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

Science.gov (United States)

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

Chung, Stephen W C; Chan, Benny T P

2010-07-16

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Effect of soil properties on the persistence of carbamate pesticides.  

Science.gov (United States)

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

Bansal, O P

2009-10-01

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Sensitivity of Acetylcholinesterases from Aphelenchus avenae to Organophosphorous and Carbamate Pesticides  

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

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

1987-01-01

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

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

DEFF Research Database (Denmark)

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

Jensen, A. F.; Petersen, Annette

2003-01-01

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

Directory of Open Access Journals (Sweden)

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

International Nuclear Information System (INIS)

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

2003-12-01

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

Science.gov (United States)

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

10

Retention and selectivity properties of carbamate pesticides on novel polar-embedded stationary phases.  

Science.gov (United States)

This study describes the use of stationary phases with polar functionality suitable for the chemical analysis of carbamates pesticides and comparing with conventional alkyl C8 and C18 phases. The emphasis of this study was to compare the selectivity and retention of the pesticides on different stationary phases, bonded onto 1.7 microm partially porous silica particles under isocratic separation condition. Four stationary phases including: phenylaminopropyl (PAP) phase, bidentate propylurea-C18 (BPUC(18)), C8 and C18, were successfully bonded on the partially porous silica spheres as evidenced by (29)Si and (13)C solid-state NMR analysis. The phenylaminopropyl phase exhibited smaller retentivity and enhanced selectivity compared to the alkyl C8 phase; the analysis time to run separation of the six carbamate pesticides (i.e., methomyl, propoxur, carbofuran, carbaryl, isoprocarb, and promecarb) on the PAP phase was threefold faster than alkyl C8 phase. In a similar manner, the BPUC(18) phase shows similar selectivity to that of the PAP phase, but with longer retentivity; although the BPUC(18) phase is characterized with a lesser degree of retentivity for the carbamate pesticides than the conventional alkyl C18 phase. We propose that pi-pi and weak polar interactions between the carbamate pesticides and the PAP phase dominates the separation mechanism and providing a superior selectivity; faster separation time was also achieved as a result of smaller retentivity. Whereas the C8 and C18 bonded phases exhibits only hydrophobic interactions with the pesticides, leading to larger retentivity. The BPUC(18) phase is shown to interact via polar-polar interactions in addition to hydrophobic interactions with the pesticides, providing similar selectivity with the PAP phase but with larger retentivity. PMID:20496174

Omamogho, Jesse O; Stack, Elaine M; Santalad, Apichai; Srijaranai, Supalax; Glennon, Jeremy D; Yamen, Helen; Albert, Klaus

2010-07-01

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Liquid chromatography with electrochemical detection and coulometric investigations of carbamate and urea pesticides  

Energy Technology Data Exchange (ETDEWEB)

Liquid chromatography with electrochemical detection has been applied for the determination of selected urea pesticides, using a Kelgraf composite electrode. Detection limits of 62-410 ..mu..g/L (1-8 ng) were obtained in a water matrix without sample pretreatment. A flow injection coulometric system based on a reticulated vitreous carbon working electrode was applied for the evaluation of electron transfer stoichiometry (n values) for oxidation of carbamate and urea pesticides. Excellent precision was obtained with relative standard deviations of less than 1% for coulometric n values of nanomole pesticide quantities over a wide range of operating conditions.

von Nehring, Q.G.; Hightower, J.W.; Anderson, J.L.

1986-11-01

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

Science.gov (United States)

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

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

International Nuclear Information System (INIS)

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

2013-08-01

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

Directory of Open Access Journals (Sweden)

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

Spiridon Kintzios

2008-04-01

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Investigation of kinetic interactions between approved oximes and human acetylcholinesterase inhibited by pesticide carbamates.  

Science.gov (United States)

Carbamates are widely used for pest control and act primarily by inhibition of insect and mammalian acetylcholinesterase (AChE). Accidental or intentional uptake of carbamates may result in typical signs and symptoms of cholinergic overstimulation which cannot be discriminated from those of organophosphorus pesticide poisoning. There is an ongoing debate whether standard treatment with atropine and oximes should be recommended for human carbamate poisoning as well, since in vitro and in vivo animal data indicate a deleterious effect of oximes when used in combination with the N-methyl carbamate carbaryl. Therefore, we performed an in vitro kinetic study to investigate the effect of clinically used oximes on carbamoylation and decarbamoylation of human AChE. It became evident that pralidoxime and obidoxime in therapeutic concentrations aggravate the inhibition of AChE by carbaryl and propoxur, with obidoxime being substantially more potent compared to 2-PAM. However, obidoxime had no impact on the decarbamoylation kinetics. Hence, the administration of 2-PAM and especially of obidoxime to severely propoxur and carbaryl poisoned humans cannot be recommended. PMID:23962483

Wille, Timo; Kaltenbach, Lisa; Thiermann, Horst; Worek, Franz

2013-12-01

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

Science.gov (United States)

This study investigated the ability of natural river biofilms from different seasons to degrade the carbamate pesticides methomyl, carbaryl and carbofuran in single and multiple pesticide systems, and the effects of these pesticides on algal and bacterial communities within biofilms. Spring biofilms had the lowest biomass of algae and bacteria but showed the highest methomyl degradation (>99%) and dissipation rates, suggesting that they might contain microorganisms with high methomyl degradation abilities. Degradation of carbofuran (54.1-59.5%) by biofilms in four seasons was similar, but low degradation of carbaryl (0-27.5%) was observed. The coexistence of other pesticides was found to cause certain effects on pesticide degradation and primarily resulted in lower diversity of diatoms and bacteria than when using a single pesticide. The tolerant diatoms and bacteria potentially having the ability to degrade test pesticides were identified. River biofilms could be suitable biomaterials or used to isolate degraders for bioremediating pesticide-contaminated water. PMID:23665845

Tien, Chien-Jung; Lin, Mon-Chu; Chiu, Wan-Hsin; Chen, Colin S

2013-08-01

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

International Nuclear Information System (INIS)

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

2001-07-01

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Adsorption Kinetics of Carbamate Pesticide in Rice Field Soil  

Directory of Open Access Journals (Sweden)

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

Soontree Khuntong

2010-07-01

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

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

International Nuclear Information System (INIS)

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

2000-05-01

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

Science.gov (United States)

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

22

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

Science.gov (United States)

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

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

Science.gov (United States)

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

24

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

25

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

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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 ...

Chowdhury, Md Alamgir Zaman; Banik, Sanjoy; Uddin, Borhan; Moniruzzaman, Mohammed; Karim, Nurul; Gan, Siew Hua

2012-01-01

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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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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 ...

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

2007-01-01

27

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

Science.gov (United States)

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

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

2013-12-15

28

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

DEFF Research Database (Denmark)

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

Jensen, Bodil Hamborg; Petersen, Annette

2009-01-01

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

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

THOMMANDRU RAVEENDRANATH BAB

2014-02-01

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Trace level determinations of carbamate pesticides in surface water by gas chromatography-mass spectrometry after derivatization with 9-xanthydrol.  

Science.gov (United States)

A sensitive and selective gas chromatographic mass spectrometric method, based on derivatization with 9-xanthydrol, has been established for the simultaneous determination of five carbamate pesticides (carbaryl, carbofuran, metolcarb, isoprocarb and ethiofencarb) in surface water. 4-Bromo-3,5-dimethylphenyl-N-methylcarbamate was chosen as the internal standard for analyzing water samples. The derivatization of carbamates was performed directly in water and the reaction conditions (9-xanthydrol of 50.0mM, HCl concentration of 0.05M, reaction for 60min at 60°C) were established through the optimization of various parameters. Under the established conditions, the limits of quantification were in the range of 0.007-0.028?g/L, and the intra- and inter-day relative standard deviation were each less than 15% at concentrations of 0.1, 1.0 and 10?g/L. None of the carbamate pesticides were detected in any of the sixteen surface waters analyzed. PMID:23890551

Yang, Eun-Young; Shin, Ho-Sang

2013-08-30

31

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2012-06-01

32

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

33

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

Science.gov (United States)

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

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

2014-08-15

34

Poisoning of raptors with organophosphorus and carbamate pesticides with emphasis on Canada, U.S. and U.K.  

Science.gov (United States)

We reviewed cases of raptor mortality resulting from cholinesterase-inhibiting pesticides. We compiled records from the U.S., U.K. and Canada for the period 1985-95 (520 incidents) and surveyed the relevant literature to identify the main routes of exposure and those products that led to the greatest number of poisoning cases. A high proportion of cases in the U.K. resulted from abusive uses of pesticides (willful poisoning). The proportion was smaller in North America where problems with labeled uses of pesticides were as frequent as abuse cases. Poisoning resulting from labeled use was possible with a large number of granular pesticides and some seed treatments through secondary poisoning or through the ingestion of contaminated invertebrates, notably earthworms. With the more toxic products, residue levels in freshly-sprayed insects were high enough to cause mortality. The use of organophosphorus products as avicides and for the topical treatment of livestock appeared to be common routes of intoxication. The use of insecticides in dormant oils also gave rise to exposure that can be lethal or which can debilitate birds and increase their vulnerability. A few pesticides of high toxicity were responsible for the bulk of poisoning cases. Based on limited information, raptors appeared to be more sensitive than other bird species to organophosphorus and carbamate pesticides. Some of the more significant risk factors that resulted in raptor poisonings were: insectivory and vermivory; opportunistic taking of debilitated prey; scavenging, especially if the gastrointestinal tracts are consumed; presence in agricultural areas; perceived status as pest species; and flocking or other gregarious behavior at some part of their life cycle. Lethal or sublethal poisoning should always be considered in the diagnosis of dead or debilitated raptors even when another diagnosis (e.g., electrocution, car or building strike) is apparent. Many cases of poisoning are not currently diagnosed as such and, even when diagnosed, the information is often not made available to regulatory authorities. The importance of pesticide intoxications relative to other sources of mortality is highly variable in time and place; on a regional level, the increased mortality of raptors resulting from cholinesterase-inhibiting pesticides can be significant, especially in the case of rare species.

Mineau, P.; Fletcher, M. R.; Glaser, L. C.; Thomas, N. J.; Brassard, C.; Wilson, L. K.; Elliott, J. E.; Lyon, L. A.; Henny, C. J.; Bollinger, T.; Porter, S. L.

1999-01-01

35

Organic-solvent-free extraction method for determination of carbamate and carbamoyloxime pesticides in soil and sediment samples.  

Science.gov (United States)

This study evaluated the usefulness of monochloroacetic acid buffer (MCAAB) for extracting several carbamate/carbamoyloxime pesticides from a silt-loam soil and sediment, and an organic clay soil. The MCAAB extraction method, relative to acetonitrile and methanol extractants, was more accurate and precise for extraction of aldicarb, aldicarb sulfoxide, aldicarb sulfone, oxamyl, methomyl, carbofuran, 3-hydroxy-carbofuran, and propoxur; with recoveries ranging from 78.8% to 121.1%. Recoveries of carbaryl and methiocarb ranged from 0% to 64.1%. The MCCAB extraction method did not perform well for extraction of most compounds from the organic clay soil, with recoveries ranging from 0% to 66.7%. PMID:19771381

Lu, Hai; Lin, Youjian; Wilson, P Chris

2009-11-01

36

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

37

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

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

2010-01-01

38

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

International Nuclear Information System (INIS)

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

2007-01-30

39

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 co...

Dilara Islam Sharif; Mithun Mollick

2013-01-01

40

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

Science.gov (United States)

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

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

2004-12-01

 
 
 
 
41

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

Directory of Open Access Journals (Sweden)

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

Dilara Islam Sharif

2013-01-01

42

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

Science.gov (United States)

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

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

2014-08-15

43

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

International Nuclear Information System (INIS)

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

2001-08-22

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Inhibition of cholinesterases and carboxylesterases of two invertebrate species, Biomphalaria glabrata and Lumbriculus variegatus, by the carbamate pesticide carbaryl.  

Science.gov (United States)

In this study, the effects of sublethal concentrations of the carbamate carbaryl on the cholinesterase (ChE) and carboxylesterase (CES) activities present in the oligochaete Lumbriculus variegatus and in the pigmented Biomphalaria glabrata gastropod were investigated. The results showed that ChE activity from both species was inhibited by in vivo and in vitro exposure to carbaryl, with EC(50) and IC(50) values approximately 20 times lower for the oligochaete than for the gastropod. On the other hand, the recovery process in uncontaminated media was more efficient in oligochaetes than in snails. Thus, in only 2h the oligochaetes showed no inhibition with respect to control values whereas the snails did not reach control values even after 48h of being in pesticide-free water. CES activity was investigated in whole body soft tissue homogenates using three different substrates: p-nitrophenyl butyrate, 1-naphthyl acetate (NA) and 2-NA. In addition, the presence of multiple CES isozymes in L. variegatus and B. glabrata extracts, with activity towards 1- and 2-NA, was confirmed by native polyacrylamide electrophoresis. In both species, the activities measured using the naphthyl substrates were higher than the activity towards p-nitrophenyl butyrate. In addition, B. glabrata showed a higher CES activity than L. variegatus independently of the substrate used. In L. variegatus, in vivo CES activity towards the different substrates was less sensitive to carbaryl inhibition than ChE activity. In contrast, in B. glabrata, CES activity towards p-nitrophenyl butyrate was inhibited at lower insecticide concentrations than ChE. The results of this study contribute to the knowledge of the sensitivity of non-target freshwater invertebrate Type B-esterases towards pesticides. PMID:19879661

Kristoff, Gisela; Guerrero, Noemi R Verrengia; Cochón, Adriana C

2010-01-31

45

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

46

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

Science.gov (United States)

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

47

[Determination of 51 carbamate pesticide residues in vegetables by liquid chromatography-tandem mass spectrometry based on optimization of QuEChERS sample preparation method].  

Science.gov (United States)

The raw extracts of six vegetables (tomato, green bean, shallot, broccoli, ginger and carrot) were analyzed using gas chromatography-mass spectrometry (GC-MS) in full scan mode combined with NIST library search to confirm main matrix compounds. The effects of cleanup and adsorption mechanisms of primary secondary amine (PSA) , octadecylsilane (C18) and PSA + C18 on co-extractives were studied by the weight of evaporation residue for extracts before and after cleanup. The suitability of the two versions of QuEChERS method for sample preparation was evaluated for the extraction of 51 carbamate pesticides in the six vegetables. One of the QuEChERS methods was the original un-buffered method published in 2003, and the other was AOAC Official Method 2007.01 using acetate buffer. As a result, the best effects were obtained from using the combination of C18 and PSA for extract cleanup in vegetables. The acetate-buffered version was suitable for the determination of all pesticides except dioxacarb. Un-buffered QuEChERS method gave satisfactory results for determining dioxacarb. Based on these results, the suitable QuEChERS sample preparation method and liquid chromatography-positive electrospray ionization-tandem mass spectrometry under the optimized conditions were applied to determine the 51 carbamate pesticide residues in six vegetables. The analytes were quantified by matrix-matched standard solution. The recoveries at three levels of 10, 20 and 100 microg/kg spiked in six vegetables ranged from 58.4% to 126% with the relative standard deviations of 3.3%-26%. The limits of quantification (LOQ, S/N > or = 10) were 0.2-10 microg/kg except that the LOQs of cartap and thiofanox were 50 microg/kg. The method is highly efficient, sensitive and suitable for monitoring the 51 carbamate pesticide residues in vegetables. PMID:24669707

Wang, Lianzhu; Zhou, Yu; Huang, Xiaoyan; Wang, Ruilong; Lin, Zixu; Chen, Yong; Wang, Dengfei; Lin, Dejuan; Xu, Dunming

2013-12-01

48

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

The conventional analysis of pesticide residues in analytical commodities, such as tobacco and tobacco products is a labor intensive procedure, since it is necessary to cover a wide range of different chemicals, using a single procedure. Standard analysis methods include extensive sample pretreatment (with solvent extraction and partitioning phases) and determination by GC and HPLC to achieve the necessary selectivity and sensitivity for the different classes of compounds under detection. As ...

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

2008-01-01

49

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

50

Survey of carbamate and organophosphorous pesticide export from a south Florida (U.S.A.) agricultural watershed: implications of sampling frequency on ecological risk estimation.  

Science.gov (United States)

The objectives of the present study were to characterize the presence of selected carbamate and organophosphorous pesticides in Ten Mile Creek (Fort Pierce, FL, U.S.A.) and to evaluate the implications of sampling frequency on ecological risk estimates. Ten Mile Creek originates in a predominately agricultural watershed that is drained by an extensive network of cross-linked canals. Water samples were collected daily or every other day and were analyzed for azinphos-methyl, chlorpyrifos, diazinon, dimethoate, ethion, fenamiphos, malathion, methidathion, carbaryl, carbofuran, 3-hydroxycarbofuran, methiocarb, methomyl, oxamyl, and propoxur. A total of 457 samples were analyzed for the carbamate suite, and a total of 332 samples were analyzed for the organophosphorous suite. Carbaryl was detected in eight samples; half of these detections occurred on four consecutive days (October 26-29, 2001) at concentrations ranging from 0.33 to 0.95 microg/L. Methomyl was detected in samples collected on five consecutive days (March 30-April 3, 2002) at concentrations ranging from 1.0 to 2.2 microg/L. Oxamyl was detected in four samples, three of which occurred on three consecutive days (February 17-19, 2002) at concentrations ranging from 6.2 to 6.8 microg/L. The carbamates propoxur, 3-hydroxycarbofuran, carbofuran, and methiocarb were not detected. Diazinon and ethion were the only organophosphorous pesticides detected. Diazinon was detected at 0.9 and 0.7 microg/L on January 5, 2002, and on January 6, 2002, respectively. Ethion was detected in 18 consecutive samples (August 3-20, 2001). The mean, maximum, minimum, and median detected concentrations were 0.38, 0.61, 0.30, and 0.33 microg/L, respectively. Results indicate that frequent sampling is necessary to characterize the presence of these pesticides in this intensively drained watershed. This conclusion also may apply to similar canalized watersheds. PMID:17089706

Wilsont, P Chris; Foos, Jane Ferguson

2006-11-01

51

Enantiomeric separation of chiral pesticides by high performance liquid chromatography on cellulose tris-3,5-dimethyl carbamate stationary phase under reversed phase conditions.  

Science.gov (United States)

Twenty chiral pesticides were tested, of which seven samples were directly separated by HPLC using cellulose tris-3,5-dimethyl carbamate (CDMPC) chiral stationary phase under RP conditions. The influence of mobile phase composition and column temperatures from 0 degrees C to 40 degrees C on the separations were investigated. The mobile phases were methanol/water or ACN/water at a flow rate of 0.8 mL/min with UV detection at 230 or 210 nm. Epoxiconazole, terallethrin, benalaxyl, and diclofopmethyl were observed to obtain the baseline separation under suitable conditions and other pesticides pyriproxyfen, lactofen, and quizalofop-ethyl were separated partially. The retention factors (k) and selectivity factor (alpha) for the enantiomers of most investigated pesticides decreased upon increasing the temperature except for the selectivity factors (alpha) of pyriproxyfen in methanol/water. The ln alpha - 1/T plots for racemic chiral pesticides were linear at the range of 0-40 except for that of pyriproxyfen enantiomers in methanol/water and the chiral separations were controlled by enthalpy. Better separations were not always at low temperature. The elution orders of the eluting enantiomers were determined by a circular dichroism (CD) detector. PMID:17396588

Tian, Qin; Lv, Chunguang; Wang, Peng; Ren, Liping; Qiu, Jing; Li, Li; Zhou, Zhiqiang

2007-02-01

52

A solid-phase microextraction-gas chromatographic approach combined with triple quadrupole mass spectrometry for the assay of carbamate pesticides in water samples.  

