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1

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

EPA Science Inventory

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

2

A test house study of pesticides and pesticide degradation products following an indoor application.  

PubMed

Preexisting pesticide degradates are a concern for pesticide biomonitoring studies as exposure to them may result in overestimation of pesticide exposure. The purpose of this research was to determine whether there was significant formation and movement, of pesticide degradates over a 5-week period in a controlled indoor setting after insecticide application. Movement of the pesticides during the study was also evaluated. In a simulated crack and crevice application, commercially available formulations of fipronil, propoxur, cis/trans-permethrin, and cypermethrin were applied to a series of wooden slats affixed to the wall in one room of an unoccupied test house. Floor surface samples were collected through 35 days post-application. Concentrations of the pesticides and the following degradates were determined: 2-iso-propoxyphenol, cis/trans 3-(2,2-dichlorovinyl)-3-3-dimethyl-(1-cyclopropane) carboxylic acid, 3-phenoxybenzoic acid, fipronil sulfone, fipronil sulfide, and fipronil desulfinyl. Deltamethrin, which had never been applied, and chlorpyrifos, which had been applied several years earlier, and their degradation products, cis-3-(2,2-dibromovinyl)-2,2-dimethylcyclopropane-1-carboxylic acid, and, 3,5,6-trichloro-2-pyridinol, respectively, were also measured. Propoxur was the only insecticide with mass movement away from the application site. There was no measurable formation or movement of the degradates. However, all degradates were present at low levels in the formulated product. These results indicate longitudinal repetitive sampling of indoor degradate levels during short-term studies, is unnecessary. PMID:24387593

Starr, J M; Gemma, A A; Graham, S E; Stout, D M

2014-08-01

3

Microbial Degradation of Pesticides.  

National Technical Information Service (NTIS)

Microbial degradation of various organochlorine, organophosphorus and carbamate pesticides by aquatic and soil microorganisms was studied. Bacteria, fungi, and an alga (Cylindrospermum sp.) metabolized DDT to water-soluble products. DDT, DDA, and 2-chloro...

M. Alexander

1977-01-01

4

THERMAL DEGRADATION CHARACTERISTICS OF ENVIRONMENTALLY SENSITIVE PESTICIDE PRODUCTS  

EPA Science Inventory

The thermal decomposition properties of the active ingredient of 16 pesticides have been theoretically examined. xperimental studies on 6 pesticide related materials were also conducted under controlled laboratory testing. xperimental studies of the high-temperature oxidation and...

5

Mechanisms of Pesticide Degradation.  

National Technical Information Service (NTIS)

This research project was initiated with the overall objective of determining (1) the chemical structures of toxic components of toxaphene, (2) to study anaerobic metabolism to degrade toxaphene and other pesticides, and (3) to understand toxic action mec...

F. Matsumura

1978-01-01

6

MECHANISMS OF PESTICIDE DEGRADATION  

EPA Science Inventory

This research project was initiated with the overall objective of determining (1) the chemical structures of toxic components of toxaphene, (2) to study anaerobic metabolism to degrade toxaphene and other pesticides, and (3) to understand toxic action mechanism of chlordimeform. ...

7

Effect of household and industrial processing on the levels of pesticide residues and degradation products in melons.  

PubMed

Two varieties of melons (Cucumis melo) were treated with two fungicides (carbendazim and maneb) and four insecticides (acetamiprid, cyromazin, imazalil and thiamethoxam) to quantify the effect of household processing on the pesticide residues. To ensure sufficiently high levels of residues in flesh and peel, the most concentrated formulations were applied observing good agricultural practice. The peeling step decreased the concentration of pesticide residues for maneb, imazalil and acetamiprid by more than 90%. Cyromazin, carbendazim and thiamethoxam were reduced by approximately 50%. The reduction of the pesticides could not be fully explained by the systemic character of the pesticides. However, the agricultural practices (time of application), solubility and mode of action (systemic versus contact pesticide) of the pesticides could be used to explain the difference in processing factors for the studied pesticides. Degradation products (melamine and ethylenethiourea) were also investigated in this study, but were not detected. PMID:22489844

Bonnechère, A; Hanot, V; Bragard, C; Bedoret, T; van Loco, J

2012-01-01

8

Occurrence of pesticides and some of their degradation products in waters in a Spanish wine region  

NASA Astrophysics Data System (ADS)

SummaryA multi-residual analytical method based on solid phase extraction (SPE) followed by liquid chromatography-electrospray ionisation-mass spectrometry (LC-MS) was developed to monitor pesticides in natural waters. Fifty-eight compounds, including herbicides, fungicides, insecticides and some of their degradation products, were surveyed to evaluate the quality of natural waters throughout the wine-growing region of La Rioja (Rioja DOCa). Ninety-two sampling points were selected, including surface and ground waters that could be affected by agricultural activities covering the region's three sub-areas. Different parameters that may affect the efficiency of the SPE procedure were optimised (sorbent type, elution solvent and sample volume), and matrix-matched standards were used to eliminate the variable matrix effect and ensure good quantification. The developed method allows the determination of target compounds below the level established by the European Union for waters for human use with suitable precision (relative standard deviations lower than 18%) and accuracy (with recoveries over 61%). Forty compounds included in this study (six insecticides, 12 herbicides, 16 fungicides and six degradation products) were detected in one or more samples. The herbicides terbuthylazine, its metabolite desethyl terbuthylazine, fluometuron and ethofumesate and the fungicides pyrimethanil and tebuconazole were the compounds most frequently detected in water samples (present in more than 60% of the samples). Concentrations above 0.1 ?g L-1 were detected for 37 of the compounds studied, and in several cases recorded values of over 18 ?g L-1. The results reveal the presence of pesticides in most of the samples investigated. In 64% of groundwaters and 62% of surface waters, the sum of compounds detected was higher than 0.5 ?g L-1 (the limit established by EU legislation for the sum of all pesticides detected in waters for human use).

Herrero-Hernández, E.; Andrades, M. S.; Álvarez-Martín, A.; Pose-Juan, E.; Rodríguez-Cruz, M. S.; Sánchez-Martín, M. J.

2013-04-01

9

Pesticide degradation in a 'biobed' composting substrate.  

PubMed

Pesticides play an important role in the success of modern farming and food production. However, the release of pesticides to the environment arising from non-approved use, poor practice, illegal operations or misuse is increasingly recognised as contributing to water contamination. Biobeds appear to offer a cost-effective method for treating pesticide-contaminated waste. This study was performed to determine whether biobeds can degrade relatively complex pesticide mixtures when applied repeatedly. A pesticide mixture containing isoproturon, pendimethalin, chlorpyrifos, chlorothalonil, epoxiconazole and dimethoate was incubated in biomix and topsoil at concentrations to simulate pesticide disposal. Although the data suggest that interactions between pesticides are possible, the effects were of less significance in biomix than in topsoil. The same mixture was applied on three occasions at 30-day intervals. Degradation was significantly quicker in biomix than in topsoil. The rate of degradation, however, decreased with each additional treatment, possibly due to the toxicity of the pesticide mixture to the microbial community. Incubations with chlorothalonil and pendimethalin carried out in sterile and non-sterile biomix indicated that degradation, rather than irreversible adsorption to the matrix, was the main mechanism responsible for the reduction in recovered residues. Results from these experiments suggest that biobeds offer a viable means of treating pesticide waste. PMID:12741520

Fogg, Paul; Boxall, Alistair B A; Walker, Allan; Jukes, Andrew A

2003-05-01

10

Microbial Degradation of Pesticides.  

National Technical Information Service (NTIS)

The pathway of degradation of one organophosphorus insecticide, Dichlorvos, was studied in detail. A microbial enrichment containing principally two pseudomonads and a bacillus, when incubated in a salts solution containing a vitamin supplement and 250 mi...

M. Alexander

1981-01-01

11

Enhanced degradation of five organophosphorus pesticides in skimmed milk by lactic acid bacteria and its potential relationship with phosphatase production.  

PubMed

Skimmed milk spiked with five organophosphorus pesticides (OPPs), chlorpyrifos, diazinon, fenitrothion, malathion and methyl parathion, was fermented by ten lactic acid bacteria (LAB) and four strain combinations at 42°C for 24h. OPPs left in the samples at different times were extracted, purified, detected by gas chromatography and calculated for degradation rate constants, based on a first-order reaction model. OPPs degradation was enhanced by the inoculated LAB, resulting in 0.8-225.4% increase in the rate constants. Diazinon and methyl parathion were more stable whereas chlorpyrifos, fenitrothion and malathion were more labile. Lactobacillus brevis 1.0209 showed the strongest acceleration on OPPs degradation while strain combination could bring about a synergy between the strains of lower ability. Phosphatase production of the strains might be one of the key factors responsible for the enhanced OPPs degradation, as the detected phosphatase activities were positively correlated to the measured degradation rate constants of OPPs (r=0.636-0.970, P<0.05). PMID:24996321

Zhang, Ying-Hua; Xu, Di; Liu, Jia-Qi; Zhao, Xin-Huai

2014-12-01

12

Factors influencing degradation of pesticides in soil.  

PubMed

Degradation and sorption of six acidic pesticides (2,4-D, dicamba, fluroxypyr, fluazifop-P, metsulfuron-methyl, and flupyrsulfuron-methyl) and four basic pesticides (metribuzin, terbutryn, pirimicarb, and fenpropimorph) were determined in nine temperate soils. Results were submitted to statistical analyses against a wide range of soil and pesticide properties to (i) identify any commonalities in factors influencing rate of degradation and (ii) determine whether there was any link between sorption and degradation processes for the compounds and soils studied. There were some marked differences between the soils in their ability to degrade the different pesticides. The parameters selected to explain variations in degradation rates depended on the soil-pesticide combination. The lack of consistent behavior renders a global approach to prediction of degradation unrealistic. The soil organic carbon content generally had a positive influence on degradation. The relationship between pH and degradation rates depended on the dominant mode of degradation for each pesticide. There were positive relationships between sorption and rate of degradation for metsulfuron-methyl, pirimicarb, and all acidic pesticides considered together (all P < 0.001) and for dicamba and all bases considered together (P < 0.05). No relationship between these processes was observed for the remaining seven individual pesticides. PMID:17488087

Kah, Melanie; Beulke, Sabine; Brown, Colin D

2007-05-30

13

Detection of pyrethroid pesticides and their environmental degradation products in duplicate diet samples  

EPA Science Inventory

The abstract is for an oral presentation at the Asilomar Conference on Mass Spectrometry: Mass Spectrometry in Environmental Chemistry, Toxicology, and Health. It describes analytical method development and sample results for determination of pyrethroid pesticides and environme...

14

Single and mixture effects of pesticides and a degradation product on fluvial biofilms.  

PubMed

The Morcille River located in the Beaujolais vineyard area (Eastern France) is subjected to strong vine-growing pressure leading to the contamination by a range of herbicides and fungicides of the surrounding freshwater environment. Particularly high concentrations of norflurazon, desmethyl norflurazon and tebuconazole were recorded in spring 2010 at the downstream site of the river. Despite their occurrence in rivers, scarce toxicity data are available for these products, in particular in the case of desmethyl norflurazon (main norflurazon degradation product). Furthermore, the toxicity data are generally available only for single compounds and are issued from single species toxicity tests, leading to a lack of ecological relevance. Consequently, this study was undertaken to evaluate the toxic effects of norflurazon, desmethyl norflurazon and tebuconazole singly and in a ternary mixture on fluvial biofilm. Toxicity tests were performed in microplates for 48 h. Photosynthetic endpoints were measured using pulse amplitude-modulated fluorometry; diatom densities and taxonomic composition were determined. After 48 h of exposure, significant effects on optimal quantum yield (F v/F m) for desmethyl norflurazon and mixture were observed. PMID:24549942

Kim Tiam, Sandra; Libert, Xavier; Morin, Soizic; Gonzalez, Patrice; Feurtet-Mazel, Agnès; Mazzella, Nicolas

2014-06-01

15

Determination of atrazine and degradation products in Luxembourgish drinking water: origin and fate of potential endocrine-disrupting pesticides.  

PubMed

Several pesticides have been hypothesized to act as endocrine-disrupting compounds, exhibiting hormonal activity and perturbing normal physiological functions. Among these, especially s-triazine herbicides have received increased attention. Despite being banned in many countries, including the European Union, atrazine is still the world's most widely used herbicide. Despite its discontinued use, considerable concentrations of atrazine and its degradation products, mainly desethylatrazine (DEA) and deisopropylatrazine (DIA), are still found in the environment, including drinking water sources. The aim of this investigation was to study concentrations of especially s-triazine herbicides and major degradation products in drinking water, including spring water, tap water and bottled water in Luxembourg. Spring water (2007/2008/2009, n?=?69/69/69), tap water (2008/2009, n?=?19/26), and bottled water (2007/2008/2009, n?=?5/13/7) were sampled at locations in Luxembourg and investigated for pesticides by LC-ESI-MS/MS. Atrazine was the predominant triazine, detectable in many spring water locations, tap and bottled water, ranging (mean) from 0-57 (9), 0-44 (4), and 0-4 (1) ng?l(-1), respectively. DEA and DIA in spring water ranged (mean) from 0-120 (19) and 0-27 (3) ng?l(-1), with higher concentrations from agricultural areas and low molar ratios of DEA:atrazine <0.5 and high ratios of atrazine:nitrate suggesting point-source contamination. Levels (mean) of DEA and DIA in tap water were 0-62 (14) and 0-6 (<1) ng?l(-1) and in bottled water 0-11 (2) and 0-7 (2) ng?l(-1). Simazine and other triazines were detected in traces (<5?ng?l(-1)). Thus, the conducted monitoring suggested the presence of low concentrations of s-triazines in raw and finished water, presumably partly due to non-agricultural contamination, with concentrations being below thresholds advocated by the European Union Directive 98/83/EC. PMID:21707270

Bohn, T; Cocco, E; Gourdol, L; Guignard, C; Hoffmann, L

2011-08-01

16

75 FR 4383 - Pesticide Products: Registration Applications  

Federal Register 2010, 2011, 2012, 2013

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

2010-01-27

17

75 FR 3235 - Pesticide Products; Registration Applications  

Federal Register 2010, 2011, 2012, 2013

...as follows to register pesticide products containing active...formulating agricultural pesticide formulations, plant growth, regulators, herbicides, fungicides, seed treatments...and other agricultural pesticide formulations. 2....

