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1

Carbamate pesticide induced toxic epidermal necrolysis  

Directory of Open Access Journals (Sweden)

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

Rajendran N; Chitfambalam P; Jayaraman A

2001-01-01

2

PESTICIDAL COMPOUND MIXTURES COMPRISING ETHIPROLE AND SPECIFIC CARBAMATES  

UK PubMed Central (United Kingdom)

The present invention relates to novel pesticidal combinations comprising ethiprole as component A and carbamates as component B comprised of alanycarb, aldicarb, aldoxycarb, allyxycarb, aminocarb, bendiocarb, benfuracarb, buprofezin, bufencarb, butacarb, butocarboxim, butoxycarboxim, carbaryl, carbofuran, carbo- sulfan, chloethocarb, dimetilan, ethiofencarb, fenobucarb, fenothiocarb, formetanate, furathiocarb, isoprocarb, metam-sodium, methiocarb, methomyl, metolcarb, oxamyl, phosphocarb, pirimicarb, promecarb, propoxur, thiodicarb, thiofanox, triazamate, trimethacarb, XMC, xylylcarb that show surprisingly good pesticidal activities.

HUNGERNBERG HEIKE; VELDEN TORSTEN; THIELERT WOLFGANG; TESSON ERIC

3

Pesticidal compound mixtures comprising ethiprole and specific carbamates  

UK PubMed Central (United Kingdom)

The present invention relates to novel pesticidal combinations comprising ethiprole as component A and carbamates as component B comprised of alanycarb, aldicarb, aldoxycarb, allyxycarb, aminocarb, bendiocarb, benfuracarb, bufencarb, butacarb, butocarboxim, butoxycarboxim, carbaryl, carbofuran, carbosulfan, chloethocarb, dimetilan, ethiofencarb, fenobucarb, fenothiocarb, formetanate, furathiocarb, isoprocarb, metam-sodium, methiocarb, methomyl, metolcarb, oxamyl, phosphocarb, pirimicarb, promecarb, propoxur, thiodicarb, thiofanox, triazamate, trimethacarb, XMC, xylylcarb that show surprisingly good pesticidal and activities.

4

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

5

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

6

Enzyme-based electrochemical biosensors for determination of organophosphorus and carbamate pesticides  

Energy Technology Data Exchange (ETDEWEB)

A mini review of enzyme-based electrochemical biosensors for inhibition analysis of organophosphorus and carbamate pesticides is presented. Discussion includes the most recent literature to present advances in detection limits, selectivity and real sample analysis. Recent reviews on the monitoring of pesticides and their residues suggest that the classical analytical techniques of gas and liquid chromatography are the most widely used methods of detection. These techniques, although very accurate in their determinations, can be quite time consuming and expensive and usually require extensive sample clean up and pro-concentration. For these and many other reasons, the classical techniques are very difficult to adapt for field use. Numerous researchers, in the past decade, have developed and made improvements on biosensors for use in pesticide analysis. This mini review will focus on recent advances made in enzyme-based electrochemical biosensors for the determinations of organophosphorus and carbamate pesticides.

Everett, W.R.; Rechnitz, G.A. [Univ. of Hawaii, Honolulu, HI (United States)

1999-01-01

7

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...

8

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

2010-05-25

9

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

UK PubMed Central (United Kingdom)

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.

Omamogho JO; Stack EM; Santalad A; Srijaranai S; Glennon JD; Yamen H; Albert K

2010-07-01

10

Transformation and ecotoxicity of carbamic pesticides in water.  

UK PubMed Central (United Kingdom)

BACKGROUND: N-methylcarbamate insecticides are widely used chemicals for crop protection. This study examines the hydrolytic and photolytic cleavage of benfuracarb, carbosulfan and carbofuran under natural conditions. Their toxicity and that of the corresponding main degradation products toward aquatic organisms were evaluated. METHODS: Suspensions of benfuracarb, carbosulfan and carbofuran in water were exposed to sunlight, with one set of dark controls, for 6 days, and analyzed by 1H-NMR and HPLC. Acute toxicity tests were performed on Brachionus calyciflorus, Daphnia magna, and Thamnocefalus platyurus. Chronic tests were performed on Pseudokirchneriella subcapitata, and Ceriodaphnia dubia. RESULTS AND DISCUSSION: Under sunlight irradiation, benfuracarb and carbosulfan gave off carbofuran and carbofuran-phenol, while only carbofuran was detected in the dark experiments. The latter was degraded to phenol by exposure to sunlight. Effects of pH, humic acid and KNO3 were evaluated by kinetics on dilute solutions in the dark and by UV irradiation, which evidenced the lability of the pesticide at pH 9. All three pesticides and phenol exhibited acute and higher chronic toxicity towards the aquatic organisms tested. CONCLUSION: Investigation on the hydrolysis and photolysis of benfuracarb and carbosulfan under natural conditions provides evidence concerning the selective decay to carbofuran and/or phenol. Carbofuran is found to be more persistent and toxic. RECOMMENDATIONS AND OUTLOOK: The decay of benfuracarb and carbosulfan to carbofuran and the relative stability of this latter pesticide account for many papers that report the detection of carbofuran in water, fruits and vegetables.

Iesce MR; della Greca M; Cermolal F; Rubino M; Isidori M; Pascarella L

2006-03-01

11

Isolation of soil bacteria able to hydrolyze both organophosphate and carbamate pesticides.  

UK PubMed Central (United Kingdom)

Two bacteria identified as Pseudomonas putida and Acinetobacter rhizosphaerae able to rapidly degrade the organophosphate (OP) fenamiphos (FEN) were isolated. Denaturating gradient gel electrophoresis analysis revealed that the two isolates were dominant members of the enrichment culture. Clone libraries further showed that bacteria belonging to ?-, ?-, ?-proteobacteria and Bacteroidetes were also present in the final enrichment but were not isolated. Both strains hydrolyzed FEN to fenamiphos phenol which was further transformed, only by P. putida. The two strains were using FEN as C and N source. Cross-feeding studies with other pesticides showed that P. putida degraded OPs with a P-O-C linkage and unexpectedly degraded the carbamates oxamyl and carbofuran being the first wild-type bacterial strain able to degrade both OPs and carbamates. The same isolate exhibited high bioremediation potential against spillage-level concentrations of aged residues of FEN and its oxidized derivatives.

Chanika E; Georgiadou D; Soueref E; Karas P; Karanasios E; Tsiropoulos NG; Tzortzakakis EA; Karpouzas DG

2011-02-01

12

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

Directory of Open Access Journals (Sweden)

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

SOMERSET V.; BAKER P.; IWUOHA E.

2013-01-01

13

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 ...

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

14

Flow-injection spectrophotometric determination of phenolic drugs and carbamate pesticides by coupling with diazotized 2,4,6-trimethylaniline.  

UK PubMed Central (United Kingdom)

A flow-injection (FI) spectrophotometric system is proposed for the determination of phenols and carbamates. In the FI manifolds, the solutions of phenols or carbamates (the latter after hydrolysis with NaOH) were injected into a diazonium ion carrier stream at pH 9.5 (buffered with tetrahydroborate), which was formed by mixing 2,4,6-trimethylaniline (TMA) with nitrate in a sodium dodecyl sulfate aqueous micellar medium. Absorbance was measured at 550 nm. The system combines the advantages derived from the use of TMA for the coupling of phenols in basic micellar media, because of the inhibition of the self-coupling reaction of the reagent, with the precision and speed of the FI procedures. Other diazotized reagents produced excessive blank signals. The procedures were successfully applied to the determination of phenolic drugs (epinephrine, acetaminophen, and gualacol) in pharmaceuticals and carbamates (bendiocarb, benfuracarb, carbaryl, carbofuran, methiocarb, promecarb, and propoxur) in pesticide products and water samples.

Alvarez-Rodriguez L; Esteve-Romero J; Escrig-Tena I; Garcia Alvarez-Coque MC

1999-07-01

15

Flow-injection spectrophotometric determination of phenolic drugs and carbamate pesticides by coupling with diazotized 2,4,6-trimethylaniline.  

Science.gov (United States)

A flow-injection (FI) spectrophotometric system is proposed for the determination of phenols and carbamates. In the FI manifolds, the solutions of phenols or carbamates (the latter after hydrolysis with NaOH) were injected into a diazonium ion carrier stream at pH 9.5 (buffered with tetrahydroborate), which was formed by mixing 2,4,6-trimethylaniline (TMA) with nitrate in a sodium dodecyl sulfate aqueous micellar medium. Absorbance was measured at 550 nm. The system combines the advantages derived from the use of TMA for the coupling of phenols in basic micellar media, because of the inhibition of the self-coupling reaction of the reagent, with the precision and speed of the FI procedures. Other diazotized reagents produced excessive blank signals. The procedures were successfully applied to the determination of phenolic drugs (epinephrine, acetaminophen, and gualacol) in pharmaceuticals and carbamates (bendiocarb, benfuracarb, carbaryl, carbofuran, methiocarb, promecarb, and propoxur) in pesticide products and water samples. PMID:10444831

Alvarez-Rodriguez, L; Esteve-Romero, J; Escrig-Tena, I; Garcia Alvarez-Coque, M C

16

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

17

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

UK PubMed Central (United Kingdom)

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

Song W; Zhang Y; Li G; Chen H; Wang H; Zhao Q; He D; Zhao C; Ding L

2014-01-01

18

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

Science.gov (United States)

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

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

2013-07-30

19

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

20

Occupational Exposure to Organophosphate and Carbamate Pesticides Affects Sperm Chromatin Integrity and Reproductive Hormone Levels among Venezuelan Farm Workers.  

UK PubMed Central (United Kingdom)

Objectives: Several reports suggest that chronic pesticide exposure may affect semen quality and male fertility in humans. The objective of this study was to evaluate the association between occupational exposure to organophosphate (OP) and carbamate (CB) pesticides and semen quality, as well as levels of reproductive and thyroid hormones of Venezuelan farm workers. Methods: Thirty-five healthy men (unexposed group) and 64 male agricultural workers (exposed group) were recruited for clinical evaluation of fertility status. Fresh semen samples were evaluated for sperm quality and analyzed for DNA fragmentation index (DFI) by flow cytometry. Pesticide exposure was assessed by measuring erythrocyte acetylcholinesterase (AChE) and plasma butyrylcholinesterase (BuChE) with a Test-mate ChE field kit. Serum levels of total testosterone (Tt), follicle-stimulating hormone (FSH), luteinizing hormone (LH), prolactin (PRL), thyroid stimulating hormone (TSH) and free thyroxine (FT4) were analyzed using enzyme immunoassay kits. Results: Evidence of pesticide exposure was found in 87.5% of farmers based on AChE and BuChE inhibition. Significant increments were observed in sperm DFI with significant decreases in some semen parameters. DFI was negatively correlated with BuChE, sperm concentration, morphology and vitality in these workers. The levels of Tt, PRL, FT4 and TSH appeared to be normal; however, there was a tendency for increased LH and FSH levels in exposed workers. Conclusions: Our results confirm the potential impact of chronic occupational exposure to OP/CB pesticides on male reproductive function, which may cause damage to sperm chromatin, decrease semen quality and produce alterations in reproductive hormones, leading to adverse reproductive health outcomes.

Miranda-Contreras L; Gómez-Pérez R; Rojas G; Cruz I; Berrueta L; Salmen S; Colmenares M; Barreto S; Balza A; Zavala L; Morales Y; Molina Y; Valeri L; Contreras CA; Osuna JA

2013-02-01

 
 
 
 
21

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

22

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...

23

Surface Display of Recombinant Drosophila melanogaster Acetylcholinesterase for Detection of Organic Phosphorus and Carbamate Pesticides  

Science.gov (United States)

Acetylcholinesterase (AChE) is commonly used for the detection of organophosphate (OP) and carbamate (CB) insecticides. However, the cost of this commercially available enzyme is high, making high-throughput insecticide detection improbable. In this study we constructed a new AChE yeast expression system in Saccharomyces cerevisiae for the expression of a highly reactive recombinant AChE originating from Drosophila melanogaster (DmAChE). Specifically, the coding sequence of DmAChE was fused with the 3?-terminal half of an ?-agglutinin anchor region, along with an antigen tag for the detection of the recombinant protein. The target sequence was cloned into the yeast expression vector pYes-DEST52, and the signal peptide sequence was replaced with a glucoamylase secretion region for induced expression. The resultant engineered vector was transformed into S. cerevisiae. DmAChE was expressed and displayed on the cell surface after galactose induction. Our results showed that the recombinant protein displayed activity comparable to the commercial enzyme. We also detected different types of OP and CB insecticides through enzyme inhibition assays, with the expressed DmAChE showing high sensitivity. These results show the construction of a new yeast expression system for DmAChE, which can subsequently be used for detecting OP and CB insecticides with reduced economic costs.

Wu, Songjie; Zhuan, Fangfang; Xu, Songci; Li, Junyang; Salazar, Joelle K.; Zhang, Wei; Wang, Hui

2013-01-01

24

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

25

Development and validation of analytical methods for ethyl carbamate in various fermented foods  

UK PubMed Central (United Kingdom)

The aim of this work was to develop and validate analytical methods for ethyl carbamate (EC) in various food matrices. Column chromatography was used for the analysis of EC in kimchi, a fermented soybean paste (doenjang), a fermented fish product (jeotgal), yoghurt, bread, and cheese. To remove the fat in the bread and cheese, a Florisil cartridge was selected. The volume of dichloromethane in the chromatography column was optimised to 60mL for the kimchi, cheese, and fermented soybean paste. For the bread, jeotgal, and yoghurt, the best recovery rate was found by using 100mL of dichloromethane. For the accurate analysis of EC in the vinegar, 150mL of dichloromethane and a neutralisation process (pH=8.0) were required. In the standard curve of EC, satisfactory linearity (R ² =0.998) was shown. The limit of quantification (LOQ) was 10ng/mL and the recovery rates ranged from 76.9% to 118.1%. Intra- and inter-assay precision ranged from 3.5% to 34.2% and 3.8% to 41.9%, respectively.

Lim HS; Lee KG

2011-06-01

26

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

27

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

UK PubMed Central (United Kingdom)

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.

Tian Q; Lv C; Wang P; Ren L; Qiu J; Li L; Zhou Z

2007-02-01

28

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

International Nuclear Information System (INIS)

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

2010-06-25

29

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

UK PubMed Central (United Kingdom)

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.

Assis CR; Castro PF; Amaral IP; Carvalho EV; Carvalho LB Jr; Bezerra RS

2010-10-01

30

Development of a computer-based survey instrument for organophosphate and N-methyl-carbamate exposure assessment among agricultural pesticide handlers.  

UK PubMed Central (United Kingdom)

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 male agricultural pesticide handlers for an ongoing cholinesterase biomonitoring study in Washington State. OBJECTIVES: To assess the feasibility of collecting data using the A-CASI instrument and evaluate reliability for a subset of survey items. METHODS: The survey consisted of 64 items administered in Spanish or English on a touch-screen tablet computer. Participants listened to digitally recorded questions on headphones and selected responses on the screen, most of which were displayed as images or icons to facilitate participation of low literacy respondents. From 2006-2008, a total of 195 participants completed the survey during the OP/CB application seasons on at least one occasion. Percent agreement and kappa coefficients were calculated to evaluate test-retest reliability for selected characteristics among 45 participants who completed the survey on two separate occasions within the same year. RESULTS: Almost all participants self-identified as Hispanic or Latino (98%), and 97% completed the survey in Spanish. Most participants completed the survey in a half-hour or less, with minimal assistance from on-site research staff. Analyses of test-retest reliability showed substantial agreement for most demographic, work history, and health characteristics and at least moderate agreement for most variables related to personal protective equipment use during pesticide applications. CONCLUSIONS: This A-CASI survey instrument is a novel method that has been used successfully to collect information about OP/CB exposures and other personal characteristics among Spanish-speaking agricultural pesticide handlers.

Hofmann JN; Checkoway H; Borges O; Servin F; Fenske RA; Keifer MC

2010-08-01

31

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

Directory of Open Access Journals (Sweden)

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

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

2007-01-01

32

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

Directory of Open Access Journals (Sweden)

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

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

2007-01-01

33

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

Scientific Electronic Library Online (English)

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

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

2007-09-01

34

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

Science.gov (United States)

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

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

2003-11-01

35

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

UK PubMed Central (United Kingdom)

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

Bradman A; Barr DB; Claus Henn BG; Drumheller T; Curry C; Eskenazi B

2003-11-01

36

[Effect of carbamate pesticides on the induction of hepatic enzymes of the rat and on the microsomal phospholipid changes  

UK PubMed Central (United Kingdom)

The influence of two carbamine pesticides i.e., manebe and carbaryl upon the hepatic microsomal enzymes induction in the rat was studied. Both substances, when administered by themselves, affect only slightly liver weight, P 450 cytochrome rates and bilirubin glucuronosyltransferase, in the microsome fraction of the hepatic homogenate. It seems, however, that carbaryl is involved in producing a slight induction, whereas manebe acts inversely. Yet, manebe changes largely the induction effects of phenobarbital when associated with the latter. In the animal treated simultaneously with manebe and phenobarbital, the increase in the rate of hepatic microsomal P 450 cytochrome as well as the variations in the distribution of fatty acids in phospholipids, are significantly lower than in the animal solely treated with phenobarbital.

Mountié J; Rivera F; Goudonnet H; Escousse A; Truchot RC

1983-09-01

37

Carbamates toxicity in farmers and its assesment through biochemical parameters  

International Nuclear Information System (INIS)

Prevalent environmental toxicity of various chemical group of pesticides and their effects leading towards increasing morbidity and mortality in the farmers is of great concerned. In this situation the biochemical biomarkers are regarded as meaningful tools for monitoring toxic end points. This work was aimed to assess the toxic impacts of carbamates through some biochemical parameters and useful validity of these biomarkers was also observed. Present results reveal inhibition of cholinesterase activity by 46% whereas bilirubin, urea and creatinine levels in serum were increased and sugar values was decreased at highly significant level (p

2005-01-01

38

Pesticidal compositions  

UK PubMed Central (United Kingdom)

Pesticidal compositions containing as active ingredients 3,5-dichloro-1-(3,3-dichloro-2-propenyloxy)-4-[3-(5-trifluoromethylpyridin-2-yloxy)pro poxy]benzene of the formula:and at least one carbamate compound selected from thiodicarb, methomyl and alanycarb have excellent pesticidal activity by their synergistic cooperative action.

SAITO SHIGERU

39

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

UK PubMed Central (United Kingdom)

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

Huang Z; Pan XD; Wu PG; Chen Q; Han JL; Shen XH

2013-12-01

40

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

Science.gov (United States)

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

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

2013-07-04

 
 
 
 
41

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...

42

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 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 métodos. 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 traba (more) jadores 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 (more) 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

2005-06-01

43

Safety evaluation of chemicals in food: toxicological data profiles for pesticides: 1. Carbamate and organophosphorus insecticides used in agriculture and public health  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The sources of the scientific information used over the past several years by the Joint FAO/WHO Meetings on Pesticide Residues in carrying out toxicological evaluations are classified systematically according to compound and subject for the first time in this paper. It is hoped that those engaged in...

Vettorazzi, G.; Miles-Vettorazzi, P.

44

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

45

Development of a simple combining apparatus to perform a magnetic stirring-assisted dispersive liquid-liquid microextraction and its application for the analysis of carbamate and organophosphorus pesticides in tea drinks.  

UK PubMed Central (United Kingdom)

This study introduced a simple combining apparatus for performing a magnetic stirring-assisted dispersive liquid-liquid microextraction (MSA-DLLME) for the detection of trace carbamate and organophosphorus pesticides in tea drinks coupled with high performance liquid chromatography. The simple combining apparatus was made up of a sample vial and a cut plastic dropper. The bulb end of the cut plastic dropper was inserted into the neck of the sample vial and the open tip end of the plastic dropper was then cut to an appropriate length. The combining apparatus made was then used to perform the MSA-DLLME. In this experiment, 1-octanol was injected into the tea drink sample solution and the extraction process accelerated by magnetic agitation. The sample solution turned clear and separated into two layers after leaving it alone for several minutes. The cut plastic dropper was gently put down into the sample vial, and then the liquid level of the sample solution elevated up to the tip of the plastic dropper for the collection of low-density extractant. Finally, the collected extractant was drawn out by a microsyringe and injected into the high performance liquid chromatography-diode-array detector for analysis. A series of extraction parameters were investigated and optimized. Under the most favorable conditions, high enrichment factors were obtained for carbofuran, carbaryl and isocarbophos (between 130 and 185). The limits of detection (S/N=3) were in the range of 0.13-0.61 ?g L(-1), and the relative standard deviation varied below 7.8% (n=5). Additionally, good recoveries were obtained between 79.4% and 114.4% in the three tea drinks. The simple combining apparatus utilized in this MSA-DLLME method was shown to be economical, fast, and convenient for the collection of low density extractant.

Wang X; Cheng J; Zhou H; Wang X; Cheng M

2013-07-01

46

Pesticides  

Energy Technology Data Exchange (ETDEWEB)

This review covers the literature on pesticide analysis published or abstracted in the period between December 15, 1984, and December 15, 1986. The major sources of information were the primary abstracting journals Chemical Abstracts and Analytical Abstracts. Journals that were searched directly include the Journal of the Association of Official Analytical Chemists, Journal of Agricultural and Food Chemistry, Bulletin of Environmental Contamination and Toxicology, Analytical Chemistry, and the Journal of Chromatography (including its bibliography issues). The review is devoted mainly to methods for the determination of residues of pesticides and related compounds in a wide variety of samples and the analysis of pesticide standards. Analyses of pesticide formulations are not covered. The attempt was made to choose the most important publications describing methodology, instrumentation, and applications that would be readily available to readers to this Journal. Abstract citations are given for references from the more obscure journals and those not published in English.

Sherma, J.

1987-06-15

47

Development and validation of a grouping method for pesticides analysed in foodstuffs.  

UK PubMed Central (United Kingdom)

The cost effective monitoring of hundreds of pesticide residues in foodstuffs of vegetable origin involves the definition of groups of analytes associated with homogeneous performance parameters of the used analytical method. The performance of the analytical method only needs to be tested on a daily base for some of these group's compounds. This work proposes a strategy for defining groups of compounds with homogeneous physical-chemical properties based on the evaluation of the similarity of the multivariate pattern of five of these properties namely: molar mass, melting point, vapour pressure at 20 °C, n-octanol-water partition coefficient and solubility in water at 20 or 25 °C. Three independent and competing multivariate analysis tools, namely Principal Component Analysis, Hierarchical Clustering and K-Mean Clustering were used. This strategy was successfully used to group 100 pesticides into nine clusters, with 1-40 pesticides, represented by a compound with within group average properties. The developed grouping method was validated using physical-chemical data from other references or compounds and produced groups consistent with the performance of the studied determination of pesticide residues in dried red bean. The mean analyte recoveries of groups with larger dimension are statistically different for a confidence level of 95%. The within group coefficients of variance of mean analyte recoveries of larger groups ranged from 6.7% to 8.5%. This grouping method can reduce the number of recovery tests performed for the validation of the analytical method or test quality control.

Bettencourt da Silva RJ; Dias PM; Camões MF

2012-10-01

48

Development and validation of a grouping method for pesticides analysed in foodstuffs  

UK PubMed Central (United Kingdom)

The cost effective monitoring of hundreds of pesticide residues in foodstuffs of vegetable origin involves the definition of groups of analytes associated with homogeneous performance parameters of the used analytical method. The performance of the analytical method only needs to be tested on a daily base for some of these group’s compounds. This work proposes a strategy for defining groups of compounds with homogeneous physical–chemical properties based on the evaluation of the similarity of the multivariate pattern of five of these properties namely: molar mass, melting point, vapour pressure at 20°C, n-octanol–water partition coefficient and solubility in water at 20 or 25°C. Three independent and competing multivariate analysis tools, namely Principal Component Analysis, Hierarchical Clustering and K-Mean Clustering were used. This strategy was successfully used to group 100 pesticides into nine clusters, with 1–40 pesticides, represented by a compound with within group average properties. The developed grouping method was validated using physical–chemical data from other references or compounds and produced groups consistent with the performance of the studied determination of pesticide residues in dried red bean. The mean analyte recoveries of groups with larger dimension are statistically different for a confidence level of 95%. The within group coefficients of variance of mean analyte recoveries of larger groups ranged from 6.7% to 8.5%. This grouping method can reduce the number of recovery tests performed for the validation of the analytical method or test quality control.

Bettencourt da Silva RicardoJN; Dias PedroMVBF; Camões MariaFilomenaGFC

2012-10-01

49

Development and validation of a grouping method for pesticides analysed in foodstuffs.  

Science.gov (United States)

The cost effective monitoring of hundreds of pesticide residues in foodstuffs of vegetable origin involves the definition of groups of analytes associated with homogeneous performance parameters of the used analytical method. The performance of the analytical method only needs to be tested on a daily base for some of these group's compounds. This work proposes a strategy for defining groups of compounds with homogeneous physical-chemical properties based on the evaluation of the similarity of the multivariate pattern of five of these properties namely: molar mass, melting point, vapour pressure at 20 °C, n-octanol-water partition coefficient and solubility in water at 20 or 25 °C. Three independent and competing multivariate analysis tools, namely Principal Component Analysis, Hierarchical Clustering and K-Mean Clustering were used. This strategy was successfully used to group 100 pesticides into nine clusters, with 1-40 pesticides, represented by a compound with within group average properties. The developed grouping method was validated using physical-chemical data from other references or compounds and produced groups consistent with the performance of the studied determination of pesticide residues in dried red bean. The mean analyte recoveries of groups with larger dimension are statistically different for a confidence level of 95%. The within group coefficients of variance of mean analyte recoveries of larger groups ranged from 6.7% to 8.5%. This grouping method can reduce the number of recovery tests performed for the validation of the analytical method or test quality control. PMID:23442688

Bettencourt da Silva, Ricardo J N; Dias, Pedro M V B F; Camões, Maria Filomena G F C

2012-03-29

50

(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...

51

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.

2009-01-01

52

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

UK PubMed Central (United Kingdom)

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

Alcántara-Concepción V; Cram S; Gibson R; Ponce de León C; Mazari-Hiriart M

2013-07-01

53

Carbamate and organophosphate poisoning in young children.  

