticides in water by high-performance liquid chromatography  

Science.gov (United States)

As part of its primary responsibility concerning water as a national resource, the U.S. Geological Survey collects and analyzes samples of ground water and surface water to determine water quality. This report describes the method used since June 1987 to determine selected total-recoverable carbamate pesticides present in water samples. High- performance liquid chromatography is used to separate N-methyl carbamates, N-methyl carbamoyloximes, and an N-phenyl carbamate which have been extracted from water and concentrated in dichloromethane. Analytes, surrogate compounds, and reference compounds are eluted from the analytical column within 25 minutes. Two modes of analyte detection are used: (1) a photodiode-array detector measures and records ultraviolet-absorbance profiles, and (2) a fluorescence detector measures and records fluorescence from an analyte derivative produced when analyte hydrolysis is combined with chemical derivatization. Analytes are identified and confirmed in a three-stage process by use of chromatographic retention time, ultraviolet (UV) spectral comparison, and derivatization/fluorescence detection. Quantitative results are based on the integration of single-wavelength UV-absorbance chromatograms and on comparison with calibration curves derived from external analyte standards that are run with samples as part of an instrumental analytical sequence. Estimated method detection limits vary for each analyte, depending on the sample matrix conditions, and range from 0.5 microgram per liter to as low as 0.01 microgram per liter. Reporting levels for all analytes have been set at 0.5 microgram per liter for this method. Corrections on the basis of percentage recoveries of analytes spiked into distilled water are not applied to values calculated for analyte concentration in samples. These values for analyte concentrations instead indicate the quantities recovered by the method from a particular sample matrix.

Werner, S.L.; Johnson, S.M.

1994-01-01

32

The Stepwise Behavioral Responses: Behavioral Adjustment of the Chinese Rare Minnow (Gobiocypris rarus) in the Exposure of Carbamate Pesticides  

OpenAIRE

In order to illustrate the behavioral regulation in environmental stress, the behavioral responses of the Chinese rare minnow (Gobiocypris rarus) to arprocarb, carbofuran, and oxamyl were analyzed with an online monitoring system. The Self-Organizing Map (SOM) was used to define the patterns of the behavioral data obtained from treatments at concentrations of 0.1 toxic unit (TU), 1?TU, 2?TU, 5?TU, 10?TU, and 20?TU and a control. In certain cases, differences among the carbamate pest...

Mingsheng Miao; Liang Liu; Rongshu Fu; Zongming Ren

2013-01-01

33

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

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

Marcela Varona

2007-09-01

34

Summary of Validation of Multi-Pesticide Methods for Various Pesticide Formulations  

International Nuclear Information System (INIS)

The validation of multi-pesticide methods applicable for various types of pesticide formulations is treated. In a worked-out practical example, i.e. lambda cyhalothrin, the theoretical considerations outlined in the General Guidance section are put into practice. GC conditions, selection of an internal standard and criteria for an acceptable repeatability of injections are outlined, followed by sample preparation, calibration, batch analysis and confirmation of results through comparison using different separation columns. Complete sets of data are displayed in tabular form for other pesticide active ingredients and real formulations. (author)

35

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

Scientific Electronic Library Online (English)

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

Marcela, Varona; Gloria, Henao; Angélica, Lancheros; Álix, Murcia; Sonia, Díaz; Rocío, Morato; Ligia, Morales; Dyva, Revelo; Patricia, de Segurado.

2007-09-01

36

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

Science.gov (United States)

Prenatal pesticide exposures may adversely affect children's health. However, exposure and health research is hampered by the lack of reliable fetal exposure data. No studies have been published that report measurements of commonly used nonpersistent pesticides in human amniotic fluid, although recent studies of pesticides in urine from pregnant women and in meconium indicate that fetuses are exposed to these chemicals. Amniotic fluid collected during amniocentesis is the only medium available to characterize direct fetal exposures early in pregnancy (approximately 18 weeks of gestation). As a first step in validating this exposure biomarker, we collected 100 amniotic fluid samples slated for disposal and evaluated analytical methods to measure organophosphate and carbamate pesticides and metabolites, synthetic pyrethroid metabolites, herbicides, and chlorinated phenolic compounds. The following six phenols were detected (detection frequency): 1- and 2-naphthol (70%), 2,5-dichlorophenol (55%), carbofuranphenol (5%), ortho-phenylphenol (30%), and pentachlorophenol (15%), with geometric mean concentrations of 0.72, 0.39, 0.12, 0.13, and 0.23 microg/L, respectively, for positive values. The organophosphate metabolites diethylphosphate and dimethylphosphate were detected in two (10%) samples, and dimethylthiophosphate was detected in one (5%) sample, with geometric mean concentrations of 0.31, 0.32, and 0.43 microg/L, respectively, for positive values. These levels are low compared with levels reported in urine, blood, and meconium in other studies, but indicate direct exposures to the young fetus, possibly during critical periods of development. Results of this pilot study suggest that amniotic fluid offers a unique opportunity to investigate fetal exposures and health risks. PMID:14594631

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

2003-11-01

37

The validation of a pesticide exposure algorithm using biological monitoring results.  

Science.gov (United States)

A pesticide exposure algorithm was developed to calculate pesticide exposure intensity scores based on responses to questions about pesticide handling procedures and application methods in a self-administered questionnaire. The validity of the algorithm was evaluated through comparison of the algorithm scores with biological monitoring data from a study of 126 pesticide applicators who applied the herbicides MCPA or 2,4-D. The variability in the algorithm scores calculated for these applicators was due primarily to differences in their use of personal protective equipment (PPE). Rubber gloves were worn by 75% of applicators when mixing and 22% when applying pesticides, rubber boots were worn by 33% when mixing and 23% when applying, and goggles were worn by 33% and 17% of applicators when mixing and when applying, respectively. Only 2% of applicators wore all three types of PPE when both mixing and applying, and 15% wore none of these three types of PPE when either mixing or applying. Substantial variability was also observed in the concentrations of pesticides detected in the post application urine samples. The concentration of MCPA detected in urine samples collected on the second day after the application ranged from less than categories for both the 2,4-D and the MCPA applicators. The algorithm scores, based primarily on the use of PPE, appear to provide a reasonably valid measure of exposure intensity for these applicators, however, further studies are needed to generalize these results to other types of pesticides and application methods. PMID:15764542

Coble, Joseph; Arbuckle, Tye; Lee, Wonjin; Alavanja, Michael; Dosemeci, Mustafa

2005-03-01

38

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

International Nuclear Information System (INIS)

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

39

Development and validation of a multiresidue method for the analysis of 151 pesticide residues in strawberry by gas chromatography coupled to a triple quadrupole mass analyzer.  

Science.gov (United States)

A new method was developed and validated for the simultaneous determination of 151 pesticide residues in strawberry by gas chromatography coupled to a triple quadrupole mass analyzer (GC/QqQ-MS/MS), mainly using the selected reaction monitoring (SRM) mode. The list of target compounds included various classes of pesticides such as organochlorine (OCPs), organophosphorus (OPPs), carbamates, pyrethroids, triazoles and dicarboximides. A single extraction of 10 g of sample with acetonitrile followed by liquid-liquid partition formed by the addition of 4 g of MgSO4 and 1 g of NaCl was applied in sample preparation. Cleanup of the extracts was carried out by applying dispersive solid-phase extraction (D-SPE) with primary secondary amine (PSA). The analysis time was 21 min. The method was subjected to a thorough validation procedure. The recovery data were obtained by spiking blank samples at two concentration levels (11.5 and 50 microg/kg), yielding recoveries in the range 70-110%. Precision values expressed as relative standard deviation (RSD) were lower than 18% and 22% for the intraday and interday precision, respectively. Linearity was studied in the range 10-200 microg/kg and determination coefficients (R(2)) were higher than 0.98% for all compounds. Limits of detection (LODs) and limits of quantification (LOQs) were established as 4 and 10 microg/kg, respectively. The overall uncertainty of the method was estimated at two different concentrations (11.5 and 50 microg/kg), being lower than 25% in both cases. According to the validation data and performance characteristics as well as the high sample throughput and low cost, the proposed method is suitable for routine application. PMID:17577875

Bolaños, Patricia Plaza; Moreno, José Luis Fernández; Shtereva, Deyana D; Frenich, Antonia Garrido; Vidal, José Luis Martínez

2007-01-01

40

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

OpenAIRE

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

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

2012-01-01

41

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

42

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

Science.gov (United States)

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

43

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

OpenAIRE

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

Mladenova, Rositsa; Shtereva, Deyana

2009-01-01

44

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.

45

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)

46

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

Science.gov (United States)

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

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

2015-04-01

47

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

48

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

49

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

50

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.

51

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

52

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

Scientific Electronic Library Online (English)

Full Text Available 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

53

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

54

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)

55

Validation and application of micro flow liquid chromatography-tandem mass spectrometry for the determination of pesticide residues in fruit jams.  

Science.gov (United States)

In this study, a very sensitive method was validated to determine pesticides residues in fruit jams using micro flow liquid chromatography-tandem mass spectrometry (µLC-MS/MS). A slurry of the fruit jams and water was prepared to yield homogeneous samples. Because of the high sensitivity achieved with the µLC-MS/MS equipment and to minimize matrix effects, the QuEChERS extracts were diluted 30-fold before the analysis. The validation was performed analyzing spiked samples at 9 and 45 µg kg(-1) (n=5). The method met validation criteria of 70-120% recovery and RSD?20% for 92% of the 107 pesticides evaluated. The reporting limit (RL) was 9 and 45 µg kg(-1) for respectively 66% and 26% of the analytes, 5% of the compounds did not fulfill the requirements for validation and 3% were not detected at the studied concentrations. The validated method was applied to the analysis of 51 different fruit jam samples from Brazil and Spain and pesticide residues were detected in 41 samples, 26 of which contained at least one pesticide at concentration >10 µg kg(-1). PMID:25618688

Reichert, Bárbara; Pizzutti, Ionara Regina; Costabeber, Ijoni Hilda; Uclés, Ana; Herrera, Sonia; Fernández-Alba, Amadeo R

2015-03-01

56

[Neurotoxicology of pesticides].  

Science.gov (United States)

Pesticides have been used for many years for preventing, destroying, repelling, or mitigating pests such as insects, rodents, and weeds. However, most pesticides are not completely specific for pests and can also induce damage to the human nervous system. In particular, insecticides often directly targets the nervous system by affecting major targets such as the neuro-transmitter metabolism, neuronal receptors, and ion channels; acetylcholine (ACh) esterase for organo-phosphates and carbamates, nicotinic ACh receptor for neonicotinoids, ?-aminobutyric acid receptors/chloride channels for organochlorides and fipronil, and voltage-gated sodium channel for pyrethroids. Additional targets include sites in the sodium channels, glutamate-gated chloride channels, and octopamine and ryanodine receptors. Several pesticides also produce adverse neurological effects indirectly by disrupting the general cellular mechanisms that support the high metabolic activity of the nervous system. Nowadays, more potent pesticides are being developed as replacements for the older, harmful ones. Pesticide neurotoxicity in humans may involve the central or peripheral nervous system or both and may induce typical neuronal damage in case of acute poisoning even by new agents. However, whether effect of exposure to pesticides at below acute-poisoning threshold level remains unclear. Moreover, neurotoxicology for behavioral and higher-brain function remains an unresolved and a challenging problem. PMID:25585434

Ichikawa, Hiroo

2015-01-01

57

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

Scientific Electronic Library Online (English)

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

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

2004-12-01

58

Validation and uncertainty assessment of rapid extraction and clean-up methods for the determination of 16 organochlorine pesticide residues in vegetables.  

Science.gov (United States)

Rapid and practical extraction methods were developed using dichloromethane and ethyl acetate for the routine determination of 16 organochlorine pesticide residues and applied to approximately 30 fresh vegetables (tomato, cucumber and pepper) by using GC-ECD. The procedures were validated. Measurement uncertainties were calculated by applying bottom-up approach. The average recoveries obtained for each pesticide ranged between 65 and 102% at three fortification levels. The uncertainties of the analytical methods were lower than 21 and 16% with and without recovery correction, respectively. The calculated limits of detection and quantification were typically less than 1 ng g(-1) that were much lower than the maximum residue levels. PMID:17723451

Yenisoy-Karaka?, Serpil

2006-07-01

59

The heterogeneous ozonation of pesticides adsorbed on mineral particles: Validation of the experimental setup with trifluralin  

Science.gov (United States)

In this study, an experimental device adapted for the investigation of organic compounds with both low and high reactivity towards gaseous ozone is presented. The heterogeneous reactions were performed in a round-bottom flask connected to a rotary evaporator specially adapted to this purpose. The extract of the remaining compound on silica particles was filtered and analysed using High Pressure Liquid Chromatography with a UV detector. The kinetic was determined by following the consumption of the organic (dark, T = 26 °C, RH atmosphere and lead to the formation of adsorbed degradation products. Moreover, our kinetic constants are in reasonable agreement (factor 3) to the one obtained in the previous study using flow tubes. Finally, our simple alternative device offers the possibility of increasing the number of heterogeneous process investigations, which constitutes an absolute necessity for issues of the environmental fate of pesticides.

Pflieger, Maryline; Grgi?, Irena; Kitanovski, Zoran; Nieto, Laura; Wortham, Henri

2011-12-01

60

Types of pesticides and determination of their residues  

International Nuclear Information System (INIS)

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

61

Validation of a method using solid phase extraction and liquid chromatography for the determination of pesticide residues in groundwaters  

Scientific Electronic Library Online (English)

Full Text Available Neste trabalho, um método para determinação dos agrotóxicos carbofurano, clomazona, 2,4-D e tebuconazol em águas subterrâneas é descrito. O método utiliza a Extração em Fase Sólida (EFS) com cartuchos de C18 e quantificação por Cromatografia Líquida de Alta eficiência com Detector de Arranjo de Diod [...] os (CLAE-DAD). Após a otimização dos parâmetros de extração e separação dos compostos, o método foi validado avaliando-se curva analítica, linearidade, limites de detecção e quantificação, precisão e exatidão (recuperação). O método apresentou recuperações médias de 87,9% e 96,9%, para a repetibilidade e precisão intermediária, respectivamente, com RSD de 0,8 a 20,7% para todos os compostos. O método será empregado na determinação de agrotóxicos em águas subterrâneas com um limite de quantificação de 0,2 ?g L-1. Abstract in english A method is described for the determination of the pesticides carbofuran, clomazone, 2,4-D and tebuconazole in groundwaters. The method involves solid phase extraction (SPE) with C18 cartridges and quantification by high performance liquid chromatography with diode array detector (HPLC-DAD). After t [...] he optimization of the extraction and separation parameters, the method was validated by evaluating the analytical curve, linearity, limits of detection and quantification, precision and accuracy (recovery). The method presents an average recovery of 87.9% and 96.9%, in repeatability and intermediate precision conditions, respectively, with adequate precision (RSD from 0.8 to 20.7%), for all compounds. The method will be applied to determine pesticides in groundwater samples with limit of quantification of 0.2 ?g L-1.

Sergiane S., Caldas; Adriana, Demoliner; Ednei G., Primel.

62

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

63

Use of experimental designs for the optimization of stir bar sorptive extraction coupled to GC-MS/MS and comprehensive validation for the quantification of pesticides in freshwaters.  

Science.gov (United States)

Although experimental design is a powerful tool, it is rarely used for the development of analytical methods for the determination of organic contaminants in the environment. When investigated factors are interdependent, this methodology allows studying efficiently not only their effects on the response but also the effects of their interactions. A complete and didactic chemometric study is described herein for the optimization of an analytical method involving stir bar sorptive extraction followed by thermal desorption coupled with gas chromatography and tandem mass spectrometry for the rapid quantification of several pesticides in freshwaters. We studied, under controlled conditions, the effects of thermal desorption parameters and the effects of their interactions on the desorption efficiency. The desorption time, temperature, flow, and the injector temperature were optimized through a screening design and a Box-Behnken design. The two sequential designs allowed establishing an optimum set of conditions for maximum response. Then, we present the comprehensive validation and the determination of measurement uncertainty of the optimized method. Limits of quantification determined in different natural waters were in the range of 2.5 to 50 ng L(-1), and recoveries were between 90 and 104 %, depending on the pesticide. The whole method uncertainty, assessed at three concentration levels under intra-laboratory reproducibility conditions, was below 25 % for all tested pesticides. Hence, we optimized and validated a robust analytical method to quantify the target pesticides at low concentration levels in freshwater samples, with a simple, fast, and solventless desorption step. PMID:24493337

Assoumani, A; Margoum, C; Guillemain, C; Coquery, M

2014-04-01

64

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

OpenAIRE

Terrestrial snails are destructive agricultural pests as they cause a great damage to vegetables and crops. The present study was designed to evaluate the toxic action of two carbamate molluscicides, methomyl and methiocarb on the digestive gland of the land snail E. vermiculata which is the main site of accumulation and biotransformation of xenobiotics, using topical application and baiting techniques. Sublethal doses and concentrations of both pesticides were applied. After 1, 3, 5, 7 and 1...

Hamed, Sherifa S.; Abdelmeguied, Nabila E.; Essawy, Amina E.; Radwan, Mohamed A.; Hegazy, Amira E.

2007-01-01

65

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

OpenAIRE

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

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

2003-01-01

66

Development, validation, and uncertainty measurement of multi-residue analysis of organochlorine and organophosphorus pesticides using pressurized liquid extraction and dispersive-SPE techniques.  

Science.gov (United States)

Simple and efficient multi-residue analytical methods were developed and validated for the determination of 13 organochlorine and 17 organophosphorous pesticides from soil, spinach and eggplant. Techniques namely accelerated solvent extraction and dispersive SPE were used for sample preparations. The recovery studies were carried out by spiking the samples at three concentration levels (1 limit of quantification (LOQ), 5 LOQ, and 10 LOQ). The methods were subjected to a thorough validation procedure. The mean recovery for soil, spinach and eggplant were in the range of 70-120% with median CV (%) below 10%. The total uncertainty was evaluated taking four main independent sources viz., weighing, purity of the standard, GC calibration curve and repeatability under consideration. The expanded uncertainty was well below 10% for most of the pesticides and the rest fell in the range of 10-20%. PMID:21210211

Sanyal, Doyeli; Rani, Anita; Alam, Samsul; Gujral, Seema; Gupta, Ruchi

2011-11-01

67

[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

68

Using phylogenetic information and chemical properties to predict species tolerances to pesticides.  

Science.gov (United States)

Direct estimation of species' tolerance to pesticides and other toxic organic substances is a combinatorial problem, because of the large number of species-substance pairs. We propose a statistical modelling approach to predict tolerances associated with untested species-substance pairs, by using models fitted to tested pairs. This approach is based on the phylogeny of species and physico-chemical descriptors of pesticides, with both kinds of information combined in a bilinear model. This bilinear modelling approach predicts tolerance in untested species-compound pairs based on the facts that closely related species often respond similarly to toxic compounds and that chemically similar compounds often have similar toxic effects. The three tolerance models (median lethal concentration after 96 h) used up to 25 aquatic animal species and up to nine pesticides (organochlorines, organophosphates and carbamates). Phylogeny was estimated using DNA sequences, while the pesticides were described by their mode of toxic action and their octanol-water partition coefficients. The models explained 77-84% of the among-species variation in tolerance (log10 LC50). In cross-validation, 84-87% of the predicted tolerances for individual species were within a factor of 10 of the observed values. The approach can also be used to model other species response to multivariate stress factors. PMID:25009056

Guénard, Guillaume; Carsten von der Ohe, Peter; Carlisle Walker, Steven; Lek, Sovan; Legendre, Pierre

2014-08-22

69

Phenyl N-(2-methylphenyl)carbamate  

OpenAIRE

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

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

2009-01-01

70

Role of individual susceptibility in risk assessment of pesticides  

OpenAIRE

OBJECTIVES: This study presents criteria for assessing the individual pesticide burden of workers in the chemical industry. METHODS: A group of 1003 workers exposed to methylparathion or ethylparathion (alkyl phosphates), propoxur (carbamate), or cyfluthrin (pyrethroid) was investigated. After exposure to methylparathion or ethylparathion the methylparathion or ethylparathion and methylparaoxon or ethylparaoxon concentrations in plasma, the p-nitrophenol concentration in urine, and the ...

Leng, G.; Lewalter, J.

1999-01-01

71

Validation and application of an analytical method for determining pesticides in the gas phase of ambient air.  

Science.gov (United States)

A method for determining atmospheric concentrations of eight pesticides applied to corn and soybean crops in Mato Grosso state, Brazil is presented. The method involved a XAD-2 resin cartridge coupled to a low volume air pump at 2 L min?¹ over 8 hours. Pesticides were recovered from the resin using sonication with n-hexane:ethyl acetate and determined by GC-MS. Good accuracy (76-128%) and precision (CV flutriafol, malathion, metolachlor and permethrin. Method detection ranged from 9.0 to 17.9 ng m?³. This method was applied to 61 gas phase samples collected between December 2008 and June 2009. Atrazine and endosulfan were detected both in urban and rural areas indicating the importance of atmospheric dispersion of pesticides in tropical areas. The simple and efficient extraction method and sampling system employed was considered suitable for identifying pesticides in areas of intense agricultural production. PMID:21328123

Dos Santos, Luciane G; Lourencetti, Carolina; Pinto, Alicio A; Pignati, Wanderlei A; Dores, Eliana F G C

2011-01-01

72

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

OpenAIRE

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

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

2009-01-01

73

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

OpenAIRE

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...

Eloisa Dutra Caldas; Bruno Zago Diniz; Juciê Roniery Silva; Juliana Oliveira Pasiani; Priscila Torres

2012-01-01

74

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

75

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

Energy Technology Data Exchange (ETDEWEB)

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)

Hadjel, M.; Berkok, N.

2009-07-01

76

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)

77

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

78

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

79

Validation of an Efficient Method for the Determination of Pesticide Residues in Fruits and Vegetables Using Ethyl Acetate for Extraction  

Science.gov (United States)

In this study, a version of the “quick, easy, cheap, effective, rugged, and safe” (QuEChERS) method was modified to use ethyl acetate (EtOAc) rather than acetonitrile (MeCN) for extraction in the determination of multiple pesticide residues in fruits and vegetables. EtOAc is better suited than MeCN...

80

75 FR 11174 - Pesticide Product Registration Approval  

Science.gov (United States)

...20737, to register the pesticide product, Gonacon Immunocontraceptive...of use, application methods and rates, and level...1700--Validating the method of analysis of the formulation and...application to register the pesticide product, Gonacon...

2010-03-10

81

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

82

Pesticide residues in apples grown under a conventional and integrated pest management system.  

Science.gov (United States)

This paper describes method validation for determination of more than 40 pesticides in apples using a GC technique. Target compounds belonged to the organochlorine, organophosphorus, carbamates, pyrethroids, triazoles, dicarboximides and strobilurins groups, among others. Sample preparation consisted of acetone extraction and subsequent cleanup/concentration by SPE with a polymer-based sorbent. Single quadrupole GC-MS operating in SIM mode and electron impact ionization was used for identification and quantification of the pesticides. Average recoveries for analytes ranged between 70 and 110% at three fortification levels - 0.01, 0.1 and 0.2 mg kg(-1). Relative standard deviations were lower than 20% for all tested compounds. Calculated limits of detection and limits of quantification were below 0.01 mg kg(-1), which were sufficiently low compared to the maximum residue levels (MRLs) established by European legislation. The proposed method was applied for determination of pesticide residue in four selected apple varieties after harvesting. Whole and processed fruits (peel and peeled fruits) were analyzed from different treatment systems: two conventional, one based on integrated pest management (IPM) and two variants based on organic production (controls). Higher levels of pesticide residues were found in apple fruits under conventional conditions. Fenitrothion and chlorpyrifos residues were detected frequently in apple peel at concentrations up to 0.45 and 0.77 mg kg(-1), respectively. The levels found in the whole fruits of the same samples were much lower than in peel and below the respective MRLs (0.5 mg kg(-1) for both pesticides). Measurable residues of triadimenol only, up to 0.05 mg kg(-1), concentrated in the peel, were found in the apples from IPM. PMID:19680960

Mladenova, R; Shtereva, D

2009-06-01

83

Automated determination of ethyl carbamate in stone-fruit spirits using headspace solid-phase microextraction and gas chromatography-tandem mass spectrometry.  

Science.gov (United States)

A fully automated procedure using headspace solid-phase microextraction (HS-SPME) followed by gas chromatographic/tandem mass spectrometric (GC/MS/MS) detection was developed for the determination of the toxic contaminant ethyl carbamate (EC) in stone-fruit spirits. After addition of deuterated internal standard, the optimised HS-SPME extraction with carbowax/divinylbenzene fibres (30 min at 70 degrees C) was done applying salting out with sodium chloride in the presence of pH 7 buffer solution. For quantitative analysis the characteristic fragmentations of m/z 74>44 and m/z 62>44 for ethyl carbamate as well as m/z 64>44 for ethyl carbamate-d5 were monitored in the multiple reaction monitoring (MRM) mode using a triple quadrupole instrument. In the validation studies, ethyl carbamate exhibited good linearity with a regression coefficient of 0.998. The limits of detection and quantitation were 0.03 and 0.11 mg/l. The precision never exceeded 4.3% (intraday) and 8.2% (interday) at any of the concentrations examined. A good agreement of analysis results in comparison to conventional sample clean-up over diatomaceous earth columns was found (R = 0.956, Bias = 0.08 mg/l). The new HS-SPME/GC/MS/MS procedure is suitable for the fast, reliable and inexpensive determination of ethyl carbamate in alcoholic beverages in an automated, and therefore, convenient procedure. PMID:16427646

Lachenmeier, Dirk W; Nerlich, Uta; Kuballa, Thomas

2006-03-01

84

Evaluation and validation of an accurate mass screening method for the analysis of pesticides in fruits and vegetables using liquid chromatography-quadrupole-time of flight-mass spectrometry with automated detection.  

Science.gov (United States)

This study reports the development and validation of a screening method for the detection of pesticides in 11 different fruit and vegetable commodities. The method was based on ultra performance liquid chromatography-quadrupole-time of flight-mass spectrometry (UPLC-QTOF-MS). The objective was to validate the method in accordance with the SANCO guidance document (12571/2013) on analytical quality control and validation procedures for pesticide residues analysis in food and feed. Samples were spiked with 199 pesticides, each at two different concentrations (0.01 and 0.05 mg kg(-1)) and extracted using the QuEChERS approach. Extracts were analysed by UPLC-QTOF-MS using generic acquisition parameters. Automated detection and data filtering were performed using the UNIFI™ software and the peaks detected evaluated against a proprietary scientific library containing information for 504 pesticides. The results obtained using different data processing parameters were evaluated for 4378 pesticide/commodities combinations at 0.01 and 0.05 mg kg(-1). Using mass accuracy (± 5 ppm) with retention time (± 0.2 min) and a low response threshold (100 counts) the validated Screening Detection Limits (SDLs) were 0.01 mg kg(-1) and 0.05 mg kg(-1) for 57% and 79% of the compounds tested, respectively, with an average of 10 false detects per sample analysis. Excluding the most complex matrices (onion and leek) the detection rates increased to 69% and 87%, respectively. The use of additional parameters such as isotopic pattern and fragmentation information further reduced the number of false detects but compromised the detection rates, particularly at lower residue concentrations. The challenges associated with the validation and subsequent implementation of a pesticide multi-residue screening method are also discussed. PMID:25465001

López, Mónica García; Fussell, Richard J; Stead, Sara L; Roberts, Dominic; McCullagh, Mike; Rao, Ramesh

2014-12-19

85

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

OpenAIRE

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

86

Development, validation and application of a time-dependent food web bioaccumulation model for organic pesticides in aquatic ecosystems  

OpenAIRE

Currently, steady-state based bioaccumulation models are used by regulators to assist environmental guideline development and to conduct legislation of pesticides. For high Kow chemicals that do not reach steady-state in environmental compartments quickly, the steady-state based models could overestimate chemical concentrations and lead to errors in environmental evaluation. A time-dependent food web bioaccumulation model was developed to improve the evaluation of the fate and effects of pest...

Lai, Hao-feng

2010-01-01

87

Interference modelling, experimental design and pre-concentration steps in validation of the Fenton's reagent for pesticides determination.  

Science.gov (United States)

The determination of atrazine in real samples (commercial pesticide preparations and water matrices) shows how the Fenton's reagent can be used with analytical purposes when kinetic methodology and multivariate calibration methods are applied. Also, binary mixtures of atrazine-alachlor and atrazine-bentazone in pesticide preparations have been resolved. The work shows the way in which interferences and the matrix effect can be modelled. Experimental design has been used to optimize experimental conditions, including the effect of solvent (methanol) used for extraction of atrazine from the sample. The determination of pesticides in commercial preparations was accomplished without any pre-treatment of sample apart from evaporation of solvent; the calibration model was developed for concentration ranges between 0.46 and 11.6 x 10(-5) mol L(-1) with mean relative errors under 4%. Solid-phase extraction is used for pre-concentration of atrazine in water samples through C(18) disks, and the concentration range for determination was established between 4 and 115 microg L(-1) approximately. Satisfactory results for recuperation of atrazine were always obtained. PMID:17386609

Ostra, Miren; Ubide, Carlos; Zuriarrain, Juan

2007-02-12

88

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

OpenAIRE

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

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

2007-01-01

89

Radiotracer Approaches to Carbamate Insecticide Toxicology  

International Nuclear Information System (INIS)

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

90

Carbamate kinase: New structural machinery for making carbamoyl phosphate, the common precursor of pyrimidines and arginine.  

OpenAIRE

The enzymes carbamoyl phosphate synthetase (CPS) and carbamate kinase (CK) make carbamoyl phosphate in the same way: by ATP-phosphorylation of carbamate. The carbamate used by CK is made chemically, whereas CPS itself synthesizes its own carbamate in a process involving the phosphorylation of bicarbonate. Bicarbonate and carbamate are analogs and the phosphorylations are carried out by homologous 40 kDa regions of the 120 kDa CPS polypeptide. CK can also phosphorylate bicarbonate and is a hom...

Marina, A.; Alzari, P. M.; Bravo, J.; Uriarte, M.; Barcelona, B.; Fita, I.; Rubio, V.

1999-01-01

91

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

Science.gov (United States)

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

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

2014-09-01

92

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

93

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

94

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)

95

Acetylcholinesterase Based Detection of Residual Pesticides on Cotton  

OpenAIRE

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-elec...

Jiri Militky; Syed Zameer Ul Hassan

2012-01-01

96

Silver nanoparticle-based chemiluminescent sensor array for pesticide discrimination.  