Science.gov (United States)

A simple and sensitive method was developed for the quantification of five carbamate pesticides in water samples using solid phase microextraction (SPME) combined with gas chromatography-triple quadrupole mass spectrometry (GC-QqQ-MS). The performance of five SPME fibers was tested in univariate mode whereas the other variables affecting the efficiency of SPME analysis were optimized by the multivariate approach of design of experiment (DoE) and, in particular, a central composite design (CCD) was applied. The optimum working conditions in terms of response values were achieved by performing analysis with polydimethylsiloxane/divinylbenzene (PDMS/DVB) fiber in immersion mode for 45min at room temperature with addition of NaCl (10%). The multivariate chemometric approach was also used to explore the chromatographic behavior of the carbamates and to evaluate the importance of each variable investigated. An overall appraisement of results shows that the factor which gave a statistically significant effect on the response was only the injection temperature. Identification and quantification of carbamates was performed by using a gas chromatography-triple quadrupole mass spectrometry (GC-QqQ-MS) system in multiple reaction monitoring (MRM) acquisition. Since the choice of internal standard represented a crucial step in the development of method to achieve good reproducibility and robustness for the entire analytical protocol, three compounds (2,3,5-trimethacarb, 4-bromo-3,5-dimethylphenyl-n-methylcarbamate (BDMC) and carbaryl-d7) were evaluated as internal standards. Both precision and accuracy of the proposed protocol tested at concentration of 0.08, 5 and 3 ?g l?¹ offered values ranging from 70.8% and 115.7% (except for carbaryl at 3 ?g l?¹) and from 1.0% and 9.0% for accuracy and precision, respectively. Moreover, LOD and LOQ values ranging from 0.04 to 1.7 ng l?¹ and from 0.64 to 2.9 ng l?¹, respectively, can be considered very satisfactory. PMID:22907043

Cavaliere, Brunella; Monteleone, Marcello; Naccarato, Attilio; Sindona, Giovanni; Tagarelli, Antonio

2012-09-28

53

Characterization of acetylcholinesterase from the brain of the Amazonian tambaqui (Colossoma macropomum) and in vitro effect of organophosphorus and carbamate pesticides.  

Science.gov (United States)

In the present study, acetylcholinesterase (AChE) from the brain of the Amazonian fish tambaqui (Colossoma macropomum) was partially characterized and its activity was assayed in the presence of five organophosphates (dichlorvos, diazinon, chlorpyrifos, and tetraethyl pyrophosphate [TEPP]) and two carbamates (carbaryl and carbofuran) insecticides. Optimal pH and temperature were 7.0 to 8.0 and 45°C, respectively. The enzyme retained approximately 70% of activity after incubation at 50°C for 30 min. The insecticide concentration capable of inhibiting half of the enzyme activity (IC50) for dichlorvos, chlorpyrifos, and TEPP were calculated as 0.04?µmol/L, 7.6?µmol/L, and 3.7?µmol/L, respectively. Diazinon and temephos did not inhibit the enzyme. The IC50 values for carbaryl and carbofuran were estimated as 33.8?µmol/L and 0.92?µmol/L, respectively. These results suggest that AChE from the juvenile C. macropomum brain could be used as an alternative biocomponent of organophosphorus and carbamate biosensors in routine pesticide screening in the environment. PMID:20872688

Assis, Caio Rodrigo Dias; Castro, Patrícia Fernandes; Amaral, Ian Porto Gurgel; Carvalho, Elba Verônica Matoso Maciel; Carvalho, Luiz Bezerra; Bezerra, Ranilson Souza

2010-10-01

54

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2010-06-25

55

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

Science.gov (United States)

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

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

2012-11-21

56

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

Science.gov (United States)

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

57

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

International Nuclear Information System (INIS)

This study describes the implementation and validation of a multiresidue methodology for the determination of organochlorine, organophosphorus and pyrethroids pesticides in green coffee. Pesticides residues were extracted from green samples with an acetone-water (2:1) mixture followed by ethyl acetate cyclohexane (1:1) partitioning. The clean up steps include gel permeation chromatography and mini column chromatography using silica gel. Final determination was carried out by high-resolution gas chromatography with a pulsed split less injection mode and simultaneous detection by ?-ECD and NPD coupled in parallel. The methodology is specific, selective precise and accurate. Recoveries of majority of pesticides from spiked samples range from 70 to 110% at fortification levels of 0.038 mg/kg-1.536 mg/kg with limit of quantitation between 0.011 mg/kg and 0.100 mg/kg

2005-01-01

58

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

International Nuclear Information System (INIS)

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

2009-10-06

59

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

Scientific Electronic Library Online (English)

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

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

60

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

Science.gov (United States)

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

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

2011-09-01

 
 
 
 
61

(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...

62

Pesticide toxicosis in the horse.  

Science.gov (United States)

Toxicosis from pesticides rarely occurs in horses and is usually the result of inappropriate pesticide use or handling by humans. Organophosphorus and carbamate insecticides inhibit acetylcholinesterase and are the insecticide class most frequently associated with toxicosis in domestic animals. Metaldehyde is a molluscicide, and zinc phosphide is a rodenticide, both of which have caused toxicosis in horses. All three of these pesticides affect the nervous system of horses and can be fatal if not treated promptly. PMID:11780282

Plumlee, K H

2001-12-01

63

Validation of a solid-phase microextraction method for the determination of organophosphorus pesticides in fruits and fruit juice.  

Science.gov (United States)

A method for the determination of organophosphorus pesticides (diazinon, fenitrothion, fenthion, quinalphos, triazophos, phosalon and pyrazophos) in fruit (pears) and fruit juice samples was developed and validated. The samples were diluted with water, extracted by solid-phase microextraction (SPME) and analysed by gas chromatography (GC) using a flame photometric detector in phosphorous mode. Limits of detection of the method for fruit and fruit juice matrices were below 2 micrograms/kg for all pesticides. Relative standard deviations for triplicate analyses of samples fortified at 25 micrograms/kg of each pesticide were not higher than 8.7%. Recovery tests were performed for concentrations between 25 and 250 micrograms/kg. Mean recoveries for each pesticide were all above 75.9% and below 102.6% for juice, and between 70 and 99% for fruit except for pyrazophos in the fruit sample (with mean recovery of 53%). Therefore, the proposed method is applicable in the analysis of pesticides in fruit matrices and the use of the method in routine analysis of pesticide residues is discussed. PMID:10074697

Simplício, A L; Boas, L V

1999-02-12

64

Carbamate deposit control additives  

Energy Technology Data Exchange (ETDEWEB)

Deposit control additives for internal combustion engines are provided which maintain cleanliness of intake systems without contributing to combustion chamber deposits. The additives are poly(oxyalkylene) carbamates comprising a hydrocarbyloxyterminated poly(Oxyalkylene) chain of 2-5 carbon oxyalkylene units bonded through an oxycarbonyl group to a nitrogen atom of ethylenediamine.

Honnen, L.R.; Lewis, R.A.

1980-11-25

65

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

2005-01-01

66

ACTIVE CASPASE-3 DETECTION IN CARBAMATE BENDIOCARB TREATED RABBIT LIVER  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Increasing use of pesticides all over the world makes it necessary to reveal the toxic risk in populations of non-targeted organisms. Bendiocarb is a carbamate pesticide which is used against a variety of insects, and the liver has an important role in its process of detoxication and excretion. In our experiment were used 56 adult rabbits which were divided into four groups (control, days 10, 20, 30 of administration) and all experimental rabbits received bendiocarb per os in a dose 5 mg/kg b...

2013-01-01

67

Simulation of carbonfuran and hexazinone movement into groundwater in central Florida using PRZM (Pesticide) Root Zone Model)  

Energy Technology Data Exchange (ETDEWEB)

PRZM (Pesticide Root Zone Model) was developed to predict movement of pesticides within the plant root zone of soils and below to a depth of 7 m. The model, developed for surface-applied or soil incorporated pesticides, consists of 1) a hydrology component for calculating removal of precipitation by runoff, evapotranspiration, and crop interception, and 2) a chemical transport component for calculating uptake by plants, volatolization, decay, leaching, dispersion, concentration in runoff, retardation, soil solution and solid phase concentrations. Simulations were run for carbofuran, a moderately soluble, highly toxic carbamate insecticide, and hexazinone, a highly soluble, low toxicity triazine herbicide. Simulations and validation field experiments were done on forest sites with deep Typic Quartzipsamment soils overlying the Floridan Aquifer in Central Florida. Implications on use of predicting groundwater contamination and the risks of pesticide use are discussed.

Neary, D.G.; Bush, P.B.; Smith, C.S.; Carsel, R.F.; Phillips, M.J.

1985-01-01

68

TERMINAL RESIDUES OF CARBAMATE INSECTICIDES  

Science.gov (United States)

Three reviews of carbamate metabolism have appeared recently. One general review covered the degradation in soil and by soil microorganisms and the third review addressed the specific topic of derivatized carbamate insecticides. Many of the points noted in these reviews have been...

69

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.

2011-01-01

70

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

Science.gov (United States)

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

71

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

Science.gov (United States)

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

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

2009-02-01

72

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

2001-01-01

73

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

74

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.

75

Pesticides and inner-city children: exposures, risks, and prevention.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Six million children live in poverty in America's inner cities. These children are at high risk of exposure to pesticides that are used extensively in urban schools, homes, and day-care centers for control of roaches, rats, and other vermin. The organophosphate insecticide chlorpyrifos and certain pyrethroids are the registered pesticides most heavily applied in cities. Illegal street pesticides are also in use, including tres pasitos (a carbamate), tiza china, and methyl parathion. In New Yo...

Landrigan, P. J.; Claudio, L.; Markowitz, S. B.; Berkowitz, G. S.; Brenner, B. L.; Romero, H.; Wetmur, J. G.; Matte, T. D.; Gore, A. C.; Godbold, J. H.; Wolff, M. S.

1999-01-01

76

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 SciELO Brazil | Language: English Abstract in portuguese 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.

77

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)

2010-03-01

78

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

Scientific Electronic Library Online (English)

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

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

79

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

80

The toxicologic effects of the carbamate insecticide aldicarb in mammals: a review.  

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Aldicarb, 2-methyl-2-(methylthio)propionaldehyde-O-methylcarbamoyloxime, is an oxime carbamate insecticide manufactured by the Union Carbide Corporation and sold under the trade name Temik. It is a soil-applied systemic pesticide used against certain insects, mites, and nematodes, and is applied below the soil surface for absorption by plant roots. It is generally applied to the soil in the form of 5, 10, or 15% granules, and soil moisture is essential for the release of the toxicant. Uptake ...

1987-01-01

 
 
 
 
81

Validation of a flow-through sampler for pesticides and polybrominated diphenyl ethers in air  

Science.gov (United States)

At locations without access to the electrical grid, a flow-through sampler (FTS) collects large volumes of air for the analysis of semi-volatile organic compounds (SVOCs). To test its performance under field conditions, an FTS and a traditional pumped high volume air sampler, both using polyurethane foam (PUF) as sampling medium, were co-deployed at the campus of the University of Toronto Scarborough from August 2006 to June 2007. Polybrominated diphenyl ethers (PBDEs) and various pesticides were quantified in the samples taken by both samplers to test the FTS's applicability to relatively non-volatile and slightly polar SVOCs. Air concentrations in samples taken with the FTS over five 2-week periods compare favourably with the average of the concentrations in several 24-h active high volume samples taken during the same period. In particular, time trends, temperature dependence relationships, and isomer ratios show a reasonable agreement between the two sampling techniques. An empirical linear solvation energy relationship for predicting the apparent theoretical plate number of the PUF assembly used in the FTS illustrates the effect of chemical properties, as well as temperature and wind speed, on sampling efficiency. In the absence of electrical power, the FTS can collect SVOCs from large air volumes as reliably and quantitatively as traditional HiVol samplers, although without separating gas and particle phase.

Xiao, Hang; Hung, Hayley; Lei, Ying Duan; Wania, Frank

82

Acetylcholinesterase inhibition as an indicator of organophosphate and carbamate poisoning in Kenyan agricultural workers.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Acetylcholinesterase inhibition was determined for 666 Kenyan agricultural workers; 390 (58.6%) mainly pesticide applicators exposed to organophosphate and carbamate pesticides and 276 (41.4%) unexposed controls from four rural agricultural areas during 1993 and 1994. Baseline levels were depressed in the exposed group (6.1 /- 0.84; 4.09 /- 0.84) but not in the unexposed group (5.83 /- 0.91; 5.60 /- 0.87). Acetylcholinesterase inhibition was found in all exposed individuals and led, on av...

Ohayo-mitoko, G. J. A.; Heederik, D.; Kromhout, H.; Omondi, B. E. O.; Boleij, J. S. M.

1997-01-01

83

Biodegradation of pesticides. (Latest citations from the Biobusiness data base). Published Search  

Energy Technology Data Exchange (ETDEWEB)

The bibliography contains citations concerning the biological degradation of pesticides. Pesticides such as malathion, parathion and DDT, organophosphates and carbamates, herbicides, fungicides, and rodenticides are examined. Coverage includes the isolation of enzymes specifically able to degrade pesticides, field studies of natural degradation and migration of pesticides, and test tube examination of microbial organisms with the ability to digest pesticides. Degradation products, effects of available nutrients on microbial degradation, and pesticide resistance in natural ecosystems are also discussed. (Contains a minimum of 190 citations and includes a subject term index and title list.)

1992-05-01

84

Validation of a fast and easy method for the determination of residues from 229 pesticides in fruits and vegetables using gas and liquid chromatography and mass spectrometric detection.  

Science.gov (United States)

Validation experiments were conducted of a simple, fast, and inexpensive method for the determination of 229 pesticides fortified at 10-100 ng/g in lettuce and orange matrixes. The method is known as the quick, easy, cheap, effective, rugged, and safe (QuEChERS) method for pesticide residues in foods. The procedure involved the extraction of a 15 g sample with 15 mL acetonitrile, followed by a liquid-liquid partitioning step performed by adding 6 g anhydrous MgSO4 plus 1.5 g NaCl. After centrifugation, the extract was decanted into a tube containing 300 mg primary secondary amine (PSA) sorbent plus 1.8 g anhydrous MgSO4, which constituted a cleanup procedure called dispersive solid-phase extraction (dispersive SPE). After a second shaking and centrifugation step, the acetonitrile extract was transferred to autosampler vials for concurrent analysis by gas chromatography/mass spectrometry with an ion trap instrument and liquid chromatography/tandem mass spectrometry with a triple quadrupole instrument using electrospray ionization. Each analytical method was designed to analyze 144 pesticides, with 59 targeted by both instruments. Recoveries for all but 11 of the analytes in at least one of the matrixes were between 70-120% (90-110% for 206 pesticides), and repeatabilities typically <10% were achieved for a wide range of fortified pesticides, including methamidophos, spinosad, imidacloprid, and imazalil. Dispersive SPE with PSA retained carboxylic acids (e.g., daminozide), and <50% recoveries were obtained for asulam, pyridate, dicofol, thiram, and chlorothalonil. Many actual samples and proficiency test samples were analyzed by the method, and the results compared favorably with those from traditional methods. PMID:15859089

Lehotay, Steven J; de Kok, André; Hiemstra, Maurice; Van Bodegraven, Peter

2005-01-01

85

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

86

Rapid multimethod for verification and determination of toxic pesticides in whole blood by means of capillary GC-MS.  

Science.gov (United States)

A rapid and single multimethod was developed to determine substances of different pesticide classes in whole blood in the event of acute human intoxications, as required by EU Commission Directive 96/46. The method was validated by an in-house and an independent laboratory validation. Whole blood is hemolyzed and then deproteinized. After extraction of the supernatant, blood levels are determined by gas chromatography-mass spectrometry. The method, which can be performed within 120 min, covers 15 active substances (8 organophosphate pesticides, 2 carbamates, 3 pyrethroids, 1 azole, and 1 organochlorine pesticide) classified as toxic or very toxic. These compounds can be identified down to concentrations between 100 and 1000 ng/mL by comparison of their mass spectra to those in a commercial pesticide mass spectra library. Using the standard addition method, they can be quantitated down to concentrations between 30 and 200 ng/mL. These limits of quantitation are considered to be sufficient in comparison to respective LD50 values. PMID:10926361

Frenzel, T; Sochor, H; Speer, K; Uihlein, M

2000-01-01

87

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

88

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

89

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

Directory of Open Access Journals (Sweden)

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

Sonia C. N. Queiroz

2012-01-01

90

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

Science.gov (United States)

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

91

Neurotoxicity of pesticides to salmon: Physiology to ethology  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Pesticides routinely found in the environment can adversely affect neurological systems of salmon. The major focus of the studies presented here is on the impairment of the relatively exposed olfactory sensory neurons (OSNs), since their functionality is critical to several indispensable behaviours. The responses of OSNs to various behaviourally-relevant odorants were impaired following exposure to several pesticide classes, including triazine (e.g. atrazine), carbamate (e.g. IPBC), organopho...

Tierney, Keith Bryan

2007-01-01

92

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

2002-01-01

93

Role of individual susceptibility in risk assessment of pesticides  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 ...

1999-01-01

94

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

In this study, the knowledge, attitudes and practices regarding pesticide use and the levels of exposure of farmers and residents to organophosphorous and/or carbamates pesticides were evaluated in two rural settings in Brazil. A questionnaire was completed by 112 farm workers aged ?18 years. Almost all farmers acknowledged that pesticides were potentially harmful to their health (87.5%); however, over half rarely (48.2%) or never (7.2%) used personal protective devices (PPDs). An associati...

Oliveira Pasiani, Juliana; Torres, Priscila; Roniery Silva, Jucie?; Zago Diniz, Bruno; Dutra Caldas, Eloisa

2012-01-01

95

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

The Densu River Basin constitutes one of the largest agricultural areas in Ghana. The practice of using pesticides such as organochlorines, organophosphates, carbamates, pyrethroids and several others in agriculture and public health programs has raised concerns about potentially adverse effects on human health and the environment. In this study, a field survey was conducted to assess farmers’ knowledge of safe handling and use of pesticides. Residues of pesticides in fish samples as well a...

Fianko, J. R.; Donkor, A.; Lowor, S. T.; Yeboah, P. O.; Glover, E. T.; Adom, T.; Faanu, A.

2011-01-01

96

Effect of pesticides carbaryl and phorate on serum cholesterol level in fish, Clarias batrachus (Linn).  

Science.gov (United States)

Freshwater edible catfish Clarias batrachus (Linn.) was treated with sublethal concentration of two different groups of pesticides- carbaryl, a carbamate and phorate, an organophosphate for 24 ,72 ,120 and 168 h. The disorders of lipid metabolism were observed in serum. Cholesterol levels in the serum decreased significantly throughout the exposure period with both the pesticides. These results indicate one significant manifestation of the toxic response from the fish under the stress of pesticide exposure. PMID:12017268

Jyothi, B; Narayan, G

2001-07-01

97

Electrochemical study of some insecticides deriving from carbamates in aprotic media  

International Nuclear Information System (INIS)

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

2009-12-19

98

Fluorimetric Determination of Carbamate Pesticides in Host-Guest Complexes  

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

Alicia Viviana Veglia

2000-01-01

99

Fluorimetric Determination of Carbamate Pesticides in Host-Guest Complexes  

Directory of Open Access Journals (Sweden)

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

Alicia Viviana Veglia

2000-03-01

100

Adsorption Kinetics of Carbamate Pesticide in Rice Field Soil  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Ultrasonic extraction (75.55%) with petroleum ether:acetone (1:1, v/v) was employed for extraction of carbofuran in rice field soil. The amounts of carbofuran were determined by reverse phase HPLC. The analytical method provided high precision and accuracy with the relative error of 0.47%. The percentage of recoveries varied from 84% to 77% in the con¬centration ranges of 10–40 mg/L of spiked soil samples. The carbofuran residues in the rice field soil significantly decreased year by year ...

2010-01-01

 
 
 
 
101

Measurement of Pyrethroid, Organophosphorus, and Carbamate Insecticides in Human Plasma using Isotope Dilution Gas Chromatography-High Resolution Mass Spectrometry  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We have developed a gas chromatography-high resolution mass spectrometry method for measuring pyrethroid, organophosphorus, carbamate and fipronil pesticides and the synergist piperonyl butoxide in human plasma. Plasma samples were extracted using solid phase extraction and were then concentrated for injection and analysis using isotope dilution gas chromatography-high resolution mass spectrometry. The limits of detection ranged from 10 to 158 pg/mL with relative recoveries at concentrations ...