UK PubMed Central (United Kingdom)

OBJECTIVE: Retrospective evaluation of the clinical course of carbamate and organophosphate poisoning in young children. DESIGN: The records of 36 children intoxicated with carbamate and 16 children intoxicated with organophosphate (age range: 2 to 8 years, median: 2.8 years) were examined retrospectively. The carbamate agents were identified as methomyl or aldicarb, and the organophosphate as parathion, fenthion, malathion, and diazinon. The causes of poisoning were accidental ingestion in 46 children and inhalation in six children. CLINICAL SETTING: Pediatric Intensive Care Unit of a teaching hospital. INTERVENTIONS: Gastric lavage was performed, and activated charcoal was administered to all children who had ingested poisonous pesticides. Atropine sulphate was administered intravenously in repeated doses to all children with bradycardia, diarrhea, salivation, and miosis. Obidoxime chloride was administered to patients with organophosphate poisoning and to those in whom the ingested material was unidentified on admission. RESULTS: Predominant symptoms were related to central nervous system depression and severe hypotonia. Other clinical signs such as miosis, diarrhea, salivation, bradycardia, and fasciculation were less frequent, while tearing and diaphoresis were not observed. Pulmonary edema developed in six patients with organophosphte poisoning. Three children required mechanical ventilation for several hours. One child (organophosphate poisoning) died shortly after arrival at the emergency department. All other children recovered completely. CONCLUSION: Based on a relatively large group of young pediatric patients with carbamate and organophosphate poisoning, it is concluded that the clinical presentation differed from those described in adults. Absence of classic muscarinic effects does not exclude the possibility of cholinesterase inhibitor agents poisoning in young children with central nervous system depression.

Lifshitz M; Shahak E; Sofer S

1999-04-01

54

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

2010-12-10

55

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

UK PubMed Central (United Kingdom)

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.

Park JH; Mamun MI; Abd El-Aty AM; Na TW; Choi JH; Ghafar MW; Kim KS; Kim SD; Shim JH

2011-09-01

56

[Algorithm validation for pesticide exposure risk evaluation by environmental monitoring data  

UK PubMed Central (United Kingdom)

The risk evaluation related to the occupational exposure to hazardous substances can be performed either by analytical data coming from environmental and/or biological monitoring or by using models and mathematical algorithms. Models are often considered economically more advantageous, nevertheless, in order to assure their reliability, they need to be validated by objective monitoring data. A predictive model for the evaluation of risks due to the exposure to pesticides in agriculture was elaborated, and, for model validations, 20 tomato farms were examined. For each farm, information necessary to the risk evaluation by using the elaborated algorithm were collected and, simultaneously, an environmental monitoring for the evaluation of inhaling and cutaneous exposure was carried out. The potential risk was estimated by comparing analytical data from environmental monitoring with respect to ADI (Admissible Daily Intake) values, for each investigated pesticide. Then, the accordance between the potential risk and the risk given by the elaborated model was evaluated and an agreement of 85.6% was found, showing a substantial reliability of the proposed model.

Miraglia N; Simonelli A; Basilicata P; Genovese G; Acampora A; Sannolo N

2007-07-01

57

Pesticides in groundwater: the aldicarb story in Suffolk County, NY.  

UK PubMed Central (United Kingdom)

Aldicarb, a carbamate pesticide, was detected for the first time in groundwater in Suffolk County, New York, in August 1979. Although all laboratory and field studies indicated that the pesticide could not reach groundwater, a combination of circumstances allowed its residues not only to reach groundwater but also to be ingested by humans. Inquiries in hospitals and poison control centers did not reveal any cases of carbamate poisoning. The extensive monitoring program, conducted by the County in cooperation with the federal and state agencies and the Union Carbide Corporation, showed that 1,121 (13.5 per cent) of the 8,404 wells examined exceeded the state recommended guidelines of 7 ppb. Of the contaminated wells 52 per cent contained adicarb between 8 and 30 ppb, 32 per cent between 31 and 75 ppb, and 16 per cent more that 75 ppb. Residents whose wells exceeded the guideline were advised not to use the water for drinking or cooking purposes and to obtain an alternate source of potable water. The Union Carbide Corporation provided those residents with activated carbon filtration units. The incident raises several serious issues, such as the testing of pesticides under field conditions prior to registration and during their use, the validity of the recommended actionable levels, and the paucity of long-term epidemiologic studies of the health effects resulting from consumption of pesticides in trace concentrations.

Zaki MH; Moran D; Harris D

1982-12-01

58

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

Scientific Electronic Library Online (English)

Full Text Available 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 em tomate, empregando Cromatografia Gasosa com Detector de Nitrogênio e Fósforo (GC-NPD). A possibilidade de ocorrência de efeito matriz foi estudada. As curvas anal (more) íticas, 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 validated 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 m (more) atrix were linear from 0.006 to 0.80 mg L-1. The precision studies supplied results with RSD

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

2004-12-01

59

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

UK PubMed Central (United Kingdom)

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.

Simplício AL; Boas LV

1999-02-01

60

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

 
 
 
 
61

Development and validation of method for the determination of organochlorine pesticides and trihalomethanes in the water by HRGC-ECD  

Directory of Open Access Journals (Sweden)

Full Text Available The development and validation of a simultaneous liquid-liquid extraction method for organochlorine pesticides and trihalomethanes in surface and drinking water by HRGC-ECD is described. The method presents acceptable recovery, with detection ranging from 2.7 to 49.0 ng L-1 for organochlorine pesticides and from 18.0 to 860.0 ng L-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; Nelson Roberto Antoniosi Filho

2010-01-01

62

Pesticides in groundwater: the aldicarb story in Suffolk County, New York  

Energy Technology Data Exchange (ETDEWEB)

Aldicarb, a carbamate pesticide, was detected for the first time in groundwater in Suffolk County, New York, in August 1979. Although all laboratory and field studies indicated that the pesticide could not reach groundwater, a combination of circumstances allowed its residues not only to reach groundwater but also to be ingested by humans. Inquiries in hospitals and poison control centers did not reveal any cases of carbamate poisoning. The extensive monitoring program, conducted by the County in cooperation with the federal and state agencies and the Union Carbide Corporation, showed that 1,121 (13.5 per cent) of the 8,404 wells examined exceeded the state recommended guidelines of 7 ppb. Of the contaminated wells 52 per cent contained adicarb between 8 and 30 ppb, 32 per cent between 31 and 75 ppb, and 16 per cent more that 75 ppb. Residents whose wells exceeded the guideline were advised not to use the water for drinking or cooking purposes and to obtain an alternate source of potable water. The Union Carbide Corporation provided those residents with activated carbon filtration units. The incident raises several serious issues, such as the testing of pesticides under field conditions prior to registration and during their use, the validity of the recommended actionable levels, and the paucity of long-term epidemiologic studies of the health effects resulting from consumption of pesticides in trace concentrations.

Zaki, M.H.; Moran, D.; Harris, D.

1982-12-01

63

Pesticidal composition and its use  

UK PubMed Central (United Kingdom)

A pesticidal composition comprising a carboxamide compound represented by following formula (I), wherein R1 represents a hydrogen atom or a methyl group, and R2 represents a methyl group, a difluoromethyl group or a trifluoromethyl group, and one or more carbamate compounds selected from group (A) consisting of oxamyl, thiodicarb, carbosulfan, methiocarb and carbofuran is provided by the present invention, and this composition has an excellent pesticidal effect.

MATSUZAKI YUICHI

64

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

65

[Poisoning with methanol and carbamates].  

UK PubMed Central (United Kingdom)

We describe the case of a eleven years old boy with a simultaneous intentional poisoning with methanol and carbamates. The symptomatology was biphasic due to the addition of the symptomatology of both intoxications. Therapeutic measures included gastrointestinal decontamination, sodium bicarbonate, atropine, ethanol administration and hemodialysis.

Oom P; Pereira P; Santos E; Carvalho A; Correia M; Rodrigues G; Sequeira JS

2002-01-01

66

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

UK PubMed Central (United Kingdom)

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

Takatori S; Yamamoto H; Fukui N; Yamaguchi S; Kitagawa Y; Kakimoto Y; Osakada M; Okihashi M; Kajimura K; Obana H

2013-01-01

67

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

68

Automated sample preparation for monitoring groundwater pollution by carbamate insecticides and their transformation products.  

Science.gov (United States)

We investigated automated on-line solid-phase extraction (SPE) followed by liquid chromatographic (LC) techniques for monitoring carbamates and their transformation products. Analytical determinations were performed by LC with UV or postcolumn fluorescence detection (U.S. Environmental Protection Agency Method 531.1 for carbamate insecticides) after preconcentration with on-line SPE using C18 Empore extraction disks. On-line SPE/LC/thermospray mass spectrometry with time-scheduled selected-ion monitoring was used as confirmatory method. The method was used to determine pesticide traces in well waters of a typical aquifer in the Almeria area (Andalucia, south of Spain) from March 1993 to February 1994. The major pollutants, found in highest amounts, were carbofuran, methiocarb, and methomyl, at levels of 0.32, 0.3, and 0.8 micrograms/L, respectively. According to results of seasonal variation studies, pollution by carbamate insecticides is sporadic and exceeds the limit of 0.5 micrograms/L for total pesticides allowed by the European Economic Community Drinking Water Directive only twice a year. 3-Hydroxycarbofuran and methiocarb sulfone also were detected, showing the importance of including the main toxic break-down products of carbamate insecticides in future monitoring programs. PMID:8664569

Chiron, S; Valverde, A; Fernandez-Alba, A; Barceló, D

69

Automated sample preparation for monitoring groundwater pollution by carbamate insecticides and their transformation products.  

UK PubMed Central (United Kingdom)

We investigated automated on-line solid-phase extraction (SPE) followed by liquid chromatographic (LC) techniques for monitoring carbamates and their transformation products. Analytical determinations were performed by LC with UV or postcolumn fluorescence detection (U.S. Environmental Protection Agency Method 531.1 for carbamate insecticides) after preconcentration with on-line SPE using C18 Empore extraction disks. On-line SPE/LC/thermospray mass spectrometry with time-scheduled selected-ion monitoring was used as confirmatory method. The method was used to determine pesticide traces in well waters of a typical aquifer in the Almeria area (Andalucia, south of Spain) from March 1993 to February 1994. The major pollutants, found in highest amounts, were carbofuran, methiocarb, and methomyl, at levels of 0.32, 0.3, and 0.8 micrograms/L, respectively. According to results of seasonal variation studies, pollution by carbamate insecticides is sporadic and exceeds the limit of 0.5 micrograms/L for total pesticides allowed by the European Economic Community Drinking Water Directive only twice a year. 3-Hydroxycarbofuran and methiocarb sulfone also were detected, showing the importance of including the main toxic break-down products of carbamate insecticides in future monitoring programs.

Chiron S; Valverde A; Fernandez-Alba A; Barceló D

1995-11-01

70

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

Scientific Electronic Library Online (English)

Full Text Available 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 aldicarb, carbofuran e carbaril em bebidas de sucos de uva e leite achocolatado. Este método envolve a extração com acetonitrila, partição líquido-líquido em b (more) aixa 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, carbofuran and carbaryl in grape juice and chocolate milk beverages. This method involved extraction with acetonitrile, liquid-liquid partition at low temperature and the analysis (more) 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

2012-06-01

71

Process for producing fluorinated carbamates and isocyanates  

UK PubMed Central (United Kingdom)

The invention relates to a process for producing fluorinated carbamates comprising the reaction between an amine or polyamine and a fluorinated carbonate, in the presence of a catalyst which does not contain metals and comprises at least one tertiary amine group. The process can also comprise an additional step in which the carbamates are transformed into the corresponding isocyanates.

POLO ANA PADILLA; QUITERIA VALENTIN RUIZ SANTA; CANOS AVELINO CORMA; GOMEZ HERMENEGILDO GARCIA; MARIN RAQUEL JUAREZ

72

Process for producing fluorinated isocyanates and carbamates  

UK PubMed Central (United Kingdom)

The invention relates to a process for producing fluorinated carbamates comprising the reaction between an amine or polyamine and a fluorinated carbonate, in the presence of a catalyst which does not contain metals and comprises at least one tertiary amine group. The process can also comprise an additional step in which the carbamates are transformed into the corresponding isocyanates.

PADILLA POLO ANA; RUIZ SANTA QUITERIA VALENTIN; CORMA CANOS AVELINO; GARCIA GOMES HERMENEGILDO; JUAREZ MARIN RAQUEL

73

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 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 Diodos (CLAE-DAD). Após a otimização dos parâmetros de extração e separação dos compostos, o método foi validado avaliando-se curva analítica, linearidade, (more) 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 the optimization of the extraction and separation parameters, the method was validated by evaluating the analytical curve, linearity, limits of detection and quantification, pre (more) cision 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.

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

2009-01-01

74

A calorimetric study of carbamate formation  

International Nuclear Information System (INIS)

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

2011-01-01

75

Pesticidal Mixtures  

UK PubMed Central (United Kingdom)

Pesticidal mixtures comprising, as active components, 1) an anthranilamid compound of the formula I, 2 (I) Y wherein B1 is halogen, alkyl, haloalkyl, or haloalkoxy B2 is halogen, haloalkyl, alkoxy, haloalkoxy, alkenyloxy, alkynyloxy, alkylthio, haloalkylthio, alkylsulfinyl, haloalkylsulfinyl, alkylsulfonyl, haloalkylsulfonyl, alkyl-S(-O)[chi]-O- or haloalkyl S(O)x-O-, wherein x is 1 or 2 and the alkoxy radical may be substituted R is hydrogen, alkyl, alkenyl, alkynyl, cycloalkyl, wherein these groups arc optionally substituted X is halogen Y is H or halogen or the enantiomers or salts or N-oxides thereof, and 2) one or more compounds II selected from group A consisting of organo(thio)-phosphates, carbamates, pyrethroids, growth regulators, nicotinic receptor agonists/antagonists compounds, GABA antagonist compounds, macrocyclic lactone insecticides, METI I acaricides, METI II and III compounds, uncoupler compounds, oxidative phosphorylation inhibitor compounds, mixed function oxidase inhibitor compounds, sodium channel blocker compounds and others, all as defined in the description, in synergistically effective amounts, use of these mixture for combating insects, arachnids or nematodes in and on plants and for the protection of seeds, and for treating, controlling, preventing or protecting a warm-blooded animal or a fish against infestation or infection by parasites.

GEWEHR MARKUS; PUHL MICHAEL; DICKHAUT JOACHIM; BASTIAANS HENRICUS MARIA MARTINUS; ZELLER ALISSA; ANSPAUGH DOUGLAS D; KUHN DAVID; OLOUMI-SADEGHI HASSAN; ARMES NIGEL

76

Pesticidal Mixtures  

UK PubMed Central (United Kingdom)

Pesticidal mixtures comprising, as active components, 1) an anthranilamid compound of the formula I wherein Q is H, Cl, Cr, I, CN or methyl B1 is halogen, alkyl, haloalkyl, or haloalkoxy B2 is halogen, haloalkyl, alkoxy, haloalkoxy, alkenyloxy, alkynyloxy, alkylthio, haloalkylthio, alkylsulfinyl, haloalkylsulfinyl, alkylsulfonyl, haloalkylsulfonyl, alkyl-S(-O)x-O- or haloalkyl S(O)x-O-, wherein x is 1 or 2 and the alkoxy radical may be substituted, or C(Ri)-N-ORj, C(Ri)-N(RjRk), wherein Ri, Rj and Rk are alkyl R is hydrogen, alkyl, alkenyl, alkynyl, cycloalkyl, alkylene-cycloalkyl, wherein these groups are optionally substituted R1 is F, Cl, Br, methyl or trifluoromethyl or the enantiomers or salts or N-oxides thereof, n is 1, 2 or 3 and 2) one or more compounds II selected from group A consisting of organo(thio)-phosphates, carbamates, pyrethroids, growth regulators, nicotinic receptor agonists/antagonists compounds, GABA antagonist compounds, macrocyclic lactone insecticides, METI I acaricides, METI II and III compounds, uncoupler compounds, oxidative phosphorylation inhibitor compounds, mixed function oxidase inhibitor compounds, sodium channel blocker compounds and others, all as defined in the description, in synergistically effective amounts, use of these mixture for combating insects, arachnids or nematodes in and on plants and for the protection of seeds, and for treating, controlling, preventing or protecting a warm-blooded animal or a fish against infestation or infection by parasites.

GEWEHR MARKUS; PUHL MICHAEL; DICKHAUT JOACHIM; BASTIAANS HENRICUS MARIA MARTINUS; ANSPAUGH DOUGLAS D; KUHN DAVID G; OLOUMI-SADEGHI HASSAN; ARMES NIGEL

77

Photocatalytic oxidation of pesticide rinsate.  

UK PubMed Central (United Kingdom)

Pesticide rinsate has been considered as one of the major threats for the environment. In this study, photocatalysts such as TiO2 and O3 were used to promote the efficiency of direct UV photolysis to prevent such wastewater pollution. Carbofuran (a carbamate pesticide) and mevinphos (an organophosphate pesticide) with a concentration of 100 mg/L were selected as the test pesticide rinsates. Parent pesticide compound, COD, and microtoxicity analysis were employed to investigate the effect of photocatalyst on the degradation efficiency of pesticide in rinsate. It was found that the photocatalytic oxidation process (UV/O3, UV/TiO2) showed much higher COD removal and microtoxicity reduction efficiency for pesticide rinsate than did direct UV photolysis under the imposed conditions, suggesting that photocatalytic oxidation processes such as UV/O3 and UV/TiO2 could be a better alternative to treat pesticide rinsate. In addition, it was noted that increasing the initial pH of mevinphos rinsate to a basic level was required to reach higher COD removal efficiency and positive microtoxicity reduction efficiency while it was not necessary for the treatment of carbofuran rinsate.

Kuo WS

2002-01-01

78

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...

79

Electrochemical study of some insecticides deriving from carbamates in aprotic media  

International Nuclear Information System (INIS)

[en] 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.

2009-01-01

80

Development and validation of a routine multiresidue method for determining 140 pesticides in fruits and vegetables by gas chromatography/tandem quadrupole mass spectrometry.  

UK PubMed Central (United Kingdom)

A GC/tandem quadrupole MS/MS method was developed and validated for the determination of the residues of 140 pesticides in fruits and vegetables. Pesticides were extracted from samples by using a miniaturized acetonitrile-based extraction technique known as the quick, easy, cheap, effective, rugged, and safe (QuEChERS) method. Validation studies were carried out on carrots, tomatoes, and strawberries. In order to reduce systematic errors due to a matrix-induced effect, quantification was carried out using matrix-matched standard calibration curves. The recovery and precision results satisfied the European Union criteria (i.e., average recoveries were in the range 70-120% with RSDs < or = 20%) for 125 of the 140 pesticides at a spiking level of 0.01 mg/kg. At the higher spiking levels, there were just two instances of overall average recovery < 70% (chlorothalonil and captan). The measurement uncertainty was estimated following a "top down" approach as being 21 and 35%, on average, based on validation and ongoing recovery data, respectively (coverage factor k = 2, confidence level 95%). Practical application to 541 samples of apples, tomatoes, strawberries, cucumbers, currants, mushrooms, carrots, peppers, pears, onions, and gooseberries under strict QC conditions demonstrated the ruggedness of the total procedure.

Walorczyk S; Drozdzy?ski D

2011-09-01

 
 
 
 
81

ACTIVE CASPASE-3 DETECTION IN CARBAMATE BENDIOCARB TREATED RABBIT LIVER  

Directory of Open Access Journals (Sweden)

Full Text Available 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.w. Almost no caspase positive cells were detected in the untreated samples. After 10 days of bendiocarb treatment, numerous immunoreactive cells were present throughout the organ, most commonly around the portal tract (PT). Positive cells were still abundant at 20 days close to the central vein, with a decline at 30 days, at which point vacuoles were observed in some cells together with replacement fibrosis. We concluded that bendiocarb has moderate effect on increase of programmed cell death, particularly after short-term administration.

Eva Petrovová; Dávid Maženský; Lenka Luptáková; ?ubica Š?avová

2013-01-01

82

Carbamate poisoning and oxime treatment in children: a clinical and laboratory study.  

UK PubMed Central (United Kingdom)

OBJECTIVE: (1) Retrospective evaluation of the clinical course of carbamate poisoning and the effect of oxime therapy in children. (2) In vitro study of the effect of oximes on the reactivation of carbamylated cholinesterase. DESIGN: (1) Clinical survey: The records of 26 children intoxicated with carbamates were examined retrospectively. The poisoning agents in all cases were positively identified as methomyl or aldicarb by gas chromatography-mass spectrometry. (2) Laboratory study: The direct effect of obidoxime and of pralidoxime on acetylcholinesterase activity in vitro was investigated in normal human packed red blood cells pretreated with an organophosphate (paraoxon) or a carbamate (aldicarb or methomyl). CLINICAL SETTING: Pediatric intensive care unit of a teaching hospital. PATIENTS: Twenty-six infants and young children (aged 1 to 8 years) admitted to the pediatric intensive care unit with severe carbamate intoxication. INTERVENTIONS: All cases had been treated with repeated doses of atropine sulfate (0.05 mg/kg) administered every 5 to 10 minutes until muscarinic symptoms disappeared. Obidoxime chloride (Toxogonin, 6 mg/kg) was administered on admission, and again after 4 to 5 hours. RESULTS: Predominant symptoms were related to central nervous system and nicotinic effects. All the patients showed marked improvement within several hours and recovered completely within 24 hours. None of the children deteriorated and none showed exacerbation of cholinergic symptoms after obidoxime treatment. In vitro, oximes reactivated acetylcholinesterase inhibited with paraoxon, whereas no significant effect of oximes on carbamylated enzyme activity was observed. CONCLUSIONS: Based on the recovery of all cases, as compared with other reports of carbamate poisoning treated with atropine alone, it is concluded that, in the case of aldicarb or methomyl poisoning, oxime therapy apparently does not contribute to the recovery of poisoned patients. In cases of poisoning by an unknown pesticide or of mixed poisoning, oxime therapy can prove beneficial because no negative effects of the therapy can be discerned.

Lifshitz M; Rotenberg M; Sofer S; Tamiri T; Shahak E; Almog S

1994-04-01

83

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.  

Science.gov (United States)

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. The final method involved a QuEChERS-based sample preparation (without dSPE clean up) and full scan acquisition using alternating scan events without/with fragmentation, at a resolving power of 50,000. Analyte detection was based on extraction of the exact mass (±5 ppm) of the major adduct ion at the database retention time ±30 s and the presence of a second diagnostic ion. Various options for the additional ion were investigated and compared (other adduct ions, M + 1 or M + 2 isotopes, fragments). The two-ion approach for selective detection of the pesticides in the full scan data was compared with two alternative approaches based on response thresholds. Using the two-ion approach, the number of false positives out of 11,676 pesticide/commodity combinations targeted was 36 (0.3 %). The percentage of false negatives, assessed for 2,730 pesticide/commodity combinations, was 13 %, 3 %, and 1 % at the 0.01-, 0.05-, and 0.20-mg/kg level, respectively (slightly higher with fully automated detection). Following the SANCO/12495/2011 protocol for validation of screening methods, the screening detection limit was determined for 130 pesticides and found to be 0.01, 0.05, and ?0.20 mg/kg for 86, 30, and 14 pesticides, respectively. For the detected pesticides in the spiked samples, the ability for unambiguous identification according to EU criteria was evaluated. A proposal for adaption of the criteria was made. PMID:22664752

Mol, Hans G J; Zomer, Paul; de Koning, Maarten

2012-06-05

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 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

85

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

Science.gov (United States)

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

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

2010-05-05

86

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

UK PubMed Central (United Kingdom)

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

Trti?-Petrovi? T; Dordevi? J; Dujakovi? N; Kumri? K; Vasiljevi? T; Lausevi? M

2010-07-01

87

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

UK PubMed Central (United Kingdom)

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.

Frenzel T; Sochor H; Speer K; Uihlein M

2000-07-01

88

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.  

UK PubMed Central (United Kingdom)

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.

Lehotay SJ; de Kok A; Hiemstra M; Van Bodegraven P

2005-03-01

89

Neurotoxicity of pesticides: a brief review.  

UK PubMed Central (United Kingdom)

Pesticides are substances widely used to control unwanted pests such as insects, weeds, fungi and rodents. Most pesticides are not highly selective, and are also toxic to nontarget species, including humans. A number of pesticides can cause neurotoxicity. Insecticides, which kill insects by targeting their nervous system, have neurotoxic effect in mammals as well. This family of chemicals comprises the organophosphates, the carbamates, the pyrethroids, the organochlorines, and other compounds. Insecticides interfere with chemical neurotransmission or ion channels, and usually cause reversible neurotoxic effects, that could nevertheless be lethal. Some herbicides and fungicides have also been shown to possess neurotoxic properties. The effects of pesticides on the nervous system may be involved in their acute toxicity, as in case of most insecticides, or may contribute to chronic neurodegenerative disorders, most notably Parkinson's disease. This brief review highlights some of the main neurotoxic pesticides, their effects, and mechanisms of action.

Costa LG; Giordano G; Guizzetti M; Vitalone A

2008-01-01

90

PREPARATION OF CARBAMATES WITH SOLID CATALYSTS  

UK PubMed Central (United Kingdom)

Procedure for preparing carbamates comprising reaction between at least: an amine or polyamines, an organic carbonate of formula (OR)(OR')C=O, a catalyst formed at least by a support selected from among at least a metal oxide, a microporous material, a mesoporous material, an anionic laminar compound of the hydrotalcite type or derivatives thereof or an organic polymer and which may also contain a metal from groups 8, 9, 10 and 11 of the periodic system. The carbamates obtained may be converted into the corresponding isocyanates thereof.

CORMA CANOS AVELINO; JUAREZ MARIN RAQUEL; GARCIA GOMEZ HERMENEGILDO

91

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

UK PubMed Central (United Kingdom)

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 < 20%) were obtained for atrazine, chlorpyrifos, alpha- and beta-endosulfan, endosulfan sulfate, 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.

Dos Santos LG; Lourencetti C; Pinto AA; Pignati WA; Dores EF

2011-01-01

92

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

93

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

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; Vera L. Ferracini; Maria A. Rosa

2012-01-01

94

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

95

CARBAMATE-SUBSTITUTED DIAMINOPYRIMIDINES AND USE THEREOF  

UK PubMed Central (United Kingdom)

The invention relates to novel carbamate-substituted diaminopyrimidines, a method for producing them, their use alone or in combinations for treating and/or preventing diseases and their use for producing medicaments for treating and/or preventing diseases, in particular for treating and/or preventing cardiovascular diseases.