2010-01-20

18

Results of analyses of the fungicide Chlorothalonil, its degradation products, and other selected pesticides at 22 surface-water sites in five Southern states, 2003-04  

USGS Publications Warehouse

In accordance with the mission of the U.S. Geological Survey (USGS) Toxic Substances Hydrology Program, a pesticide study was conducted during 2003-04 to determine the occurrence of the fungicide chlorothalonil and its degradation products at 22 surface-water sites in five Southern States. Water-quality samples were collected during the peanut-growing season (June-September) in 2003. During the peanut-growing season in 2004, samples were collected after large storms. An analytical method was developed at the USGS Organic Geochemistry Research Laboratory in Lawrence, Kansas, to measure chlorothalonil and its degradation products by liquid chromatography/mass spectrometry (LC/MS). Chlorothalonil was detected in 4 of the 113 surface-water samples. The primary degradation product of chlorothalonil, 4-hydroxy-chlorothalonil, was detected in 26 of the 113 samples with concentrations ranging from 0.002 to 0.930 microgram per liter. The chlorothalonil degradation products, 1-amide-4-hydroxy-chorothalonil and 1,3-diamide-chlorothalonil, were detected in one water sample each at 0.020 and 0.161 microgram per liter, respectively. The USGS Methods and Research Development Group, Lakewood, Colorado, developed a custom method for chlorothalonil using gas chromatography/mass spectrometry (GC/MS) in an effort to achieve a lower laboratory reporting level (LRL) than the USGS National Water-Quality Laboratory (NWQL) schedule 2060, which analyzes the compound chlorothalonil at a LRL of 0.035 ?g/L. The group succeeded in achieving a lower GC/MS reporting level of 0.01 ?g/L. Chlorothalonil was detected in 5 of 68 water samples analyzed using the custom GC/MS method, whereas chlorothalonil was detected in 2 of 21 water samples analyzed using NWQL schedule 2060. In addition to analysis of chlorothalonil and its degradation products, samples were analyzed using the USGS NWQL schedules 2001 and 2060 for about 114 pesticides and their degradation products. Samples also were analyzed for dissolved organic carbon, suspended sediment, and percentage of silt- and clay-sized particles. Overall, it was found that chlorothalonil was detected only infrequently and at relatively low concentrations. Chlorothalonil's major degradation product, 4-hydroxy-chlorothalonil, was detected most frequently, occurred generally at higher concentrations in water samples than did the parent fungicide, and the data from this study reaffirmed that it is the dominant degradation product of chlorothalonil in the peanut-growing environment.

Scribner, Elisabeth A.; Orlando, James L.; Battaglin, William A.; Sandstrom, Mark; Kuivila, Kathryn M.; Meyer, Michael T.

2006-01-01

19

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

Federal Register 2010, 2011, 2012, 2013

...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

20

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

Federal Register 2010, 2011, 2012, 2013

...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

21

Antimicrobial Pesticide Products  

MedlinePLUS

... infectious microorganisms in hospitals and other health care environments. Antimicrobial pesticides have two major uses: disinfect, sanitize, reduce, or mitigate growth or development of microbiological organisms; protect inanimate objects (for example ...

22

75 FR 24694 - Pesticide Products; Registration Applications  

Federal Register 2010, 2011, 2012, 2013

...received applications to register pesticide products containing an active ingredient...in any previously registered pesticide product. Pursuant to the provisions...3(c)(4) of the Federal Insecticide, Fungicide, and...

2010-05-05

23

Household Products Database: Pesticides  

MedlinePLUS

... Names Types of Products Manufacturers Ingredients About the Database FAQ Product Recalls Help Glossary Contact Us More ... holders. Information is extracted from Consumer Product Information Database ©2001-2013 by DeLima Associates. All rights reserved. ...

24

Illegal Pesticide Products  

MedlinePLUS

... They go by names like Tres Pasitos or Chalk , and they come with a guarantee to kill ... Common Illegal Pest Products mothballs | pet products | insecticidal chalk | " Tres Pasitos " | antibacterial products Illegal naphthalene moth repellent ...

25

Ozonation of chlorophenylurea pesticides in water: reaction monitoring and degradation pathways  

Microsoft Academic Search

The degradation of mono- and dichlorophenylureas under ozone\\/hydrogen peroxide conditions was investigated in order to establish the effect of the structural parameters. The N-dimethyl phenylureas (mono- and dichloro) appear to differ strongly from the corresponding N-methyl N-methoxy analogues in terms of disappearance of the parent pesticide and evolution of the by-products identified by MS and MS-MS. The degradation rate of

L Amir Tahmasseb; S Nélieu; L Kerhoas; J Einhorn

2002-01-01

26

Coexpression of two detoxifying pesticide-degrading enzymes in a genetically engineered bacterium  

Microsoft Academic Search

Degradation of pesticides is usually beneficial, since the reactions that destroy pesticides convert most pesticide residues in the environment to inactive, less toxic, harmless compounds. This paper describes a novel strategy using a coexpression vector for the purpose of developing bacteria that can detoxify different pesticides. The vector pETDuet was designed for coexpression of two target genes simultaneously. The organophosphate

W. S. Lan; J. D. Gu; J. L. Zhang; B. C. Shen; H. Jiang; A. Mulchandani; W. Chen; C. L. Qiao

2006-01-01

27

Pesticide leaching FOCUS scenarios if only dissolved pesticides degrade: re-assessing the importance of soil water flow  

NASA Astrophysics Data System (ADS)

Although the pesticide screening policies assume that both dissolved and adsorbed pesticides are subject to transformation (or degradation), it is debatable whether this assumption is correct. Instead, it has been proposed that only dissolved pesticides may degrade, in line with the consensus on other organic contaminants for which only the dissolved or easily accessible fractions are biodegradable. If only dissolved pesticide fractions can degrade, this has major impacts on the pesticide risk assessment in the EU, which so far assumes all pesticide can degrade, whatever their chemical forms. In particular, if only dissolved pesticide degrades, the sorption process becomes completely irrelevant for the long term leached fraction: both regarding its (non)equilibrium and its (non)linearity assumptions. If sorption as such becomes less important, other processes should become more important for the leached fraction, and water flow as the major driving force is a logical candidate. Indeed, the rate of leaching can be shown to depend significantly on the net precipitation, with some prominent adjustments, if sorption becomes less dominant than in the current pesticide screening approaches. It will be shown that the celerity of leaching depends differently on the water flow, than does the leached fraction (which is crucial for pesticide admission policies). Therefore, a reconsideration of EU pesticide screening and admission policies may be necessary.

Te Brake, B.; van der Zee, S. E. A. T. M.; Verhoef, A.

2009-04-01

28

Production, Distribution, Use and Environmental Impact Potential of Selected Pesticides.  

National Technical Information Service (NTIS)

The production, distribution, use patterns, and potential for environmental impacts of pesticides are described, with emphasis on 25 important pesticides that were selected by applying a priority rating system to 125 major pesticides. Information on envir...

1974-01-01

29

40 CFR 165.63 - Scope of pesticide products included.  

Code of Federal Regulations, 2010 CFR

...2009-07-01 2009-07-01 false Scope of pesticide products included. 165.63 Section 165...ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS PESTICIDE MANAGEMENT AND DISPOSAL Standards for...

2009-07-01

30

40 CFR 165.63 - Scope of pesticide products included.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Scope of pesticide products included. 165.63 Section 165...ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS PESTICIDE MANAGEMENT AND DISPOSAL Standards for...

2010-07-01

31

Pesticide Assessment Guidelines, Subdivision G: Product Performance.  

National Technical Information Service (NTIS)

As a guideline for the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA), Subdivision G provides guidance to the registrant on developing product performance data that the Agency may require to demonstrate the effectiveness of their pesticide pr...

C. Grable S. Duffy T. Ellwanger W. Audia W. Campbell

1982-01-01

32

THE DEGRADATION OF SELECTED PESTICIDES IN SOIL: A REVIEW OF THE PUBLISHED LITERATURE  

EPA Science Inventory

This report contains a literature summary on the degradation of forty-five pesticides in soil. The point of beginning of each literature review is the year of issue of the patent for the particular pesticide. After compilation of the literature data for each pesticide, conclusion...

33

Complementary cooperation between two syntrophic bacteria in pesticide degradation.  

PubMed

Interactions between microbial species, including competition and mutualism, influence the abundance and distribution of the related species. For example, metabolic cooperation among multiple bacteria plays a major role in the maintenance of consortia. This study aims to clarify how two bacterial species coexist in a syntrophic association involving the degradation of the pesticide fenitrothion. To elucidate essential mechanisms for maintaining a syntrophic association, we employed a mathematical model based on an experimental study, because experiment cannot elucidate various conditions for two bacterial coexistence. We isolated fenitrothion-degrading Sphingomonas sp. TFEE and its metabolite of 3-methyl-4-nitrophenol (3M4N)-degrading Burkholderia sp. MN1 from a fenitrothion-treated soil microcosm. Neither bacterium can completely degrade fenitrothion alone, but they can utilize the second intermediate, methylhydroquinone (MHQ). Burkholderia sp. MN1 excretes a portion of MHQ during the degradation of 3M4N, from which Sphingomonas sp. TFEE carries out degradation to obtain carbon and energy. Based on experimental findings, we developed mathematical models that represent the syntrophic association involving the two bacteria. We found that the two bacteria are characterized by the mutualistic degradation of fenitrothion. Dynamics of two bacteria are determined by the degree of cooperation between two bacteria (i.e., supply of 3M4N by Sphingomonas sp. TFEE and excretion of MHQ by Burkholderia sp. MN1) and the initial population sizes. The syntrophic association mediates the coexistence of the two bacteria under the possibility of resource competition for MHQ, and robustly facilitates the maintenance of ecosystem function in terms of degrading xenobiotics. Thus, the mathematical analysis and numerical computations based on the experiment indicate the key mechanisms for coexistence of Sphingomonas sp. TFEE and Burkholderia sp. MN1 in syntrophic association involving fenitrothion degradation. PMID:19038271

Katsuyama, Chie; Nakaoka, Shinji; Takeuchi, Yasuhiro; Tago, Kanako; Hayatsu, Masahito; Kato, Kenji

2009-02-21

34

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

PubMed

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

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

2009-04-01

35

Microbiological degradation of pesticides in yard waste composting.  

PubMed Central

Changes in public opinion and legislation have led to the general recognition that solid waste treatment practices must be changed. Solid-waste disposal by landfill is becoming increasingly expensive and regulated and no longer represents a long-term option in view of limited land space and environmental problems. Yard waste, a significant component of municipal solid waste, has previously not been separated from the municipal solid-waste stream. The treatment of municipal solid waste including yard waste must urgently be addressed because disposal via landfill will be prohibited by legislation. Separation of yard waste from municipal solid waste will be mandated in many localities, thus stressing the importance of scrutinizing current composting practices in treating grass clippings, leaves, and other yard residues. Yard waste poses a potential environmental health problem as a result of the widespread use of pesticides in lawn and tree care and the persistence of the residues of these chemicals in plant tissue. Yard waste containing pesticides may present a problem due to the recalcitrant and toxic nature of the pesticide molecules. Current composting processes are based on various modifications of either window systems or in-vessel systems. Both types of processes are ultimately dependent on microbial bioconversions of organic material to innocuous end products. The critical stage of the composting process is the thermophilic phase. The fate and mechanism of removal of pesticides in composting processes is largely unknown and in need of comprehensive analysis.

Fogarty, A M; Tuovinen, O H

1991-01-01

36

Twofold role of calcined hydrotalcites in the degradation of methyl parathion pesticide  

PubMed Central

Summary Methyl parathion (MP) is a very toxic organophosphate pesticide used as a non-systematic insecticide and acaricide on many corps. As MP and its by-products are highly toxic, they have to be retained to avoid pollution of rivers and lakes. Highly efficient sorbents are hydrotalcites (HTs) (or anionic clays). We have correlated the degradation of an aqueous solution of MP at room temperature, with the basicity of the adsorbing materials. It was found that the metal composition of hydrotalcites determines both the surface electronic properties (basic or acidic) and the sorption capacity. Depending on the basic strength, some calcined hydrotalcites can catalyze the transformation of MP to p-nitrophenol (p-NP) and retain its by-products. Such a process has the advantage of being able to be carried out at room temperature and at the pH of the pesticide solution.

Fetter, Geolar; Villafuerte-Castrejon, Maria Elena; Tejeda-Cruz, Adriana; Bosch, Pedro

2011-01-01

37

[Isolation and identification of degradation bacteria Enterobacter aerogenes for pyrethriods pesticide residues and its degradation characteristics].  

PubMed

By incubation experiment, the bacterial strain labeled as M6R9 was isolated from the tame sludge in water course of Pesticide Factory of Hangzhou, and was identified as Enterobacter aerogenes, which had highly efficient degradation for Bifenthrin, Fenpropathrin and Cypermethrin. By investigating the physiological characteristics of the strain, the results show that the bacterium is a gram-negative aerobe bacilli, size is (0.8-1.9) microm x (0.5-1.0) microm, and is capable of utilizing Bifenthrin, Fenpropathrin and Cypermethrin as sole carbon source. Under the condition of ventilation, (25-30) degrees C, inoculated amount at D(415 nm) 0.2, pH 7.0, pesticide concentration 100 mg x L(-1) and vibrational speed 180 r x min(-1), the degradation efficiencies to Bifenthrin, Fenpropathrin and Cypermethrin are the highest by strain M6R9. Under such condition, in the mixture culture medium with 100 mg x L(-1) Bifenthrin, Fenpropathrin and Cypermethrin, the degradation ratios are 55.74%, 55.11% and 55.96% after culturing 3 d, respectively, the degradation processes are fitted for first-order kinetic equation and the half lives (t(1/2)) are 65.4,70.7 and 68.6 h respectively. The degradation ability of Enterobacter aerogenes M6R9 on Bifenthrin, Fenpropathrin and Cypermethrin is positively correlated to inoculated amount,vibrational speed and ventilation. PMID:19799315

Liao, Min; Zhang, Hai-jun; Xie, Xiao-mei

2009-08-15

38

Degradation of Pesticides on Plant Surfaces and its Prediction - A Case Study on Tea Plant  

Microsoft Academic Search

The degradative kinetics of pesticides on plant surface are characterized by an initial rapid degradation which follows a first-order kinetics, then transferred to a more slower degradative rate. The degradative process mainly consists of photodegradation, evaporation, rainfall elution and growth dilution. The influencing parameters of these processes were investigated by using the tea plant as a case study. The predictive

Chen Zongmao; Wan Haibin

1997-01-01

39

[Spectrum study of organochlorine pesticides after nano TiO2 photocatalytic degradation in AgNO3 medium].  