Science.gov (United States)

In this work, we developed a simple, facile, and highly sensitive nanoparticle-based chemiluminescent (CL) sensor array for the discrimination of organophosphate and carbamate pesticides. This CL sensor array is based on simultaneous utilization of the triple-channel properties of the luminol-functionalized silver nanoparticle (Lum-AgNP) and H2O2 CL system containing CL intensity, the time for CL emissions to appear, and the time to reach the CL peak value, which are able to be measured via a single experiment. The triple-channel properties can be simultaneously altered after interaction with pesticides, producing distinct CL response patterns as "fingerprints" related to each specific pesticide, which was subjected to principal component analysis (PCA) to generate a clustering map. Using this sensor array, five organophosphate and carbamate pesticides, including dimethoate, dipterex, carbaryl, chlorpyrifos, and carbofuran, have been well-distinguished at a concentration of 24 ?g/mL. A total of 20 unknown pesticide samples have been successfully identified with an accuracy of 95%. The simple strategy of this study is expected to promote the development of functionalized nanomaterial-based sensor arrays. PMID:25751408

He, Yi; Xu, Bo; Li, Wenhao; Yu, Haili

2015-03-25

97

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

Science.gov (United States)

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

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

2012-04-01

98

Time-response necessary in validation for extraction of pesticides from cloth patches used in field exposure studies.  

Science.gov (United States)

Environmental exposure in field studies is generally monitored by the cloth patch technique. Many investigators question the accuracy of the technique, in part due to lack of validation. The objective was to examine extraction of chemicals from cloth patches for potential technique validation. Chemicals studied were glyphosate, atrazine, malathion, alachlor and 2,4-dichlorophenoxy acetic acid (2,4-D), a selection of hydrophilic (glyphosate) and varying lipophilic compounds. The 14C-radiolabeled chemical was applied to a cotton patch (two types used) and solvent extracted over a 48-h time period. The chemical was soluble in the application solvent and in the extraction solvent. Extraction was near 100% at time 0 h, but statistically (P residue and accountability was always excellent. The chemicals exhibited a time-response by incorporating into the cotton patch and not being available for extraction. Thus, validation of the cloth patch technique must include the time-period from the start of a field trial until laboratory analysis, a process which can take several days. This may account in part for differences noted between cloth patch technique and biological monitoring. It was subsequently shown that sonication loosens chemicals incorporated in the cloth patch, making the chemicals available for extraction. That sonication dislodged the chemicals suggests that the chemicals were not chemically bonded within the fabric but were probably sequestered within the fabric away from the solvent. PMID:8060174

Wester, R C; Melendres, J; Serranzana, S; Maibach, H I

1994-08-01

99

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

Science.gov (United States)

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

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

2014-04-01

100

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

101

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

102

The Pesticide Action Network Pesticide Database  

Science.gov (United States)

The Pesticide Action Network Pesticide Database, maintained by the Pesticide Action Network of North America, provides up-to-date information for those working with or researching pesticides. The site lets users search by chemical name, chemical abstracts service (CAS) number, trade name, or US EPA product registration number to retrieve a selected pesticide's active ingredients, breakdown products, and other chemicals used in it. Also available is California specific pesticide information, toxicity and regulation information, nontoxic alternatives to pesticides, and more.

103

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

Science.gov (United States)

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

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

2014-10-22

104

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

OpenAIRE

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

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

2012-01-01

105

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

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

Lacassie Éric

2009-04-01

106

Cross validation of gas chromatography-flame photometric detection and gas chromatography-mass spectrometry methods for measuring dialkylphosphate metabolites of organophosphate pesticides in human urine.  

Science.gov (United States)

We report two analytical methods for the measurement of dialkylphosphate (DAP) metabolites of organophosphate pesticides in human urine. These methods were independently developed/modified and implemented in two separate laboratories and cross validated. The aim was to develop simple, cost effective, and reliable methods that could use available resources and sample matrices in Thailand and the United States. While several methods already exist, we found that direct application of these methods required modification of sample preparation and chromatographic conditions to render accurate, reliable data. The problems encountered with existing methods were attributable to urinary matrix interferences, and differences in the pH of urine samples and reagents used during the extraction and derivatization processes. Thus, we provide information on key parameters that require attention during method modification and execution that affect the ruggedness of the methods. The methods presented here employ gas chromatography (GC) coupled with either flame photometric detection (FPD) or electron impact ionization-mass spectrometry (EI-MS) with isotopic dilution quantification. The limits of detection were reported from 0.10ng/mL urine to 2.5ng/mL urine (for GC-FPD), while the limits of quantification were reported from 0.25ng/mL urine to 2.5ng/mL urine (for GC-MS), for all six common DAP metabolites (i.e., dimethylphosphate, dimethylthiophosphate, dimethyldithiophosphate, diethylphosphate, diethylthiophosphate, and diethyldithiophosphate). Each method showed a relative recovery range of 94-119% (for GC-FPD) and 92-103% (for GC-MS), and relative standard deviations (RSD) of less than 20%. Cross-validation was performed on the same set of urine samples (n=46) collected from pregnant women residing in the agricultural areas of northern Thailand. The results from split sample analysis from both laboratories agreed well for each metabolite, suggesting that each method can produce comparable data. In addition, results from analyses of specimens from the German External Quality Assessment Scheme (G-EQUAS) suggested that the GC-FPD method produced accurate results that can be reasonably compared to other studies. PMID:24280209

Prapamontol, Tippawan; Sutan, Kunrunya; Laoyang, Sompong; Hongsibsong, Surat; Lee, Grace; Yano, Yukiko; Hunter, Ronald Elton; Ryan, P Barry; Barr, Dana Boyd; Panuwet, Parinya

2014-01-01

107

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

108

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

109

[Survey of pesticide residues in imported fruit products (1994.4-2006.3)].  

Science.gov (United States)

A survey of pesticide residues in 600 imported fruit products on the Tokyo market from April 1994 to March 2006 was carried out. Thirty kinds of pesticides, including organophosphorus, organochlorine, carbamate, and pyrethroid, were detected between levels of Tr (below 0.01 ppm) to 0.37 ppm from 75 samples. Residual pesticides were detected from fruit products, dried fruits and pressed juice. A high frequency of pesticide residues was observed in peels, whole body of fruits and products which contained them. Residue levels of these pesticides were calculated as between less than 0.1 and 3.9% of their ADI values according to the daily intake of fruit products. Therefore, these fruit products should be safe when eaten in customary amounts. PMID:19897954

Kobayash, Maki; Ohtsuka, Kenji; Tamura, Yasuhiro; Tomizawa, Sanae; Sakai, Naoko; Kamijo, Kyoko; Kageyama, Yuriko; Takano, Ichiro; Nagayama, Toshihiro

2009-10-01

110

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

111

Use of spermine and thiabendazole as analyte protectants to improve direct analysis of 16 carbamates by gas chromatography-mass spectrometry in green vegetable matrices.  

Science.gov (United States)

The carbamates are a well-known thermosensible pesticides class, which are highly prone to degradation via fragmentation and/or rearrangement mechanisms leading to a difficult direct gas chromatography (GC) analysis, i.e., without derivatization. In this paper, spermine and thiabendazole both at 1 mg/mL were highlighted as efficient analyte protectants to improve the direct and simultaneous analysis of 16 carbamates both in solvent and green vegetable matrices. These two molecules were compared in mixture or in combination with three well-known efficient analyte protectants 3-ethoxy-1,2-propanediol, D-sorbitol, and L-gulonic acid-gamma-lactone. The potential benefits were investigated in GC hyphenated to mass spectrometry (GC-MS) with two injection modes: programmable temperature vaporizing injector in a solvent split mode (PTV-SSI) and on-column injection (OCI). It was shown that the combined effect of the five protective agents led to the best sensitivity improvement with limits of detection between 0.1-0.4 and 0.03-0.1 microg/kg and limits of quantification between 0.3-1.1 and 0.1-0.5 microg/kg for PTV-SSI and OCI mode, respectively. The correlation coefficients from the analyzed 1-500 microg/kg range were all >0.999 both in the solvent and matrices studied. The recoveries of carbamates from three spiked matrices over five replicates at 20 and 100 microg/kg were in the range 90-107% with relative standard deviation (RSD) equal to 2-7% for PTV-SSI and 92-107% with an RSD equal to 1-6% for OCI. The use of spermine and thiabendazole with other analyte protectants shows very efficient partial or total reduction of breakdown of the most sensitive carbamates such as the N-sulfenylated ones. PMID:19415245

Przybylski, Cédric; Bonnet, Véronique

2009-06-01

112

Pesticide Safety Tips  

Science.gov (United States)

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

113

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 ...

114

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

115

Pesticides residues in the Prochilodus costatus (Valenciennes, 1850) fish caught in the São Francisco River, Brazil.  

Science.gov (United States)

The objective of this study was to determine the levels of pesticides in the fish Prochilodus costatus caught in São Francisco River, one of most important rivers in Brazil. Thirty-six fish were captured in three different areas, and samples of the dorsal muscle and pooled viscera were collected for toxicological analysis. We evaluated the presence of 150 different classes of insecticides, fungicides, herbicides and acaricides by multiresidue analysis technique using liquid chromatography-tandem mass spectrometry (LC-MS/MS), with the limit of detection of 5 ppb. In this study, organophosphorus and carbamate pesticides were detected at the highest levels in the caught fish. Among the 41 organophosphorus pesticides surveyed, nine types were detected (chlorpyrifos, diazinon, dichlorvos, disulfoton, ethion, etrimfos, phosalone, phosmet and pyrazophos) in the muscle, viscera pool, or both in 22 (61.1%) fish. Sampled tissues of 20 (55.6%) fish exhibited at least one of the eight evaluated carbamate pesticides and their metabolites: aldicarb, aldicarb sulfoxide, carbaryl, carbofuran, carbosulfan, furathiocarb, methomyl and propoxur. Fungicides (carbendazim, benalaxyl, kresoxim-methyl, trifloxystrobin, pyraclostrobin and its metabolite BF 500 pyraclostrobin), herbicides (pyridate and fluasifop p-butyl), acaricide (propargite) and pyrethroid (flumethrin) were also detected. In conclusion, P. costatus fish caught in the São Francisco River contained residues of 17 different pesticides, in both muscles and the viscera pool, indicating heavy environmental contamination by pesticides in the study area. PMID:25844860

Oliveira, Fabiano A; Reis, Lilian P G; Soto-Blanco, Benito; Melo, Marília M

2015-06-01

116

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  

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Full Text Available 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.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:petroleum 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

2010-05-01

117

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

118

Pesticide personal protective clothing.  

Science.gov (United States)

A fairly large established data base provides information on clothing worn by U.S. and Canadian farmers to work with pesticides, their attitudes and beliefs about pesticide risk, and clothing as a dermal barrier. Very limited similar data are available for farmers in less developed countries. Clearly, farmers perceive the benefits of pesticides to far exceed any risks. While few report poisoning symptoms, most believe that their usual work clothing offers a sufficient pesticide barrier, and few wear special-purpose protective clothing. Gloves of various materials, including cotton and leather, appear to be the major protective clothing item. Although farmers feel that their usual work clothing provides excellent protection, fabric penetration research does not support this. Shirting-weight fabrics offer some limited protection against light spray of field-strenght pesticides. Heavier-weight fabrics, such as denim and twill, are better barriers. With a heavier spray or a spill, usual work clothing does not give sufficient protection. Greater protection can usually be achieved with the use of a fluorocarbon finished fabric, such as Scotchgard or Zepel. Scotchgard can readily be applied at home. A durable-press finish does not appear to improve fabric's pesticide-barrier resistance and some data suggest that it may decrease barrier properties. A second alternative for increased protection is the use of a special-purpose fabric, such as a coated nonwoven or possibly Gore-Tex. Numerous other new "waterproof breathable" fabrics have recently come to the market. Many of these are finished or coated fabrics and one would expect them to be at least somewhat resistant to pesticides. However, they have not been tested. Wearing an additional layer also appears to be another clothing strategy to minimize exposure. Fabric penetration research also shows that pesticide formulation, volume or spray regime, concentration, and active ingredients influence the barrier properties of fabrics. Clothing evaluation studies have shown that protective clothing and coveralls of various materials and designs were effective in reducing exposure. Results of some of these studies suggested that the farmer's typical work clothing was more effective than fabric penetration results suggested. This apparent conflict is not surprising, given the methods used in both types of research. The field studies use pads placed in various areas under the clothing. This method assumes that exposure is uniform over entire body regions. But fluorescent tracer research has shown that this is not a valid assumption (DeJonge et al. 1985; Fenske 1988). Also, the way in which the pads are attached may make a difference, although no research has examined this issue.(ABSTRACT TRUNCATED AT 400 WORDS) PMID:1771275

Branson, D H; Sweeney, M

1991-01-01

119

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

120

Isosorbide-2-carbamate esters: potent and selective butyrylcholinesterase inhibitors.  

Science.gov (United States)

In this study, we report the SAR and characterization of two groups of isosorbide-based cholinesterase inhibitors. The first was based directly on the clinically used nitrate isosorbide mononitrate (ISMN) retention of the 5-nitrate group and introduction of a series of 2-carbamate functionalities. The compounds proved to be potent and selective inhibitors of human plasma butyrylcholinesterase ( huBuChE). In the second group, the nitrate ester was removed and replaced with a variety of alkyl and aryl esters. These generally exhibited nanomolar potency with high selectivity for BuChE over acetylcholinesterase (AChE). The most potent and selective compound was isosorbide-2-benzyl carbamate-5-benzoate with an IC 50 of 4.3 nM for BuChE and >50000 fold selectivity over human erythrocyte AChE. Inhibition with these compounds is time-dependent, competitive, and slowly reversible, indicating active site carbamylation. PMID:18817366

Carolan, Ciaran G; Dillon, Gerald P; Gaynor, Joanne M; Reidy, Sean; Ryder, Sheila A; Khan, Denise; Marquez, Juan F; Gilmer, John F

2008-10-23

121

Phenyl N-(2-methyl­phen­yl)carbamate  

Science.gov (United States)

In the title compound, C14H13NO2, the aromatic rings attached to the O and N atoms make dihedral angles of 62.65?(9) and 38.28?(11)°, respectively, with the central carbamate group. The benzene rings are oriented at a dihedral angle of 39.22?(10)°. In the crystal, a very weak C—H?? inter­action occurs. PMID:21582896

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

2009-01-01

122

Design, Synthesis, and Preliminary Evaluation of Doxazolidine Carbamates as Prodrugs Activated by Carboxylesterases  

OpenAIRE

The synthesis and tumor cell growth inhibition by Doxazolidine carbamate prodrugs are reported. The carbamates were designed for selective hydrolysis by one or more human carboxylesterases to release Doxazolidine (Doxaz), the formaldehyde-oxazolidine of doxorubicin that cross-links DNA to trigger cell death. Simple butyl and pentyl, but not ethyl, carbamate prodrugs inhibited the growth of cancer cells that overexpress carboxylesterase CES1 (hCE1) and CES2 (hiCE). Relative CES1 and CES2 expre...

Burkhart, David J.; Barthel, Benjamin L.; Post, Glen C.; Kalet, Brian T.; Nafie, Jordan W.; Shoemaker, Richard K.; Koch, Tad H.

2006-01-01

123

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

OpenAIRE

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 ...

Tilborg, Anae?lle; Lanners, Steve; Norberg, Bernadette; Wouters, Johan

2013-01-01

124

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

International Nuclear Information System (INIS)

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

125

Oxidative Stress Induced by Different Pesticides in the Land Snails, Helix aspersa  

OpenAIRE

The present study was designated to compare the ability of the two carbamate compounds methomyl and carbofuran, the organophosphorus compound chlorpyrifos and the bipyridylium compound paraquat to induce the oxidative stress and affect some biochemical targets in the terrestrial snail, Helix aspersa. LD50 values for these pesticides were determined 48 h following topical application. They were 240, 500, 900 and 920 ?g/snail for methomyl, carbofuran, chlorpyrifos and paraquat, respectively. S...

Salama, Ahmed K.; Osman, Khaled A.; Saber, Nabila A.; Soliman, Salah A.

2005-01-01

126

The Enhanced Carbamate Adsorption of Modified Bentonite with Coscinium  

OpenAIRE

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

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

2013-01-01

127

A case of methanol intoxication caused by methomyl pesticide ingestion.  

Science.gov (United States)

When clinicians treat patients with pesticide poisoning, they often pay attention only to the chief toxic agent and ignore the toxicity of the pesticide's additives or solvents. Occasionally, however, a solvent (e.g. methanol) may itself be the cause of poisoning. We report a case of acute methanol intoxication that occurred after ingestion of a methomyl pesticide that contained methanol as an additive. A 49-year-old man was brought to the emergency department in an unconscious state after ingestion of 20 ml of a carbamate pesticide (chief ingredient: methomyl; active ingredient: methanol). Upon arrival, he was semicomatose and did not breathe spontaneously; however, his cholinesterase level was within normal limits and cholinergic symptoms were not observed. High anion gap metabolic acidosis was present. His blood ethanol level was 74.8 mg/dL. The urine methanol level was 55.60 mg/dL, and urine ethanol level was 22.0 mg/dL. He was treated with hemodialysis; subsequently, his metabolic acidosis resolved and he returned to normal mental status. We guessed that methanol, as the solvent of the methomyl, had produced the symptoms. When treating pesticide-poisoned patients, clinicians should identify the solvent used in the pesticide, because solvents such as methanol may exacerbate the symptoms of poisoned patients. PMID:23023026

Gil, H W; Hong, J R; Song, H Y; Hong, S Y

2012-12-01

128

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

Science.gov (United States)

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

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

2004-08-01

129

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

OpenAIRE

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-secondar...

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

2010-01-01

130

Detection and quantification of dithiocarbamate pesticides by Surface Enhanced Raman Spectroscopy (SERS)  

Science.gov (United States)

Dithiocarbamates are a subclass of carbamate pesticides that are widely used as insecticidal agents on food crops in the US and abroad. Quantitative determination of trace quantities of dithiocarbamates is necessary in order to mitigate potential human exposure via pesticide residues left on inadequately washed food items as well as groundwater contamination from agricultural runoff. The focus of this research is on the development and optimization of a Surface Enhanced Raman Spectroscopy (SERS) based analytical technique for the quantitative determination of trace amounts of dithiocarbamate pesticides in different matrices. Gold nanoparticles of different shapes and sizes will be investigated to determine the suitability of these materials as SERS active substrates for the trace analysis of dithiocarbamate pesticides. Analytical sensitivity will be evaluated by determining the limits of detection using established statistical methods.

Saute, Benjamin Calvin

131

[Survey of pesticide residues in imported spices and herbs (1997.4-2011.3)].  

Science.gov (United States)

A survey of pesticide residues in 313 samples of imported spices and herbs on the Tokyo market from April 1997 to March 2011 was carried out. Thirty-seven kinds of pesticides, including organophosphorus, organochlorine, pyrethroid, carbamate and others, were detected between levels of trace (below 0.01 ppm) and 3.3 ppm from 64 samples. The rate of detection was highest in peel (100%) followed by stem (66.7%), fruit (34.5%), bark (33.3%), flower (31.3%) and leaf (14.7%). No residues were detected in root, seed or whole grass. Organochlorine pesticides were detected in all plant parts. The insecticides were detected in products from all production areas, suggesting that their use is common. Residue levels of these pesticides were calculated as less than 1% of their ADI values, based on the daily intake of spices and herbs. Therefore, these spices and herbs should be safe when consumed in customary amounts. PMID:24025211

Kobayashi, Maki; Ohtsuka, Kenji; Tamura, Yasuhiro; Tomizawa, Sanae; Kinoshita, Teruaki; Kamijo, Kyoko; Iwakoshi, Keiko; Sato, Chizuko; Nagayama, Toshihiro; Takano, Ichiro

2013-01-01

132

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

Science.gov (United States)

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

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

2011-01-01

133

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

Science.gov (United States)

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

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

2014-06-27

134

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

Scientific Electronic Library Online (English)

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

David, Dallos Corredor; Jairo Arturo, Guerrero Dallos.

2005-12-05

135

Evaluation of carbamate insecticides as chemotherapeutic agents for cancer  

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

Mohd. Amanullah

2011-01-01

136

Effect of methomyl formulation, a carbamate pesticide on ovarian follicular development and fertility in albino mice.  

Science.gov (United States)

Administration of 5 mg methomyl (40%) kg(-1) b.wt. mouse(-1) (equal to 50% of LD50 dose), every day for 90 days to adult female mice resulted in a significant decrease in body weight, relative weight of the ovary, uterus and fallopian tube; mean number of small, preantral, antral and pre-ovulatory follicles and fertility compared to controls. On the other hand, total duration of the estrous cycle was significantly increased compared to controls. One month after the cessation of the treatment (a commercial methomyl preparation-lannate) the effect on estrous cycle and organ weight was not restored. Treatment of 2.5 mg or 1 mg lannate kg(-1) b. wt., although did not alter duration of the estrous cycle; relative weight of the ovary, uterus, and fallopian tube and fertility, caused a significant decrease in mean number of small follicles compared to controls. All the groups of mice treated with lannate showed loss in body weight (15.15% in 1 mg, 6.61% in 2 mg and 12.16% in 5 mg treated groups) whereas controls showed a gain in body weight (20.02%) during the period of experimentation. The results indicate that 5 mg lannate kg(-1) b. wt causes loss of follicles and infertility, whereas lower dosages (2.5 and 1 mg) reduce the number of small follicles which might shorten reproductive life span of mice. PMID:23033640

Shanthalatha, A; Madhuranath, B N; Yajurvedi, H N

2012-01-01

137

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

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

Maria Isabel Ribeiro Alves

2010-10-01

138

Pesticides (Environmental Health Student Portal)  

Science.gov (United States)

... pesticides, and the balance between the risks and benefits of using pesticides. Chemicals: Messing Around in Nature's ... dictionaries, and various organizations concerning pesticides. Pesticides and Food: Health Problems Pesticides May Pose (U.S. Environmental Protection ...

139

National Pesticide Information Center  

Science.gov (United States)

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

140

What Is a Pesticide?  

Science.gov (United States)

... killers. Some swimming pool chemicals. What is the balance between the risks and benefits of pesticides? By ... substances are not regulated as pesticides? The U.S. definition of pesticides is quite broad, but it does ...

141

Safe Storage of Pesticides  

Science.gov (United States)

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 ...

142

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

Science.gov (United States)

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

143

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

Scientific Electronic Library Online (English)

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

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

2006-10-01

144

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

145

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

146

Comparative effect of pesticides on brain acetylcholinesterase in tropical fish.  

Science.gov (United States)

Monitoring of pesticides based on acetylcholinesterase (AChE; EC 3.1.1.7) inhibition in vitro avoids interference of detoxification defenses and bioactivation of some of those compounds in non-target tissues. Moreover, environmental temperature, age and stress are able to affect specific enzyme activities when performing in vivo studies. Few comparative studies have investigated the inter-specific differences in AChE activity in fish. Screening studies allow choosing the suitable species as source of AChE to detect pesticides in a given situation. Brain AChE from the tropical fish: pirarucu (Arapaima gigas), cobia (Rachycentron canadum) and Nile tilapia (Oreochromis niloticus) were characterized and their activities were assayed in the presence of pesticides (the organophosphates: dichlorvos, diazinon, chlorpyrifos, temephos, tetraethyl pyrophosphate- TEPP and the carbamates: carbaryl and carbofuran). Inhibition parameters (IC?? and Ki) for each species were found and compared with commercial AChE from electric eel (Electrophorus electricus). Optimal pH and temperature were found to be 8.0 and 35-45 °C, respectively. A. gigas AChE retained 81% of the activity after incubation at 50 °C for 30 min. The electric eel enzyme was more sensitive to the compounds (mainly carbofuran, IC?? of 5 nM), excepting the one from A. gigas (IC?? of 9 nM) under TEPP inhibition. These results show comparable sensitivity between purified and non-purified enzymes suggesting them as biomarkers for organophosphorus and carbamate detection in routine environmental and food monitoring programs for pesticides. PMID:23137979

Assis, Caio Rodrigo Dias; Linhares, Amanda Guedes; Oliveira, Vagne Melo; França, Renata Cristina Penha; Carvalho, Elba Veronica Matoso Maciel; Bezerra, Ranilson Souza; de Carvalho, Luiz Bezerra

2012-12-15

147

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

OpenAIRE

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 ...

Jean-Claude Assad; Olurominiyi Ibitayo; Lidell, Frances P.; Sayed El-Sheikh; El-Adarosy Goma; Romeh, Ahmed A.; Ragheb, Didair A.; Curtina Moreland-Young; Ashour, Bassem A.; Tchounwou, Paul B.

2002-01-01

148

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

149

Pesticide poisoning.  

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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

150

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2009-01-15

151

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

Science.gov (United States)

A triple quadrupole GC-QqQ-MS/MS method was optimized for multiresidue analysis of over 180 pesticides in blackcurrants. The samples were prepared by using a modified quick, easy, cheap, effective, rugged and safe (QuEChERS) analytical protocol. To reduce matrix co-extractives in the final extract, the supernatant was cleaned up by dispersive-solid phase extraction (dispersive-SPE) with a mixture of sorbents: primary secondary amine (PSA), octadecyl (C18) and graphitized carbon black (GCB). The validation results demonstrated fitness for purpose of the streamlined method. The overall recoveries at the three spiking levels of 0.01, 0.05 and 0.2 mg kg(-1) spanned between 70% and 116% (102% on average) with relative standard deviation (RSD) values between 3% and 19% except for chlorothalonil (23%). Response linearity was studied in the range between 0.005 and 0.5 mg kg(-1). The matrix effect for each individual compound was evaluated through the study of ratios of the slopes obtained in solvent and blackcurrant matrix. The optimized method provided small matrix effect (matrix effect was 10-20%, 20-30% and >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

152

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

International Nuclear Information System (INIS)

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

153

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

154

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

Science.gov (United States)

...removing carbamates from the Universal Treatment standards? Underlying...Section 268.48, Table UTS--Universal Treatment Standards, except...that Significantly Affect Energy Supply, Distribution, or...48, the Table of UTS--Universal Treatment Standards is...

2011-06-13

155

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

156

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

157

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

158

Pesticide transport simulation in a tropical catchment by SWAT  

International Nuclear Information System (INIS)

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. - Highlights: • We performed a global LH-sensitivity analysis of all pesticide related parameters. • Key physical parameters are associated to percolation, degradation and sorption. • We simulated the measured loads of three different pesticides. • We performed an uncertainty analysis of all pesticide simulations. • All Pesticides differed considerably in their sensitivity and simulation behavior. - Pesticide load simulations of three pesticides were modeled by SWAT, providing clues on how to handle pesticides in future SWAT studies

159

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

160

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

Science.gov (United States)

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

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

2014-01-31

161

Leaching and degradation of pesticides in groundwater layers  

International Nuclear Information System (INIS)

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

162

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

163

Groundbreaking Pesticide Ban  

Science.gov (United States)

Learn how one child's willingness to share her experience of life-threatening exposure to lawn pesticides helped inspire a citywide ban of pesticides for lawn or garden use, in this video segment adapted from Playing with Poison.

WGBH Educational Foundation

2011-07-01

164

Pesticides and Pregnancy  

Science.gov (United States)

... What if I am exposed to pesticides while breastfeeding? Pesticides may be found in breast milk, but ... CJ et al. 2013. Effects of metformin-diet intervention before and throughout pregnancy on obstetric and neonatal ...

165

Pesticide Fact Sheets  

Science.gov (United States)

... Page —> NPIC Publications —> Pesticide Fact Sheets Pesticide Fact Sheets NPIC fact sheets are designed to answer questions ... will need Adobe Reader . What Type of Fact Sheets Does NPIC Produce? Active Ingredient Fact Sheets Active ...

166

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.

167

Introduction to Pesticide Drift  

Science.gov (United States)

... Drift Share Facebook Twitter Google+ Pinterest Contact Us Introduction to Pesticide Drift Pesticide spray drift is the ... and Toxics Sustainable Practices Water Laws & Regulations By Business Sector By Topic Compliance Enforcement Laws and Executive ...

168

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)

169

Reliability of the TTC approach: learning from inclusion of pesticide active substances in the supporting database.  

Science.gov (United States)

Data on pesticide active substances were used to assess the reliability of the Threshold of Toxicological Concern (TTC) approach. Pesticides were chosen as a robust test because of their potential for toxicity. 328 pesticide substances were classified on the basis of their chemical structure, according to the generic scheme proposed by the European Food Safety Authority. 43 carbamates and organophosphates were allocated to the group for neurotoxicity alerts, and 279 substances to Cramer structural Class III. For Class III, the 5th percentile value as calculated from the cumulative distribution curve of the no-observed-effect levels (0.20?mg/kg bw per day), was slightly higher than that determined by Munro (0.15?mg/kg bw per day) from his original database. The difference is explained by the inclusion of carbamates and organophosphates in Munro's Class III. Consideration of the acceptable daily intakes and their underlying toxicity data showed that the TTC approach is conservative for 96.2% of the substances. Overall, this analysis gives added support to the utility of the generic scheme of application of the TTC approach for hazard assessment of substances for which few or no experimental toxicity data are available. A convenient alternative to the Cramer decision tree is proposed. PMID:25455897

Feigenbaum, Alexandre; Pinalli, Roberta; Giannetto, Marco; Barlow, Susan

2015-01-01

170

Anti-cancer activity of carbamate derivatives of melampomagnolide B.  

Science.gov (United States)

Melampomagnolide B (MMB) is a natural sesquiterpene structurally related to parthenolide (PTL). We have shown that MMB exhibits anti-leukemic properties similar to PTL. Unlike PTL, the presence of a primary hydroxyl group in the MMB molecule allows the opportunity for examining the biological activity of a variety of conjugated analogs of MMB. We have now synthesized a series of carbamate analogs of MMB and evaluated these derivatives for anti-cancer activity against a panel of sixty human cancer cell lines. Analogs 6a and 6e exhibited promising anti-leukemic activity against human leukemia cell line CCRF-CEM with GI50 values of 680 and 620 nM, respectively. Analog 6a also showed GI50 values of 1.98 and 1.38 ?M respectively, against RPMI-8226 and SR leukemia cell lines and GI50 values of 460 and 570 nM against MDA-MB-435 melanoma and MDA-MB-468 breast cancer cell lines, respectively. Analog 6e had GI50 values of 650 and 900 nM against HOP-92 non-small cell lung and RXF 393 renal cancer cell lines. PMID:24928404

Janganati, Venumadhav; Penthala, Narsimha Reddy; Madadi, Nikhil Reddy; Chen, Zheng; Crooks, Peter A

2014-08-01

171

Carbamate insecticide methomyl confers cytotoxicity through DNA damage induction.  

Science.gov (United States)

Carbamate insecticide methomyl could induce genotoxic effects, including micronuclei, chromosome aberrations and sister-chromatid exchanges. However, methomyl induction of cytotoxicity through DNA damage is largely unknown. Here we identify cytotoxicity and potential genotoxicity of methomyl in vitro. We have employed alkaline comet assay, ?H2AX foci formation and DNA ladder assay to detected DNA damage and apoptosis of Drosophila S2, HeLa and HEK293 cells. The alkaline comet assay was used to evaluate total DNA single strand breaks (SSBs) in the target cells exposed in vitro to sublethal concentrations of methomyl. As expected, methomyl induced significant concentration-dependent increases in DNA damage of target cells compared with the negative control, as measured by increases in tail length (?m), tail DNA (percentage of the comet tail) and tail moment (arbitrary units). In agreement with the comet assay data, the percentage of ?H2AX positive reaction in HeLa cells also revealed methomyl caused DNA double strand breaks (DSBs) in a time-dependent manner. Moreover, methomyl induced a significant increase of apoptosis in Drosophila S2, HeLa and HEK293 cells in a concentration- and time-dependent manner, as determined by Urea PAGE DNA fragmentation analysis. In conclusion, methomyl is a strongly genotoxic agent that induces cell DNA damage and apoptosis in vitro at these sublethal concentrations. PMID:23266502

Guanggang, Xiang; Diqiu, Li; Jianzhong, Yuan; Jingmin, Guan; Huifeng, Zhai; Mingan, Shi; Liming, Tao

2013-03-01

172

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

173

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

174

Pesticide National Synthesis Project  

Science.gov (United States)

The Pesticide National Synthesis Project homepage offers a number of publications and reports on pesticides in the Hydrologic System. The site also features data sets, national maps of pesticide use, and some special topic reports, as well as information on the Project and its staff.