FOLLMANN MARKUS; STASCH JOHANNES-PETER; REDLICH GORDEN; ACKERSTAFF JENS; GRIEBENOW NILS; WUNDER FRANK; LI VOLKHART MIN-JIAN; MITTENDORF JOACHIM; JAUTELAT ROLF

96

Semi-automated liquid chromatography-mass spectrometry (LC-MS/MS) method for basic pesticides in wastewater effluents.  

UK PubMed Central (United Kingdom)

Effluent from wastewater treatment plants have been identified as an important source of micro-organic contaminants in the environment. An online high-performance liquid chromatography-heated electrospray ionization tandem mass spectrometric method was developed and validated for the determination of basic pesticides in effluent wastewaters. Most available methods for pesticide analysis of wastewater samples are time-consuming, require complex clean-up steps and are difficult to automate. The method developed used a simple solid-phase extraction clean-up for salt and lipid reduction. On-line sample pre-concentration was performed using a reversed phase (C(18)) column, and analytes were separated by back-flushing onto an analytical column (C(8)) with detection using QqQ MS. An option to increase MS resolution was exploited to minimize interference from endogenous compounds in the matrix. A better than unit mass resolution was used (Q1 full width half maximum (FWHM)?=?0.2 Da and Q3 FWHM?=?0.7 Da), which was as rugged as a unit resolution method, and improved signal/noise and better detection limits were achieved for the targeted basic pesticides. This method was applied to the determination of 11 pesticides, including methoxytriazine, chlorotriazines, chloroacetanilides, phenylurea and carbamate pesticides. The percentage recovery values for these pesticides using the online trapping column were within the range, 73-95%, with relative standard deviation (RSD) values <8.9%. The highest concentrations of these pesticides in wastewater effluents in County Cork, Ireland, were simazine (0.51 ?g/L), prometon (0.14 ?g/L), diuron (0.21 ?g/L) and atrazine (0.19 ?g/L).

Cahill MG; Caprioli G; Stack M; Vittori S; James KJ

2011-04-01

97

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

UK PubMed Central (United Kingdom)

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: 3h (800rpm), addition of 10% of sodium chloride, no addition of methanol as organic modifier, and 15min 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 <17%, n=30). Validated limits of quantification in matrix were between 0.02 and 1µgL(-1), depending on the compound. A specific experimental design was conducted to evaluate the measurement uncertainty, which was comprised between 13 and 51%, whatever the pesticide and the concentration level. The applicability of the SBSE-LD-LCMSMS method was evaluated by analyzing surface water samples and by comparing with conventional solid phase extraction-LC-MSMS procedure.

Margoum C; Guillemain C; Yang X; Coquery M

2013-11-01

98

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

99

A calorimetric study of carbamate formation  

Energy Technology Data Exchange (ETDEWEB)

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

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

2011-05-15

100

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

International Nuclear Information System (INIS)

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

2008-09-00

 
 
 
 
101

Pesticidal Mixtures Comprising Cyanosulfoximine Compounds  

UK PubMed Central (United Kingdom)

The present invention relates to pesticidal mixtures comprising as active components 1) at least one cyanosulfoximine compound I of the formula I wherein R1, R2 and G are defined as in the description and 2) at least one fungicidal compounds II selected from azoles, strobilurins, carboxamides, carbamates, heterocyclic and various other compounds as defined in the description, in synergistically effective amounts. The invention relates further to methods and use of these mixtures for combating insects, arachnids or nematodes and harmful fungis in and on plants, and for protecting such plants being infested with pests, especially also for protecting seeds.

BREUNINGER DELPHINE; BASTIAANS HENRICUS MARIA MARTINUS; VON DEYN WOLFGANG; POHLMAN MATTHIAS; LANGEWALD JUERGEN; HADEN EGON

102

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

UK PubMed Central (United Kingdom)

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

Botta F; Fauchon N; Blanchoud H; Chevreuil M; Guery B

2012-01-01

103

PROCESS FOR THE SYNTHESIS OF CYCLIC CARBAMATES  

UK PubMed Central (United Kingdom)

The invention is directed to a process for the preparation of a cyclic carbamate starting with a chiral propargylic alcohol and/or a suitable salt thereof, which is reacted with a cyclisation agent selected from phosgene, diphosgene, triphosgene and mixtures thereof, and in that the reaction is carried out in the presence of an aqueous base, and a water-immiscible organic solvent, said organic solvent mainly comprising at least one compound selected from C2-5-alkyl C2-5-carboxylates and mixtures of at least one C2-5-alkyl C2-5-carboxylate with at least one C5-8-alkane. Another aspect of the invention is directed to a process for the synthesis of said cyclic carbamate starting described above, wherein also a process for the preparation of the chiral propargylic alcohol is provided.

BRENNER MEINRAD; CARREIRA ERICK M; CHINKOV NICKA; LORENZI MIRIAM; WARM ALEKSANDER; ZIMMERMANN LOTHAR

104

Plant epicuticular lipids: alteration by herbicidal carbamates.  

Science.gov (United States)

The effect of several carbamates and trichloroacetic acid on the biosynthesis of epicuticular lipids from leaves of pea (Pisum sativum) was tested by chemical and visual methods. The carbamates tested included S-(2,3-dichloroallyl) diisopropylthiocarbamate (diallate), N-(3-chlorophenyl) isopropylcarbamate (chloropropham), S-ethyl dipropylthiocarbamate, and 2-chloroallyl diethyldithiocarbamate. Diallate reduced epicuticular lipids by 50% when the plants were root-treated and by 80% when vapor-treated. These results were supported by scanning electron microscopy and carbon replica techniques with transmission electron microscopy. The ratio of wax lipid components in the diallate-treated plants remained unchanged, with the exception of the primary alcohols, which were reduced. Diallate appears to interfere with the biosynthesis of a precursor to the elongation-decarboxylation pathway of lipid synthesis. N-(3-Chlorophenyl)isopropylcarbamate had no significant effect on total amounts of extractable epicuticular lipids, nor did it alter the structure of the wax formation on the leaves. The scanning electron microscopy micrographs indicated that S-ethyl dipropylthiocarbamate significantly reduced wax formation on pea leaves. 2-Chloroallyl diethyldithiocarbamate altered the structure of the wax formations, but not the total amount of wax (scanning electron microscopy). Trichloroacetic acid had little effect on wax deposition compared to diallate or S-ethyl dipropylthiocarbamate (scanning electron microscopy). The implication of the effect of the carbamates on epicuticular lipids and penetration of subsequent topically applied chemicals is discussed. PMID:16657455

Still, G G; Davis, D G; Zander, G L

1970-08-01

105

Plant epicuticular lipids: alteration by herbicidal carbamates.  

UK PubMed Central (United Kingdom)

The effect of several carbamates and trichloroacetic acid on the biosynthesis of epicuticular lipids from leaves of pea (Pisum sativum) was tested by chemical and visual methods. The carbamates tested included S-(2,3-dichloroallyl) diisopropylthiocarbamate (diallate), N-(3-chlorophenyl) isopropylcarbamate (chloropropham), S-ethyl dipropylthiocarbamate, and 2-chloroallyl diethyldithiocarbamate. Diallate reduced epicuticular lipids by 50% when the plants were root-treated and by 80% when vapor-treated. These results were supported by scanning electron microscopy and carbon replica techniques with transmission electron microscopy. The ratio of wax lipid components in the diallate-treated plants remained unchanged, with the exception of the primary alcohols, which were reduced. Diallate appears to interfere with the biosynthesis of a precursor to the elongation-decarboxylation pathway of lipid synthesis. N-(3-Chlorophenyl)isopropylcarbamate had no significant effect on total amounts of extractable epicuticular lipids, nor did it alter the structure of the wax formation on the leaves. The scanning electron microscopy micrographs indicated that S-ethyl dipropylthiocarbamate significantly reduced wax formation on pea leaves. 2-Chloroallyl diethyldithiocarbamate altered the structure of the wax formations, but not the total amount of wax (scanning electron microscopy). Trichloroacetic acid had little effect on wax deposition compared to diallate or S-ethyl dipropylthiocarbamate (scanning electron microscopy). The implication of the effect of the carbamates on epicuticular lipids and penetration of subsequent topically applied chemicals is discussed.

Still GG; Davis DG; Zander GL

1970-08-01

106

Compounded pesticide  

UK PubMed Central (United Kingdom)

The invention provides a compounded pesticide, and relates to the field of compounded pesticide. The compounded pesticide is formed by compounding imidacloprid, buprofezin and fillings, and the pesticide comprises the following compositions in percentage by weight: 4 to 6 percent of a mixture of imidacloprid and buprofezin and the balance of filling. The compounded pesticide is characterized in that the pesticide is a novel efficient broad-spectrum powder pesticide capable of resisting rainwash and has convenient storage and transportation and longer shelf life the pesticide has the advantages of functions of stomachtoxicity, contact killing and intake transportation, quick knock down force, long lasting period and the like, thereby effectively controlling pests such as rice hoppers thepesticide not only retains the advantages of a single pesticide, but also reduces the dosage of the single pesticide, substantially increases pesticide effect and saves cost after being compounded inthe proportion.

ZHANGLIANG DONG

107

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

UK PubMed Central (United Kingdom)

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

Anagnostopoulos C; Miliadis GE

2013-08-01

108

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

Science.gov (United States)

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

Anagnostopoulos, C; Miliadis, G E

2013-03-27

109

METHOD FOR PRODUCING FLUORINATED CARBAMATES AND ISOCYANATES WITH HETEROGENEOUS CATALYSTS  

UK PubMed Central (United Kingdom)

Method for producing fluorinated carbamates that comprises the reaction between an amine or polyamine and a fluorinated carbonate in the presence of a catalyst in the presence of basic heterogeneous catalysts. The method may also comprise an additional step in which the carbamates are converted into the corresponding isocyanates.

PADILLA POLO ANA; CORMA CANOS AVELINO; GARCIA GOMEZ HERMENEGILDO; JUAREZ MARIN RAQUEL

110

Compounded pesticide  

UK PubMed Central (United Kingdom)

The invention provides a compounded pesticide, and relates to the field of compounded pesticide. The compounded pesticide is formed by compounding monosultap, buprofezin and fillings, and the pesticide comprises the following compositions in percentage by weight: 62 to 63 percent of monosultap, 12 to 13 percent of buprofezin, and the balance of fillings. The compounded pesticide has the advantagesthat the pesticide is a novel efficient broad-spectrum powder pesticide capable of resisting rainwash and has convenient storage and transportation and longer shelf life the pesticide has the functions of stomachtoxicity, contact killing and intake transportation as well as quick knock down force and long lasting period, thereby effectively controlling pests such as rice stem borers and rice hoppers the pesticide not only retains the advantages of a single pesticide, but also reduces the dosage of the single pesticide, substantially increases pesticide effect and saves cost after being compounded in the proportion the pesticide causes less pollution to ecological environment and less stimulation in human skin and eyes and is propitious to the protection of livestock safety and the pesticide also delays pesticide resistance to pests and is suitable for long-term use.

ZHANGLIANG DONG

111

PROCESS FOR THE SYNTHESIS OF CYCLIC CARBAMATES  

UK PubMed Central (United Kingdom)

The invention is directed to a process for the preparation of a cyclic carbamate starting with o-aminobenzyl alcohol and/or a suitable salt thereof, which is reacted with a cyclisation agent selected from phosgene, diphosgene, triphosgene and mixtures thereof, and in that the reaction carried out in the presence of an aqueous base, and a water-immiscible organic solvent, said organic solvent mainly comprising at least one compound selected from C2-5-alkyl C2-5-carboxylates and mixtures of at least one C2-5-alkyl C2-5-carboxylate with at least one C5-8-alkane.

BRENNER MEINRAD; CARREIRA ERICK M; CHINKOV NICKA; LORENZI MIRIAM; WARM ALEKSANDER; ZIMMERMANN LOTHAR

112

Process for the synthesis of cyclic carbamates  

UK PubMed Central (United Kingdom)

The invention is directed to a process for the preparation of a cyclic carbamate starting with o- aminobenzyl alcohol and/or a suitable salt thereof, which is reacted with a cyclisation agent selected from phosgene, diphosgene, triphosgene and mixtures thereof, and in that the reaction is carried out in the presence of an aqueous base, and a water-immiscible organic solvent, said organic solvent mainly comprising at least one compound selected from C 2-5 -alkyl C 2-5 -carboxylates and mixtures of at least one C 2-5 -alkyl C 2-5 -carboxylate with at least one C 5-8 -alkane.

113

PREPARATION OF CARBAMATES WITH SOLID CATALYSTS  

UK PubMed Central (United Kingdom)

Carbamate preparation process comprising, the reaction between at least: an amine or polyamines, an organic carbonate of formula (OR)(OR')C-O, a catalyst which is formed by at least a support selected from at least a metal oxide, a microporous material, a mesoporous material, an anionic laminar compound of hydrotalcite type or their derivatives or an organic polymer and which may further contain a metal from groups 8, 9, 10 and 11 of the periodical system. The carbonates obtained can be transformed in their corresponding isocyanates.

CORMA CANOS AVELINO; JUAREZ MARIN RAQUEL; GARCIA GOMEZ HERMENEGILDO

114

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

UK PubMed Central (United Kingdom)

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

Lozano A; Rajski ?; Belmonte-Valles N; Uclés A; Uclés S; Mezcua M; Fernández-Alba AR

2012-12-01

115

Increasing pesticide-resistant ectoparasitic infections may increase pesticide poisoning risks in children.  

Science.gov (United States)

Head louse and scabies mite infestations are common among pre-school and school-age children, and topical pesticides are frequently prescribed to treat such conditions. Ectoparasite resistance to the safest and most commonly prescribed pyrethrin/pyrethroid pesticides for ectoparasitic infections has, however, been increasing since the 1980s. The increasing resistance of these arthropods to the safest pesticides may lead to greater use of more toxic, alternative pesticides to control infestations and to prevent institutional outbreaks. MEDLINE and Cochrane searches, 1966-2008, were conducted to assess the impact of increasing pesticide resistance on prescribing practices for ectoparasitic infections and to describe the evolving global epidemiology of pediatric poisonings by more toxic pediculicides and miticides, including carbamates, organochlorines, and organophosphates. Pharmacists, physicians, and poison control personnel should be fully informed about increasing pesticide resistance among the most commonly encountered ectoparasites of children and the institutionalized and be prepared to prevent and to treat accidental home and institutional pesticide poisonings with more toxic pesticides. PMID:18828463

Diaz, James H

116

Increasing pesticide-resistant ectoparasitic infections may increase pesticide poisoning risks in children.  

UK PubMed Central (United Kingdom)

Head louse and scabies mite infestations are common among pre-school and school-age children, and topical pesticides are frequently prescribed to treat such conditions. Ectoparasite resistance to the safest and most commonly prescribed pyrethrin/pyrethroid pesticides for ectoparasitic infections has, however, been increasing since the 1980s. The increasing resistance of these arthropods to the safest pesticides may lead to greater use of more toxic, alternative pesticides to control infestations and to prevent institutional outbreaks. MEDLINE and Cochrane searches, 1966-2008, were conducted to assess the impact of increasing pesticide resistance on prescribing practices for ectoparasitic infections and to describe the evolving global epidemiology of pediatric poisonings by more toxic pediculicides and miticides, including carbamates, organochlorines, and organophosphates. Pharmacists, physicians, and poison control personnel should be fully informed about increasing pesticide resistance among the most commonly encountered ectoparasites of children and the institutionalized and be prepared to prevent and to treat accidental home and institutional pesticide poisonings with more toxic pesticides.

Diaz JH

2008-07-01

117

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

Scientific Electronic Library Online (English)

Full Text Available Abstract in english This paper presents a practical and rapid method which was validated for simultaneous quantification and confirmation of 29 pesticides in fruits and vegetables using ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The samples were extracted following the method known 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 (more) 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%.

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

2012-01-01

118

Environmental impact of pesticides in Egypt.  

UK PubMed Central (United Kingdom)

The first use of petroleum-derived pesticides in Egyptian agriculture was initiated in 1950. Early applications consisted of distributing insecticidal dusts containing DDT/BHC/S onto cotton fields. This practice was followed by use of toxaphene until 1961. Carbamates, organophosphates, and synthetic pyrethroids were subsequently used, mainly for applications to cotton. In addition to the use of about 1 million metric tons (t) of pesticides in the agricultural sector over a 50-yr period, specific health and environmental problems are documented in this review. Major problems represented and discussed in this review are human poisoning, incidental toxicity to farm animals, insect pest resistance, destruction of beneficial parasites and predators, contamination of food by pesticide residues, and pollution of environmental ecosystems. Several reports reveal that chlorinated hydrocarbon pesticide residues are still detectable in several environmental compartments; however, these residues are in decline. Since 1990, there is a growing movement toward reduced consumption of traditional pesticides and a tendency to expand use of biopesticides, including "Bt," and plant incorporated protectants (PIPs). On the other hand, DDT and lindane were used for indoor and hygienic purposes as early as 1952. Presently, indoor use of pesticides for pest control is widespread in Egypt. Accurate information concerning the types and amounts of Egyptian household pesticide use, or numbers of poisoning or contamination incidents, is unavailable. Generally, use of indoor pesticides is inadequately managed. The results of a survey of Egyptian farmers' attitudes toward pesticides and their behavior in using them garnered new insights as to how pesticides should be better controlled and regulated in Egypt.

Mansour SA

2008-01-01

119

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

Scientific Electronic Library Online (English)

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

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

2010-01-01

120

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 ...

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

 
 
 
 
121

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)

1963-01-01

122

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

UK PubMed Central (United Kingdom)

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.

Dabrowski JM; Balderacchi M

2013-09-01

123

Pesticidal Mixtures  

UK PubMed Central (United Kingdom)

Pesticidal mixtures comprising, as active components, 1) a malonodinitrile compound selected from compounds I-1 to I-8 CF2HCF2CF2CF2CH2C(CN)2CH2CH2CF3 (compound I-1 name: 2-(2,2,3,3,4,4,5,5-octofluoro-pentyl)-2-(3,3,3-trifluoro-propyl)-malononitrile) CF3(CH2)2C(CN)2CH2(CF2)5CF2H (compound I-2 name: 2-(2,2,3,3,4,4,5,5,6,6,7,7-dodecafluoro-heptyl)-2-(3,3,3-trifluoro-propyl)-malononitrile) CF3(CH2)2C(CN)2(CH2)2C(CF3)2F (compound I-3 name: 2-(3,4,4,4-tetrafluoro-3-trifluoromethyl-butyl)-2-(3,3,3-trifluoro-propyl)-malononitrile) CF3(CH2)2C(CN)2(CH2)2(CF2)3CF3 (compound I-4 name: 2-(3,3,4,4,5,5,6,6,6-nonafluoro-hexyl)-2-(3,3,3-trifluoro-propyl)-malononitrile) CF2H(CF2)3CH2C(CN)2CH2(CF2)3CF2H (compound I-5 name: 2,2-bis-(2,2,3,3,4,4,5,5-octafluoro-pentyl)-malononitrile) CF3(CH2)2C(CN)2CH2(CF2)3CF3 (compound I-6 name: 2-(2,2,3,3,4,4,5,5,5-nonafluoro-pentyl)-2-(3,3,3-trifluoro-propyl)-malononitrile) CF3(CF2)2CH2C(CN)2CH2(CF2)3CF2H (compound I-7 name: 2-(2,2,3,3,4,4,4-heptafluoro-butyl)-2-(2,2,3,3,4,4,5,5-octafluoro-pentyl)-malononitrile) or CF3CF2CH2C(CN)2CH2(CF2)3CF2H (compound I-8 name: 2-(2,2,3,3,4,4,5,5-octafluoro-pentyl)-2-(2,2,3,3,3-pentafluoro-propyl)-malononitrile) and 2) one or more compounds II selected from group A consisting of organo(thio)-phosphates, carbamates, pyrethroids, growth regulators, nicotinic receptor agonists/antagonists compounds, GABA antagonist compounds, macrocyclic lactone insecticides, METI I acaricides, METI II and III compounds, uncoupler compounds, oxidative phosphorylation inhibitor compounds, mixed function oxidase inhibitor compounds, sodium channel blocker compounds and others, all as defined in the description, in synergistically effective amounts, use of these mixture for combating insects, arachnids or nematodes in and on plants and for the protection of seeds, and for treating, controlling, preventing or protecting a warm-blooded animal or a fish against infestation or infection by parasites.

LANGEWALD JUERGEN; COTTER HENRY VAN TUYL; CULBERTSON DEBORAH L; OLOUMI-SADEGHI HASSAN

124

PESTICIDAL MIXTURES COMPRISING ISOXAZOLINE COMPOUNDS II  

UK PubMed Central (United Kingdom)

The present invention relates to pesticidal mixtures comprising as active components 1) at least one isoxazoline compound I of the formula (I) wherein R1, R2, R3, R4, R5 and A are defined as in the description and 2) at least one fungicidal compounds Il selected from azoles, strobilurins, carboxamides, carbamates, heterocyclic and various other compounds as defined in the description, in synergistically effective amounts. The invention relates further to methods and use of these mixtures for combating insects, arachnids or nematodes and harmful fungis in and on plants, and for protecting such plants being infested with pests, especially also for protecting seeds.

KOERBER KARSTEN; KAISER FLORIAN; HADEN EGON

125

Pesticidal Mixtures Comprising Isoxazoline Compounds II  

UK PubMed Central (United Kingdom)

The present invention relates to pesticidal mixtures comprising as active components 1) at least one isoxazoline compound I of the formula I wherein R1, R2, R3, R4, R5 and A are defined as in the description and 2) at least one fungicidal compounds II selected from azoles, strobilurins, carboxamides, carbamates, heterocyclic and various other compounds as defined in the description, in synergistically effective amounts. The invention relates further to methods and use of these mixtures for combating insects, arachnids or nematodes and harmful fungis in and on plants, and for protecting such plants being infested with pests, especially also for protecting seeds.

KOERBER KARSTEN; KAISER FLORIAN; HADEN EGON

126

Pesticide Consumer Alerts  

Science.gov (United States)

... are here: EPA Home Pesticides Pesticide Alerts Pesticide Alerts Questions on Pesticides? National Pesticide Information Center (NPIC) ... gov - Information consolidated from 6 federal agencies to alert the public to government product recalls. Mouse and ...

127

METHOD FOR PRODUCING ISOCYANATES BY THERMALLY SPLITTING CARBAMATES  

UK PubMed Central (United Kingdom)

The invention relates to a method for producing isocyanates by thermally splitting carbamates, also known as carbamide acid ester or urethane. The carbamate splitting increases in significance as a phosgene-free method for producing isocyanates. Various apparatuses are proposed for technically performing the carbamate splitting, in particular columns (in EP 0 795 543), fluidized bed reactors (in EP 555 628 and in DE 199 07 648), falling film evaporators or thin film evaporators (in EP 0 092 738). The carbamate splitting can be carried out in the liquid or gas phase. The formation of high molecular weight byproducts is problematic when thermally splitting carbamates, said byproducts arising from continued reaction of the splitting products with themselves or with the initial materials. Said byproducts can lead to deposits in the apparatuses, thus limiting continuous operation and leading to loss of yield. The residues comprise in particular allophanates and isocyanurates. The byproducts also arise by the reaction of half-urethanes (semicarbamates, that is, a difunctional compound comprising a urethane and an isocyanate function, intermediate to splitting bisurethanes) with themselves. In order to prevent said problems, the split products isocyanate and alcohol must be separated from the carbamate split gas as quickly as possible. It is further known that the problems of back reaction and continued reaction are reduced in the course of splitting, in that the carbamate split is performed in the presence of solvents, because the reaction speed of the back reaction of isocyanate and alcohol (urethanization) and the continued reactions is dependent on the type of solvent and the dilution by the solvent. For example, J.H. Saunders and K.C. Frisch: Polyurethanes, Chemistry and Technology, 1962, P. 146, Table 10, Data on the reactivity of isocyanates having alcohols in the presence of different solvents.

BOCK MICHAEL; FRANZKE AXEL; BAUMANN ROBERT; STROEFER ECKHARD

128

[The use of acetylcholinesterase inhibitors pesticides in eleven local health institutions, Colombia, 2002-2005].  

UK PubMed Central (United Kingdom)

INTRODUCTION: Due to the importance of acetylcholinesterase inhibiting chemicals as pesticides in developing countries, the Instituto Nacional de Salud in Colombia designed the organophosphate and carbamate epidemiological surveillance program for the period 2002-2005. OBJECTIVE: The acetylcholinesterase activity was determined in study participants with a history of organophosphate and carbamate exposure and the most commonly used pesticides were identified in each study area. MATERIALS AND METHODS: The information was compiled from reports sent to the Instituto Nacional de Salud organophosphate and carbamate epidemiological surveillance program from each of 11 provinces in Colombia. The analytical determination of the biomarker was performed by acetylcholinestare activity determined with the Lovibond field equipment. RESULTS: A total of 28,303 people were designated as having risk of exposure to pesticides. Most were men (81.4%). Abnormal determinations averaged 9.3% (9.9% in men and 7.0% in women). The 18-25 year old age group showed the highest prevalence of abnormal results (12.3%), followed by the group of 0-5 year olds (10.7%). The highest prevalence of abnormal acetylcholinesterase activity was in farm workers (27.0%), followed by general outdoor activities (26.1%). In the province of Meta, 80% of participants showed abnormal values of enzyme activity. The most commonly used pesticides were organophosphates (39.7%) and carbamates (16.6%). CONCLUSION: The increase in the prevalence of abnormal values of acetylcholinesterase activity and the risk of exposure to pesticides in children necessitates a lowering of use and commercialization of high risk pesticides, and a need for developing safer methods for pest management.