PubMed

A study on a nano anatase TiO2 production from the hydrolysis of TiCl4 was presented. In the nano TiO2 suspending medium, the photocatalytic behaviors for some organochlorine pesticides including alpha, beta, gamma, delta-BHC, DDT, dieldrin, dicofol and agroceres were compared and studied under UV irradiation in the air. Owing to structural difference of C--Cl in the molecule, the degradation efficiencies for the organochlorine pesticides presented an obvious difference with the order of dicofol>dieldrin> DDT>agroceres and alpha-BHC>gamma-BHC>delta-BHC>beta-BHC. Accordingly, the nano TiO2 material was applied as a photocatalyzer, which catalyzed transformation of organochlorine pesticide to chlorine ion. Nanoparticle of silver chloride with a maximal absorbance at the wavelength of 260 nm were prepared in the surfactant polyvinyl alcohol solution. Organochlorine pesticides could be determined according to the concentration of silver chloride. PMID:18800724

Li, Mei-jin; Qiu, Bin; Guo, Guang-mei; Liu, Mei-hua; Chen, Xi

2008-06-01

40

Genome Shuffling Improves Degradation of the Anthropogenic Pesticide Pentachlorophenol by Sphingobium chlorophenolicum ATCC 39723  

Microsoft Academic Search

Pentachlorophenol (PCP), a highly toxic anthropogenic pesticide, can be mineralized by Sphingobium chlorophenolicum, a gram-negative bacterium isolated from PCP-contaminated soil. However, degradation of PCP is slow and S. chlorophenolicum cannot tolerate high levels of PCP. We have used genome shuffling to improve the degradation of PCP by S. chlorophenolicum. We have obtained several strains that degrade PCP faster and tolerate

MingHua Dai; Shelley D. Copley

2004-01-01

41

ADSORPTION, MOVEMENT, AND BIOLOGICAL DEGRADATION OF LARGE CONCENTRATIONS OF SELECTED PESTICIDES IN SOILS  

EPA Science Inventory

Because of the importance of soil in biologically reducing the quantity and retarding the rate of pollutant movement into groundwater, this laboratory study was initiated to evaluate the adsorption, mobility, and degradation of large concentrations of the pesticide atrazine, meth...

42

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

PubMed

Biopurification systems treating pesticide contaminated water are very efficient, however they operate as a black box. Processes inside the system are not yet characterized. To optimize the performance, knowledge of degradation and retention processes needs to be generated. Therefore, displacement experiments were carried out for four pesticides (isoproturon, bentazone, metalaxyl, linuron) in columns containing different organic mixtures. Bromide, isoproturon and bentazone breakthrough curves (BTCs) were well described using the convection-dispersion equation (CDE) and a first-order degradation kinetic approach. Metalaxyl and linuron BTCs were well described using the CDE model expanded with Monod-type kinetics. Freundlich sorption, first-order degradation and Monod kinetics coefficients were fitted to the BTCs. Fitted values of the distribution coefficient K(f,column) were much lower than those determined from batch experiments. Based on mobility, pesticides were ranked as: bentazone>metalaxyl-isoproturon>linuron. Based on degradability, pesticides were ranked as: linuron>metalaxyl-isoproturon>bentazone. PMID:18952328

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

2009-02-01

43

PHOTOCHEMICAL TRANSFORMATION OF THE DDT AND METHOXYCHLOR DEGRADATION PRODUCTS, DDE AND DMDE, BY SUNLIGHT  

EPA Science Inventory

DDE and DMDE, degradation products of the pesticides DDT and methoxychlor, rapidly undergo an unusual photoisomerization in solution when exposed to sunlight. The isomerization involves the exchange of a vinyl chlorine and an ortho aromatic hydrogen. Other photoproducts identifie...

44

Leaching and degradation of 21 pesticides in a full-scale model biobed.  

PubMed

Filling and cleaning of pesticide sprayers presents a potential risk of pollution of soil and water. Three different solutions for handling sprayers have been suggested: Filling and cleaning in the field, filling and cleaning on hard surfaces with collection of the waste water, and filling and cleaning on a biobed, which is an excavation lined with clay and filled with a mixture of chopped straw, sphagnum and soil with turf on top, and with increased sorption capacity and microbial activity for degradation of the pesticides. In the present study the degradation and leaching of 21 pesticides (5 g of each) was followed in an established full-scale model biobed. Percolate was collected and analysed for pesticide residues, and the biobed material was sampled at three different depths and analysed by liquid chromatography double mass spectrometry (LC-MSMS). During the total study period of 563 days, no traces of 10 out of 21 applied pesticides were detected in the percolate (detection limits between 0.02 and 0.9 microg l(-1)) and three pesticides were only detected once and at concentrations below 2 microg l(-1). During the first 198 days before second application, 14% of the applied herbicide bentazone was detected in the leachate with maximum and mean concentrations of 445 and 172 microg l(-1), respectively. About 2% of the initial mecoprop and fluazifop dose was detected in the percolate, with mean concentrations of 23 microg l(-1), while MCPA and dimethoate had mean concentrations of 3.5 and 4.7 microg l(-1), respectively. Leachate concentrations for the remaining pesticides were generally below the detection limit (0.02-0.9 microg l(-1), below 1% of applied). Sorption studies of five pesticides showed that compounds with a low K(d) value appeared in the leachate. After 169 days, all pesticides in the biobed profile were degraded to a level below 50% of the calculated initial dose. Pesticides with K(oc) values above 100 were primarily found in the uppermost 10 cm and degraded slowest due to the low bioavailability. The 11 most degradable pesticides were all degraded such that less than 3% remained in the biobed after 169 days. Following second pesticide application of the biobed, leachate was sampled 215 and 365 days after the treatment. This showed the same pesticides to be leached out and at concentrations comparable to those of the first treatment. The same pesticides as after the first treatment were retained in the biobed. PMID:16815528

Spliid, Niels Henrik; Helweg, Arne; Heinrichson, Kirsten

2006-12-01

45

THE EFFECT OF ORGANOPHOSPHORUS PESTICIDES ON ESTUARINE AMMONIUM OXIDIZERS  

EPA Science Inventory

The effects of seven thiophosphorus pesticides and their degradation products on estuarine ammonium oxidizers were examined. Using an axenic, closed-culture, high cell density assay, the pesticides caused little inhibition of ammonium oxidation. However, the degradation product o...

46

40 CFR 158.2030 - Biochemical pesticides product chemistry data requirements table.  

Code of Federal Regulations, 2010 CFR

...biochemical pesticides product chemistry. The test notes are shown...Biochemical Pesticides Product Chemistry Data Requirements Guideline...biochemical pesticides product chemistry and are referenced in the...µm. 16. Required for organic chemicals unless they...

2009-07-01

47

40 CFR 158.2030 - Biochemical pesticides product chemistry data requirements table.  

Code of Federal Regulations, 2013 CFR

...biochemical pesticides product chemistry. The test notes are shown...Biochemical Pesticides Product Chemistry Data Requirements Guideline...biochemical pesticides product chemistry and are referenced in the...µm. 16. Required for organic chemicals unless they...

2013-07-01

48

40 CFR 158.2030 - Biochemical pesticides product chemistry data requirements table.  

Code of Federal Regulations, 2010 CFR

...biochemical pesticides product chemistry. The test notes are shown...Biochemical Pesticides Product Chemistry Data Requirements Guideline...biochemical pesticides product chemistry and are referenced in the...µm. 16. Required for organic chemicals unless they...

2010-07-01

49

40 CFR 158.2081 - Experimental use permit biochemical pesticides product chemistry data requirements table.  

Code of Federal Regulations, 2010 CFR

...biochemical pesticides product chemistry. The test notes are shown...Biochemical Pesticides Product Chemistry Data Requirements Guideline...biochemical pesticides product chemistry and are referenced in the...µm. 16. Required for organic chemicals unless they...

2009-07-01

50

40 CFR 158.2081 - Experimental use permit biochemical pesticides product chemistry data requirements table.  

Code of Federal Regulations, 2013 CFR

...biochemical pesticides product chemistry. The test notes are shown...Biochemical Pesticides Product Chemistry Data Requirements Guideline...biochemical pesticides product chemistry and are referenced in the...µm. 16. Required for organic chemicals unless they...

2013-07-01

51

40 CFR 158.2081 - Experimental use permit biochemical pesticides product chemistry data requirements table.  

Code of Federal Regulations, 2010 CFR

...biochemical pesticides product chemistry. The test notes are shown...Biochemical Pesticides Product Chemistry Data Requirements Guideline...biochemical pesticides product chemistry and are referenced in the...µm. 16. Required for organic chemicals unless they...

2010-07-01

52

Effects of halving pesticide use on wheat production  

PubMed Central

Pesticides pose serious threats to both human health and the environment. In Europe, farmers are encouraged to reduce their use, and in France a recent environmental policy fixed a target of halving the pesticide use by 2018. Organic and integrated cropping systems have been proposed as possible solutions for reducing pesticide use, but the effect of reducing pesticide use on crop yield remains unclear. Here we use a set of cropping system experiments to quantify the yield losses resulting from a reduction of pesticide use for winter wheat in France. Our estimated yield losses resulting from a 50% reduction in pesticide use ranged from 5 to 13% of the yield obtained with the current pesticide use. At the scale of the whole country, these losses would decrease the French wheat production by about 2 to 3 millions of tons, which represent about 15% of the French wheat export.

Hossard, L.; Philibert, A.; Bertrand, M.; Colnenne-David, C.; Debaeke, P.; Munier-Jolain, N.; Jeuffroy, M. H.; Richard, G.; Makowski, D.

2014-01-01

53

Effects of halving pesticide use on wheat production  

NASA Astrophysics Data System (ADS)

Pesticides pose serious threats to both human health and the environment. In Europe, farmers are encouraged to reduce their use, and in France a recent environmental policy fixed a target of halving the pesticide use by 2018. Organic and integrated cropping systems have been proposed as possible solutions for reducing pesticide use, but the effect of reducing pesticide use on crop yield remains unclear. Here we use a set of cropping system experiments to quantify the yield losses resulting from a reduction of pesticide use for winter wheat in France. Our estimated yield losses resulting from a 50% reduction in pesticide use ranged from 5 to 13% of the yield obtained with the current pesticide use. At the scale of the whole country, these losses would decrease the French wheat production by about 2 to 3 millions of tons, which represent about 15% of the French wheat export.

Hossard, L.; Philibert, A.; Bertrand, M.; Colnenne-David, C.; Debaeke, P.; Munier-Jolain, N.; Jeuffroy, M. H.; Richard, G.; Makowski, D.

2014-03-01

54

Degradation of organochlorine pesticides by meat starter in liquid media and fermented sausage.  

PubMed

The effect of meat starter on the degradation of DDT and lindane was investigated. The insignificant role of Lactobacillus plantarum in degrading p,p'-DDT and lindane presented in tryptone soya broth (TSB) and mineral salt medium (MSM) with or without 120 ppm nitrite was observed.The degradation of DDT and lindane by Micrococcus varians in TSB and MSM with or without nitrite were studied. The results indicated that DDT or lindane were degraded during the incubation period. The reduction in DDT at the end of the incubation period (15 days) was about 24.1 and 32.5% in TSB and MSM without nitrite, respectively. Corresponding values in the same media with nitrite were 37.5 and 46.4%. Regarding the reduction in lindane, it was recorded as 27.9 and 40.0% in TSB and MSM without nitrite, respectively and 38.4 and 48.4% in the same media with nitrite. The results indicated that culture media M. varians metabolized DDT mainly to DDD and lindane mainly to 2,4-, 2,5-, 2,6- and 3,4-dichlorophenol; 2,3,4- and 2,3,5-trichlorophenol; hexachlorobenzene; and pentachlorophenol. The effect of pesticides on the growth rate of meat starter was also investigated. The addition of DDT or lindane resulted in a slight decrease in counts of the strains during the initial incubation in TSB or MSM. Then the microorganisms recovered and began to grow logarithmically, but not as well as in a normal situation. The effect of fermentation stage by meat starter on DDT and lindane in fermented sausage was recorded. The results indicated that during the 72 h of fermentation, the reduction was 10 and 18% of DDT and lindane, respectively. These results confirmed that the fermentation process in meat products reduced pesticide residues and these reductions were due to the activity of meat starter. PMID:11731034

Abou-Arab, A A K

2002-01-01

55

78 FR 10167 - Pesticide Products; Registration Applications for a New Active Ingredient  

Federal Register 2010, 2011, 2012, 2013

...has received applications to register pesticide products containing an active ingredient not included in any currently registered pesticide products. Pursuant to the Federal Insecticide, Fungicide, and Rodenticide Act...

2013-02-13

56

Pesticide Analysis of Bee and Bee Product Samples  

Microsoft Academic Search

Bee products possess therapeutic properties and are the source of many essential trace elements, which is why they are regarded as valuable food products. Honey bees may bring to the hive numerous contaminants deposited on the plants they visit, including pesticide without xenobiotics. The large-scale application of pesticides in agriculture and horticulture can lead to mass mortality among bees, and

?aneta Barga?ska; Jacek Namie?nik

2010-01-01

57

75 FR 61750 - Chloroneb; Product Cancellation Order for Certain Pesticide Registrations  

Federal Register 2010, 2011, 2012, 2013

...Order for Certain Pesticide Registrations AGENCY...cancellation order for products containing the pesticide chloroneb, pursuant...of the Federal Insecticide, Fungicide, and...are not the last products containing this pesticide registered...

2010-10-06

58

ABIOTIC PROCESSES IN THE DEGRADATION OF PESTICIDES IN NATURAL WATERS  

EPA Science Inventory

Pesticides and other trace micropollutants released to the aquatic environment are subject to hydrolysis, oxidation-reduction, and photodecomposition. Kinetic treatments of hydrolysis and direct photolysis processes have been successful in allowing accurate extrapolation of labor...

59

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

PubMed

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

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

2001-01-01

60

Combining chemical and isotopic measurements to estimate pesticide degradation rates in a fractured-rock aquifer  

NASA Astrophysics Data System (ADS)

Encouraged by new regulatory requirements for pesticide registration and authorization, the transport and environmental fate of these compounds in the different environmental compartments has been studied extensively. Degradation rates vary widely depending on hydraulic and chemical characteristics, with the strongest degradation usually occuring in the topsoil. Nonetheless, significant pesticide attenuation may still take place during transport in the aquifer, since residence times are generally much longer than in the soil. Ideally, pesticide transformation in the aquifer needs to be determined under real field conditions. Mass balance calculations however are complicated by the fact that the initial pesticide mass leached from the soil is often not known precisely enough. In this study, isotopic and classical pesticide concentration measurements were combined with groundwater dating techniques to assess the degradation rate of atrazine and its metabolite desethylatrazine in a fractured sandstone. The mass balance problem was solved by introducing the desethylatrazine to atrazine ratio, a relative measure which was used to quantify the advancement of atrazine degradation with increasing transport time in the subsurface. The extent of transformation of the parent compound was finally estimated from the shift in the isotopic signal between soil application and the outlet of the groundwater system.

Farlin, Julien; Gallé, Tom; Bayerle, Michael; Pittois, Denis; El-Khabbaz, Hassanya; Schreglmann, Kathrin; Höche, Martina; Elsner, Martin

2013-04-01

61

Pesticides.  

ERIC Educational Resources Information Center

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

Sherma, Joseph

1989-01-01

62

Draft Genome Sequence of the Methyl Parathion (Pesticide) Degrading Bacterium Pseudomonas spp. MR3.  