175

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.

176

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

177

77 FR 15012 - Receipt of Several Pesticide Petitions Filed for Residues of Pesticide Chemicals in or on Various...  

Science.gov (United States)

...validated. The method involves solvent extraction followed by liquid- liquid partitioning...0.01 ppm. Aqueous organic solvent extraction, column clean up, and quantitation...the biochemical pesticide polyoxin D zinc salt when used as a fungicide for...

2012-03-14

178

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

Directory of Open Access Journals (Sweden)

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

Karl Schosinsky

2009-03-01

179

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

180

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

181

Quality Control Of Selected Pesticides With GC  

International Nuclear Information System (INIS)

The practical quality control of selected pesticides with GC is treated. Detailed descriptions are given on materials and methods used, including sample preparation and GC operating conditions. The systematic validation of multi methods is described, comprising performance characteristics in routine analysis, like selectivity, specificity etc. This is illustrated by chromatograms, calibration curves and tables derived from real laboratory data. (author)

182

Assessment of acute oral and dermal toxicity of 2 ethyl-carbamates with activity against Rhipicephalus microplus in rats.  

Science.gov (United States)

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

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

2014-01-01

183

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

Science.gov (United States)

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

184

Ethyl carbamate levels in wine and spirits from markets in Hebei Province, China.  

Science.gov (United States)

Ethyl carbamate (EC) in wine, grain spirits and wine sauce (145 samples) was analysed using solid-phase extraction and stable isotope dilution GC/MS. Samples were obtained from markets in eight areas (Shijiazhuang, Baoding, Handan, Qinhuangdao, Langfang, Zhangjiakou, Xingtai and Cangzhou) of Hebei Province, China. The method had a limit of detection of 2 µg kg?¹, with recoveries varying from 95.7 to 102% and RSD ranging 2.3-5.6%. The average concentrations of ethyl carbamate in wines, grain spirits and wine sauce were 14.7 (<2.0-44.5) µg kg?¹, 33.8 (2.9-129) µg kg?¹ and 8.7 (<2.0-63.3) µg kg?¹, respectively. The results led to the development of limit standards that can be used to predict the concentration of ethyl carbamate in Chinese fermented wines. PMID:24779655

Liu, Y P; Dong, B; Qin, Z S; Yang, N J; Lu, Y; Yang, L X; Chang, F Q; Wu, Y N

2011-01-01

185

Carbamate stabilities of sterically hindered amines from quantum chemical methods: relevance for CO2 capture.  

Science.gov (United States)

The influence of electronic and steric effects on the stabilities of carbamates formed from the reaction of CO2 with a wide range of alkanolamines was investigated by quantum chemical methods. For the calculations, B3LYP, M11-L, MP2, and spin-component-scaled MP2 (SCS-MP2) methods were used, coupled with SMD and SM8 solvation models. A reduction in carbamate stability leads to an increased CO2 absorption capacity of the amine and a reduction of the energy required for solvent regeneration. Important factors for the reduction of the carbamate stability were an increase in steric hindrance around the nitrogen atom, charge on the N atom and intramolecular hydrogen bond strength. The present study indicates that secondary ethanolamines with sterically hindering groups near the N atom show significant potential as candidates for industrial CO2-capture solvents. PMID:24203852

Gangarapu, Satesh; Marcelis, Antonius T M; Zuilhof, Han

2013-12-01

186

Inhibition of cholinesterase activity by soil extracts and predicted environmental concentrations (PEC) to select relevant pesticides in polluted soils.  

Science.gov (United States)

The correlation of predicted environmental concentrations (PEC) with cholinesterase activity inhibition detected in soil extracts was determined. PEC was derived from organophosphate (OP) and carbamate (CA) compounds applied to a flower crop area. Samples of surface soil (0 - 30 cm in depth) and subsurface soil (30 to 60 cm in depth) were taken from a flower crop area in which OP pesticides such as acephate ((RS)-N-[methoxy(methylthio)phosphinoyl]acetamide), dimethoate (2-dimethoxyphosphinothioylthio-N-methylacetamide) and methyl parathion (O,O-dimethyl O-4-nitrophenyl phosphorothioate), and CA pesticides such as carbendazim (methyl benzimidazol-2-ylcarbamate), carbofuran (2,3-dihydro-2,2-dimethylbenzofuran-7-yl methylcarbamate) and methomyl (S-methyl (EZ)-N-(methylcarbamoyloxy) thioacetimidate) were applied for two years. Weekly loads of these pesticides were registered to estimate the annual load of each compound. Physicochemical analysis and relative inhibition of cholinesterasic activity were measured for each soil sample. PEC values were estimated with Pesticide Analytical Model (PESTAN), a leach model, for each pesticide using soil sample data obtained from physicochemical analysis. From all pesticides tested, only acephate and methomyl showed a significant correlation (p < 0.01) between PEC values and inhibition cholinesterase activity of soil extracts. These results suggest that inhibition of cholinesterase activity observed in soil extracts is produced mainly by these two pesticides. Further studies could be developed to measure acephate and methomyl concentrations to reduce their environmental impact. PMID:20390953

Meza, Juan C Sanchez; Perez, Pedro Avila; Salin, Manuel Borja; Salazar, Victor F Pacheco; Lapoint, Tom

2010-04-01

187

Validation of one-step cleanup and separation method of polychlorinated biphenyls, organochlorine pesticides, and polycyclic aromatic hydrocarbons from atmospheric gas- and particle-phase samples.  

Science.gov (United States)

A one-step cleanup method is described for the determination of PAHs, PCBs and OCPs in air (gas and particulate phase) samples. Analytes were extracted from ambient air samples using soxhlet extraction with a solvent mixture of dichloromethane and petroleum ether (1:4) for 24h. They were concentrated, separated and fractionated on a florisil and alumina column. The amounts of florisil (1g or 2g) with/without alumina were tested in the cleanup column. The study systematically investigated the effects of solvent types, and the amounts of florisil and alumina, on the performance of the cleanup process. The first fraction was eluted with 25 mL hexane, and analyzed for PCBs. The second fraction was collected via 40 mL hexane-ethyl acetate (1:1) solvent mixture, and analyzed for OCPs and PAHs. The optimized method yielded average recoveries between 88% and 99% for PCBs; 56% and 118% for PAHs; and 51% and 128% for OCPs. Other validation parameters were also investigated, such as MDL, LOQ, linear range, sensitivity (r(2)). An oven-program optimization and adjustment of GC-MS were performed. For internal quality control, surrogate recoveries and field blanks values were calculated. External calibration curves were prepared for PAHs, and internal calibration curves were preferred for OCP and PCBs. PMID:24054572

Yenisoy-Karaka?, Serpil; Gaga, Eftade O

2013-10-15

188

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

189

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

190

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

Science.gov (United States)

We report on the development and validation under ISO 17025 criteria of a multi-residue confirmatory method to identify and quantify 17 widely chemically different pesticides (insecticides: Carbofuran, Methiocarb, Pirimicarb, Dimethoate, Fipronil, Imidacloprid; herbicides: Amidosulfuron, Rimsulfuron, Atrazine, Simazine, Chloroturon, Linuron, Isoxaflutole, Metosulam; fungicides: Diethofencarb) and 2 metabolites (Methiocarb sulfoxide and 2-Hydroxytertbutylazine) in honey. This method is based on an on-column liquid-liquid extraction (OCLLE) using diatomaceous earth as inert solid support and liquid chromatography (LC) coupled to mass spectrometry (MS) operating in tandem mode (MS/MS). Method specificity is ensured by checking retention time and theoretical ratio between two transitions from a single precursor ion. Linearity is demonstrated all along the range of concentration that was investigated, from 0.1 to 20 ng g(-1) raw honey, with correlation coefficients ranging from 0.921 to 0.999, depending on chemicals. Recovery rates obtained on home-made quality control samples are between 71 and 90%, well above the range defined by the EC/657/2002 document, but in the range we had fixed to ensure proper quantification, as levels found in real samples could not be corrected for recovery rates. Reproducibility is found to be between 8 and 27%. Calculated CCalpha and CCbeta (0.0002-0.943 ng g(-1) for CCalpha, and 0.0002-1.232 ng g(-1) for CCbeta) show the good sensitivity attained by this multi-residue analytical method. The robustness of the method has been tested in analyzing more than 100 raw honey samples collected from different areas in Belgium, as well as some wax and bee samples, with a slightly adapted procedure. PMID:17416380

Pirard, C; Widart, J; Nguyen, B K; Deleuze, C; Heudt, L; Haubruge, E; De Pauw, E; Focant, J-F

2007-06-01

191

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 [...] 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.

192

POEM: PESTICIDE ORCHARD ECOSYSTEM MODEL  

Science.gov (United States)

The Pesticide Orchard Ecosystem Model (POEM) is a mathematical model of organophosphate pesticide movement in an apple orchard ecosystem. In addition submodels on invertebrate population dynamics are included. The fate model allows the user to select the pesticide, its applicatio...

193

Comparison of solid phase- and liquid/liquid-extraction for the purification of hair extract prior to multi-class pesticides analysis.  

Science.gov (United States)

The present study focuses on the influence of a purification step - after extraction of pesticides from hair and before analysis of the extract - on the sensitivity of analytical methods including compounds from different chemical classes (both parent and metabolites). Sixty-seven pesticides and metabolites from different chemical classes were tested here: organochlorines, organophosphates, carbamates, pyrethroids, ureas, azoles, phenylpyrazoles and neonicotinoids. Two gas chromatography-negative chemical ionization-tandem mass spectrometry methods and one based on ultra-performance liquid chromatography-electrospray tandem mass spectrometry were used. Seven solid-phase extraction cartridges: C18, S-DVB, PS-DVB, GCB, GCB/PSA, SAX/PSA and Florisil/PSA were tested and compared to more classical liquid-liquid extraction procedures using ethyl acetate, hexane and dichloromethane. Although LLE allowed obtaining good results for some compounds, on the whole, SPE clearly provided better recovery for the majority of the pesticide residues tested in the present study. GCB/PSA was clearly the best suited to non-polar compounds such as organochlorines, pyrethroids and organophosphates, with recovery ranging from 45.9% (diflufenican) to 117.1% (parathion methyl). For hydrophilic metabolites (e.g. dialkyl phosphates and other organophosphate metabolites, pyrethroid metabolites, phenols and carbamate metabolites), the best results were obtained with PS-DVB, with recovery ranged from 10.3% (malathion monocarboxylic acid) to 93.1% (para-nitrophenol). For hydrophilic parent pesticides (e.g. neonicotinoids, carbamates, azoles) and metabolites without nucleophilic functions, the best recovery was obtained with SAX/PSA, with recovery ranging from 52.1% (3-hydroxycarbofuran) to 100.9% (3,4-dichloroaniline). Solid phase extraction was found to be more suitable than the liquid-liquid extraction for pesticides and their metabolites determination in terms of number of extracted compounds and their recovery. Moreover, the use of solid phase extraction cartridges has enabled the reduction of the analytical background noise, resulting in better chromatographic separations. PMID:24631817

Duca, Radu-Corneliu; Salquebre, Guillaume; Hardy, Emilie; Appenzeller, Brice M R

2014-04-01

194

Ban of Neonicotinoid Pesticides  

OpenAIRE

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

Inthasen, Prapaporn

2014-01-01

195

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

196

Dietary exposure of Hong Kong adults to pesticide residues: results of the first Hong Kong Total Diet Study.  

Science.gov (United States)

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 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

197

Optical Biosensor with Multienzyme System Immobilized onto Hybrid Membrane for Pesticides Determination  

Directory of Open Access Journals (Sweden)

Full Text Available A construction of optical biosensor based on simultaneous immobilization of acetylcholinesterase and choline oxidase enzymes for the detection of pesticides residues is described. Different kinds of novel SiO2 hybrid membranes were synthesized to be suitable for optical biosensors using sol-gel techniques. The bioactive component of the sensor consists of a multi-enzyme system including acetylcholinesterase and choline oxidase covalently immobilized on new hybrid membranes. The sensor exhibited a linear response to acetylcholine in a concentration range of 2.5 - 30 mM. Inhibition plots obtained from testing carbamate (carbofuran pesticides exhibited concentration dependent behaviour and showed linear profiles in concentration ranges between 5x10-8 - 5x10-7 M for carbofuran. The factors affecting the constructed optical biosensors were investigated.

Lyubov Yotova

2011-12-01

198

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

199

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

Science.gov (United States)

...treatment standards for hazardous wastes from the production of carbamates...residues that become hazardous wastes when they are discarded or...order to confirm detection and quantification of that chemical. RCRA LDR-related...land disposal of hazardous wastes unless wastes meet...

2011-06-13

200

Gold(I)-Catalyzed Enantioselective Intramolecular Dehydrative Amination of Allylic Alcohols with Carbamates  

OpenAIRE

A 1:2 mixture of [(S)-2](AuCl)2 [(S)-2 = (S)-DTBM-MeOBIPHEP] and AgClO4 catalyzes the intramolecular enantioselective dehydrative amination of allylic alcohols with carbamates to form five- and six-membered aliphatic nitrogen heterocycles in high yield with up to 95% ee.

Mukherjee, Paramita; Widenhoefer, Ross A.

2012-01-01

201

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

Science.gov (United States)

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

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

2014-07-21

202

Presence of organophosphorus pesticide oxygen analogs in air samples  

OpenAIRE

A number of recent toxicity studies have highlighted the increased potency of oxygen analogs (oxons) of several organophosphorus (OP) pesticides. These findings were a major concern after environmental oxons were identified in environmental samples from air and surfaces following agricultural spray applications in California and Washington State. This paper reports on the validity of oxygen analog measurements in air samples for the OP pesticide, chlorpyrifos. Controlled environmental and lab...

Armstrong, Jenna L.; Fenske, Richard A.; Yost, Michael G.; Galvin, Kit; Tchong-french, Maria; Yu, Jianbo

2013-01-01

203

Application of Multi-Analyte Methods for Pesticide Formulations  

International Nuclear Information System (INIS)

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

204

Solid-phase extraction for multi-residue analysis of pesticides in honey.  

Science.gov (United States)

A fast and simple multi-residue method for the analysis of 15 organophosphorus (OP), 17 organochlorine (OC), 8 pyrethroids (PYR), 12 N-methyl-carbamate (NMC) pesticide residues and bromopropylate in honey is presented. Ready-to-use EXtrelutNT 20 column, eluted with dichloromethane, was used to extract the pesticide residues from the aqueous-acetone honey sample, obtaining a clean extract directly analyzable. Determination was carried out by gas chromatography (GC) coupled with flame photometric detector (FPD) for OP compounds and by GC coupled with mass spectrometry detector (MSD) for OC and PYR pesticides and bromopropylate. The NMC pesticides were analysed by liquid chromatography-double derivatization coupled with spectrofluorimetric detector (LC/DD/Fl). This method allows the determination of the 53 pesticide residues at low concentrations (0.0005-0.074 mg/kg) and can be used to assess the compliance with the Maximum Residues Levels (MRLs) set by the European Union. The performance of the method was evaluated and specificity, linearity, recovery, repeatability, reproducibility, limit of quantification (LOQ) and limit of detection (LOD) were determined. A good linearity (r(2)? 0.99) was found in the range 0.0005-0.074 mg/kg for the majority of the compounds studied. Most of the pesticides had recoveries in the range 70-103 % and values of relative standard deviation (RSD) pesticides investigated was from 0.0005 to 0.025 mg/kg while the LOD ranged from 0.0002 to 0.008 mg/kg. PMID:20936565

Amendola, Graziella; Pelosi, Patrizia; Dommarco, Roberto

2011-01-01

205

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

206

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

207

Assessment of environmental exposures from agricultural pesticides in childhood leukaemia studies: Challenges and opportunities  

International Nuclear Information System (INIS)

Pesticides are ubiquitous in environments of many rural communities due to drift from agricultural applications and home/garden use. Studies of childhood leukaemia predominantly relied on retrospective pesticide exposure assessment and parental recall of use or proximity to fields or pesticide applications. Sample size requirements mostly preclude the collection of individual-level exposure information, bio-markers or environmental measurements of pesticides prospectively in cohorts. Yet such measures can be used in nested case-control approaches or for validating exposure models that can be applied to large populations. Recently developed models incorporate geographic information system technology and environmental databases of pesticide and/or crop data to assess exposure. Models developed in California to estimate residential exposures are presented by linking addresses to agricultural pesticide application data and land-use maps. Results from exposure validation and simulation studies and exposure measurement error issues are discussed. (authors)

208

A study of neurologic symptoms on exposure to organophosphate pesticides in the children of agricultural workers  

Directory of Open Access Journals (Sweden)

Full Text Available Pesticides are used extensively throughout the world in agriculture and in pest control as well as for community health purposes. Organophosphate (OP pesticide self-poisoning is an important clinical problem in rural regions of the developing world that kills an estimated 200,000 people every year. Unintentional poisoning kills far fewer people but is an apparent problem in places where highly toxic OP pesticides are available. Neurologic dysfunction is the best documented health effect of pesticide exposure. High-level exposure has both acute and long-term neurologic signs and symptoms, and adverse effects have been reported in most type of pesticides, including organophosphate (OP, carbamate, organochlorine, and pyrethroid insecticides, herbicides, fungicides, and fumigants. Acute OP pesticide exposure can involve in wide range of both central and peripheral neurologic symptoms. Increased neurologic symptom prevalence may provide early evidence of neurologic dysfunctions, before clinically measurable signs are evident. In this study, we analyzed the cross-sectional data on neurologic signs and symptoms from 225 rural children, both males (n = 132 and females (n = 93 who were occupationally and paraoccupationally exposed to methyl OPs (dichlorvos, fenthion, malathion, methyl parathion and ethyl OPs (chlorpyrifos, diazinon, ethyl parathion as they belonged to agricultural families handling, mixing, and spraying the OP pesticides. The children completed a specially designed questionnaire (Q16 on neurologic symptoms associated with pesticide exposure with their parental help. A suitable reference group consisting of rural children (n = 50 never involved in pesticide handling (neither outdoor nor indoor belonging to similar socioeconomic strata included in the study to compare the prevalence of various neurologic symptoms between the two groups. Among all the neurologic self-reported symptoms, headache, watering in eyes, and burning sensation in eye/face were the most important clinical manifestations attributed to OP pesticide exposure. These symptoms could probably be the consequence of chronic effects of most pesticides on the central nervous system. The muscarinic symptoms reported the maximum prevalence of salivation (18.22%, whereas lacrimation was observed in 17.33% cases, followed by diarrhea in 9.33% cases. The nicotinic clinical manifestations of acute OP poisoning revealed excessive sweating in 13.78% cases and tremors in 9.3% cases followed by mydriasis in 8.4% exposed children. The characteristic cholinergic symptoms, such as insomnia, headache, muscle cramps, weakness, and anorexia were also reported by both male and female exposed children. The high frequency of neurologic symptoms observed in the study may be due to parasympathetic hyperactivity due to the accumulated ACh resulting from AChE inhibition.

Rastogi S

2010-01-01

209

Economic Evaluation of Health Cost of Pesticide Use: Willingness to Pay Method  

OpenAIRE

This study highlights the results of contingent valuation method to measure health cost of pesticide use from farmer’s point of view. Analysis shows that farmers have a positive willingness to pay for avoiding pesticide related health risks. Theoretical validity tests show that relevant indicators such as risk perception, previous experience of pesticide related poisoning, education and income are significant predictors for the Positive WTP. From the results it is evident tha...

Muhammad Khan, Muhammad Khan

2009-01-01

210

Health effects of pesticides  

OpenAIRE

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

Seth, P. K.

2003-01-01

211

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

212

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

International Nuclear Information System (INIS)

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

213

Brassinosteroids play a critical role in the regulation of pesticide metabolism in crop plants.  

Science.gov (United States)

Pesticide residues in agricultural produce pose a threat to human health worldwide. Although the detoxification mechanisms for xenobiotics have been extensively studied in mammalian cells, information about the regulation network in plants remains elusive. Here we show that brassinosteroids (BRs), a class of natural plant hormones, decreased residues of common organophosphorus, organochlorine and carbamate pesticides by 30-70% on tomato, rice, tea, broccoli, cucumber, strawberry, and other plants when treated externally. Genome-wide microarray analysis showed that fungicide chlorothalonil (CHT) and BR co-upregulated 301 genes, including a set of detoxifying genes encoding cytochrome P450, oxidoreductase, hydrolase and transferase in tomato plants. The level of BRs was closely related to the respiratory burst oxidase 1 (RBOH1)-encoded NADPH oxides-dependent H2O2 production, glutathione biosynthesis and the redox homeostasis, and the activity of glutathione S-transferase (GST). Gene silencing treatments showed that BRs decreased pesticide residues in plants likely by promoting their metabolism through a signaling pathway involving BRs-induced H2O2 production and cellular redox change. Our study provided a novel approach for minimizing pesticide residues in crops by exploiting plants' own detoxification mechanisms. PMID:25761674

Zhou, Yanhong; Xia, Xiaojian; Yu, Gaobo; Wang, Jitao; Wu, Jingxue; Wang, Mengmeng; Yang, Youxin; Shi, Kai; Yu, Yunlong; Chen, Zhixiang; Gan, Jay; Yu, Jingquan

2015-01-01

214

Brassinosteroids play a critical role in the regulation of pesticide metabolism in crop plants  

Science.gov (United States)

Pesticide residues in agricultural produce pose a threat to human health worldwide. Although the detoxification mechanisms for xenobiotics have been extensively studied in mammalian cells, information about the regulation network in plants remains elusive. Here we show that brassinosteroids (BRs), a class of natural plant hormones, decreased residues of common organophosphorus, organochlorine and carbamate pesticides by 30–70% on tomato, rice, tea, broccoli, cucumber, strawberry, and other plants when treated externally. Genome-wide microarray analysis showed that fungicide chlorothalonil (CHT) and BR co-upregulated 301 genes, including a set of detoxifying genes encoding cytochrome P450, oxidoreductase, hydrolase and transferase in tomato plants. The level of BRs was closely related to the respiratory burst oxidase 1 (RBOH1)-encoded NADPH oxides-dependent H2O2 production, glutathione biosynthesis and the redox homeostasis, and the activity of glutathione S-transferase (GST). Gene silencing treatments showed that BRs decreased pesticide residues in plants likely by promoting their metabolism through a signaling pathway involving BRs-induced H2O2 production and cellular redox change. Our study provided a novel approach for minimizing pesticide residues in crops by exploiting plants' own detoxification mechanisms. PMID:25761674

Zhou, Yanhong; Xia, Xiaojian; Yu, Gaobo; Wang, Jitao; Wu, Jingxue; Wang, Mengmeng; Yang, Youxin; Shi, Kai; Yu, Yunlong; Chen, Zhixiang; Gan, Jay; Yu, Jingquan

2015-01-01

215

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

216

Discovery of betamethasone 17alpha-carbamates as dissociated glucocorticoid receptor modulators in the rat.  

Science.gov (United States)

A series of betamethasone 17alpha-carbamates were designed, synthesized, and evaluated for their ability to dissociate the two main functions of the glucocorticoid receptor, that is, transactivation and transrepression, in rat cell lines. A number of alkyl substituted betamethasone 17alpha-carbamates were identified with excellent affinity for the glucocorticoid receptor (e.g., 7, GR IC(50) 5.1 nM) and indicated dissociated profiles in functional assays of transactivation (rat tyrosine aminotransferase, TAT, and rat glutamine synthetase, GS) and transrepression (human A549 cells, MMP-1 assay). Gratifyingly, the in-vivo profile of these compounds, for example, 7, also indicated potent anti-inflammatory activity with impaired effects on glucose, insulin, triglycerides, and body weight. Taken together, these results indicate that dissociated glucocorticoid receptor modulators can be identified in rodents. PMID:18691892

Ali, Amjad; Balkovec, James M; Greenlee, Mark; Hammond, Milton L; Rouen, Greg; Taylor, Gayle; Einstein, Monica; Ge, Lan; Harris, Georgianna; Kelly, Terri M; Mazur, Paul; Pandit, Shilpa; Santoro, Joseph; Sitlani, Ayesha; Wang, Chuanlin; Williamson, Joann; Forrest, Michael J; Carballo-Jane, Ester; Luell, Silvi; Lowitz, Karen; Visco, Denise

2008-08-15

217

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2009-06-15

218

Pesticide-Exposure Matrix  

Science.gov (United States)

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

219

Pesticides: Protecting Workers  

Science.gov (United States)

... to mitigate risks associated with the use of older pesticides while preserving their benefits. In many cases, EPA made significant changes to increase protection for workers as part of the reregistration process. More recently, ...

220

Synthesis of (-)-(S,S)-clemastine by invertive N --> C aryl migration in a lithiated carbamate.  

Science.gov (United States)

The first enantioselective synthesis of the antihistamine agent clemastine, as its (S,S)-stereoisomer, has been achieved by ether formation between a proline-derived chloroethylpyrrolidine and an enantiomerically enriched tertiary alcohol. The tertiary alcohol was formed from the carbamate derivative of alpha-methyl-p-chlorobenzyl alcohol by invertive aryl migration on lithiation. The (S,S)-stereochemistry of the product confirms the invertive nature of the rearrangement. PMID:20405879

Fournier, Anne M; Brown, Robert A; Farnaby, William; Miyatake-Ondozabal, Hideki; Clayden, Jonathan

2010-05-21

221

Structure-Activity Studies on Nematicidal Activity of Dialkyl Carbamates and Thiocarbamates  

OpenAIRE

In laboratory tests, 129 dialkyl carbamates of types ROC(O)NHR', RSC(O)NHR', and ROC(S)NHR' were tested in a screening bioassay against Panagrellus redivivus. The 10 most active were lethal at concentrations from 5 ppm down to ca. 1 ppm. Eight of these (the only ones active below 2.5 ppm) were thiolcarbamates (RSC(O)NHR'). Decyl N-methyhhiolcarbamate was also lethal to Meloidogyne incognita at approximately 1 ppm in direct contact tests.

Kochansky, Jan; Feldmesser, Julius

1989-01-01

222

Solubility improvement of an anthelmintic benzimidazole carbamate by association with dendrimers  

OpenAIRE

The improvement of aqueous solubility of methyl (5-[propylthio]-1H-benzimidazol-2-yl) carbamate, albendazole (ABZ) using polyamidoamine (PAMAM) dendrimers as solubility enhancers was investigated. Full generation PAMAM dendrimers with amine terminal groups, (G3), with hydroxyl terminal groups (G3OH) and half generation PAMAM dendrimers with carboxylate terminal groups (G2.5 and G3.5), were chosen for this study. The nature of dendrimer-ABZ association was investigated by UV absorption, fluore...

Ferna?ndez, L.; Sigal, E.; Otero, L.; Silber, J. J.; Santo, M.

2011-01-01

223

Enhanced cytotoxicity of benzimidazole carbamate derivatives and solubilisation by encapsulation in cucurbit[n]uril.  

Science.gov (United States)

The albendazole derivatives (2-methoxyethyl) 5-propylthio-1H-benzimidazole-2-yl carbamate (MEABZ), N1-(2-methoxyethoxycarbonyl)-2-amino-5-propylthiobenzimidazole and N1-(2-methoxyethoxycarbonyl)-2-amino-6-propylthiobenzimidazole (MEABZ isomers A and B) and (2-hydroxyethyl) 5-propylthio-1H-benzimidazole-2-yl carbamate (HEABZ) have been synthesised. The cytotoxicity of these compounds was evaluated against a human colorectal cancer cell line (HT-29) and a human prostate cancer cell line (PC-3). The results demonstrate MEABZ, a new benzimidazole, is up to ten times more cytotoxic than the parent drug albendazole, whereas the MEABZ isomers A and B and HEABZ show no activity. A comparison of the cytotoxicity of these compounds, relative to ABZ, provides structure-activity data for this important class of anticancer agents. The aqueous solubilities of MEABZ encapsulated in Q[n] have been determined by (1)H NMR spectroscopy. The aqueous solubility of MEABZ at a physiologically relevant pH increased by 1200-fold by encapsulation in Q[8], from 8 microM to 9.4 mM, while Q[6,7] encapsulation substantially increased the solubility to more than 2 mM. Encapsulation in Q[7] and Q[8] induced significant upfield shifts for the MEABZ propyl and benzimidazole resonances. The upfield shifts indicate that the propyl and benzimidazole protons are located within the Q[7] and Q[8] cavity upon encapsulation. By contrast, encapsulation in Q[6] induced large upfield shifts for the (1)H resonances from the carbamate functional group, indicating that MEABZ associates with Q[6] at its portals, with only the carbamate group binding within the cavity. PMID:20523944

Zhao, Yunjie; Pourgholami, Mohammad H; Morris, David L; Collins, J Grant; Day, Anthony I

2010-07-21

224

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

OpenAIRE

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

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

2010-01-01

225

Design, synthesis, and preliminary evaluation of doxazolidine carbamates as prodrugs activated by carboxylesterases.  

Science.gov (United States)

The synthesis and tumor cell growth inhibition by doxazolidine carbamate prodrugs are reported. The carbamates were designed for selective hydrolysis by one or more human carboxylesterases to release doxazolidine (Doxaz), the formaldehyde-oxazolidine of doxorubicin that cross-links DNA to trigger cell death. Simple butyl and pentyl, but not ethyl, carbamate prodrugs inhibited the growth of cancer cells that overexpress carboxylesterase CES1 (hCE1) and CES2 (hiCE). Relative CES1 and CES2 expression levels were determined by reverse transcription of the respective mRNAs, followed by polymerase chain reaction amplification. More complex structures with a p-aminobenzyl alcohol (PABA) self-eliminating spacer showed better growth inhibition (IC50=50 nM for Hep G2 liver cancer cells) while exhibiting reduced toxicity toward rat cardiomyocytes, relative to the parent drug doxorubicin. Pentyl 4-(N-doxazolidinylcarbonyloxymethyl)phenylcarbamate, the lead compound for further investigation, appears to be activated in Hep G2 cells that express both CES1 and CES2. PMID:17125253

Burkhart, David J; Barthel, Benjamin L; Post, Glen C; Kalet, Brian T; Nafie, Jordan W; Shoemaker, Richard K; Koch, Tad H

2006-11-30

226

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

227

Synthesis and biological activity of new salicylanilide N,N-disubstituted carbamates and thiocarbamates.  