Cárdenas O; Silva E; Ortiz JE

2010-01-01

129

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

130

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

131

Gliomas and Farm Pesticide Exposure in Women: The Upper Midwest Health Study  

Science.gov (United States)

An excess incidence of brain cancer in male farmers has been noted in several studies, but few studies have focused on women. The National Institute for Occupational Safety and Health Upper Midwest Health Study evaluated effects of rural exposures for 341 female glioma cases and 528 controls, all adult (18–80 years of age) nonmetropolitan residents of Iowa, Michigan, Minnesota, and Wisconsin. On average, controls lived longer on farms than did cases. After adjusting for age, age group, education, and farm residence, no association with glioma was observed for exposure to arsenicals, benzoic acids, carbamates, chloroacetanilides, dinitroanilines, inorganics, organochlorines, organophosphates, phenoxys, triazines, or urea-based or estrogenic pesticides. An increased risk of glioma was observed for carbamate herbicides but was not statistically significant (odds ratio = 3.0; 95% confidence interval, 0.9–9.5). No association was observed between glioma and exposure to 12 widely used specific pesticides, after adjustment for age, age group, education, and any other pesticide exposure. These results were not affected after exclusion of proxy respondents (43% of cases, 2% of controls). Women were less likely than men to have applied pesticides, but more likely to have laundered pesticide-contaminated clothes. Storing pesticides in the house was associated with a statistically non-significant increased risk. Results show that exposure to pesticides was not associated with an increased risk of intracranial gliomas in women. Other farm-related factors could be etiologic factors and will be discussed in future reports.

Carreon, Tania; Butler, Mary Ann; Ruder, Avima M.; Waters, Martha A.; Davis-King, Karen E.; Calvert, Geoffrey M.; Schulte, Paul A.; Connally, Barbara; Ward, Elizabeth M.; Sanderson, Wayne T.; Heineman, Ellen F.; Mandel, Jack S.; Morton, Roscoe F.; Reding, Douglas J.; Rosenman, Kenneth D.; Talaska, Glenn

2005-01-01

132

Gliomas and farm pesticide exposure in women: the Upper Midwest Health Study.  

UK PubMed Central (United Kingdom)

An excess incidence of brain cancer in male farmers has been noted in several studies, but few studies have focused on women. The National Institute for Occupational Safety and Health Upper Midwest Health Study evaluated effects of rural exposures for 341 female glioma cases and 528 controls, all adult (18-80 years of age) nonmetropolitan residents of Iowa, Michigan, Minnesota, and Wisconsin. On average, controls lived longer on farms than did cases. After adjusting for age, age group, education, and farm residence, no association with glioma was observed for exposure to arsenicals, benzoic acids, carbamates, chloroacetanilides, dinitroanilines, inorganics, organochlorines, organophosphates, phenoxys, triazines, or urea-based or estrogenic pesticides. An increased risk of glioma was observed for carbamate herbicides but was not statistically significant (odds ratio = 3.0; 95% confidence interval, 0.9-9.5). No association was observed between glioma and exposure to 12 widely used specific pesticides, after adjustment for age, age group, education, and any other pesticide exposure. These results were not affected after exclusion of proxy respondents (43% of cases, 2% of controls). Women were less likely than men to have applied pesticides, but more likely to have laundered pesticide-contaminated clothes. Storing pesticides in the house was associated with a statistically non-significant increased risk. Results show that exposure to pesticides was not associated with an increased risk of intracranial gliomas in women. Other farm-related factors could be etiologic factors and will be discussed in future reports.

Carreón T; Butler MA; Ruder AM; Waters MA; Davis-King KE; Calvert GM; Schulte PA; Connally B; Ward EM; Sanderson WT; Heineman EF; Mandel JS; Morton RF; Reding DJ; Rosenman KD; Talaska G

2005-05-01

133

Effect of long-term exposure to pesticides on plasma esterases from plastic greenhouse workers.  

Science.gov (United States)

Previous reports in animals considered beta-glucuronidase activity as a novel biomarker of anticholinesterase (organophosphates and carbamates) pesticides exposure. Acid phosphatase activity was also shown to increase after organophosphates exposure. In addition, there is evidence that the paraoxonase status influences sensitivity to specific pesticides. In this study, activities of beta-glucuronidase, acid phosphatase, cholinesterase, and paraoxonase were measured in plasma from plastic greenhouse workers exposed over the long term to different pesticides, including organophosphates and carbamates, in order to evaluate the potential chronic toxicity of pesticides at occupational level. Our results show that activities of paraoxonase and cholinesterase were decreased in applicators of pesticides compared to non-applicators. Likewise, it was found that activities of beta-glucuronidase and acid phosphatase were associated with pesticide exposure in humans, and that both biochemical parameters were related to each other. Interestingly, the paraoxonase B allele (phenotyped in plasma) was associated with a higher risk of inhibition of cholinesterase activity above a 25% level, which supports the hypothesis that paraoxonase phenotypes are associated with susceptibility of humans to anticholinesterase pesticides toxicity. PMID:15205026

Hernández, Antonio; Gómez, M Amparo; Pena, Gloria; Gil, Fernando; Rodrigo, Lourdes; Villanueva, Enrique; Pla, Antonio

2004-07-23

134

PESTICIDAL PROTEINS  

UK PubMed Central (United Kingdom)

The subject invention concerns new classes of pesticidally active proteins and the polynucleotide sequences that encode these proteins. In preferred embodiments, these pesticidal proteins have molecular weights of approximately 40-50 kDa and of approximately 10-15 kDa.

NARVA KENNETH E; SCHNEPF H. ERNEST; KNUTH MARK; POLLARD MICHAEL R; CARDINEAU GUY A; SCHWAB GEORGE E; MICHAELS TRACY ELLIS; FINSTAD LEE STACY; DIEHL PAULA; DOJILLO JOANNA; STAMP LISA; HERMAN ROD A

135

Pesticidal proteins  

UK PubMed Central (United Kingdom)

The subject invention concerns new classes of pesticidally active proteins and the polynucleotide sequences that encode these proteins. In preferred embodiments, these pesticidal protein have molecular weights of approximately 40-50 kDa and of approximately 10-15 kDa.

NARVA KENNETH E; SCHNEPF H. ERNEST; KNUTH MARK; POLLARD MICHAEL R; CARDINEAU GUY A; SCHWAB GEORGE E; MICHAELS TRACY ELLIS; LEE STACEY FINSTAD; DIEHL PAULA; DOJILLO JOANNA; STAMP LISA; HERMAN ROD

136

Pesticidal proteins  

UK PubMed Central (United Kingdom)

The subject invention concerns new classes of pesticidally active proteins and the polynucleotide sequences that encode these proteins. In preferred embodiments, these pesticidal proteins have molecular weights of approximately 40-50 kDa and of approximately 10-15 kDa.

NARVA KENNETH E; SCHNEPF H. ERNEST; KNUTH MARK; POLLARD MICHAEL R; CARDINEAU GUY A; SCHWAB GEORGE E; MICHAELS TRACY ELLIS; LEE STACEY FINSTAD; DIEHL PAULA; DOJILLO JOANNA; STAMP LISA; HERMAN ROD

137

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

Directory of Open Access Journals (Sweden)

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

Lacassie Éric; Marquet Pierre; Gaulier Jean-Michel; Dreyfuss Marie-Françoise; Lachâtre Gérard

2009-01-01

138

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

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

S Austin Richard; Elizabeth A Frank; Cletus J M D’Souza

2013-01-01

139

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

Scientific Electronic Library Online (English)

Full Text Available 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 ex (more) trato 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:petroleum benzine (1:1). The volume was centrifuged and was then filtered under Na2SO4. One milliliter of organic extract was concentrated then diluted in isooctane and one (more) 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.

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

2010-05-01

140

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

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

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

2010-01-01

 
 
 
 
141

Pesticide Warning  

Medline Plus

Full Text Available ... studies suggests pesticides, like the common bug and weed killers used by millions, are associated with a ... According to the data, exposure to bug or weed killers, and solvents, increased the risk of developing ...

142

A Novel Approach for Evaluating Carbamate Mixtures for Dose Additivity  

Science.gov (United States)

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

143

SUBSTITUTED METHYL-PYRIMIDIN-5-YL CARBAMATES AND USE THEREOF  

UK PubMed Central (United Kingdom)

The invention relates to novel, substituted methyl-pyrimidin-5-yl carbamates, a method for producing them, their use alone or in combinations for treating and/or preventing diseases and to their use for producing medicaments for treating and/or preventing diseases, in particular for treating and/or preventing cardiovascular diseases.

FOLLMANN MARKUS; STASCH JOHANNES-PETER; REDLICH GORDEN; ACKERSTAFF JENS; GRIEBENOW NILS; KNORR ANDREAS; WUNDER FRANK; LI VOLKHART MIN-JIAN; SCHIROK HARTMUT; JAUTELAT ROLF

144

Dog poisoning with furadan 35-ST (carbamate insecticide)  

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

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

2011-01-01

145

Synthesis of camptothecin-amino acid carbamate linkers.  

Science.gov (United States)

A more convenient and facile approach for the synthesis and production of camptothecin-amino acids carbamate linkers, that can be used in the synthesis of bioconjugate peptides JF-10-81, JF-10-71, and other peptide analogs designed to target somatostatin receptors has been described. PMID:21431932

Etienne, Marcus A; Kostochka, Mikhail; Fuselier, Joseph A; Coy, David H

2011-03-24

146

Synthesis of camptothecin-amino acid carbamate linkers.  

UK PubMed Central (United Kingdom)

A more convenient and facile approach for the synthesis and production of camptothecin-amino acids carbamate linkers, that can be used in the synthesis of bioconjugate peptides JF-10-81, JF-10-71, and other peptide analogs designed to target somatostatin receptors has been described.

Etienne MA; Kostochka M; Fuselier JA; Coy DH

2012-05-01

147

Pesticide Poisoning  

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

Neva Sataloglu; Berna Aydin; Ahmet Turla

2007-01-01

148

Pesticide Poisoning  

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

Neva Sataloglu; Berna Aydin; Ahmet Turla

2007-01-01

149

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

Science.gov (United States)

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

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

150

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

2010-03-12

151

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.  

UK PubMed Central (United Kingdom)

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.

Caldas SS; Costa FP; Primel EG

2010-04-01

152

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

UK PubMed Central (United Kingdom)

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 <20%, except for 10 pesticides that had recoveries of 50-70% and two with 120-130%. Low limits of detection (0.003-0.04?g/g) and quantification (0.005-0.05?g/g) were readily achieved with this method for all tested pesticides. A "top down" empirical model was used to estimate the expanded uncertainty at 28% on average (coverage factor k=2, confidence level 95%). The MSPD method was successfully used on real bee samples to analyse four acaricides, 55 fungicides, 16 herbicides and 78 insecticides from various regions of Poland. A total of 33 honeybee samples from suspected pesticide poisoning incidents were analysed, in which 17 different pesticides were determined (14 insecticides and three fungicides). The pesticides most often found in honeybees were 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).

Lozowicka B

2013-07-01

153

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 <20%, except for 10 pesticides that had recoveries of 50-70% and two with 120-130%. Low limits of detection (0.003-0.04?g/g) and quantification (0.005-0.05?g/g) were readily achieved with this method for all tested pesticides. A "top down" empirical model was used to estimate the expanded uncertainty at 28% on average (coverage factor k=2, confidence level 95%). The MSPD method was successfully used on real bee samples to analyse four acaricides, 55 fungicides, 16 herbicides and 78 insecticides from various regions of Poland. A total of 33 honeybee samples from suspected pesticide poisoning incidents were analysed, in which 17 different pesticides were determined (14 insecticides and three fungicides). The pesticides most often found in honeybees were 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

Lozowicka, Bo?ena

2013-07-31

154

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

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

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

2007-01-01

155

Surveying of Pesticides Commonly on the Markets of Iran in 2009  

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

Rouhullah Dehghani; Seyed G. Moosavi; Hadi Esalmi; Malihe Mohammadi; Zahra Jalali; Nargess Zamini

2011-01-01

156

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

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

2009-12-16

157

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.  

UK PubMed Central (United Kingdom)

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.

Menezes Filho A; dos Santos FN; Pereira PA

2010-04-01

158

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 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 acetato de etilo- ciclohexano (1:1). Los extractos se limpiaron posteriormente por cromatografía de permeación en gel para eliminar principalmente grasa y cromatografía e (more) n 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 acetate-cyclohexane (1:1) partitioning. The clean up steps include gel permeation chromatography and mini column chromatography using silicagel. Final determination was carried out (more) 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.

Dallos Corredor, David; Guerrero Dallos, Jairo Arturo

2005-12-01

159

The formation of carbamate ions in interstellar ice analogues.  

UK PubMed Central (United Kingdom)

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.

Rodríguez-Lazcano Y; Maté B; Herrero VJ; Escribano R; Gálvez O

2013-10-01

160

Organocatalytic Knoevenagel condensations by means of carbamic acid ammonium salts.  

UK PubMed Central (United Kingdom)

The Knoevenagel condensation between an active methylene compound and an aromatic aldehyde with a carbamic acid ammonium salt used as an organocatalyst gave the desired Knoevenagel products in up to 98% yield. The reaction occurred at rt and in a short reaction time under solvent-free conditions. In addition, no extraction, wash, or chromatography steps were needed to obtain a high-purity Knoevenagel product.

Mase N; Horibe T

2013-04-01

 
 
 
 
161

Pesticidal Mixtures Comprising Cyanosulfoximine Compounds and Spinetoram  

UK PubMed Central (United Kingdom)

Pesticidal mixtures comprising Spinetoram and cyanosulfoximine compounds The invention relates to pesticidal mixtures comprising as active compounds 1) at least one cyanosulfoximine compound I of the formula I wherein X is Cl or CF3 and spinetoram in synergistically effective amounts and optionally 3) one active compound II selected from a group A comprising acteylcholine esterase inhibitors, GABA-gated chloride channel antagonists, sodium channel modulators, nicotinic acetylcholine receptor agonists/antagonists, chloride channel activators, juvenile hormone mimics, compounds affecting the oxidative phosphorylation, inhibitors of the chitin biosynthesis, moulting disruptors, inhibitors of the MET, voltage-dependent sodium channel blockers, inhibitors of the lipid synthesis and other compounds as defined in the description 4) one active fungicidal compounds III selected from azoles, strobilurins, carboxamides, carbamates, heterocyclic and various other compounds as defined in the description. The invention relates further to methods and use of these pesticidal mixtures for combating insects, arachnids or nematodes and harmful fungis in and on plants, and for protecting such plants being infested with pests and also for protecting seeds.

BREUNINGGER DELPHINE; BASETIAANS HENRICUS MARIA MARTINUS; DEYN WOLFGANG VON; PAULINI RALPH; LANGEWALD JUEGEN; HADEN EGON

162

PAN Pesticide Database  

Science.gov (United States)

The Pesticide Action Network (PAN) Pesticide Database is your one-stop location for toxicity and regulatory information for pesticides. This is a comprehensive search enabled database of pesticide chemicals and also trade names. An easy to navigate sidebar takes you through toxicity, uses, registration, company, and distributor. Other links take you to less toxic alternatives, and pesticide tutorial and references.

0002-11-30

163

Plant Epicuticular Lipids: Alteration by Herbicidal Carbamates 1  

Science.gov (United States)

The effect of several carbamates and trichloroacetic acid on the biosynthesis of epicuticular lipids from leaves of pea (Pisum sativum) was tested by chemical and visual methods. The carbamates tested included S-(2,3-dichloroallyl) diisopropylthiocarbamate (diallate), N-(3-chlorophenyl) isopropylcarbamate (chloropropham), S-ethyl dipropylthiocarbamate, and 2-chloroallyl diethyldithiocarbamate. Diallate reduced epicuticular lipids by 50% when the plants were root-treated and by 80% when vapor-treated. These results were supported by scanning electron microscopy and carbon replica techniques with transmission electron microscopy. The ratio of wax lipid components in the diallate-treated plants remained unchanged, with the exception of the primary alcohols, which were reduced. Diallate appears to interfere with the biosynthesis of a precursor to the elongation-decarboxylation pathway of lipid synthesis. N-(3-Chlorophenyl)isopropylcarbamate had no significant effect on total amounts of extractable epicuticular lipids, nor did it alter the structure of the wax formation on the leaves. The scanning electron microscopy micrographs indicated that S-ethyl dipropylthiocarbamate significantly reduced wax formation on pea leaves. 2-Chloroallyl diethyldithiocarbamate altered the structure of the wax formations, but not the total amount of wax (scanning electron microscopy). Trichloroacetic acid had little effect on wax deposition compared to diallate or S-ethyl dipropylthiocarbamate (scanning electron microscopy). The implication of the effect of the carbamates on epicuticular lipids and penetration of subsequent topically applied chemicals is discussed. Images

Still, Gerald G.; Davis, David G.; Zander, G. L.

1970-01-01

164

[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

165

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

UK PubMed Central (United Kingdom)

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 .

Liu C; Qiang ZM; Tian F; Zhang T

2009-01-01

166

Pesticide Warning  

Medline Plus

Full Text Available ... Warning HealthDay May 28, 2013 Related MedlinePlus Pages Parkinson's Disease Pesticides Transcript As Americans focus on beautiful ... higher risk of developing the nervous system disorder, Parkinson's disease. Researchers drilled down, looking at the proximity ...

167

[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

168

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

UK PubMed Central (United Kingdom)

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.

Kobayashi M; Ohtsuka K; Tamura Y; Tomizawa S; Kamijo K; Iwakoshi K; Kageyama Y; Nagayama T; Takano I

2011-01-01

169

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

UK PubMed Central (United Kingdom)

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

Kobayashi M; Ohtsuka K; Tamura Y; Tomizawa S; Kinoshita T; Kamijo K; Iwakoshi K; Sato C; Nagayama T; Takano I

2013-01-01

170

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

Directory of Open Access Journals (Sweden)

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

Maria Isabel Ribeiro Alves; Nelson Roberto Antoniosi Filho

2010-01-01

171

Lubricating oil compositions containing poly(oxyalkylene) aminoether carbamates as dispersing agents  

Energy Technology Data Exchange (ETDEWEB)

This patent describes a lubricating oil composition comprising a major portion of oil of lubrication viscosity, and a minor amount of poly(oxyalkylene) aminohydrocarbyloxyhydrocarbyl carbamate having a molecular weight of about 500 to 10,000; wherein the poly(oxyalkylene) moiety of the carbamate is comprised of oxyalkylene units selected from C/sub 2/-C/sub 5/ oxyalkylene units which a sufficient number are branched-chain oxyalkylene units to render the carbamates soluble in lubricating oil; and the aminohydrocarbyloxyhydrocarbyl moiety of the carbamate being derived from a diaminoether having from 2 to 60 carbon atoms.

Plavac, F.

1988-03-01

172

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

Scientific Electronic Library Online (English)

Full Text Available Abstract in spanish Se optimizó y validó el método de dispersión de matriz en fase sólida (DMFS) para la extracción de plaguicidas organofosforados en hortalizas. Los análisis de plaguicidas se realizaron por cromatografía de gases con un detector fotométrico de flama (FPD) y columna capilar DB-5 la eficiencia de la extraccio. En las hortalizas (chile verde, tomate bola, tomate saladette, cebolla, calabacita y brócoli) se evaluó calculando los porcentajes de recuperación. Para el (more) lo se adicionó una mezcla de los plaguicidas (diazinón, di-systón, metilparatión, malatión, paratión y etión) Se optimizaron las fases de extracción y purificación, donde 0,5 g de sílice como fase de extracción y 2 g de mezcla de carbón-óxido de magnesio-celite (1:2:4) como fase de purificación, produjeron los mayores porcentajes de recuperación de los plaguicidas (61-108%) eluídos con 40 mL de diclorometano, volumen 95% menor al utilizado en el Método Oficial. Los coeficientes de regresión de las curvas de calibración fueron de 0,99 excepto para etión (r = 0,98), los cuales se evaluaron en un intervalo de concentraciones de 50, 100 y 200% de los límites máximos de residuos (LMR). Esta técnica fue aplicada en el análisis de 32 muestras de hortalizas obtenidas de dos centros comerciales locales. Únicamente una muestra de tomate bola presentó niveles de malatión (0,08 µg/g) y paratión (0,06 µg/g), valores por debajo de los LMR. El método de DMFS optimizado y validado en el presente trabajo resultó ser reproducible, exacto y económico-ecológico por su consumo mínimo de disolventes, y pudiera ser utilizado en análisis rutinarios de plaguicidas organofosforados en hortalizas. Abstract in english The objective of this study was the optimization and validation of a method based on matrix solid-phase dispersion (MSPD) for the determination of organophosphorus pesticides in vegetables. This assay was carried out by capillary gas chromatography with Flame Photometric Detection (FPD) and a 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 (more) -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.

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

2006-10-01

173

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.  

Directory of Open Access Journals (Sweden)

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; R. Armenta-Corral; E. Moreno-Villa; L. Gutiérrez-Coronado; P. Grajeda-Cota; C. Orantes-Arenas.

2006-01-01

174

Pesticide composition  

UK PubMed Central (United Kingdom)

The invention relates to a pesticide composition comprising the active components including (A) which is fosthiazate, and (B) which is at least one of abamectin and azadirachtin. The mass ratio of A to B is 100:1-1:50. By combining A and B, the composition has obvious synergistic effect and is used for controlling the pests on such crops as fruit trees, cotton, wheat, rice, rape, vegetables, flowers and the like, especially for controlling nematodes.

HONG ZHANG; MINGZHANG CAO; RULONG YIN; SHENGZHAO LIU; XINJUN WANG; JIAN KONG

175

PESTICIDAL MIXTURES  

UK PubMed Central (United Kingdom)

The invention relates to a pesticidal composition comprising as active ingredient a mixture consisting of one compound (A) as defined in the patent claims and at least one compound (B) as defined in the patent claims, to a process for the preparation of and to the use of such a composition, to a method of controlling pests using such a composition and to plant propagation material treated with such a composition.

ANGST MAX; DUTTON ANA CRISTINA

176

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: 3h (800rpm), addition of 10% of sodium chloride, no addition of methanol as organic modifier, and 15min 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

2013-05-02

177

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

Directory of Open Access Journals (Sweden)

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

M Khodadadi; M.T Samadi; A.R Rahmani

2011-01-01

178

Acetylcholinesterase Based Detection of Residual Pesticides on Cotton  

Directory of Open Access Journals (Sweden)

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

Syed Zameer Ul Hassan; Jiri Militky

2012-01-01

179

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

180

Comparative effect of pesticides on brain acetylcholinesterase in tropical fish.  

Science.gov (United States)

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

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

2012-11-06

 
 
 
 
181

Comparative effect of pesticides on brain acetylcholinesterase in tropical fish.  

UK PubMed Central (United Kingdom)

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

Assis CR; Linhares AG; Oliveira VM; França RC; Carvalho EV; Bezerra RS; de Carvalho LB Jr

2012-12-01

182

ONE-POT PRODUCTION OF CARBAMATES USING SOLID CATALYSTS  

UK PubMed Central (United Kingdom)

The invention relates to the production of carbamates in a single reactor (one-pot) using solid catalysts, involving the reaction between at least one nitro compound, an organic carbonate of formula (OR)(OR)C=O, a gas selected from hydrogen gas and a mixture of gases containing hydrogen and hydrogen precursor compounds, and a catalyst that has at least one metallic oxide and can also contain an element of groups 8, 9, 10 and 11 of the periodical table. The carbonates obtained can be transformed into their corresponding isocyanates.

CORMA CANOS AVELINO; GARCIA GOMEZ HERMENEGILDO; JUAREZ MARIN RAQUEL

183

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

2013-05-13

184

ONE-POT PRODUCTION OF CARBAMATES USING SOLID CATALYSTS  

UK PubMed Central (United Kingdom)

The invention relates to the production of carbamates in a single reactor (one-pot) using solid catalysts, involving the reaction between at least one nitro compound, an organic carbonate of formula (OR)(OR')C-O, a gas selected from hydrogen gas and a mixture of gases containing hydrogen and hydrogen precursor compounds, and a catalyst that has at least one metallic oxide and can also contain an element of groups 8, 9, 10 and 11 of the periodical table. The carbonates obtained can be transformed into their corresponding isocyanates.

CORMA CANOS AVELINO; GARCIA GOMEZ HERMENEGILDO; JUAREZ MARIN RAQUEL

185

ONE-POT PRODUCTION OF CARBAMATES USING SOLID CATALYSTS  

UK PubMed Central (United Kingdom)

The invention relates to the production of carbamates in a single reactor (one-pot) using solid catalysts, involving the reaction between at least one nitro compound, an organic carbonate of formula (OR)(OR')C=O, a gas selected from hydrogen gas and a mixture of gases containing hydrogen and hydrogen precursor compounds, and a catalyst that has at least one metallic oxide and can also contain an element of groups 8, 9, 10 and 11 of the periodical table. The carbonates obtained can be transformed into their corresponding isocyanates.

CORMA CANOS AVELINO; GARCIA GOMEZ HERMENEGILDO; JUAREZ MARIN RAQUEL

186

Brazilian vodkas have undetectable levels of ethyl carbamate  

Scientific Electronic Library Online (English)

Full Text Available 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 t (more) he 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.

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

2013-01-01

187

Synthesis and characterization of monosaccharide-derived carbamates as low-molecular-weight gelators.  

DEFF Research Database (Denmark)

Sugar-based low-molecular-weight gelators are an interesting new class of compounds that are important in supramolecular chemistry and for the preparation of advanced materials. Previously, we synthesized a series of ester and carbamate derivatives of 4,6-O-benzylidene methyl-alpha-D-glucopyranoside and found that monosubstituted alkynyl esters with five to seven carbons and monosubstituted carbamates with saturated five- and seven-carbon chains are good gelators. To understand the structural requirement for the gelation of the carbamate derivatives (O-linked carbamates), a diverse series of analogs, including alkynyl, aryl, and alkyl halide derivatives, were prepared and analyzed. We found that for gelation the O-linked carbamate derivatives have different structural preferences than the ester derivatives. To exhibit gellation, the ester analogs favor alkyl-containing terminal acetylene groups and the carbamoyl derivatives prefer saturated hydrocarbons. Both the esters and the carbamates showed good gelationproperties when they were functionalized with aryl side chains. We also synthesized and screened a new series of carbamates (N-linked carbamates) in which the nitrogen atom of the carbamate group is directly attached to the sugar ring. The N-linked carbamates are good gelators for aqueous DMSO and ethanol solutions, and two of the compounds are also able to form gels in pure water. Optical microscopy and scanning electron microscopy were used to characterize several representative gels. In general, long, narrow, uniform fibrous networks were observed for effective gelators. The structure-gelation correlation obtained here can be used in the design of new sugar-based low-molecular-weight gelators.