PubMed

Pseudomonas spp. MR3 was isolated from the surrounding soil of pesticide manufacturing industries of Ankleshwar, Gujarat. Under laboratory conditions these microbes were able to degrade up to 500 ppm of methyl parathion within 72 h. Genome sequencing of Pseudomonas spp. MR3 was carried out inIon Torrent (PGM), next generation sequencer. The data obtained revealed 1,268 contigs with genome size of 2.99 Mb and G + C content of 60.9 %. The draft genome sequence of strain MR3 will be helpful in studying the genetic pathways involved in the degradation of several pesticides. PMID:24426179

Parakhia, Manoj V; Tomar, Rukam S; Vadukia, Megha R; Malviya, Bipin J; Rathod, Visha M; Thakkar, Jalpa R; Parmar, Kinjal J; Dhingani, Rashmin M; Golakiya, B A

2014-03-01

63

40 CFR 165.65 - Registrants who distribute or sell pesticide products in refillable containers.  

Code of Federal Regulations, 2010 CFR

...2009-07-01 false Registrants who distribute or sell pesticide products in refillable containers. 165.65...ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS PESTICIDE MANAGEMENT AND DISPOSAL Standards for...

2009-07-01

64

40 CFR 165.65 - Registrants who distribute or sell pesticide products in refillable containers.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 false Registrants who distribute or sell pesticide products in refillable containers. 165.65...ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS PESTICIDE MANAGEMENT AND DISPOSAL Standards for...

2010-07-01

65

40 CFR 165.67 - Registrants who distribute or sell pesticide products to refillers for repackaging.  

Code of Federal Regulations, 2010 CFR

...2009-07-01 false Registrants who distribute or sell pesticide products to refillers for repackaging. 165...ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS PESTICIDE MANAGEMENT AND DISPOSAL Standards for...

2009-07-01

66

ORGANOPHOSPHATE PESTICIDE DEGRADATION UNDER DRINKING WATER TREATMENT CONDITIONS  

EPA Science Inventory

Chlorpyrifos (CP) was used as a model compound to develop experimental methods and prototype modeling tools to forecast the fate of organophosphate (OP) pesticides under drinking water treatment conditions. CP was found to rapidly oxidize to chlorpyrifos oxon (CPO) in the presen...

67

ORGANOPHOSPHATE PESTICIDE DEGRADATION UNDER DRINKING WATER TREATMENT CONDITIONS  

EPA Science Inventory

The Food Quality Protection Act (FQPA) of 1996 requires that all tolerances for pesticide chemical residuals in or on food be considered for anticipated exposure. Drinking water is considered a potential pathway for dietary exposure and there is reliable monitoring data for the ...

68

Transport and degradation of pesticides in a biopurification system under variable flux, Part I: a microcosm study.  

PubMed

The efficiency of a biopurification system, developed to treat pesticide contaminated water, is to a large extent determined by the chemical and hydraulic load. Insight into the behaviour of pesticides under different fluxes is necessary. The behaviour of metalaxyl, bentazone, linuron, isoproturon and metamitron was studied under three different fluxes with or without the presence of pesticide-primed soil in column experiments. Due to the time-dependent sorption process, retention of the pesticides with intermediate mobility was significantly influenced by the flux. The higher the flux, the slower pesticides will be sorbed, which resulted in a lower retention. Degradation of the intermediate mobile pesticides was also submissive to variations in flux. An increase in flux, led to a decrease in retention, which in turn decreased the opportunity time for biodegradation. Finally, the presence of pesticide-primed soil was only beneficial for the degradation of metalaxyl. PMID:20696513

De Wilde, Tineke; Spanoghe, Pieter; Ryckeboer, Jaak; Jaeken, Peter; Springael, Dirk

2010-10-01

69

Prioritization of pesticide environmental transformation products in drinking water supplies.  

PubMed

Receiving waters within catchments may be exposed to many different transformation products following the application of pesticides. As environmental waters are abstracted for drinking water treatment these compounds may pose a risk to human health. This paper describes a prioritization approach for identifying the most important transformation products in drinking water sources. The approach can be applied to different geographical areas that have suitable pesticide usage data. The risk based approach incorporates data on pesticide usage and toxicity as well as transformation product formation, mobility, and persistence. The application of the approach is illustrated for two geographical areas that have good quality pesticide usage data: Great Britain and California. The transformation products with the highest risk index and a complete experimentally derived data set for Great Britain were 3,5,6-trichloro-2-pyridinol, thifensulfuron acid, and kresoxim-methyl acid and for California were carbendazim, aldicarb sulfoxide, and RP30228. PMID:17180979

Sinclair, Chris J; Boxall, Alistair B A; Parsons, Simon A; Thomas, Miles R

2006-12-01

70

40 CFR 165.23 - Scope of pesticide products included.  

Code of Federal Regulations, 2010 CFR

...premises and equipment; human drinking water systems; materials preservatives; industrial processes and water systems; antifouling coatings; wood preservatives; or swimming pools. (3) The pesticide product is not a hazardous waste as set out...

2010-07-01

71

40 CFR 165.23 - Scope of pesticide products included.  

Code of Federal Regulations, 2010 CFR

...premises and equipment; human drinking water systems; materials preservatives; industrial processes and water systems; antifouling coatings; wood preservatives; or swimming pools. (3) The pesticide product is not a hazardous waste as set out...

2009-07-01

72

40 CFR 165.43 - Scope of pesticide products included.  

Code of Federal Regulations, 2010 CFR

...caused by bacteria, viruses, fungi, protozoa, algae, or slime; and (B) In the intended use is subject to a tolerance...caused by bacteria, viruses, fungi, protozoa, algae, or slime. (2) The labeling of the pesticide product includes...

2010-07-01

73

40 CFR 165.43 - Scope of pesticide products included.  

Code of Federal Regulations, 2010 CFR

...caused by bacteria, viruses, fungi, protozoa, algae, or slime; and (B) In the intended use is subject to a tolerance...caused by bacteria, viruses, fungi, protozoa, algae, or slime. (2) The labeling of the pesticide product includes...

2009-07-01

74

ANALYSIS OF THE FLUX OF AN ENDOCRINE DISRUPTING DICARBOXIMIDE AND ITS DEGRADATION PRODUCTS FROM THE SOIL TO THE LOWER TROPOSPHERE  

EPA Science Inventory

A method for measuring the atmospheric flux of the antiandrogenic dicarboxirnide, vinclozolin, and its degradation products was investigated. A nitric oxide laboratory chamber was modified to measure the flux of semi-volatile compounds. Pesticide application systems and soil in...

75

The Effect of Operational Parameters on the Photocatalytic Degradation of Pesticide  

Microsoft Academic Search

The photocatalytic degradation of Cartap Hydrochloride, a synthetic pesticide, has been investigated over coated TiO2 photocatalysts irradiated with a ultraviolet (UV) light. The effect of operational parameters, i.e., Cartap Hydrochloride concentration, reaction time, light intensity and additive on the degradation rate of aqueous solution of Cartap Hydrochloride has been examined. Results show that the employment of efficient photocatalysts and the

Euiso Choi; Il-Hyoung Cho; Jaehong Park

2004-01-01

76

In Vitro Pesticide Degradation in Turfgrass Soil Incubated under Open and Sealed Conditions  

Microsoft Academic Search

and flutolanil), insecticides (diazinon and fenitrothion), and herbicides (asulam, simazine, triclopyr, dithiopyr, Degradation of selected pesticides was conducted in a turfgrass MCPP, and terbutol) appeared in the drainage water soil from a golf course under open (i.e., allowing gas exchange with atmosphere) and sealed systems. The time required for 50% of the that originates mainly from leaching and runoff water

Toshinari Suzuki; Kumiko Yaguchi; Sukeji Suzuki; Tetsuya Suga

2001-01-01

77

75 FR 74713 - Product Cancellation Order for Certain Pesticide Registrations; Correction  

Federal Register 2010, 2011, 2012, 2013

...document is being issued to rescind the cancellation of Sergeant's Pet Care Products' pesticide product, EPA Reg. No. 2517-79...notice do? This notice rescinds the cancellation of Sergeant's Pet Care Products' pesticide product, EPA Reg. No....

2010-12-01

78

Heterogeneous Photocatalytic Degradation of Selected Organophosphate Pesticides: A Review  

Microsoft Academic Search

This review is an attempt to summarize the research carried out on heterogeneous photocatalytic treatment of selected organophosphates present invariably in shallow and ground water supplies. The basic principle of semiconductor mediated photocatalytic process, experimental conditions used, optimization of the parameters affecting the efficiency and degradation mechanism has been explained. The kinetics of organophosphate degradation and the analytical techniques for

Dhiraj Sud; Paramjeet Kaur

2011-01-01

79

Bioremediation of pesticide contaminated water using an organophosphate degrading enzyme immobilized on nonwoven polyester textiles.  

PubMed

Bioremediation using enzymes has become an attractive approach for removing hazardous chemicals such as organophosphate pesticides from the environment. Enzymes immobilized on solid carriers are particularly suited for such applications. In this study, the organophosphate degrading enzyme A (OpdA) was covalently immobilized on highly porous nonwoven polyester fabrics for organophosphate pesticide degradation. The fabrics were first activated with ethylenediamine to introduce free amine groups, and the enzyme was then attached using the bifunctional crosslinker glutaraldehyde. The immobilization only slightly increased the Km (for methyl parathion, MP), broadened the pH profile such that the enzyme had significant activity at acidic pH, and enhanced the stability of the enzyme. The OpdA-functionalized fabrics could be stored in a phosphate buffer or in the dry state at 4°C for at least 4 weeks without a large loss of activity. When used in batch mode, the functionalized textiles could degrade 20 ?M MP in un-buffered water at liquor to fabric ratios as high as 5000:1 within 2h, and could be used repeatedly. The fabrics could also be made into columns for continuous pesticide degradation. The columns were able to degrade 50 ?M MP at high flow rates, and could be used repeatedly over 2 months. These results demonstrate that OpdA immobilized on nonwoven polyester fabrics is useful in environmental remediation of organophosphate compounds. PMID:24267566

Gao, Yuan; Truong, Yen Bach; Cacioli, Paul; Butler, Phil; Kyratzis, Ilias Louis

2014-01-10

80

40 CFR 158.2030 - Biochemical pesticides product chemistry data requirements table.  

Code of Federal Regulations, 2012 CFR

...false Biochemical pesticides product chemistry data requirements table. 158.2030...2030 Biochemical pesticides product chemistry data requirements table. (a) General...use this table to determine the product chemistry data requirements for a...

2012-07-01

81

40 CFR 158.2081 - Experimental use permit biochemical pesticides product chemistry data requirements table.  

Code of Federal Regulations, 2012 CFR

...permit biochemical pesticides product chemistry data requirements table. 158.2081...permit biochemical pesticides product chemistry data requirements table. (a) General...use this table to determine the product chemistry data requirements for a...

2012-07-01

82

A sensitivity analysis of adsorption and degradation parameters in the modeling of pesticide transport in soils  

NASA Astrophysics Data System (ADS)

The increasing use of deterministic models in predicting the movement of pesticides in soils, has focused attention on the evaluation of major parameters which represent attenuation factors of organics in the subsurface. These parameters are the degradation rate constant and the adsorption constant for the pesticide. In view of the large in situ variability of these parameters and of the difficulty in obtaining accurate field data, there is a high degree of uncertainty associated with the results obtained from deterministic models. A sensitivity analysis is performed here to quantify the impact of such variation in each of these input parameters on the output results of an unsaturated zone transport model (PRZM). Results show that variations in these parameters about their respective mean values greatly affect the predicted concentration distributions, obtained after three years, of the pesticide aldicarb in all the soil profile. A 15-22% variation in the degradation constant, or a 24% variation in the adsorption constant, lead to a 100% uncertainty in the various simulation results defined as the cumulative quantity of aldicarb or the dissolved aldicarb concentration leached below the root zone (or the unsaturated zone) of the soil. Such a deterministic model presents a high degree of sensitivity to these input parameters. Accurate field data are then needed to obtain reliable model results in predicting pesticide movement inthe unsaturated zone.

Villeneuve, Jean-Pierre; Lafrance, Pierre; Banton, Oliver; Frechette, Pierre; Robert, Claude

1988-09-01

83

Aqueous Pesticide Degradation by Ozonation and Ozone-Based Advanced Oxidation Processes: A Review (Part I)  

Microsoft Academic Search

Pesticide pollution of surface water and groundwater has been recognized as a major problem in many countries because of their persistence in aquatic environment and potential adverse health effects. Among various water and wastewater treatment options, ozonation and ozone-based advanced oxidation processes, such as ozone\\/hydrogen peroxide, ozone\\/ultraviolet irradiation, and ozone\\/hydrogen peroxide\\/ultraviolet irradiation, are likely key technologies for degrading and detoxifying

Keisuke Ikehata; Mohamed Gamal El-Din

2005-01-01

84

Biodegradation of pesticides in soil: Rapid induction of carbamate degrading factors after carbofuran treatment  

Microsoft Academic Search

Degradation rates of carbofuran were greatly increased by a single 10 ppm carbofuran pre?treatment of a sandy loam soil with no previous history of pesticide use. Thorough mixing was required to homogeneously distribute the active agent(s). Numbers of bacteria and fungi were not affected by the pre?treatment, but the drastic reduction in activity produced by heat sterilization, freezing or drying

C. R. Harris; R. A. Chapman; C. M. Tu

1984-01-01

85

Estimation of pesticide and transformation product export pathways in a headwater catchment  

NASA Astrophysics Data System (ADS)

Following their application, pesticide residues are exported towards rivers along several hydrological pathways in agricultural areas. The importance of each pathway is influenced by the substances' physico-chemical characteristics, mainly sorption and degradation. Incomplete mineralization results in the formation of transformation products (TPs) which have generally different environmental fate characteristics than their parent compounds (PCs). Therefore, the export pathways of pesticides and their transformation products towards rivers may also be different. In order to investigate this hypothesis, we extended a distributed process-based hydrological model (ZIN-AgriTra) by the environmental fate of pesticides and their TPs. The process-based nature of the model allowed for an analysis of PC and TP export pathways including overland flow, lateral preferential flow in soils and soil water flow to tile drains. The model was applied to a Swiss headwater catchment using three pesticides and their TPs as test substances. It was successfully calibrated to three sampling stations in the catchment. At the end of the simulated three-months period, most of the applied pesticides were either fully mineralized or incompletely transformed. Less than 2% of each pesticide was exported to the river as PC or TP. Although all three pesticides could be classified as slightly mobile they remained in the top soil layer during the whole period, whereas the more mobile TPs were additionally leached through the soil towards tile drains. Accordingly, PCs were exported largely by surface runoff, while a larger share of TPs was exported via tile drains. Additionally, the delayed formation and degradation of TPs led to an export under different hydrological conditions resulting in an increased subsurface export of TPs towards the end of the simulation period. A consequence of the different export pathways of PCs and TPs could be shown by an assessment of critical source areas (CSA) in the study catchment: CSA for PCs were restricted to small areas whereas CSA for TPs were more equally distributed in the catchment. Our study demonstrates that PCs and their TPs have generally different export pathways in catchments because of their different physico-chemical properties and the delayed formation of TPs. We suggest that these results should be considered in risk assessment of pesticide residues export to adjacent rivers and that catchment scale models should be extended to include both PCs and TPs.