Science.gov (United States)

The development of novel antimicrobial drugs represents a cutting edge research topic. In this study, 20 salicylanilide N,N-disubstituted carbamates and thiocarbamates were designed, synthesised and characterised by IR, (1)H NMR and (13)C NMR. The compounds were evaluated in vitro as potential antimicrobial agents against Mycobacterium tuberculosis and nontuberculous mycobacteria (Mycobacterium avium and Mycobacterium kansasii) as well as against eight bacterial and fungal strains. Additionally, we investigated the inhibitory effect of these compounds on mycobacterial isocitrate lyase and cellular toxicity. The minimum inhibitory concentrations (MICs) against mycobacteria were from 4 ?M for thiocarbamates and from 16 ?M for carbamates. Gram-positive bacteria, including methicillin-resistant Staphylococcus aureus, were inhibited with MICs from 0.49 ?M by thiocarbamates, whilst Gram-negative bacteria and most of the fungi did not display any significant susceptibility. All (thio)carbamates mildly inhibited isocitrate lyase (up to 22%) at a concentration of 10 ?M. The (thio)carbamoylation of the parent salicylanilides led to considerably decreased cytotoxicity and thus improved the selectivity indices (up to 175). These values indicate that some derivatives are attractive candidates for future research. PMID:24953953

Krátký, Martin; Volková, Marie; Novotná, Eva; Trejtnar, František; Stola?íková, Ji?ina; Vinšová, Jarmila

2014-08-01

228

Contact allergy and exposure patterns to thiurams and carbamates in consecutive patients.  

Science.gov (United States)

Sensitization to rubber is most often due to sensitization to thiurams. Positive patch test reactions to carbamates are less frequent, and usually only diagnosed in patients with positive patch test reactions to thiurams as well. The aim of the present study was to describe the relative frequency of sensitization to thiuram mix (TH mix) and zinc diethyldithiocarbamate (ZDC) in a population where the exposure to these chemicals from rubber gloves was previously studied and considered to be of approximately the same order of magnitude. The thiuram derivatives seemed to be the most important sensitized (frequency 2.8%) compared to ZDC (frequency 0.5%), which has been the most frequently reported sensitizer among the carbamates in rubber gloves. An interesting observation was that the probability that the patient was reacting to ZDC was strongly associated with the strength of the patch test reaction to TH mix. This observation may add a new aspect to the discussion about cross-reactivity versus concomitant sensitization of thiurams and carbamates. PMID:8917827

Knudsen, B B; Menné, T

1996-08-01

229

Development of an analytical strategy based on LC-MS/MS for the measurement of different classes of pesticides and theirs metabolites in meconium: application and characterisation of foetal exposure in France.  

Science.gov (United States)

It is important to evaluate the impact of pesticides on human health because exposure to these compounds has been linked to harmful effects in many research studies. This exposure may be particularly harmful during the early stages of development (e.g. the prenatal period). The aim of the present study was to develop an analytical strategy for quantifying a number of pesticides and their metabolites in meconium (the neonate's first faeces), in order to characterize the extent of foetal exposure. The meconium sample was dried and grinded in order to homogenize the sample, prior to solid-liquid extraction and a purification by solid-phase extraction using a weak anion mixed-mode polymeric sorbent. Analyte separation and quantification was performed by liquid chromatography coupled to electrospray-triple quadrupole mass spectrometry. Five pesticide families (carbamates, organophosphates, pyrethroids, phenylureas and phenoxy herbicides) and their metabolites could be quantified in meconium with limits of quantification ranging between 0.2 ng/g and 200 ng/g. This method was applied to a set of 171 meconium samples collected in the Picardie region of northern France. The highest prevalence was observed for metabolites of organophosphates and carbamates (57.9% and 22.8%, respectively). The parent pesticides were rarely present and were only found at very low concentrations, except for the pyrethroids cyfluthrin and cypermethrin, which were found in 7.6% of meconium samples at concentrations of between 43.8 and 480 ng/g. The most frequently detected contaminant was the organophosphate metabolite dimethyl thiophosphate detected in 49.1% of the samples and quantified with a median concentration of 344 ng/g. These data evidence significant foetal exposure to organophosphate pesticides, pyrethroids and carbamates. PMID:24834827

Berton, Thierry; Mayhoub, Flora; Chardon, Karen; Duca, Radu-Corneliu; Lestremau, Francois; Bach, Véronique; Tack, Karine

2014-07-01

230

Pesticides distribution in sediments of a tropical coastal lagoon adjacent to an irrigation district in northwest Mexico.  

Science.gov (United States)

This work presents the content of organochlorine (OCs) pesticides in sediments of both, agricultural drains from the Irrigation District 076, El Carrizo, Sinaloa, and of the adjacent coastal lagoon ecosystem of Agiabampo-Bacorehuis-Jitzamuri, located in northwest Mexico. A questionnaire was applied to the farmers of this irrigation district, to evaluate the usage of pesticides and to determine if banned OCs are still used. Around 31 tons of active ingredients were applied in the autumn-winter cycle (1997-1998). There were eighteen different pesticides; of them 61% are insecticides, 28% herbicides, 6% fungicides and 6% other compounds. Around 73% of the pesticides applied are organophosphorus, carbamates and sulfur, OCs are still applied and represent 4% of the total. All the pesticides applied in the irrigation district are authorized in the Official Pesticide Catalog, nevertheless forbidden and restricted compounds were detected in the sediment samples. The presence of heptachlor, heptachlor epoxide, alpha-endosulfan, beta-endosulfan, endosulfan sulfate, alpha-HCH, beta-HCH, lindane, delta-HCH, aldrin, dieldrin p,p'-DDT, p,p'-DDE and p,p'-DDD was recorded in the sediment sample. The analysis of the sediments suggest that the principal pesticides input to the coastal ecosystem is mainly through three of the seven agricultural drains, that collect the excess irrigation water and runoff from the district surface. A gradient of pesticide residues in sediments exists from the agricultural drains (52 ng OCs g(-1) dry weight) to the Jitzamuri bay (32 ng OCs g(-1) dry weight). PMID:12472155

González-Farias, F; Cisneros Estrada, X; Fuentes Ruíz, C; Díaz González, G; Botello, A V

2002-11-01

231

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 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

232

Pesticides in the propolis at São Saulo State, Brazil=Pesticidas na própolis do Estado de São Paulo, Brasil  

Directory of Open Access Journals (Sweden)

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.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 presença 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.

Silvia Maria Alves Gomes

2012-10-01

233

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

234

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

235

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.

236

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

237

77 FR 74003 - Pesticides; Draft Guidance for Pesticide Registrants on Antimicrobial Pesticide Products With...  

Science.gov (United States)

...mold-related'' pesticide products. Mold-related pesticides are antimicrobial...label claim to inhibit or destroy mold or mildew growth on hard, nonporous and porous surfaces...hereinafter referred to as ``mold-related...

2012-12-12

238

Absorption of carbon dioxide and isotope exchange rate of carbon in a reaction system between carbon dioxide and carbamic acid  

International Nuclear Information System (INIS)

The performance of isotope separation of carbon-13 by chemical exchange between carbon dioxide and carbamic acid was studied. The working fluid used in the study was a solution of DNBA, (C4H9)2NH and n-octane mixture. Factors related to the isotope exchange rate were measured, such as the absorption rate of carbon dioxide into the solution of DNBA and n-octane, the isotope exchange rate and the separation factor in the reaction between CO2 and carbamic acid. The absorption of CO2 into the working fluid was the sum of chemical absorption by DNBA and physical absorption by n-octane. The absorption of carbon dioxide into the working fluid was negligible at temperatures over 90 0C, but increased gradually at lower temperatures. Carbon dioxide was absorbed into DNBA by chemical absorption, and DNBA was converted to carbamic acid by the reaction. The reaction for synthesis and decomposition of carbamic acid was reversible. The separation factor in equilibrium reached a large value at lower temperatures. The isotope exchange rate between gas and liquid was proportional to the product of the concentration of carbamic acid and the concentration of CO2 by physical absorption. The isotope separation of carbon by chemical exchange reaction is better operated under the conditions of lower temperature and higher pressure. (author)

239

Pesticide Action Network UK  

Science.gov (United States)

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

240

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

241

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.

242

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

Science.gov (United States)

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

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

2014-02-01

243

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

244

Ab initio study of CO2 capture mechanisms in aqueous monoethanolamine: reaction pathways for the direct interconversion of carbamate and bicarbonate.  

Science.gov (United States)

Ab initio molecular orbital calculations combined with the polarizable continuum model (PCM) formalism have been carried out for a comprehensive understanding of the mechanism of carbon dioxide (CO2) absorption by aqueous amine solutions. CO2 is captured by amines to generate carbamates and bicarbonate. We have examined the direct interconversion pathways of these two species (collectively represented by a reversible hydrolysis of carbamate) with the prototypical amine, monoethanolamine (MEA). We evaluate both a concerted and a stepwise mechanism for the neutral hydrolysis of MEA carbamate. Large activation energies (ca. 36 kcal/mol) and lack of increase in catalytic efficiency with the inclusion of additional water molecules are predicted in both the mechanisms. We also examined the mechanism of alkaline hydrolysis of MEA carbamate at high concentrations of amine (high pH). The addition of OH(-) ion to carbamate anion was theoretically not allowed due to the reduction in the nucleophilicity of the former as a result of microsolvation. We propose an alternative pathway for hydrolysis: a proton transfer from protonated MEA to carbamate to generate the carbamic acid that initially undergoes a nucleophilic addition of OH(-) and subsequent low-barrier reactions leading to the formation of bicarbonate and free MEA. On the basis of the calculated activation energies, this pathway would be the most efficient route for the direct interconversion of carbamate and bicarbonate without the intermediacy of the free CO2, while the actual contributions will be dependent on the concentrations of protonated MEA and OH(-) ions. PMID:24003832

Matsuzaki, Yoichi; Yamada, Hidetaka; Chowdhury, Firoz A; Higashii, Takayuki; Onoda, Masami

2013-09-26

245

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

Science.gov (United States)

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

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

2013-04-01

246

[Susceptibility of cockroaches Blattella germanica L. collected from hospitals to selected pyrethroid and carbamate insecticides].  

Science.gov (United States)

The resistance to four pyrethroid insecticides: permethrin, deltamethrin, cypermethrin, etofenprox, and to two carbamate insecticides--bendiocarb, propoxur was investigated on field strains of German cockroaches (Blatella germanica L.) caught in hospitals from various parts of Poland. The tests were carried out only on males by the contact method recommended by the WHO. The resistance was evaluated on the basis of LT50S and resistance ratios (RRs). The tested fields strains showed high or moderate resistance to permethrin, deltamethrin, cypermethrin and bendiocarb: moderate resistance or tolerance to etofenproks (this compound has been never used in Poland before), and tolerance or susceptibility to propoxur. PMID:9026900

Gliniewicz, A; Krzemi?ska, A; Sawicka, B

1996-01-01

247

Salicylanilide carbamates: antitubercular agents active against multidrug-resistant Mycobacterium tuberculosis strains.  

Science.gov (United States)

A series of 27 salicylanilide-based carbamates was prepared as a part of our ongoing search for new antituberculosis drugs. These compounds exhibited very good in vitro activity against Mycobacterium tuberculosis, Mycobacterium kansasii and Mycobacterium avium and, in particular, against five multidrug-resistant strains, with MIC values between 0.5-2 micromol/L. Moreover, they displayed moderate toxicity against intestinal cells with the selectivity index being up to 96. Furthermore, acid stability and a half-life of 43h at pH 7.4 were shown. Thus, these novel salicylanilide derivatives are drug candidates which should be seriously consider for further screening. PMID:20060303

Férriz, Juana M; Vávrová, Katerina; Kunc, Filip; Imramovský, Ales; Stolaríková, Jirina; Vavríková, Eva; Vinsová, Jarmila

2010-02-01

248

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

OpenAIRE

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 duratio...

Muthuviveganandavel, V.; Muthuraman, P.; Muthu, S.; Srikumar, K.

2011-01-01

249

ELISA as an affordable methodology for monitoring groundwater contamination by pesticides in low-income countries.  

Science.gov (United States)

The traditional instrumental technology for pesticide residue analysis is too expensive and labor-intense to meet the regional needs concerning environmental monitoring. ELISA methodology was used for a pilot scale study of groundwater quality in an agricultural region a few kilometers southwest of Montevideo, the capital city of Uruguay. The study spanned 2 years and examined concentrations (detection limits are given in [ppb]) of two triazine herbicides (simazine [0.3] and atrazine [0.4]) and the carbamate insecticide carbaryl [10] and its major metabolite 1-naphthol [17]. In general, pesticide concentrations were below detection limits in the samples tested and in all cases were well below the maximum contaminant levels set by the U.S. EPA. 1-Naphthol was detected frequently by ELISA, but the assay may have tended to systematically overestimate this analyte. To our knowledge, this is the first study of its type in Uruguay and perhaps the first systematic approach to monitoring for organic pesticides in groundwater water sources in the temperate region of South America. PMID:15984762

Brena, Beatriz M; Arellano, Lourdes; Rufo, Caterina; Last, Michael S; Montaño, Jorge; Egaña Cerni, Eduardo; Gonzalez-Sapienza, Gualberto; Last, Jerold A

2005-06-01

250

Development of a method for extraction and assay of human erythrocyte acetylcholinesterase and pesticide inhibition.  

Science.gov (United States)

A method of extracting membranes from red blood cells (RBCs) is described, which were in turn used to assay acetylcholinesterase (AChE) activity. The evidence for the enzyme activity was established by selective inhibition using 1,5-bis(4-allyldimethylammoniumphenyl) pentan-3-one dibromide, tetraisopropyl pyrophosphoramide and neostigmine. Blood samples were exposed to three organophosphorus (dichlorvos, chlorpyrifos and diazinon) and two carbamate (carbaryl and carbofuran) pesticides. Afterwards AChE activities in RBC membranes were determined. The concentrations capable to inhibit the enzyme activity by 50% (IC??) for the pesticides were 10.66 µM (dichlorvos), 21.42 µM (chlorpyrifos), 109.98 µM (carbaryl) and 5.44 µM (carbofuran). The results related to 20% enzyme inhibition (level used in the estimation of threshold limits for anticholinesterase compounds) were below those acceptable daily intake values enacted by relevant national and international regulations. These results suggest that the proposed AChE extraction from RBC and assay could be a suitable method for monitoring occupational exposure to pesticides. PMID:23632007

Linhares, A G; Assis, C R D; Siqueira, M T; Bezerra, R S; Carvalho, L B

2013-08-01

251

Illegal Pesticide Products  

Science.gov (United States)

... Versions imported from such countries as England and Australia often give doses in metric units, which can cause Americans to accidentally over-dose or under-dose pets. Read more about counterfeit pesticide products for dogs and cats . Retailer information about ...

252

Comparative Evaluation of High Protein against Normal Protein Diet in Combination with Carbamates against Organophosphorus Intoxication in Rats  

Directory of Open Access Journals (Sweden)

Full Text Available The relative efficacy of an isocaloric high (HPD containing 59 per cent protein, in comparison to a conventional diet containing 21 per cent protein as applied in the alleviation of toxicity of diisopropyl phosphorofluoridate (DFP and methyl isopropyl phosphonofluoridate (sarin, has been reported. In combination with well-known prophylactics like carbamates and cholinolytics like atropine against nerve gas toxicity, HPD appears to be superior to the conventional diet as studied by survival time measurements. Apart from carbamates, atropine and mecamylamine, HPD may be treated as an additional prophylactic agent to guard against the toxicity of DFP and sarin, which are being used as war chemicals.

A. K. Chatterjee

2013-04-01

253

2-(4-Methyl­cyclo­hex-3-en­yl)propan-2-yl N-phenyl­carbamate  

OpenAIRE

In the title carbamate compound, C17H23NO2, one of the Csp 3 atoms of the cyclo­hexene ring is disordered over two sites with refined occupancies of 0.55?(2) and 0.45?(2), both disorder components resulting in half-boat conformations. The mean plane through the carbamate unit is inclined at inter­planar angles of 14.80?(13), 18.30?(17) and 24.0?(2)°, respectively, with respect to the phenyl ring, and the major and minor disorder component cyclo­hexene rings. In...

Ghalib, Raza Murad; Sulaiman, Othman; Mehdi, Sayed Hasan; Goh, Jia Hao; Fun, Hoong-kun

2010-01-01

254

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

Science.gov (United States)

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

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

2002-05-01

255

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

256

Resistance to selected organochlorin, organophosphate, carbamate and pyrethroid, in Spodoptera litura (Lepidoptera: Noctuidae) from Pakistan.  

Science.gov (United States)

The toxicity of the most commonly used insecticides of organochlorine, organophosphate, pyrethroid, and carbamate groups were investigated against Spodoptera litura (F.) (Lepidoptera: Noctuidae) populations collected for three consecutive years (2004-2006). For a chlorocyclodiene and pyrethroids tested, the resistance ratios compared with Lab-PK were in the range of 10- to 92-fold for endosulfan, 5- to 111-fold for cypermethrin, 2- to 98-fold for deltamethrin, and 7- to 86-fold for beta-cyfluthrin. For organophosphates and carbamates, resistance ratios were in the range of 3- to 169-fold for profenofos, 18- to 421-fold for chlorpyrifos, 3- to 160-fold for quinalphos, 6- to 126-fold for phoxim, 7- to 463-fold for triazophos, and 10- to 389-fold for methomyl and 16- to 200-fold for thiodicarb. Resistance ratios were generally low to medium for deltamethrin and beta-cyfluthrin and high to very high for endosulfan, cypermethrin, profenofos, chlorpyrifos, quinalphos, phoxim, triazophos, methomyl, or thiodicarb. Pairwise comparisons of the log LC50 values of insecticides tested for all the populations showed correlations among several insecticides, suggesting a cross-resistance mechanism. Integration of timely judgment of pest problem, delimiting growing of alternate crops such as arum, rotation of insecticides with new chemicals, and insect growth regulators in relation to integrated pest management could help in manageable control of this important pest. PMID:18950050

Saleem, Mushtaq A; Ahmad, Munir; Ahmad, Mushtaq; Aslam, Muhammad; Sayyed, Ali H

2008-10-01

257

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 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.

258

Gas Chromatographic Methodology for the Determination of Some Halogenated Pesticides  

OpenAIRE

A Gas Chromatography (GC) methodology has been validated for the determination of some halogenated pesticides. Complete separation of the pesticide prepared in ethyl acetate was achieved on Rtx - 1 column with dimension, 30m x 0.25mm x 0.25:m. The GC equipped with electron capture detector was run using column temperature programmed from 80ºC (2 min) to 200ºC (15 min) at the rate of 4ºC/min giving a total analysis time of 47 min. The detector and injector were respectively at temperatures ...

Samuel Afful; Ewusie, E. Enimil B. Blewu G. Adjei Mantey And E. A.

2010-01-01

259

PESTICIDE SCREENING RESULTS FROM EIGHT DAYCARE CENTERS  

Science.gov (United States)

To improve assessments of children's exposures to pesticides in support of the Food Quality Protection Act, priority research and data needs include: pesticide use patterns, pesticide residue distributions, and dermal exposure assessment approaches. To address these gaps, the ...

260

77 FR 27130 - Ametoctradin; Pesticide Tolerances  

Science.gov (United States)

...FRL-9339-6] Ametoctradin; Pesticide Tolerances AGENCY: Environmental...Division (7505P), Office of Pesticide Programs, Environmental Protection...registration in the USA, Australia, and Canada and import tolerance...proposed by the Agency, the Pesticide Management Regulatory...

2012-05-09

261

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

262

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

Science.gov (United States)

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

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

2007-02-01

263

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

264

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)

265

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

Science.gov (United States)

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

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

2011-08-01

266

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

267

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

268

Solubility improvement of an anthelmintic benzimidazole carbamate by association with dendrimers  

Directory of Open Access Journals (Sweden)

Full Text Available The improvement of aqueous solubility of methyl (5-[propylthio]-1H-benzimidazol-2-yl carbamate, albendazole (ABZ using polyamidoamine (PAMAM dendrimers as solubility enhancers was investigated. Full generation PAMAM dendrimers with amine terminal groups, (G3, with hydroxyl terminal groups (G3OH and half generation PAMAM dendrimers with carboxylate terminal groups (G2.5 and G3.5, were chosen for this study. The nature of dendrimer-ABZ association was investigated by UV absorption, 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.

L. Fernández

2011-12-01

269

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)

270

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.

2007-03-01

271

Determination of pesticide in ground and surface water samples and perception of farmers about pesticides in Sindh  

International Nuclear Information System (INIS)

The continuous monitoring of pesticide residues in our food, drinking water, environment and biosphere at large is needed for creating awareness for the trends of level of contamination and building up a data base upon which, future plan could be decided. In this paper monitoring requirements regarding the instrumentations, valid sampling, analytical protocols and its purpose are discussed in detail. Twenty nine water samples were analyzed and 22 were found contaminated with detectable level of 5 pesticides. These samples were found contaminated in the range of 0.0005-0.054 micro g/L. The percentage of detection of Chloropyriphos, Malathion, Dimethoate, Cypermethrin, and Endosulfan was respectively 7%, 14%. 17.8%, 35.8% and 25%. However, none of the samples were found above their Maximum Acceptable Concentrate (MAC) i.e. 0.1 micro g/L and 0.5 micro g/L for single and number of insecticides respectively set by EEC (European Economic Commission). Moreover, a survey of farmers' perceptions in respect of effects on their health with pesticide exposure was conducted to find out farmers' perception for the use of pesticides and how these may affect on their health with, identification of key issues those are relevant to farmers' health for further training to increase farmer's awareness about the use of pesticides. (author)

272

Quality control of pesticide products  

International Nuclear Information System (INIS)

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

273

Determination of ethyl carbamate in fermented liquids by ultra high performance liquid chromatography coupled with a Q Exactive hybrid quadrupole-orbitrap mass spectrometer.  

Science.gov (United States)

In this study, the determination of ethyl carbamate (EC) in fermented liquids (red wines, Chinese liquors and yellow wines) was carried by using ultra high performance liquid chromatography coupled with a Q Exactive hybrid quadrupole-orbitrap mass spectrometer (UHPLC-MS/MS). The parameters usually examined in the method validation were firstly evaluated. Good linearity was obtained with a correlation coefficient of 0.9999. The limits of detection (LOD) and quantitation (LOQ) of EC in sample were 1.8 and 4.0 ?g/L, respectively. Recoveries ranged between 107.19% and 110.98%. The precision (relative standard deviation, RSD) of the method was <5%. Furthermore, red wines, Chinese liquors and yellow wines for sale were detected using this method. The results showed that the red wines and Chinese liquors had the normal EC level that was within the limits of the Canadian legislation. The proposed method was simple in sample preparation without using organic solvents in pre-treatment and could be used for the determination of the content of EC in fermented liquids. PMID:25660859

Zhao, Xirong; Jiang, Changxing

2015-06-15

274

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 (L(ij)) represent the interactions between the drug (d(i)) and the target (t(j)), characterized by different experimental measures (K(i), K(m), IC50, etc.) obtained in pharmacological assays under diverse boundary conditions (c(j)). 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 Durán, Francisco J; Alonso, Nerea; Caamaño, Olga; García-Mera, Xerardo; Yañez, Matilde; Prado-Prado, Francisco J; González-Díaz, Humberto

2014-01-01

275

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

276

The Greening of Pesticide–Environment Interactions: Some Personal Observations  

OpenAIRE

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

277

PESTICIDE APPLICATION TECHNICS IMPROVEMENT  

Directory of Open Access Journals (Sweden)

Full Text Available The academic textbook Pesticide application tehnics improvement is the result of several-year recording theoretical models, numerous practical tests, and data collection relating to technical systems in plant protection and its environment in the narrowest sense. In this first edition, the authors cover the area they have dealt with for many years. The authors aimed to present complete and clear methods how to solve specific problems in the agricultural practice management, plant protection, and direct practice application – ‘‘Know- How'', with as many as possible useful data. References used, along with local ones, are mostly American and from Western Europe. This textbook is intended for those who already use the agricultural technique in plant protection and those who are just acquiring the basics of technical systems proper application in daily practice, regardless the size of the agricultural farm. The authors covered in details and explained some bases of physics logic, analysis, and synthesis of specific laws while using pesticides due to extremely importance in understanding the problem area.

?uro Banaj

2011-06-01

278

Investigation of preconcentration strategies for the trace analysis of multi-residue pesticides in real samples by capillary electrophoresis.  

Science.gov (United States)

In this work, on-line preconcentration strategies were investigated for the multi-residue analysis of pesticides in drinking water and vegetables using micellar electrokinetic chromatography. Among the on-line strategies, sweeping and stacking with reverse migration of micelles (SRMM), with and without the insertion of a plug of water before sample injection, were contrasted. A new version of SRMM was also introduced. The modification consisted of momentarily applying a positive voltage at the inlet vial right after sample has been injected, increasing the efficiency by which the analytes are captured. Nine pesticides from different classes, carbendazim (benzimidazole), simazine, atrazine, propazine and ametryn (triazine), diuron and linuron (urea), carbaryl and propoxur (carbamate), were baseline separated in less than 6 min with a electrolyte composed of 20 mmol l(-1) phosphate buffer at pH 2.5, containing 25 mmol l(-1) sodium dodecyl sulfate and 10% methanol. Limits of detection (LODs) in the order of 2-46 microg l(-1) for the pesticides under investigation were obtained solely using the on-line strategies. Enrichment factors of 3-18-fold were obtained. These factors were computed as the improvement of the concentration LODs with respect to the reference condition (injection of 10 s at 2.5 kPa pressure). The proposed methodologies were applied to the analysis of pesticides in complex matrices such as carrot extracts where the detection of 2.5 microg l(-1) was illustrated. By combining off-line solid-phase extraction and the proposed on-line strategies, the detection of pesticides in drinking water at the 0.1 microg l(-1) level was conceived. PMID:14558617

da Silva, Clóvis L; de Lima, Elizabete C; Tavares, Marina F M

2003-10-01

279

Cholinesterase activities and sensitivity to pesticides in different tissues of silver European eel, Anguilla anguilla.  

Science.gov (United States)

Cholinesterase (ChE) activities were characterized in silver European eel, Anguilla anguilla, grown in the brackish lagoon of Comacchio (Italy). All specimens were harvested at the "lavoriero", a traditional eel trapping weir that captures eels while leaving internal waters at the onset of reproductive migration. To our knowledge, no investigation on ChE was reported in silver eels. Therefore a first characterization of enzyme activity in muscle, brain, liver and plasma of silver eel was carried out, in the presence of different substrates, selective inhibitors, and four pesticides representative of the carbamate and organophosphate classes. Brain and white skeletal muscle showed similar ChE activities, 5- and 10-fold higher than those detected in liver and plasma, respectively. Km values of 0.31 and 0.30 mM, and Vmax values of 40.28 and 35.47 nmol min(-1) mg protein(-1) were obtained in brain and muscle ChE, respectively. Acetycholinesterase was the predominant ChE form in all tissues, as concluded by comparing the effects of BW 284c51, iso-OMPA and eserine. ChE activities in brain and muscle were significantly inhibited by in vitro treatment with pesticides, with the following order of potency: carbofuran>carbaryl>chlorpyrifos?diazinon. PMID:21777695

Valbonesi, P; Brunelli, F; Mattioli, M; Rossi, T; Fabbri, E

2011-11-01

280

Structure-genotoxic activity relationships of pesticides: comparison of the results from several short-term assays.  

Science.gov (United States)

The Computer-Automated Structure Evaluation (CASE) program has been applied to the analysis of the genotoxic activity of 54 pesticides (31 insecticides, 15 herbicides and 8 fungicides) in 5 different short-term test systems measuring gene mutation and DNA damage. The database contains compounds presenting diverse structures including carbamates, thiocarbamates, organophosphates, halo-aromatics and other functionalities. Some significant relationships between common structural features and the genotoxic activity displayed by these chemicals have been found. Among the most relevant fragments, automatically selected by the program, a methoxyphosphinyl and a chlorovinyl group appear as the common structural subunits responsible for the activities detected in the battery composed of the Salmonella typhimurium histidine reversion assay, the mouse lymphoma gene mutation assay and recombination in the yeast Saccharomyces cerevisiae. PMID:3932848

Klopman, G; Contreras, R; Rosenkranz, H S; Waters, M D

1985-12-01

281

Managing insecticide resistance in malaria vectors by combining carbamate-treated plastic wall sheeting and pyrethroid-treated bed nets  

OpenAIRE

Abstract Background Pyrethroid resistance is now widespread in Anopheles gambiae, the major vector for malaria in sub-Saharan Africa. This resistance may compromise malaria vector control strategies that are currently in use in endemic areas. In this context, a new tool for management of resistant mosquitoes based on the combination of a pyrethroid-treated bed net and carbamate-treated plastic sheeting was developed. Methods In the laboratory, the insecticidal activity and wash resistance of ...

Pennetier Cédric; Irish Seth; Baldet Thierry; Chabi Joseph; Djènontin Armel; Hougard Jean-Marc; Corbel Vincent; Akogbéto Martin; Chandre Fabrice

2009-01-01

282

Covalent Inhibition of Recombinant Human Carboxylesterase 1 and 2 and Monoacylglycerol Lipase by the Carbamates JZL184 and URB597  

OpenAIRE

Carboxylesterase type 1 (CES1) and CES2 are serine hydrolases located in the liver and small intestine. CES1 and CES2 actively participate in the metabolism of several pharmaceuticals. Recently, carbamate compounds were developed to inhibit members of the serine hydrolase family via covalent modification of the active site serine. URB597 and JZL184 inhibit fatty acid amide hydrolase (FAAH) and monoacylglycerol lipase (MAGL), respectively; however, carboxylesterases in liver have been identifi...

Crow, J. Allen; Bittles, Victoria; Borazjani, Abdolsamad; Potter, Philip M.; Ross, Matthew K.

2012-01-01

283

Movement of pesticides from the site of application  

International Nuclear Information System (INIS)

Important among the data needed to reduce the environmental risks potentially associated with pesticide use is a clear understanding of environmental processes. Much information has been accumulated and this is discussed with special reference to the research being carried out by scientists of the Agricultural Research Service of the United States Department of Agriculture at Beltsville. Physical and chemical properties are important in predicting the environmental fate of a pesticide. Routes of dissipation from the site of application will be influenced by the agricultural system and the method of application. Causes of loss include runoff and a three year study showed the extent of herbicide runoff to the Wye River Estuary. Potential contamination of groundwater by leaching has been recognized as a problem in certain cases and its extent and causes are being extensively studied. Volatilization may be a significant source of loss. Two important factors are the vapour pressure of the pesticide and the nature of the surface. Pesticide volatilization was measured using specially designed sampling equipment. Losses from dry soil surfaces were much smaller than the rapid losses from moist surfaces. Losses were predictable in terms of the vapour pressure of the compound and its interaction with surfaces. Atmospheric movement is important in the transport of pesticides. They may be redeposited on the Earth's surface by a number of mechanisms including rainfall, fog and snowechanisms including rainfall, fog and snow or be adsorbed on particulate matter. A specially constructed sampler was used to collect the liquid and vapour phases of fog. Pesticides, their alteration products, plasticizers, flame retardants, industrial chemicals and combustion products were found in fog samples collected in Maryland and California. Distribution between liquid and vapour phases was not in accordance with Henry's Law and experiments are in progress to measure Henry's Law constants to validate these observations. 26 refs, 2 figs, 3 tabs

284

Non-Hodgkin lymphoma and occupational exposure to agricultural pesticide chemical groups and active ingredients: a systematic review and meta-analysis.  