Hopkinson, Branden Michael

2009-01-01

188

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

189

Intoxicación por plaguicidas/ Pesticide poisoning  

Scientific Electronic Library Online (English)

Full Text Available 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 (insecticidas, fungicidas, herbicidas, raticidas?) o de su familia química (organoclorados, organofosforados, carbamatos, piretoides, compuestos bipiridílicos, sales inorgánicas?) (more) . 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, raticides?) or by their chemical family (organochlorates, organophosphates, carbamates, pyrethroids, Bipyridilium compounds, inorganic salts?). All of them are biocides, which no (more) rmally 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.

Ferrer, A.

2003-01-01

190

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.  

UK PubMed Central (United Kingdom)

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 < 10% could be attained for all analytes except 17, for which the average recoveries were 70-80%. LOQ ranged within 10-50 ng/g, with < 25% expanded uncertainties, for 155 compounds in grapes and 151 in wine. In the incurred grape and wine samples, the 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.

Dasgupta S; Banerjee K; Dhumal KN; Adsule PG

2011-01-01

191

PESTICIDAL MIXTURES COMPRISING ISOXAZOLINE DERIVATIVES  

UK PubMed Central (United Kingdom)

The present invention provides pesticidal mixtures comprising a component A, a component B and a component C, wherein component A is a compound of formula (I) wherein one of Y1 and Y2 is S, SO or SO2 and the other is CH2 L is a direct bond or methylene A1 and A2 are C-H, or one of A1 and A2 is C-H and the other is N R1 is hydrogen or methyl R2 is chlorodifluoromethyl or trifluoromethyl R3 is 3,5-dibromo-phenyl, 3,5-dichloro-phenyl, 3,4-dichloro-phenyl, or 3,4,5-trichloro-phenyl R4 is methyl R5 is hydrogen or R4 and R5 together form a bridging 1,3-butadiene group component B is a compound selected from Sedaxane, Fludioxonil, Metalaxyl, Mefenoxam, Cyprodinil, Azoxystrobin, Tebuconazole, Difenoconazole, Thiabendazole, Fluopyram, Penflufen, N-[9-(dichloromethylene)-1,2,3,4-tetrahydro-1,4-methanonaphthalen-5-yl]-3-(difluoromethyl)-1-methyl-1H-pyrazole-4-carboxamide and Fuxapyroxad or component B is a compound selected from Tefluthrin, Lambda-cyhalothrin, Abamectin, Spinosad, Spinetoram, Chlorpyrifos, Thiodicarb, Chlorantraniliprole, Cyantraniliprole, Bacillus firmus, Bacillus subtilis, Pasteuria spp. such as P. penetrans and P. nishizawae, Imidacloprid, Thiacloprid, Acetamiprid, Nitenpyram, Dinotefuran, Thiamethoxam, Clothianidin, Nithiazine, Flonicamid, Fipronil, Pyrifluquinazone, Pymetrozine, Sulfoxaflor and Spirotetramat and component C is a compound selected from an insecticide, a fungicide and a nematicide, which insecticide is selected from neonicotinoids, carbamates, diamides, spinosyns, phenylpyrazoles, pyrethroids, Pyrifluquinazone, Pymetrozine, Sulfoxaflor and Spirotetramat which fungicide is selected from Azoxystrobin, Trifloxystrobin, Fluoxastrobin, Cyproconazole, Difenoconazole, Prothioconazole, Tebuconazole, Triticonazole, Fludioxonil, Thiabendazole, Ipconazole, Cyprodinil, Myclobutanil, Metalaxyl, Mefenoxam, Sedaxane, N-[9-(dichloromethylene)-1,2,3,4-tetrahydro-1,4-methanonaphthalen-5-yl]-3-(difluoromethyl)-1-methyl-1H-pyrazole-4-carboxamide, Fluopyram, Penflufen, Fuxapyroxad, Fluopyram, and Penthiopyrad which nematicide is selected from Abamectin, carbamate nematicides organophosphorous nematicides, Captan, Thiophanate-methyl, Thiabendazole, a compound of formula (X), wherein n is 0, 1 or 2 and the thiazole ring may be optionally substituted, Bacillus spp., Streptomyces spp. and Pasteuria spp. Pochonia spp., Metarhizium spp. wherein components B and C are different. The invention also provides methods of using the mixtures in the field of agriculture.

DUTTON ANA CRISTINA; CASSAYRE JEROME YVES; HAAS ULRICH JOHANNES

192

ORGANIC PESTICIDE  

UK PubMed Central (United Kingdom)

This invention pertains to a composition, which is a natural and organic pesticide, specifically with fungicidal and bactericidal action against pathogenic microorganisms in agricultural products such as rootcrops, fruits and vegetables. Examples of such disease-causing microorganisms are Mycosphaerella fijensis causing black Sigatoka disease in Cavendish (banana), Ralstonia solanacearum causing Moko disease in Cavendish (banana), Colletotrichum gloespoiroides and Botryodiplodia theobromae causing anthracnose in crops and fruits, tomato yellow leaf curl virus (TYLCV) in tomatoes, Lasiodiplodia theobromae causing soft rot or fruit rot in crops and fruits, Fusarium oxysporum causing Panama wilt in fruits and crops, and many others. The composition, which is an extract of a fermented concoction of tropical plants, carbon source, protein (nitrogen) source, and a carrier agent, is mainly composed of alpha-hydroxy acids (AHAs) as the active ingredients, with lactic acid as the most dominant AHA, and other natural nutrients, all of which may help strengthen the plant's immune system to fight pathogenic diseases. Since all the major constituents of the composition are generally regarded as safe, this natural pesticide is found to be non-toxic and safe to humans and animals, and environmentally benign.

ZABALLERO GRECILDA SANCHEZ

193

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

194

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; Mezzane Aziza; Meddah Bouchra; Khabbal Youssef; Idrissi Larbi

2009-01-01

195

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.; Trti?-Petrovi? T.; Kumri? K.; Purenovi? M.

2010-01-01

196

Proteome-Wide Reactivity Profiling Identifies Diverse Carbamate Chemotypes Tuned for Serine Hydrolase Inhibition.  

UK PubMed Central (United Kingdom)

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

Chang JW; Cognetta AB 3rd; Niphakis MJ; Cravatt BF

2013-05-01

197

A carbamate-based approach to primaquine prodrugs: antimalarial activity, chemical stability and enzymatic activation.  

UK PubMed Central (United Kingdom)

O-Alkyl and O-aryl carbamate derivatives of the antimalarial drug primaquine were synthesised as potential prodrugs that prevent oxidative deamination to the inactive metabolite carboxyprimaquine. Both O-alkyl and O-aryl carbamates undergo hydrolysis in alkaline and pH 7.4 phosphate buffers to the parent drug, with O-aryl carbamates being ca. 10(6)-10(10) more reactive than their O-alkyl counterparts. In human plasma O-alkyl carbamates were stable, whereas in contrast their O-aryl counterparts rapidly released the corresponding phenol product, with primaquine being released only slowly over longer incubation periods. Activation of the O-aryl carbamates in human plasma appears to be catalysed by butyrylcholinesterase (BuChE), which leads to carbamoylation of the catalytic serine of the enzyme followed by subsequent slow enzyme reactivation and release of parent drug. Most of the O-aryl and O-alkyl carbamates are activated in rat liver homogenates with half-lives ranging from 9 to 15 h, while the 4-nitrophenyl carbamate was hydrolysed too rapidly to determine an accurate rate constant. Antimalarial activity was studied using a model consisting of Plasmodium berghei, Balb C mice and Anopheles stephensi mosquitoes. When compared to controls, ethyl and n-hexyl carbamates were able to significantly reduce the percentage of infected mosquitos as well as the mean number of oocysts per infected mosquito, thus indicating that O-alkyl carbamates of primaquine have the potential to be developed as transmission-blocking antimalarial agents.

Mata G; do Rosário VE; Iley J; Constantino L; Moreira R

2012-01-01

198

Evaluation of Four Bio fertilizers for Bioremediation of Pesticide contaminated Soil  

International Nuclear Information System (INIS)

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

1999-01-01

199

Postcolumn photolysis of pesticides for fluorometric determination by high-performance liquid chromatography  

Energy Technology Data Exchange (ETDEWEB)

A high-performance liquid chromatography postcolumn reaction detector that employs UV photolysis with an optional reaction by using o-phthalaldehyde-2-mercaptoethanol (OPA-MERC) followed by fluorescence detection was found to be useful for several classes of pesticides. In the presence of the OPA-MERC reagent, most carbamates, carbamoyl oximes, carbamothioic acids, and substituted ureas gave a sensitive response while the response of dithiocarbamates, phenylamides, and phenylcarbamates varied. The response of most of the pesticides tested was significantly affected by the solvent used. Method detection limits for aldicarb sulfoxide, aldicarb, propoxur, thiram, and neburon in ground water were 2.5, 2.3, 3.3, 3.8, and 2.0 ..mu..g/L, respectively. In the absence of OPA-MERC reagent, several of the substituted aromatic compounds also gave strong fluorescence after photolysis. This detector is applicable to a broad range of nitrogenous pesticides.

Miles, C.J.; Moye, H.A.

1988-02-01

200

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

UK PubMed Central (United Kingdom)

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

Schulte-Oehlmann U; Oehlmann J; Keil F

2011-01-01

 
 
 
 
201

Estimating pesticide runoff in small streams.  

Science.gov (United States)

Surface runoff is one of the most important pathways for pesticides to enter surface waters. Mathematical models are employed to characterize its spatio-temporal variability within landscapes, but they must be simple owing to the limited availability and low resolution of data at this scale. This study aimed to validate a simplified spatially-explicit model that is developed for the regional scale to calculate the runoff potential (RP). The RP is a generic indicator of the magnitude of pesticide inputs into streams via runoff. The underlying runoff model considers key environmental factors affecting runoff (precipitation, topography, land use, and soil characteristics), but predicts losses of a generic substance instead of any one pesticide. We predicted and evaluated RP for 20 small streams. RP input data were extracted from governmental databases. Pesticide measurements from a triennial study were used for validation. Measured pesticide concentrations were standardized by the applied mass per catchment and the water solubility of the relevant compounds. The maximum standardized concentration per site and year (runoff loss, R(Loss)) provided a generalized measure of observed pesticide inputs into the streams. Average RP explained 75% (p<0.001) of the variance in R(Loss). Our results imply that the generic indicator can give an adequate estimate of runoff inputs into small streams, wherever data of similar resolution are available. Therefore, we suggest RP for a first quick and cost-effective location of potential runoff hot spots at the landscape level. PMID:17395242

Schriever, Carola A; von der Ohe, Peter C; Liess, Matthias

2007-03-28

202

Mixed anhydrides: key intermediates in carbamates forming processes of industrial interest.  

Science.gov (United States)

Mixed anhydrides of carbonic acid with phosphonic or carbamic acid, are mimic of relevant biological systems, and behave as key intermediates in trans-esterification processes that afford carbamates of industrial interest. They are formed in the phosphonic acids mediated or direct transesterification reaction of organic carbonates with amines to afford carbamates and have been isolated and characterised in the solid state and solution. Their conversion into the products has been demonstrated to occur with high regioselectivity. The application of such intermediates in some synthetic processes is discussed. PMID:11855716

Aresta, Michele; Dibenedetto, Angela

2002-02-01

203

Mixed anhydrides: key intermediates in carbamates forming processes of industrial interest.  

UK PubMed Central (United Kingdom)

Mixed anhydrides of carbonic acid with phosphonic or carbamic acid, are mimic of relevant biological systems, and behave as key intermediates in trans-esterification processes that afford carbamates of industrial interest. They are formed in the phosphonic acids mediated or direct transesterification reaction of organic carbonates with amines to afford carbamates and have been isolated and characterised in the solid state and solution. Their conversion into the products has been demonstrated to occur with high regioselectivity. The application of such intermediates in some synthetic processes is discussed.

Aresta M; Dibenedetto A

2002-02-01

204

Pesticidal compositions  

UK PubMed Central (United Kingdom)

A pesticidal composition comprising (i) one or more essential oils selected from tagetes oil or a thymol containining oil such as thyme oil, or a mixture thereof, or components thereof which have insect repellent or deterrent properties, which have insect repellent or deterrent properties, wherein the total amount of such oil present does not exceed 10%w/w (ii) an agriculturally acceptable carrier oil and (iii) an emulsifier. In particular, the composition further comprises a compound, which remediates symptoms of viral infection, such as wintergreen oil. Use Of Compositions of this type in agriculture controls pests whilst reducing the amount of essential oil required. Furthermore, a combined effect of controlling insects, preventing reinfestation and viral symptom remediation is obtainable.

MARKS DAVID

205

PESTICIDAL COMPOSITIONS  

UK PubMed Central (United Kingdom)

A pesticidal composition comprising (i) one or more essential oils selected from tagetes oil or a thymol containining oil such as thyme oil, or a mixture thereof, or components thereof which have insect repellent or deterrent properties, which have insect repellent or deterrent properties, wherein the total amount of such oil present does not exceed 10%w/w (ii) an agriculturally acceptable carrier oil and (iii) an emulsifier. In particular, the composition further comprises a compound, which remediates symptoms of viral infection, such as wintergreen oil. Use Of Compositions of this type in agriculture controls pests whilst reducing the amount of essential oil required. Furthermore, a combined effect of controlling insects, preventing reinfestation and viral symptom remediation is obtainable. TM KIPO & WIPO 2007

MARKS DAVID

206

Pesticidal compositions  

UK PubMed Central (United Kingdom)

A pesticidal composition comprising (i) one or more essential oils selected from tagetes oil or a thymol containining oil such as thyme oil, or a mixture thereof, or components thereof which have insect repellent or deterrent properties, which have insect repellent or deterrent properties, wherein the total amount of such oil present does not exceed 10 % w/w; (ii) an agriculturally acceptable carrier oil and (iii) an emulsifier. In particular, the composition further comprises a compound, which remediates symptoms of viral infection, such as wintergreen oil. Use Of Compositions of this type in agriculture controls pests whilst reducing the amount of essential oil required. Furthermore, a combined effect of controlling insects, preventing reinfestation and viral symptom remediation is obtainable.

MARKS DAVID

207

PESTICIDAL COMPOSITIONS  

UK PubMed Central (United Kingdom)

A pesticidal composition comprising (i) one or more essential oils selected from tagetes oil or a thymol containining oil such as thyme oil, or a mixture thereof, or components thereof which have insect repellent or deterrent properties, which have insect repellent or deterrent properties, wherein the total amount of such oil present does not exceed 10%w/w; (ii) an agriculturally acceptable carrier oil and (iii) an emulsifier. In particular, the composition further comprises a compound, which remediates symptoms of viral infection, such as wintergreen oil. Use Of Compositions of this type in agriculture controls pests whilst reducing the amount of essential oil required. Furthermore, a combined effect of controlling insects, preventing reinfestation and viral symptom remediation is obtainable.

MARKS David

208

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

UK PubMed Central (United Kingdom)

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.

Kachuri L; Demers PA; Blair A; Spinelli JJ; Pahwa M; McLaughlin JR; Pahwa P; Dosman JA; Harris SA

2013-10-01

209

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

UK PubMed Central (United Kingdom)

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

Kubrak OI; Atamaniuk TM; Husak VV; Drohomyretska IZ; Storey JM; Storey KB; Lushchak VI

2012-11-01

210

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

Science.gov (United States)

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

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

2012-09-07

211

Determination of ethyl carbamate in cachaca produced from copper stills by HPLC.  

UK PubMed Central (United Kingdom)

Ethyl carbamate (EC) is a common substance in fermented foods and drinks, and its quantification is important because of its carcinogenic nature and its usually presence in alcoholic beverages. The present work involved the development and validation of an analytical method for the evaluation of EC in cachaça by HPLC-FLD after previous derivatization with xanthydrol. The method presented a mean recovery of 94.88%, an intra-day precision of 4.19% (30.0 ?gL(-1)) and 3.32% (75.0 ?gL(-1)), a coefficient of determination (r(2)) equal to 0.9985, and limits of detection and quantification equal to 6.39 and 21.32 ?gL(-1), respectively. The results show that the analytical method is accurate, reproducible and linear over the concentration range from 5.0 to 160 ?g of EC per litre. The method was applied to the analysis of EC in cachaça, the analyses being rapid and efficient.

de Resende Machado AM; Cardoso Md; Saczk AA; dos Anjos JP; Zacaroni LM; Dórea HS; Nelson DL

2013-06-01

212

Ultrasound-assisted emulsification-microextraction for the sensitive determination of ethyl carbamate in alcoholic beverages.  

UK PubMed Central (United Kingdom)

A method based on ultrasound-assisted emulsification-microextraction (USAEME) was proposed in this contribution for the determination of ethyl carbamate (EC) in alcoholic beverages using gas chromatography coupled to triple quadrupole mass spectrometry. To achieve the determination of EC in alcoholic beverages, the influences on the extraction efficiency of type and volume of extraction solvent, temperature, ionic strength, alcohol content, and extraction time were studied, once the extraction solvent had been selected. The optimized conditions were 200.0 ?L of chloroform at 30 °C during 5 min with 15 % (m/v) sodium chloride addition. The detection limit, relative standard deviations, linear range, and recoveries under the optimized conditions were 0.03 ?g L(-1), 4.2-6.1 %, 0.1-50.0 ?g L(-1), and 80.5-87.9 %, respectively. Moreover, the feasibility of the present method was also validated by real samples. To the best of our knowledge, this is the first time that USAEME has been applied to determine a strongly hydrophilic compound in alcoholic beverages.

Liao QG; Li WH; Luo LG

2013-08-01

213

Chiral rhodium(II,II) dimers catalyzed enantioselective intramolecular aziridination of sulfonamides and carbamates  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The asymmetric intramolecular aziridination of unsaturated sulfonamides and carbamates catalyzed by chiral dirhodium(II,II) complexes were achieved in good yields (up to 95%) and enantioselectivity (up to 76% e.e.). © 2003 Elsevier Ltd. All rights reserved.

Liang, JL; Yuan, SX; Chan, PWH; Che, CM

214

A novel, unusually efficacious duocarmycin carbamate prodrug that releases no residual byproduct.  

UK PubMed Central (United Kingdom)

A unique heterocyclic carbamate prodrug of seco-CBI-indole(2) that releases no residual byproduct is reported as a new member of a class of hydrolyzable prodrugs of the duocarmycin and CC-1065 family of natural products. The prodrug was designed to be activated by hydrolysis of a carbamate releasing the free drug without the cleavage release of a traceable extraneous group. Unlike prior carbamate prodrugs examined that are rapidly cleaved in vivo, the cyclic carbamate was found to be exceptionally stable to hydrolysis under both chemical and biological conditions providing a slow, sustained release of the exceptionally potent free drug. An in vivo evaluation of the prodrug found that its efficacy exceeded that of the parent drug, that its therapeutic window of efficacy versus toxicity is much larger than the parent drug, and that its slow free drug release permitted the safe and efficacious use of doses 150-fold higher than the parent compound.

Wolfe AL; Duncan KK; Parelkar NK; Weir SJ; Vielhauer GA; Boger DL

2012-06-01

215

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

Energy Technology Data Exchange (ETDEWEB)

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

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

1990-08-01

216

Chemoselective alkynylation of N-sulfonylamides versus amides and carbamates--synthesis of tetrahydropyrazines.  

UK PubMed Central (United Kingdom)

The chemoselective alkynylation of N-sulfonylamides versus amides and carbamates using TMS-EBX as an alkynylating agent leads to the formation of non-symmetrical tetrahydropyrazines from orthogonally protected diamines.

Aubineau T; Cossy J

2013-04-01

217

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 ... 800-CLEANUP. State and local laws regarding pesticide disposal may be stricter than the Federal requirements on ...

218

Pesticide Fact Sheet: Flufenacet.  

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

219

Pesticide Monitoring Program 2008  

Science.gov (United States)

... FLUQUINCONAZOLE *. FLUROXYPYR +. FLUSILAZOLE *. FLUTOLANIL *. FLUVALINATE *. FOE 5043 (FLUFENACET). FOLPET *. FONOFOS. ... More results from www.fda.gov/food/foodborneillnesscontaminants/pesticides

220

N-Methylimidazole-catalyzed synthesis of carbamates from hydroxamic acids via the Lossen rearrangement.  

UK PubMed Central (United Kingdom)

An efficient, one-pot, N-methylimidazole (NMI) accelerated synthesis of aromatic and aliphatic carbamates via the Lossen rearrangement is reported. NMI is a catalyst for the conversion of isocyanate intermediates to the carbamates. Moreover, the utility of arylsulfonyl chloride in combination with NMI minimizes the formation of often-observed hydroxamate-isocyanate dimers during the sequence. Under the present conditions, lowering of temperatures is also possible, enabling a mild protocol.

Yoganathan S; Miller SJ

2013-02-01

 
 
 
 
221

Lanthanum(III) isopropoxide catalyzed chemoselective transesterification of dimethyl carbonate and methyl carbamates.  

UK PubMed Central (United Kingdom)

A practical transesterification of less reactive dimethyl carbonate and much less reactive methyl carbamates with primary (1°), secondary (2°), and tertiary (3°) alcohols was established with the use of a lanthanum(III) complex, which was prepared in situ from lanthanum(III) isopropoxide (3 mol %) and 2-(2-methoxyethoxy)ethanol (6 mol %). In particular, corresponding carbonates and carbamates obtained were of synthetic utility from the viewpoint of the selective protection and/or deprotection of 1°-, 2°-, and 3°-alcohols.

Hatano M; Kamiya S; Moriyama K; Ishihara K

2011-02-01

222

Effects of carbamates on whole blood cholinesterase activity: chemical protection against soman.  

UK PubMed Central (United Kingdom)

The toxicity (LD50) of several carbamates, all reversible inhibitors of cholinesterase (ChE), were determined in male rabbits. These include isopropyl methylphenyl carbamate (IMPC), pyridostigmine, neostigmine, benzpyrinium and physostigmine. When 1/9 of the LD50 of the above carbamates was individually combined with atropine (A) and benactyzine (B), mecamylamine (M) or chloropromazine (CPZ) and administered to rabbits in a pretreatment regimen, most animals could be protected from a 10 LD50 challenge of Soman. If CPZ, M or B was omitted from this regimen, no rabbits survived this challenge of Soman. The protection afforded against Soman was found to be related to reversible inhibition of ChE by the carbamates; reversible ChE inhibition varied with the route of injection and with the physical properties of the carbamate. Oral administration of pyridostigmine, a quaternary carbamate, provided protection for 24 hours. When the pretreatment included four components (pyridostigmine, A, M and B), the LD50 of Soman was raised 30.8 times in rabbits.

Heyl WC; Harris LW; Stitcher DL

1980-01-01

223

Effects of carbamates on whole blood cholinesterase activity: chemical protection against soman.  

Science.gov (United States)

The toxicity (LD50) of several carbamates, all reversible inhibitors of cholinesterase (ChE), were determined in male rabbits. These include isopropyl methylphenyl carbamate (IMPC), pyridostigmine, neostigmine, benzpyrinium and physostigmine. When 1/9 of the LD50 of the above carbamates was individually combined with atropine (A) and benactyzine (B), mecamylamine (M) or chloropromazine (CPZ) and administered to rabbits in a pretreatment regimen, most animals could be protected from a 10 LD50 challenge of Soman. If CPZ, M or B was omitted from this regimen, no rabbits survived this challenge of Soman. The protection afforded against Soman was found to be related to reversible inhibition of ChE by the carbamates; reversible ChE inhibition varied with the route of injection and with the physical properties of the carbamate. Oral administration of pyridostigmine, a quaternary carbamate, provided protection for 24 hours. When the pretreatment included four components (pyridostigmine, A, M and B), the LD50 of Soman was raised 30.8 times in rabbits. PMID:7449657

Heyl, W C; Harris, L W; Stitcher, D L

1980-01-01

224

The contribution of azodicarbonamide to ethyl carbamate formation in bread and beer.  

UK PubMed Central (United Kingdom)

Data on ethyl carbamate concentrations in beers purchased and analysed between 1988 and 1990 are presented. The concentrations in draught beers were uniformly below the detection limit of 1 microgram/l. Canned beers contained rather more ethyl carbamate (up to 2.5 micrograms/l) which is considered to be due to their longer shelf-life and higher alcohol content (in some cases). Bottled beers contained even higher amounts of ethyl carbamate (up to 14.7 micrograms/l) and this was considered to be due to the use of azodicarbonamide as a blowing agent in the beer bottle cap liners. It is understood that modifications to the liner have led to reduced concentrations in bottled beers produced more recently. A survey of bread samples and related cereal products such as rusks, French toasts and pitta bread indicated typical ethyl carbamate concentrations between < 0.4 and 4.5 micrograms/kg. Toasting bread led to increases of between three- and eight-fold in ethyl carbamate concentrations ranging from 3.5 to 33.8 micrograms/kg on a wet weight basis. Analysis of the data indicated that commercial bread samples which indicated the use of azodicarbonamide as a flour improver showed statistically significant increases in ethyl carbamate concentrations. The mean increase for treated bread over untreated bread was 66%. When these breads were toasted, the mean increase for treated toast over untreated toast was 56%.

Dennis MJ; Massey RC; Ginn R; Willetts P; Crews C; Parker I

1997-01-01

225

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2010-10-15

226

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.

2010-01-01

227

Hypothyroidism and Pesticide Use Among Male Private Pesticide Applicators in the Agricultural Health Study.  

UK PubMed Central (United Kingdom)

OBJECTIVE:: Evaluate the association between thyroid disease and use of insecticides, herbicides, and fumigants/fungicides in male applicators in the Agricultural Health Study. METHODS:: We examined the association between use of 50 specific pesticides and self-reported hypothyroidism, hyperthyroidism, and "other" thyroid disease among 22,246 male pesticide applicators. RESULTS:: There was increased odds of hypothyroidism with ever use of the herbicides 2,4-D (2,4-dichlorophenoxyacetic acid), 2,4,5-T (2,4,5-trichlorophenoxyacetic acid), 2,4,5-TP (2,4,5-trichlorophenoxy-propionic acid), alachlor, dicamba, and petroleum oil. Hypothyroidism was also associated with ever use of eight insecticides: organochlorines chlordane, dichlorodiphenyltrichloroethane (DDT), heptachlor, lindane, and toxaphene; organophosphates diazinon and malathion; and the carbamate carbofuran. Exposure-response analysis showed increasing odds with increasing level of exposure for the herbicides alachlor and 2,4-D and the insecticides aldrin, chlordane, DDT, lindane, and parathion. CONCLUSION:: There is an association between hypothyroidism and specific herbicides and insecticides in male applicators, similar to previous results for spouses.