Gassmann, Matthias; Olsson, Oliver; Stamm, Christian; Weiler, Markus; Lange, Jens; Kümmerer, Klaus

2014-05-01

86

Effect of biochar and digestate on microbial respiration and pesticide degradation  

NASA Astrophysics Data System (ADS)

To overcome the problem of on farm point sources of pollution stemming from improper handling, spillages, and leakages of pesticides during filling and cleaning of spraying equipment, environmental friendly and low cost technology filter systems are currently under development. Based on a laboratory screening approach, where different biomixtures (soil, with biochar and/or digestate) are tested a full scale outdoor system will be developed. Therefore, different fundamental processes like pesticide mineralization, metabolization, sorption-desorption, and transport behavior of three radiolabelled pesticides (Bentazone, Boscalid and Pyrimethanil) will be investigated. Biochar and digestate mixtures with two contrasting soils (sandy and silt loam) had been used as a novel biofilter material for respiration study instead of conventional soil and straw mixtures. To analyze the pesticide degradation potential and to gain information about the temporal evolution of the degradation process of the biochar and digestate soil mixtures microbial respiration was measured over the course of three month. As expected, digestate acts as an easily available C-source leading to highest release of CO2 compared to other biomixtures used. In contrast, the addition of even small amounts (1 %) of biochar caused a profound suppression in the CO2 release from digestate based mixtures. The exact driving mechanism for this suppression can be manifold likes negative priming or chemisorption of CO2 on biochar or NH3 toxicity induced by the large amount of digestate applied in the experiment (30 %) or can be combination of all effects. Surprisingly, a repeated experiment with same but aged digestate did not show such negative priming. On the other hand, the fate of applied organic contaminants to biomixtures depends on several factors like soil properties and climatic conditions as well as biological degradation. To analyze the degradation potential of the different soil/amendment mixtures a degradation study was performed to determine the effects of biochar and digestate in different mixing rates on the metabolization behavior of the studied pesticides, and to identify and quantify the metabolites derived during the degradation process. The results from the 14C Bentazone study indicate that 5 % digestate and 5 % biochar mixture showed highest (nearly~ 15 %) and 1 % biochar lowest rate of mineralization (~1 %), whereby highest microbial activity was measured in the soil/digestate mixture.

Mukherjee, Santanu; Tappe, Wolfgang; Hofmann, Diana; Köppchen, Stephan; Disko, Ulrich; Weihermüller, Lutz; Burauel, Peter; Vereecken, Harry

2014-05-01

87

Input dynamics of pesticide transformation products into surface water  

NASA Astrophysics Data System (ADS)

Some pesticide transformation products have been observed to occur in higher concentrations and more frequently than the parent active pesticide in surface water and groundwater. These products are often more mobile and sometimes more stable than the parent pesticide. If they also represent the major product into which the parent substance is transformed, these transformation products may dominate observed pesticide occurrences in surface water and groundwater. Their potential contribution to the overall risk to the aquatic environment caused by the use of the parent pesticide should therefore not be neglected in chemical risk and water quality assessments. The same is true for transformation products of other compound classes that might reach the soil environment, such as veterinary pharmaceuticals. However, the fate and input pathways of transformation products of soil-applied chemicals into surface water are not yet well understood, which largely prevents their appropriate inclusion into chemical risk and water quality assessments. Here, we studied whether prioritization methods based on available environmental fate data from pesticide registration dossiers in combination with basic fate models could help identify transformation products which can be found in relevant concentrations in surface and groundwater and which should therefore be included into monitoring programs. A three-box steady state model containing air, soil, and surface water compartments was used to predict relative inputs of pesticide transformation products into surface waters based on their physico-chemical and environmental fate properties. The model predictions were compared to monitoring data from a small Swiss river located in an intensely agricultural catchment (90 km2) which was flow-proportionally sampled from May to October 2008 and screened for 74 pesticides as well as 50 corresponding transformation products. Sampling mainly occurred during high discharge, but additional samples during baseflow conditions were also taken. The analytical measurements included solid phase extraction, liquid chromatography and high resolution mass spectrometry (SPE-LC-HR-MS/MS). Quantification was achieved using reference standards and internal standards. Besides the well-known transformation products of triazine and chloroacetanilide herbicides, transformation products of other compound classes such as azoxystrobin acid (from azoxystrobin, strobilurin fungicide), chloridazon-desphenyl and chloridazon-methyl-desphenyl (from chloridazon, pyridazinone herbicide), and metamitron-desamino (from metamitron, triazinone herbicide) were analyzed in surface water. For a selection of widely used pesticides in the catchment, modelled ratios of transformation product versus parent pesticide concentrations were compared to the measured concentration ratios in the river for the application period and for two 2-month periods following application. Concentration ratios agreed within a factor of 10 for all pairs of parent pesticides and transformation products, and for all seasons, with a single exception. The ratio of chloridazon-desphenyl to chloridazon was under-predicted by a factor of approximately 20. The data revealed that chloridazon-desphenyl was also found in elevated concentrations in all baseflow samples, indicating its presence in the groundwater component of the catchment. The same was true for other transformation products (e.g., metamitron-desamino, chloridazon-methly-desphenyl, metolachlor-ESA), but to a lesser degree. Based on baseflow separation of the hydrograph, the concentration ratio estimation model was supplemented with an additional baseflow component. The concentrations in the baseflow component were estimated with a simple leaching relationship that was compared against measured baseflow concentrations and groundwater findings in Switzerland. The final model yielded good agreement for all compounds and is therefore deemed suitable for prioritization of transformation products with a relevant exposure potential. It also clearly indicated the contr

Kern, Susanne; Singer, Heinz; Hollender, Juliane; Schwarzenbach, René P.; Fenner, Kathrin

2010-05-01

88

Titanium dioxide photoinduced degradation of some pesticide/fungicide precursors.  

PubMed

Five-membered nitrogen heterocycles (pyrrole, imidazole and 1,2,4-triazole) have been degraded using titanium dioxide and simulated solar radiation at pH = 8. The degradations followed a simple Langmuir-Hinshelwood mechanism. Accordingly, the adsorption equilibrium constants K of the heterocycles on the titanium dioxide surface and the rate constants k of degradation of the heterocycle-catalyst adduct have been obtained experimentally. While the K values decrease with heterocycle pKa, the k values increase with increasing pKa. Therefore, apparently, the rate constant depends on the availability of the electron pair on nitrogen, but at the same time the electron pair repulsion induced by the negatively charged titanium dioxide surface at pH = 8 causes a reverse effect in the adsorption equilibrium constant. Only in the case of imidazole, where the adsorption equilibrium constant is low enough (K = 0.013 M(-1)), can the rate constant be approximated to a pseudo-first-order rate expression: k(obs) = Kk. In all other cases, k(obs) = Kk/(1 + K(heterocycle)). PMID:17397114

Kuehr, Ivana; Núñez, Oswaldo

2007-05-01

89

76 FR 60023 - Pesticide Products; Receipt of Applications To Register New Uses  

Federal Register 2010, 2011, 2012, 2013

...EPA-HQ-OPP-2011-0005; FRL-8888-5] Pesticide Products; Receipt of Applications To...applications to register new uses for pesticide products containing currently registered...section 3(c) of the Federal Insecticide, Fungicide, and...

2011-09-28

90

75 FR 6386 - Pesticide Products; Registration Applications for a New Active Ingredient Chemical; Demiditraz  

Federal Register 2010, 2011, 2012, 2013

...received applications to register pesticide products containing active ingredients...in any previously registered pesticide products. Pursuant to the provisions...c)(4) of the Federal Insecticide, Fungicide, and...

2010-02-09

91

75 FR 19390 - Cydia Pomonella Granulovirus; Product Cancellation Order for a Pesticide Registration  

Federal Register 2010, 2011, 2012, 2013

...Pomonella Granulovirus; Product Cancellation Order for a Pesticide Registration AGENCY...cancellation order of a product containing the pesticide, Cydia pomonella granulovirus...section 3 of the Federal Insecticide, Fungicide, and...

2010-04-14

92

Photocatalytic degradation of pesticides and bio-molecules in water.  

PubMed

Two approaches are suggested for the acceleration of the photocatalytic oxidation of organic contaminants of water: acceleration by oxidants and photo-enhancement by dyes. These processes were examined with several substances: two widely applied herbicides, bromacil (a uracil) and metribuzin (a triazine), and three proteins, studied as models of biocontaminated waters. The effects of oxygen and hydrogen peroxide indicated two different reaction patterns of photo-oxidation of the herbicides. With metribuzin, oxygen had a pronounced effect on the rate of photo-oxidation, while the influence of hydrogen peroxide was quite moderate; with bromacil, oxygen had a limited effect on the rate of photo-oxidation, which however was considerably enhanced by hydrogen peroxide. Acceleration of the photo-catalytic oxidation of colourless refractory contaminants by photo-excited dye was observed. Both UV and visible light were required for the enhanced decomposition. The mechanism of the reaction seems to involve a combination of oxidation by hydroxyl radicals, via the hole-electron semiconductor route, with subsequent oxidation of photo-intermediates by singlet oxygen formed by dye sensitization. The TiO2-photocatalyzed oxidation of proteins (albumin, ovalbumin and gamma-globulin) showed the susceptibility of proteins to photocleavage and of the amino acids to photocatalytic degradation. Tyrosine was the most sensitive, while the degradation of the aliphatic amino acids Gly and Asp was slow. PMID:12449534

Muszkat, Lea; Feigelson, Leonid; Bir, Lena; Muszkat, Karol A

2002-11-01

93

Pesticide Regulation (PR) Notice 96-6. Notice to Manufacturers, Formulators, Producers and Registrants of Pesticide Products. Pet Pesticide Product Label Statements.  

National Technical Information Service (NTIS)

This notice specifies statements that should be added to the labels of pesticide products which are registered for use on dogs and/or cats. The label statements outlined in this notice will help to ensure that products bear labeling that will reduce the p...

1996-01-01

94

Solar photocatalytic degradation of some hazardous water-soluble pesticides at pilot-plant scale.  

PubMed

The technical feasibility and performance of photocatalytic degradation of six water-soluble pesticides (cymoxanil, methomyl, oxamyl, dimethoate, pyrimethanil and telone) have been studied at pilot-plant scale in two well-defined systems which are of special interest because natural solar UV light can be used: heterogeneous photocatalysis with titanium dioxide and homogeneous photocatalysis by photo-Fenton. TiO(2) photocatalysis tests were performed in a 35L solar pilot plant with three Compound Parabolic Collectors (CPCs) under natural illumination and a 75L solar pilot plant with four CPC units was used for homogeneous photocatalysis tests. The initial pesticide concentration studied was 50 mg L(-1) and the catalyst concentrations employed were 200 mg L(-1) of TiO(2) and 20 mg L(-1) of iron. Both toxicity (Vibrio fischeri, Biofix) and biodegradability (Zahn-Wellens test) of the initial pesticide solutions were also measured. Total disappearance of the parent compounds and nearly complete mineralization were attained with all pesticides tested. Treatment time, hydrogen peroxide consumption and release of heteroatoms are discussed. PMID:16839679

Oller, I; Gernjak, W; Maldonado, M I; Pérez-Estrada, L A; Sánchez-Pérez, J A; Malato, S

2006-12-01

95

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

SciTech Connect

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

Not Available

1992-05-01

96

Transport and degradation of pesticides in a biopurification system under variable flux Part II: A macrocosm study.  

PubMed

Transport of bentazone, isoproturon, linuron, metamitron and metalaxyl were studied under three different flows in macrocosms. The aim was to verify the observations from Part I of the accompanying paper, with an increase in column volume and decrease in chemical and hydraulic load. Very limited breakthrough occurred in the macrocosms for all pesticides, except bentazone, at all flows. From batch degradation experiments, it was observed that the lag time of metamitron and linuron decreased drastically in time for all flows, indicating a growth in the pesticide degrading population. This in contrast to isoproturon and metalaxyl, where an increase in lag time could be observed in time for all flows. From the batch degradation experiments, it could be concluded that the influence of flow on the lag time was minimal and that the inoculation of the pesticide-primed soil had a little surplus value on degradation. PMID:20696511

De Wilde, Tineke; Spanoghe, Pieter; Ryckeboer, Jaak; Jaeken, Peter; Springael, Dirk

2010-10-01

97

78 FR 76612 - Notice of Receipt of Pesticide Products; Registration Applications To Register New Uses  

Federal Register 2010, 2011, 2012, 2013

...www.epa.gov/pesticides/regulating/registration-public-involvement...register new uses for pesticide products containing...241-418 (Prowl H2O Herbicide). Docket ID number...Flazasulfuron. Product type: Herbicide. Proposed use: Tree...Environmental protection, Pesticides and pest....

2013-12-18

98

Photocatalytic degradation of pesticides in pure water and a commercial agricultural solution on TiO2 coated media.  

PubMed

Heterogeneous photocatalysis of pesticides is an effective process for removing pesticides from pure water. With a view to treating real agricultural effluents, this paper deals with the degradation of the chlortoluron and cyproconazole pesticides in pure water and the treatment of commercial solutions by photocatalysis on TiO2 coated media. The process was effective in degrading and mineralizing the pesticides. The changes of the fate of heteroatoms showed that during irradiation of the chlortoluron and cyproconazole, NH4+ and NO3(-) ions were produced. A release of chloride ions was observed from the beginning of the irradiation and stoichiometry was achieved. The photodegradation of chlortoluton and cyproconazole in commercial solutions was studied. For the degradation of chlortoluton in a commercial solution, the mineralization was completely achieved whereas in the case of the commercial cyproconazole solution, the degradation kinetic was lower. These results highlight the fact that the chemical nature of the additives in the commercial pesticide solutions does significantly affect the degradation yield of the target compound by photocatalysis. PMID:17709129

Lhomme, L; Brosillon, S; Wolbert, D

2008-01-01

99

Effects of single pesticides and binary pesticide mixtures on estrone production in H295R cells.  