Science.gov (United States)

This paper describes results from a systematic review and a series of meta-analyses of nearly three decades worth of epidemiologic research on the relationship between non-Hodgkin lymphoma (NHL) and occupational exposure to agricultural pesticide active ingredients and chemical groups. Estimates of associations of NHL with 21 pesticide chemical groups and 80 active ingredients were extracted from 44 papers, all of which reported results from analyses of studies conducted in high-income countries. Random effects meta-analyses showed that phenoxy herbicides, carbamate insecticides, organophosphorus insecticides and the active ingredient lindane, an organochlorine insecticide, were positively associated with NHL. In a handful of papers, associations between pesticides and NHL subtypes were reported; B cell lymphoma was positively associated with phenoxy herbicides and the organophosphorus herbicide glyphosate. Diffuse large B-cell lymphoma was positively associated with phenoxy herbicide exposure. Despite compelling evidence that NHL is associated with certain chemicals, this review indicates the need for investigations of a larger variety of pesticides in more geographic areas, especially in low- and middle-income countries, which, despite producing a large portion of the world's agriculture, were missing in the literature that were reviewed. PMID:24762670

Schinasi, Leah; Leon, Maria E

2014-04-01

285

Determination of mineral, trace element, and pesticide levels in honey samples originating from different regions of Malaysia compared to manuka honey.  

Science.gov (United States)

The present study was undertaken to determine the content of six minerals, five trace elements, and ten pesticide residues in honeys originating from different regions of Malaysia. Calcium (Ca), magnesium (Mg), iron (Fe), and zinc (Zn) were analyzed by flame atomic absorption spectrometry (FAAS), while sodium (Na) and potassium (K) were analyzed by flame emission spectrometry (FAES). Trace elements such as arsenic (As), lead (Pb), cadmium (Cd), copper (Cu), and cobalt (Co) were analyzed by graphite furnace atomic absorption spectrometry (GFAAS) following the microwave digestion of honey. High mineral contents were observed in the investigated honeys with K, Na, Ca, and Fe being the most abundant elements (mean concentrations of 1349.34, 236.80, 183.67, and 162.31?mg/kg, resp.). The concentrations of the trace elements were within the recommended limits, indicating that the honeys were of good quality. Principal component analysis reveals good discrimination between the different honey samples. The pesticide analysis for the presence of organophosphorus and carbamates was performed by high performance liquid chromatography (HPLC). No pesticide residues were detected in any of the investigated honey samples, indicating that the honeys were pure. Our study reveals that Malaysian honeys are rich sources of minerals with trace elements present within permissible limits and that they are free from pesticide contamination. PMID:24982869

Moniruzzaman, Mohammed; Chowdhury, Muhammed Alamgir Zaman; Rahman, Mohammad Abdur; Sulaiman, Siti Amrah; Gan, Siew Hua

2014-01-01

286

Isotope separation of carbon-13 by counter-current column with exchange reaction between carbon dioxide and carbamic acid  

International Nuclear Information System (INIS)

The isotope separation performance of carbon-13 with exchange reaction between CO2 and carbamic acid was studied and some factors for the counter-current column were studied for improving the overall performance. The working fluid for the experiments was a solution of DNBA, (C4H9)2NH, and n-octane mixture. The rate-controlling step of 13C transfer at temperatures higher than 10 deg C was the exchange reaction between carbamic acid and CO2 dissolved by physical absorption. The capacity coefficient of 13C transfer between gas and liquid in the counter-current column was successfully related to the product of three factors: the concentration of carbamic acid, the concentration of CO2 dissolved by physical absorption and the liquid holdup of the column. The liquid holdup was also an important factor. As the holdup increased, the isotope exchange rate and the overall separation factor of the column increased. However, the transient time to equilibrium was much longer. (author)

287

Estrogenic and esterase-inhibiting potency in rainwater in relation to pesticide concentrations, sampling season and location  

Energy Technology Data Exchange (ETDEWEB)

Estrogenic potency of rainwater correlated well with organochlorine concentrations, but could not be attributed to specific pesticides. - In a year-round monitoring program (1998), pesticide composition and toxic potency of the mix of pollutants present in rainwater were measured. The goal of the study was to relate atmospheric deposition of toxic potency and pesticide composition to each other and to sampling period and local agricultural activity. Rainwater was collected in 26 consecutive periods of 14 days in a background location (BACK) and in two locations representative for different agricultural practices, i.e. intensive greenhouse horticulture (HORT) and flower bulb culture (BULB). Samples were chemically analyzed for carbamate (CARB), organophosphate (OP) and organochlorine (OC) pesticides and metabolites. Esterase inhibiting potency of rainwater extracts was measured in a specially developed bio-assay with honeybee esterases and was expressed as an equivalent concentration of the model inhibitor dichlorvos. Estrogenic potency of the extracts was measured in the ER-CALUX reporter gene assay and was expressed as an equivalent concentration of estradiol. Multivariate principal component analysis (PCA) techniques proved to be valuable tools to analyze the numerous pesticide concentrations in relation to toxic potency, sampling location, and sampling season. Pesticide composition in rainwater depended much more on sampling season than on sampling location, but differences between SPRING and SUMMER were mainly attributed to local differences in agricultural practice. On average, the esterase inhibiting potency exceeded the maximum permissible concentration set for dichlorvos in The Netherlands, and was significantly higher in HORT than in BACK and BULB. Esterase inhibition correlated significantly with OP and CARB concentrations, as expected given the working mechanism of these insecticides. The estrogenic potency incidentally exceeded NOEC levels reported for aquatic organisms and was highest in SPRING. Although estrogenic potency of rainwater correlated with OC concentrations, the ER-CALUX responses could not be attributed to any particular pesticides. Besides, the contribution of non-analyzed xeno-estrogens as alkylphenol(-ethoxylates) and bisphenol-A to the estrogenic potency of rainwater could not be excluded. Further research should focus on the chemical identification of estrogenic compounds in rainwater. In addition, more attention should be given to the ecological consequences of atmospheric deposition of individual pesticides and of total toxic potencies that regularly exceed environmental criteria for Dutch surface waters and/or toxic threshold values for aquatic organisms.

Hamers, T.; Brink, P.J. van den; Mos, L.; Linden, S.C. van der; Legler, J.; Koeman, J.H.; Murk, A.J

2003-05-01

288

A pesticide monitoring survey in rivers and lakes of northern Greece and its human and ecotoxicological risk assessment.  

Science.gov (United States)

A pesticide monitoring study covering the main rivers and lakes of Northern Greece (Macedonia, Thrace and Thessaly) was undertaken. A total of 416 samples were collected over a 1.5-year sampling period (September 1999- February 2001) from six rivers and ten lakes. The water samples were analyzed with an off-line solid phase extraction technique coupled with a gas chromatography ion trap mass spectrometer using an analytical method for 147 pesticides and their metabolites, including organochlorines, organophosphates, triazines, chloroacetanilides, pyrethroids, carbamates, phthalimides and other pesticides (herbicides, insecticides and fungicides). Based on the pesticide survey results, a human health carcinogenic and non-carcinogenic risk assessment was conducted for adults and children. Ecotoxicological risk assessment was also conducted using default endpoint values and the risk quotient method. Results showed that the herbicides metolachlor, prometryn, alachlor and molinate, were the most frequently detected pesticides (29%, 12.5%, 12.5% and 10%, respectively). They also exhibited the highest concentration values, often exceeding 1?g/L. Chlorpyrifos ethyl was the most frequently detected insecticide (7%). Seasonal variations in measured pesticide concentrations were observed in all rivers and lakes. The highest concentrations were recorded during May-June period, right after pesticide application. Concentrations of six pesticides were above the maximum allowable limit of 0.1?g/L set for drinking water. Alachlor, atrazine and a-HCH showed unacceptable carcinogenic risk estimates (4.5E-06, 4.6E-06 and 1.3E-04, respectively). Annual average concentrations of chlorpyriphos ethyl (0.031?gL), dicofol (0.01?g/L), dieldrin (0.02?g/L) and endosulfan a (0.065?g/L) exceeded the EU environmental quality standards. The risk quotient estimates for the insecticides chorpyrifos ethyl, diazinon and parathion methyl and herbicide prometryn were above acceptable risk values. The coupling of monitoring data to probabilistic human and ecotoxicological risk estimates could find use by Greek regulatory authorities, proposing effective pollution management schemes. PMID:25733189

Papadakis, Emmaluel N; Vryzas, Zisis; Kotopoulou, Athena; Kintzikoglou, Katerina; Makris, Konstantinos C; Papadopoulou-Mourkidou, Euphemia

2015-06-01

289

Estrogenic and esterase-inhibiting potency in rainwater in relation to pesticide concentrations, sampling season and location  

International Nuclear Information System (INIS)

Estrogenic potency of rainwater correlated well with organochlorine concentrations, but could not be attributed to specific pesticides. - In a year-round monitoring program (1998), pesticide composition and toxic potency of the mix of pollutants present in rainwater were measured. The goal of the study was to relate atmospheric deposition of toxic potency and pesticide composition to each other and to sampling period and local agricultural activity. Rainwater was collected in 26 consecutive periods of 14 days in a background location (BACK) and in two locations representative for different agricultural practices, i.e. intensive greenhouse horticulture (HORT) and flower bulb culture (BULB). Samples were chemically analyzed for carbamate (CARB), organophosphate (OP) and organochlorine (OC) pesticides and metabolites. Esterase inhibiting potency of rainwater extracts was measured in a specially developed bio-assay with honeybee esterases and was expressed as an equivalent concentration of the model inhibitor dichlorvos. Estrogenic potency of the extracts was measured in the ER-CALUX reporter gene assay and was expressed as an equivalent concentration of estradiol. Multivariate principal component analysis (PCA) techniques proved to be valuable tools to analyze the numerous pesticide concentrations in relation to toxic potency, sampling location, and sampling season. Pesticide composition in rainwater depended much more on sampling season than on sampling location, but dig season than on sampling location, but differences between SPRING and SUMMER were mainly attributed to local differences in agricultural practice. On average, the esterase inhibiting potency exceeded the maximum permissible concentration set for dichlorvos in The Netherlands, and was significantly higher in HORT than in BACK and BULB. Esterase inhibition correlated significantly with OP and CARB concentrations, as expected given the working mechanism of these insecticides. The estrogenic potency incidentally exceeded NOEC levels reported for aquatic organisms and was highest in SPRING. Although estrogenic potency of rainwater correlated with OC concentrations, the ER-CALUX responses could not be attributed to any particular pesticides. Besides, the contribution of non-analyzed xeno-estrogens as alkylphenol(-ethoxylates) and bisphenol-A to the estrogenic potency of rainwater could not be excluded. Further research should focus on the chemical identification of estrogenic compounds in rainwater. In addition, more attention should be given to the ecological consequences of atmospheric deposition of individual pesticides and of total toxic potencies that regularly exceed environmental criteria for Dutch surface waters and/or toxic threshold values for aquatic organisms

290

Determination of a variety of chemical classes of pesticides in surface and ground waters by off-line solid-phase extraction, gas chromatography with electron-capture and nitrogen-phosphorus detection, and high-performance liquid chromatography with post-column derivatization and fluorescence detection.  

Science.gov (United States)

Octadecyl (C18)-bonded porous silica was evaluated for the extraction of triazines, organochlorine, carbamates and acidic pesticides from surface and ground water. Gas chromatography with selected detection methods (electron-capture detection, nitrogen-phosphorus detection, mass spectrometry) and liquid chromatography-post-column derivatization fluorescence detection was employed for the determination of 32 pesticides. Recoveries varied from 52 to 102%. The recoveries of triazines obtained using C18 extraction cartridges and conventional liquid-liquid extraction (LLE) are compared. The limit of detection for seventeen organochlorine compounds was better than 0.003 microgram/l and the limit of detection for other 15 analytes was better than 0.06 microgram/l. The proposed analytical methodology was applied to analyze pesticides in surface and ground-water samples of the Lassithi Plateau, Crete, Greece. PMID:9818392

Vassilakis, I; Tsipi, D; Scoullos, M

1998-10-01

291

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

292

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

293

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

294

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

295

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.

296

Application of pesticide transport model for simulating diazinon runoff in California’s central valley  

Science.gov (United States)

Dormant spray application of pesticides to almond and other stone fruit orchards is the main source of diazinon during the winter in California's central valley. Understanding the pesticide transport and the tradeoffs associated with the various management practices is greatly facilitated by the use of physically-based contaminant transport models. In this study, performance of Joyce's et al. (2008) pesticide transport model was evaluated using experimental data collected from two ground treatments such as resident vegetation and bare soil. The model simulation results obtained in calibration and validation process were analyzed for pesticide concentration and total load. The pesticide transport model accurately predicted the pesticide concentrations and total load in the runoff from bare field and was capable of simulating chemical responses to rainfall-runoff events. In case of resident vegetation, the model results exhibited a larger range of variation than was observed in the bare soil simulations due to increased model parameterization with the addition of foliage and thatch compartments. Furthermore, the model was applied to study the effect of runoff lag time, extent of crop cover, organic content of soil and post-application irrigation on the pesticide peak concentration and total load. Based on the model results, recommendations were suggested to growers prior to implementing certain management decisions to mitigate diazinon transport in the orchard's spray runoff.

Joyce, Brian A.; Wallender, Wesley W.; Mailapalli, Damodhara R.

2010-12-01

297

Applicability of ELISA-based Determination of Pesticides for Groundwater Quality Monitoring  

Science.gov (United States)

The principals and procedures of ELISA (Enzyme-linked Immunosorbent Assay)-based determination of pesticides (Fenitrothion) in environmental samples were reviewed, and the applicability of the ELISA method for groundwater quality monitoring were validated through the experimental tracer tests in soil columns and the field test in Okinoerabu Island. The test results showed that the ELISA method could be useful not only for screening but also for quantitative analysis of pesticides. In the experimental tracer tests in soil columns, the retardation of pesticides leaching compared with conservative tracers were observed. In the field test, the contamination of the pesticide was detected in groundwater samples in Okinoerabu Island, even though the targeted pesticide was considered to be applied to the upland field 4 months ago. In order to investigate the transport and fate of pesticides in groundwater taking into account retardation from the field to groundwater table and the residue in groundwater, continuous observations of pesticides in groundwater are in a strong need, and the ELISA method is applicable to the long-term quality groundwater monitoring.

Tsuchihara, Takeo; Yoshimoto, Shuhei; Ishida, Satoshi; Imaizumi, Masayuki

298

MONITORING OF ORGANOPHOSPHOROUS PESTICIDE RESDUES IN SAMPLES OF BANANA, PAPAYA, AND BELL PEPPER  

Scientific Electronic Library Online (English)

Full Text Available The objective of this study was to monitor 11 organophosphorus pesticides in samples of papaya, bell pepper, and banana, commercialized in the metropolitan area of Vitória (ES, Brazil). The pesticides were determined by an optimized and validated method using high performance liquid chromatography w [...] ith tandem mass spectrometry (HPLC-MS/MS). All three samples exhibited a matrix effect for most of the pesticides, mainly with signal suppression, and therefore the calibration curves were produced in matrices. Linearity revealed coefficients of determination (r2) greater than 0.9895 for all pesticides and recovery results ranged from between 76% and 118% with standard deviation no greater than 16%. Precision showed relative standard deviation values lower than 19% and HorRat values lower than 0.7, considering all pesticides. Limits of quantification were less than 0.01 mg/kg for all pesticides. Regarding analysis of the samples (50 of each), none of the pesticides exceeded the maximum residue limit determined by Brazilian legislation.

Mariana F., Lemos; Mayara F., Lemos; Henrique P., Pacheco; Rodrigo, Scherer.

2015-02-01

299

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

300

PESTIS: Pesticide Action Network North America  

Science.gov (United States)

As the word Action in its title indicates, PESTIS is definitely an advocacy group and is not moderate on its feelings about pesticides. In fact, a part of PESTIS, is PANNA (Pesticide Action Network North America), which "works to replace pesticide use with ecologically sound and socially just alternatives." Regardless of your feeling towards pesticides, this Web site includes all sorts of data and information related to pesticide use, including ecotoxicological studies on fish, amphibians, fungi, and more, to ideas for alternatives to pesticides. And, for those visitors interested in furthering their own activism, there is a link to current PESTIS projects and campaigns and ways to help.

301

Insights into chromatographic enantiomeric separation of allenes on cellulose carbamate stationary phase.  

Science.gov (United States)

Allenes are cumulenes with three contiguous carbons linked together through double bonds. 1,3-disubstituted allenes are not superimposable on their mirror image; as a consequence they are chiral. Chiral allenes are increasingly important in organic synthesis due to their interesting reactivity. Because of their applications in the field of asymmetric catalysis and in the pharmaceutical industry their optical purity is always a parameter which needs to be determined. In this article, we report the enantiomeric separation of hexa-3,4-diene-3-ylbenzene, an aromatic allene, on a cellulose carbamate (Chiralcel OD-3) stationary phase, using heptane as the mobile phase. Spectroscopic studies using infrared (IR) and vibrational circular dichroism revealed that, in the presence of heptane, the stationary phase undergoes a conformational change due to intermolecular H-bonding between the CO and NH of the neighboring polymer chains. Van't Hoff plots for the retention factor, k, showed that the retention of the two enantiomers is dominated by the enthalpy, while the plot for the selectivity, ?, is entropy driven. This suggests that the enantioselectivity is a result of inclusion of the enantiomers in the cavities of the chrial stationary phase. VCD spectra, along with density functional theory calculation (DFT) of the interaction between each enantiomer and the chiral stationary phase, supported the chromatographic elution order findings. PMID:25193169

Ma, Shengli; Tsui, Hung-Wei; Spinelli, Earl; Bussaca, Carl A; Franses, Elias I; Wang, Nien-Hwa Linda; Wu, Ling; Lee, Heewon; Senanayake, Chris; Yee, Nathan; Gonella, Nina; Fandrick, Keith; Grinberg, Nelu

2014-10-01

302

Unidirectional cross-tolerance between the carbamate insecticide propoxur and the organophosphate disulfoton in mice.  

Science.gov (United States)

Previous studies have shown that subchronic treatment of mice with the organophosphate insecticide, disulfoton, or the carbamate insecticide, propoxur, leads to the development of tolerance to their toxicity. Tolerance to disulfoton was due to a decrease in the number of muscarinic cholinergic receptors, while tolerance to propoxur appeared to be due to an induction of hepatic microsomal enzymes. In the present study we investigated if cross-tolerance between disulfoton and propoxur would occur. Cross-tolerance was evaluated by measuring acute toxicities, cholinesterase and carboxylesterase inhibition and hypothermic and antinociceptive effects. Mice tolerant to propoxur were cross-tolerant to the hypothermic and anticholinesterase effects of disulfoton. Similarly, when mice were pretreated with the microsomal enzyme inducer, phenobarbital, the toxicity of disulfoton was decreased. Mice made tolerant to disulfoton were cross-tolerant to the organophosphate chlorpyrifos, but were more sensitive than controls to the toxicity of propoxur. The acute toxicity of the organophosphate malathion was also increased in disulfoton-tolerant mice. Propoxur is metabolized by mixed function oxidases and possibly by a carboxylesterase. While hepatic microsomal enzymes appeared to be unchanged in disulfoton-tolerant mice, brain and liver carboxylesterase activities were significantly inhibited. Pretreatment of mice with the specific carboxylesterase inhibitor triorthotolylphosphate is known to greatly potentiate the toxicity of malathion and also potentiated, to a lesser extent, the toxicity of propoxur.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:6642106

Costa, L G; Murphy, S D

1983-01-01

303

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 pesticides were ?20 ng/g. The analytical results of the proposed method were in good agreement with proficiency test results (FAPAS, 19116). The recoveries and repeatabilities were in accordance with the criteria set by SANCO Guideline. The validated method was suitable for the analysis of pesticides in tea. PMID:23534490

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

2013-05-01

304

Oxidative Stress Induced by Different Pesticides in the Land Snails, Helix aspersa  

Directory of Open Access Journals (Sweden)

Full Text Available The present study was designated to compare the ability of the two carbamate compounds methomyl and carbofuran, the organophosphorus compound chlorpyrifos and the bipyridylium compound paraquat to induce the oxidative stress and affect some biochemical targets in the terrestrial snail, Helix aspersa. LD50 values for these pesticides were determined 48 h following topical application. They were 240, 500, 900 and 920 ?g/snail for methomyl, carbofuran, chlorpyrifos and paraquat, respectively. Some biomarkers of the oxidative stress such as Lipid Peroxidation (LP, Lactic Dehydrogenase (LDH and Glutathione (GSH as well as the inhibitory effects of these compounds against acetylcholinesterase (AChE were carried out following topical application of 1/4LD50 values. The results showed that carbofuran was the most potent to inhibit AChE in snails followed by methomyl, where the enzyme activities dropped to 9.86 and 28.82% of the control activity, respectively, 48 h following application. Non-significant increase in the levels of thiobarbituric acid-reactive species in the snail tissue homogenate intoxicated with methomyl, paraquat or carbofuran were found comparing to control value, while it was similar to control following chlorpyrifos treatment. On the other hand, the activities of LDH were increased following all tested pesticides. Also, the results showed that GSH level in the snail tissue homogenate was elevated following both methomyl and chlorpyrifos, while it decreased following either carbofuran or paraquat application. It could be concluded that methomyl was the most toxic pesticide followed by carbofuran against the land snail and their mode of action could be due to the induction of oxidative stress in addition to their anticholinesterase potencies. Chlorpyrifos or paraquat had slightly effects to alter the biomarkers of oxidative stress in the snail.

Ahmed K. Salama

2005-01-01

305

Prediction of pesticides chromatographic lipophilicity from the computational molecular descriptors.  

Science.gov (United States)

Quantitative structure-property relationship models were developed for the prediction of pesticides and some PAH compounds lipophilicity based on a wide set of computational molecular descriptors and a set of experimental chromatographic data. The chromatographic lipophilicity of pesticides has been evaluated by high-performance liquid chromatography (HPLC) using different chemically bonded (C18, C8, CN and Phenyl HPLC columns) stationary phases and two different organic modifiers (methanol and acetonitrile, respectively) in the mobile phase composition. Through a systematic study, by using the classic multivariate analysis, several quantitative structure-property/lipophilicity multi-dimensional models were established. Multiple linear regression and genetic algorithm for the variable subset selection were used. The internal and external statistical evaluation procedures revealed some appropriate models for the chromatographic lipophilicity prediction of pesticides. Moreover, the statistical parameters of regression and those obtained by applying t-test for the intercept (a(0)) and for the slope (a(1)) in order to evaluate relationship between experimental and predicted octanol-water partition coefficients in case of the test set compounds, revealed two statistically valid models that can be successfully used in lipophilicity prediction of pesticides. PMID:21268246

Casoni, Dorina; Petre, Jana; David, Victor; Sârbu, Costel

2011-02-01

306

Pesticide risks around the home (image)  

Science.gov (United States)

Pesticides are substances which kill or deter unwanted pests, such as insects or rodents. These substances can ... avoid an accidental ingestion is to keep all pesticides out of the reach of children.

307

Effects of fertilizer and pesticide use  

Science.gov (United States)

When used properly, fertilizer and pesticide application can help protect crops and encourage their growth. However, fertilizers and pesticides can run off into bodies of water and contaminate water sources.

Olivia Worland (Purdue University; Biological Sciences)

2008-06-25

308

78 FR 13264 - Acetochlor; Pesticide Tolerances  

Science.gov (United States)

...the dietary exposure analysis and risk assessment...water models used in pesticide exposure assessment...Acetochlor parent residue exposure is generally...concentrations using the PRZM (Pesticide Root Zone Model) and EXAMS (Exposure Analysis Modeling...

2013-02-27

309

75 FR 29441 - Novaluron; Pesticide Tolerances  

Science.gov (United States)

...the dietary exposure analysis and risk assessment...water models used in pesticide exposure assessment...were used to assess residues of concern in drinking water: The Pesticide Root Zone Model/Exposure Analysis Modeling...

2010-05-26

310

75 FR 51045 - Pesticide Products; Registration Applications  

Science.gov (United States)

...register new uses for pesticide products containing currently registered...docket that addresses multiple products, please indicate to which...follows to register pesticide products containing currently registered...avocado, cacao, citrus, coffee, guava, mango, olive,...

2010-08-18

311

Effects of Urbanization on Water Quality: Pesticides  

Science.gov (United States)

... A Teachers Contact Back to previous page The effects of urbanization on water quality: Pesticides Pesticides are ... in the United States home page. Related topics: Effects of urbanization Ground-water quality Accessibility FOIA Privacy ...

312

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 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.

2013-04-01

313

Pesticide Alternatives Laboratory  

Science.gov (United States)

The Pesticide Alternatives Laboratory of Michigan State University is on the cutting edge of pest control in the Upper Midwest, whether on agricultural or non-agricultural lands, public or private. Visitors interested in seeing the pesky adversaries of the lab, should click on "Bugs of The Lab", on the left hand side of the page, then click on the subcategory "Research Subjects". Along with photos of a dozen pests, including the "Plum Curculio", "Mites", and the "Oblique-Banded Leaf Roller", visitors can read a description of the pest, learn about and see images of the damage they do to specific crops, and discover where they are found on the plant. The Resistant Pest management Newsletter section on the left-hand side of the page has numerous subsections that should be of interest to visitors. Visitors can "Subscribe to the Newsletter" and peruse "Archives of Past Issues". Also interesting is the "Ask an Expert About Resistance Issues" section, which lists ten regions of the earth, and when one of the regions is clicked on, several experts' names pop up with their area of expertise, e-mail, and location. Additionally, anyone who is an expert and qualified, but is not on the list, may have their name added after filling out the "Expert Application", available on the "Ask an Expert..." homepage. All of the experts are volunteers.

314

Pesticide runoff from greenhouse production.  

Science.gov (United States)

A research has been undertaken studying pesticide residues in water from greenhouses and the use of soils and filter materials to reduce such losses. The pesticides detected in water samples collected downstream greenhouses include 9 fungicides, 5 herbicides and 4 insecticides. 10 compounds from flower and vegetable productions were frequently found to exceed environmental risk levels, and with a few exceptions the compounds were found in higher concentrations than those typically found in agricultural runoff. Some compounds were found in high concentrations (>1 microg/l) in undiluted runoff from greenhouses producing vegetables. Nutrient concentrations in the runoff were also sporadically very high, with phosphorous values varying between 0.85 and 7.4 mg P/l, and nitrogen values between 7.5 and 41.4 mg N/l. Undiluted runoff from the productions showed values of 60 mg P/l and 300 mg N/l. High values of pesticides correlated with high values of nutrients, especially P. Column experiments using a sandy agricultural soil and stock solutions of non-polar and slightly polar pesticides mixed with a complex binder and nutrients showed a significant reduction for nearly all of the compounds used, indicating that transport through soil will reduce the concentrations of the studied pesticides. The pesticide adsorption capacity of the filter materials pine bark, peat, Sphagnum moss, compost, oat straw, ferrous sand and clay soil were tested in batch and column experiments. Adsorption were studied contacting the filter materials with aqueous solutions containing greenhouse production pesticides. The batch experiments showed that pine bark and peat, both combining a high content of organic matter with a low ph, provided the highest adsorption for most of the tested pesticides. Sphagnum moss, compost and oat straw also showed high adsorption for most of the pesticides, while the mineral filters provided the lowest adsorption (30-55%). Further column experiments confirmed these results, displaying the best removal efficiency in the organic materials, varying from 200 microg/g in compost, to 500 microg/g in moss, straw and pine bark. PMID:20351415

Roseth, Roger; Haarstad, Ketil

2010-01-01

315

Gas Chromatographic Methodology for the Determination of Some Halogenated Pesticides  

Directory of Open Access Journals (Sweden)

Full Text Available A Gas Chromatography (GC methodology has been validated for the determination of some halogenated pesticides. Complete separation of the pesticide prepared in ethyl acetate was achieved on Rtx - 1 column with dimension, 30m x 0.25mm x 0.25:m. The GC equipped with electron capture detector was run using column temperature programmed from 80ºC (2 min to 200ºC (15 min at the rate of 4ºC/min giving a total analysis time of 47 min. The detector and injector were respectively at temperatures of 300 and 225ºC. The method was validated with respect to precision in terms of reproducibility of retention times and peak heights, linearity and minimum detectable quantity of the pesticides. Under the operated GC conditions, diuron eluted first while heptachlor epoxide was the last to elute. The chromatographic detector was more sensitive to "-endosulfan and $-endosulfan with Minimum Detectable Quantity (MDQ of 0.002 ng. The detector was however, less sensitive to captan with MDQ of 0.08 ng. Margins of errors associated with the precision of the method in terms of reproducibility of retention times yielded standard deviation in the range of 0.026-0.063.

Samuel Afful

2010-09-01

316

77 FR 42433 - Difenoconazole; Pesticide Tolerances  

Science.gov (United States)

...food-use pesticide, if a toxicological...CSFII). As to residue levels in food...unrefined acute analysis for food and...of pesticide residues in food and...actual levels of pesticide residues that have been...dietary exposure analysis and risk...

2012-07-19

317

Multiple headspace solid-phase microextraction after matrix modification for avoiding matrix effect in the determination of ethyl carbamate in bread.  

Science.gov (United States)

This study presents the potential of multiple headspace solid-phase microextraction (multiple HS-SPME) for the quantification of analytes in solid samples. Multiple HS-SPME shares the same advantages as SPME. It also enables a complete recovery of the target compound and therefore the matrix effect, which commonly appears in SPME-based analysis, is avoided. A method based on multiple HS-SPME for the determination of the toxic contaminant ethyl carbamate (EC) in bread samples has been developed and validated, using gas chromatography with flame ionization detector. A novel polyethylene glycol/hydroxy-terminated silicone oil fiber was prepared for the first time and subsequently used instead of commercial ones because of its high extraction ability and good operational stability. An important problem still remained in multiple HS-SPME of EC in fresh bread samples. The adsorption of EC by water in the samples caused low transport of analyte to the headspace, which made multiple HS-SPME invalidated. Mixing with anhydrous sodium sulphate, the sensitivity of the method was improved and the problem was solved. The proposed method showed satisfactory linearity (0.15-1500 ?g g(-1)), precision (1.6%, n=5) and limit of detection (0.041 ?g g(-1)). Good recoveries, from 92.5 to 103.4%, were observed at three spiking levels. The method was applied to 14 bread samples. The multiple HS-SPME technique offers several advantages including reducing the manipulation time and cost, and avoiding analyte losses, especially in the analysis of a large number of samples in different matrices. PMID:22123114

Ye, Chang-Wen; Zhang, Xue-Na; Gao, Yuan-Li; Wang, Yu-Long; Pan, Si-Yi; Li, Xiu-Juan

2012-01-13

318

Determination of amino acid contents of manketti seeds (Schinziophyton rautanenii) by pre-column derivatisation with 6-aminoquinolyl-N-hydroxysuccinimidyl carbamate and RP-HPLC.  