Goldner WS; Sandler DP; Yu F; Shostrom V; Hoppin JA; Kamel F; Levan TD

2013-09-01

228

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

UK PubMed Central (United Kingdom)

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

Wan MT

2013-01-01

229

DETERMINATION OF DITHIOCARBAMATE PESTICIDES IN WASTEWATERS  

Science.gov (United States)

A method was modified and validated for the determination of dithiocarbamate pesticides in wastewaters. The developed method consists of sample pH adjustment to pH 12.2; removal of indigenous CS2 by purging in a vortex evaporator; acidification of the sample to hydrolyze dithioca...

230

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

2007-08-08

231

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

UK PubMed Central (United Kingdom)

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

Silva KC; Assis CR; Oliveira VM; Carvalho LB Jr; Bezerra RS

2013-01-01

232

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

Science.gov (United States)

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

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

2012-11-09

233

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.

2009-01-01

234

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

235

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

236

Pesticide exposure among pregnant women in Jerusalem, Israel: results of a pilot study.  

UK PubMed Central (United Kingdom)

BACKGROUND: Pesticides have been shown to disrupt neurodevelopment in laboratory animals and in human populations. To date, there have been no studies on exposure to pesticides in pregnant women in Israel, despite reports of widespread exposure in other populations of pregnant women and the importance of evaluating exposure in this susceptible sub-population. METHODS: We measured urinary concentrations of organophosphorus (OP) insecticide metabolites and plasma concentrations of OP and other pesticides in 20 pregnant women, recruited in Jerusalem, Israel in 2006, and collected questionnaire data on demographic factors and consumer habits from these women. We compared geometric mean concentrations in subgroups using the Mann-Whitney U-test for independent samples. We compared creatinine-adjusted OP pesticide metabolite concentrations, as well as plasma pesticide concentrations, with other populations of pregnant women. RESULTS: Creatinine-adjusted total dimethyl (DM) metabolite concentrations were between 4 and 6 times higher in this population compared to other populations of pregnant women in the United States while total diethyl (DE) metabolite concentrations were lower. Dimethylphosphate (DMP) was detected in 74% of the urine samples whereas dimethylthiophosphate (DMTP) was detected in 90% of the urine samples. The carbamate bendiocarb was detected in 89% of the plasma samples, while the OP insecticide chlorpyrifos was detected in 42% of the samples. Mean plasma concentrations of bendiocarb and chlorpyrifos in our sample were 4.4 and 3.9 times higher, respectively, than that of an urban minority cohort from New York City. Twelve women (63%) reported using some form of household pest control during their pregnancy and five (26%) reported using household pest control during the past month. Women with a graduate degree had significantly higher geometric mean concentrations of total urinary DM metabolite concentrations compared to other women (P=0.006). Finally, one woman in the study had exceptionally high concentrations of DMP, DMTP, DMDTP compared to the other women in the study, despite reporting no current occupational exposure to OP pesticides and no other significant exposure sources. CONCLUSIONS: Pregnant women in the Jerusalem area are exposed to OP pesticides and to the carbamate pesticide bendiocarb. It is unclear why total DM metabolites concentrations were much higher in this population compared to other populations of pregnant women in the United States and Netherlands. Finally, the finding of very high DM metabolite concentrations in one woman who reported being moved from her regular laboratory work to administrative work upon becoming pregnant, raises questions about the adequacy of measures to protect pregnant women from pesticide exposures during pregnancy.

Berman T; Hochner-Celnikier D; Barr DB; Needham LL; Amitai Y; Wormser U; Richter E

2011-01-01

237

Theoretical prediction of the photoinduced chemiluminescence of pesticides.  

Science.gov (United States)

Although it is relatively easy to find chemiluminescent (CL) molecules working on the field of direct liquid phase (especially employing strong oxidants), the molecules found as chemiluminescent are normally very weak CL compounds for developing suitable analytical CL-procedures. Therefore, it is mandatory to develop new strategies to enhance in a simple way the native chemiluminescence of such a compounds, and even to increase the number of compounds to be determined by direct chemiluminescence. Photoinduced chemiluminescence (Ph-CL) results in a simple and easily on-line accessible strategy to solve these disadvantages. In the present paper, molecular connectivity, a topological method which allows an unique mathematical characterization of molecular structures by the so-named topological descriptors and their correlation with physical, chemical and biological properties of molecules was applied to predict the Ph-CL in liquid phase. Molecular connectivity calculations and discriminant analysis was applied to 72 pesticides for which either a Ph-CL or non Ph-CL behaviour was observed in an experimental screening. The screening test is based on the on-line photodegradation of pesticides by using an automated multicommutation based flow asssembly provided with a photoreactor consisting of 150 cm x 0.8mm PTFE tubing helically coiled around a 20 W low-pressure mercury lamp. Photodegraded pesticides are detected by direct chemiluminescence of the resulting photo-fragments and their subsequent reaction with potassium permanganate in sulfuric acid medium as oxidant. The screening comprised pesticides with different molecular structures and relevant members of the most important families of pesticides were tested (oxime carbamates, sulfonylcarbamates, thiocarbamates, 1,3,5-triazines, organophosphorous, hydroxybenzonitrile, sulfonylureas, phosphonic acid derivatives, imidazolinones, carboxamides, aryloxyalkanoic acids, 1,2,4-triazinones, etc.). The theoretical predictions agree with the empirical results obtained by means of the screening test performed in the multicommutation flow-assembly. PMID:19071628

Ricart, I Sahuquillo; Antón-Fos, G M; Duart, M J; Mateo, J V García; Zamora, L Lahuerta; Calatayud, J Martínez

2006-12-08

238

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

Scientific Electronic Library Online (English)

Full Text Available Abstract in english A multiresidue method using HPLC/DAD for the determination of fourteen pesticides in water based on SPE, using SDVB (styrene divynilbenzene copolymer) as adsorbent was validated. Recoveries from 61 to 120%, relative standard deviation between 2 and 15% and detection limits from 0.07 to 0.75 µg L-1 were obtained. It was applied to 66 surface water samples collected in a degraded area at the headwaters of São Lourenço river, Mato Grosso, Brazil. Eight pesticides were det (more) ected 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.

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

2013-01-01

239

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

Directory of Open Access Journals (Sweden)

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

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

2013-01-01

240

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

Scientific Electronic Library Online (English)

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

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

2009-03-01

 
 
 
 
241

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

Directory of Open Access Journals (Sweden)

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

Karl Schosinsky; Eugenia María Quintana Guzmán; Clements Ruepert

2009-01-01

242

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

Science.gov (United States)

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

Yenisoy-Karaka?, Serpil; Gaga, Eftade O

2013-04-27

243

[Survey and analysis of ethyl carbamate in commercial fermented foods in Hangzhou in 2010].  

UK PubMed Central (United Kingdom)

OBJECTIVE: To observe the ethyl carbamate concentrations in different commercial fermented foods in Hangzhou in 2010. METHODS: In 2010, 237 commercial fermented food samples of eight categories, including yellow wine, white spirit, wine, beer, cooking wine, sauce, vinegar and fermented bean curd, were purchased from 3 different size markets respectively in Hangzhou. The ethyl carbamate was measured by gas chromatography-mass spectrometry in selection ion mode, after the samples were coupled with D5-ethyl carbamate, and purified by diatomite solid phase extraction column. RESULTS: The results showed that ethyl carbamate was detected in all samples analyzed (100%) with the range from 2.0 µg/kg to 515.0 µg/kg. The ethyl carbamate average (median) levels in 8 food categories were descending with fermented red bean curd (182.2 µg/kg (161.2 µg/kg)), yellow wine (159.6 µg/kg (121.0 µg/kg)), cooking wine (86.8 µg/kg (95.6 µg/kg)), white spirit (72.0 µg/kg (60.5 µg/kg)), soy sauce (47.2 µg/kg (40.7µg/kg)), vinegar (26.7 µg/kg (31.8 µg/kg)), wine (15.7 µg/kg (16.8 µg/kg)) and beer (2.2 µg/kg (2.3 µg/kg)). CONCLUSION: The ethyl carbamate was detected in all fermented foods in Hangzhou in 2010, and the levels of ethyl carbamate in red bean curd and yellow wine were higher than others.

Wu PG; Yang DJ; Shen XH; Wang LY; Pan XD; Zhang J; Zhao YX; Tan Y

2011-07-01

244

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

UK PubMed Central (United Kingdom)

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

Ochoa V; Riva C; Faria M; Barata C

2013-01-01

245

Ethyl carbamate levels resulting from azodicarbonamide use in bread.  

UK PubMed Central (United Kingdom)

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.

Cañas BJ; Diachenko GW; Nyman PJ

1997-01-01

246

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

247

Carbamate insecticide methomyl confers cytotoxicity through DNA damage induction.  

UK PubMed Central (United Kingdom)

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

Guanggang X; Diqiu L; Jianzhong Y; Jingmin G; Huifeng Z; Mingan S; Liming T

2013-03-01

248

Biological monitoring of chlorinated pesticides among exposed workers of mango orchards: A case study in tropical climate  

Energy Technology Data Exchange (ETDEWEB)

Organochlorine, organophosphorus and carbamate compounds are widely used pesticides in India for controlling disease carrying vectors and agricultural pests. Organochlorine compounds being persistent and lipophilic in nature, accumulate in the human body through food chain and environmental exposure. Accumulation of DDT, BHC and endosulfan has been implicated in the pathogenesis of cardiovascular disorders, hypertension and other health related problems. Earlier, the authors have observed respiratory impairment (36.5%) among workers engaged in spraying of organochlorine pesticides on mango trees at Malihabad. In the present investigation, the levels of chlorinated present investigation, the levels of chlorinated pesticides among exposed workers have been monitored to study the distribution pattern in blood and their excretion in urine of human subjects.

Chandra, H.; Pangtey, B.S.; Modak, D.P.; Singh, K.P.; Gupta, B.N.; Bharti, R.S.; Srivastava, S.P. (Industrial Toxicology Research Centre, Lucknow (India))

1992-02-01

249

Pesticide Residue Monitoring Program 1998  

Science.gov (United States)

Pesticide Program Residue Monitoring 1998: annual report summarizing the results of the Food and Drug Administration's (FDA) pesticide residue ... More results from www.fda.gov/food/foodborneillnesscontaminants/pesticides

250

Consumer Products Treated with Pesticides  

Science.gov (United States)

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

251

The effect of azodicarbonamide concentrations on ethyl carbamate concentrations in bread and toast.  

Science.gov (United States)

A series of baking experiments have been undertaken in order to test the proposition that the use of the flour improver azodicarbonamide influences ethyl carbamate concentrations in baked bread. Samples were prepared in a laboratory and contained 0, 20 and 45 mg azodicarbonamide/kg; 20 mg/kg reflecting normal commercial usage and 45 mg/kg the UK statutory limit. Samples incorporating 0 and 20 mg/kg of the additive were also prepared in a commercial bakery. Toast made from these breads was examined since it is known that toasting can lead to increased ethyl carbamate concentrations. Statistical analysis of the data indicated that, at 45 mg/kg, azodicarbonamide led to significant increases in ethyl carbamate concentrations in both bread and the toasts made from it. At 20 mg/kg some small increases in ethyl carbamate were seen for bread and this approached statistical significance for those samples made in the commercial plant. When these breads were toasted an increase in ethyl carbamate was observed but this was not attributable to the use of azodicarbonamide. PMID:9059588

Dennis, M J; Massey, R C; Ginn, R; Parker, I; Crews, C; Zimmerli, B; Zoller, O; Rhyn, P; Osborne, B

1997-01-01

252

The effect of azodicarbonamide concentrations on ethyl carbamate concentrations in bread and toast.  

UK PubMed Central (United Kingdom)

A series of baking experiments have been undertaken in order to test the proposition that the use of the flour improver azodicarbonamide influences ethyl carbamate concentrations in baked bread. Samples were prepared in a laboratory and contained 0, 20 and 45 mg azodicarbonamide/kg; 20 mg/kg reflecting normal commercial usage and 45 mg/kg the UK statutory limit. Samples incorporating 0 and 20 mg/kg of the additive were also prepared in a commercial bakery. Toast made from these breads was examined since it is known that toasting can lead to increased ethyl carbamate concentrations. Statistical analysis of the data indicated that, at 45 mg/kg, azodicarbonamide led to significant increases in ethyl carbamate concentrations in both bread and the toasts made from it. At 20 mg/kg some small increases in ethyl carbamate were seen for bread and this approached statistical significance for those samples made in the commercial plant. When these breads were toasted an increase in ethyl carbamate was observed but this was not attributable to the use of azodicarbonamide.

Dennis MJ; Massey RC; Ginn R; Parker I; Crews C; Zimmerli B; Zoller O; Rhyn P; Osborne B

1997-01-01

253

The contribution of azodicarbonamide to ethyl carbamate formation in bread and beer.  

Science.gov (United States)

Data on ethyl carbamate concentrations in beers purchased and analysed between 1988 and 1990 are presented. The concentrations in draught beers were uniformly below the detection limit of 1 microgram/l. Canned beers contained rather more ethyl carbamate (up to 2.5 micrograms/l) which is considered to be due to their longer shelf-life and higher alcohol content (in some cases). Bottled beers contained even higher amounts of ethyl carbamate (up to 14.7 micrograms/l) and this was considered to be due to the use of azodicarbonamide as a blowing agent in the beer bottle cap liners. It is understood that modifications to the liner have led to reduced concentrations in bottled beers produced more recently. A survey of bread samples and related cereal products such as rusks, French toasts and pitta bread indicated typical ethyl carbamate concentrations between azodicarbonamide as a flour improver showed statistically significant increases in ethyl carbamate concentrations. The mean increase for treated bread over untreated bread was 66%. When these breads were toasted, the mean increase for treated toast over untreated toast was 56%. PMID:9059589

Dennis, M J; Massey, R C; Ginn, R; Willetts, P; Crews, C; Parker, I

1997-01-01

254

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

Directory of Open Access Journals (Sweden)

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

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

2011-01-01

255

Pesticides and oncogenic modulation.  

UK PubMed Central (United Kingdom)

Pesticides constitute a diverse class of chemicals used for the protection of agricultural products. Several lines of evidence demonstrate that organochlorine and organophosphate pesticides can cause malignant transformation of cells in in vitro and in vivo models. In the current minireview a comprehensive summary of recent in vitro findings is presented along with data reported from human population studies, regarding the impact of pesticide exposure on activation or dysregulation of oncogenes and tumor suppressor genes. Substantial mechanistic work suggests that pesticides are capable of inducing mutations in oncogenes and increase their transcriptional expression in vitro, whereas human population studies indicate associations between pesticide exposure levels and mutation occurrence in cancer-related genes. Further work is required to fully explore the exact mechanisms by which pesticide exposure affects the integrity and normal function of oncogenes and tumor suppressor genes in human populations.

Vakonaki E; Androutsopoulos VP; Liesivuori J; Tsatsakis AM; Spandidos DA

2013-05-01

256

Pesticide exposure in children.  

UK PubMed Central (United Kingdom)

This statement presents the position of the American Academy of Pediatrics on pesticides. Pesticides are a collective term for chemicals intended to kill unwanted insects, plants, molds, and rodents. Children encounter pesticides daily and have unique susceptibilities to their potential toxicity. Acute poisoning risks are clear, and understanding of chronic health implications from both acute and chronic exposure are emerging. Epidemiologic evidence demonstrates associations between early life exposure to pesticides and pediatric cancers, decreased cognitive function, and behavioral problems. Related animal toxicology studies provide supportive biological plausibility for these findings. Recognizing and reducing problematic exposures will require attention to current inadequacies in medical training, public health tracking, and regulatory action on pesticides. Ongoing research describing toxicologic vulnerabilities and exposure factors across the life span are needed to inform regulatory needs and appropriate interventions. Policies that promote integrated pest management, comprehensive pesticide labeling, and marketing practices that incorporate child health considerations will enhance safe use.

2012-12-01

257

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

UK PubMed Central (United Kingdom)

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

Toan PV; Sebesvari Z; Bläsing M; Rosendahl I; Renaud FG

2013-05-01

258

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

Science.gov (United States)

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

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

2013-03-15

259

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

UK PubMed Central (United Kingdom)

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.

Azizullah A; Richter P; Häder DP

2011-08-01

260

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

2011-05-12

 
 
 
 
261

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

UK PubMed Central (United Kingdom)

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.

Pahwa P; Karunanayake CP; Dosman JA; Spinelli JJ; McDuffie HH; McLaughlin JR

2012-01-01

262

Liquid pesticide composition  

UK PubMed Central (United Kingdom)

The invention concerns a liquid emulsifiable pesticide concentrate comprising a pesticidally active ingredient and 10-50 wt.-%, based on the concentrate, of a polyoxyethylene alkyl ether having an HLB value of 6-13.5. Preferably, the pesticidally active ingredient is a herbicide, e.g. a a phenoxypropionic acid herbicide or a sulfonylurea herbicide, and especially Quizalofop-ethyl or Halosulfuron-methyl.

The designation of the inventor has not yet been filed

263

78 FR 9688 - Pesticides; Draft Guidance for Pesticide Registrants on Antimicrobial Pesticide Products With...  

Science.gov (United States)

...on Antimicrobial Pesticide Products With Mold-Related Label Claims; Notice of Availability...for Antimicrobial Pesticide Products with Mold-Related Label Claims. This document...for antimicrobial pesticide products with mold-related claims. In response to...

2013-02-11

264

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

Science.gov (United States)

...on Antimicrobial Pesticide Products With Mold-Related Label Claims; Notice of Availability...on Antimicrobial Pesticide Products with Mold-Related Label Claims.'' PR Notices...efficacy) data and labeling for ``mold-related'' pesticide products....

2012-12-12

265

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

2005-01-01

266

Resistance to carbamate insecticides in Helicoverpa armigera (Lepidoptera: Noctuidae) in Pakistan.  

UK PubMed Central (United Kingdom)

The status of resistance to four carbamates viz. carbaryl, alanycarb, methomyl and thiodicarb was monitored in Pakistani populations of Helicoverpa armigera (Hubner) during 1994 to 1999 using an IRAC leaf-dip method. A general trend was that resistance to carbaryl, alanycarb and methomyl was high in 1994 and 1995, low in 1996 and 1997, and moderate to high in 1998 and 1999. Because of limited use of carbamates in Pakistan, this trend is not understood. It may be the consequence of cross-resistance from mechanisms developed for other insecticide groups. However, a broad cross-resistance was evident among carbaryl, alanycarb and methomyl. Surprisingly, a very low level of resistance to thiodicarb was found throughout this six-year study. No correlation of resistance factors existed between thiodicarb and carbaryl or methomyl. This lack of cross-resistance between thiodicarb and other carbamates in H. armigera is very encouraging for devising an insecticide resistance management strategy against this pest.

Ahmad M; Arif MI; Ahmad Z

2001-06-01

267

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

Directory of Open Access Journals (Sweden)

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

Lyubov Yotova; Nourelhoda Medhat

2011-01-01

268

[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

269

Lanthanum(III) isopropoxide catalyzed chemoselective transesterification of dimethyl carbonate and methyl carbamates.  

Science.gov (United States)

A practical transesterification of less reactive dimethyl carbonate and much less reactive methyl carbamates with primary (1°), secondary (2°), and tertiary (3°) alcohols was established with the use of a lanthanum(III) complex, which was prepared in situ from lanthanum(III) isopropoxide (3 mol %) and 2-(2-methoxyethoxy)ethanol (6 mol %). In particular, corresponding carbonates and carbamates obtained were of synthetic utility from the viewpoint of the selective protection and/or deprotection of 1°-, 2°-, and 3°-alcohols. PMID:21175159

Hatano, Manabu; Kamiya, Sho; Moriyama, Katsuhiko; Ishihara, Kazuaki

2010-12-22

270

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

Science.gov (United States)

The efficiency of biopurification systems to treat pesticide-contaminated water was previously studied in microcosms. To validate the obtained results, macrocosm systems were set-up. Four pesticides (linuron, isoproturon, bentazone, and metalaxyl) were continuously applied to ten different organic substrate mixes. Retention of the pesticides was similar and in some cases slightly lower in the macrocosms compared to the microcosms. Differences in retention between the different mixes were however minimal. Moreover, the classification of the retention strength of the pesticides was identical to that observed in microcosms: linuron>isoproturon>metalaxyl>bentazone. Monod kinetics were used to describe delayed degradation, which occurred for isoproturon, metalaxyl and bentazone. No breakthrough of linuron was observed, thus, this pesticide was appointed as the most retained and/or degraded pesticide, followed by isoproturon, metalaxyl and bentazone. Finally, most of the matrix mixes efficient in degrading or retaining pesticides were mixes containing dried cow manure. PMID:19144454

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

2009-01-13

271

Agricultural pesticide residues  

International Nuclear Information System (INIS)

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

1984-01-01

272

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 ...

Seth, P.K.

273

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.

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

2002-01-01

274

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

275

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

Science.gov (United States)

...2070-AJ74 Pesticide Management and Disposal; Standards for Pesticide Containers...rule titled ``Pesticide Management and Disposal; Standards for Pesticide Containers...regulations for the safe storage and disposal of pesticides to reduce the...

2010-10-08

276

Pesticides in seaweed: optimization of pressurized liquid extraction and in-cell clean-up and analysis by liquid chromatography-mass spectrometry.  

UK PubMed Central (United Kingdom)

Chemical residues, such as insecticides and anthelmintics, are frequently redistributed from the aquatic environment to marine species. This work reports on a fast validated protocol for the analysis of azamethiphos, three avermectins, two carbamates and two benzoylurea pesticides and chemotherapeutic agents in seaweeds based on pressurized liquid extraction and separation of analytes by liquid chromatography coupled with tandem mass spectrometry. The variables affecting the efficiency of pressurized liquid extraction, including temperature, number of extraction cycles, static extraction time and percent acetonitrile flush volume, were studied using a Doehlert design. The optimum parameters were 100 °C and one cycle of 3 min with 70 % acetonitrile. Adequate in-cell clean-up of the seaweeds was achieved using 0.8 g of Florisil over 0.1 g of graphitized carbon black on the bottom of the cell. The optimized method was validated using an analyte-free seaweed sample fortified at different concentrations. The limits of quantification ranged from 3.6 ?g kg(-1) (azamethiphos) to 31.5 ?g kg(-1) (abamectin). The recovery was from 87 to 120 % in most cases at different spiking levels. Finally, the reproducibility of the method expressed as the relative standard deviation and evaluated at concentrations of 10 and 50 ?g kg(-1) was in the range 9-14.3 % and 6.1-12.3 %, respectively. The applicability of the method was evaluated with five commercial and 12 wild edible seaweeds, and four target compounds were detected in two wild seaweeds at a concentration below the quantification limit.

Lorenzo RA; Pais S; Racamonde I; García-Rodríguez D; Carro AM

2012-07-01

277

Compound specific isotope analysis of the pesticides bentazone, MCPA, dichlobenil and its main metabolite BAM: Method validation and degradation studies Substanzspezifische Isotopenanalyse der Pestizide Bentazon, MCPA, Dichlobenil und dessen Metabolit BAM: Methoden Validierung und Abbaustudien  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In this work compound specific isotope analysis (CSIA) of the pesticides bentazone, MCPA, 2,6-dichlorobenzonitrile atrazine as well as their metabolites 2,6 dichlorobenzamide (BAM) and desethylatrazine were developed and optimized, respectively. CSIA has become a promising tool to determine the carb...

Reinnicke, Sandra

278

Disiloxanes with cyclic or non-cyclic carbamate moieties as electrolytes for lithium-ion batteries.  

UK PubMed Central (United Kingdom)

Novel liquid disiloxanes, containing an n-propylic spacer group between the disiloxane fragment and a cyclic or non-cyclic carbamate moiety, were synthesized and characterized as liquid electrolytes. The ionic conductivity, thermal properties, viscosity and relative permittivity of these new solvents have been investigated, taking into account steric factors.

Jeschke S; Gentschev AC; Wiemhöfer HD

2013-02-01

279

Effects of selected carbamate and organophosphate nematicides on hatching and emergence of Heterodera schachtii.  

UK PubMed Central (United Kingdom)

Ethoprop, oxamyl, PP 156, fenamiphos, carbofuran , AC 64,475, Bunema M, CG 12223, aldicarb, aldicarbsulfoxide, and aldicarbsulfone were tested for their effects on hatching and emergence of larvae from cysts of Heterodera schachtii. The oxime carbamates and carbofuran inhibited hatching , but this response was reversed by removing the chemical treatment . Inhibition of hatching by Bunema M and all organophosphates tested was irreversible .

Steele AE

1977-04-01

280

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

International Nuclear Information System (INIS)

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

1986-01-01

 
 
 
 
281

Synthesis of (carbonyl-/sup 14/C)labeled carbonate and carbamate esters  

Energy Technology Data Exchange (ETDEWEB)

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

Nassar, M.N.; Agha, B.J.; Digenis, G.A.

1986-06-01

282

Gold-catalyzed oxycyclization of allenic carbamates: expeditious synthesis of 1,3-oxazin-2-ones.  

UK PubMed Central (United Kingdom)

A combined experimental and computational study on regioselective gold-catalyzed synthetic routes to 1,3-oxazinan-2-ones (kinetically controlled products) and 1,3-oxazin-2-one derivatives (thermodynamically favored) from easily accessible allenic carbamates has been carried out.

Alcaide B; Almendros P; Quirós MT; Fernández I

2013-01-01

283

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)...

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

284

Free-radical carbo-alkenylation of enamides and ene-carbamates.  

UK PubMed Central (United Kingdom)

The addition of xanthates and vinyldisulfones across the double bond of enamides and ene-carbamates provides access to the corresponding three-component adducts in good to excellent yields with a high level of diastereocontrol in cyclic systems. This strategy illustrates a complementary reactivity for these versatile olefins and extends their scope of application.

Poittevin C; Liautard V; Beniazza R; Robert F; Landais Y

2013-06-01

285

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

International Nuclear Information System (INIS)

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

1996-01-01

286

Development of ratiometric near-infrared fluorescent probes using analyte-specific cleavage of carbamate.  