PubMed

The aim of the present study was to determine whether the human adrenocortical carcinoma cell line H295R can be used as an in vitro test system to investigate the effects of binary pesticide combinations on estrone production as biological endpoint. In the first step ten pesticides selected according to a tiered approach were tested individually. The anilinopyrimidines cyprodinil and pyrimethanil as well as the dicarboximides iprodione and procymidone increased estrone concentration, while the triazoles myclobutanil and tebuconazole as well as the strobilurins azoxystrobin and kresoxim-methyl decreased estrone concentration in the supernatant of H295R cells. The N-methylcarbamate methomyl did not show any effects, and the phthalimide captan reduced estrone concentration unspecifically due to its detrimental impact on cellular viability. When cyprodinil and pyrimethanil, which belong to the same chemical group and increase estrone production, were combined, in most of the cases the overall effect was solely determined by the most potent compound in the mixture (i.e., cyprodinil). When cyprodinil and procymidone, which belong to different chemical groups but increase estrone production, were combined, in most cases an additive effect was observed. When cyprodinil, which increased estrone production, was combined with either myclobutanil or azoxystrobin, which decreased estrone production, the overall effect of the mixture was in most cases either entirely determined by myclobutanil or at least partially modulated by azoxystrobin. In conclusion, H295R cells appear to be an adequate in vitro test system to study the effect of combining two pesticides affecting estrone production. PMID:23708528

Prutner, Wiebke; Nicken, Petra; Haunhorst, Eberhard; Hamscher, Gerd; Steinberg, Pablo

2013-12-01

100

75 FR 8339 - Difenzoquat; Product Cancellation Order for Certain Pesticide Registrations  

Federal Register 2010, 2011, 2012, 2013

...distribution, or use of pesticides. Since others also...copy, at the Office of Pesticide Programs (OPP) Regulatory...Technical AMVAC Chemical Herbicide Corporation...Wild Oat AMVAC Chemical Herbicide Corporation...that a registrant of a pesticide product may at any...

2010-02-24

101

76 FR 17645 - Pesticide Products; Registration Applications  

Federal Register 2010, 2011, 2012, 2013

...product containing the active ingredient aldicarb. Pursuant to the provisions of section...product containing the active ingredient aldicarb. On August 16, 2010, shortly before...Bayer, the only current registrant of aldicarb, concluded a Memorandum of...

2011-03-30

102

76 FR 5805 - Pesticide Products; Registration Applications  

Federal Register 2010, 2011, 2012, 2013

...classification/Use: For use in formulation of emulsion products, paints, building materials...Pasteuria reniformis--Liquid Formulation. Active Ingredient: Nematicide...Pasteuria nishizawae--Liquid Formulation. Active Ingredient:...

2011-02-02

103

76 FR 17644 - Pesticide Product; Registration Application  

Federal Register 2010, 2011, 2012, 2013

...this application does not imply a decision by the Agency on this application. File symbol: 53575-UN. Applicant: Pacific Biocontrol Corporation, 14615 NE., Thirteenth Court, Suite A, Vancouver, WA 98685. Product name: Isomate-DWB. Active...

2011-03-30

104

Characterization of degradation products of mometasone furoate.  

PubMed

Mometasone furoate (MF) is a synthetic glucocorticoid with anti-inflammatory activity, which is used for the treatment of topical skin disorders, allergic rhinitis and treatment of mild to moderate persistent asthma. The focus of this study is to examine the stability of MF in simulated lung fluid (SLF) and to clearly identify the structure of the degradation products of MF by MS and NMR analysis. Mometasone furoate degradation leads to the formation of two products, D1 and D2 with significant pH dependence. The half-lives for the conversion of MF to D1 and subsequent conversion of D1 to D2 at 37 degrees C in SLF were 1.3 and 4.8 h respectively. LC-MS and NMR analysis confirmed that D1 is 9,11-epoxide mometasone furoate while D2 represents a new chemical structure that shows cyclization within the C17-C21 region. The biological activity of these degradation products was assessed in rat lung glucocorticoid receptor binding studies. D1 showed 4 fold greater receptor affinity to glucocorticoid receptors compared to dexamethasone. However, the receptor affinity for D2 was a log order lower than that for dexamethasone. The instability of MF in SLF resulted in two degradation products, one of the degradation products showing glucocorticoid receptor activity, the other representing a new cyclized structure whose pharmacological properties have not been described. The biological significance of these degradation products is unknown. PMID:15212303

Sahasranaman, S; Issar, M; Tóth, G; Horváth, Gy; Hochhaus, G

2004-05-01

105

Photocatalytic degradation of eight pesticides in leaching water by use of ZnO under natural sunlight.  

PubMed

Photodegradation of eight pesticides in leaching water at pilot plant scale using the tandem ZnO/Na(2)S(2)O(8) as photosensitizer/oxidant and compound parabolic collectors under natural sunlight is reported. The pesticides, habitually used on pepper culture and belonging to different chemical groups were azoxyxtrobin, kresoxim-methyl, hexaconazole, tebuconazole, triadimenol, and pyrimethanil (fungicides), primicarb (insecticide), and propyzamide (herbicide). As expected, the influence of the semiconductor used at 150 mg L(-1) on the degradation of pesticides was very significant in all cases. Photocatalytic experiments show that the addition of photosensitizer strongly improves the elimination of pesticides in comparison with photolytic tests; significantly increasing the reaction rates. The use of Na(2)S(2)O(8) implies a significant reduction in treatment time showing a quicker reaction time than ZnO alone. On the contrary, the addition of H(2)O(2) into illuminated ZnO suspensions does not improve the rate of photooxidation. The disappearance of the pesticides followed first-order kinetics according to Langmuir-Hinshelwood model and complete degradation occurs from 60 to 120 min. The disappearance time (DT(75)), referred to the normalized illumination time (t(30 W)) was lower than 3 min in all cases. PMID:19729242

Navarro, S; Fenoll, J; Vela, N; Ruiz, E; Navarro, G

2009-12-30

106

Single-Step Production of a Recyclable Nanobiocatalyst for Organophosphate Pesticides Biodegradation Using Functionalized Bacterial Magnetosomes  

PubMed Central

Enzymes are versatile catalysts in laboratories and on an industrial scale; improving their immobilization would be beneficial to broadening their applicability and ensuring their (re)use. Lipid-coated nano-magnets produced by magnetotactic bacteria are suitable for a universally applicable single-step method of enzyme immobilization. By genetically functionalizing the membrane surrounding these magnetite particles with a phosphohydrolase, we engineered an easy-to-purify, robust and recyclable biocatalyst to degrade ethyl-paraoxon, a commonly used pesticide. For this, we genetically fused the opd gene from Flavobacterium sp. ATCC 27551 encoding a paraoxonase to mamC, an abundant protein of the magnetosome membrane in Magnetospirillum magneticum AMB-1. The MamC protein acts as an anchor for the paraoxonase to the magnetosome surface, thus producing magnetic nanoparticles displaying phosphohydrolase activity. Magnetosomes functionalized with Opd were easily recovered from genetically modified AMB-1 cells: after cellular disruption with a French press, the magnetic nanoparticles are purified using a commercially available magnetic separation system. The catalytic properties of the immobilized Opd were measured on ethyl-paraoxon hydrolysis: they are comparable with the purified enzyme, with Km (and kcat) values of 58 µM (and 178 s?1) and 43 µM (and 314 s?1) for the immobilized and purified enzyme respectively. The Opd, a metalloenzyme requiring a zinc cofactor, is thus properly matured in AMB-1. The recycling of the functionalized magnetosomes was investigated and their catalytic activity proved to be stable over repeated use for pesticide degradation. In this study, we demonstrate the easy production of functionalized magnetic nanoparticles with suitably genetically modified magnetotactic bacteria that are efficient as a reusable nanobiocatalyst for pesticides bioremediation in contaminated effluents.

Ginet, Nicolas; Pardoux, Romain; Adryanczyk, Geraldine; Garcia, Daniel; Brutesco, Catherine; Pignol, David

2011-01-01

107

78 FR 4073 - Labeling of Pesticide Products and Devices for Export; Clarification of Requirements  

Federal Register 2010, 2011, 2012, 2013

...of Pesticide Products and Devices for Export; Clarification of Requirements AGENCY...products and devices intended solely for export. Specifically, EPA is restructuring...those products are intended solely for export at the time of such transfer. EPA...

2013-01-18

108

75 FR 57019 - Pesticide Product Registrations; Conditional Approval  

Federal Register 2010, 2011, 2012, 2013

...identification (ID) number EPA-HQ-OPP-2009-0184...at the Office of Pesticide Programs (OPP...paper copy of the fact sheet, which provides...22161. II. Did EPA Conditionally Approve...that use of the pesticide during the...

2010-09-17

109

76 FR 16415 - Product Cancellation Order for Certain Pesticide Registrations  

Federal Register 2010, 2011, 2012, 2013

...March 23, 2011. FOR FURTHER INFORMATION CONTACT: Veronica Dutch, Pesticide Re- evaluation Division (7508P), Office of Pesticide...308-8585; fax number: (703) 308-8090; e-mail address: dutch.veronica@epa.gov. SUPPLEMENTARY INFORMATION: I....

2011-03-23

110

Assessing the potential for algae and macrophytes to degrade crop protection products in aquatic ecosystems.  

PubMed

Rates of pesticide degradation in aquatic ecosystems often differ between those observed within laboratory studies and field trials. Under field conditions, a number of additional processes may well have a significant role, yet are excluded from standard laboratory studies, for example, metabolism by aquatic plants, phytoplankton, and periphyton. These constituents of natural aquatic ecosystems have been shown to be capable of metabolizing a range of crop protection products. Here we report the rate of degradation of six crop protection products assessed in parallel in three systems, under reproducible, defined laboratory conditions, designed to compare aquatic sediment systems which exclude macrophytes and algae against those in which macrophytes and/or algae are included. All three systems remained as close as possible to the Organisation for Economic Co-operation and Development (OECD) 308 guidelines, assessing degradation of parent compound in the total system in mass balanced studies using ((14) C) labeled compounds. We observed, in all cases where estimated, significant increases in the rate of degradation in both the algae and macrophyte systems when compared to the standard systems. By assessing total system degradation within closed, mass balanced studies, we have shown that rates of degradation are enhanced in water/sediment systems that include macrophytes and algae. The contribution of these communities should therefore be considered if the aquatic fate of pesticides is to be fully understood. PMID:21298708

Thomas, Kevin A; Hand, Laurence H

2011-03-01

111

ORGANOPHOSPHATE PESTICIDE DEGRADATION IN THE PRESENCE OF NATURALLY OCCURRING AQUATIC CONSTITUENTS UNDER DRINKING WATER TREATMENT CONDITIONS  

EPA Science Inventory

Little work to date has solely investigated the kinetics and pathways of pesticide transformations under drinking water treatment conditions. Free chlorine has been found to react with s-triazine, carbamate, and organophosphate pesticides. However, these experimental conditions...

112

MEASURING THE TRANSPORT OF ENDOCRINE DISRUPTING DICARBOXIMIDES AND DEGRADATION PRODUCTS FROM THE SOIL TO THE LOWER TROPOSPHERE  

EPA Science Inventory

A method for measuring the atmospheric flux of a dicarboximide and its degradation products was investigated. A volatile gas laboratory chamber was modified to measure the flux of semi-volatile fungicides. Pesticide application systems and soil incorporation systems were desig...

113

The mobility and degradation of pesticides in soils and the pollution of groundwater resources  

Microsoft Academic Search

Pesticides, the most cost-effective means of pest and weed control, allow the maintenance of current yields and so contribute to economic viability. Concern about the environmental impact of repeated pesticide use has prompted research into the environmental fate of these agents, which can emigrate from treated fields to air, other land and waterbodies. How long the pesticide remains in the

Manuel Arias-Estévez; Eugenio López-Periago; Elena Martínez-Carballo; Jesús Simal-Gándara; Juan-Carlos Mejuto; Luis García-Río

2008-01-01

114

Productivity, pesticides, and management of the Peregrine Falcon in Arizona  

USGS Publications Warehouse

In the decade since research commenced with the Peregrine in Arizona, over 60 sites have been identified which historically or presently are occupied by breeding pairs. Productivity was determined for about 120 breeding attempts from 1975-85. Almost all sites, for which productivity information is available for two or more years, have hatched young. Average values for fledging success were ca. 1.4 young/attempt for all active sites and ca. 2.3 young/attempt for successful sites. Eggshell thickness values were highly varied, but few samples reflect thinning sufficient to cause reproductive failure, and the population appears to be increasing slightly. Management practices which can further benefit the falcon include: controlling pesticide use, habitat protection, and information management.

Ellis, D.H.

1985-01-01

115

40 CFR 152.8 - Products that are not pesticides because they are not for use against pests.  

Code of Federal Regulations, 2010 CFR

...8 Products that are not pesticides because they are not for...substance or article is not a pesticide, because it is not intended...product not containing a pesticide. (b) A product intended to force bees from hives for the...

2009-07-01

116

40 CFR 152.8 - Products that are not pesticides because they are not for use against pests.  

Code of Federal Regulations, 2010 CFR

...8 Products that are not pesticides because they are not for...substance or article is not a pesticide, because it is not intended...product not containing a pesticide. (b) A product intended to force bees from hives for the...

2010-07-01

117

Serum Fibrin Degradation Products Throughout Normal Pregnancy  

Microsoft Academic Search

Fibrin\\/fibrinogen degradation products in the serum of 169 healthy pregnant and 43 healthy non-pregnant subjects of a similar age group showed a significant increase throughout pregnancy, the highest levels being obtained in the third trimester. There was no correlation with plasma fibrinogen levels or euglobulin lysis times. Though these changes may be due to other alterations in pregnancy not primarily

D. G. Woodfield; S. K. Cole; A. G. E. Allan; J. D. Cash

1968-01-01

118

Assessment of model uncertainty during the river export modelling of pesticides and transformation products  

NASA Astrophysics Data System (ADS)

The modelling of organic pollutants in the environment is burdened by a load of uncertainties. Not only parameter values are uncertain but often also the mass and timing of pesticide application. By introducing transformation products (TPs) into modelling, further uncertainty coming from the dependence of these substances on their parent compounds and the introduction of new model parameters are likely. The purpose of this study was the investigation of the behaviour of a parsimonious catchment scale model for the assessment of river concentrations of the insecticide Chlorpyrifos (CP) and two of its TPs, Chlorpyrifos Oxon (CPO) and 3,5,6-trichloro-2-pyridinol (TCP) under the influence of uncertain input parameter values. Especially parameter uncertainty and pesticide application uncertainty were investigated by Global Sensitivity Analysis (GSA) and the Generalized Likelihood Uncertainty Estimation (GLUE) method, based on Monte-Carlo sampling. GSA revealed that half-lives and sorption parameters as well as half-lives and transformation parameters were correlated to each other. This means, that the concepts of modelling sorption and degradation/transformation were correlated. Thus, it may be difficult in modelling studies to optimize parameter values for these modules. Furthermore, we could show that erroneous pesticide application mass and timing were compensated during Monte-Carlo sampling by changing the half-life of CP. However, the introduction of TCP into the calculation of the objective function was able to enhance identifiability of pesticide application mass. The GLUE analysis showed that CP and TCP were modelled successfully, but CPO modelling failed with high uncertainty and insensitive parameters. We assumed a structural error of the model which was especially important for CPO assessment. This shows that there is the possibility that a chemical and some of its TPs can be modelled successfully by a specific model structure, but for other TPs, the model structure may not be suitable. Concluding, this study confirmed that the introduction of TPs into pesticide fate and export modelling from hydrological catchments amplifies parameter uncertainty and model structure uncertainty.