Science.gov (United States)

Defatted kernel flour from manketti seed kernels (Schinziophyton rautanenii) is an underutilised natural product. The plant grows in the wild, on sandy soils little used for agriculture in Southern Africa. The kernels are rich in protein and have a great potential for improving nutrition. The protein content and amino acid profile of manketti seed kernel were studied, using a new analytical method, in order to evaluate the nutritional value. The crude protein content of the press cake and defatted kernel flour was 29.0% and 67.5%, respectively. Leucine and arginine were found to be the most abundant essential and non-essential amino acids, respectively. The seed kernel contained 4.77 g leucine and 12.34 g arginine/100 g of defatted seed kernel flour. Methionine and proline were the least abundant essential and non-essential amino acids to with 0.23 g methionine and 0.36 g proline/100 g of defatted seed kernel flour, respectively. Validation of the pre-column derivatisation procedure with 6-aminoquinolyl-N-hydroxysuccinimidyl carbamate (AQC) for the determination of amino acids was carried out. The analytical parameters were determined: linearity (0.0025-0.20 mM), accuracy of the derivatisation procedure: 86.7-109.8%, precision (method: 0.72-5.04%, instrumental: 0.14-1.88% and derivatisation: 0.15-2.94% and 0.41-4.32% for intraday and interday, respectively). Limits of detection and quantification were 6.80-157 mg/100 g and 22.7-523 mg/100 g kernel flour, respectively. PMID:23870943

Gwatidzo, Luke; Botha, Ben M; McCrindle, Rob I

2013-12-01

319

Modeling pesticide losses from diffuse sources in Germany.  

Science.gov (United States)

A GIS-based model estimates the losses from diffuse sources in surface waters in Germany for 42 active ingredients applied to 11 field crops, vineyards and orchards. For the following pathways of entry: tile drainage, runoff and spray drift, the calculated mean pesticide input amounts to 1490 kg/year, 9060 kg/year and 3350 kg/year, respectively, in 1994. The model results are highly sensitive to the model parameters, primarily the chemical properties of the active ingredients. The modeled water inputs were compared with measured pesticide loads in smaller catchments and large river basins to validate model results. Both datasets agree as to the order of magnitude, nevertheless due to the scale of the study the results should be addressed mainly to comparative interpretations with the focus on the proportions between different active ingredients, soil regions, climates and application periods. PMID:11724487

Bach, M; Huber, A; Frede, H G

2001-01-01

320

Determination of organophosphorus pesticide residues in tomatoes by gas chromatography  

International Nuclear Information System (INIS)

Chloropyriphos and malathion are two organophosphorus pesticides from many others pesticides widely used by famers in agriculture .Because of their bad effect on human health, officials standards are set by the international organisations and communities to ensure safer food for consumer .In the same way, scientists over the world are working hard to develop new detection techniques responding to the international requirements. In this study, an ' IAEA-ethylacetate method ', an adaptation of the popular QuEChERS multi residue method, was optimized to analyse chloropyriphos and Malathion residues in tomatoes .Ethyl-Acetate was used as an extraction solvent the PSA was kept for the clean up procedure. GC-NPD is used for samples analysis .The method optimized is specifique, selective with a recovery averaged more than 70 pour cent. A complete validation of the method is necessary to be used for routine analysis.

321

Lead optimization studies towards the discovery of novel carbamates as potent AChE inhibitors for the potential treatment of Alzheimer's disease.  

Science.gov (United States)

The optimization of our previous lead compound 1 (AChE IC(50)=3.31 ?M) through synthesis and pharmacology of a series of novel carbamates is reported. The synthesized compounds were evaluated against mouse brain AChE enzyme using the colorimetric method described by Ellman et al. The three compounds 6a (IC(50)=2.57?M), 6b (IC(50)=0.70 ?M) and 6i (IC(50)=2.56 ?M) exhibited potent in vitro AChE inhibitory activities comparable to the drug rivastigmine (IC(50)=1.11 ?M). Among them, the compound 6b has been selected as possible optimized lead for further neuropharmacological studies. In addition, the AChE-carbamate Michaelis complexes of these potent compounds including rivastigmine and ganstigmine have been modeled using covalent docking protocol of GOLD and important direct/indirect interactions contributing to stabilization of the AChE-carbamate Michaelis complexes have been investigated. PMID:23026084

Roy, Kuldeep K; Tota, Santoshkumar; Tripathi, Tusha; Chander, Subhash; Nath, Chandishwar; Saxena, Anil K

2012-11-01

322

Maternal pesticide exposure from multiple sources and selected congenital anomalies.  

Science.gov (United States)

We explored the relation between various potential sources of maternal periconceptional pregnancy exposures to pesticides and congenital anomalies in offspring. Data were derived from a case-control study of fetuses and liveborn infants with orofacial clefts, neural tube defects, conotruncal defects, or limb anomalies, among 1987-1989 California births and fetal deaths. We conducted telephone interviews with mothers of 662 (85% of eligible) orofacial cleft cases, 265 (84%) neural tube defect cases, 207 (87%) conotruncal defect cases, 165 (84%) limb cases, and 734 (78%) nonmalformed controls. The odds ratio (OR) estimates did not indicate increased risk for any of the studied anomaly groups among women whose self-reported occupational tasks were considered by an industrial hygienist likely to involve pesticide exposures. Paternal occupational exposure to pesticides, as reported by the mother, revealed elevated ORs for only two of the cleft phenotypes [OR = 1.7 [95% confidence interval (CI) = 0.9-3.4] for multiple cleft lip with/without cleft palate and OR = 1.6 [95% CI = 0.7-3.4] for multiple cleft palate]. Use of pesticide products for household gardening, by mothers or by professional applicators, was associated with ORs > or =1.5 for most of the studied anomalies. Use of pesticide products for the control of pests in or around homes was not associated with elevated risks for most of the studied anomalies, although women who reported that a professional applied pesticides to their homes had increased risks for neural tube defect-affected pregnancies [OR = 1.6 (95% CI = 1.1-2.5)] and limb anomalies [OR = 1.6 (95% CI = 1.0-2.7)]. Having a pet cat or dog and treating its fleas was not associated with increased anomaly risk. Women who reported living within 0.25 miles of an agricultural crop revealed increased risks for offspring with neural tube defects [OR = 1.5 (95%CI = 1.1-2.1)]. For many of the comparisons, data were sparse, resulting in imprecise effect estimation. Despite our investigating multiple sources of potential pesticide exposures, without more specific information on chemical and level of exposure, we could not adequately discriminate whether the observed effects are valid, whether biased exposure reporting contributed to the observed elevated risks, or whether nonspecific measurement of exposure was responsible for many of the observed estimated risks not being elevated. PMID:9888281

Shaw, G M; Wasserman, C R; O'Malley, C D; Nelson, V; Jackson, R J

1999-01-01

323

Managing insecticide resistance in malaria vectors by combining carbamate-treated plastic wall sheeting and pyrethroid-treated bed nets  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Pyrethroid resistance is now widespread in Anopheles gambiae, the major vector for malaria in sub-Saharan Africa. This resistance may compromise malaria vector control strategies that are currently in use in endemic areas. In this context, a new tool for management of resistant mosquitoes based on the combination of a pyrethroid-treated bed net and carbamate-treated plastic sheeting was developed. Methods In the laboratory, the insecticidal activity and wash resistance of four carbamate-treated materials: a cotton/polyester blend, a polyvinyl chloride tarpaulin, a cotton/polyester blend covered on one side with polyurethane, and a mesh of polypropylene fibres was tested. These materials were treated with bendiocarb at 100 mg/m2 and 200 mg/m2 with and without a binding resin to find the best combination for field studies. Secondly, experimental hut trials were performed in southern Benin to test the efficacy of the combined use of a pyrethroid-treated bed net and the carbamate-treated material that was the most wash-resistant against wild populations of pyrethroid-resistant An. gambiae and Culex quinquefasciatus. Results Material made of polypropylene mesh (PPW provided the best wash resistance (up to 10 washes, regardless of the insecticide dose, the type of washing, or the presence or absence of the binding resin. The experimental hut trial showed that the combination of carbamate-treated PPW and a pyrethroid-treated bed net was extremely effective in terms of mortality and inhibition of blood feeding of pyrethroid-resistant An. gambiae. This efficacy was found to be proportional to the total surface of the walls. This combination showed a moderate effect against wild populations of Cx. quinquefasciatus, which were strongly resistant to pyrethroid. Conclusion These preliminary results should be confirmed, including evaluation of entomological, parasitological, and clinical parameters. Selective pressure on resistance mechanisms within the vector population, effects on other pest insects, and the acceptability of this management strategy in the community also need to be evaluated.

Pennetier Cédric

2009-10-01

324

EPA (ENVIRONMENTAL PROTECTION AGENCY) METHOD STUDY 30, METHOD 625 - BASE/NEUTRALS, ACIDS AND PESTICIDES  

Science.gov (United States)

The work which is described in this report was performed for the purpose of validating, through an interlaboratory study, Method 625 for the analysis of the base/neutral, acid, and pesticide priority pollutants. This method is based on the extraction and concentration of the vari...

325

Comparison of pesticide leaching potential to groundwater under EU FOCUS and site specific conditions.  

Science.gov (United States)

The EU FOCUS scenarios are a set of nine standard scenarios based on a combination of crop, soil and weather data used throughout Europe to evaluate the leaching potential of pesticides to groundwater. In Ireland, two predefined EU FOCUS scenarios (Okehampton and Hamburg) appear to be the most appropriate to Irish conditions. However, there is concern that these scenarios may not accurately represent Irish specific conditions, especially in terms of soil and climatic weather. Therefore, the objective of this study was to parameterise a number of site specific locations in Ireland (represented by Oakpark, Clonroche, Rathangan and Elton series soils) and to compare simulated leachate levels at these locations to EU FOCUS scenarios using the PELMO (Pesticide Leaching Model) simulation model. The hydrological processes were validated using observed data for soil tension and leachate. The appropriate EU FOCUS scenarios were then simulated for the given locations and compared to the parameterised scenario. All scenarios were run using the same version of PELMO, therefore eliminating any software impacts. The models were run for 26 years using appropriate meteorological data. The results showed significant difference between the parameterised model pesticide leaching and that resulting from the EU FOCUS scenarios, the latter overestimating site pesticide leaching from 42 to 99%. The results indicated a significant conservatism in using EU FOCUS scenarios to determine potential pesticide concentration in the leachate under Irish specific conditions and ensure the desired level of protection against pesticide contamination of national water resources. PMID:23831789

Labite, Herve; Holden, Nicholas M; Richards, Karl G; Kramers, Gaelene; Premrov, Alina; Coxon, Catherine E; Cummins, Enda

2013-10-01

326

Multiresidue Analysis of Pesticides in Soil by Liquid-Solid Extraction Procedure  

Directory of Open Access Journals (Sweden)

Full Text Available A multiresidue method for simultaneous determination of four pesticides (diazinon,acetochlor, aldrine and carbofuran belonging to different pesticide groups, extractedfrom soil samples, is described. The method presented is based on liquid-solid extraction(LSE and determination of pesticides, i.e. the pesticides were extracted by methanol-acetone mixture, purified on florisil column and eluted by ethyl acetate-acetone mixture.Optimization of the main parameters affecting the LSE procedure, such as the choiceof purification sorbent, as well as the elution solvent and its volume, were investigated indetails and optimized. Also, validation of the proposed method was done.Gas chromatography-mass spectrometry (GC-MS was used for detection and quantificationof the pesticides studied. Relative standard deviation (RSD and recovery values formultiple analysis of soil samples fortified with 30 ?g/kg of each pesticide were below 8%and higher than 89%, respectively. Limits of detection (LOD for all the compounds studiedwere less than 4 ?g/kg.

Rada ?urovi?

2012-01-01

327

Impact of chemical- and bio-pesticides on bacterial diversity in rhizosphere of Vigna radiata.  

Science.gov (United States)

To study the effects of two chemical pesticides (chlorpyrifos and endosulfan), and a bio-pesticide (azadirachtin) on bacterial diversity in rhizospheric soil, a randomized pot experiment was conducted on mung bean (Vigna radiata) with recommended and higher doses of pesticides. Denaturing gradient gel electrophoresis was used to analyze such effects on both resident and active bacterial communities across two time points. It was observed that higher doses of azadirachtin mimicked the effects of chlorpyrifos on bacterial diversity. Both azadirachtin and chlorpyrifos showed a dose- and time-dependent effect, which was observable only at the RNA level. Endosulfan treatments showed dissimilar profiles compared to control. Most of the bands showed high sequence similarities to known bacterial groups, including many nitrogen-fixing, phosphate-solubilizing, and plant-growth-promoting bacteria. This study indicates that pesticides display non-target effects on active microbial populations that serve important ecosystem functions, thereby emphasizing the need to critically investigate and validate the use of bio-pesticides in agriculture before accepting them as safe alternatives to chemical pesticides. PMID:24085606

Gupta, Sukriti; Gupta, Rashi; Sharma, Shilpi

2013-12-01

328

Collembola and macroarthropod community responses to carbamate, organophosphate and synthetic pyrethroid insecticides: Direct and indirect effects  

Energy Technology Data Exchange (ETDEWEB)

Non-target effects on terrestrial arthropod communities of the broad-spectrum insecticides chlorpyrifos and cypermethrin and the selective insecticide pirimicarb were investigated in winter wheat fields in summer. Effects of chlorpyrifos on arthropod abundance and taxonomic richness were consistently negative whereas effects of cypermethrin were negative for predatory arthropods but positive for soil surface Collembola. Pirimicarb effects were marginal, primarily on aphids and their antagonists, with no effect on the Collembola community. Collembola-predator ratios were significantly higher following cypermethrin treatment, suggesting that cypermethrin-induced increases in collembolan abundance represent a classical resurgence. Observations in other studies suggest Collembola resurgences may be typical after synthetic pyrethroid applications. Collembola responses to insecticides differed among species, both in terms of effect magnitude and persistence, suggesting that coarse taxonomic monitoring would not adequately detect pesticide risks. These findings have implications for pesticide risk assessments and for the selection of indicator species. - Direct and indirect insecticide effects differ among closely-related arthropod taxa; resurgence of Collembola may occur widely after synthetic pyrethroid insecticide applications.

Frampton, Geoff K. [Ecology and Evolutionary Biology Group, School of Biological Sciences, University of Southampton, Bassett Crescent East, Southampton SO16 7PX (United Kingdom)]. E-mail: gkf@soton.ac.uk; Brink, Paul J. van den [Alterra, Wageningen University and Research Centre, P.O. Box 47, 6700 AA Wageningen (Netherlands); Wageningen University, Department of Aquatic Ecology and Water Quality Management, Wageningen University and Research Centre, P.O. Box 8080, 6700 DD Wageningen (Netherlands)

2007-05-15

329

In vitro screening of 200 pesticides for agonistic activity via mouse peroxisome proliferator-activated receptor (PPAR)? and PPAR? and quantitative analysis of in vivo induction pathway  

International Nuclear Information System (INIS)

Peroxisome proliferator-activated receptors (PPARs) are ligand-dependent transcription factors and key regulators of lipid metabolism and cell differentiation. However, there have been few studies reporting on a variety of environmental chemicals, which may interact with these receptors. In the present study, we characterized mouse PPAR? and PPAR? agonistic activities of 200 pesticides (29 organochlorines, 11 diphenyl ethers, 56 organophosphorus pesticides, 12 pyrethroids, 22 carbamates, 11 acid amides, 7 triazines, 8 ureas and 44 others) by in vitro reporter gene assays using CV-1 monkey kidney cells. Three of the 200 pesticides, diclofop-methyl, pyrethrins and imazalil, which have different chemical structures, showed PPAR?-mediated transcriptional activities in a dose-dependent manner. On the other hand, none of the 200 pesticides showed PPAR? agonistic activity at concentrations ? 10-5 M. To investigate the in vivo effects of diclofop-methyl, pyrethrins and imazalil, we examined the gene expression of PPAR?-inducible cytochrome P450 4As (CYP4As) in the liver of female mice intraperitoneally injected with these compounds (? 300 mg/kg). RT-PCR revealed significantly high induction levels of CYP4A10 and CYP4A14 mRNAs in diclofop-methyl- and pyrethrins-treated mice, whereas imazalil induced almost no gene expressions of CYP4As. In particular, diclofop-methyl induced as high levels of CYP4A mRNAs as WY-14643, a potent PPAR? agonist. Thus, most of tt PPAR? agonist. Thus, most of the 200 pesticides tested do not activate PPAR? or PPAR? in in vitro assays, but only diclofop-methyl and pyrethrins induce PPAR? agonistic activity in vivo as well as in vitro

330

Ultra performance liquid chromatography atmospheric pressure photoionization high resolution mass spectrometric method for determination of multiclass pesticide residues in grape and mango juices.  

Science.gov (United States)

A novel analytical method was developed for determination of organochlorine, synthetic pyrethroid, organophosphate and carbamate pesticide residues in fruit juices using ultra performance liquid chromatography-atmospheric pressure photoionization-high resolution mass spectrometry (UPLC-APPI-HRMS). The analytes were extracted from fruit juices by dispersive solid-phase extraction using multi-walled carbon nanotubes (MWCNTs). The analysis was carried out in full scan mode using dual ionization mode of APPI in the mass range of 100-650 units. The limit of detection and limit of quantification values for the pesticides were in the range of 0.025-0.15 ng mL(-1) and 0.1-0.5 ng mL(-1) respectively. The matrix effect of the method was found to be low and extraction recoveries were in the range of 60-110%. Some of the real fruits juice samples showed the presence of some pesticides in the range of 6.5-24.8 ng L(-1). PMID:25466136

Deme, Pragney; Upadhyayula, Vijayasarathi V R

2015-04-15

331

Pesticide residue profile and nutrient characteristics of the Densu River Basin in Ghana  

International Nuclear Information System (INIS)

The Densu River Basin is one of the largest agricultural areas in Ghana. About 80% of people living in this area rely on agricultural activities for subsistence. The practice of using pesticides such as organochlorines, organophosphates, carbamates, pyrethroids and several others in agriculture and public health programs have raised concerns about potentially adverse effects on human health and the environment. Assessment of human health implications of non-point sources within a river basin include pesticide residues analysis of water, sediment and fish and monitoring of physico-chemical parameters in waters that serve as source of drinking water for the entire community within the basin. In this study, a field survey was conducted to assess farmers' knowledge of safe handling and use of pesticides. Nutrient chemistry and surface water characteristics of the Densu River and its tributaries, type and levels of pesticide residues and their trends in water, sediment and fish in the basin were also evaluated. The study also assessed the health risk associated with pesticide contamination of fish from the Basin as well as the relationship between land use and groundwater contamination. Generally surface and ground water bodies in the Densu River basin were found to be polluted with respect to nutrients and pesticides. Waters from the basin were found to be fresh, slightly acidic, and weakly mineralized with low chemical constituents. Nitrate (NO3-N) levels in sts. Nitrate (NO3-N) levels in surface water ranged between 0.12 - 31.07 mgL-1 while ammonia was between 0.01 - 2.10 mgL-1 and that of phosphate was 0.012 - 2.45 mgL-1. Pesticide residues and metabolites detected in water, sediment and fish samples from the Densu River Basin were organochlorines. In an average 96% of fish samples, 13.69% of sediment and 3.30% of water samples, at least one pesticide residue was detected per sample. Of the numerous pesticides evaluated, ? -HCH, DDT, aldrin, dieldrin, DDE, endosulfan sulphate, ?-chlordane, endrin and ?-HCH were detected in fish, water and sediment samples. Aldrin and dieldrin levels detected were above the recommended limit of 0.03 ?L-1 with endosulfan, endrin and chlordane registering levels above their recommended limits of 20.0?L-1 and 0.2 ?L-1 respectively for drinking water. Pesticide residues in fish samples varied between 0.10 ?gKg-1 to 30.90 ?gKg-1. The highest level was detected in Hepsetus odoe (HO-N). Contamination pattern of pesticide residues in fish samples was generally in the order of p'p'-DDE > heptachlor > ?- HCH > p'p'-DDT > endosulfan Sulphate > ?-endosulfan > ?- HCH > ?-chlordane > dieldrin > endrin ketone > methoxychlor > endrin > aldrin > endrin aldehyde. Data obtained from the field survey regarding safe use of pesticides, toxicity awareness and symptoms among farmers indicated that a very high proportion of farmers were at high risk of pesticide poisoning from occupational exposure. More than 90% of farm workers did not practice safety precaution during pesticide formulation and application leading to considerable prevalence of pesticide related illness in this agricultural community. The presence of pesticide residues in fish was of further concern because fish is the main protein diet for humans in the basin. 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 registered were lower than the reference doses. 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. In children, between the ages of 0 - 1year, the hazard indices of 2.64, 1.720, 1.736 and 0.792 were computed for ?-endosulfan, heptachlor, endosulfan sulphate and dieldrin respectively while for children between the ages 1 -11years, hazard indices for heptachlor, ?-endosu

332

Pesticide residues in Nile tilapia (Oreochromis niloticus) and Nile perch (Lates niloticus) from Southern Lake Victoria, Tanzania  

Energy Technology Data Exchange (ETDEWEB)

Nile tilapia (Oreochromis niloticus) and Nile perch (Lates niloticus) samples were collected from fish landing stations in nine riparian districts on the Tanzanian side of Lake Victoria and screened for residues of 64 organochlorine, organophosphorus, carbamate, and pyrethroid pesticides. The residue levels in the fish fillet were up to 0.003, 0.03 and 0.2 mg/kg fresh weight (0.7, 3.8 and 42 mg/kg lipid weight) of fenitrothion, DDT and endosulfan, respectively. Mean levels within sites were up to 0.002, 0.02 and 0.1 mg/kg fresh weight (0.5, 0.5 and 16 mg/kg lipid weight), respectively. The detection of higher levels of p,p'-DDT than the degradation products (p,p'-DDD and p,p'-DDE), and higher levels of endosulfan isomers ({alpha} and {beta}) than the sulphate, in fish samples, implied recent exposure of fish to DDT and endosulfan, respectively. Generally, most of the fish samples had residue levels above the average method detection limits (MDLs), but were within the calculated ADI. - Fish from Lake Victoria had relatively low pesticide levels.

Henry, L. [Chemistry Department, University of Dar es Salaam. PO Box 35061, Dar es Salaam (Tanzania); Kishimba, M.A. [Chemistry Department, University of Dar es Salaam. PO Box 35061, Dar es Salaam (Tanzania)]. E-mail: kishimba@chem.udsm.ac.tz

2006-03-15

333

Pesticide residues in Nile tilapia (Oreochromis niloticus) and Nile perch (Lates niloticus) from Southern Lake Victoria, Tanzania  

International Nuclear Information System (INIS)

Nile tilapia (Oreochromis niloticus) and Nile perch (Lates niloticus) samples were collected from fish landing stations in nine riparian districts on the Tanzanian side of Lake Victoria and screened for residues of 64 organochlorine, organophosphorus, carbamate, and pyrethroid pesticides. The residue levels in the fish fillet were up to 0.003, 0.03 and 0.2 mg/kg fresh weight (0.7, 3.8 and 42 mg/kg lipid weight) of fenitrothion, DDT and endosulfan, respectively. Mean levels within sites were up to 0.002, 0.02 and 0.1 mg/kg fresh weight (0.5, 0.5 and 16 mg/kg lipid weight), respectively. The detection of higher levels of p,p'-DDT than the degradation products (p,p'-DDD and p,p'-DDE), and higher levels of endosulfan isomers (? and ?) than the sulphate, in fish samples, implied recent exposure of fish to DDT and endosulfan, respectively. Generally, most of the fish samples had residue levels above the average method detection limits (MDLs), but were within the calculated ADI. - Fish from Lake Victoria had relatively low pesticide levels

334

Ditches influence on hillslope flow. Consequences on pesticides transfer  

Science.gov (United States)

Man-made objects of landscape as ditches or vegetative strips, which can be found on rural watersheds, constitute hydrologic discontinuities, which may influence flows and pollutant transfer between the fields and the hydrographic network. Particularly, as pesticides may be degraded or be adsorbed during their transfer, both the way they follow and the transfer duration greatly influence their fate. In this context, according to their characteristics, ditches may behave as by-pass for the transport of pesticides, impeding some of the dissipation mechanisms as sorption by soil particles or retention of surface runoff by vegetative strips ; anyway, they may also contribute to pesticide dissipation to a certain extent, by infiltration in their bed or pollutant sorption on their substratum. This article presents a field experiment in order to assess how much pesticide flux a small ditch bordering a field can collect. This work is completed by the study of pesticide retention in such a ditch. Two ditches were equipped on the Arvalis site of "La Jaillière "(western France) : one is perpendicular to the slope, in order to maximise interception of flow coming from upslope, the other is a drainage collector, situated in a little thalweg. For both, equipment consists in piezometry, tensiometry, and discharge measurement. The hillslope where is located the first ditch is also equipped following two transects : the ditch does not influence the first one, whereas the second one is passing through this discontinuity. Moreover, water quality in the groundwater (pesticide concentrations and geochemical environment) is analysed every week or two weeks. Theses analyses aim at validating the hypothesis of ditch and hillslope transfer behaviour that the hydrological survey is leading to. The two first years of hydrological survey confirmed that two groundwater tables are present on the site : the deeper one, situated in the schist, under a layer of less permeable altered schist is present during all the year, while the other one developed itself on this less permeable layer, when water balance is positive. The obtained data and the three-dimensional saturated modelisation that was made (with Visual Modflow 2000) allowed to characterise and to quantify exchanges between the two water tables, considering the position on the hillslope and the period of the year. These results have been put in parallel with the pesticide concentrations measured in the groundwater for different positions on the slope. At the time being, as concerns water quality, only one year was monitored, and concentrations are quite low, even if they confirm the presence of pesticide deep in the regional aquifer. This result must be counterbalanced by the fact that the last pesticide applications on the studied hillslope occurred more than two years ago. Another pesticide application is scheduled at the beginning of 2003, and will be accompanied by a bromure application, in order to improve the comprehension of water flow and pollutants transfer.

Carluer, N.; Adamiade, C. V.; Margoum, C.; Dutertre, A.; Dramais, G.; Barrere, B.; Barrier, R.

2003-04-01

335

ABIOTIC HYDROLYSIS OF SORBED PESTICIDES  

Science.gov (United States)

The hydrolysis of pesticides that are sorbed to sterilized natural sediments has been investigated in aqueous systems at acid, neutral and alkaline pH's. The results show that the rate constants of pH independent ('neutral') hydrolyses are the same within experimental uncertainti...

336

Adsorption of pesticides on resins.  

Science.gov (United States)

The objective of this work was to assess the capability of organic hydrophobic polymeric resins Amberlite XAD-4 and XAD-7 to remove the pesticides alachlor and amitrole from water. The pesticides adsorption on the two different adsorbents was measured by batch equilibrium technique and isotherm types and parameters were estimated. Two theoretical models were applied based on a Freundlich and a Langmuir isotherms. The effect of pesticides chemical composition and structure as well as the nature of solid surface on the efficiency of adsorption was evaluated. The influence of pH also was studied. In low pH solutions adsorption of amitrole was higher upon the nonionic aliphatic acrylic ester copolymer XAD-7 in comparison to the nonionic, crosslinked macroreticular copolymer of styrene divinylbenzene XAD-4. In neutral and intermediate pH solutions the polar acrylic ester copolymer XAD-7 was more effective to the retention of alachlor. The acrylic ester copolymer showed at pH 3 the lower effectiveness in alachlor removal from water. The data of the adsorption isotherms of pesticides upon the examined polymeric resins seemed to conform to both the Freundlich and the Langmuir isotherm models. PMID:12617554

Kyriakopoulos, Grigorios; Hourdakis, Adamadia; Doulia, Danae

2003-03-01

337

Assessing Health Risks from Pesticides  

Science.gov (United States)

... effects (non-cancer) Carcinogenicity (cancer) Developmental and Reproductive Testing: Identify effects in the fetus of an exposed pregnant female (birth defects) and how pesticide exposure affects the ability of a test animal to successfully reproduce. Mutagenicity Testin g : Assess a ...

338

EVALUATION OF 10 PESTICIDE METHODS  

Science.gov (United States)

Ten pesticide analysis methods were evaluated. The compounds listed in each method were analyzed in triplicate at two concentration levels in reagent water and POTW effluent. Each method was performed as written with only minor modifications as approved by the USEPA Project Offic...

339

Pesticide transport with runoff from turf: observations compared with TurfPQ model simulations.  

Science.gov (United States)

Pesticides applied to turf grass have been detected in surface waters raising concerns of their effect on water quality and interest in their source, hydrological transport and use of models to predict transport. TurfPQ, a pesticide runoff model for turf grass, predicts pesticide transport but has not been rigorously validated for larger storms. The objective of this study was to determine TurfPQ's ability to accurately predict the transport of pesticides with runoff following more intense precipitation. The study was conducted with creeping bentgrass [Agrostis palustris Huds.] turf managed as a golf course fairway. A pesticide mixture containing dicamba, 2,4-D, MCPP, flutolanil, and chlorpyrifos was applied to six adjacent 24.4 by 6.1 m plots. Controlled rainfall simulations were conducted using a rainfall simulator designed to deliver water droplets similar to natural rain. Runoff flow rates and volume were measured and water samples were collected for analysis of pesticide concentrations. Six simulations yielded 13 events with which to test TurfPQ. Measured mean percentage of applied pesticide recovered in the runoff for dicamba, 2,4-D, MCPP, flutolanil, and chlorpyrifos was 24.6, 20.7, 14.9, 5.9, and 0.8%, respectively. The predicted mean values produced by TurfPQ were 13.7, 15.6, 15.5, 2.5, and 0.2%, respectively. The model produced correlations of r=0.56 and 0.64 for curve number hydrology and measured hydrology, respectively. Comparisons of the model estimates with our field observations indicate that TurfPQ under predicted pesticide runoff during 69.5+/-11.4 mm, 1.9+/-0.2 h, simulated storms. PMID:19875796

Kramer, Kirsten E; Rice, Pamela J; Horgan, Brian P; Rittenhouse, Jennifer L; King, Kevin W

2009-01-01

340

Determination of multiclass pesticide residues in apple juice by gas chromatography-mass selective detection after extraction by matrix solid-phase dispersion.  