UK PubMed Central (United Kingdom)

We report a facile method to design NIR ratiometric fluorescent probes in terms of analyte-induced carbamate cleavage. Two examples, CyNB and CyNN3, exhibit a significant analyte-triggered response with ratiometric fluorescence change in the NIR range and dual-emission ratiometry in living cells.

Zhu D; Li G; Xue L; Jiang H

2013-07-01

287

Plant-parasitic NematodeAcetylcholinesterase Inhibition by Carbamate andOrganophosphate Nematicides  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The sensitivity of acetylcholinesterases (ACHE) isolated from the plant-parasitic nematodes Meloidogyne arenaria, M. incognita, and Heterodera glycines and the free-living nematode Caenorhabditis elegans to carbamate and organophosphate nematicides was examined. The AChE from plant-parasitic nematod...

Opperman, C. H.; Chang, S.

288

Asymmetric anti-aldol addition of achiral ketones via chiral N-amino cyclic carbamate hydrazones.  

UK PubMed Central (United Kingdom)

The asymmetric anti-aldol addition of ketone-derived donors and aldehyde acceptors is described. Asymmetric induction is achieved through the use of chiral N-amino cyclic carbamate (ACC) auxiliaries. The transformation exhibits essentially perfect anti-diastereoselectivity and enantioselectivity, and has the unusual feature of proceeding via thermodynamic, rather than kinetic control.

Knight JD; Coltart DM

2013-09-01

289

Osmium-catalyzed vicinal oxyamination of alkenes by N-(4-toluenesulfonyloxy)carbamates.  

UK PubMed Central (United Kingdom)

N-(4-toluenesulfonyloxy)carbamates based on a range of common amine protecting groups serve as preformed nitrogen sources in the intermolecular osmium-catalyzed oxyamination reaction of a variety of mono-, di-, and trisubstituted alkenes. The reactions occur with low catalyst loadings and good yields and afford high regioselectivity for unsymmetrically substituted alkenes.

Masruri; Willis AC; McLeod MD

2012-10-01

290

Buprofezin contained pesticide composition  

UK PubMed Central (United Kingdom)

The invention provides a buprofezin contained pesticide composition, which is prepared by the buprofezin hexaflumuron, indoxacarb, imidacloprid acetamiprid or pesticides, such as the remaining ingredients, complemented by conventional solvents, emulsifiers and synergist. The composition of the invention compounds different mechanisms of insecticide mixed together to expand the spectrum of prevention, one application, we can effectively combat a wide range of pests, can replace highly toxic pesticides, the role of various mechanisms, efficient broad-spectrum, low-characteristics of drugs to achieve a multi-drug administration and an effective solution to the resistance of rice pest problems.

ANHUI HUANG; QINFEI JIANG

291

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  

Directory of Open Access Journals (Sweden)

Full Text Available 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 (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.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 leite 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.

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

2011-01-01

292

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

2009-01-01

293

[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

294

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

UK PubMed Central (United Kingdom)

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.

Achour S; Khattabi A; Rhalem N; Ouammi L; Mokhtari A; Soulaymani A; Bencheikh RS

2011-05-01

295

Análise de pesticidas, aflatoxinas e análise de macro e microminerais de polpa cítrica peletizada comercial/ Pesticides, aflatoxins and macro and microminerals analyses of commercial citrus pulp pellets  

Scientific Electronic Library Online (English)

Full Text Available Abstract in english Pesticides, aflatoxins, and nutritional analyses of commercial citrus pulp pellets in Brazil were performed in samples from São Paulo State. They were stored during 86 days and were processed for detection of toxic agents. Residual pesticides (organochlorinated, organophosphorus, pyrethoids, carbamates, chloroalquil tio fungicides, triazols, and the miscellaneous compound propargit) and aflatoxins (B1, B2, G1 and G2) were assayed at 0, 43 and 86 days of storage. It was n (more) ot detected residual pesticide and aflatoxins in any sample. The analysis indicated reduced levels of phosphorous and high values of calcium. Assessment of micro minerals indicated the presence of aluminum, barium, titanium, cooper, manganese, thorium, vanadium, zinc, lanthanum, samarium, cobalt, antimony, arsenic, and scandium.

Oliveira, N.J.F.; Melo, M.M.; Lago, L.A.

2004-10-01

296

Illegal Pesticide Products  

Science.gov (United States)

Illegal Pesticide Products Esta página Web está disponible en español Quick Resources Protect your Business Counterfeit Flea ... reviewed for clear directions and safety warnings. Common Illegal Pest Products mothballs | pet products | insecticidal chalk | " Tres ...

297

Genotoxic effects of pesticides.  

UK PubMed Central (United Kingdom)

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

Kornuta N; Bagley E; Nedopitanskaya N

1996-01-01

298

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

Energy Technology Data Exchange (ETDEWEB)

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

Sanchez-Hernandez, Juan C. [Laboratory of Ecotoxicology, Faculty of Environmental Science, University of Castilla-La Mancha, 45071 Toledo (Spain)]. E-mail: juancarlos.sanchez@uclm.es; Carbonell, R. [Laboratory of Ecotoxicology, Faculty of Environmental Science, University of Castilla-La Mancha, 45071 Toledo (Spain); Henriquez Perez, A. [Laboratory of Ecotoxicology, Faculty of Environmental Science, University of Castilla-La Mancha, 45071 Toledo (Spain); Montealegre, M. [Laboratory of Ecotoxicology, Faculty of Environmental Science, University of Castilla-La Mancha, 45071 Toledo (Spain); Gomez, L. [Laboratory of Ecotoxicology, Faculty of Environmental Science, University of Castilla-La Mancha, 45071 Toledo (Spain)

2004-12-01

299

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

International Nuclear Information System (INIS)

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

2004-01-01

300

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

 
 
 
 
301

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

Scientific Electronic Library Online (English)

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

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

2008-01-01

302

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

Directory of Open Access Journals (Sweden)

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

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

2008-01-01

303

Effect of ether anaesthesia on pharmacokinetics of N-(2 hydroxy ethyl)2-phenyl ethyl carbamate: inhibition of its enterohepatic circulation.  

UK PubMed Central (United Kingdom)

1 The effect of the ether anaesthesia on the plasma half-life of N-(2 hydroxy ethyl) 2-phenyl ethyl carbamate has been studied in rats.2 The plasma half-life of the carbamate was considerably shorter in animals anaesthetized with ether prior to drug administration than in control rats.3 The longer plasma half-life of the carbamate in control animals was shown to be due to enterohepatic circulation.4 Inhibition of this phenomenon by ether was responsible for the shorter plasma half-life of the carbamate in animals anaesthetized with this agent before drug administration.5 The possible mechanisms by which the ether-induced effect is brought about are discussed.

Obianwu HO

1974-05-01

304

Process for the production of N-(2-Benzimidazolyl)-carbamic acid alkyl ester preparations for wood-protecting lacquers  

UK PubMed Central (United Kingdom)

Alkyl N-(2-benzimidazolyl)carbamate preparations for wood-protection paints having improved shelf life are obtained by transurethanisation of the carbamates using compounds which carry at least 2 hydroxyl groups. The hydroxyl compounds employed are diols, polyols, alkyd resins or partially diol-esterified adduct compounds. The fungicide polyol compounds may optionally be esterified or transesterified using fatty acids, alkyd resins or alkyd resin raw materials. The reaction takes place in the presence of organotin compounds as catalyst.

Awad Rami Dipl.-Ing.; Rauch-Puntigam Harald Dr.; Kriessmann Ingo Dr.

305

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

Science.gov (United States)

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

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

1991-01-01

306

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

Directory of Open Access Journals (Sweden)

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

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

2011-01-01

307

New Pesticide Face Sheet: Fipronil.  

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.

1996-01-01

308

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

UK PubMed Central (United Kingdom)

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

Ali A; Balkovec JM; Greenlee M; Hammond ML; Rouen G; Taylor G; Einstein M; Ge L; Harris G; Kelly TM; Mazur P; Pandit S; Santoro J; Sitlani A; Wang C; Williamson J; Forrest MJ; Carballo-Jane E; Luell S; Lowitz K; Visco D

2008-08-01

309

PROCESS FOR PREPARING METHYL CARBAMATE AND ITS PURIFICATION FOR USE AS PHARMACEUTICALLY ACTIVE COMPOUND  

UK PubMed Central (United Kingdom)

The present invention relates to processes for preparing methyl {4,6-diamino-2-[1-(2-fluorobenzyl)-1H-pyrazolo[3,4-b]pyridin-3-yl]pyrimidin-5-yl}carbamate, i.e. the compound of the formula (I) and to a process for purifying the crude product of the formula (I) for use as pharmaceutically active compound, where, for purification, methyl {4,6-diamino-2-[1-(2-fluorobenzyl)-1H-pyrazolo[3,4-b]pyridin-3-yl]pyrimidin-5-yl}carbamate sulphinyldimethane (1:2) of the formula (II) is isolated as intermediate or is generated as intermediate in this purification process, if appropriate present in a mixture.

MAIS FRANZ-JOSEF; REHSE JOACHIM; JOENTGEN WINFRIED; SIEGEL KONRAD

310

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

2013-07-08

311

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

Directory of Open Access Journals (Sweden)

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

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

2011-01-01

312

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

UK PubMed Central (United Kingdom)

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.

Guo X; Jia X; Du J; Xiao L; Li F; Liao L; Liu L

2013-10-01

313

Mild metal-free tandem ?-alkylation/cyclization of N-benzyl carbamates with simple olefins.  

UK PubMed Central (United Kingdom)

Easy does it! The chemoselective oxidative ?-C(sp(3))-H alkylation/cyclization reaction of N-benzyl carbamates using simple mono-, di-, and trisubstituted olefins provides functionalized N-heterocycles such as oxazinones. A TEMPO oxoammonium salt serves as the oxidant, making it possible to carry out the reaction at low temperatures. Neither a metal catalyst nor preactivation in the ?-position to the nitrogen group are needed.

Richter H; Fröhlich R; Daniliuc CG; García Mancheño O

2012-08-01

314

Synthesis of dimethyl carbonate from methyl carbamate and methanol over lanthanum compounds  

Energy Technology Data Exchange (ETDEWEB)

Various lanthanum compounds were used as the catalyst for the synthesis of dimethyl carbonate (DMC) from methyl carbamate and methanol. Among them, La(NO{sub 3}){sub 3} presented the best catalytic performance with the DMC yield of 53.7% under suitable reaction conditions. Based on the results of X-ray diffraction, Fourier transform infrared spectroscopy and element analysis, a possible reaction mechanism over lanthanum nitrate was proposed for this reaction. (author)

Wang, Dengfeng; Zhang, Xuelan; Gao, Yangyan [State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan, 030001 (China); Graduate university of Chinese, Academy of Sciences, Beijing, 100049 (China); Xiao, Fukui; Wei, Wei; Sun, Yuhan [State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan, 030001 (China)

2010-09-15

315

Clinical findings and cholinesterase levels in children of organophosphates and carbamates poisoning.  

UK PubMed Central (United Kingdom)

INTRODUCTION: Exposure to organophosphate and carbamate insecticides inhibits cholinesterase activity and interferes with synaptic transmission both centrally and peripherally at muscarinic receptors and nicotinic receptors. The study reported the usefulness of plasma cholinesterase ChE activity assays for diagnosis and the management of organophosphate and carbamate toxicity in children. METHODS: A retrospective study was conducted on children with organophosphate and carbamate poisoning. Forty-seven patients were included. The diagnosis was confirmed by measuring plasma cholinesterase levels. Atropine was given intravenous (0.02 mg/kg) and repeated until secretions were controlled. Obidoxime chloride was administered as 4-8 mg/kg/dose for children with organophosphate poisoning and to those in whom the ingested material was unidentified on admission. DISCUSSION: Most of the patients showed marked reactivation in plasma ChE within several hours and recovered completely within 24 h of admission. Complications were observed in 17 patients (36%). Mechanical ventilatory support was required in six patients. The duration intensive care stay was 3 +/- 2.4 days. CONCLUSION: Low plasma ChE levels support the diagnosis of insecticides poisoning, but no significant association is present between the severity of poisoning and plasma ChE levels. Atropine should be used as soon as possible to counteract the muscarinic effects. Appropriate management and early recognition of the complications may decrease the mortality rate.

El-Naggar Ael-R; Abdalla MS; El-Sebaey AS; Badawy SM

2009-08-01

316

Acetylcholinesterase biosensor for carbamate drugs based on tetrathiafulvalene-tetracyanoquinodimethane/ionic liquid conductive gels.  

UK PubMed Central (United Kingdom)

A highly sensitive acetylcholinesterase biosensor was developed for detection of carbamate drugs based on TTF-TCNQ-ionic liquid gel thiocholine sensor. The TTF-TCNQ-ionic/ionic liquid gel was characterized by FT-IR and scanning electron microscopy. The electrocatalytic behavior of TTF-TCNQ-ionic liquid gels toward oxidation of thiocholine was thoroughly investigated. 1-Ethyl-3-methylimidazolium tetracyanoborate gel based sensor allowed amperometric detection of thiocholine at +400 mV vs. Ag/AgCl with a high sensitivity of 55.9±1.2 ?A mM(-1)cm(-2) and a low detection limit equal to 7.6 ?M. The catalytic rate constant and diffusion constant of thiocholine were estimated from chronoamperometric data. The proposed biosensor based on AChE immobilized in sol-gel matrix was used for the detection of two carbamate therapeutic drugs. Very low detection limits of 26 pM eserine and 0.3 nM neostigmine were achieved. The analysis of spiked tap water proved the biosensor capability to be used as a screening method for detection of carbamate drugs in wastewaters.

Zamfir LG; Rotariu L; Bala C

2013-08-01

317

Bactericidal pesticide composition  

UK PubMed Central (United Kingdom)

The invention relates to a sterilization pesticide composition, which comprises effective drug ingredients of isoprothiolane and triazole fungicide as well as pesticide-acceptable auxiliary components, wherein the weight ratio of the isoprothiolane to the triazole fungicide is 40:1-1: 60. By the synergy generated by the combination of two effective drug ingredients with different sterilization mechanisms, the sterilization pesticide composition can improve the sterilizing effect and the using safety remarkably, and can reduce the using cost. The composition can be prepared into different dosage forms of missible oil, wettable powders, suspensions, emulsions, granules, and the like for preventing and treating plant diseases caused by the majority of pathogenic fungi such as ascomycetes, basidiomycetes and imperfect fungi, in particular cereal crop diseases such as rice blast and sheath blight, wheat sheath blight, and the like.

LIXIANG XING; XIANG LI; LIJUN DONG

318

Tutin derivative pesticide  

UK PubMed Central (United Kingdom)

The invention relates to a botanical pesticide, namely a tutin derivative pesticide, which comprises various restructuring substances of tutin, such as an alpha-methyl-propylene acylated derivative pesticide. An alpha-methyl-propylene acylated derivative of the tutin is obtained by performing 2 position hydroxyl acylation reconstructing by taking the tutin as a template, and the derivative has colorless crystals and a molecular formula of C19H22O7. Bioactive determination results show that under low concentration of 2.00 mg/mL, the derivative increases the antifeedant activity to armyworm by 55.49 percent compared with the tutin, the antifeedant activity reaches 85 percent, and the derivative can lead trial insects to death.

MENGLOU LI; CUI JUN

319

Pesticide composition containing nitenpyram  

UK PubMed Central (United Kingdom)

The invention discloses a pesticide composition containing nitenpyram, which comprises two active ingredients: A is the nitenpyram, and B is one selected from chlorpyrifos-methyl, chlorantraniliproleand metaflumizone and based on the parts by weight of the two active ingredients, the proportion between the components A and B is 1:20-20:1. The pesticide composition can be prepared into missible oil, wetting powder, emulsion in water, microemulsion, suspending agent and water dispersible granules, wherein the weight percentage content of the active ingredients is 5-85%. The pesticide composition has the function(s) of synergy and/or expansion of prevention and treatment spectrum, and can be used for controlling pests such as rice planthopper of rice, cnaphalocrocis medinalis guenee, chilosuppressalis, tryporyza incertulas, rice skipper butterfly and the like as well as aphid, white fly, thrips palmi karny, flea beetle, prodenia litura, spodoptera exigua and the like of commercial crops such as cotton, vegetables and the like.

FAN CHEN; CHAOAI ZHOU; QIYIN JIANG; XIAODI CAO

320

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

2010-11-27

 
 
 
 
321

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

UK PubMed Central (United Kingdom)

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.

Kojima H; Sata F; Takeuchi S; Sueyoshi T; Nagai T

2011-02-01

322

On the paradox of pesticides  

CERN Multimedia

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

323

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

324

Hayes' handbook of pesticide toxicology.  

Canada Institute for Scientific and Technical Information (Canada)

The Handbook of Pesticide Toxicology is a comprehensive, two-volume reference guide to the properties, effects, and regulation of pesticides that provides the latest and most complete information to researchers investigating the environmental, agricultural, veterinary, and human-health impacts of pesticide use. Written by international experts from academia, government, and the private sector, the Handbook of Pesticide Toxicology is an in-depth examination of critical issues related to the need for, use of, and nature of chemicals used in modern pest management. This updated third edition carries on the book's tradition of serving as the definitive reference on pesticide toxicology and recognizies the seminal contribution of Wayland J. Hayes, Jr., co-Editor of the first edition. Feature: Presents a comprehensive look at all aspects of pesticide toxicology in one reference work. Benefit: Saves researchers time in quickly accessing the very latest definitive details on toxicity of specific pesticides as opposed to searching through thousands of journal articles. Feature: Clear exposition of hazard identification and dose response relationships in each chapter featuring pesticide agents and actions Benefit: Connects the experimental laboratory results to real-life applications in human health, animal health and the environment. Feature: All major classes of pesticide considered. Benefit: Provides relevance to a wider variety of researchers who are conducting comparative work in pesticides or their health impacts. Feature: Different routes of exposure critically evaluated. Benefit: Connects the loop between exposure and harmful affects to those who are researching the affects of pesticides on humans or wildlife.

325

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

Directory of Open Access Journals (Sweden)

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

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

2012-01-01

326

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

UK PubMed Central (United Kingdom)

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.

Linhares AG; Assis CR; Siqueira MT; Bezerra RS; Carvalho LB Jr

2013-08-01

327

PROTEINS WITH PESTICIDAL ACTIVITY  

UK PubMed Central (United Kingdom)

The invention relates to new classes of pesticidally active proteins and polynucleotide sequences that encode these proteins. According to the invention, the proteins have molecular weights of approximately 40...50 kDa and approximately 10...15 kDa.

NARVA E KENNETH; SCHNEPF H ERNEST; KNUTH MARK; POLLARD R MICHAEL; CARDINEAU A GUY; SCHWAB E GEORGE; MICHAELS TRACY ELLIS; FINSTAD LEE STACY; DIEHL PAULA; DOJILLO JOANNA; STAMP LISA; HERMAN A ROD

328

Pesticides and childhood cancer.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Children are exposed to potentially carcinogenic pesticides from use in homes, schools, other buildings, lawns and gardens, through food and contaminated drinking water, from agricultural application drift, overspray, or off-gassing, and from carry-home exposure of parents occupationally exposed to ...

Zahm, S H; Ward, M H

329

Genotoxic effects of pesticides.  

Science.gov (United States)

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

Kornuta, N; Bagley, E; Nedopitanskaya, N

1996-01-01

330

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

International Nuclear Information System (INIS)

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

1985-01-01

331

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; Juliano de Almeida Andrade; Sonia Claudia do Nascimento de Queiroz

2009-01-01

332

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

Science.gov (United States)

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 and 2 and cytomegalovirus were negative for susceptibility to enhancement when either laboratory-adapted or wild-type strains were tested. No difference in the pattern of susceptibility was detected whether virus yields were determined by cell-associated or cell-free virus assay or when the input multiplicity was varied 10-fold. PMID:6307144

Jerkofsky, M; Abrahamsen, L H

1983-05-01

333

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

UK PubMed Central (United Kingdom)

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 and 2 and cytomegalovirus were negative for susceptibility to enhancement when either laboratory-adapted or wild-type strains were tested. No difference in the pattern of susceptibility was detected whether virus yields were determined by cell-associated or cell-free virus assay or when the input multiplicity was varied 10-fold.

Jerkofsky M; Abrahamsen LH

1983-05-01

334

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

335

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

336

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

UK PubMed Central (United Kingdom)

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.

Suzuki T; Yaguchi K; Suzuki S; Suga T

2001-01-01

337

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; Xiaojuan Yang; Fulin Yan

2011-01-01

338

Aryl methylcarbamates: potency and selectivity towards wild-type and carbamate-insensitive (G119S) Anopheles gambiae acetylcholinesterase, and toxicity to G3 strain An. gambiae.  

UK PubMed Central (United Kingdom)

New carbamates that are highly selective for inhibition of Anopheles gambiae acetylcholinesterase (AChE) over the human enzyme might be useful in continuing efforts to limit malaria transmission. In this report we assessed 34 synthesized and commercial carbamates for their selectivity to inhibit the AChEs found in carbamate-susceptible (G3) and carbamate-resistant (Akron) An. gambiae, relative to human AChE. Excellent correspondence is seen between inhibition potencies measured with carbamate-susceptible mosquito homogenate and purified recombinant wild-type (WT) An. gambiae AChE (AgAChE). Similarly, excellent correspondence is seen between inhibition potencies measured with carbamate-resistant mosquito homogenate and purified recombinant G119S AgAChE, consistent with our earlier finding that the Akron strain carries the G119S mutation. Although high (100- to 500-fold) WT An. gambiae vs human selectivity is observed for several compounds, none of the carbamates tested potently inhibits the G119S mutant enzyme. Finally, we describe a predictive model for WT An. gambiae tarsal contact toxicity of the carbamates that relies on inhibition potency, molecular volume, and polar surface area.

Wong DM; Li J; Lam PC; Hartsel JA; Mutunga JM; Totrov M; Bloomquist JR; Carlier PR

2013-03-01

339

Ab Initio Study of CO2 Capture Mechanisms in Aqueous Monoethanolamine: Reaction Pathways for the Direct Interconversion of Carbamate and Bicarbonate.  

UK PubMed Central (United Kingdom)

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

Matsuzaki Y; Yamada H; Chowdhury FA; Higashii T; Onoda M

2013-09-01

340

Ab Initio Study of CO2 Capture Mechanisms in Aqueous Monoethanolamine: Reaction Pathways for the Direct Interconversion of Carbamate and Bicarbonate.  

Science.gov (United States)

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

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

2013-09-17

 
 
 
 
341

Soil column leaching of pesticides.  

UK PubMed Central (United Kingdom)

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

Katagi T

2013-01-01

342

Soil column leaching of pesticides.  

Science.gov (United States)

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

Katagi, Toshiyuki

2013-01-01

343

Preparation of bifunctional isocyanate hydroxamate linkers: Synthesis of carbamate and urea tethered polyhydroxamic acid chelators.  

UK PubMed Central (United Kingdom)

Two novel bifunctional N-methylhydroxamate-isocyanate linkers 20 and 21 were prepared in good yield and high purity from the corresponding amine salts using a biphasic reaction with phosgene. The facile ring opening reaction of N-Boc lactams using the anion of O-benzylhydroxylamine gave the protected amino hydroxamates 6a and 6c in good yields. The selective methylation of the hydroxamate nitrogen in the presence of the N-Boc group in these intermediates could be readily accomplished. The utility of the linkers was clearly demonstrated by the synthesis of the carbamate-tethered trishydroxamic acid 27 and the urea-tethered 29.

Fernando R; Shirley JM; Torres E; Jacobs HK; Gopalan AS

2012-11-01

344

Vinyl carbonates, vinyl carbamates, and related monomers: synthesis, polymerization, and application.  

Science.gov (United States)

Although acrylates and methacrylates are the state-of-the-art monomers for protective and decorative coatings, skin and inhalation irritancy and potential cytotoxicity of monomers present serious health hazards. Monomers like vinyl carbonates or vinyl carbamates can overcome these problems with their generally lower cytotoxicity and yet similar photoreactivity to (meth)acrylates. The reviewed classes of monomers have not attracted industry's attention until now due to expensive synthetic methods though recently developed affordable routes offer prospect for their increasing use (88 references). PMID:22109626

Husár, Branislav; Liska, Robert

2011-11-22

345

Synthesis and evaluation of carbamate prodrugs of SQ109 as antituberculosis agents.  

UK PubMed Central (United Kingdom)

The low bioavailability of SQ109 in rats, resulting from first-pass effect in the liver, may be remedied by prodrug strategy. Based on esterase-sensitive carbamate prodrug strategy, a novel series of prodrugs of SQ109 has been reported. Bioavailability of SQ109 after administration of prodrug 7a was 91.4% compared with 21.4% after oral administration of SQ109. After oral administration of compound 7a, the parent drug SQ109 exhibited preferential tissue distribution into lung and spleen, the target organs of tubercular infection and replication.

Meng Q; Luo H; Liu Y; Li W; Zhang W; Yao Q

2009-05-01

346

Synthesis and evaluation of carbamate prodrugs of SQ109 as antituberculosis agents.  

Science.gov (United States)

The low bioavailability of SQ109 in rats, resulting from first-pass effect in the liver, may be remedied by prodrug strategy. Based on esterase-sensitive carbamate prodrug strategy, a novel series of prodrugs of SQ109 has been reported. Bioavailability of SQ109 after administration of prodrug 7a was 91.4% compared with 21.4% after oral administration of SQ109. After oral administration of compound 7a, the parent drug SQ109 exhibited preferential tissue distribution into lung and spleen, the target organs of tubercular infection and replication. PMID:19362471

Meng, Qingyi; Luo, Huibing; Liu, Yibin; Li, Wei; Zhang, Wen; Yao, Qizheng

2009-03-26

347

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

Science.gov (United States)

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

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

1996-01-01

348

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

UK PubMed Central (United Kingdom)

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

Gliniewicz A; Krzemi?ska A; Sawicka B

1996-01-01

349

Polyamine analysis using N-hydroxysuccinimidyl-6-aminoquinoyl carbamate for pre-column derivatization.  

UK PubMed Central (United Kingdom)

N-Hydroxysuccinimidyl-6-aminoquinoyl carbamate (AccQ.Fluor) was used as a polyamine pre-column derivatization reagent prior to HPLC analysis using a 5-micron C8 reversed-phase column. The fluorescence detector excitation wavelength was set at 250 nm and emission at 395 nm. Quantitation, reproducibility, linearity, recovery and stability were demonstrated. The lower limit of detection was 660 fmol. This method is 45 and 61 times more sensitive than those using the pre-column derivatizing agents dansyl chloride and orthophthalaldehyde, respectively. Applicability to biological samples was demonstrated by analyses of polyamines in extracts of mouse erythrocytes and Trypanosoma brucei brucei.