Gassmann, Matthias; Olsson, Oliver; Kümmerer, Klaus

2013-04-01

119

Insulin degradation products from perfused rat kidney  

SciTech Connect

The kidney is a major site for insulin metabolism, but the enzymes involved and the products generated have not been established. To examine the products, we have perfused rat kidneys with insulin specifically iodinated on either the A14 or the B26 tyrosine. Labeled material from both the perfusate and kidney extract was examined by Sephadex G50 and high-performance liquid chromatography (HPLC). In perfusate from a filtering kidney, 22% of the insulin-sized material was not intact insulin on HPLC. With the nonfiltering kidney, 10.6% was not intact insulin. Labeled material from HPLC was sulfitolyzed and reinjected on HPLC. By use of /sup 125/I-iodo(A14)-insulin, almost all the degradation products contained an intact A-chain. By use of /sup 125/I-iodo(B26)-insulin, several different B-chain-cleaved products were obtained. The material extracted from the perfused kidney was different from perfusate products but similar to intracellular products from hepatocytes, suggesting that cellular metabolism by kidney and liver are similar. The major intracellular product had characteristics consistent with a cleavage between the B16 and B17 amino acids. This product and several of the perfusate products are also produced by insulin protease suggesting that this enzyme is involved in the degradation of insulin by kidney.

Duckworth, W.C.; Hamel, F.G.; Liepnieks, J.; Peavy, D.; Frank, B.; Rabkin, R.

1989-02-01

120

Insulin degradation products from perfused rat kidney.  

PubMed

The kidney is a major site for insulin metabolism, but the enzymes involved and the products generated have not been established. To examine the products, we have perfused rat kidneys with insulin specifically iodinated on either the A14 or the B26 tyrosine. Labeled material from both the perfusate and kidney extract was examined by Sephadex G50 and high-performance liquid chromatography (HPLC). In perfusate from a filtering kidney, 22% of the insulin-sized material was not intact insulin on HPLC. With the nonfiltering kidney, 10.6% was not intact insulin. Labeled material from HPLC was sulfitolyzed and reinjected on HPLC. By use of 125I-iodo(A14)-insulin, almost all the degradation products contained an intact A-chain. By use of 125I-iodo(B26)-insulin, several different B-chain-cleaved products were obtained. The material extracted from the perfused kidney was different from perfusate products but similar to intracellular products from hepatocytes, suggesting that cellular metabolism by kidney and liver are similar. The major intracellular product had characteristics consistent with a cleavage between the B16 and B17 amino acids. This product and several of the perfusate products are also produced by insulin protease suggesting that this enzyme is involved in the degradation of insulin by kidney. PMID:2645781

Duckworth, W C; Hamel, F G; Liepnieks, J; Peavy, D; Frank, B; Rabkin, R

1989-02-01

121

A survey for small animal veterinarians regarding flea and tick control pesticide products.  

PubMed

The Canadian Veterinary Medical Association administered a survey to capture the clinical experiences of small animal veterinarians regarding adverse effects observed in cats and dogs following the use of flea and tick control pesticide products. Results of this survey are discussed and compared with pesticide incident reports collected by Health Canada. PMID:22467961

Turner, Vanessa; Chaffey, Cheryl; Ferrao, Patricia

2011-10-01

122

Inoculation with a mixed degrading culture improves the pesticide removal of an on-farm biopurification system.  

PubMed

To investigate whether the pesticide removal in on-farm biopurification systems (BPS) filled with two different types of substrata (biomix and plastic carriers) is affected by inoculation with a pesticide-degrading strain or mixed culture, lab-scale BPS used to treat chloropropham point source contaminations were bioaugmented with either a specialized chloropropham-degrading strain or a chloropropham-degrading enrichment culture. Application of both inoculum types leads to an accelerated degradation activity in the columns filled with plastic carriers. For both substratum types, inoculation with the mixed culture resulted in a lower breakthrough of the toxic intermediate 3-chloroaniline at high hydraulic loads, compared to inoculation with the pure isolate and no inoculation. This study suggests that the use of plastic carrier materials could be a proficient alternative to the use of a conventional biomix as a substratum in on-farm BPS and that inoculation with a mixed degrading culture can reduce the leaching of more mobile toxic intermediates. PMID:23708426

Verhagen, Pieter; De Gelder, Leen; Boon, Nico

2013-10-01

123

Field solar degradation of pesticides and emerging water contaminants mediated by polymer films containing titanium and iron oxide with synergistic heterogeneous photocatalytic activity at neutral pH  

Microsoft Academic Search

Photocatalytic degradation of phenol, nalidixic acid, mixture of pesticides, and another of emerging contaminants in water was mediated by TiO2 and iron oxide immobilized on functionalized polyvinyl fluoride films (PVFf–TiO2–Fe oxide) in a compound parabolic collector (CPC) solar photoreactor. During degradation, little iron leaching (<0.2mgL?1) was observed. Phenol was efficiently degraded and mineralized at operational pH<5 and nalidixic acid degradation

F. Mazille; T. Schoettl; N. Klamerth; S. Malato; C. Pulgarin

2010-01-01

124

Bioaccumulation and degradation of pesticide fluroxypyr are associated with toxic tolerance in green alga Chlamydomonas reinhardtii.  

PubMed

The herbicide fluroxypyr is widely used for controlling weeds and insects but intensive use of fluroxypyr has resulted in its widespread contamination in soils and aquatic ecosystems. To evaluate the eco-toxicity of fluroxypyr to green algae, bioaccumulation and degradation of fluroxypyr in Chlamydomonas reinhardtii, a model unicellular alga, along with its biological adaptation to fluroxypyr toxicity were investigated. The microalgae were treated with fluroxypyr at 0.05-1.00 mg l(-1) for 2 days or 0.50 mg l(-1) for 1-5 days. The growth of C. reinhardtii was stimulated at low levels of fluroxypyr (0.05-0.5 mg l(-1)) but inhibited at high concentrations (0.75-1.00 mg l(-1)). Fluroxypyr was significantly accumulated by C. reinhardtii. Interestingly, the accumulated fluroxypyr could be rapidly degraded in the cells. On day 5 more than 57% of cellular fluroxypyr was degraded. Our results indicated that accumulation and degradation of fluroxypyr occurred simultaneously. Treatment with 0.05-1.00 mg l(-1) fluroxypyr for 30 min induced significant production of reactive oxygen species and as a consequence resulted in accumulation of peroxides and DNA degradation. Additionally, activities of several major antioxidant enzymes were activated in C. reinhardtii exposed to high levels of fluroxypyr. Overall, the present studies represent the initial comprehensive analyses of the green alga C. reinhardtii in adaptation to the fluroxypyr-contaminated aquatic ecosystems. PMID:21153053

Zhang, Shuang; Qiu, Chong Bin; Zhou, You; Jin, Zhen Peng; Yang, Hong

2011-03-01

125

Mechanism and kinetic properties for OH-initiated atmospheric degradation of the organophosphorus pesticide diazinon  

NASA Astrophysics Data System (ADS)

Diazinon is a member of the organophosphorus class of insecticides. It has been regarded as an important atmospheric pollutant because of its high detection-frequency in the air and potential adverse effects on humans and wildlife. In this paper, the reaction mechanism and possible degradation products for the OH-initiated atmospheric degradation of diazinon were investigated and the rate constants of crucial elementary steps over the temperature range of 180-370 K were predicted. Present results show that OH addition to C4 atom in the pyrimidyl ring, H abstraction from the -CH- moiety as well as OH addition to P atom are the dominant pathways for the reaction of diazinon with OH radicals. The dominant degradation products are diazoxon, SO 2, P3, CH 3CHO, P4, CH 3CO, P14 as well as CH 3CHCH 3. This work provides a comprehensive investigation of the OH-initiated atmospheric degradation of diazinon and should help to clarify its potential risk to non-targets.

Zhou, Qin; Sun, Xiaoyan; Gao, Rui; Hu, Jingtian

2011-06-01

126

Effect of fabric geometry on resistance to pesticide penetration and degradation  

Microsoft Academic Search

Cotton is a standard washable fabric for garments and is preferred for workclothing. Agricultural workers' clothing may become contaminated with pesticides. Among other factors, the rate of pesticide solution penetration and transport from the garment to the underlayers, such as undergarments or skin, depends on fabric geometry. In 100% cotton fabrics, the ease of wettability as measured by the drop

Mastura Raheel; Elizabeth Craig Gitz

1985-01-01

127

Guidance for the Reregistration of Pesticide Products Containing Propham as the Active Ingredient.  

National Technical Information Service (NTIS)

The document contains information regarding the registration of pesticide products containing the subject active ingredient. The document includes how to register under a registration standard, regulatory position and rationale, and summaries of data requ...

1987-01-01

128

Guidance for the Reregistration of Pesticide Products Containing Dichlobenil as the Active Ingredient.  

National Technical Information Service (NTIS)

The document contains information regarding the registration of pesticide products containing the subject active ingredient. The document includes how to register under a registration standard, regulatory position and rationale, and summaries of data requ...

1987-01-01

129

Guidance for the Reregistration of Pesticide Products Containing Dipropetryn as the Active Ingredient.  

National Technical Information Service (NTIS)

The document contains information regarding the reregistration of pesticide products containing the subject active ingredient. The document includes how to register under a registration standard, regulatory position and rationale, and summaries of data re...

1985-01-01

130

Guidance for the Reregistration of Pesticide Products Containing Hexazinone as the Active Ingredient,  

National Technical Information Service (NTIS)

The document contains information regarding the registration of pesticide products containing the subject active ingredient. The document includes how to register under a registration standard, regulatory position and rationale, and summaries of data requ...

1988-01-01

131

Guidance for the Reregistration of Pesticide Products Containing Dicofol as the Active Ingredient.  

National Technical Information Service (NTIS)

This document contains information regarding reregistration of pesticide products containing the subject active ingredient. The document includes how to register under a registration standard, regulatory position and rationale, and summaries of data requi...

1983-01-01

132

Guidance for the Reregistration of Pesticide Products Containing Dodine as the Active Ingredient.  

National Technical Information Service (NTIS)

The document contains information regarding the registration of pesticide products containing the subject active ingredient. The document includes how to register under a registration standard, regulatory position and rationale, and summaries of data requ...

1987-01-01

133

Pesticide Free Production of Field Crops: Results of an On-Farm Pilot Project  

Microsoft Academic Search

farmers, researchers (University of Manitoba; Agricul- ture and Agri-Food Canada in Brandon, MB), and ex- Existing strategies for pesticide use reduction in the northern Great tension workers (Manitoba Agriculture and Food Plains have suffered from limited adoption. A novel approach, Pesti- cide Free Production (PFP), was recently developed in Manitoba, (MAF)) developed Pesticide Free Production (PFP)1 Canada. A participatory, on-farm

Orla M. Nazarko; Rene C. Van Acker; Martin H. Entz; Allison Schoofs; Gary Martens

134

76 FR 16417 - Product Cancellation Order for Certain Pesticide Registrations  

Federal Register 2010, 2011, 2012, 2013

...interested in the sale, distribution, or use of pesticides...Agri Packaging & Logistics, Inc., 2509 South Frontage...is March 23, 2011. Any distribution, sale, or use of existing...provided that such sale, distribution, or use is consistent...

2011-03-23

135

DETERMINATION OF HEAVY METALS AND PESTICIDES IN GINSENG PRODUCTS  

EPA Science Inventory

Medicinal plants may carry residuals of environmentally persistent pesticides or assimilate heavy metals in varying degrees. Several factors may influence contaminant accumulation, including species, level and duration of contaminant exposure, and topography. As part of a progra...

136

NON-OCCUPATIONAL EXPOSURES TO PESTICIDES FOR RESIDENTS OF TWO U.S. CITIES  

EPA Science Inventory

The Non-Occupational Pesticide Exposure Study, funded by the U. S. Environmental Protection Agency, was designed to assess total human exposures to 32 pesticides and pesticide degradation products in the non-occupational environment; however, the study focused primarily on inhala...

137

Contamination by Persistent Chemical Pesticides in Livestock Production Systems  

Microsoft Academic Search

The impact of persistent organic pesticides represents one of the major environmental problems as reported in several studies\\u000a and reflected in some mandatory actions at the inter-governmental level. In particular, isomers of Hexachlorocyclohexane (HCH),\\u000a like many others Organochlorine Pesticides (OCPs), are of human health and environmental concern due to their persistence\\u000a in the biosphere. In industrialised countries, Lindane (the ?-isomer

Bruno Ronchi; Pier Paolo Danieli

138

SORPTION, DEGRADATION, AND MINERALIZATION OF CARBARYL IN SOILS, FOR SINGLE-PESTICIDE AND MULTIPLE-PESTICIDE SYSTEMS  

EPA Science Inventory

Sorption, degradation, and mineralization of carbaryl (1-naphthyl N-methylcarbamate) alone and in mixtures with atrazine (2-chloro-4-ethylamino-6-isopropylamino-1,3,5-triazine) and diuron (N1-(3,4-dichlorophenyl)-N, N-dimethylurea) were characterized for two topsoils and their re...

139

Enzymatic degradation of dibutyl phthalate and toxicity of its degradation products  

Microsoft Academic Search

Dibutyl phthalate (DBP) was more efficiently degraded by cutinase compared to yeast esterase; i.e. almost 80% of initial DBP (500 mg l-1) was decomposed within 7.5 h, and nearly 50% of the degraded DBP disappeared within the initial 30 min. The toxicity of the final DBP degradation products were investigated using various recombinant bioluminescent bacteria. Butyl methyl phthalate, the major product of degradation

Yang-Hoon Kim; Jeewon Lee

2005-01-01

140

Cloning of the organophosphorus pesticide hydrolase gene clusters of seven degradative bacteria isolated from a methyl parathion contaminated site and evidence of their horizontal gene transfer  

Microsoft Academic Search

Seven organophosphorus pesticide-degrading bacteria harboring the methyl parathion degrading (mpd) gene were isolated from a methyl parathion contaminated site. In this study, the 4.7 kb mpd gene cluster, conserved in all seven bacteria capable of degrading methyl parathion, was cloned and further analysis revealed that this cluster contained five ORFs and the mpd gene was associated with a mobile element, IS6100.

Ruifu Zhang; Zhongli Cui; Xiaozhou Zhang; Jiandong Jiang; Ji-Dong Gu; Shunpeng Li

2006-01-01

141

Production of apple-based baby food: changes in pesticide residues.  