Science.gov (United States)

A multiresidue method is described for the analysis of 106 multiclass pesticides (organochlorine, organophosphate, carbamate, pyrethroid, and triazine classes) in apple juice in a single injection. The determination procedure was based on matrix solid-phase dispersion of juice on diatomaceous earth in a glass column and subsequent extraction with a mixture of hexane-dichloromethane (1 + 1) at a flow rate of 5 mL/min. The analytes were determined by capillary gas chromatography with mass spectrometric detection and confirmed by their retention times and ion ratios. The coefficients of variation for analysis of samples fortified over the range of 0.01-0.2 mg/kg were 1.62 to 18.4%, and the recoveries for all analytes were between 70 and 110%. PMID:15295893

Hu, Xiaozhong; Jianxin, Yu; Zhigang, Yan; Lansun, Ni; Yanfei, Lin; Peng, Wang; Jing, Li; Xin, Huang; Xiaogang, Chu; Yibin, Zhang

2004-01-01

341

Application of a radiometric enzymic method for monitoring organophosphorus and carbamate insecticide residues in water of the Danube River  

International Nuclear Information System (INIS)

Pesticide residue analyses are conventionally based on gas chromatography. These analytic procedures include tedious extraction and clear-up manipulations prior to the actual gas chromatographic determinations. Radioenzymatic method was recently applied in a residue monitoring programme on the Danube River. The programme has demonstrated that the radioenzymatic method has many advantages as a monitoring procedure in aquatic environment. Quick information can be gained without tedious sample clear-up procedure. The anticholinesteratic pesticides and the anticholinesteratic activities can be detected

342

The use and disposal of household pesticides  

International Nuclear Information System (INIS)

Most pesticides are synthetic chemicals manufactured specifically for their toxic properties to the target species, and widely used globally. Several epidemiological studies in the United States have suggested health concerns arising from the chronic exposure of young children to pesticides in the domestic environment. In the UK very little is currently known about how nonoccupational pesticides are being used or disposed of. Any use of pesticides is a potential risk factor for children's exposure, and any potential exposure is likely to be reduced by the parents' adopting precautionary behaviour when using these pesticide products. This was investigated using a sample of 147 parents from the Avon Longitudinal Study of Parents and Children cohort in and around Bristol, through an in-depth interview between August and November 2001. The results of this study add to the understanding of the underlying behaviour of parents applying pesticide products in the home environment in the UK. Pesticides are readily available, and are normally purchased in do-it-yourself shops and supermarkets and mostly disposed of in domestic waste. Safety was stated by 45% of parents to be the most important factor to consider when buying a pesticide. When buying pesticide products, labels were stated to be the most important source of information about pesticides. However, a third of parents stated they would not follow the product label exactly when using a product, just under half felt labeusing a product, just under half felt labels were both inadequate and hard to understand, and about 10% of parents would not take notice of warnings on the pesticide label. Less than half of parents would use gloves when applying a pesticide, although the use of protective equipment such as gloves during the application of pesticides could greatly reduce the exposure. It is a public health concern that the instructions on the labels of products may not always be understood or followed, and further understanding of user behaviour is needed

343

Uso de plaguicidas inhibidores de acetilcolinesterasa en once entidades territoriales de salud en Colombia, 2002-2005 The use of acetylcholinesterase inhibitors pesticides in eleven local health institutions, Colombia, 2002-2005  

Directory of Open Access Journals (Sweden)

Full Text Available Introducción. Por ser los plaguicidas anticolinesterásicos una causa importante de intoxicación y de muerte por intoxicación en los países en vía de desarrollo, el Instituto Nacional de Salud implementó el Programa de Vigilancia Epidemiológica de Organofosforados y Carbamatos, del cual, este informe corresponde al período 2002-2005.
Objetivo. Determinar la actividad de la acetilcolinesterasa en participantes con riesgo de exposición a plaguicidas organofosforados y carbamatos, e identificar los plaguicidas más utilizados en el área estudiada.
Materiales y métodos. Es un estudio descriptivo de información reportada al Programa de Vigilancia Epidemiológica de Organofosforados y Carbamatos por once departamentos colombianos, los cuales realizaron la determinación de acetilcolinesterasa con el equipo Lovibond.
Resultados. Participaron 28.303 personas con riesgo de exposición a plaguicidas; 81,4% eran hombres. El 9,3% de las determinaciones analíticas fueron anormales, con una prevalencia de anormalidad entre los hombres de 9,9% y de 7,0% en las mujeres. Presentaron mayor prevalencia de valores anormales los grupos de edad de 18 a 25 años (12,3% y de 0 a 5 años (10,7%, y los oficios de jornalero (27,0% y servicios generales del campo (26,1%. De los 975 participantes, en el departamento del Meta, 80% de los participantes presentaron niveles anormales de actividad de la enzima. Los plaguicidas más reportados fueron los organofosforados (39,7% y carbamatos (16,6%.
Conclusión. El incremento en la prevalencia de valores anormales de la acetilcolinesterasa y el riesgo de exposición infantil, hacen necesario disminuir el uso y la comercialización de plaguicidas de alto riesgo, y utilizar métodos menos tóxicos para el control de plagas.Introduction. Due to the importance of acetylcholinesterase inhibiting chemicals as pesticides in developing countries, the Instituto Nacional de Salud in Colombia designed the organophosphate and carbamate epidemiological surveillance program for the period 2002-2005.
Objective. The acetylcholinesterase activity was determined in study participants with a history of organophosphate and carbamate exposure and the most commonly used pesticides were identified in each study area.
Materials and methods. The information was compiled from reports sent to the Instituto Nacional de Salud organophosphate and carbamate epidemiological surveillance program from each of 11 provinces in Colombia. The analytical determination of the biomarker was performed by acetylcholinestare activity determined with the Lovibond field equipment.
Results. A total of 28,303 people were designated as having risk of exposure to pesticides. Most were men (81.4%. Abnormal determinations averaged 9.3% (9.9% in men and 7.0% in women. The 18-25 year old age group showed the highest prevalence of abnormal results (12.3%, followed by the group of 0-5 year olds (10.7%. The highest prevalence of abnormal acetylcholinesterase activity was in farm workers (27.0%, followed by general outdoor activities (26.1%. In the province of Meta, 80% of participants showed abnormal values of enzyme activity. The most commonly used pesticides were organophosphates (39.7% and carbamates (16.6%.
Conclusion. The increase in the prevalence of abnormal values of acetylcholinesterase activity and the risk of exposure to pesticides in children necessitates a lowering of use and commercialization of high risk pesticides, and a need for developing safer methods for pest management.

Jaime Eduardo Ortiz

2010-03-01

344

75 FR 13284 - Pesticide Program Dialogue Committee; Request for Nominations to the Pesticide Program Dialogue...  

Science.gov (United States)

...the Agency by law. The following sectors are represented on the current PPDC: Environmental/public interest and animal rights groups; farm worker organizations; pesticide industry and trade associations; pesticide user, grower, and...

2010-03-19

345

77 FR 64990 - Pesticide Program Dialogue Committee; Request for Nominations to the Pesticide Program Dialogue...  

Science.gov (United States)

...and farm worker groups; pesticide users and growers; animal rights groups; pest consultants; State, local, and tribal...the current PPDC: Environmental/public interest and animal rights groups; farm worker organizations; pesticide...

2012-10-24

346

Pesticide Environmental Accounting: a method for assessing the external costs of individual pesticide applications.  

Science.gov (United States)

The Pesticide Environmental Accounting (PEA) tool provides a monetary estimate of environmental and health impacts per hectare-application for any pesticide. The model combines the Environmental Impact Quotient method and a methodology for absolute estimates of external pesticide costs in UK, USA and Germany. For many countries resources are not available for intensive assessments of external pesticide costs. The model converts external costs of a pesticide in the UK, USA and Germany to Mediterranean countries. Economic and policy applications include estimating impacts of pesticide reduction policies or benefits from technologies replacing pesticides, such as sterile insect technique. The system integrates disparate data and approaches into a single logical method. The assumptions in the system provide transparency and consistency but at the cost of some specificity and precision, a reasonable trade-off for a method that provides both comparative estimates of pesticide impacts and area-based assessments of absolute impacts. PMID:17604888

Leach, A W; Mumford, J D

2008-01-01

347

Formation of a unique zinc carbamate by CO2 fixation: implications for the reactivity of tetra-azamacrocycle ligated Zn(II) complexes.  

Science.gov (United States)

The macrocyclic ligand [13]aneN 4 ( L1, 1,4,7,10-tetra-azacyclotridecane) was reacted with Zn(II) perchlorate and CO 2 in an alkaline methanol solution. It was found that, by means of subtle changes in reaction conditions, two types of complexes can be obtained: (a) the mu 3 carbonate complex 1, {[Zn( L1)] 3(mu 3-CO 3)}(ClO 4) 4, rhombohedral crystals, space group R3 c, with pentacoordinate zinc in a trigonal bipyramidal enviroment, and (b) an unprecedenced dimeric Zn(II) carbamate structure, 2, [Zn( L2)] 2(ClO 4) 2, monoclinic crystals, space group P2 1/ n. The ligand L2 (4-carboxyl-1,4,7,10-tetra-azacyclotridecane) is a carbamate derivative of L1, obtained by transformation of a hydrogen atom of one of the NH moieties into carbamate by means of CO 2 uptake. In compound 2, the distorted tetrahedral Zn(II) coordinates to the carbamate moiety in a monodentate manner. Most notably, carbamate formation can occur upon reaction of CO 2 with the [Zn L1] (2+) complex, which implicates that a Zn-N linkage is cleaved upon attack of CO 2. Since complexes of tetra-azamacrocycles and Zn(II) are routinely applied for enzyme model studies, this finding implies that the Zn-azamacrocycle moiety generally should no longer be considered to play always only an innocent role in reactions. Rather, its reactivity has to be taken into account in respective investigations. In the presence of water, 2 is transformed readily into carbonate 1. Both compounds have been additionally characterized by solid-state NMR and infrared spectroscopy. A thorough comparison of 1 with related azamacrocycle ligated zinc(II) carbonates as well as a discussion of plausible reaction paths for the formation of 2 are given. Furthermore, the infrared absorptions of the carbamate moiety have been assigned by calculating the vibrational modes of the carbamate complex using DFT methods and the vibrational spectroscopy calculation program package SNF. PMID:18260684

Notni, Johannes; Schenk, Stephan; Görls, Helmar; Breitzke, Hergen; Anders, Ernst

2008-02-18

348

A mobile App for military operational entomology pesticide applications  

Science.gov (United States)

Multiple field studies conducted for the Deployed War Fighter Protection (DWFP) research program have generated over 80 specific guidance points for innovative combinations of pesticide application equipment, pesticide formulations, and application techniques for aerosol and residual pesticide treat...

349

33 CFR 274.7 - Authorization of pesticide use.  

Science.gov (United States)

...iv) A listing of the pesticide or pesticides the agency proposes...A) Quantity of the pesticide expected to be applied...application; (C) Method of application; ...alternatives. (vii) Analysis of possible...

2010-07-01

350

Managing Pesticide Risks for Non-Target Ecosystems with Pesticide Risk Indicators: a Multicriteria Approach  

OpenAIRE

In the search for effective pesticide risk management tools, the design of pesticide risk indicators is nowadays receiving increasing attention as a complement to more established regulatory strategies. In the present paper, we apply some recently developed pesticide risk indices and test their potential for management purposes. A pilot approach is proposed, which explores pesticide worst-case hazard scenarios at different space-time scales by means of a set of 5 ecotoxicological risk indices...

Travisi, Chiara Maria; Nijkamp, Peter; Vighi, Marco; Giacomelli, Paolo

2004-01-01

351

Catalog of total excitation-emission and total synchronous fluorescence maps with synchronous fluorescence spectra of homologated fluorescent pesticides in large use in Morocco: development of a spectrometric low cost and direct analysis as an alert method in case of massive contamination of soils and waters by fluorescent pesticides.  

Science.gov (United States)

The purpose of this research is to develop a direct spectrometric approach to monitor soils and waters, at a lower cost than the widely used chromatographic techniques; a spectrometric approach that is effective, reliable, fast, easy to implement, and without any use of organic solvents whose utilization is subject to law limitation. It could be suitable at least as an alert method in case of massive contamination. Here, we present for the first time a catalog of excitation-emission and total synchronous fluorescence maps that may be considered as fingerprints of a series of homologated pesticides, in large use in Morocco, aiming at a direct detection of their remains in agricultural soils and neighboring waters. After a large survey among farmers, agricultural workers and product distributors in two important agricultural regions of Morocco (Doukkala-Abda and Sebou basin), 48 commercial pesticides, which are fluorescent, were chosen. A multi-component spectral database of these targeted commercial pesticides was elaborated. For each pesticide, dissolved in water at the lowest concentration giving a no-noise fluorescence spectrum, the total excitation-emission matrix (TEEM), the total synchronous fluorescence matrix (TSFM) in addition to synchronous fluorescence spectra (SFS) at those offsets giving the highest fluorescence intensity were recorded. To test this preliminary multi-component database, two real soil samples, collected at a wheat field and at a vine field in the region of Doukkala, were analyzed. Remains of the commercial Pirimor (Carbamate) and Atlantis (Sulfonylurea) were identified by comparison of the recorded TEEM, TSFM, and SFS to those of the preliminary catalog at one hand, and on the basis of the results of a field pre-survey. The developed approach seems satisfactory, and the fluorimetric fingerprint database is under extension to a higher number of fluorescent pesticides in common use among the Moroccan agricultural regions. PMID:25424031

Foudeil, S; Hassoun, H; Lamhasni, T; Ait Lyazidi, S; Benyaich, F; Haddad, M; Choukrad, M; Boughdad, A; Bounakhla, M; Bounouira, H; Duarte, R M B O; Cachada, A; Duarte, A C

2014-11-27

352

Fate of pesticides during beer brewing.  

Science.gov (United States)

The fates of more than 300 pesticide residues were investigated in the course of beer brewing. Ground malt artificially contaminated with pesticides was brewed via steps such as mashing, boiling, and fermentation. Analytical samples were taken from wort, spent grain, and beer produced at certain key points in the brewing process. The samples were extracted and purified with the QuEChERS (Quick Easy Cheap Effective Rugged and Safe) method and were then analyzed by LC-MS/MS using a multiresidue method. In the results, a majority of pesticides showed a reduction in the unhopped wort and were adsorbed onto the spent grain after mashing. In addition, some pesticides diminished during the boiling and fermentation. This suggests that the reduction was caused mainly by adsorption, pyrolysis, and hydrolysis. After the entire process of brewing, the risks of contaminating beer with pesticides were reduced remarkably, and only a few pesticides remained without being removed or resolved. PMID:21401094

Inoue, Tomonori; Nagatomi, Yasushi; Suga, Keiko; Uyama, Atsuo; Mochizuki, Naoki

2011-04-27

353

Chiral pesticides: identification, description, and environmental implications.  

Science.gov (United States)

Of the 1,693 pesticides considered in this review, 1,594 are organic chemicals, 47 are inorganic chemicals, 53 are of biological origin (largely non chemical; insect,fungus, bacteria, virus, etc.), and 2 have an undetermined structure. Considering that the EPA's Office of Pesticide Programs found 1,252 pesticide active ingredients(EPA Pesticides Customer Service 2011), we consider this dataset to be comprehensive; however, no direct comparison of the compound lists was undertaken. Of all pesticides reviewed, 482 (28%) are chiral; 30% are chiral when considering only the organic chemical pesticides. A graph of this distribution is shown in Fig. 7a. Each pesticide is classified with up to three pesticidal utilities (e.g., fungicide, plant growth regulator, rodenticide, etc.), taken first from the Pesticide Manual as a primary source, and the Compendium of Common Pesticide Names website as a secondary source. Of the chiral pesticides, 195 (34%) are insecticides (including attractants, pheromones, and repellents), 150 (27%) are herbicides (including plant growth regulators and herbicide safeners), 104 (18%) are fungicides, and 55 (10%)are acaricides. The distribution of chiral pesticides by utility is shown in Fig. 7b,including categories of pesticides that make up 3%t or less of the usage categories.Figure 7c shows a similar distribution of non chiral pesticide usage categories. Of the chiral pesticides, 270 (56%) have one chiral feature, 105 (22%) have two chiral features, 30 (6.2%) have three chiral features, and 29 (6.0%) have ten or more chiral features.Chiral chemicals pose many difficulties in stereospecific synthesis, characterization, and analysis. When these compounds are purposely put into the environment,even more interesting complications arise in tracking, monitoring, and predicting their fate and risks. More than 475 pesticides are chiral, as are other chiral contaminants such as pharmaceuticals, polychlorinated biphenyls, brominated flame retardants, synthetic musks, and their degradates (Kallenborn and Hiihnerfuss 2001;Heeb et al. 2007; Hihnerfuss and Shah 2009). The stereoisomers of pesticides can have widely different efficacy, toxicity to nontarget organisms, and metabolic rates in biota. For these reasons, it is important to first be aware of likely fate and effect differences, to incorporate molecular asymmetry insights into research projects, and to study the individual stereoisomers of the applied pesticide material.With the advent of enantioselective chromatography techniques, the chirality of pesticides has been increasingly studied. While the ChirBase (Advanced ChemistryDevelopment 1997-2010) database does not include all published chiral analytical separations, it does contain more than 3,500 records for 146 of the 482 chiral pesticides (30%). The majority of the records are found in the liquid chromatography database (2,677 or 76%), followed by the gas chromatography database (652 or 18%),and the capillary electrophoresis database (203 or 6%). The finding that only 30% of the chiral pesticides covered in this review have entries in ChirBase highlights the need for expanded efforts to develop additional enantioselective chromatographic methods. Other techniques (e.g., nuclear magnetic resonance and other spectroscopy)are available for investigation of chiral compounds, but often are not utilized because of cost, complexity, or simply not recognizing that a pesticide is chiral.In this review, we have listed and have briefly described the general nature of chiral fungicides, herbicides, insecticides, and other miscellaneous classes. A data-set generated for this review contains 1,693 pesticides, the number of enantioselective separation records in ChirBase, pesticide usage class, SMILES structure string and counts of stereogenic centers. This dataset is publically available for download at the following website: http://www.epa.gov/heasd/products/products.html. With the information herein coupled to the publically accessible dataset, we can begin to develop the tools to handle molecular asymmetry as

Ulrich, Elin M; Morrison, Candice N; Goldsmith, Michael R; Foreman, William T

2012-01-01

354

Multiresidue analysis of pesticides in fruits and vegetables using disposable pipette extraction (DPX) and micro-luke method.  

Science.gov (United States)

Simple and rapid methods for the analysis of pesticides in produce samples have been developed. The current study involves analysis of nonpolar and polar pesticides using GC-ECD and GC-NPD, respectively. The nonpolar pesticides were extracted using disposable pipette extraction (DPX) following a preliminary acetone extraction based on the Luke method. Recoveries of the fortified pesticides ranged between 70.5 and 110.0%, with relative standard deviations (% RSD) below 10% for most target analytes. From calibration plots, the limits of detection (LOD) were determined to be 0.99. A micro-Luke method was adapted and used for the analysis of polar pesticides, which greatly reduces the volumes of solvent and time for sample preparation. This new method of analysis, combining DPX and micro-Luke, was compared directly with the modified Luke method for analysis of pesticides in produce samples over a 9 week period. This study validates the suitability for routine analysis of pesticides in acetone extract of fruits and vegetables using the proposed DPX and micro-Luke method. PMID:20218611

Guan, Hongxia; Brewer, William E; Garris, Sherry T; Craft, Chanin; Morgan, Stephen L

2010-05-26

355

Proper pesticide use [videorecording] : monitoring the impact of pesticides with nuclear techniques.  

International Nuclear Information System (INIS)

Food safety experts from the IAEA are conducting research using nuclear techniques to evaluate the impact of pesticide use on the environment, in food products and surface waters. The project aims to improve agricultural management practices, raise awareness on pesticide monitoring and ultimately develop a simple, "rapid-alert" test for measuring potential contamination from pesticides.

356

Presence of organophosphorus pesticide oxygen analogs in air samples  

Science.gov (United States)

A number of recent toxicity studies have highlighted the increased potency of oxygen analogs (oxons) of several organophosphorus (OP) pesticides. These findings were a major concern after environmental oxons were identified in environmental samples from air and surfaces following agricultural spray applications in California and Washington State. This paper reports on the validity of oxygen analog measurements in air samples for the OP pesticide, chlorpyrifos. Controlled environmental and laboratory experiments were used to examine artificial formation of chlorpyrifos-oxon using OSHA Versatile Sampling (OVS) tubes as recommended by NIOSH method 5600. Additionally, we compared expected chlorpyrifos-oxon attributable to artificial transformation to observed chlorpyrifos-oxon in field samples from a 2008 Washington State Department of Health air monitoring study using non-parametric statistical methods. The amount of artificially transformed oxon was then modeled to determine the amount of oxon present in the environment. Toxicity equivalency factors (TEFs) for chlorpyrifos-oxon were used to calculate chlorpyrifos-equivalent air concentrations. The results demonstrate that the NIOSH-recommended sampling matrix (OVS tubes with XAD-2 resin) was found to artificially transform up to 30% of chlorpyrifos to chlorpyrifos-oxon, with higher percentages at lower concentrations (method. Failure to conduct laboratory analysis for chlorpyrifos-oxon may result in underestimation of total pesticide concentration when using XAD-2 resin matrices for occupational or residential sampling. Alternative methods that can accurately measure both OP pesticides and their oxygen analogs should be used for air sampling, and a toxicity equivalent factor approach should be used to determine potential health risks from exposures.

Armstrong, Jenna L.; Fenske, Richard A.; Yost, Michael G.; Galvin, Kit; Tchong-French, Maria; Yu, Jianbo

2013-02-01

357

Monitoring of pesticides in human milk  

International Nuclear Information System (INIS)

After establishing proper analytical methodology for multiple pesticide residues, cotton-growing areas of Multan Division of Pakistan were surveyed and 40 samples of human milk from cotton pickers were collected during two crop seasons. Screening of these samples showed 72.5% contamination with 19 different pesticides/metabolites. The most frequently occurring pesticides were DDT and its metabolites, dimethoate, cyhalothrin, monocrotophos, profenofos and quinalphos. (author)

358

Pesticide Risk Valuation in Empirical Economics  

OpenAIRE

Pesticide use in agriculture poses several risks to both human health and non-target agro-ecosystems. Due to lack of information on the monetary value of reducing pesticide risks, it is difficult to perform an economic analysis that addresses social efficiency of policy and draws conclusions about the appropriate degree of regulation.The aim of the current paper is to present a critical overview of the empirical literature on pesticide risk valuation that provides disaggregate willingness-to-...

Nijkamp, Peter; Travisi, Chiara Maria; Vindigni, Gabriella

2002-01-01

359

Pesticides in groundwater - two examples from Africa  

OpenAIRE

To produce cash crops, pesticides are needed to a much higher degree in the tropics than in the temperate zones. When this need to use pesticides is coupled with low education among the users it's a perfect basis for environmental problems. However, the highest risk of pesticide contamination of water resources, including groundwater, is often not the direct use in agricultural fields, but point sources and "old sins". An additional problem is that substances that have been phased out in indu...

Kylin, Henrik; Meinhardt, Ralph; Kishimba, Michael; Bouwman, Henk

2005-01-01

360

Pesticides reduce regional biodiversity of stream invertebrates  

OpenAIRE

The biodiversity crisis is one of the greatest challenges facing humanity, but our understanding of the drivers remains limited. Thus, after decades of studies and regulation efforts, it remains unknown whether to what degree and at what concentrations modern agricultural pesticides cause regional-scale species losses. We analyzed the effects of pesticides on the regional taxa richness of stream invertebrates in Europe (Germany and France) and Australia (southern Victoria). Pesticides caused ...

Beketov, Mikhail A.; Kefford, Ben J.; Scha?fer, Ralf B.; Liess, Matthias

2013-01-01

361

Biosensors for Pesticide Detection: New Trends  

OpenAIRE

Due to the large amounts of pesticides commonly used and their impact on health, prompt and accurate pesticide analysis is important. This review gives an overview of recent advances and new trends in biosensors for pesticide detection. Optical, electrochemical and piezoelectric biosensors have been reported based on the detection method. In this review biosensors have been classified according to the immobilized biorecognition element: enzymes, cells, antibodies and, more rarely, DNA. The us...

Jean-Louis Marty; Beatriz Prieto-Simón; Audrey Sassolas

2012-01-01

362

Determination of Pesticide Residues in Cannabis Smoke  

OpenAIRE

The present study was conducted in order to quantify to what extent cannabis consumers may be exposed to pesticide and other chemical residues through inhaled mainstream cannabis smoke. Three different smoking devices were evaluated in order to provide a generalized data set representative of pesticide exposures possible for medical cannabis users. Three different pesticides, bifenthrin, diazinon, and permethrin, along with the plant growth regulator paclobutrazol, which are readily available...

Nicholas Sullivan; Sytze Elzinga; Raber, Jeffrey C.

2013-01-01

363

Pesticide exposure to greenhouse handgunners.  

Science.gov (United States)

The exposure of pesticide applicators in a commercial greenhouse facility was assessed. Data were collected from four handgunners who applied fluvalinate (insecticide), chlorpyrifos (insecticide), ethazol (fungicide), and dicofol (miticide). Potential exposure was measured with exposure pads placed outside all clothing of the applicator. Handwashes and air samples were also collected, as were pre- and post-exposure tank mixture samples. Pesticide penetration was measured with exposure pads placed inside protective clothing. When all exposure assessments were normalized for spray rate, it was determined that applicators were at significantly greater potential dermal risk (excluding hands) from fluvalinate. The normalized air samples showed significantly more exposure to the applicator from ethazol. Exposure to outside pads was primarily (84%) to the legs of the applicators. Ethazol penetrated Tyvek coveralls more readily than the other compounds. Tank mixture analyses suggested that the wettable powder formulations were not well-mixed. PMID:2774669

Stamper, J H; Nigg, H N; Mahon, W D; Nielsen, A P; Royer, M D

1989-01-01

364

Evidence of carbamate resistance in urban populations of Anopheles gambiae s.s. mosquitoes resistant to DDT and deltamethrin insecticides in Lagos, South-Western Nigeria  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Resistance monitoring is essential in ensuring the success of insecticide based vector control programmes. This study was carried out to assess the susceptibility status of urban populations of Anopheles gambiae to carbamate insecticide being considered for vector control in mosquito populations previously reported to be resistant to DDT and permethrin. Methods Two – three day old adult female Anopheles mosquitoes reared from larval collections in 11 study sites from Local Government Areas of Lagos were exposed to test papers impregnated with DDT 4%, deltamethrin 0.05% and propoxur 0.1% insecticides. Additional tests were carried out to determine the susceptibility status of the Anopheles gambiae population to bendiocarb insecticide. Members of the A. gambiae complex, the molecular forms, were identified by PCR assays. The involvement of metabolic enzymes in carbamate resistance was assessed using Piperonyl butoxide (PBO synergist assays. The presence of kdr-w/e and ace-1R point mutations responsible for DDT-pyrethroid and carbamate resistance mechanisms was also investigated by PCR. Results Propoxur resistance was found in 10 out of the 11 study sites. Resistance to three classes of insecticides was observed in five urban localities. Mortality rates in mosquitoes exposed to deltamethrin and propoxur did not show any significant difference (P?>?0.05 but was significantly higher (P?A. gambiae s.s (M form. The kdr -w point mutation at allelic frequencies between 45%-77% was identified as one of the resistant mechanisms responsible for DDT and pyrethroid resistance. Ace-1R point mutation was absent in the carbamate resistant population. However, the possible involvement of metabolic resistance was confirmed by synergistic assays conducted. Conclusion Evidence of carbamate resistance in A. gambiae populations already harbouring resistance to DDT and permethrin is a clear indication that calls for the implementation of insecticide resistance management strategies to combat the multiple resistance identified.

Oduola Adedayo O

2012-06-01

365

Evidence of multiple mechanisms providing carbamate and organophosphate resistance in field An. gambiae population from Atacora in Benin.  

Science.gov (United States)

BackgroundInsecticide resistance in Anopheles gambiae s.l is a major concern to malaria vector control programmes. In West Africa, resistance is mainly due to target¿site insensitivity arising from a single point mutation. Metabolic-based resistance mechanisms have also been implicated and are currently being investigated in west Africa. The aim of this study is to better understand the origins of carbamate and organophosphate resistance in An. gambiae population from Atacora, Benin in West Africa.MethodsAnopheles mosquitoes were reared from larvae collected in two districts (Kouandé and Tanguiéta) of the Atacora department. Mosquitoes were then exposed to WHO impregnated papers. Four impregnated papers were used: carbamates (0.1% bendiocarb, 0.1% propoxur) and organophosphates (0.25% pirimiphos methyl, 1% fenitrothion). PCR assays were run to determine the members of the An. gambiae complex, as well as phenotypes for insensitive acetylcholinesterase (AChE1). Biochemical assays were also carried out to detect any increase in the activity of enzyme typically involved in insecticide metabolism (oxidase, esterase and glutathion-S-transferase).Results769 female of An. gambiae mosquitoes from Kouandé and Tanguiéta were exposed to bendiocarb, propoxur, pirimiphos methyl and fenitrothion. Bioassays showed resistance with low mortality to bendiocarb (78.57% to 80.17%), propoxur (77.21% to 89.77%), and fenitrothion (89.74% to 92.02%). On the other hand, the same populations of An. gambiae from Kouandé and Tanguiéta showed high susceptibility to pirimiphos methyl with recorded mortality of 99.02% and 100% respectively. The low rate of ace-1R allele frequency (3.75% among survivors and 0.48% among dead) added to the high proportion of homozygous susceptible specimens which survived the WHO bioassays (8/28), suggest that the ace-1 mutation could not entirely explain Anopheles gambiae resistance to carbamate and organophosphate. Biochemical assays suggest that resistance in this population is mediated by metabolic resistance with elevated level of GST, MFO and NSE compared to a susceptible strain An. gambiae Kisumu.Conclusions Anopheles gambiae populations resistance from Atacora is multifactorial and includes target-site mutation and metabolic mechanism. The co-implication of both resistance mechanisms in An. gambiae s.l may be a serious obstacle for the future success of malaria control operations based on LLINs and IRS. PMID:25443399

Aïkpon, Rock; Sèzonlin, Michel; Ossè, Razaki; Akogbéto, Martin

2014-12-01

366

Behavioural and insecticidal effects of organophosphate-, carbamate- and pyrethroid-treated mosquito nets against African malaria vectors.  

Science.gov (United States)

Three insecticides - the pyrethroid deltamethrin, the carbamate carbosulfan and the organophosphate chlorpyrifos-methyl - were tested on mosquito nets in experimental huts to determine their potential for introduction as malaria control measures. Their behavioural effects and efficacy were examined in Anopheles gambiae Giles s.s. (Diptera: Culicidae) and Anopheles funestus Giles s.s. in Muheza, Tanzania, and in Anopheles arabiensis Patton and Culex quinquefasciatus Say in Moshi, Tanzania. A standardized dosage of 25 mg/m(2) plus high dosages of carbosulfan (50 mg/m(2), 100 mg/m(2) and 200 mg/m(2)) and chlorpyrifos-methyl (100 mg/m(2)) were used to compare the three types of insecticide. At 25 mg/m(2), the rank order of the insecticides for insecticide-induced mortality in wild An. gambiae and An. funestus was, respectively, carbosulfan (88%, 86%) > deltamethrin (79%, 78%) > chlorpyrifos-methyl (35%, 53%). The rank order of the insecticides for blood-feeding inhibition (reduction in the number of blood-fed mosquitoes compared with control) in wild An. gambiae and An. funestus was deltamethrin > chlorpyrifos-methyl > carbosulfan. Carbosulfan was particularly toxic to endophilic anophelines at 200 mg/m(2), killing 100% of An. gambiae and 98% of An. funestus that entered the huts. It was less effective against the more exophilic An. arabiensis (67% mortality) and carbamate-resistant Cx quinquefasciatus (36% mortality). Carbosulfan deterred anophelines from entering huts, but did not deter carbamate-resistant Cx quinquefasciatus. Deltamethrin reduced the proportion of insects engaged in blood-feeding, probably as a consequence of contact irritancy, whereas carbosulfan seemed to provide personal protection through deterred entry or perhaps a spatial repellent action. Any deployment of carbosulfan as an individual treatment on nets should be carried out on a large scale to reduce the risk of diverting mosquitoes to unprotected individuals. Chlorpyrifos-methyl was inferior to deltamethrin in terms of mortality and blood-feeding inhibition and would be better deployed on a net in combination with a pyrethroid to control insecticide-resistant mosquitoes. PMID:19941597

Malima, R C; Oxborough, R M; Tungu, P K; Maxwell, C; Lyimo, I; Mwingira, V; Mosha, F W; Matowo, J; Magesa, S M; Rowland, M W

2009-12-01

367

76 FR 36479 - Receipt of a Pesticide Petition Filed for Residues of Pesticide Chemicals in or on Various...  

Science.gov (United States)

...make a final determination on this pesticide...regulations for residues of pesticides...regulations for residues of pesticides...part 180 for residues of the insecticide thiamethoxam...procedures and determination by liquid...