Pe?rez, Jose? J.; Williams, Megan K.; Weerasekera, Gayanga; Smith, Kimberly; Whyatt, Robin M.; Needham, Larry L.; Barr, Dana Boyd

2010-01-01

102

Study for detecting pesticides in water by the use of acetylcholinesterase in human red blood cells; Hito kekkyu acetylcholinesterase wo mochiita noyaku kenshutsuho ni kansuru kisoteki kento  

Energy Technology Data Exchange (ETDEWEB)

We investigated the possibility of a method to monitor pesticides in water by assaying effects of organophosphorus and carbamate pesticides upon acetylcholinesterase (AChE) activity. The procedure is very simple as follows; the human red blood cell suspension was added to sample water and then AChE activity was determined by autoanalyzer. Using this method, we assayed 33 kinds of organophosphorus pesticide, 8 kinds of its oxon, and 12 kinds of carbamate pesticide. Nineteen out of the 33 organophosphorus pesticides, 7 out of the 8 oxons of organophosphorus pesticide, and all of the 12 carbamate pesticides tested were detected at the concentration of less than 1mg{center_dot}l{sup -1}. Even at the concentration 100ng{center_dot}l{sup -1}, EDDP, Benfracarb, Chlorpyrifos oxon, Isoxathion oxon and Diazinon oxon were detected. In addition, 13 pesticides were detected at the concentration of 100ng{center_dot}l{sup -1} in the water containing 1mg{center_dot}l{sup -1} chlorine, which is equivalent to the chlorine level in water disinfection process. This analytical method, although the detectable concentration levels are varied widely according to the type of pesticides, is capable of detecting many of organophosphorus and carbamate pesticides in water. 12 refs., 1 fig., 5 tabs.

Makihata, N.; Kawamoto, T.; Teranishi, K. [Hyogo Prefectural Institute of Public Health, Kobe (Japan)

1997-11-15

103

Assessment of Pesticide Residues in Honey Samples from Portugal and Spain  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Fifty samples of honey collected from local markets of Portugal and Spain during year 2002 were analyzed for 42 organochlorine, carbamate, and organophosphorus pesticide residues. An analytical procedure based on solid-phase extraction with octadecyl sorbent followed by gas chromatography?mass spectrometry (GC?MS), for organochlorines, and by liquid chromatography?atmospheric pressure chemical ionization-mass spectrometry (LC?APCI-MS), for organophosphorus and carbamates, has been dev...

2003-01-01

104

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

Science.gov (United States)

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

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

2014-08-01

105

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

Science.gov (United States)

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

106

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

Science.gov (United States)

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

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

2003-01-01

107

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 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

2005-09-01

108

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

109

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

Mol, Hans G. J.; Rooseboom, Astrid; Dam, Ruud; Roding, Marleen; Arondeus, Karin; Sunarto, Suryati

2007-01-01

110

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

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

2007-01-01

111

Reproductive disorders associated with pesticide exposure.  

Science.gov (United States)

Exposure of men or women to certain pesticides at sufficient doses may increase the risk for sperm abnormalities, decreased fertility, a deficit of male children, spontaneous abortion, birth defects or fetal growth retardation. Pesticides from workplace or environmental exposures enter breast milk. Certain pesticides have been linked to developmental neurobehavioral problems, altered function of immune cells and possibly childhood leukemia. In well-designed epidemiologic studies, adverse reproductive or developmental effects have been associated with mixed pesticide exposure in occupational settings, particularly when personal protective equipment is not used. Every class of pesticides has at least one agent capable of affecting a reproductive or developmental endpoint in laboratory animals or people, including organophosphates, carbamates, pyrethroids, herbicides, fungicides, fumigants and especially organochlorines. Many of the most toxic pesticides have been banned or restricted in developed nations, but high exposures to these agents are still occurring in the most impoverished countries around the globe. Protective clothing, masks and gloves are more difficult to tolerate in hot, humid weather, or may be unavailable or unaffordable. Counseling patients who are concerned about reproductive and developmental effects of pesticides often involves helping them assess their exposure levels, weigh risks and benefits, and adopt practices to reduce or eliminate their absorbed dose. Patients may not realize that by the first prenatal care visit, most disruptions of organogenesis have already occurred. Planning ahead provides the best chance of lowering risk from pesticides and remediating other risk factors before conception. PMID:18032334

Frazier, Linda M

2007-01-01

112

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  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

113

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

114

Oxidative carbonylation of amines to carbamates  

Energy Technology Data Exchange (ETDEWEB)

Within the last several years, new technologies have appeared to replace phosgene for isocyanate manufacture. These include carbamate chemistries based upon dialkyl carbonate, reductive carbonylation of nitroaromatics, and oxidative carbonylation of amines. The carbamate ester can be handled safely and is reversibly cleaved to the isocyanate. The technology described here involves the preparation of both aliphatic and aromatic carbamates from an amine, alcohol, CO, oxidant, and a non-corrosive catalyst. The catalyst precursor is Pd(OAc){sub 2} and the oxidants are copper carboxylates or copper carboxylates and molecular oxygen. The latter represents a one-step carbamate synthesis with high catalyst activity, nearly quantitative conversions and alcohol selectivities greater than 90%. Operating temperatures and pressures are 80-110{degree}C and less than 500 psi, respectively. Experiments designed to probe the mechanism will be presented along with a discussion of novel (Cu(O{sub 2}CR){sub 2}){sub 2}R'NH{sub 2} complexes.

Waller, F.J.

1987-04-01

115

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)

2008-01-01

116

Divergent effects of postmortem ambient temperature on organophosphorus- and carbamate-inhibited brain cholinesterase activity in birds  

Science.gov (United States)

Time- and temperature-dependent postmortem changes in inhibited brain cholinesterase (ChE) activity may confound diagnosis of field poisoning of wildlife by anticholinesterase pesticide. Carbamate-inhibited ChE activity may return to normal within 1 to 2 days of exposure of intact carcass to moderate ambient temperature (18-32C). Organophosphorus-inhibited ChE activity becomes more depressed over the same time. Uninhibited ChE activity was resilient to above freezing temperature to 32C for 1 day and 25C for 3 days. Carbamate- and organophosphorus-inhibited ChE can be separated by incubation of homogenate for 1 hour at physiological temperatures; carbamylated ChE can be readily reactivated while phosphorylated ChE cannot.

Hill, E.F.

1989-01-01

117

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

Science.gov (United States)

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

Dabrowski, James Michael; Balderacchi, Matteo

2013-11-01

118

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

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

2013-01-01

119

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

Considering acute and chronic toxicity effects on human and animal health caused by pesticide residues in food, this study aimed to analyze organophosphorate (OP) and carbamate (CB) in feedstuff and water destined for dairy cattle, as well as in the milk produced by these animals, through gas chromatography (GC). In the Agreste region of Pernambuco, Brazil, 30 raw milk samples and all components of the animals' diet were collected from several farms. Out of the 30 milk of milk analyzed, six (...

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

2011-01-01

120

Biomarkers of Sensitivity and Exposure in Washington State Pesticide Handlers  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

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

2010-01-01

 
 
 
 
121

Vinyl carbamate epoxide, a major strong electrophilic, mutagenic and carcinogenic metabolite of vinyl carbamate and ethyl carbamate (urethane).  

Science.gov (United States)

Vinyl carbamate epoxide (VCO) was found to possess strong electrophilic, mutagenic and carcinogenic activities. It reacted with water at 37 degrees C and pH 7.4 (phosphate buffer) to form glycolaldehyde and several related reducing compounds; none of these products were mutagenic for Salmonella typhimurium TA1535. Under these conditions VCO had a half-life (determined chemically and mutagenically) of approximately 10.5 min. This half-life was progressively lowered by increasing concentrations of chloride ion (liver, serum and isotonic levels). This ion reacted with VCO to form chloroacetaldehyde. VCO also reacted with other nucleophiles such as glutathione, DNA and its constituent guanine and adenine bases. The purine adducts formed by VCO in DNA in vitro and in vivo were released by weak acid treatment and consisted of 7-(2'-oxoethyl)guanine and N2,3-ethenoguanine as major products with 1,N6-ethenoadenine as a minor product. VCO was a strong direct mutagen in Salmonella typhimurium TA1535 and TA100 but was only weakly active in the TA98 mutant. VCO was a stronger initiator of carcinogenesis in the skin of CD-1 mice and in the liver of infant male B6C3F1 mice than its metabolic precursors vinyl carbamate (VC) and ethyl carbamate (EC). Unlike VC and EC, VCO was a strong complete carcinogen in the skin of CD-1 mice and induced papillomas and carcinomas following repetitive administration of sub-ulcerogenic doses. VCO also exhibited some carcinogenic activity in the lungs of mice and in the s.c. and mammary tissue of female Sprague-Dawley rats. These data and those from other recent studies support the conclusion that VCO is a major strong electrophilic, mutagenic and carcinogenic metabolite of EC and VC in the mouse. PMID:8453720

Park, K K; Liem, A; Stewart, B C; Miller, J A

1993-03-01

122

Applying pesticides  

Science.gov (United States)

Fertilizer is one way to provide crops with the nutrients they need. Pesticides can also be applied to crops to keep them healthy and free of insects. However, applying too much fertilizer or pesticide protection could harm the environment and organisms.

Scott Bauer (USDA-ARS;Yakima Agricultural Research Laboratory)

2006-05-23

123

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

Science.gov (United States)

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

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

2008-03-01

124

Study of Serum Cholinesterase levels in fish Clarias batrachus (Linn.) exposed to pesticides carbaryl and phorate.  

Science.gov (United States)

Study of the Serum Cholinesterase levels (SchE) in the freshwater catfish Clarias batrachus when exposed to sub lethal dose of pesticides phorate and carbamate, was attempted in this paper. SchE levels decreased in the fish exposed to both the pesticides, the depletion being more pronounced with phorate. These results can be due to impairment of nervous system, liver damage as well as myocardial infarction. Similar findings were not only reported in experimental organisms but also found in human beings working in agricultural fields and pesticide manufacturing plants. Hence it is imperative that suitable occupational health and preventive measures need to be undertaken. PMID:16649625

Jyothi, B; Narayan, G

2004-10-01

125

Computational evidence for the reactivation process of human acetylcholinesterase inhibited by carbamates.  

Science.gov (United States)

Acetylcholinesterase (AChE) is responsible for hydrolysis of acetylcholine (ACh), a function, which if disrupted, leads to cholinergic syndrome. Carbamates (CB) and organophosphorus compounds (OP) are AChE inhibitors, toxic and capable of causing severe poisoning or death to exposed individuals. The AChE reactivation is considered the main function of the oximes. In case of poisoning by CB, there is no consistent data in the literature for an oxime reactivation mechanism. In this work, we evaluated the affinity and reactivity of oximes with activity already reported against AChE inhibited by the OP chemical warfare agent ciclosarin, with MmAChE and HsAChE active sites inhibited by the CB pesticide carbofuran. Thus, our theoretical data indicate that HLO-7, BI-6 and K005 compounds may be promising reactivators of AChE inhibited by carbofuran. PMID:24344993

Matos, Karina Silvia; da Cunha, Elaine F F; Abagyan, Ruben; Ramalho, Teodorico C

2014-01-01

126

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

127

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

128

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

Science.gov (United States)

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

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

2014-08-15

129

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

Science.gov (United States)

Acetylcholinesterase (AChE) is a proven target for control of the malaria mosquito (Anopheles gambiae). Unfortunately, a single amino acid mutation (G119S) in An. gambiae AChE-1 (AgAChE) confers resistance to the AChE inhibitors currently approved by the World Health Organization for indoor residual spraying. In this report, we describe several carbamate inhibitors that potently inhibit G119S AgAChE and that are contact-toxic to carbamate-resistant An. gambiae. PCR-RFLP analysis was used to confirm that carbamate-susceptible G3 and carbamate-resistant Akron strains of An. gambiae carry wild-type (WT) and G119S AChE, respectively. G119S AgAChE was expressed and purified for the first time, and was shown to have only 3% of the turnover number (kcat) of the WT enzyme. Twelve carbamates were then assayed for inhibition of these enzymes. High resistance ratios (>2,500-fold) were observed for carbamates bearing a benzene ring core, consistent with the carbamate-resistant phenotype of the G119S enzyme. Interestingly, resistance ratios for two oxime methylcarbamates, and for five pyrazol-4-yl methylcarbamates were found to be much lower (4- to 65-fold). The toxicities of these carbamates to live G3 and Akron strain An. gambiae were determined. As expected from the enzyme resistance ratios, carbamates bearing a benzene ring core showed low toxicity to Akron strain An. gambiae (LC50>5,000 ?g/mL). However, one oxime methylcarbamate (aldicarb) and five pyrazol-4-yl methylcarbamates (4a–e) showed good to excellent toxicity to the Akron strain (LC50?=?32–650 ?g/mL). These results suggest that appropriately functionalized “small-core” carbamates could function as a resistance-breaking anticholinesterase insecticides against the malaria mosquito.

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

2012-01-01

130

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  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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, Hans G. J.; Zomer, Paul; Koning, Maarten

2012-01-01

131

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  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 negatives...

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

2012-01-01

132

Single solid phase extraction method for the simultaneous analysis of polar and non-polar pesticides in urine samples by gas chromatography and ultra high pressure liquid chromatography coupled to tandem mass spectrometry.  

Science.gov (United States)

A new multiresidue method has been developed and validated for the simultaneous extraction of more than two hundred pesticides, including non-polar and polar pesticides (carbamates, organochlorine, organophosphorous, pyrethroids, herbicides and insecticides) in urine at trace levels by gas and ultra high pressure liquid chromatography coupled to ion trap and triple quadrupole mass spectrometry, respectively (GC-IT-MS/MS, UHPLC-QqQ-MS/MS). Non-polar and polar pesticides were simultaneously extracted from urine samples by a simple and fast solid phase extraction (SPE) procedure using C(18) cartridges as sorbent, and dichloromethane as elution solvent. Recovery was in the range of 60-120%. Precision values expressed as relative standard deviation (RSD) were lower than 25%. Identification and confirmation of the compounds were performed by the use of retention time windows, comparison of spectra (GC-amenable compounds) or the estimation of the ion ratio (LC-amenable compounds). For GC-amenable pesticides, limits of detection (LODs) ranged from 0.001 to 0.436 ?g L(-1) and limits of quantification (LOQs) from 0.003 to 1.452 ?g L(-1). For LC-amenable pesticides, LODs ranged from 0.003 to 1.048 ?g L(-1) and LOQs ranged from 0.011 to 3.494 ?g L(-1). Finally, the optimized method was applied to the analysis of fourteen real samples of infants from agricultural population. Some pesticides such as methoxyfenozide, tebufenozide, piperonyl butoxide and propoxur were found at concentrations ranged from 1.61 to 24.4 ?g L(-1), whereas methiocarb sulfoxide was detected at trace levels in two samples. PMID:21645688

Cazorla-Reyes, Rocío; Fernández-Moreno, José Luis; Romero-González, Roberto; Frenich, Antonia Garrido; Vidal, José Luis Martínez

2011-07-15

133

Neurotoxicity among pesticide applicators exposed to organophosphates.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

OBJECTIVES--An epidemiological study of 90 male pesticide applicators licensed in New York was conducted to investigate the effect of exposure to organophosphate pesticides on the peripheral nervous system. METHODS--A cohort of farmers and pesticide applicators from New York State were questioned off season (November 1988-February 1989) and again during the spraying season (April 1989-August 1989) about the presence of several acute signs and symptoms. Short term exposure was validated by mea...

Stokes, L.; Stark, A.; Marshall, E.; Narang, A.

1995-01-01

134

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

135

(Pesticide chemistry)  

Energy Technology Data Exchange (ETDEWEB)

This report summarizes a trip by L. W. Barnthouse of the Environmental Sciences Division (ESD), Oak Ridge National Laboratory (ORNL), to Hamburg, Federal Republic of Germany (FRG), where he participated in the 7th International Congress of Pesticide Chemistry. He chaired a workshop on experimental systems for determining effects of pesticides on nontarget organisms and gave an oral presentation at a symposium on pesticide risk assessment. Before returning to the United States, Dr. Barnthouse visited the Netherlands Institute for Sea Research in Texel, the Netherlands.

Barnthouse, L.W.

1990-09-04

136

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

137

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)Lmol(-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

138

Pesticides: Protecting Workers  

Science.gov (United States)

Protecting workers from potential effects of pesticides is an important role of EPA's Pesticide Program. Workers in several occupations may be exposed to pesticides when they: Prepare pesticides for ...

139

Pesticides in Groundwater  

Science.gov (United States)

Pesticides in Groundwater Care to guess how many pounds of pesticides the Nation used in 1964? How ... other locations, where they may cause health problems. Pesticides can contaminate groundwater Pesticide contamination of groundwater is ...

140

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 ...

 
 
 
 
141

Pesticide Poisoning  

Directory of Open Access Journals (Sweden)

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

Neva Sataloglu

2007-06-01

142

Pesticide Poisoning  

Directory of Open Access Journals (Sweden)

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

Neva Sataloglu

2007-06-01

143

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 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)

1963-09-01

144

Potential developmental neurotoxicity of pesticides used in Europe  

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

Grandjean Philippe

2008-10-01

145

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.

146

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

147

Evaluation of carbamate insecticides as chemotherapeutic agents for cancer  

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

Mohd. Amanullah; Hari Babu

2011-01-01

148

Validation:  

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Validation is establishing documented evidence, which provides high degreeassurance that a specific process will consistently produce a product meetingits predetermined specification and quality characteristics.Butvalidation itself does not improve process but assures that the process hasbeen properly developed and is under control.

2006-01-01

149

Synthesis of labelled pesticides  

International Nuclear Information System (INIS)

N, N-dialkyl-carbamic acid-trimethylsilyl-esters were synthesized starting with "1"4CO_2. The new synthesis method is simple and provides good radiochemical yield. Silul-carbaminates directly or through carbamyl-halogenides may be used for preparation of labelled herbicides: carbamates, thiocarbamates and ureas

1981-12-08

150

Test/QA plan for the validation of the verification protocol for high speed pesticide spray drift reduction technologies for row and field crops  

Science.gov (United States)

This test/QA plan for evaluation the generic test protocol for high speed wind tunnel, representing aerial application, pesticide spray drift reduction technologies (DRT) for row and field crops is in conformance with EPA Requirements for Quality Assurance Project Plans (EPA QA/R...

151

Test/QA plan for the validation of the verification protocol for low speed pesticide spray drift reduction technologies for row and field crops  

Science.gov (United States)

This test/QA plan for evaluation the generic test protocol for high speed wind tunnel, representing aerial application, pesticide spray drift reduction technologies (DRT) for row and field crops is in conformance with EPA Requirements for Quality Assurance Project Plans (EPA QA/R...

152

Validation of method for determination of different classes of pesticides in aqueous samples by dispersive liquid-liquid microextraction with liquid chromatography-tandem mass spectrometric detection.  

Science.gov (United States)

In this study, a simple, rapid and efficient method has been developed for the extraction and preconcentration of different classes of pesticides, carbofuran (insecticide), clomazone (herbicide) and tebuconazole (fungicide) in aqueous samples by dispersive liquid-liquid microextraction (DLLME) coupled with liquid chromatography-tandem mass spectrometric detection. Some experimental parameters that influence the extraction efficiency, such as the type and volume of the disperser solvents and extraction solvents, extraction time, speed of centrifugation, pH and addition of salt were examined and optimized. Under the optimum conditions, the recoveries of pesticides in water at spiking levels between 0.02 and 2.0 microg L(-1) ranged from 62.7% to 120.0%. The relative standard deviations varied between 1.9% and 9.1% (n=3). The limits of quantification of the method considering a 50-fold preconcentration step were 0.02 microg L(-1). The linearity of the method ranged from 1.0 to 1000 microg L(-1) for all compounds, with correlation coefficients varying from 0.9982 to 0.9992. Results show that the method we propose can meet the requirements for the determination of pesticides in water samples. The comparison of this method with solid-phase extraction indicates that DLLME is a simple, fast, and low-cost method for the determination of pesticides in natural waters. PMID:20381690

Caldas, Sergiane Souza; Costa, Fabiane Pinho; Primel, Ednei Gilberto

2010-04-14

153

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

Science.gov (United States)

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

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

2007-03-01

154

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

Science.gov (United States)

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

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

2011-01-01

155

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  

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. 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

156

Antimicrobial Pesticides  

Science.gov (United States)

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

157

Pesticide Poisoning  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

Neva Sataloglu; Berna Aydin; Ahmet Turla

2007-01-01

158

Total Pesticide Exposure Calculation among Vegetable Farmers in Benguet, Philippines  

International Nuclear Information System (INIS)

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

1100-01-00

159

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

Science.gov (United States)

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

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

2014-07-01

160

In vitro human phase I metabolism of xenobiotics I: pesticides and related compounds used in agriculture and public health, May 2003.  