Merali S; Clarkson AB Jr

1996-01-01

350

Polyamine analysis using N-hydroxysuccinimidyl-6-aminoquinoyl carbamate for pre-column derivatization.  

Science.gov (United States)

N-Hydroxysuccinimidyl-6-aminoquinoyl carbamate (AccQ.Fluor) was used as a polyamine pre-column derivatization reagent prior to HPLC analysis using a 5-micron C8 reversed-phase column. The fluorescence detector excitation wavelength was set at 250 nm and emission at 395 nm. Quantitation, reproducibility, linearity, recovery and stability were demonstrated. The lower limit of detection was 660 fmol. This method is 45 and 61 times more sensitive than those using the pre-column derivatizing agents dansyl chloride and orthophthalaldehyde, respectively. Applicability to biological samples was demonstrated by analyses of polyamines in extracts of mouse erythrocytes and Trypanosoma brucei brucei. PMID:8852721

Merali, S; Clarkson, A B

1996-01-26

351

Renewable Non-Isocyanate Based Thermoplastic Polyurethanes via Polycondensation of Dimethyl Carbamate Monomers with Diols.  

UK PubMed Central (United Kingdom)

1,5,7-Triazabicyclo[4.4.0]dec-5-ene (TBD)-catalyzed polycondensation reactions of fatty acid derived dimethyl dicarbamates and diols are introduced as a versatile, non-isocyanate route to renewable polyurethanes. The key step for the synthesis of dimethyl carbamate monomers from plant-oil-derived dicarboxylic acids is based on a sustainable base-catalyzed Lossen rearrangement. The formed polyurethanes with molecular weights up to 25 kDa are characterized by SEC, DSC, and NMR analysis. via size exclusion chromatography (SEC), differential scanning calorimetry (DSC) and nuclear magnetic resonance (NMR).

Unverferth M; Kreye O; Prohammer A; Meier MA

2013-09-01

352

Vinyl carbonates, vinyl carbamates, and related monomers: synthesis, polymerization, and application.  

UK PubMed Central (United Kingdom)

Although acrylates and methacrylates are the state-of-the-art monomers for protective and decorative coatings, skin and inhalation irritancy and potential cytotoxicity of monomers present serious health hazards. Monomers like vinyl carbonates or vinyl carbamates can overcome these problems with their generally lower cytotoxicity and yet similar photoreactivity to (meth)acrylates. The reviewed classes of monomers have not attracted industry's attention until now due to expensive synthetic methods though recently developed affordable routes offer prospect for their increasing use (88 references).

Husár B; Liska R

2012-03-01

353

Synthesis of dimethyl carbonate from methyl carbamate and methanol using a Fixed-Bed reactor  

Energy Technology Data Exchange (ETDEWEB)

Several mixed oxide catalysts were prepared by coprecipitation for dimethyl carbonate (DMC) synthesis from methyl carbamate and methanol. During the batch process, the DMC yield was below 35 %. In order to minimize the unfavorable thermodynamic equilibrium and side reactions for the DMC synthesis, a fixed-bed reactor was designed. A maximum DMC yield of {proportional_to} 73 % could be realized over a ZnO-Al{sub 2}O{sub 3} catalyst. The effects of reaction conditions for this type of reactor were investigated in detail. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Wang, D. [Zaozhuang University, College of Chemistry, Chemical Engineering and Materials Science, Zaozhuang (China); Zhang, X. [Zaozhuang University, College of Chemistry, Chemical Engineering and Materials Science, Zaozhuang (China); Chinese Academy of Sciences, Institute of Coal Chemistry, State Key Laboratory of Coal Conversion, Taiyuan (China); Wei, W.; Sun, Y. [Chinese Academy of Sciences, Institute of Coal Chemistry, State Key Laboratory of Coal Conversion, Taiyuan (China)

2012-12-15

354

Equilibrium constant for carbamate formation from monoethanolamine and its relationship with temperature  

Energy Technology Data Exchange (ETDEWEB)

Removal of acid gases such as CO{sub 2} and H{sub 2}S using aqueous solutions of alkanolamines is an industrially important process. The equilibrium constant for the formation of carbamate from monoethanolamine was evaluated at various temperatures of 298, 308, 318, and 328 K and ionic strengths up to 1.7 M. From the plot of log{sub 10} K versus I{sup 0.5}, the variation of the thermodynamical constant with temperature follows the relationship log{sub 10} K{sub 1} = {minus}0.934 + (0.671 {times} 10{sup 3})K/T.

Aroua, M.K.; Benamor, A.; Haji-Sulaiman, M.Z. [Univ. of Malaya, Kuala Lumpur (Malaysia). Dept. of Chemical Engineering

1999-09-01

355

Determination of five pesticide residues in oranges by matrix solid-phase dispersion and liquid chromatography to estimate daily intake of consumers.  

Science.gov (United States)

Residues of benzoylphenylurea insecticides (diflubenzuron, hexaflumuron, and flufenuxuron), carboxamide acaricides (hexythiazox), and carbamate insecticides (benfuracarb) were determined in 150 orange fruit samples from September 1998 to June 1999, to estimate exposure of the Valencian population to oranges contaminated with these newly developed pesticides. The method for monitoring these residues is based on matrix solid-phase dispersion and liquid chromatography with UV or atmospheric pressure chemical ionization/mass spectrometry (APCI/MS) detection. Orange samples representing 11 varieties were collected from an agricultural cooperative and examined for the 5 pesticides. In 74.6% of all analyzed samples, the pesticide residues were below detection limits, which ranged from 0.002 to 0.05 mg/kg. Residues were detected in 25.4% of the samples, with higher incidences of diflubenzuron, flufenuxuron, hexythiazox, and benfuracarb; hexaflumuron residues were detected only occasionally. Two different pesticides exceeded maximum residue limits (MRLs) in 4 (2.7%) of the orange samples. Diflubenzuron surpassed 1 mg/kg MRL in 3 samples and flufenuxuron exceeded the 0.3 mg/kg MRL in 3 samples. The estimated daily intake of the 5 pesticide residues during the period was 0.077 microg/kg body weight per day. This value is much lower than the total admissible daily intake proposed by the Food and Agricultural Organization and the World Health Organization. PMID:11417653

Valenzuela, A I; Picó, Y; Font, G

356

Determination of five pesticide residues in oranges by matrix solid-phase dispersion and liquid chromatography to estimate daily intake of consumers.  

UK PubMed Central (United Kingdom)

Residues of benzoylphenylurea insecticides (diflubenzuron, hexaflumuron, and flufenuxuron), carboxamide acaricides (hexythiazox), and carbamate insecticides (benfuracarb) were determined in 150 orange fruit samples from September 1998 to June 1999, to estimate exposure of the Valencian population to oranges contaminated with these newly developed pesticides. The method for monitoring these residues is based on matrix solid-phase dispersion and liquid chromatography with UV or atmospheric pressure chemical ionization/mass spectrometry (APCI/MS) detection. Orange samples representing 11 varieties were collected from an agricultural cooperative and examined for the 5 pesticides. In 74.6% of all analyzed samples, the pesticide residues were below detection limits, which ranged from 0.002 to 0.05 mg/kg. Residues were detected in 25.4% of the samples, with higher incidences of diflubenzuron, flufenuxuron, hexythiazox, and benfuracarb; hexaflumuron residues were detected only occasionally. Two different pesticides exceeded maximum residue limits (MRLs) in 4 (2.7%) of the orange samples. Diflubenzuron surpassed 1 mg/kg MRL in 3 samples and flufenuxuron exceeded the 0.3 mg/kg MRL in 3 samples. The estimated daily intake of the 5 pesticide residues during the period was 0.077 microg/kg body weight per day. This value is much lower than the total admissible daily intake proposed by the Food and Agricultural Organization and the World Health Organization.

Valenzuela AI; Picó Y; Font G

2001-05-01

357

PESTICIDE COMPOSITIONS INCLUDING POLYMERIC ADJUVANTS  

UK PubMed Central (United Kingdom)

Pesticidal compositions of improved effectiveness are provided, including a pesticide (e.g., an insecticide or herbicide) together with a copolymer adjuvant or additive selected from the group consisting of acid or salt copolymers containing individual quantities of maleic and itaconic moieties. The compositions of the invention provide multiple-fold increases in effectiveness, as compared with an equal amount of the pesticide in the absence of the copolymer.

SANDERS JOHN LARRY

358

Pesticide exposure--Egyptian scene.  

UK PubMed Central (United Kingdom)

Pesticides have contributed to dramatic increases in crop yields and in the quantity and variety of the diet. Also, they have helped to limit the spread of certain diseases. But pesticides have harmful effects; they can cause injury to human health as well as to the environment. The range of these adverse health effects includes acute and persistent injury to the nervous system, lung damage, injury to the reproductive organs, dysfunction of the immune and endocrine systems, birth defects, and cancer. Problems associated with pesticide hazards to man and the environment are not confined to the developing countries. Developed nations have already suffered these problems, and still facing some problems in certain locations. For many reasons, the severity of pesticide hazards is much pronounced in Third World Countries. A number of long persistent organochlorines and highly toxic organophosphates, which have been banned or severely restricted, are still marketed and used in many developing countries. The misuse of pesticides by concerned individuals, in addition to lack of or weak national controlling plans are behind the outbreak of adverse effects in developing countries. Since about 25 years, the use of DDT and many other organochlorine pesticides in Egyptian agriculture has been banned. However, these long persistent compounds are still detectable in many different types of environmental samples (e.g., water, fish, sediment, vegetables, fruits, milk, foodstuffs, etc.). Large number of compounds known as "extremely hazardous", "highly hazardous", "probable human carcinogenic", and "possible human carcinogenic", are listed among the pesticides registered and recommended for use in Egypt during the season of 2001/2002. The present article deals with: trends and patterns of pesticide use, impact of pesticides on human health, factors contributing to pesticide risks, environmental impacts of pesticides, and bioaccumulation of pesticide residues in food; giving special concern to the situation in Egypt.

Mansour SA

2004-05-01

359

Application of borneol in pesticides  

UK PubMed Central (United Kingdom)

The invention relates to an application of borneol in pesticides, which uses natural borneol or synthetic borneol in the aspects of repelling insects and killing bacteria by using the pesticides. An inventor independently uses the borneol or compounds with other pesticides for processing into formulations like wettable powder, missible oil, suspension, water dispersible granules, emulsion in water, smoke agent and the like, thereby having good effects in the aspects of killing bacteria, repelling inspects and the like.

JIANGUO ZENG; LI YAO; XUAN PENG; LI YUAN

360

Patrón de uso y venta de plaguicidas en Nayarit, México/ Pattern of use and sale of pesticides in Nayarit, Mexico  

Scientific Electronic Library Online (English)

Full Text Available Abstract in spanish Los plaguicidas son compuestos ampliamente utilizados en la agricultura y para controlar vectores que transmiten enfermedades a hombres y animales. Se investigó el patrón actual de venta y uso de plaguicidas en Nayarit, uno de los principales estados agrícolas en México; estos datos no existen en la literatura. Se aplicó una encuesta a los encargados de los establecimientos de venta de agroquímicos en el estado; de acuerdo a los resultados, los insecticidas son los (more) plaguicidas más frecuentemente empleados (45.9 %), seguidos de los herbicidas (30.5 %), fungicidas (20.1 %), entre otros. En cuanto a los grupos químicos, los organofosforados son los más vendidos y usados, seguidos de los piretroides, carbamatos y organoclorados. Contar con una base de datos completa y actual de los plaguicidas que se comercializan y en consecuencia se usan en cada una de las regiones de Nayarit, sentará las bases para futuros estudios que evalúen los efectos adversos de estos contaminantes sobre la salud humana y los ecosistemas. Abstract in english Pesticides are compounds widely used in agriculture and for the control of vectors that transmit diseases to humans and animals. No studies, however, have provided data regarding the potential use of pesticides in Nayarit State, one of the main agricultural states in México. This paper presents the use of pesticides in Nayarit by obtaining the rate of their sales via a direct interview with establishment retailers. The data indicate that insecticides are the most used ag (more) rochemicals (45.9 %) in Nayarit State, followed by herbicides (30.5 %) and fungicides (20.1 %). According to chemical classification, organophosphates are the most sold and used pesticides in the State, followed by pyretroids, carbamates and organochlorine pesticides. This study provides detailed and updated data about the pesticide sales and their consequent use in each region of Nayarit. This database may serve as a background for future studies evaluating adverse effects of these environmental contaminants on human health and ecosystems.

GONZÁLEZ-ARIAS, Cyndia Azucena; ROBLEDO-MARENCO, María de Lourdes; MEDINA-DÍAZ, Irma Martha; VELÁZQUEZ-FERNÁNDEZ, Jesús Bernardino; GIRÓN-PÉREZ, Manuel Iván; QUINTANILLA-VEGA, Betzabet; OSTROSKY-WEGMAN, Patricia; PÉREZ-HERRERA, Norma Elena; ROJAS-GARCÍA, Aurora Elizabeth

2010-08-01

 
 
 
 
361

Pesticide Residue Monitoring Program 1996  

Science.gov (United States)

... Ofurace Omethoate* Ovex Oxadiazon Oxadixyl Oxamyl* Oxydemeton-methyl Oxyfluorfen Oxythioquinox Paclobutrazol Paraquat* Parathion ... More results from www.fda.gov/Food/FoodborneIllnessContaminants/Pesticides

362

Pesticide Monitoring Program FY 2007  

Science.gov (United States)

... salithion; schradan; simazine; simetryne; sodium benzoate *; spirodiclofen *; strobane; sulfallate; sulfotepp; sulphenone; sulprofos ... More results from www.fda.gov/food/foodborneillnesscontaminants/pesticides

363

Pesticidal compound mixtures  

UK PubMed Central (United Kingdom)

The present invention relates to novel pesticidal combinations comprising ethiprole as component A and pyrethroids as component B comprised of acrinathrin, allethrin (d-cis-trans, d-trans), beta-cyfluthrin, tefluthrin, cyhalothrin, lambda-cyhalothrin, deltamethrin, bifenthrin, bioallethrin, bioallethrin-s-cyclopentyl-isomer, bioethanomethrin, biopermethrin, bioresmethrin, chlovaporthrin, cis-cypermethrin, cis-resmethrin, cis-permethrin, clocythrin, cycloprothrin, cyhalothrin, cypermethrin (alpha-, beta-, theta-, zeta-), cyphenothrin, empenthrin (IR-isomer), esfenvalerate, etofenprox, fenfluthrin, fenpropathrin, fenpyrithrin, fenvalerate, flubrocythrinate, flucythrinate, flufenprox, flumethrin, fluvalinate, fubfenprox, gamma-cyhalothrin, imiprothrin, kadethrin, metofluthrin, permethrin (cis-, trans-), phenothrin (1R-trans isomer), prallethrin, profluthrin, protrifenbute, pyresmethrin,; resmethrin, RU 15525, silafluofen, tau-fluvalinate, terallethrin, tetramethrin (IR-isomer), tralocythrin, tralomethrin, transfluthrin, ZXI 8901, pyrethrins (pyrethrum), that show surprisingly good pesticidal and activities.

364

Pesticidal Compound Mixtures  

UK PubMed Central (United Kingdom)

The present invention relates to novel pesticidal combinations comprising ethiprole as component A and pyrethroids as component B comprised of acrinathrin, allethrin, allethrin (d-cis-trans, d-trans), beta-cyfluthrin, tefluthrin, cyhalothrin, lambda-cyhalothrin, deltamethrin, bifenthrin, bioallethrin, bioallethrin-s-cyclopentyl-isomer, bioethanomethrin, biopermethrin, bioresmethrin, chlovaporthrin, cis-cypermethrin, cis-resmethrin, cis-permethrin, clocythrin, cycloprothrin, cyhalothrin, cypermetkrin (alpha-, beta-, theta-, zeta-), cyphenothrin, empenthrin (1 R-isomer), esfenvalerate, etofenprox, fenfluthrin, fenpropathrin, fenpyrithrin, fenvalerate, flubrocythrinate, flucythriate, flufenprox, flumethrin, fluvalinate, fubfenprox, gamma-cyhalothrin, imiprothrin, kadethrin, metofluthrin, permethrin (cis-, trans-), phenothrin (1 R-trans isomer), prallethrin, profluthrin, protrifenbute, pyresmethrin, resmethrin, RU 15525, silafluofen, tau-fluvahnate, terallethrin, tetramethrin (1 R-isomer), tralocythrin, tralomethrin, transfluthrin, ZXI 8901, pyrethrins (pyrethrum), that show surprisingly good pesticidal and activities

HUNGENBERG HEIKE; VELDEN TORSTEN; THIELERT WOLFGANG; TESSON ERIC

365

PESTICIDAL COMPOUND MIXTURES  

UK PubMed Central (United Kingdom)

The present invention relates to novel pesticidal combinations comprising ethiprole as component A and pyrethroids as component B comprised of acrinathrin, allethrin, allethrin (d-cis-trans, d-trans), beta-cyfluthrin, tefluthrin, cyhalothrin, lambda-cyhalothrin, deltamethrin, bifenthrin, bioallethrin, bioallethrin-s-cyclopentyl-isomer, bioethanomethrin, biopermethrin, bioresmethrin, chlovaporthrin, cis-cypermethrin, cis-resmethrin, cis-permethrin, clocythrin, cycloprothrin, cyhalothrin, cypermetkrin (alpha-, beta-, theta-, zeta-), cyphenothrin, empenthrin (1 R-isomer), esfenvalerate, etofenprox, fenfluthrin, fenpropathrin, fenpyrithrin, fenvalerate, flubrocythrinate, flucythriate, flufenprox, flumethrin, fluvalinate, fubfenprox, gamma-cyhalothrin, imiprothrin, kadethrin, metofluthrin, permethrin (cis-, trans-), phenothrin (1 R-trans isomer), prallethrin, profluthrin, protrifenbute,; pyresmethrin, resmethrin, RU 15525, silafluofen, tau-fluvahnate, terallethrin, tetramethrin (1 R-isomer), tralocythrin, tralomethrin, transfluthrin, ZXI 8901, pyrethrins (pyrethrum), that show surprisingly good pesticidal and activities

HUNGENBERG HEIKE; VELDEN TORSTEN; THIELERT WOLFGANG; TESSON ERIC

366

Radiation induced microbial pesticide  

International Nuclear Information System (INIS)

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

2000-01-01

367

Pesticidal emulsifiable concentrate composition  

UK PubMed Central (United Kingdom)

There is provided a novel pesticidal emulsifiable concentrate composition that contains a phenoxypropionate herbicide (e.g., quizalofop-p-ethyl), a polar solvent (e.g., N-methyl-2-pyrrolidone), non-polar solvent (e.g., aromatic or aliphatic hydrocarbon) and a surfactant (e.g., polyoxyethylene castor oil ether, polyoxyethylene styryl phenyl ether), and that is improved in low-temperature stability and emulsion stability.

KOBAYASHI MAMORU

368

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

UK PubMed Central (United Kingdom)

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

Navrátilová H; Opatrilová R; Kríz Z; Koca J

2004-03-01

369

Synthesis and biological activity of carbamate-linked cationic lipids for gene delivery in vitro.  

UK PubMed Central (United Kingdom)

We have introduced a convenient synthesis method for carbamate-linked cationic lipids. Two cationic lipids N-[1-(2,3-didodecylcarbamoyloxy)propyl]-N,N,N-trimethylammonium iodide (DDCTMA) and N-[1-(2,3-didodecyl carbamoyloxy)propyl]-N-ethyl-N,N-dimethylammonium iodide (DDCEDMA), with identical length of hydrocarbon chains, alternative quaternary ammonium heads, carbamate linkages between hydrocarbon chains and quaternary ammonium heads, were synthesized for liposome-mediated gene delivery. Liposomes composed of DDCEDMA and DOPE in 1:1 ratio exhibited a lower zeta potential as compared to those made of pure DDCEDMA alone, which influences their DNA-binding ability. pGFP-N2 plasmid was transferred by cationic liposomes formed from the above cationic lipids into Hela and Hep-2 cells, and the transfection efficiency of some of cationic liposomes was superior or parallel to that of two commercial transfection agents, Lipofectamine2000 and DOTAP. Combined with the results of the agarose gel electrophoresis and transfection experiment, the DNA-binding ability of cationic lipids was too strong to release DNA from complex in the transfection, which could lead to relative low transfection efficiency and high cytotoxicity.

Zhi D; Zhang S; Qureshi F; Zhao Y; Cui S; Wang B; Chen H; Wang Y; Zhao D

2012-06-01

370

Synthesis and biological activity of carbamate-linked cationic lipids for gene delivery in vitro.  

Science.gov (United States)

We have introduced a convenient synthesis method for carbamate-linked cationic lipids. Two cationic lipids N-[1-(2,3-didodecylcarbamoyloxy)propyl]-N,N,N-trimethylammonium iodide (DDCTMA) and N-[1-(2,3-didodecyl carbamoyloxy)propyl]-N-ethyl-N,N-dimethylammonium iodide (DDCEDMA), with identical length of hydrocarbon chains, alternative quaternary ammonium heads, carbamate linkages between hydrocarbon chains and quaternary ammonium heads, were synthesized for liposome-mediated gene delivery. Liposomes composed of DDCEDMA and DOPE in 1:1 ratio exhibited a lower zeta potential as compared to those made of pure DDCEDMA alone, which influences their DNA-binding ability. pGFP-N2 plasmid was transferred by cationic liposomes formed from the above cationic lipids into Hela and Hep-2 cells, and the transfection efficiency of some of cationic liposomes was superior or parallel to that of two commercial transfection agents, Lipofectamine2000 and DOTAP. Combined with the results of the agarose gel electrophoresis and transfection experiment, the DNA-binding ability of cationic lipids was too strong to release DNA from complex in the transfection, which could lead to relative low transfection efficiency and high cytotoxicity. PMID:22542011

Zhi, Defu; Zhang, Shubiao; Qureshi, Farooq; Zhao, Yinan; Cui, Shaohui; Wang, Bing; Chen, Huiying; Wang, Yinhuan; Zhao, Defeng

2012-02-02

371

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

Science.gov (United States)

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

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

2010-03-10

372

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

UK PubMed Central (United Kingdom)

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

Li Y; Li BJ; Ling Y; Miao HJ; Shi YX; Yang XL

2010-03-01

373

Determination of ethyl carbamate in wine by high performance liquid chromatography.  

Science.gov (United States)

Kinetics of pre-column derivatization with 9-xanthydrol for the determination of ethyl carbamate (EC) in wine by a previous high performance liquid chromatographic method with fluorescence detection was studied and further developed. The life-time of the derivatized product and its excitation/absorption spectra were systematically investigated. Using low acidity (pH=2.5 set by phosphate buffers) only 3% of 9-xanthyl ethyl carbamate (XEC) decomposes in ?48h, allowing a prolonged storage time of the derivatized EC conferring more accurate determination for large sample batches. Detection limit of this method is 3?gL(-1), while its average recovery is 98.5±4.9%. Calibration is linear up to 400?gL(-1). The EC content in 33 Hungarian wine samples ranges from 4.9 to 39.9?gL(-1) (average: 17.7?gL(-1), median: 16.7?gL(-1)), while only three of them was slightly over 30?gL(-1) EC, it being the maximum allowed concentration in countries already having legislation. PMID:23790917

Ajtony, Zsolt; Szoboszlai, Norbert; Bencs, László; Viszket, Erna; Mihucz, Victor G

2013-04-18

374

Synergistic pesticide compound containing mepiquat chloride and organophosphorus pesticide  

UK PubMed Central (United Kingdom)

The invention discloses a synergistic pesticide compound containing mepiquat chloride and organophosphorus pesticide the active components of the compound comprise mepiquat chloride and organophosphorus pesticide and the organophosphorus pesticide is chlorpyrifos, phoxim, triazophos or profenofos, wherein the weight ratio of the mepiquat chloride to the organophosphorus pesticide is 1:60 to 10:1. The compound can be applied in preventing lepidoptera or homopteran pests, particularly applied in preventing rice stem borer or plant hopper, and the effect thereof is significantly higher than that of the single dose. Compared with the prior art, the compound can produce higher synergistic effect, overcomes and delays pest medicine resistance, expands the prevention spectrum, has high insecticidal speed, reduces the medication cost and reduces the toxicity.

AIGUO WU; WEI WU; ZHONGYAN WU; ZHONGHUAI XU

375

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

376

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.

M.H. El-Saeid; M.I. Al- Wabel; G. Abdel-Nasser; A.M. Al- Turki; A.G. Al- Ghamdi

2010-01-01

377

Interactions between algae (Selenastrum capricornutum) and pesticides: implications for managing constructed wetlands for pesticide removal.  

UK PubMed Central (United Kingdom)

This laboratory study examined the interactions between an algal species found in wetlands (Selenastrum capricornutum) and two agricultural pesticides (atrazine and lindane). Pesticide additions had a positive effect on the chlorophyll a concentrations of the treatments. The presence of algae decreased the aqueous persistence of both pesticides. It is speculated that the algae either provided sites for pesticide sorption or facilitated pesticide degradation.

Friesen-Pankratz B; Doebel C; Farenhorst A; Goldsborough LG

2003-03-01

378

Choice of pesticide fate models  

International Nuclear Information System (INIS)

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

2006-01-01

379

Prepn of etofenprox as pesticide  

UK PubMed Central (United Kingdom)

The present invention belongs to the field of pesticide technology. The preparation of etofenprox as pesticide uses p-tert-butyl phenol as initial material and includes four reaction steps of acetylating, chlorination, oxyethylation, etc. in the presence of catalyst. The present invention has mild reaction condition, low material cost and simple operation and is suitable for industrial production.

TANG YANSEN; TU HAILAN; SHEN XINGHUAN

380

Pesticide Residue Monitoring Program 2000  

Science.gov (United States)

... (2)Pesticide Analytical Manual Volume I (3rd Ed ... Vegetable oil, refined, 1, 100.0, 0.0, Spices & condiments & flavors, 8, 37.5, 0.0, ... Olives, 10, 100.0, 0.0 ... More results from www.fda.gov/Food/FoodborneIllnessContaminants/Pesticides

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