2011-06-22

368

78 FR 79359 - Receipt of Several Pesticide Petitions Filed for Residues of Pesticide Chemicals in or on Various...  

Science.gov (United States)

...40 CFR part 180 for residues of pesticide chemicals...EPA can make a final determination on these pesticide...of regulations for residues of pesticides in or...180 for the combined residues of the insecticide spinetoram,...

2013-12-30

369

78 FR 56185 - Receipt of Several Pesticide Petitions Filed for Residues of Pesticide Chemicals in or on Various...  

Science.gov (United States)

...40 CFR part 180 for residues of pesticide chemicals...EPA can make a final determination on these pesticide...of regulations for residues of pesticides in or...40 CFR part 180 for residues of the insecticide diflubenzuron,...

2013-09-12

370

Application of nuclear techniques in pesticide research  

International Nuclear Information System (INIS)

Nuclear techniques are commonly used in studying the environmental fate of pesticides in soil, water and other environmental matrices and the metabolism of pesticides in animals and plants, as well as in the identification of the degradation products of pesticides formulations. Stable isotopes such as /sup 13/C and /sup 18/O are used in determining the structure of degradation products of pesticides and in understanding the biochemical mechanisms involved in the transformation. Radioisotopes such as tritium, /sup 14/C and/sup 32/P as traces in pesticides research are well established. A pesticide molecule 'labelled' with radioactive atom can easily be traced among score of natural, non-labelled chemicals found in soil, water, animals or plant tissues and other environmental matrices by using radiation detectors. The labelled pesticide and its degradation products can be separated from other chemicals by chromatographic techniques and their amounts estimated by quantifying the radioactivity associated with them. This technique is very sensitive to minute quantities, is reliable and save time that would otherwise be required for tedious purification procedures. For examples, residues of pesticides, which are tightly bound to an environmental matrix and cannot be extracted with a solvent, can be estimated by using a radiotracer technique. In the present paper formation and study of bound residues of pesticides by using radiotracer techniques will be discussed. (author)r techniques will be discussed. (author)

371

Sorption of pesticides to aquifer minerals  

DEFF Research Database (Denmark)

This paper summarizes results from a work were the sorption of five pesticides on seven minerals were studied in order to quantify the adsorption to different mineral surfaces. Investigated mineral phases are: quartz, calcite, kaolinite, a-alumina, and three iron oxides (2-line ferrihydrite, goethite, lepidocrocite). Selected pesticides are: atrazine, isoproturon, mecoprop, 2,4-D, and bentazone. The results demonstrate that pesticides adsorb to pure mineral surfaces. However, the size of the adsorption depends on the type of pesticide and the type of mineral.

Clausen, Liselotte; Fabricius, Ida Lykke

2000-01-01

372

Protein phosphorylation pathways disruption by pesticides  

Directory of Open Access Journals (Sweden)

Full Text Available Phosphosites in the human proteome represent an excellent source of potential biomarkers of pesticide toxicity. In fact, experimental animal models as well as in vitro studies have revealed phosphorylation disruption associated to metabolic regulation, hormone signaling, neuronal function and differentiation, cell survival and death. Due to their estrogen-mimicking ability, pesticides are considered as prime etiological suspects of increasing tumor incidence. Evidences of alterations in the signal transduction pathways involved in the tumor progression stage of pesticides were also provided. Despite progress in understanding the effect of pesticides on the human phosphorproteome and their health outcomes, it remains a complex issue to be studied. By now, the potential impact of pesticides in epigenetic phosphorylation pathways remains poorly explored. In addition, studies involving pesticides mixtures effects are needed. This review updates and provides a comprehensive discussion on the molecular and biochemical events underlying protein phosphorylation pathway disruption caused by pesticides most frequently detected in human tissues and fluids, such as organochlorine pesticides and organophosphates. The link between epidemiological studies and experimental approaches is also considered. Future challenges, such as micro-array phosphoproteome studies to complement gene expression arrays to understand the mechanisms involved in pesticide toxicology are briefly discussed.

Gladis Magnarelli

2013-10-01

373

Effect of Endocrine Disruptor Pesticides: A Review  

Directory of Open Access Journals (Sweden)

Full Text Available Endocrine disrupting chemicals (EDC are compounds that alter the normal functioning of the endocrine system of both wildlife and humans. A huge number of chemicals have been identified as endocrine disruptors, among them several pesticides. Pesticides are used to kill unwanted organisms in crops, public areas, homes and gardens, and parasites in medicine. Human are exposed to pesticides due to their occupations or through dietary and environmental exposure (water, soil, air. For several years, there have been enquiries about the impact of environmental factors on the occurrence of human pathologies. This paper reviews the current knowledge of the potential impacts of endocrine disruptor pesticides on human health.

Benoit Roig

2011-06-01

374

40 CFR 158.2110 - Microbial pesticides data requirements.  

Science.gov (United States)

...including all use patterns, food and nonfood uses for terrestrial...Additional data requirements for genetically modified microbial pesticides. Additional requirements for genetically modified microbial pesticides may...

2010-07-01

375

Poly(methyltetradecylsiloxane) immobilized onto silica for extraction of multiclass pesticides from surface waters.  

Science.gov (United States)

A new material based on poly(methyltetradecylsiloxane) (PMTDS) thermally immobilized onto a silica support has been tested as a sorbent for the solid-phase extraction (SPE) from water of several pesticides used in soybean cultivation. The SPE methodology was developed and validated for six of these pesticides (imazethapyr, imazaquin, metsulfuron-methyl, bentazone, chlorimuron-ethyl and tebuconazole) according to the International Conference on Harmonization directives and the results were compared with those obtained with a commercial C18 SPE cartridge. The PMTDS-based sorbent gives results similar to the commercial sorbent with recoveries and precisions in agreement with directives for residue analysis. The quantification limits, after concentration, of all the pesticides evaluated were 1.0 microg L(-1), below the levels imposed by the principal regulatory agencies. The PMTDS-based sorbent preparation is fast, easy and reproducible and the cartridges are less expensive than similar commercial SPE materials. PMID:17386471

Faria, Anizio M; Maldaner, Liane; Santana, César C; Jardim, Isabel C S F; Collins, Carol H

2007-01-16

376

PestLCI - A new model for estimation of inventory data for pesticide applications  

DEFF Research Database (Denmark)

PestLCI is a new, modular model for estimation of pesticide emissions from field application to the different environmental compartments. It calculates emission fractions to the air, water, soil and groundwater compartments of the environment based on generally available information about: Type and time of application, crop species and development stage, and properties of the pesticide active ingredients. The required physical-chemical information on the 69 organic pesticides approved for field-use in Denmark is included in the model as a data base. So is the relative leaf area for 28 common European crops on 2-5 development stages together with meteorological data for 12 stations in Denmark. The use and capability of the model is illustrated through Danish case studies but the modular structure of the model will allow its adaptation to conditions valid for other regions.

Birkved, Morten; Hauschild, Michael Zwicky

2003-01-01

377

Chiral separation on sulfonated cellulose tris(3,5-dimethylphenyl carbamate)-coated zirconia monolith by capillary electro chromatography  

International Nuclear Information System (INIS)

Sulfonated cellulose tris(3,5-dimethylphenyl carbamate) (SCDMPC)-coated zirconia monolith (ZM) was used as the chiral stationary phase in capillary electro chromatography for separation of enantiomers of ten chiral compounds in acetonitrile (ACN)-phosphate buffer mixtures as the eluent. Influences of the ACN content, buffer concentration and pH on chiral separation have been investigated. Separation data on SCDMPC-ZM have been compared with those on CDMPC-ZM. Resolution factors were better on SCDMPC-ZM than CDMPC-ZM while retention factors were in general shorter on the former than the latter. Best chiral resolutions on SCDMPC-ZM were obtained with the eluent of 50% ACN containing 50 mM phosphate at pH around 4

378

Determination of bromoxynil and ioxynil in the presence of carbamates by supported liquid membrane-liquid chromatography in river waters  

Directory of Open Access Journals (Sweden)

Full Text Available Sample pre-treatment and enrichment using the supported liquid membrane (SLM technique for the determination of phenolic nitrile herbicides in presence of carbamates in river water samples was investigated. The uncharged herbicide molecules from the flowing aqueous solution diffuse through an immobilized water-immiscible organic solvent, supported by a porous polytetrafluoroethylene (PTFE membrane, and trapped in a stagnant acidic acceptor phase in an ionic form. Using n-undecane as a membrane solvent, the SLM extraction methodology was successfully used for the enrichment and separation of phenolic nitrile herbicides in environmental waters with extraction efficiencies of 60% or better. A RDS (% of 2.1 and 1.8 was obtained for the extraction of ioxynil and bromoxynil from river water, respectively.

Titus Motswadi Maswabi

2003-12-01

379

A review of ethyl carbamate and polycyclic aromatic hydrocarbon contamination risk in cachaça and other Brazilian sugarcane spirits.  

Science.gov (United States)

Sixteen polycyclic aromatic hydrocarbons (PAHs) have been identified in Brazilian sugarcane spirits. Contamination sources are: sugarcane burn before harvest and petroleum derivatives. PAHs concentration in spirits produced from burned cane was about 2-3 times higher than those from unburned cane. Benzo(a)pyrene (BaP) is present at less than 1%, and therefore is not a representative marker of cachaça contamination by PAHs. Ethyl carbamate (EC) is produced during both fermentation and distillation. During distillation, cupric ions may catalyse the conversion of cyanide to EC. In discontinuous distillation, the use of the heart fraction for bottling cachaça considerably decreases its concentration. In the continuous process, in which there is no separation of distillate, it is highly recommended to couple cooling devices and reflux systems to the distillation column. Consumers are at a greater risk of EC exposure from cachaça than from any other spirit. PMID:24295690

Riachi, L G; Santos, A; Moreira, R F A; De Maria, C A B

2014-04-15

380

The Mancozeb-containing carbamate fungicide tattoo induces mild oxidative stress in goldfish brain, liver, and kidney.  

Science.gov (United States)

Tattoo belongs to the group of carbamate fungicides and contains Mancozeb (ethylene(bis)dithiocarbamate) as its main constituent. The toxicity of Mancozeb to living organisms, particularly fish, is not resolved. This work investigated the effects of 96 h of exposure to 3, 5, or 10 mg L(-1) of Tattoo (corresponding to 0.9, 1.5, or 3 mg L(-1) of Mancozeb) on the levels of oxidative stress markers and the antioxidant enzyme system of brain, liver, and kidney of goldfish, Carassius auratus). In liver, Tattoo exposure resulted in increased activities of superoxide dismutase (SOD) by 70%-79%, catalase by 23%-52% and glutathione peroxidase (GPx) by 49%. The content of protein carbonyls (CP) in liver was also enhanced by 92%-125% indicating extensive damage to proteins. Similar increases in CP levels (by 98%-111%) accompanied by reduced glucose-6-phosphate dehydrogenase activity (by 13%-15%) was observed in kidney of fish exposed to Tattoo; however, SOD activity increased by 37% in this tissue after treatment with 10 mg L(-1) Tattoo. In brain, a rise in lipid peroxide level (by 29%) took place after exposure to 10 mg L(-1) Tattoo and was accompanied by elevation of high-molecular mass thiols (by 14%). Tattoo exposure also resulted in a concentration-dependent decrease in glutathione reductase activity (by 26%-37%) in brain. The data collectively show that exposure of goldfish to 3-10 mg L(-1) of the carbamate fungicide Tattoo resulted in the development of mild oxidative stress and activation of antioxidant defense systems in goldfish tissues. PMID:23436297

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

2014-11-01

381

Rapid detection of chlorpyrifos pesticide residue concentration in agro-product using Raman spectroscopy  

Science.gov (United States)

Different chemicals are sprayed in fruits and vegetables before and after harvest for better yield and longer shelf-life of crops. Cases of pesticide poisoning to human health are regularly reported due to excessive application of such chemicals for greater economic benefit. Different analytical technologies exist to detect trace amount of pesticides in fruits and vegetables, but are expensive, sample destructive, and require longer processing time. This study explores the application of Raman spectroscopy for rapid and non-destructive detection of pesticide residue in agricultural products. Raman spectroscopy with laser module of 785 nm was used to collect Raman spectral information from the surface of Gala apples contaminated with different concentrations of commercially available organophosphorous (48% chlorpyrifos) pesticide. Apples within 15 days of harvest from same orchard were used in this study. The Raman spectral signal was processed by Savitzky-Golay (SG) filter for noise removal, Multiplicative Scatter Correction (MSC) for drift removal and finally polynomial fitting was used to eliminate the fluorescence background. The Raman spectral peak at 677 cm-1 was recognized as Raman fingerprint of chlorpyrifos. Presence of Raman peak at 677 cm-1 after fluorescence background removal was used to develop classification model (presence and absence of pesticide). The peak intensity was correlated with actual pesticide concentration obtained using Gas Chromatography and MLR prediction model was developed with correlation coefficient of calibration and validation of 0.86 and 0.81 respectively. Result shows that Raman spectroscopy is a promising tool for rapid, real-time and non-destructive detection of pesticide residue in agro-products.

Dhakal, Sagar; Peng, Yankun; Li, Yongyu; Chao, Kuanglin; Qin, Jianwei; Zhang, Leilei; Xu, Tianfeng

2014-05-01

382

Multi-Residue Analysis of Pesticides in Pistachio Using Gas Chromatography-Mass Spectrometry (GC/MS  

Directory of Open Access Journals (Sweden)

Full Text Available Background: Analysis of pesticide residues in food and other environmental commodities have become an essential requirement for consumers, producers, food inspectors and authorities. This study is focused on validation of an accurate, rapid and reliable method for multi-residual analysis of pesticides in pistachio as a strategic crop for export and one of the main nuts in Iranian food basket. Methods: We developed a "Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS method based on spiking blank samples and used the data for drawing calibration curves instead of standard solutions. Sample preparations were developed for determination of 12 pesticide residues in pistachio by gas chromatography-mass spectrometry (GC/MS. Results: Recovery of pesticides at 5 concentration levels (n=3 was in the range of 81.40% - 93.08 %. The method proved to be repeatable in the majority of samples with relative standard deviation (RSD of lower than 20%. The limits of detection and quantification for all pesticides were 2 ppb and 10 ppb, respectively. Conclusion: The calibration curves of pesticides were linear in the range of 10-500 (ng/g and correlation coefficient of entire pesticides was higher than 0.994. The recovery of pesticides at 5 concentration levels (n=3 was in range of 81.41- 91.80 %. The method was proved to be repeatable with the majority of RSDs being lower than 20%. The limits of detection and quantification for all pesticides were 2 and 10 ppb, respectively. The recoveries and repeatabilities were in accordance with the criteria set by SANCO Guideline (Commission of the European Communities, 2006.

Azadeh Emami

2014-12-01

383

Vulnerabilidades e situações de riscos relacionados ao uso de agrotóxicos na fruticultura irrigada / Vulnerability and risk situations related to the use of pesticides in irrigated fruit farming  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese A determinação de situações de riscos na população que faz uso de agrotóxico é complexa. O objetivo desse estudo foi conhecer o contexto social, econômico e cultural e algumas das vulnerabilidades para a saúde relacionadas com o processo produtivo químico dependente da fruticultura do Vale do São Fr [...] ancisco. Questionário semiestruturado foi aplicado a uma amostra aleatória de trabalhadores rurais, para obtenção de informações socioeconômicas e culturais, assim como a morbidade relacionada com intoxicação por agrotóxicos. Os trabalhadores rurais da região têm em sua maioria baixo grau de escolaridade, sendo esta uma importante vulnerabilidade para compreensão da rotulagem dos agrotóxicos e sua implicação toxicológica e ambiental. Foi observado uso indiscriminado de agrotóxicos em condições inseguras de trabalho que comprometem a saúde dos expostos. A sintomatologia sugestiva de intoxicação por agrotóxicos aponta para quadros relacionados com exposição à organofosforados, carbamatos e piretróides, em congruência com os biocidas utilizados na fruticultura. 7% da população estudada referiram ter sofrido pelo menos um caso de intoxicação no decorrer da vida. A assistência técnica relacionada com o manejo de agrotóxicos é precária e não se observaram ações de proteção no âmbito da saúde, do trabalho, da previdência ou do ambiente. Estas vulnerabilidades institucionais corroboram aquelas relacionadas com o modelo tecnológico que objetiva meramente a produtividade e o rendimento financeiro. Abstract in english Determining the risks in a population that uses pesticides is a complex task. The purpose of this study was to outline the socio-economic and cultural context and some of the health vulnerabilities related to fruit production in the São Francisco River valley in Brazil. Semi-structured questionnaire [...] s were applied to random samples of farm workers to obtain data on social, economic and cultural characteristics, as well as the morbidity related to pesticide poisoning. These farm workers have low level of schooling, and this is a major vulnerability for understanding the labels of pesticides and their toxicological and environmental implications. This study found indiscriminate use of pesticides in unsafe and unhealthy conditions of work that compromise the health of exposed workers. Symptoms suggestive of pesticide poisoning are closely related to exposure to organophosphates, carbamates and pyrethroid, which match pesticides used in fruit farming. Seven percent of the population reported poisoning events at some point in their lives. Technical assistance related to the management of pesticides is poor, and actions toward the improvement of health, environment and work conditions were not seen. These vulnerabilities corroborate those related to a technological model that aims merely at productivity and good financial performance.

Cheila Nataly Galindo, Bedor; Lara Oliveira, Ramos; Paulo José, Pereira; Marco Antônio Vasconcelos, Rêgo; Antonio Carlos, Pavão; Lia Giraldo da Silva, Augusto.

2009-03-01

384

Vulnerabilidades e situações de riscos relacionados ao uso de agrotóxicos na fruticultura irrigada / Vulnerability and risk situations related to the use of pesticides in irrigated fruit farming  

Scientific Electronic Library Online (English)

Full Text Available SciELO Public Health | Language: Portuguese Abstract in portuguese A determinação de situações de riscos na população que faz uso de agrotóxico é complexa. O objetivo desse estudo foi conhecer o contexto social, econômico e cultural e algumas das vulnerabilidades para a saúde relacionadas com o processo produtivo químico dependente da fruticultura do Vale do São Fr [...] ancisco. Questionário semiestruturado foi aplicado a uma amostra aleatória de trabalhadores rurais, para obtenção de informações socioeconômicas e culturais, assim como a morbidade relacionada com intoxicação por agrotóxicos. Os trabalhadores rurais da região têm em sua maioria baixo grau de escolaridade, sendo esta uma importante vulnerabilidade para compreensão da rotulagem dos agrotóxicos e sua implicação toxicológica e ambiental. Foi observado uso indiscriminado de agrotóxicos em condições inseguras de trabalho que comprometem a saúde dos expostos. A sintomatologia sugestiva de intoxicação por agrotóxicos aponta para quadros relacionados com exposição à organofosforados, carbamatos e piretróides, em congruência com os biocidas utilizados na fruticultura. 7% da população estudada referiram ter sofrido pelo menos um caso de intoxicação no decorrer da vida. A assistência técnica relacionada com o manejo de agrotóxicos é precária e não se observaram ações de proteção no âmbito da saúde, do trabalho, da previdência ou do ambiente. Estas vulnerabilidades institucionais corroboram aquelas relacionadas com o modelo tecnológico que objetiva meramente a produtividade e o rendimento financeiro. Abstract in english Determining the risks in a population that uses pesticides is a complex task. The purpose of this study was to outline the socio-economic and cultural context and some of the health vulnerabilities related to fruit production in the São Francisco River valley in Brazil. Semi-structured questionnaire [...] s were applied to random samples of farm workers to obtain data on social, economic and cultural characteristics, as well as the morbidity related to pesticide poisoning. These farm workers have low level of schooling, and this is a major vulnerability for understanding the labels of pesticides and their toxicological and environmental implications. This study found indiscriminate use of pesticides in unsafe and unhealthy conditions of work that compromise the health of exposed workers. Symptoms suggestive of pesticide poisoning are closely related to exposure to organophosphates, carbamates and pyrethroid, which match pesticides used in fruit farming. Seven percent of the population reported poisoning events at some point in their lives. Technical assistance related to the management of pesticides is poor, and actions toward the improvement of health, environment and work conditions were not seen. These vulnerabilities corroborate those related to a technological model that aims merely at productivity and good financial performance.

Cheila Nataly Galindo, Bedor; Lara Oliveira, Ramos; Paulo José, Pereira; Marco Antônio Vasconcelos, Rêgo; Antonio Carlos, Pavão; Lia Giraldo da Silva, Augusto.

2009-03-01

385

Pattern of pesticide storage before pesticide self-poisoning in rural Sri Lanka  

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Full Text Available Abstract Background Deliberate self-poisoning with agricultural pesticides is the commonest means of suicide in rural Asia. It is mostly impulsive and facilitated by easy access to pesticides. The aim of this large observational study was to investigate the immediate source of pesticides used for self-harm to help inform suicide prevention strategies such as reducing domestic access to pesticides. Methods The study was conducted in a district hospital serving an agricultural region of Sri Lanka. Patients who had self-poisoned with pesticides and were admitted to the adult medical wards were interviewed by study doctors following initial resuscitation to identify the source of pesticides they have ingested. Results Of the 669 patients included in the analysis, 425 (63.5% were male; the median age was 26 (IQR 20-36. In 511 (76% cases, the pesticides had been stored either inside or immediately outside the house; among this group only eight patients obtained pesticides that were kept in a locked container. Ten percent (n = 67 of the patients used pesticides stored in the field while 14% (n = 91 purchased pesticides from shops within a few hours of the episode. The most common reasons for choosing the particular pesticide for self-harm were its easy accessibility (n = 311, 46% or its popularity as a suicide agent in their village (n = 290, 43%. Conclusion Three quarters of people who ingested pesticides in acts of self-harm used products that were available within the home or in close proximity; relatively few patients purchased the pesticide for the act. The study highlights the importance of reducing the accessibility of toxic pesticides in the domestic environment.

Eddleston Michael

2009-11-01

386

Toxicity of Pesticides. Agrichemical Fact Sheet 2.  

Science.gov (United States)

This fact sheet gives the acute oral and dermal toxicity (LD 50) of over 250 pesticides in lab animals. The chemicals are categorized as fungicides, herbicides, insecticides, or miscellaneous compounds. One or more trade names are given for each pesticide. In addition, a brief explanation of toxicity determination is given. (BB)

Hock, Winand K.

387

77 FR 59106 - Glufosinate Ammonium; Pesticide Tolerances  

Science.gov (United States)

...chronic dietary analysis for crops that...Anticipated residue and percent crop...residue levels of pesticide residues in food...tolerance-level residues. The chronic dietary exposure analysis was performed using anticipated residues from field trial...chronic dietary pesticide exposures...

2012-09-26

388

77 FR 23625 - Quizalofop Ethyl; Pesticide Tolerances  

Science.gov (United States)

...anticipated residue and/or PCT...Tolerance level residues and/or 100...dietary exposure analysis and risk assessment...models used in pesticide exposure assessment...levels based on analysis of the residue field trial...for Setting Pesticide...

2012-04-20

389

QA/QC in pesticide residue analysis  

International Nuclear Information System (INIS)

This paper outlines problems related to pesticide residue analysis in a regulatory laboratory that are related to: availability of reference materials, as over 1000 pesticide active ingredients are currently in use and over 400 crops represent a large part of a healthy diet; analysis time; availability of samples in sufficient numbers; uncertainties of the procedures

390

Introduction to Indoor Air Quality: Pesticides  

Science.gov (United States)

... inside the house. Pesticides are classed as semi-volatile organic compounds and include a variety of chemicals in various forms. Pesticides are chemicals that are used to kill or control pests which include bacteria, fungi, and other organisms, in addition to insects and ...

391

Using Pesticides Safely. Special Circular 296.  

Science.gov (United States)

The use of pesticides is necessary to aid in the production of food, feed and fiber, and is equally important in the control of home garden and household pests, but correct use is critical in preventing injury to persons, animals, and plants. This circular contains information on State of Pennsylvania and federal pesticide laws; different types of…

Hock, W. K.

392

NATIONAL PESTICIDE INFORMATION RETRIEVAL SYSTEM (NPIRS)  

Science.gov (United States)

The National Pesticide Information Retrieval System (NPIRS) is a collection of pesticide-related databases available through subscription to the Center for Environmental and Regulatory Information Systems, CERIS. The following is a summary of data found in the databases, data sou...

393

RECENT ADVANCES IN PESTICIDE SPRAY APPLICATION TECHNOLOGY  

Science.gov (United States)

Applications of pesticides and other production strategies have ensured adequate and high quality food, fiber, floral and nursery crops. To meet the wide variety of canopy structure characteristics, growing circumstances and marketing requirements, high quality of pesticide transport is essential t...

394

Pesticides exposure in Pakistan: a review.  

Science.gov (United States)

This is the first systematic review of studies done since 1960, and to give an integrated picture of pesticides exposure to humans, animals, plants, waters, soils/sediments, atmosphere etc. in Pakistan. Authors have extracted data from different departments, published literature in research journals and National reports. Although the wide-spread usage of pesticides in Pakistan has controlled the pests, but like other countries, it has started causing environmental problems in the area. In some areas of Punjab and Sindh groundwater has been found contaminated and is constantly being under the process of contamination due to pesticide use. There is considerable evidence that farmers have overused and misused pesticides especially in cotton-growing areas. It is evident from the biological monitoring studies that farmers are at higher risk for acute and chronic health effects associated with pesticides due to occupational exposure. Furthermore, the intensive use of pesticides (higher sprays more than the recommended dose) in cotton areas involves a special risk for the field workers, pickers, and of an unacceptable residue concentration in cottonseed oil and cakes. The authors have also discussed the merits and demerits of different studies. The review will set the future course of action of different studies on pesticide exposure in Pakistan. Data limitations are still the major obstacle towards establishing clear environmental trends in Pakistan. The authors suggest that a reliable monitoring, assessment and reporting procedures shall be implemented in accordance with appropriate environmental policies, laws and regulations in order to minimize the pesticides exposure. PMID:17765971

Tariq, Muhammad Ilyas; Afzal, Shahzad; Hussain, Ishtiaq; Sultana, Nargis

2007-11-01

395

76 FR 16308 - Dichlormid; Pesticide Tolerances  

Science.gov (United States)

...from aggregate exposure to the pesticide chemical residue.'' Consistent...database for dichlormid. Data gaps included several chemistry...all food and non-food use pesticides (40 CFR part 158, subpart...the nature and number of data gaps and qualitative evidence...

2011-03-23

396

Investigation of pesticide degradation in surface waters  

International Nuclear Information System (INIS)

The degradation of organophosphorus and thiocarbamate pesticides was investigated using isotope tracer methods. The hydrolysis (degradation) of ester-type pesticides was studied by radiometric enzyme inhibition method in aqueous medium with 14C as tracer. The hydrolysis of S-ethyl-N,N-dipropylthiocarbamate prerequired the oxidation of the parent compound. (Sz.J.)

397

Biosensors for Pesticide Detection: New Trends  

Directory of Open Access Journals (Sweden)

Full Text Available Due to the large amounts of pesticides commonly used and their impact on health, prompt and accurate pesticide analysis is important. This review gives an overview of recent advances and new trends in biosensors for pesticide detection. Optical, electrochemical and piezoelectric biosensors have been reported based on the detection method. In this review biosensors have been classified according to the immobilized biorecognition element: enzymes, cells, antibodies and, more rarely, DNA. The use of tailor-designed biomolecules, such as aptamers and molecularly imprinted polymers, is reviewed. Artificial Neural Networks, that allow the analysis of pesticide mixtures are also presented. Recent advances in the field of nanomaterials merit special mention. The incorporation of nanomaterials provides highly sensitive sensing devices allowing the efficient detection of pesticides.

Jean-Louis Marty

2012-03-01

398

Toxicity of pesticides on photosynthesis of diatoms  

International Nuclear Information System (INIS)

Pakistan being an agricultural country, a large amount of pesticides are used, including organophosphates and synthetic pyrethroids. These pesticides are released through rivers and other tributeries into the coastal environment, thus posing a contiguous threat to marine organisms. In the present study two species of diatoms Amphora and Navicula were selected for the assessment of impact of organ phosphate and pyrethroid toxicity on these primary producers. The study shows that rate of photosynthesis was inhibited in both Amphora and Navicula species exposed to pesticide. The acute toxicity of pesticide was determined by measuring IC50 of the test organisms. IC50 calculated for diatom species depicts that different pesticides had variable effects on the photosynthesis of microalgae. High sensitivity of marine organisms is alarming as it may have implications on the marine ecosystem and fisheries. The results are also useful in setting control limits for the release of these chemicals in nature. (author)

399

The evaluation of a fast and simple pesticide multiresidue method in various herbs by gas chromatography.  

Science.gov (United States)

In this study two analytical methods, one based on matrix solid phase dispersion (MSPD) and the other on liquid-solid extraction (LSE), coupled with gas chromatography, were evaluated and used to determine the presence of 163 pesticides (6 acaricides, 62 fungicides, 18 herbicides and 77 insecticides) in various herbs. Both methods were optimized considering different parameters (sample to sorbent mass ratio, extracting solvent, sorbents for clean-up step, etc.). The results of these validated sample preparation procedures were compared. Under optimum conditions, the mean recoveries obtained were in the range of 70-119% for MSPD for most pesticides and 70-118% for LSE, but with several exceptions. Precision values, expressed as relative standard deviation (RSD), were ?16% for MSPD and Mentha piperita L.) and thyme (Thymus vulgaris L.). This paper indicates the potential of MSPD for qualitative and quantitative analysis of pesticide residues. This method was therefore validated at three spiking levels (the first ranging from 0.005 to 0.05 mg/kg, the second from 0.05 to 0.5 mg/kg and the third from 0.25 to 2.5 mg/kg) and applied to real samples (n = 15). MSPD proves to be a simple, fast and very useful multiresidue method and can be recommended for routine pesticide monitoring studies in various herbs. PMID:23670401

?ozowicka, Bo?ena; Jankowska, Magdalena; Rutkowska, Ewa; Hrynko, Izabela; Kaczy?ski, Piotr; Mici?ski, Jan

2014-01-01

400