Science.gov (United States)

This is the first revision of a database covering human phase I enzymes and their isoforms that metabolize pesticides and related compounds. The original version included enzymes that metabolize chloroacetamide and triazine herbicides, and organophosphorus insecticides. This revision also includes carbamate, nicotinoid, and pyrethroid insecticides and insect repellents. PMID:12898643

Hodgson, Ernest

2003-01-01

 
 
 
 
161

(1)H NMR-based metabonomic profiling of rat serum and urine to characterize the subacute effects of carbamate insecticide propoxur.  

Science.gov (United States)

Carbamate insecticide propoxur is widely used in agriculture and public health programs. To prevent adverse health effects arising from exposure to this insecticide, sensitive methods for detection of early stage organismal changes are necessary. We present here an integrative metabonomic approach to investigate toxic effects of pesticide in experimental animals. Results showed that propoxur even at low dose levels can induce oxidative stress, impair liver function, enhance ketogenesis and fatty acid ?-oxidation, and increase glycolysis, which contribute to the hepatotoxocity. These findings highlight the applicability of (1)H NMR spectroscopy and multivariate statistics in elucidating the toxic effects of propoxur. PMID:22780197

Liang, Yu-Jie; Wang, Hui-Ping; Long, Ding-Xin; Wu, Yi-Jun

2012-09-01

162

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

Problem statement: Contamination associated with pesticide use has increased as well, adversely impacting the environment and causing human health risks through residues on food. Approach: This study reports the extraction of Fenvalerate (FE) in chilies using QuEChERS based on High Performance Liquid Chromatography (HPLC) describes a simple, fast and inexpensive method. The chillie was extracted with acetonitrile Aliquots were cleaned-up using Solid Phase Ext...

2010-01-01

163

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

International Nuclear Information System (INIS)

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

2007-03-01

164

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

Science.gov (United States)

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

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

2010-04-15

165

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

Scientific Electronic Library Online (English)

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

David, Dallos Corredor; Jairo Arturo, Guerrero Dallos.

2005-12-05

166

Surveying of Pesticides Commonly on the Markets of Iran in 2009  

Directory of Open Access Journals (Sweden)

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

Rouhullah Dehghani

2011-10-01

167

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

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

Jerkofsky, M.; Abrahamsen, L. H.

1983-01-01

168

Pesticide Spray and Dust Drift  

Science.gov (United States)

Pesticide Spray and Dust Drift Quick Resources 3/31/14: EPA Response to "Pesticides in the Air – ... works: pesticide volatilization Worker risk assessment Questions on Pesticides? National Pesticide Information Center (NPIC) 1-800-858- ...

169

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 and ... storage needs by buying only the amount of pesticide that you will need in the near future ...

170

Pesticides and Pregnancy  

Science.gov (United States)

... or visit us online at: www.OTISpregnancy.org . Pesticides and Pregnancy This sheet talks about the risks ... advice from your health care provider. What are pesticides? A pesticide is a substance used to prevent ...

171

Antimicrobial Pesticide Products  

Science.gov (United States)

... as of: December 1, 2004 Resources Questions On Pesticides? National Pesticide Information Center (NPIC) 1-800-858-7378 On ... Types of Antimicrobial Products For More Information Antimicrobial pesticides are substances or mixtures of substances used to ...

172

Illegal Pesticide Products  

Science.gov (United States)

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

173

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 ...

174

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

Science.gov (United States)

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, PPropanil highly promoted haemoglobin synthesis and up-regulated genes specifically related to defence mechanisms (e.g., innate immunity response systems) and neuronal pathways. Pesticide-specific toxic responses were found but there is little evidence for transcriptional responses purely restricted to genes associated with the pesticide target site or mechanism of toxicity. PMID:20092900

Pereira, Joana Luísa; Hill, Christopher J; Sibly, Richard M; Bolshakov, Viacheslav N; Gonçalves, Fernando; Heckmann, Lars-Henrik; Callaghan, Amanda

2010-05-01

175

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

Science.gov (United States)

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

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

2009-01-01

176

[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

177

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

178

Micellar electrokinetic chromatography with amperometric detection and off-line solid-phase extraction for analysis of carbamate insecticides.  

Science.gov (United States)

Six selected primary carbamate insecticides, methomyl, carbaryl, carbofuran, propoxur, isoprocarb, and promecarb, were hydrolyzed in alkaline solution, resulting in electroactive derivatives detectable at a platinum (Pt) electrode poised at +0.8 V vs Ag/AgCl (3 M NaCl). The Pt electrode was inserted into a small electrochemical cell and positioned close to the capillary outlet as an end-column detector to detect the carbamate derivatives after electrophoretic separation. Based on their predicted pK(a) values and aqueous solubilities, micellar electrokinetic chromatography (MEKC) was optimized for baseline separation of the derivatives using 20 mM borate, pH 10.2 containing 20 mM sodium dodecyl sulfate as a running buffer. When combined with solid-phase extraction (SPE) on octadecyl silica, a preconcentration factor of 100-fold achieved detection to 0.5 microM methomyl and to 0.01 microM for the remaining five pesticides, significantly below the level regulated by government agencies of most countries. The SPE-MEKC method when applied to the separation and analysis of spiked river water and soil samples, yielded results with excellent reproducibility, recovery and selectivity. PMID:20598698

Santalad, Apichai; Zhou, Lin; Shang, Fengjun; Fitzpatrick, Dara; Burakham, Rodjana; Srijaranai, Supalax; Glennon, Jeremy D; Luong, John H T

2010-08-01

179

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.  

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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 extraccio. 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.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 capillary 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

2006-10-01

180

Radiochemical neutron activation analysis of selenium using carbamate extraction  

International Nuclear Information System (INIS)

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

1982-10-20

 
 
 
 
181

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

Science.gov (United States)

We tested 200 pesticides, including some of their isomers and metabolites, for agonism and antagonism to two human estrogen receptor (hER) subtypes, hERalpha and hERbeta, and a human androgen receptor (hAR) by highly sensitive transactivation assays using Chinese hamster ovary cells. The test compounds were classified into nine groups: organochlorines, diphenyl ethers, organophosphorus pesticides, pyrethroids, carbamates, acid amides, triazines, ureas, and others. These pesticides were tested at concentrations hexachloride (BHC) and delta-BHC and the carbamate insecticide methiocarb were predominantly hERbeta rather than hERalpha agonistic. Weak antagonistic effects toward hERalpha and hERbeta were shown in five and two pesticides, respectively. On the other hand, none of tested pesticides showed hAR-mediated androgenic activity, but 66 of 200 pesticides exhibited inhibitory activity against the transcriptional activity induced by 5alpha-dihydrotestosterone. In particular, the antiandrogenic activities of two diphenyl ether herbicides, chlornitrofen and chlomethoxyfen, were higher than those of vinclozolin and p,p -dichlorodiphenyl dichloroethylene, known AR antagonists. The results of our ER and AR assays show that 34 pesticides possessed both estrogenic and antiandrogenic activities, indicating pleiotropic effects on hER and hAR. We also discussed chemical structures related to these activities. Taken together, our findings suggest that a variety of pesticides have estrogenic and/or antiandrogenic potential via ER and/or AR, and that numerous other manmade chemicals may also possess such estrogenic and antiandrogenic activities. PMID:15064155

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

2004-04-01

182

The development, validation and application of a GC-dual detector (NPD-ECD) multi-pesticide residue method for monitoring bee poisoning incidents.  

Science.gov (United States)

A simple multiresidue method based on matrix solid phase dispersion (MSPD) combined with clean-up has been developed for the simultaneous screening of 153 pesticides in honeybees suspected of suffering from pesticide poisoning during field spraying. Extraction and clean-up were carried out in a glass column containing anhydrous sulphate, 2.0g of octadecyl (C18) and a 2.0-g sample of bees (23 insects on average) macerated with 4.0g of Florisil. An additional layer of anhydrous sodium sulphate was added, and acetonitrile was used as the elution solvent. This combination of clean-up steps ensured an efficient purification. A gas chromatograph with dual selective detectors for electron capture and nitrogen-phosphorous was used. The results presented in this paper demonstrate that matrix solid-phase dispersion (MSPD) with the one-step clean-up procedure is the most effective extraction technique. MSPD method recoveries ranged from 70 to 118%, with precision values expressed as a relative standard of cypermethrin (in 51% of the samples, 0.008-0.563µg/bee), chlorpyrifos (27%, 0.001-51.5µg/bee) and biphentin (21%, 0.002-0.012µg/bee). PMID:23916014

?ozowicka, Bo?ena

2013-11-01

183

Stir bar sorptive extraction coupled to liquid chromatography-tandem mass spectrometry for the determination of pesticides in water samples: method validation and measurement uncertainty.  

Science.gov (United States)

Stir bar sorptive extraction followed by liquid desorption and high performance liquid chromatography with tandem mass spectrometry (SBSE-LD-LC-MSMS) has been developed for the determination of 15 pesticides or selected metabolites from different families (herbicides, insecticides, fungicides) in surface water samples. The optimization of parameters that could influence SBSE-LD efficiency was carried out by means of experimental design. Optimized conditions were established as follows concerning extraction time, stirring speed, aqueous medium characteristics (ionic strength and polarity) and back desorption solvent and time, respectively: 3 h (800 rpm), addition of 10% of sodium chloride, no addition of methanol as organic modifier, and 15 min ultrasonic desorption in equivolume mixtures of acetonitrile-methanol. A specific and thorough cleanup procedure was developed and applied to each stir bar to avoid possible carry-over between consecutive extractions with the same stir bar. Pesticide quantification in water was achieved thanks to matrix matched calibration. Mean recoveries ranged from 93 to 101% (RSD LCMSMS method was evaluated by analyzing surface water samples and by comparing with conventional solid phase extraction-LC-MSMS procedure. PMID:24148364

Margoum, Christelle; Guillemain, Céline; Yang, Xi; Coquery, Marina

2013-11-15

184

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

Directory of Open Access Journals (Sweden)

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

185

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

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

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

2012-01-01

186

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 <6% and <24% for the OPPs, <1% for the carbamates and pyrethrins and pyrethroids, and <1% and <4% for the DTC metabolites, respectively. The findings indicate that dietary exposures to all the pesticide residues analysed in this study were unlikely to pose unacceptable health risks to the Hong Kong population. PMID:24588687

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

2014-05-01

187

Contribution of citrulline to the formation of ethyl carbamate during Chinese rice wine production.  

Science.gov (United States)

Ethyl carbamate is a well-known carcinogen and widely occurs in Chinese rice wine. To provide more clues to minimise ethyl carbamate accumulation, the levels of possible precursors of ethyl carbamate in Chinese rice wine were investigated by HPLC. Studies of the possible precursors of ethyl carbamate in Chinese raw rice wine with various additives and treatments indicated that significant amounts of urea can account for ethyl carbamate formation. It was also recognised that citrulline is another important precursor that significantly affects ethyl carbamate production during the boiling procedure used in the Chinese rice wine manufacturing process. Besides urea and citrulline, arginine was also found to be an indirect ethyl carbamate precursor due to its ability to form urea and citrulline by microorganism metabolism. PMID:24386880

Wang, Peihong; Sun, Junyong; Li, Xiaomin; Wu, Dianhui; Li, Tong; Lu, Jian; Chen, Jian; Xie, Guangfa

2014-04-01

188

[The monitoring of cholinesterases in farm workers and tradesmen exposed to phosphoric esters and carbamates].  

Science.gov (United States)

Cholinesterase (ChE) levels (Ellman method) were monitored in 90 subjects (69 males and 21 females) exposed to carbamate and organophosphate pesticides (78 agricultural workers and 12 pesticide vendors). Pre-exposure baseline values of plasma and red blood cell cholinesterase activities were defined for each subject with two blood samples (23 workers) or three blood samples (59 workers) taken almost thirty days after the last exposure. After control of intra-individual variation, 8 subjects with only one pre-exposure value and 13 with a coefficient of variation above 30% were excluded. For the other 59 subjects, the intra-individual variation of erythrocyte ChE (16%) was similar to the inter-individual one (15%), whereas the inter-individual variation of plasma ChE (21%) was higher than the intra-individual one (14%). Laboratory variation for plasma ChE measurements was 8%. Baseline values were analyzed (ANOVA) for sex, age, task and hour and season of sampling. Both erythrocyte and plasma enzymes, corrected for hematocrit, were lower in females. Plasma cholinesterase activity was lower in "re-entry" agricultural workers and in pesticide vendors. Post-exposure cholinesterase activity was measured in 54 workers within a few (1-21) days after last handling. Average relative reduction was 15.2% (95% C.I. = 4.9%-25.5%) in erythrocyte cholinesterase activity and 29.1% (95% C.I. = 18.2%-40.1%) in plasma cholinesterase activity. The one-way variance analysis showed marked plasma ChE reduction in mixers, loaders and appliers (36%, 95% C.I. = 24%-48%) and in parathion handlers (35%, 95% C.I. = 21%-49%. No significant reduction in blood cell cholinesterase activity in relation to task and to pesticide handled was observed. We conclude that the intra-individual variations of the baseline values were higher for three repetitions (88% and 84% of the population were within a variability of less than 30%, for AChE and for ChE respectively) than for two repetitions (91% and 88% of the population were within 30% of variability for AChE and for ChE respectively). The figures show a greater sensitivity of plasma ChE activity in acute exposure, probably due to a poor reliability in detection of erythrocyte ChE by local laboratories. The maximum reduction (38%, 95% C.I. = 22%-53%) in plasma ChE activity was observed within six days of the last exposure in loaders and appliers. PMID:1630402

Faustini, A; Arpaia, F; Pagliarella, P; Forastiere, F; Papini, P; Perucci, C A

1992-01-01

189

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

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

A.R Rahmani

2011-10-01

190

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

International Nuclear Information System (INIS)

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

1998-04-19

191

P3 SAR exploration of biphenyl carbamate based Legumain inhibitors.  

Science.gov (United States)

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

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

2014-06-01

192

A facile route to paclitaxel C-10 carbamates.  

Science.gov (United States)

A general protocol for the synthesis of paclitaxel C-10 carbamates is described. The method entails MeI-mediated activation of 2'-O-TBS-7-O-TES-10-O-deacetyl-paclitaxel-10-O-carbonylimidazole prior to reaction with amines. This method is effective for the synthesis of paclitaxel C-10 derivatives, including bifunctional molecules. PMID:15863300

Ballatore, Carlo; Aspland, Simon E; Castillo, Rosario; Desharnais, Joel; Eustaquio, Trisha; Sun, Chengzao; Castellino, Angelo J; Smith, Amos B

2005-05-16

193

[Pesticide poisoning].  

Science.gov (United States)

Pesticide intoxications are mainly accidental with a benign course, such as ingestions of diluted fertilizers or low concentration antivitamin K rodenticides, ant-killing products or granules of molluscicides containing 5% metaldehyde. Voluntary intoxications by chloralose, strychnine, organophosphorus or organochlorine insecticides, concentrated anti-vitamin K products, herbicides such as paraquat, chlorophenoxy compounds, glyphosate or chlorates may be severe. Toxicity is due to active substances but also to solvents or surfactants included in the composition. Analysis done in a toxicology laboratory help in establishing diagnosis, prognosis and treatment. Poison centres may be called constantly to help for the evaluation of these intoxications. PMID:10748667

Harry, P

2000-02-15

194

Intoxicación por plaguicidas Pesticide poisoning  

Directory of Open Access Journals (Sweden)

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

195

Intoxicación por plaguicidas / Pesticide poisoning  

Scientific Electronic Library Online (English)

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

A., Ferrer.

196

Disposal of obsolete pesticides, the case of Ethiopia.  

Science.gov (United States)

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

Haylamicheal, Israel D; Dalvie, Mohamed A

2009-04-01

197

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

Science.gov (United States)

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

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

2010-07-15

198

Pesticide resistance mechanisms produced by field selection pressures on Anopheles nigerrimus and A. culicifacies in Sri Lanka  

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In Sri Lanka, Anopheles nigerrimus is resistant to a range of organophosphate and carbamate insecticides at both the larval and adult stages. Biochemical studies indicate that an alteration in acetylcholinesterase is the basis of resistance rather than increased metabolic breakdown of the insecticides. In contrast, A. culicifacies is resistant only to malathion and closely related compounds containing a carboxylate ester bond. Agricultural pesticides are the sole source of selection pressure ...

Hemingway, J.; Jayawardena, K. G. I.; Herath, P. R. J.

1986-01-01

199

Development, validation and application of a SDME/GC-FID methodology for the multiresidue determination of organophosphate and pyrethroid pesticides in water.  

Science.gov (United States)

A single-drop microextraction (SDME) procedure was developed for the analysis of organophosphorus and pyrethroid pesticides in water by gas chromatography (GC) with flame ionization detection (GC-FID). The significant parameters that affect SDME performance, such as the selection of microextraction solvent, solvent volume, extraction time, and stirring rate, were studied and optimized using a tool screening factorial design. The limits of detection (LODs) in water for the four investigated compounds were between 0.3 and 3.0 microgL(-1), with relative standard deviations ranging from 7.7 to 18.8%. Linear response data were obtained in the concentration range of 0.9-6.0 microg L(-1) (lambda-cyhalothrin), 3.0-60.0 microg L(-1) (methyl parathion), 9.0-60.0 microg L(-1) (ethion), and 9.0-30.0 microg L(-1) (permethrin), with correlation coefficients ranging from 0.9337 to 0.9977. The relative recoveries for the spiked water ranged from 73.0 to 104%. Environmental water samples (n=26) were successfully analyzed using the proposed method and methyl parathion presented concentration up to 2.74 microg L(-1). The SDME method, coupled with GC-FID analysis, provided good precision, accuracy, and reproducibility over a wide linear range. Other highlights of the method include its ease of use and its requirement of only small volumes of both organic solvent and sample. PMID:19635370

Pinheiro, Anselmo de Souza; de Andrade, Jailson B

2009-10-15

200

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

Directory of Open Access Journals (Sweden)

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

 
 
 
 
201

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

Science.gov (United States)

Pesticides almost always occur in mixtures with other ones. The toxicological effects of low-dose pesticide mixtures on the human health are largely unknown, although there are growing concerns about their safety. The combined toxicological effects of two or more components of a pesticide mixture can take one of three forms: independent, dose addition or interaction. Not all mixtures of pesticides with similar chemical structures produce additive effects; thus, if they act on multiple sites their mixtures may produce different toxic effects. The additive approach also fails when evaluating mixtures that involve a secondary chemical that changes the toxicokinetics of the pesticide as a result of its increased activation or decreased detoxification, which is followed by an enhanced or reduced toxicity, respectively. This review addresses a number of toxicological interactions of pesticide mixtures at a molecular level. Examples of such interactions include the postulated mechanisms for the potentiation of pyrethroid, carbaryl and triazine herbicides toxicity by organophosphates; how the toxicity of some organophosphates can be potentiated by other organophosphates or by previous exposure to organochlorines; the synergism between pyrethroid and carbamate compounds and the antagonism between triazine herbicides and prochloraz. Particular interactions are also addressed, such as those of pesticides acting as endocrine disruptors, the cumulative toxicity of organophosphates and organochlorines resulting in estrogenic effects and the promotion of organophosphate-induced delayed polyneuropathy. PMID:22728724

Hernández, Antonio F; Parrón, Tesifón; Tsatsakis, Aristidis M; Requena, Mar; Alarcón, Raquel; López-Guarnido, Olga

2013-05-10

202

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

International Nuclear Information System (INIS)

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

2006-01-01

203

75 FR 34448 - Pesticides; Draft Guidance for Pesticide Registrants on False or Misleading Pesticide Product...  

Science.gov (United States)

...Draft Guidance for Pesticide Registrants on False or Misleading Pesticide Product Brand Names...Registration Notice (PR Notice) entitled ``False or Misleading Pesticide Product Brand Names...Registration Notice (PR Notice) entitled ``False or Misleading Pesticide Product Brand...

2010-06-17

204

75 FR 28012 - Pesticides; Draft Guidance for Pesticide Registrants on False or Misleading Pesticide Product...  

Science.gov (United States)

...Draft Guidance for Pesticide Registrants on False or Misleading Pesticide Product Brand Names...Registration Notice (PR Notice) entitled ``False or Misleading Pesticide Product Brand Names...pesticide product brand names that may be false or misleading, either by themselves...

2010-05-19

205

Molybdenum(V) dimeric complexes with dialkyl carbamates  

International Nuclear Information System (INIS)

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

1985-01-01

206

Erythema multiforme-like eruption due to carbamates and thiuram.  

Science.gov (United States)

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

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

2006-01-01

207

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

208

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

Directory of Open Access Journals (Sweden)

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

?or?evi? J.

2010-01-01

209

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

210

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

211

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

International Nuclear Information System (INIS)

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

2009-01-01

212

The formation of carbamate ions in interstellar ice analogues.  

Science.gov (United States)

Carbon dioxide and ammonia are two of the most abundant species in astrophysical media, where they can react in the solid phase under certain conditions. This contribution presents a study of this reaction both in the presence of water and for anhydrous samples. It is shown that after deposition at 15 K, the reaction can start by warming the deposit, and the process continues on up to a temperature of 220 K. Reaction products are studied using infrared spectroscopy and mass spectrometry. For anhydrous samples, a 2?:?1 stoichiometry mixture of NH3?:?CO2 gives the highest yield of products. The reaction is favored when a small amount of water is present, which enables ammonia and carbon dioxide molecules to collide within the pores and channels of the amorphous water solid. Large concentration of water, on the other hand, hampers such collisions. The main reaction product is found to be ammonium carbamate, but also carbamic acid is formed, and, in the presence of water, ammonium bicarbonate is produced as well. Theoretical calculations are carried out to provide the basis for the assignment of the spectra. Some of the experiments presented in this contribution consist of the generation of a compact water ice matrix where the carbamate and ammonium ions are embedded. If such a system was found in astrophysical media, it is shown that the ammonium ion could not be detected, whereas two infrared features of the carbamate ion in the 1040 to 1115 cm(-1) (9 to 9.6 ?m) region could enable the observation of this species. PMID:24162236

Rodríguez-Lazcano, Yamilet; Maté, Belén; Herrero, Víctor J; Escribano, Rafael; Gálvez, Óscar

2014-02-28

213

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

Scientific Electronic Library Online (English)

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

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

214

Microcalorimetric study of the inhibition of butyrylcholinesterase by carbamates.  

Science.gov (United States)

The inhibition of horse serum butyrylcholinesterase (EC 3.1.1.8) by three carbamates (eserine, neostigmine, and rivastigmine) was studied by flow microcalorimetry at 37 degrees C in Tris buffer (pH 7.5). The kinetics of carbamylation was studied in the absence or presence of the substrate, butyrylcholine, using an extension of the model described by Stojan and coworkers (FEBS Lett. 440 (1998) 85-88). The model was fitted to the data by a nonlinear regression procedure using simulated annealing followed by Marquardt's method. The affinity of the carbamates for the free enzyme increased in the order neostigminecarbamylation rates followed an inverse order. In the case of rivastigmine, the results suggested that an acyl-enzyme-inhibitor complex could be formed either by reversible binding of the carbamate to the acyl-enzyme or by acylation of the enzyme-inhibitor complex. This work confirms the usefulness of microcalorimetry to study irreversible or progressive inhibitors and emphasizes the need to investigate the binding of such compounds to intermediate enzyme forms. PMID:17950687

Debord, Jean; Laubarie, Cécile; Dantoine, Thierry

2008-02-15

215

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

Science.gov (United States)

...Specific Chemical Substances § 721.7200 Perfluoroalkyl aromatic carbamate... (a) Chemical substance and significant new...1) The chemical substance identified generically as perfluoroalkyl aromatic...

2009-07-01

216

Pesticide Fact Sheet: Fluroxypyr.  

Science.gov (United States)

This document contains up-to-date chemical information, including a summary of the Agency's regulatory position and rationale, on a specific pesticide or group of pesticides. A Fact Sheet is issued after registration of a new chemical.

1998-01-01

217

Pesticide Fact Sheet: Spinosad.  

Science.gov (United States)

This document contains up-to-date chemical information, including a summary of the Agency's regulatory position and rationale, on a specific pesticide or group of pesticides. A Fact Sheet is issued after Registration of a new chemical.

1997-01-01

218

Pesticide Fact Sheet: Flumetsulam.  

Science.gov (United States)

This document contains up-to-date chemical information, including a summary of the Agency's regulatory position and rationale, on a specific pesticides or group of pesticides. A Fact Sheet is issued after, registration of a new chemical.

1993-01-01

219

Pesticide Fact Sheet: Imazapyr.  

Science.gov (United States)

This document contains up-to-date chemical information, including a summary of the Agency's regulatory position and rationale, on a specific pesticide or group of pesticides. A Fact Sheet is issued after registration of a significantly changed use pattern...

1997-01-01

220

Common Pesticide Questions  

Science.gov (United States)

... with tack: Will the horse think it's a snack? Don't distress over uninvited guests (roaches)! PestiByte ... read our disclaimer | Contact us NPIC provides objective, science-based information about pesticides and pesticide-related topics ...

 
 
 
 
221

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

1996-07-01

222

Multiple pesticide exposures and the risk of multiple myeloma in Canadian men.  

Science.gov (United States)

Multiple myeloma (MM) has been linked to certain agricultural exposures, including pesticides. This analysis aimed to investigate the association between lifetime use of multiple pesticides and MM risk using two exposure metrics: number of pesticides used and days per year of pesticide use. A frequency-matched, population-based case-control study was conducted among men in six Canadian provinces between 1991 and 1994. Data from 342 MM cases and 1,357 controls were analyzed using logistic regression to calculate odds ratios (OR) and 95% confidence intervals. Pesticides were grouped by type, chemical class and carcinogenic potential, using a composite carcinogenic probability score. Selected individual pesticides were also examined. Regression models were adjusted for age, province of residence, use of proxy respondents, smoking and selected medical history variables. The overall pattern of results was complex. Positive trends in risk were observed for fungicides (ptrend=0.04) and pesticides classified as probably carcinogenic or higher (ptrend=0.03). Excess risks of MM were observed among men who reported using at least one carbamate pesticide (OR=1.94, 1.16-3.25), one phenoxy herbicide (OR=1.56, 1.09-2.25) and ?3 organochlorines (OR=2.21, 1.05-4.66). Significantly higher odds of MM were seen for exposure to carbaryl (OR=2.71, 1.47-5.00) and captan (OR=2.96, 1.40-6.24). Use of mecoprop for >2 days per year was also significantly associated with MM (OR=2.15, 1.03-4.48). Focusing on multiple pesticide exposures is important because this more accurately reflects how exposures occur in occupational settings. Significant associations observed for certain chemical classes and individual pesticides suggest that these may be MM risk factors. PMID:23564249

Kachuri, Linda; Demers, Paul A; Blair, Aaron; Spinelli, John J; Pahwa, Manisha; McLaughlin, John R; Pahwa, Punam; Dosman, James A; Harris, Shelley A

2013-10-15

223

Pesticide distributions and population declines of California, USA, alpine frogs, Rana muscosa and Rana sierrae.  

Science.gov (United States)

Atmospherically deposited pesticides from the intensively cultivated Central Valley of California, USA, have been implicated as a cause for population declines of several amphibian species, with the strongest evidence for the frogs Rana muscosa and Rana sierrae at high elevation in the Sierra Nevada mountains. Previous studies on these species have relied on correlations between frog population status and either a metric for amount of upwind pesticide use or limited measurements of pesticide concentrations in the field. The present study tested the hypothesis that pesticide concentrations are negatively correlated with frog population status (i.e., fraction of suitable water bodies occupied within 2 km of a site) by measuring pesticide concentrations in multiple media twice at 28 sites at high elevation in the southern Sierra Nevada. Media represented were air, sediment, and Pseudacris sierra tadpoles. Total cholinesterase (ChE), which has been used as an indicator for organophosphorus and carbamate pesticide exposure, was also measured in P. sierra tadpoles. Results do not support the pesticide-site occupancy hypothesis. Among 46 pesticide compounds analyzed, nine were detected with ? 30% frequency, representing both historically and currently used pesticides. In stepwise regressions with a chemical metric and linear distance from the Central Valley as predictor variables, no negative association was found between frog population status and the concentration of any pesticide or tadpole ChE activity level. By contrast, frog population status showed a strong positive relationship with linear distance from the Valley, a pattern that is consistent with a general west-to-east spread across central California of the amphibian disease chytridiomycosis observed by other researchers. PMID:21298712

Bradford, David F; Knapp, Roland A; Sparling, Donald W; Nash, Maliha S; Stanley, Kerri A; Tallent-Halsell, Nita G; McConnell, Laura L; Simonich, Staci M

2011-03-01

224

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

Directory of Open Access Journals (Sweden)

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

J. G. Myburgh

2012-05-01

225

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 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

2004-05-20

226

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 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

1996-07-01

227

Safe Disposal of Pesticides  

Science.gov (United States)

Safe Disposal of Pesticides Esta página Web está disponible en español The best way to dispose of small amounts of excess pesticides is ... 1-800-CLEANUP. State and local laws regarding pesticide disposal may be stricter than the Federal requirements ...

228

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.

229

Design and synthesis of bis-carbamate analogs of cyclic bis-(3'-5')-diguanylic acid (c-di-GMP) and the acyclic dimer PGPG.  

Science.gov (United States)

The bacterial second messenger cyclic bis-(3'-5')-diguanylic acid (c-di-GMP) regulates diverse Gram-negative bacterial virulence functions. The pathways that control, or are controlled by, c-di-GMP suggest that c-di-GMP signaling systems may encompass potential drug targets. It is presently undetermined, however, whether up- or down-modulation of c-di-GMP signaling would be the desired therapeutic state. We addressed potential drug target validation by synthesizing nonhydrolysable carbamate analogs of both the cyclic dinucleotide and the acyclic (seco) dinucleotide. A molecular docking simulation of the carbamate isostere suggests that this analog is capable of assuming the correct conformation and pose at a c-di-GMP binding site. PMID:19003573

Kline, Toni; Jackson, Stona R; Deng, Wei; Verlinde, Christophe L M J; Miller, Samuel I

2008-12-01

230

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

Directory of Open Access Journals (Sweden)

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

Rodríguez-Forero Adriana

2012-03-01

231

Pesticides and children  

International Nuclear Information System (INIS)

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

2004-07-15

232

Understanding Pesticide Behaviour At The Catchment Scale  

Science.gov (United States)

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

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

233

Mapping ecological risk of agricultural pesticide runoff.  

Science.gov (United States)

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

Schriever, Carola Alexandra; Liess, Matthias

2007-10-01

234

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

Directory of Open Access Journals (Sweden)

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

Md. Shakhaoat Hossain

2013-02-01

235

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

Science.gov (United States)

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

236

Versatile approach to ?-alkoxy carbamate synthesis and stimulus-responsive alcohol release†  

Science.gov (United States)

A series of ?-alkoxy carbamates that cleave under mild conditions to release alcohols has been synthesized through a multicomponent process. The relationship between structural features in these compounds and the rate of alcohol release in the presence of basic hydrogen peroxide has been studied. The preparation of carbamates that cleave under other conditions has been demonstrated.

Mosey, R. Adam; Floreancig, Paul E.

2012-01-01

237

Versatile approach to ?-alkoxy carbamate synthesis and stimulus-responsive alcohol release.  

Science.gov (United States)

A series of ?-alkoxy carbamates that cleave under mild conditions to release alcohols has been synthesized through a multicomponent process. The relationship between structural features in these compounds and the rate of alcohol release in the presence of basic hydrogen peroxide has been studied. The preparation of carbamates that cleave under other conditions has been demonstrated. PMID:22936329

Mosey, R Adam; Floreancig, Paul E

2012-10-21

238

pesticides workshop presentation kevin odonnell  

...in the Safe Use of Pesticides Kevin O’Donnell CAFRE • Greenmount...Campus • Enniskillen Campus Industry Training Pesticides Training Safe Use of Pesticides – PA1, PA2a Storage of Pesticides - NSK Sale or Supply of...NSK Sale or Supply of Pesticides – BASIS Cert. PA1 – Foundation Unit...

239

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

2009-04-01

240

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

 
 
 
 
241

Evaluation of carbamate insecticides as chemotherapeutic agents for cancer  

Directory of Open Access Journals (Sweden)

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

Mohd. Amanullah

2011-01-01

242

Influence of pesticide regulation on acute poisoning deaths in Sri Lanka  

Directory of Open Access Journals (Sweden)

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

Roberts Darren M.

2003-01-01

243

Solvent-dependent enantiodivergence in the chlorocyclization of unsaturated carbamates.  

Science.gov (United States)

A remarkable solvent-controlled enantiodivergence is seen in the hydroquinidine 1,4-phthalazinediyl diether ((DHQD)2PHAL)-catalyzed chlorocyclization of unsaturated carbamates. Eyring plot analyses of this previously unreported reaction are used to probe and compare the R- and S-selective pathways. In the CHCl3/hexanes solvent system, the pro-R process shows a surprising increase in selectivity with increasing temperature. These studies point to a strongly solvent-dependent entropy-enthalpy balance between the pro-R and pro-S pathways. PMID:23671005

Garzan, Atefeh; Jaganathan, Arvind; Salehi Marzijarani, Nastaran; Yousefi, Roozbeh; Whitehead, Daniel C; Jackson, James E; Borhan, Babak

2013-07-01

244

Pesticides: chemicals for survival  

Energy Technology Data Exchange (ETDEWEB)

Pesticides are chemicals used to control pests such as insects, weeds, plant diseases, nematodes, and rodents. The increased use of pesticides since 1945 has greatly aided the increase in crop production, protected livestock from diseases such as trypanosomiasis, protected man from diseases such as malaria and filarisis, decreased losses of stored grain, and has generally improved man's welfare. Despite the enormous benefits derived from pesticides these chemicals are not problem-free. Many pesticides are toxic to living organisms and interfere with specific biochemical systems. To measure the very small quantities of a pesticide radiolabelled chemicals are frequently essential, particularly to measure changes in the chemical structure of the pesticide, movement of the pesticide in soil, plants, or animals, amounts of pesticide going through various steps in food processing, etc. The use of radiolabelled pesticides is briefly shown for metabolism of the pesticide in crop species, metabolism in ruminant, in chickens and eggs, in soil, and possibly leaching and sorption in soil, hydrolysis, bio-concentration, microbial and photodegradation, and toxicity studies.

Lindquist, D.A. (Joint FAO/IAEA Div. of Isotope and Radiation Applications of Atomic Energy for Food and Agricultural Development, Vienna (Austria))

1981-09-01

245

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.

2010-10-01

246

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

Scientific Electronic Library Online (English)

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

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

247

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

248

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  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 Haplu...

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

2005-01-01

249

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

Science.gov (United States)

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

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

2005-06-01

250

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

Scientific Electronic Library Online (English)

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

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

251

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

252

Functionalisation of cellulosic substrates by a facile solventless method of introducing carbamate groups  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A facile method for the introduction of carbamate groups in cellulosic substrates is described. Woven cellulosic fabrics were padded with non-alkali treatment solutions containing PEG 2000, urea, and LiCl and heated at elevated temperatures to obtain cellulose carbamate fabrics. The introduction of carbamate groups was confirmed with FTIR-ATR and NMR spectroscopy, and the treated fabrics exhibited nitrogen contents of 0.10-2.04% (DS 0.01-0.25). There was a reduction in the viscosity-average d...

Vo, Loan Thi To; Siroka, Barbora; Manian, Avinash Pradip; Bechtold, Thomas

2010-01-01

253

Multiple myeloma and exposure to pesticides: a Canadian case-control study.  

Science.gov (United States)

The objective of this study was to investigate the putative associations of specific pesticides with multiple myeloma. A matched, population-based, case-control study was conducted among men residing in six Canadian provinces (Quebec, Ontario, Manitoba, Saskatchewan, Alberta, and British Columbia). Data were collected on 342 multiple myelome cases and 1506 age and province of residence matched controls. Data were collected by mailed questionnaires to capture demographic characteristics, antecedent medical history, detailed lifetime occupational history, smoking history, family history of cancer, and exposure to broadly characterized pesticides at home, work, and practicing hobbies. Details of pesticide exposures were collected by telephone interview for those who reported 10 hours or more per year of exposure. Exposure to pesticides grouped into major chemical classes resulted in increased risk being detected only for carbamate insecticides [odds ratio (OR) and 95% confidence interval (CI) 1.90 (1.11, 3.27) adjusted for potential confounders]. An exposure to fungicide captan [2.35 (1.03, 5.35)] was positively associated with the incidence of multiple myeloma. While an exposure to carbaryl [1.89 (0.98, 3.67)] was associated with the incidence of multiple myelome with borderline significance. The authors further suggest that certain pesticide exposures may have a role in multiple myeloma etiology, and identify specific factors warranting investigation in other populations. PMID:22191502

Pahwa, Punam; Karunanayake, Chandima P; Dosman, James A; Spinelli, John J; McDuffie, Helen H; McLaughlin, John R

2012-01-01

254

Comparative toxicity of the pesticides carbofuran and malathion to the freshwater flagellate Euglena gracilis.  

Science.gov (United States)

Pesticides are toxic chemicals used for agricultural as well as non-agricultural purposes. The toxicity of pesticides does not remain limited to the site of application but they also cause toxicity to non-target organisms in terrestrial as well as in aquatic environments. This study discusses the comparative toxicity of a carbamate (carbofuran) and an organophosphorus (malathion) pesticide to the freshwater flagellate Euglena gracilis during short- and long-term exposures. To evaluate the toxicity of the pesticides, different parameters of the flagellate, like cell density, motility, swimming velocity, cell shape, gravitactic orientation, photosynthetic efficiency, and concentration of light harvesting pigments, were used as end points. Carbofuran was found to be more toxic to E. gracilis than malathion and adversely affected almost all the tested parameters in short- and long-term experiments. The only significant adverse effect by malathion could be demonstrated on the swimming velocity of cells in short-term experiments. The adverse effects of the pesticides were more pronounced during short-term than during long-term exposure. PMID:21562839

Azizullah, Azizullah; Richter, Peter; Häder, Donat-Peter

2011-08-01

255

Screening Pesticides for Neuropathogenicity  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Pesticides are routinely screened in studies that follow specific guidelines for possible neuropathogenicity in laboratory animals. These tests will detect chemicals that are by themselves strong inducers of neuropathogenesis if the tested strain is susceptible relative to the time of administration and methodology of assessment. Organophosphate induced delayed neuropathy (OPIDN) is the only known human neurodegenerative disease associated with pesticides and the existing...

Doherty, John D.

2006-01-01

256

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

Science.gov (United States)

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

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

2012-10-19

257

[Pesticide detection in Costarican vegetables based on the inhibition of serum and erythrocytic human cholinesterases].  

Science.gov (United States)

A simple and low cost method able to detect the presence of pesticides, organophosphates and carbamates based on the inhibition of serum and erythrocytic cholinesterases, was used in lettuce (Lactuca sativa), cilantro (Coriandum santivum) and celery (Apium graveolens) obtained from the Ferias del Agricultor from Valle Central of Costa Rica. The percentage inhibition of cholinesterases is related to the presence of plaguicide in the vegetable. Thirteen percent of the analyzed samples were positive for plaguicides using serum cholinesterase and 33% for erythrocytic cholinesterase. Washing and cooking the vegetables does not eliminate the presence of plaguicides but they lower slightly the concentration. Statistical evidence (p = 0.0001) indicates that erythrocytic cholinesterase has higher analytical sensitivity than serum cholinesterase. It is very important to establish the degree of contamination with pesticides in these agricultural products because they are exposed to direct contamination by fumigation, soil contamination and irrigation water, and are products that are often consumed without adequate cooking and washing. PMID:15969271

Nevermann, Karl Schosinsky; Guzmán, Eugenia Quintana

2004-12-01

258

Biochemical response to toxic effects of nudrin pesticide in male rats  

International Nuclear Information System (INIS)

The present study was carried out to investigate the effect of daily oral administrations of 4 mg /kg of the carbamate pesticide nudrin for 28 days on acetylcholine esterase activity in brain and serum, white blood cells (WBCs), red blood cells (RBCs), blood hemoglobin (Hb) and hematocrit (Hct) levels. Also, its effect on the metabolism of14C-glucose has been also studied. The results obtained demonstrated that nudrin is an acetylcholine esterase inhibitor in both brain and serum. Also, the pesticide induced significant increase in white blood cells and significant decrease in red blood cells, hemoglobin and hematocrit values all over the experimental period. Reduction in the metabolism of14C-glucose was also observed

2004-01-01

259

Brazilian vodkas have undetectable levels of ethyl carbamate  

Scientific Electronic Library Online (English)

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

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

260

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)

2008-05-05

 
 
 
 
261

77 FR 38285 - Pesticide Products; Registration Applications  

Science.gov (United States)

...Pesticide Products; Registration...register pesticide products containing...the Federal Insecticide, Fungicide...77042-2823. Product name: SeaCide...Biochemical insecticide/miticide...protection, Pesticides and...

2012-06-27

262

75 FR 4383 - Pesticide Products: Registration Applications  

Science.gov (United States)

...Pesticide Products: Registration...register pesticide products containing...the Federal Insecticide, Fungicide...92507. Product name: SPLAT...ingredients: Insecticide and (Z...protection, Pesticides and...

2010-01-27

263

77 FR 58045 - Clopyralid; Pesticide Tolerances  

Science.gov (United States)

...residential handlers and short-term...epa.gov/pesticides/trac/science...available in The Pesticide Analytical...standards and agricultural practices...procedure, Agricultural commodities, Pesticides and...

2012-09-19

264

78 FR 33731 - Propamocarb; Pesticide Tolerances  

Science.gov (United States)

...residential handler exposures...epa.gov/pesticides/trac/science...found in the Pesticide Analytical Method...standards and agricultural practices...procedure, Agricultural commodities, Pesticides and...

2013-06-05

265

Carbamates, Atropine, and Diazepam: Effects on Performance in the Running Rat,  

Science.gov (United States)

The authors have reported that when rats (500 g, male) are exercised to exhaustion on a treadmill, pretreatment with the centrally acting carbamate physostigmine reduced endurance (run time, RT) an increased the rate of rise of core temperature (Tc+). Bot...

C. B. Matthew R. W. Hubbard R. P. Francesconi G. J. Thomas

1987-01-01

266

Binary Antidotes for Organophosphate Poisoning: Aprophen Analogs That are Both Antimuscarinics and Carbamates.  

Science.gov (United States)

Prophylaxis against organophosphate poisoning can be achieved by pretreatment with physostigmine or pyridostigmine, which are carbamates, and aprophen, which is an anticholinergic agent. Thus, a series of aprophen analogues was synthesized with carbamyl s...

H. Leader R. M. Smejkal C. S. Payne F. N. Padilla B. P. Doctor

1989-01-01

267

Crystal Structures of Carbamate Kinase from Giardia lamblia Bound with Citric Acid and AMP-PNP  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The parasite Giardia lamblia utilizes the L-arginine dihydrolase pathway to generate ATP from L-arginine. Carbamate kinase (CK) catalyzes the last step in this pathway, converting ADP and carbamoyl phosphate to ATP and ammonium carbamate. Because the L-arginine pathway is essential for G. lamblia survival and absent in high eukaryotes including humans, the enzyme is a potential target for drug development. We have determined two crystal structures of G. lamblia CK (glCK) with bound ligands. O...

Lim, Kap; Kulakova, Liudmila; Galkin, Andrey; Herzberg, Osnat

2013-01-01

268

Carbolithiation of N-alkenyl ureas and N-alkenyl carbamates  

Digital Repository Infrastructure Vision for European Research (DRIVER)

N-Alkenyl ureas and N-alkenyl carbamates, like other N-acyl enamines, are typically nucleophilic at their ?-carbon. However, by incorporating an ?-aryl substituent, we show that they will also undergo attack at the ?-carbon by organolithium nucleophiles, leading to the products of carbolithiation. The carbolithiation of E and Z N-alkenyl ureas is diastereospecific, and N-tert-butoxycarbonyl N-alkenyl carbamates give carbol...

Julien Lefranc; Alberto Minassi; Jonathan Clayden

2013-01-01

269

Pesticides And Farmer Health In Nicaragua: A Willingness To Pay Approach  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This study presents an economic valuation of health risks of pesticides among Nicaraguan vegetable farmers. A comprehensive valuation of market and non-market value components of human health is established through farmers? willingness to pay (WTP) for low toxicity pesticides. Results show, that farmers are willing to spend about 28% of current pesticide expenditure for avoiding health risks. The validity of results is established in scope tests and a two-step regression model. WTP depends on...

Waibel, Hermann; Garming, Hildegard

2007-01-01

270

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

271

Health effects of pesticides  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

272

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) < 20 for repeatability and reproducibility, showing good accuracy and precision of the method. Aldicarb partially degraded in aldicarb sulphoxide during the analytical procedure, giving anomalous values. The LOQ for all 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

273

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

International Nuclear Information System (INIS)

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

2010-01-01

274

Pesticide selection pressure on Anopheles subpictus in Sri Lanka: comparison with two other Sri Lankan anophelines.  

Science.gov (United States)

Adult Anopheles subpictus from Sri Lanka show a broad spectrum of resistance towards organophosphate insecticides but not to carbamates in contrast to the broad resistance to organophosphates and carbamates reported earlier for An. nigerrimus. In both species the frequency of resistance to malathion and fenitrothion increased between 1980 and 1987, despite the ban on agricultural use of these two compounds and the restriction of malathion to indoor residual spraying in malaria control since 1977. In contrast, An. culicifacies shows only low level specific resistance to malathion at a very low frequency. As An. subpictus breeds to a large extent in paddy fields which are highly contaminated by agricultural pesticides, and is highly endophilic, selection for resistance theoretically could occur through both agricultural and anti-malarial pesticide use. However, the anti-malarial use of malathion may have been less important, taking into consideration the low level of resistance of An. culicifacies which is also highly endophilic but breeds to a negligible extent in paddy fields. PMID:2617615

Herath, P R; Joshi, G P

1989-01-01

275

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

276

Introduction to Indoor Air Quality: Pesticides  

Science.gov (United States)

... Pesticides An Introduction to Indoor Air Quality (IAQ) Pesticides Basic Information on Pollutants and Sources of Indoor ... Pest Control and Pesticide Safety (PDF) . Sources of Pesticides Products used to kill household pests (insecticides, termiticides, ...

277

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

278

Metolachlor: Pesticide Registration Standards.  

Science.gov (United States)

A comprehensive statement of the Agency's regulatory position on all pesticide products containing the same active ingredient. The document, which discusses metolachlor, describes the data upon which the regulatory position is based, provides the rational...

1980-01-01

279

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.

280

Farmers and Pesticides  

Science.gov (United States)

Modern pesticides have helped make farming far more productive. But they've also caused countless accidental poisonings. Now, a new study suggests that even the routine use of pesticides can pose serious health risks in the long run.This Science Update also contains in text format details of the research, which leads to these findings presented in the Science Update podcast. It also offers links to the other podcasts topics and resources for further inquiry.

American Association for the Advancement of Science (;)

2006-05-23

 
 
 
 
281

Inventory of pesticide emissions into the air in Europe  

Science.gov (United States)

Creation of a reliable and comprehensive emission inventory of the pesticides used in Europe is a key step towards quantitatively assessing the link between actual pesticide exposure and adverse health effects. An inventory of pesticide emissions was generated at a 1 × 1 km grid, for the year 2000. The emission model comprises three components: estimates of active substance (AS) wind drift taking into account crop type, volatilization during pesticide application and volatilization from the crop canopy. Results show that atmospheric emission of pesticides varies significantly across Europe. Different pesticide families are emitted from different parts of Europe as a function of the main crop(s) cultivated, agro-climatic conditions and production intensity. The pesticide emission inventory methodology developed herein is a valuable tool for assessing air quality in rural and peri-urban Europe, furnishing the necessary input for atmospheric modelling at different scales. Its estimates have been tested using global sensitivity and Monte Carlo analysis for uncertainty assessment and they have been validated against national and local surveys in four European countries; the results demonstrate the robustness and reliability of the inventory. The latter may therefore be readily used for exposure and health risk assessment studies targeting farmers, applicators, but also bystanders and the general population in Europe.

Sarigiannis, D. A.; Kontoroupis, P.; Solomou, E. S.; Nikolaki, S.; Karabelas, A. J.

2013-08-01

282

Modelling leaching of pesticides  

Energy Technology Data Exchange (ETDEWEB)

In Denmark 99% of the drinking water is derived from groundwater. This implies that efforts towards improved groundwater protection has high priority among the Danish authorities. Recent findings of pesticides in drinking water supply wells, in streams and in shallow groundwater have set focus on the methods and assumptions used for pesticide registration by the Danish Environmental Protection Agency. In particular, the appearance of phenoxy acids in many well boreholes from a few meters up to 80 meters below the soil surface, and in the aquifers below thick moraine clay layers has cast doubt on the applicability of the registration procedure. Very little is known about the rate of degradation occurring in the deeper saturated zone, though it is expected to be negligible for most pesticides due to the anoxic conditions present in this area. Another aspect influencing the risk of pesticide leaching is the time varying interactions between the pesticide properties and the hydrological conditions. Pesticides possessing a combination of properties which is expected to minimize the risk of leaching under conditions characteristic for spring application, may perform totally different if applied during the autumn. (EG) (36 refs.)

Villholth, K. [Water quality Inst., ATV (Denmark); Styczen, M.; Thorsen, M. [Danish Hydralic Inst., ATV (Denmark)

1995-07-01

283

Biomarkers of sensitivity and exposure in Washington state pesticide handlers.  

Science.gov (United States)

Organophosphate (OP) and N-methyl-carbamate (CB) insecticides are widely used in agriculture in the US and abroad. These compounds - which inhibit acetylcholinestersase (AChE) enzyme activity - continue to be responsible for a high proportion of pesticide poisonings among US agricultural workers. It is possible that some individuals may be especially susceptible to health effects related to OP/CB exposure. The paraoxonase (PON1) enzyme metabolizes the highly toxic oxon forms of some OPs, and an individual's PON1 status may be an important determinant of his or her sensitivity to these chemicals. This chapter discusses methods used to characterize the PON1 status of individuals and reviews previous epidemiologic studies that have evaluated PON1-related sensitivity to OPs in relation to various health endpoints. It also describes an ongoing longitudinal study among OP-exposed agricultural pesticide handlers who are participating in a recently implemented cholinesterase monitoring program in Washington State. This study will evaluate handlers' PON1 status as a hypothesized determinant of butyrylcholinesterase (BuChE) inhibition. Such studies will be useful to determine how regulatory risk assessments might account for differences in PON1-related OP sensitivity when characterizing inter-individual variability in risk related to OP exposure. Recent work assessing newer and more sensitive biomarkers of OP exposure is also discussed briefly in this chapter. PMID:20221867

Hofmann, Jonathan N; Keifer, Matthew C; Checkoway, Harvey; De Roos, Anneclaire J; Farin, Federico M; Fenske, Richard A; Richter, Rebecca J; van Belle, Gerald; Furlong, Clement E

2010-01-01

284

Pesticide resistance mechanisms produced by field selection pressures on Anopheles nigerrimus and A. culicifacies in Sri Lanka.  

Science.gov (United States)

In Sri Lanka, Anopheles nigerrimus is resistant to a range of organophosphate and carbamate insecticides at both the larval and adult stages. Biochemical studies indicate that an alteration in acetylcholinesterase is the basis of resistance rather than increased metabolic breakdown of the insecticides. In contrast, A. culicifacies is resistant only to malathion and closely related compounds containing a carboxylate ester bond. Agricultural pesticides are the sole source of selection pressure for resistance in A. nigerrimus, while in A. culicifacies pressure arises predominantly from antimalarial spraying. PMID:3492309

Hemingway, J; Jayawardena, K G; Herath, P R

1986-01-01

285

Computer-assisted prediction of pesticide substructure using mass spectra.  

Science.gov (United States)

Mass spectral classifiers of 16 substructures that are present in basic structures of pesticides have been investigated to assist pesticide residues analysis as well as screening of pesticide lead compounds. Mass spectral data are first transformed into 396 features, and then Genetic Algorithm-Partial Least Squares (GA-PLS) as a feature selection method and Support Vector Machine (SVM) as a validation method are implemented together to get an optimization feature set for each substructure. At last, a statistical method which is AdaBoost algorithm combined with Classification and Regression Tree (AdaBoost-CART) is trained to predict the 16 substructures presence/absence using the optimization mass spectral feature set. It is demonstrated that the optimum feature sets can be used to predict the 16 pesticide substructures presence/absence with mostly 85-100% in recognition success rate instead of the original 396 features. PMID:17543608

Xiong, Qing; Zhang, Yuxi; Li, Menglong

2007-06-19

286

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

287

[Pesticide poisoning in Moroccan children: epidemiological and prognostic aspects (1990-2008)].  

Science.gov (United States)

Objective: The purpose of this paper is to describe the epidemiological profile of acute pesticide poisoning in children (APP) treated by the Moroccan Poison Control Center (CAPM) and to analyze death cases in order to determine factors predictive of severity. Method: the study is based on a retrospective study of all cases of APP collected by the CAPM over a period of eighteen years (January 1990 to December 2008). Univariate analysis was performed to identify risk factors. Results: 2,672 cases of childhood poisoning by pesticide were collected. The mean age was 5.6 ± 4.57 years. The sex ratio was 1.12. The cause of poisoning was accidental in 87.1% of cases, followed by attempted suicide (12.1%). Organophosphates were the most frequent poison (50.7%), followed by alpha-chloralose (26.5%). The case fatality rate was 3.3%. Mortality was attributed to organophosphates in 30 cases, followed by inorganic derivatives (7 cases) and carbamates (6 cases). A univariate analysis comparing survivors and groups who died showed that rural origin (p = 0.04), voluntary circumstances (p = 0.001), and the type of chemical class of pesticide (p < 0.001) significantly influence fatal poisoning. Conclusion: Acute pesticide poisoning among children is a reality in Morocco. Preventive measures may be needed. PMID:21896214

Achour, Sanae; Khattabi, Asmae; Rhalem, Naïma; Ouammi, Lahcen; Mokhtari, Abdelrhani; Soulaymani, Abdelmajid; Bencheikh, Rachida Soulaymani

2011-01-01

288

Data on some pesticides concentrations in soils from southern part of Pardina polder  

Directory of Open Access Journals (Sweden)

Full Text Available The paper presents some aspects of pesticides concentration in the soils from southern part of Pardina polder. Values of pesticide-oncentrations are compared with values valid in case of the normal limit, alert limit and take action limit. These pesticides were introduced into soil because the change in land use (and land cover, the former wetlands being transformed into arable land. Pesticides were currently used in order to obtain higher crop productions, by controlling the development of various wild plants and insects.

MIERL? Marian

2007-10-01

289

Ethyl carbamate levels resulting from azodicarbonamide use in bread.  

Science.gov (United States)

Azodicarbonamide (ADA), a dough conditioner, is an additive approved in the US up to a maximum of 45 mg/kg in flour. The addition of 45 mg/kg of ADA was investigated and found to increase the ethyl carbamate (EC) content of commercially prepared breads by 1-3 micrograms/kg. A similar increase in EC was observed in breads baked in the laboratory with a bread machine. The increase in EC levels appears to depend on a variety of factors, most notably the concentration of ADA added and the time of fermentation. The addition of 20 mg/kg ADA caused only a slight increase, if any, in commercial products but a 2.3 micrograms/kg increase of EC in breads baked with a bread machine. When 100 mg/kg of ascorbic acid was added along with ADA, smaller EC increases were observed. Addition of urea was also found to enhance the EC content of the bread. Toasting, which was previously shown to increase EC levels, caused even larger increases when ADA or urea had been added. PMID:9059587

Cañas, B J; Diachenko, G W; Nyman, P J

1997-01-01

290

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 620nM, 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 570nM against MDA-MB-435 melanoma and MDA-MB-468 breast cancer cell lines, respectively. Analog 6e had GI50 values of 650 and 900nM 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

291

Pesticide Fact Sheet: Canola Oil.  

Science.gov (United States)

This document contains up-to-date chemical information, including a summary of the Agency's regulatory position and rationale, on a specific pesticide or group of pesticides. A Fact Sheet is issued after Registration of a new chemical.

1998-01-01

292

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

International Nuclear Information System (INIS)

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

2013-02-01

293

Pesticide exposure--Indian scene.  

Science.gov (United States)

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 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. PMID:15138033

Gupta, P K

2004-05-20

294

On the paradox of pesticides  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 pest...

Li, Y. Charles; Yang, Yipeng

2013-01-01

295

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

Science.gov (United States)

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

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

2009-11-01

296

Decontaminating pesticide protective clothing.  

Science.gov (United States)

The review of recent work on the mechanisms of soil removal from textiles assists in understanding decontamination of pesticide protective clothing. The current work provides explanatory conclusions about residue retention as a basis of making recommendations for the most effective decontamination procedures. A caution about generalizations: Some pesticides produce very idiosyncratic responses to decontamination. An example is the paraquat/salt response. Other pesticides exhibit noticeable and unique responses to a highly alkaline medium (carbaryl), or to bleach (chlorpyrifos), or are quickly volatilized (methyl parathion). Responses such as these do not apply to other pesticides undergoing decontamination. Given this caution, there are soil, substrate, and solvent responses that do maximize residue removal. Residue removal is less complete as the concentration of pesticide increases. The concentration of pesticide in fabric builds with successive exposures, and the more concentrated the pesticide, the more difficult the removal. Use a prewash product and/or presoak. The surfactant and/or solvent in a prewash product is a booster in residue removal. Residues transfer from contaminated clothing to other clothing during the washing cycle. Use a full washer of water for a limited number of garments to increase residue removal. The hotter the washing temperature, the better. Generally, this means a water temperature of at least 49 degrees C, and preferably 60 degrees C. Select the detergent shown to be more effective for the formulation: heavy-duty liquid detergents for emulsifiable concentrate formulations and powdered phosphate detergents for wettable powder formulations. If the fabric has a soil-repellent finish, use 1.25 times the amount recommended on the detergent label. For water hardness above 300 ppm, an additional amount of powdered phosphate detergent is needed to obtain the same level of residue removal as obtained with the heavy-duty liquid detergent when laundering fabrics with the soil-repellent finish. The mechanical action of agitation increases dislodgement of particulate material. Too many items in the washing apparatus or too low water volume, or both, decrease agitation and soil removal. Bleach can be used if desired. Fabric softener does not affect pesticide absorption or residue removal in laundering. Dry cleaning is not recommended because the solvents used in dry cleaning may be recycled through dilution, filtration, activated charcoal adsorption, or distillation. Pesticides still may be present in recycled solvents and can be transferred from one item to another, or from one load to subsequent loads of dry cleaning. PMID:8419989

Laughlin, J

1993-01-01

297

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

298

Enantioselective Transformation of Allyl Carbonates into Branched Allyl Carbamates by Using Amines and Recycling CO2 under Iridium Catalysis.  

Science.gov (United States)

Enantioselective transformation of allyl carbonates into branched allyl carbamates by using amines and recycling CO2 in the presence of an Ir complex and K3 PO4 was accomplished. This provided branched allyl carbamates in fair to excellent yields with up to 98:2 regioselectivity and 93?% ee. The role of CO2 in this transformation is discussed as well. PMID:24839012

Zheng, Sheng-Cai; Zhang, Min; Zhao, Xiao-Ming

2014-06-10

299

Ultrastructural changes in the digestive tract of Deroceras reticulatum (Müller) induced by a carbamate molluscicides and by metaldehyde  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Electron microscope investigations reveal different reactions of cells in the digestive tract of Deroceras reticulatum to intoxication with carbamate or metaldehyde molluscicides. All enterocytes are more strongly attacked by the carbamate compound Mesurol than by metaldehyde. The better efficiency of Mesurol is primarily attributed to its severe impact on nuclei, leading to other cell damage and finally to an increased macrophage reaction.

Triebskorn, R.

1989-01-01

300

New synthesis of carbamate, thiocarbamate and urea type herbicides: preparation of "1"4C-labelled diuron and EPTC  

International Nuclear Information System (INIS)

N,N-dialkyl-carbamic acid-trimethylsilyl-esters were synthesized starting with "1"4CO_2. The new synthesis route is simple and provides good radiochemical yield. Silyl-carbaminates directly or through carbamoyl-halogenides may be used for preparation of labelled herbicides: carbamates, thiocarbamates and ureas. (author)

1981-01-01

 
 
 
 
301

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.

Prado-Ochoa, Maria Guadalupe; Gutierrez-Amezquita, Ricardo Alfonso; Abrego-Reyes, Victor Hugo; Velazquez-Sanchez, Ana Maria; Munoz-Guzman, Marco Antonio; Ramirez-Noguera, Patricia; Angeles, Enrique; Alba-Hurtado, Fernando

2014-01-01

302

Pesticide Action Network UK  

Science.gov (United States)

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

303

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

304

Synthesis and anti-HIV properties of new carbamate prodrugs of AZT.  

Science.gov (United States)

A series of new 5'-O-carbamate prodrugs of AZT have been prepared. The stability in biological media, anti-HIV properties and pharmacokinetic parameters in dogs were evaluated. The compounds display moderate anti-HIV activity in cell culture. After oral administration of carbamate IV in dogs, both intact prodrug IV and released AZT were discovered in dog blood. Pharmacokinetic parameters of the compound IV were estimated. Half-life (T(1/2)) of AZT released after oral administration of IV in dogs was close to that after administration of AZT itself, and time to the maximum concentration (T(max)) of AZT released from IV was two and three times longer compared with that of AZT and H-phosphonate AZT, respectively. Acute toxicity was more than five times less if compared with AZT. As a result, we consider this series of carbamate derivatives of AZT as perspective for development of anti-HIV agents. PMID:22958368

Solyev, Pavel N; Shipitsin, Alexander V; Karpenko, Inna L; Nosik, Dmitry N; Kalnina, Ludmila B; Kochetkov, Sergey N; Kukhanova, Marina K; Jasko, Maxim V

2012-12-01

305

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

Science.gov (United States)

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

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

2013-12-01

306

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 0.2ng/g and 200ng/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 480ng/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 344ng/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

307

Inhibition of carbonic anhydrases I and II by N-unsubstituted carbamate esters.  

Science.gov (United States)

We previously showed that the zinc metalloenzyme carbonic anhydrases (CA I and II isozymes) bind "neutral" amides and related compounds as anions through coordination of their deprotonated amide nitrogen to the active site zinc (Rogers, J. I., Mukherjee, J., and Khalifah, R. G. (1987) Biochemistry 26, 5672-5679). Urethan, the ethyl carbamate ester, was among such compounds. The present study was designed to test whether other N-unsubstituted carbamate esters of pharmacological interest (as sedatives, hypnotics, anxiolytics, and skeletal muscle relaxants) were capable of binding to CA in the same manner. We studied the interaction of human CA I and II with urethan, phenyl carbamate, ethinamate, meprobamate, and methocarbamol. Phenyl carbamate studies were greatly complicated by its uncatalyzed hydrolysis via an elimination mechanism to form cyanate, a powerful CA inhibitor. In general, the compounds display: 1) slow on-off inhibition binding kinetics in the seconds range, 2) maximal inhibitor affinity at alkaline pH, and 3) characteristic three-band visible spectra of their complexes with cobalt-substituted CA I. These properties are shared with the previously studied amide inhibitors and are taken as evidence that the deprotonated carbamate nitrogen coordinates to the active site metal ion. CA I appeared to bind carbamate esters more tightly than CA II, an unusual 1000-fold selectivity being seen in the case of methocarbamol. The inhibition by these drugs is not sufficiently strong to implicate CA I and II in their mechanism of action. However, it does suggest the possible existence of previously unsuspected similarities between binding to CA and to their physiological receptors or targets, particularly the involvement of zinc. PMID:1460006

Parr, J S; Khalifah, R G

1992-12-15

308

Pesticides and Eggshell Thinning  

Science.gov (United States)

This lab activity is about toxic substances like pesticides and their effects on biological systems. The activity starts with an introduction of how birds sequester calcium to make an egg. Learners are asked to bring eggshells from home from different kinds of birds, if possible. These shells are prepared for analysis. Learners discover how to prepare a primary acid, neutralize a base, and calculate the percentage of CaCO3 in shell material. These results lead to a discussion of how calcium moves through this biochemical system and how a pesticide can prevent calcium from building eggshell. This resource includes tips, some related to safety; adult supervision recommended.

Tucker, David

2009-01-01

309

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

310

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

International Nuclear Information System (INIS)

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

2012-11-01

311

Pesticides and Mosquito Control  

Science.gov (United States)

This factsheet from the Environmental Protection Agency includes several summary documents on the problem of mosquito-borne diseases and the pesticides used to control mosquitoes. The resources cover issues from mosquito biology through the EPA's recent findings on the negative health impacts of Malathion.

312

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

Science.gov (United States)

The nuclear receptor, pregnane X receptor (PXR), is a ligand-dependent transcription factor that regulates genes involved in xenobiotic metabolism. Recent studies have shown that PXR activation may affect energy metabolism as well as the endocrine and immune systems. In this study, we characterized and compared the agonistic activities of a variety of pesticides against human PXR (hPXR) and mouse PXR (mPXR). We tested the hPXR and mPXR agonistic activity of 200 pesticides (29 organochlorines, 11 diphenyl ethers, 56 organophosphorus pesticides, 12 pyrethroids, 22 carbamates, 12 acid amides, 7 triazines, 7 ureas, and 44 others) by reporter gene assays using COS-7 simian kidney cells. Of the 200 pesticides tested, 106 and 93 activated hPXR and mPXR, respectively, and a total of 111 had hPXR and/or mPXR agonistic activity with greater or lesser inter-species differences. Although all of the pyrethroids and most of the organochlorines and acid amides acted as PXR agonists, a wide range of pesticides with diverse structures also showed hPXR and/or mPXR agonistic activity. Among the 200 pesticides, pyributicarb, pretilachlor, piperophos and butamifos for hPXR, and phosalone, prochloraz, pendimethalin, and butamifos for mPXR, acted as particularly potent activators at low concentrations in the order of 10??-10?? M. In addition, we found that several organophosphorus oxon- and pyributicarb oxon-metabolites decreased PXR activation potency compared to their parent compounds. These results suggest that a large number of structurally diverse pesticides and their metabolites possess PXR-mediated transcriptional activity, and their ability to do so varies in a species-dependent manner in humans and mice. PMID:21115097

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

2011-02-27

313

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.

2011-02-27

314

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

315

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

Science.gov (United States)

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

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

2012-07-01

316

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

Scientific Electronic Library Online (English)

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

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

317

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

Scientific Electronic Library Online (English)

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

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

318

X-ray structure and characterization of carbamate kinase from the human parasite Giardia lamblia  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The three-dimensional structure of carbamate kinase from the human parasite G. lamblia has been determined at 3?Å resolution. Steady-state kinetic parameters have been determined and dsRNA-silencing experiments indicate that the enzyme is essential for the survival of G. lamblia.

Galkin, Andrey; Kulakova, Liudmila; Wu, Rui; Nash, Theodore E.; Dunaway-mariano, Debra; Herzberg, Osnat

2010-01-01

319

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[double bond, length as m-dash]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 (?EB) 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-HLi(+) 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 ?GB results. PMID:24914737

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

2014-07-21

320

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

Science.gov (United States)

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

 
 
 
 
321

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

Science.gov (United States)

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

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

2013-10-01

322

75 FR 11174 - Pesticide Product Registration Approval  

Science.gov (United States)

...FRL-8802-1] Pesticide Product Registration Approval...5) of the Federal Insecticide, Fungicide, and...registration for the pesticide product Gonacon Immunocontraceptive...to register the pesticide product, Gonacon...

2010-03-10

323

75 FR 8939 - Pesticide Products; Registration Applications  

Science.gov (United States)

...register pesticide products containing an...previously registered pesticide products. Pursuant to...the Federal Insecticide, Fungicide...register three new pesticide products containing the...acid derivative insecticide - under...

2010-02-26

324

77 FR 6560 - Pesticide Product Registration Approval  

Science.gov (United States)

...FRL-9334-8] Pesticide Product Registration Approval...to register the pesticide product Contram ST-1...previously registered products pursuant to the...of the Federal Insecticide, Fungicide, and...Division, Office of Pesticide Programs,...

2012-02-08

325

Effects of Urbanization on Water Quality: Pesticides  

Science.gov (United States)

... page The effects of urbanization on water quality: Pesticides Pesticides are chemical and biological substances intended to control pests, such as insects, weeds, bacteria, and algae. Pesticides are heavily used on farmland, but in urban ...

326

pesticides workshop presentation niea ray thomas  

...Pesticides – Every Drop Counts Ray Thomas...to act synergistically with other pesticides or environmental pollutants. • Throughout the...detected in combination with other pesticides and pollutants at the same...

327

78 FR 49932 - Emamectin; Pesticide Tolerance  

Science.gov (United States)

...exposure to the pesticide chemical residue, including all anticipated...children to the pesticide chemical residue in establishing a tolerance...exposure to the pesticide chemical residue . . . .'' Consistent with...mediated neurotoxicity is a solid hypothesis, data...

2013-08-16

328

78 FR 25396 - Glyphosate; Pesticide Tolerances  

Science.gov (United States)

...htm. Based on the Pesticide Root Zone Model...glyphosate (residential handlers). However, since...www.epa.gov/pesticides/trac/science...practice and procedure, Agricultural commodities, Pesticides and pests,...

2013-05-01

329

78 FR 49927 - Imazapic; Pesticide Tolerances  

Science.gov (United States)

...aggregate exposure to the pesticide chemical residue...potential for repeated handler inhalation exposure...of Concern Once a pesticide's toxicological...practice and procedure, Agricultural commodities, Pesticides and pests,...

2013-08-16

330

77 FR 40806 - Methoxyfenozide; Pesticide Tolerances  

Science.gov (United States)

...action if you are an agricultural producer, food manufacturer, or pesticide manufacturer. Potentially...ornamentals. Residential pesticide handlers may be exposed for...practice and procedure, Agricultural commodities, Pesticides and pests,...

2012-07-11

331

77 FR 67771 - Flonicamid; Pesticide Tolerances  

Science.gov (United States)

...TFNG-AM. Based on the Pesticide Root Zone Model...Therefore, residential handler scenarios are not...www.epa.gov/pesticides/trac/science...practice and procedure, Agricultural commodities, Pesticides and pests,...

2012-11-14

332

77 FR 73951 - Pyriproxyfen; Pesticide Tolerances  

Science.gov (United States)

...water models used in pesticide exposure assessment...short-term residential handler dermal and inhalation...www.epa.gov/pesticides/trac/science...practice and procedure, Agricultural commodities, Pesticides and pests,...

2012-12-12

333

75 FR 22245 - Imidacloprid; Pesticide Tolerances  

Science.gov (United States)

...assumption that residential pesticide handlers (i.e., persons who...data in some cases and Pesticide Handler Exposure Database (PHED...practice and procedure, Agricultural commodities, Pesticides and pests, Reporting...

2010-04-28

334

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

335

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

336

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.)

1979-01-01

337

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

International Nuclear Information System (INIS)

ry allergic parameters. BRP and furathiocarb induced marked proliferation of MHC Class II-positive B-cells and Th1 cytokines (IL-2, TNF-?, and IFN-?) in only auricular LN cells. These results suggest that 2,4-D is a respiratory allergen and BRP and furathiocarb are contact allergens. As our protocol detected classified allergic responses to low-molecular-weight chemicals, it thus may be useful for detecting environmental chemical-related allergy.

2009-07-10

338

Electron-impact promoted fragmentation of alkyl-n-/1-phenylethyl/-carbamates of primary, secondary and tertiary alcohols.  

Science.gov (United States)

The mass spectra of twenty alkyl carbamates derived from primary, secondary, and tertiary alcohols are investigated, using deuterium labeling and high-resolution mass spectrometry. Several of the primary and secondary alcohol derivatives are found to yield an ion formally equivalent to the product ion of a McLafferty rearrangement. Deuterium labeling, however, revealed a lack, in these carbamate derivatives, of the usual site specificity associated with the McLafferty rearrangement. A double hydrogen rearrangement process was observed in the mass spectra of several carbamates derived from tertiary alcohols.

Pereira, W. E.; Halpern, B.; Solomon, D. D.; Duffield, A. M.

1971-01-01

339

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

340

75 FR 69353 - Isoxaben; Pesticide Tolerances  

Science.gov (United States)

...e., residential handler exposure). There is...in areas adjacent to pesticide applications. For residential handlers, dermal and inhalation...practice and procedure, Agricultural commodities, Pesticides and pests,...

2010-11-12

 
 
 
 
341

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

342

Pesticides residues in water treatment plant sludge: validation of analytical methodology using liquid chromatography coupled to Tandem mass spectrometry (LC-MS/MS); Residuos de agrotoxicos em lodo de estacao de tratamento de agua: validacao de metodologia analitica utilizando cromatografia liquida acoplada a espectrometria de massas em Tandem (LC-MS/MS)  

Energy Technology Data Exchange (ETDEWEB)

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)

Moracci, Luiz Fernando Soares

2008-07-01

343

Tracer work in pesticide research  

International Nuclear Information System (INIS)

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

1989-02-28

344

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

Science.gov (United States)

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

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

2001-01-01

345

CYP1/2 Activation and Glutathione-dependent Cytotoxicity of Four Pesticides in Hep G2 and Fa32 Cells.  

Science.gov (United States)

The cytotoxicity of the carbamate insecticide carbaryl, the organophosphate insecticide quinalphos, the benzimidazole fungicide benomyl, and its debutylcarbamoylated derivative carbendazim was investigated in rat (Fa32) and human (Hep G2) hepatoma-derived established cell lines. Benomyl was the most toxic of the four pesticides, followed by quinalphos, carbaryl and the least toxic carbendazim, suggesting that the butylcarbamoyl group plays an important role in the toxicity of benomyl. EROD (7-ethoxyresorufin-O-deethylase) and PROD (7-pentoxyresorufin-O-depentylase) activity were moderately activated in Fa32 cells. In Hep G2 cells no PROD was measured, but EROD was activated 2.5 to 28 times the control values. Piperonyl butoxide and 1-aminobenzotriazole did not influence the cytotoxicity of the pesticides. However, when the endogenous glutathione content was reduced by pretreatment of the cells with l-buthionine-S,R-sulfoximine, the cytotoxicity of the pesticides strongly increased in both cell lines. In conclusion, the same cytotoxicity was observed for the four pesticides in both the animal and the human cell line. CYP1/2-dependent enzymes were activated to different degrees. No evidence was obtained for a cytochrome P450-dependent cytotoxicity, but glutathione showed a protective effect against the four pesticides in both cell lines. PMID:20654549

Dierickx, P J

1999-01-01

346

EPA Pesticide Fact Sheet: Propoxur.  

Science.gov (United States)

This document contains up-to-date chemical information, including a summary of the Agency's regulatory position and rationale, on a specific pesticide or group of pesticides. A Fact Sheet is issued after one of the following actions has occurred: Issuance...

1995-01-01

347

PESTICIDE REMOVAL BY MEMBRANE PROCESSES  

Science.gov (United States)

Approximately 21 billion pounds of pesticides have been applied to United States farmlands since 1964. n agricultural regions, high pesticide concentrations occur in surface and groundwaters because of spring runoff or leaching. ecause many of these compounds pose health risks, t...

348

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)

2008-01-01

349

Toxicity of pesticides to fish. Volume 1  

Energy Technology Data Exchange (ETDEWEB)

This book is the first major attempt to review comprehensively all available information on the environmental fate of pesticides and their acute and chronic effects to fish. Topics considered include pesticides in the environment, pesticide residues in fish, uptake and depuration of pesticide residues by fish, and toxicity test and test methodology.

Murty, A.S.

1986-01-01

350

Host-guest chemistry of cyclodextrin carbamates and cellulose derivatives in aqueous solution.  

Science.gov (United States)

Supramolecular polymer micelles were prepared on basis of the inclusion complexation between cyclodextrin carbamates and cellulose derivatives in aqueous media. Cyclodextrin carbamates were synthesized by microwave-assisted method from cyclodextrin and urea. The urea modified cyclodextrin shows the higher yield than the physical mixture of urea/cyclodextrin in the micellization with cellulose derivatives. The supramolecular structure of the core-shell micelles was demonstrated by (1)H NMR spectra, TEM images, and fluorescence spectra. The drug release behavior of the supramolecular polymer micelles was evaluated using prednisone acetate as a model drug. The drug loaded micelles showed steady and long time drug release behavior. With these properties, the supramolecular polymer micelles are attractive as drug carriers for pharmaceutical applications. PMID:23987437

Guo, Xin; Jia, Xiangxiang; Du, Jiaojiao; Xiao, Longqiang; Li, Feifei; Liao, Liqiong; Liu, Lijian

2013-10-15

351

40 CFR 152.175 - Pesticides classified for restricted use.  

Science.gov (United States)

...PROCEDURES Classification of Pesticides § 152.175 Pesticides classified for restricted... The following uses of pesticide products containing the active...phosphate and biological insecticides ......do...

2010-07-01

352

77 FR 26954 - 1-Naphthaleneacetic acid; Pesticide Tolerances  

Science.gov (United States)

...if you are an agricultural producer, food...manufacturer, or pesticide manufacturer...residential handler assessment...chronic dietary pesticide exposures are...procedure, Agricultural commodities, Pesticides and...

2012-05-08

353

A Homogenous Luminescence Assay Reveals Novel Inhibitors for Giardia Lamblia Carbamate Kinase  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The human pathogen Giardia lamblia is an anaerobic protozoan parasite that causes giardiasis, one of the most common diarrheal diseases worldwide. Although several drugs are available for the treatment of giardisis, resistance to these drugs has been reported and is likely to increase. The Giardia carbamate kinase (glCK) plays an essential role in Giardia metabolism and has no homologs in humans, making it an attractive candidate for anti-Giardia drug development. We have developed a luminesc...

Chen, Catherine Z.; Southall, Noel; Galkin, Andrey; Lim, Kap; Marugan, Juan J.; Kulakova, Liudmila; Shinn, Paul; Leer, Danielle; Zheng, Wei; Herzberg, Osnat

2012-01-01

354

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

355

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

356

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

This work deals with the preparation and chemical characterization of new Ultra-Small Iron-Oxide Superparamagnetic Nanoparticles (USPIONs) functionalized with Titanium-carbamate. The synthesis was performed starting from oleate-coated and 2-pyrrolidone-coated USPIONs having a maghemite (gamma-Fe2O3) and magnetite (Fe3O4) crystalline core, respectively. Zero-field-cooled (ZFC) and field-cooled (FC) magnetic susceptibility curves as well as the magnetization behavior as a function of temperatur...

Domenici V.; Dolci S.; Pampaloni G.; Jaglicic Z.

2012-01-01

357

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

Science.gov (United States)

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

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

2012-01-01

358

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

359

Environmental friendly slow-release pesticide formulations  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The present invention relates to a slow-release pesticide system in agragrian applications that includes but is not limited solely to insecticide, fungicide and herbicide formulations. The system includes a pesticide incorporated into vesicles that is formed by neutral lipids (thereby enhancing the water solubility of the pesticide). The vesicles that incorporate the pesticide are, in turn, adsorbed, on a clay mineral. The formulations are appropriate for pesticide molecules of any type (hydr...

Undabeytia Lo?pez, Toma?s; Maqueda Porras, Celia; Morillo Gonza?lez, Esmeralda; Sa?nchez Verdejo, Trinidad; Nir, Shlomo

2009-01-01

360

PESTICIDE EXPOSURE AND AMYOTROPHIC LATERAL SCLEROSIS  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Our objectives were to summarize literature on the association of amyotrophic lateral sclerosis (ALS) with pesticides as a group and to evaluate associations of ALS with specific pesticides. We conducted a meta-analysis of published studies of ALS and pesticides as a group and investigated the association of ALS with specific pesticides, using data from the Agricultural Health Study (AHS), a cohort including 84,739 private pesticide applicators and spouses. AHS participants provided informati...

Kamel, Freya; Umbach, David M.; Bedlack, Richard S.; Richards, Marie; Watson, Mary; Alavanja, Michael Cr; Blair, Aaron; Hoppin, Jane A.; Schmidt, Silke; Sandler, Dale P.

2012-01-01

 
 
 
 
361

X-ray structure and characterization of carbamate kinase from the human parasite Giardia lamblia.  

Science.gov (United States)

Carbamate kinase catalyzes the reversible conversion of carbamoyl phosphate and ADP to ATP and ammonium carbamate, which is hydrolyzed to ammonia and carbonate. The three-dimensional structure of carbamate kinase from the human parasite Giardia lamblia (glCK) has been determined at 3 A resolution. The crystals belonged to the monoclinic space group P2(1), with unit-cell parameters a = 69.77, b = 85.41, c = 102.1 A, beta = 106.8 degrees . The structure was refined to a final R factor of 0.227. The essentiality of glCK together with its absence in humans makes the enzyme an attractive candidate for anti-Giardia drug development. Steady-state kinetic rate constants have been determined. The k(cat) for ATP formation is 319 +/- 9 s(-1). The K(m) values for carbamoyl phosphate and ADP are 85 +/- 6 and 70 +/- 5 microM, respectively. The structure suggests that three invariant lysine residues (Lys131, Lys216 and Lys278) may be involved in the binding of substrates and phosphoryl transfer. The structure of glCK reveals that a glycerol molecule binds in the likely carbamoyl phosphate-binding site. PMID:20383005

Galkin, Andrey; Kulakova, Liudmila; Wu, Rui; Nash, Theodore E; Dunaway-Mariano, Debra; Herzberg, Osnat

2010-04-01

362

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

363

77 FR 23713 - Pesticides; Final Guidance on Material Safety Data Sheets as Pesticide Labeling; Request for...  

Science.gov (United States)

...EPA-HQ-OPP-2012-0176; FRL-9343-9] Pesticides; Final Guidance on Material Safety Data Sheets as Pesticide Labeling; Request for Comment on Paperwork...Agency is announcing the availability of a Pesticide Registration Notice (PR Notice)...

2012-04-20

364

76 FR 72404 - Pesticides: Availability of Pesticide Registration Notice Regarding the Non-Dietary Exposure Task...  

Science.gov (United States)

...EPA-HQ-OPP-2011-0877; FRL-9326-8] Pesticides: Availability of Pesticide Registration Notice Regarding the Non-Dietary...The Agency is announcing the availability of a Pesticide Registration Notice (PR Notice) regarding...

2011-11-23

365

75 FR 62323 - Pesticide Management and Disposal; Standards for Pesticide Containers and Containment; Change to...  

Science.gov (United States)

...EPA-HQ-OPP-2005-0327; FRL-8848-8] RIN 2070-AJ74 Pesticide Management and Disposal; Standards for Pesticide Containers and Containment; Change to Labeling...SUMMARY: EPA is amending the pesticide container and containment regulations...

2010-10-08

366

76 FR 21294 - Pesticides; Microbial Pesticide Definitions and Applicability; Clarification and Availability of...  

Science.gov (United States)

...EPA-HQ-OPP-2010-0670; FRL-8857-7] RIN 2070-AJ80 Pesticides; Microbial Pesticide Definitions and Applicability; Clarification...is also soliciting comment on a draft microbial pesticide test guideline, explaining the deposition...

2011-04-15

367

75 FR 33705 - Pesticide Management and Disposal; Standards for Pesticide Containers and Containment; Change to...  

Science.gov (United States)

...EPA-HQ-OPP-2005-0327; FRL-8830-7] RIN 2070-AJ74 Pesticide Management and Disposal; Standards for Pesticide Containers and Containment; Change to Labeling...SUMMARY: EPA is amending the pesticide container and containment regulations...

2010-06-15

368

Optimization of a multi-residue screening method for the determination of 85 pesticides in selected food matrices by stir bar sorptive extraction and thermal desorption GC-MS.  

Science.gov (United States)

A multi-residue method to determine 85 pesticides, including organochlorine pesticides, carbamates, organophosphorus pesticides, and pyrethroids, in vegetables, fruit, and green tea, has been developed. The method is based on stir bar sorptive extraction (SBSE) coupled to thermal desorption (TD) and retention time locked (RTL) GC-MS operating in the scan mode. Samples are extracted with methanol and diluted with water prior to SBSE. Dilution of the methanol extract before SBSE was optimized to obtain high sensitivity and to minimize adsorption onto the glass wall of the extraction vessel as well as to minimize sample matrix effects (particularly for the pesticides with high log K(o,w) values). The optimized method consists of a dual SBSE extraction performed simultaneously on respectively a twofold and a fivefold diluted methanol extract. After extraction, the two stir bars are placed in a single glass thermal desorption liner and are simultaneously desorbed. The method showed good linearity (r2 > 0.9900) and high sensitivity (limit of detection: < 5 microg kg(-1)) for most of the target pesticides. The method was applied to the determination of pesticides at low microg kg(-1) in tomato, cucumber, green soybeans, spinach, grapes, and green tea. PMID:16013835

Ochiai, Nobuo; Sasamoto, Kikuo; Kanda, Hirooki; Yamagami, Takashi; David, Frank; Tienpont, Bart; Sandra, Pat

2005-06-01

369

Pesticide use and application: An Indian scenario  

Energy Technology Data Exchange (ETDEWEB)

Agricultural development continues to remain the most important objective of Indian planning and policy. In the process of development of agriculture, pesticides have become an important tool as a plant protection agent for boosting food production. Further, pesticides play a significant role by keeping many dreadful diseases. However, exposure to pesticides both occupationally and environmentally causes a range of human health problems. It has been observed that the pesticides exposures are increasingly linked to immune suppression, hormone disruption, diminished intelligence, reproductive abnormalities and cancer. Currently, India is the largest producer of pesticides in Asia and ranks twelfth in the world for the use of pesticides. A vast majority of the population in India is engaged in agriculture and is therefore exposed to the pesticides used in agriculture. Although Indian average consumption of pesticide is far lower than many other developed economies, the problem of pesticide residue is very high in India. Pesticide residue in several crops has also affected the export of agricultural commodities in the last few years. In this context, pesticide safety, regulation of pesticide use, proper application technologies, and integrated pest management are some of the key strategies for minimizing human exposure to pesticides. There is a dearth of studies related to these issues in India. Therefore, the thrust of this paper was to review the technology of application of pesticides in India and recommend future strategies for the rational use of pesticides and minimizing the problems related to health and environment.

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

2009-06-15

370

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 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

1987-11-24

371

Evidence for genotoxicity of pesticides in pesticide applicators: a review.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A systematic review of the literature has been conducted and studies reporting investigations of genotoxicity biomarkers in pesticide workers have been assessed with view to establishing whether there was evidence for any risk to those using pesticides approved in the United Kingdom. Each of the studies was evaluated using a set of criteria drawn up by members of the UK Committee of Mutagenicity based upon the guidelines proposed by the International Programme on Chemical Safety (IPCS) workin...

Bull, S.; Fletcher, K.; Boobis, A. R.; Battershill, J. M.

2006-01-01

372

Multiresidue determination of pesticides and pesticide metabolites in soil  

Energy Technology Data Exchange (ETDEWEB)

Methods for the multiresidue extraction, cleanup and GC/MS determination of 142 pesticides and pesticide metabolites in soil have been developed. The use of solid phase extraction cartridges makes it possible to clean up the soil sufficiently so that the equivalent of 40 mg. soil may be injected onto the GC capillary column without overloading or harming the column. Combining this clean-up method with chemical ionization ion trap detection allowed for very low limits of detection.

Mogadati, P.S.; Rosen, J.D. [Rutgers Univ., New Brunswick, NJ (United States)

1995-12-31

373

Pesticide formulations and application systems  

Energy Technology Data Exchange (ETDEWEB)

This book discusses pesticide formulations; spraying techniques and/or low and ultra low volume applications employing oil carriers, including subsurface drip irrigation and plant growth regulators; and granule technology.

Kaneko; Spicer

1985-01-01

374

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

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese A crescente procura pela própolis tem ocasionado aumento em sua produção. Entretanto, uma agricultura cada vez mais dependente de pesticidas representa preocupação com relação à contaminação ambiental, além das abelhas e seus produtos. Neste sentido, a proposta do presente trabalho foi avaliar a pre [...] sença de pesticidas (organoclorados, organofosforados, piretroides, carbamatos, herbicidas, fungicidas e acaricidas) em amostras de própolis do Estado de São Paulo. Apicultores de diversas localidades do Estado forneceram amostras de própolis (50). Estas foram coletadas, armazenadas em sacos plásticos atóxicos e mantidas em freezer até as análises. Os possíveis resíduos de pesticidas foram analisados por cromatografia gasosa. Não foi observada a presença dos pesticidas analisados nas amostras. Neste caso, a própolis analisada no Estado de São Paulo não apresentou contaminação por pesticidas. Abstract in english The increasing demand for propolis has caused a raise in its production. However, an increasingly pesticide-dependent agriculture is a great concern with regard to bees, their produce and environmental contamination. Current analysis evaluates the presence of pesticides (organochlorines, organophosp [...] hates, pyrethroids, carbamates, herbicides, fungicides and acaricides) in samples of propolis from the state of São Paulo, Brazil. Beekeepers from several localities in the state provided samples of propolis (50), which were collected, stored in non-toxic plastic bags and maintained in a freezer for analyses. Possible pesticide residues were examined by gas chromatography method but no pesticide residues were detected in the examined propolis samples. Propolis analyzed in the state of São Paulo did not show any pesticide contamination.

Ricardo de Oliveira, Orsi; Lidia Maria Ruv Carelli, Barreto; Silvia Maria Alves, Gomes; Samir Moura, Kadri.

375

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

2001-01-01

376

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

377

Kombinationseffekter af pesticider  

DEFF Research Database (Denmark)

Resumé: Effekten af 101 tokomponentblandinger og 20 trekomponentblandinger bestående af 22 forskellige pesticider blev undersøgt i 7 forskellige testsystemer. Effekterne af blandingerne blev sammenholdt med pesticidernes virkningsmekanismer/virkemåder med henblik på at undersøge, om det med baggrund i denne viden var muligt prediktere, hvorvidt blandingerne ville udvise additivitet, antagonisme eller synergisme. Endvidere blev undersøgt i hvor vid udstrækning resultaterne fra et testsystem kunne overføres til andre testsystemer. Hovedparten af blandingerne virkede additivt, og der blev generelt fundet en god overensstemmelse imellem terrestriske og akvatiske planter samt Microtox testen og dafnier.

Kudsk, Per; Andersen, Helle Raun

2006-01-01

378

Bulk pesticide storage - state perspective  

Energy Technology Data Exchange (ETDEWEB)

State bulk pesticide storage regulations continue to evolve differentially due, in large part, to the absence of federal regulations. This is about to change because of the pending promulgation of 40 CFR Part 165, as amended in 1988 by the Environmental Protection Agency (EPA) rules regarding storage, handling and disposal. Until final adoption of the rules by EPA, states continue to address bulk pesticide storage and handling according to individual state statute, rules and guidelines.

Buzicky, G.

1994-12-31

379

The precautionary principle and pesticides  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In 1998, Greenpeace, Natuur en Milieu(Nature and Environment), Milieudefensie(Environmental Defense), and the National ConsumersUnion presented a report about the possible risks andhazards associated with pesticide residues on fruitsand vegetables. Although these organizationsexplicitly denied having unassailable evidence on theharmful effects of pesticides, they claimed that bynow there are sufficient indications that pesticidesmay indeed lead to such health hazards. They used anappeal to th...

Gremmen, H. G. J.; Belt, H.

2000-01-01

380

Trabalho rural e fatores de risco associados ao regime de uso de agrotóxicos em Minas Gerais, Brasil / Rural work and risk factors associated with pesticide use in Minas Gerais, Brazil  

Scientific Electronic Library Online (English)

Full Text Available SciELO Public Health | Language: Portuguese Abstract in portuguese O objetivo deste artigo foi caracterizar o processo do trabalho rural em nove municípios de Minas Gerais, considerando indicadores sócio-demográficos, a estrutura agrária dos estabelecimentos rurais, práticas de trabalho relacionadas ao uso de agrotóxicos e, a intoxicação associada a seu uso. Os dad [...] os foram obtidos de uma pesquisa realizada pela Fundação Jorge Duprat Figueiredo, de Segurança e Medicina do Trabalho, que aplicou um questionário a 1.064 trabalhadores rurais, entre os anos de 1991 a 2000. Por meio de uma regressão logística, foram obtidos os fatores de risco associados à intoxicação por agrotóxicos dos grupos organofosforados e carbamatos. Cerca de 50% dos entrevistados se encontravam ao menos moderadamente intoxicados. Os fatores de risco encontrados foram: ter o último contato a menos de duas semanas com agrotóxicos; não usar proteção; ser orientado pelo vendedor; citar organofosforado ou carbamato como agrotóxico principal e trabalhar nos municípios de Teófoli Otoni, Guidoval ou Piraúba. Os resultados apontam para o alto grau de risco de agravos à saúde a que estão sujeitos trabalhadores rurais em contato com agrotóxicos. Abstract in english This paper aimed to characterize the rural work process in nine counties in Minas Gerais State, considering socio-demographic indicators, the land tenure structure of farm operations, and work practices related to pesticide use and poisoning Data were obtained through the Jorge Duprat Figueiredo Fou [...] ndation for Workers' Safety and Occupational Medicine, which applied a questionnaire to 1,064 rural workers from 1991 to 2000. Through a logistic regression, risk factors associated with pesticide poisoning were obtained for the carbamate and organophosphate groups. Some 50% of interviewees displayed at least moderate pesticide toxicity. Risk factors for pesticide poisoning were: last contact with pesticides less than two weeks before the blood cholinesterase test; no use of personal protective equipment by workers applying pesticides; having received instructions from the pesticide salesperson; report of carbamates/organophosphates as the main pesticides used; and working in the counties of Teófoli Otoni, Guidoval, or Piraúba. The results emphasize the high level of health risk associated with pesticide use among these rural workers.

Wagner, Soares; Renan Moritz V. R., Almeida; Sueli, Moro.

 
 
 
 
381

Trabalho rural e fatores de risco associados ao regime de uso de agrotóxicos em Minas Gerais, Brasil Rural work and risk factors associated with pesticide use in Minas Gerais, Brazil  

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Full Text Available O objetivo deste artigo foi caracterizar o processo do trabalho rural em nove municípios de Minas Gerais, considerando indicadores sócio-demográficos, a estrutura agrária dos estabelecimentos rurais, práticas de trabalho relacionadas ao uso de agrotóxicos e, a intoxicação associada a seu uso. Os dados foram obtidos de uma pesquisa realizada pela Fundação Jorge Duprat Figueiredo, de Segurança e Medicina do Trabalho, que aplicou um questionário a 1.064 trabalhadores rurais, entre os anos de 1991 a 2000. Por meio de uma regressão logística, foram obtidos os fatores de risco associados à intoxicação por agrotóxicos dos grupos organofosforados e carbamatos. Cerca de 50% dos entrevistados se encontravam ao menos moderadamente intoxicados. Os fatores de risco encontrados foram: ter o último contato a menos de duas semanas com agrotóxicos; não usar proteção; ser orientado pelo vendedor; citar organofosforado ou carbamato como agrotóxico principal e trabalhar nos municípios de Teófoli Otoni, Guidoval ou Piraúba. Os resultados apontam para o alto grau de risco de agravos à saúde a que estão sujeitos trabalhadores rurais em contato com agrotóxicos.This paper aimed to characterize the rural work process in nine counties in Minas Gerais State, considering socio-demographic indicators, the land tenure structure of farm operations, and work practices related to pesticide use and poisoning Data were obtained through the Jorge Duprat Figueiredo Foundation for Workers' Safety and Occupational Medicine, which applied a questionnaire to 1,064 rural workers from 1991 to 2000. Through a logistic regression, risk factors associated with pesticide poisoning were obtained for the carbamate and organophosphate groups. Some 50% of interviewees displayed at least moderate pesticide toxicity. Risk factors for pesticide poisoning were: last contact with pesticides less than two weeks before the blood cholinesterase test; no use of personal protective equipment by workers applying pesticides; having received instructions from the pesticide salesperson; report of carbamates/organophosphates as the main pesticides used; and working in the counties of Teófoli Otoni, Guidoval, or Piraúba. The results emphasize the high level of health risk associated with pesticide use among these rural workers.

Wagner Soares

2003-08-01

382

Trabalho rural e fatores de risco associados ao regime de uso de agrotóxicos em Minas Gerais, Brasil / Rural work and risk factors associated with pesticide use in Minas Gerais, Brazil  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese O objetivo deste artigo foi caracterizar o processo do trabalho rural em nove municípios de Minas Gerais, considerando indicadores sócio-demográficos, a estrutura agrária dos estabelecimentos rurais, práticas de trabalho relacionadas ao uso de agrotóxicos e, a intoxicação associada a seu uso. Os dad [...] os foram obtidos de uma pesquisa realizada pela Fundação Jorge Duprat Figueiredo, de Segurança e Medicina do Trabalho, que aplicou um questionário a 1.064 trabalhadores rurais, entre os anos de 1991 a 2000. Por meio de uma regressão logística, foram obtidos os fatores de risco associados à intoxicação por agrotóxicos dos grupos organofosforados e carbamatos. Cerca de 50% dos entrevistados se encontravam ao menos moderadamente intoxicados. Os fatores de risco encontrados foram: ter o último contato a menos de duas semanas com agrotóxicos; não usar proteção; ser orientado pelo vendedor; citar organofosforado ou carbamato como agrotóxico principal e trabalhar nos municípios de Teófoli Otoni, Guidoval ou Piraúba. Os resultados apontam para o alto grau de risco de agravos à saúde a que estão sujeitos trabalhadores rurais em contato com agrotóxicos. Abstract in english This paper aimed to characterize the rural work process in nine counties in Minas Gerais State, considering socio-demographic indicators, the land tenure structure of farm operations, and work practices related to pesticide use and poisoning Data were obtained through the Jorge Duprat Figueiredo Fou [...] ndation for Workers' Safety and Occupational Medicine, which applied a questionnaire to 1,064 rural workers from 1991 to 2000. Through a logistic regression, risk factors associated with pesticide poisoning were obtained for the carbamate and organophosphate groups. Some 50% of interviewees displayed at least moderate pesticide toxicity. Risk factors for pesticide poisoning were: last contact with pesticides less than two weeks before the blood cholinesterase test; no use of personal protective equipment by workers applying pesticides; having received instructions from the pesticide salesperson; report of carbamates/organophosphates as the main pesticides used; and working in the counties of Teófoli Otoni, Guidoval, or Piraúba. The results emphasize the high level of health risk associated with pesticide use among these rural workers.

Wagner, Soares; Renan Moritz V. R., Almeida; Sueli, Moro.

383

Pesticide volatilization from soil and plant surfaces: Measurements at different scales versus model predictions  

Energy Technology Data Exchange (ETDEWEB)

Simulation of pesticide volatilization from plant and soil surfaces as an integral component of pesticide fate models is of utmost importance, especially as part of the PEC (predicted environmental concentrations) models used in the registration procedures for pesticides. Experimentally determined volatilization rates at different scales were compared to model predictions to improve recent approaches included in European registration models. To assess the influence of crucial factors affecting volatilization under well-defined conditions, a laboratory chamber was set-up and validated. Aerodynamic conditions were adjusted to fulfill the requirements of the German guideline on assessing pesticide volatilization for registration purposes. At the semi-field scale, volatilization rates were determined in a wind-tunnel study after soil surface application of pesticides to gleyic cambisol. The following descending order of cumulative volatilization was observed: chlorpyrifos > parathion-methyl > terbuthylazine > fenpropimorph. Parameterization of the models PEARL (pesticide emission assessment at regional and local scales) and PELMO (pesticide leaching model) was performed to mirror the experimental boundary conditions. (orig.)

Wolters, A.

2003-07-01

384

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

385

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 < 20%. The limits of quantification (LOQ) for all 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

386

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 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

2003-05-01

387

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

Directory of Open Access Journals (Sweden)

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

Liqiang Wu

2011-04-01

388

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.

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

2014-01-01

389

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

390

Non-Hodgkin Lymphoma and Occupational Exposure to Agricultural Pesticide Chemical Groups and Active Ingredients: A Systematic Review and Meta-Analysis  

Directory of Open Access Journals (Sweden)

Full Text Available 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.

Leah Schinasi

2014-04-01

391