PubMed

Apples represent the main component of most fruit-based baby food products. Since not only fruit from organic farming, but also conventionally grown fruit is used for baby food production, the occurrence of pesticide residues in the final product is of high concern. To learn more about the fate of these hazardous compounds during processing of contaminated raw material, apples containing altogether 21 pesticide residues were used for preparation of a baby food purée both in the household and at industrial scale (in the baby food production facility). Within both studies, pesticide residues were determined in raw apples as well as in final products. Intermediate product and by-product were also analysed during the industrial process. Determination of residues was performed by a sensitive multi-detection analytical method based on liquid or gas chromatography coupled with mass spectrometry. The household procedure involved mainly the cooking of unpeeled apples, and the decrease of residues was not extensive enough for most of the studied pesticides; only residues of captan, dithianon and thiram dropped significantly (processing factors less than 0.04). On the other hand, changes in pesticide levels were substantial for all tested pesticides during apple processing in the industrial baby food production facility. The most important operation affecting the reduction of residues was removal of the by-products after pulping (rest of the peel, stem, pips etc.), while subsequent sterilisation has an insignificant effect. Also in this case, captan, dithianon and thiram were identified as pesticides with the most evident decrease of residues. PMID:24720736

Kovacova, Jana; Kocourek, Vladimir; Kohoutkova, Jana; Lansky, Miroslav; Hajslova, Jana

2014-06-01

142

Degradation of 2,4-dichlorophenoxyacetic acid by a halotolerant strain of Penicillium chrysogenum: antibiotic production.  

PubMed

The extensive use of pesticides in agriculture has prompted intensive research on chemical and biological methods in order to protect contamination of water and soil resources. In this paper the degradation of the pesticide 2,4-dichlorophenoxyacetic acid by a Penicillium chrysogenum strain previously isolated from a salt mine was studied in batch cultures. Co-degradation of 2,4-dichlorophenoxyacetic acid with additives such as sugar and intermediates of pesticide metabolism was also investigated. Penicillium chrysogenum in solid medium was able to grow at concentrations up to 1000 mg/L of 2,4-dichlorophenoxyacetic acid (2,4-D) with sucrose. Meanwhile, supplementation of the solid medium with glucose and lactose led to fungal growth at concentrations up to 500 mg/L of herbicide. Batch cultures of 2,4-D at 100 mg/L were developed under aerobic conditions with the addition of glucose, lactose and sucrose, showing sucrose as the best additional carbon source. The 2,4-D removal was quantified by liquid chromatography. The fungus was able to use 2,4-D as the sole carbon and energy source under 0%, 2% and 5.9% NaCl. The greatest 2,4-D degradation efficiency was found using alpha-ketoglutarate and ascorbic acid as co-substrates under 2% NaCl at pH 7. Penicillin production was evaluated in submerged cultures by bioassay, and higher amounts of beta-lactam antibiotic were produced when the herbicide was alone. Taking into account the ability of P. chrysogenum CLONA2 to degrade aromatic compounds, this strain could be an interesting tool for 2,4-D herbicide remediation in saline environments. PMID:22629643

Ferreira-Guedes, Sumaya; Mendes, Benilde; Leitão, Ana Lúcia

2012-01-01

143

Pesticide Product Use and Risk of Non-Hodgkin Lymphoma in Women  

PubMed Central

A population-based, incidence case–control study was conducted among women in upstate New York to determine whether pesticide exposure is associated with an increase in risk of non-Hodgkin lymphoma (NHL) among women. The study involved 376 cases of NHL identified through the State Cancer Registry and 463 controls selected from the Medicare beneficiary files and state driver’s license records. Information about history of farm work, history of other jobs associated with pesticide exposure, use of common household pesticide products, and potential confounding variables was obtained by telephone interview. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using an unconditional logistic regression model. The risk of NHL was doubled (OR = 2.12; 95% CI, 1.21–3.71) among women who worked for at least 10 years at a farm where pesticides were reportedly used. When both farming and other types of jobs associated with pesticide exposure were combined, there was a progressive increase in risk of NHL with increasing duration of such work (p = 0.005). Overall cumulative frequency of use of household pesticide products was positively associated with risk of NHL (p = 0.004), which was most pronounced when they were applied by subjects themselves. When exposure was analyzed by type of products used, a significant association was observed for mothballs. The associations with both occupational and household pesticides were particularly elevated if exposure started in 1950–1969 and for high-grade NHL. Although the results of this case–control study suggest that exposure to pesticide products may be associated with an increased risk of NHL among women, methodologic limitations related to selection and recall bias suggest caution in inferring causation.

Kato, Ikuko; Watanabe-Meserve, Hiroko; Koenig, Karen L.; Baptiste, Mark S.; Lillquist, Patricia P.; Frizzera, Glauco; Burke, Jerome S.; Moseson, Miriam; Shore, Roy E.

2004-01-01

144

A dual-template imprinted capsule with remarkably enhanced catalytic activity for pesticide degradation and elimination simultaneously.  

PubMed

A new strategy of reactant-product-dual-template imprinting incorporated with hollow morphology to improve the catalysis efficiency of microspheres was developed. The synthesized capsule can achieve degradation of the reactant and elimination of its product simultaneously. PMID:23264959

Guo, Yong; Guo, Tianying

2013-02-01

145

Target product profile choices for intra-domiciliary malaria vector control pesticide products: repel or kill?  

PubMed Central

Background The most common pesticide products for controlling malaria-transmitting mosquitoes combine two distinct modes of action: 1) conventional insecticidal activity which kills mosquitoes exposed to the pesticide and 2) deterrence of mosquitoes away from protected humans. While deterrence enhances personal or household protection of long-lasting insecticidal nets and indoor residual sprays, it may also attenuate or even reverse communal protection if it diverts mosquitoes to non-users rather than killing them outright. Methods A process-explicit model of malaria transmission is described which captures the sequential interaction between deterrent and toxic actions of vector control pesticides and accounts for the distinctive impacts of toxic activities which kill mosquitoes before or after they have fed upon the occupant of a covered house or sleeping space. Results Increasing deterrency increases personal protection but consistently reduces communal protection because deterrent sub-lethal exposure inevitably reduces the proportion subsequently exposed to higher lethal doses. If the high coverage targets of the World Health Organization are achieved, purely toxic products with no deterrence are predicted to generally provide superior protection to non-users and even users, especially where vectors feed exclusively on humans and a substantial amount of transmission occurs outdoors. Remarkably, this is even the case if that product confers no personal protection and only kills mosquitoes after they have fed. Conclusions Products with purely mosquito-toxic profiles may, therefore, be preferable for programmes with universal coverage targets, rather than those with equivalent toxicity but which also have higher deterrence. However, if purely mosquito-toxic products confer little personal protection because they do not deter mosquitoes and only kill them after they have fed, then they will require aggressive "catch up" campaigns, with behaviour change communication strategies that emphasize the communal nature of protection, to achieve high coverage rapidly.

2011-01-01

146

[Induce of laccase from Trametes gallica and its degradation on neutral dyes and organophosphorus pesticides].  

PubMed

The characteristics of the induction of laccase in Trametes gallica under different initial cultural pH, incubation time by different inducers were discussed, as well as the effects of temperature, pH and time on laccase degradation of six dyes and four organophosphors. The results showed that RB-bright blue, ABTS and o-toluidine affected the production of laccase at different levels, and ABTS was the best inductive agent in our test conditions, whose optimal initial pH and incubation time were 4.0 and 13 days, respectively. The appropriate reaction temperature of the laccase produced was 38 degrees C, and it got a good stability, for it could retain 78.6% of the enzyme activity after 20 min holding at 40 degrees C. Mediated by ABTS, the optimal temperature for laccase to degrade the six types of neutral dyes could be divided into two cases, that was 30 degrees C (neutral black, neutral bordeaux, neutral pink, methyl orange) and 60 degrees C (neutral dark yellow, cresol red), the optimal pH were 6.0 (neutral black), 2.0 (neutral bordeaux, neutral pink) and 4.0 (methyl orange, neutral dark yellow, cresol red), respectively, while the optimal times separately were 6 h (methyl orange, neutral dark yellow, cresol red), 12 h (neutral pink) and 24 h (neutral bordeaux). And using the same inductive agent, the best temperature for laccase to degrade dimethoate, chlorpyrifos, trichlorfon and parathion-pyridazine was 25 degrees C, the suitable time was 9 h, and the optimal pH was 10.0 for dimethoate, chlorpyrifos and parathion-pyridazine, and 8.0 for trichlorfon. PMID:22384601

Jing, De-Jun; Huang, Jian-Bo; Yang, Zhou-Ping; Hu, Rong; Cheng, Zi-Zhang; Huang, Qian-Ming

2011-12-01

147

EXPOSURE OF PRESCHOOL CHILDREN TO CHLORPYRIFOS AND ITS DEGRADATION PRODUCT 3,5,6-TRICHLORO-2-PYRIDINOL IN THEIR EVERYDAY ENVIRONMENTS  

EPA Science Inventory

As part of the Children's Total Exposure to Persistent Pesticides and Other Persistent Organic Pollutants (CTEPP) study, we investigated the exposures of preschool children to chlorpyrifos and its degradation product 3,5,6-trichloro-2-pyridinol (TCP) in their everyday environment...

148

SAFE PESTICIDES/SAFE PRODUCTS MULTI-YEAR PLAN  

EPA Science Inventory

Additional research on pesticides and toxics provides results that support the Federal Insecticide, Fungicide and Rodenticide Act (FIFRA) and Toxic Substances Control Act (TSCA). EPA's multi-year research plan establishes four long-term goals, designed to enhance the Agency's Off...

149

Degradation of pesticide waste taken from a highly contaminated soil evaporation pit in California  

Microsoft Academic Search

The primary methods for disposing of liquid pesticide wastes in California has been the dumping of the liquid materials into soil evaporation pits, ditches, and ponds. Many, if not most of these systems are unlined and have been in use for many years. One such soil pit located in northern California was found to be highly contaminated with an estimated

Wray Winterlin; James N. Seiber; Arthur Craigmill; Terry Baier; James Woodrow; Glen Walker

1989-01-01

150

DESIGNING PESTICIDE METABOLIC PATHWAY/DEGRADATE DATABASES FOR REGISTRANT SUBMITTED HEALTH EFFECTS/ECOLOGICAL EFFECTS DATA  

EPA Science Inventory

OPPTS requires information on the toxic effects of pesticide metabolites as well as the parent chemical. Currently, OPP receives metabolic maps with registrant study data submissions, but there is no efficient way to access previously submitted maps on similar chemicals to help w...

151

Degradation capacity of a 1,2,4-trichlorobenzene mineralizing microbial community for traces of organochlorine pesticides.  

PubMed

A soil-borne microbial community isolated from a contaminated site was previously shown to mineralize 1,2,4-trichlorobenzene (1,2,4-TCB) under aerobic conditions. The key degrader in this community was identified as Bordetella sp. F2. The objective of the study was to test the capacity of the microbial community to degrade a complex mixture of 27 organochlorine compounds and pesticides (OCPs) commonly detected in the environment. The hypothesis was that the microbes would utilize the OCPs as carbon sources at the low concentrations of these compounds, found in natural waters and soil solution. The study was carried out in liquid culture and the changes in concentration of the OCPs were monitored using GC-MS. Data analysis was done using a multivariate analysis method similar to Principal Response Curve (PRC) analysis. Contrary to expectations, the data analysis showed a general trend where higher concentrations were observed in the microbially treated samples relative to the controls. The observed trend was attributed to decreased volatilization due to sorption of the chemicals by microbes since most of the compounds in the cocktail had high Kow values. Nevertheless, when using adequate statistical methods for analysing the very complex data set, correlation of Kow and K(H) values with the loadings of the PRCs showed that three chlorinated mono-aromatics - pentachlorobenzene, pentachloroanisole and octachloroanisole - were amenable to degradation. This provided indications that the community could hold promise for the degradation of higher-chlorinated mono-aromatic OCPs. PMID:20435336

Kengara, Fredrick Orori; Schramm, Karl-Werner; Doerfler, Ulrike; Munch, Jean Charles; Henkelmann, Bernhard; Welzl, Gerhard; Bernhoeft, Silke; Hense, Burkhard; Schroll, Reiner

2010-07-15

152

Glucose degradation products and the peritoneal mesothelium.  

PubMed

Conventional heat-sterilized, glucose-based peritoneal dialysis (PD) fluids contain significant amounts of glucose degradation products (GDPs) such as aldehydes and dicarbonyl compounds (glyoxal, methylglyoxal). These GDPs have been shown to impair cell functions in various in vitro experimental models. In peritoneal mesothelial cells, GDPs dose-dependently inhibit cell proliferation and mediator synthesis. In addition, some GDPs potently promote generation of advanced glycation end-products (AGEs). Immunohistochemistry finds AGEs in the peritoneal membrane of chronic continuous ambulatory peritoneal dialysis (CAPD) patients, suggesting that peritoneal AGE accumulation may be involved in chronic peritoneal fibrosis. The formation of GDPs might be prevented by filter-sterilization of PD fluids. Another option is to separate the glucose and the buffer system in dual-chambered or multi-chambered containers. In these systems, the glucose is kept in a separate compartment at high concentration and very low pH-both conditions being known to minimize the degree of glucose decomposition during autoclaving. Initial experimental evidence suggests that these novel, multi-chambered fluids significantly improve in vitro biocompatibility; however, the clinical relevance of these results remains to be established in clinical trials. PMID:11229607

Jörres, A; Bender, T O; Witowski, J

2000-01-01

153

Identification of degradation products of thiram in water, soil and plants using LC-MS technique.  

PubMed

In order to evaluate the deleterious effects of exposure to pesticides on a target population, a comprehensive study on their degradation in the various segments of ecosystem under varying environmental conditions is needed. In view of this, a study has been carried out on the metabolic pathways of thiram, a dithiocarbamate fungicide, in a variety of matrices namely water and soil under controlled conditions and plants in field conditions. The identification of degradation products was carried out in samples collected at various time points using LC-MS. The degradation products identified can be rationalized as originating by a variety of processes like hydrolysis, oxidation, N-dealkylation and cyclization. As a result of these processes the presence of some metabolites like dimethyl dithiocarbamate, bis(dimethyl carbamoyl) disulphide, bis(dimethyl dithiocarbamoyl) trisulphide and N-methyl-amino-dithiocarbamoyl sulphide was observed in all the cases. However, some different metabolites were observed with the change in the matrix or its characteristics such as cyclised products 2(N, N-dimethyl amino)thiazoline carboxylic acid and 2-thioxo-4-thiazolidine were observed only in plants. The investigations reflect that degradation initiates with hydrolysis, subsequently oxidation/dealkylation, followed by different types of reactions. The pathways seem to be complex and dependent on the matrices. Dimethyl dithiocarbamate and oxon metabolites, which are more toxic than parent compound, seem to persist for a longer time. Results indicate persistence vis-a-vis toxicity of pesticide and its metabolites and also provide a data bank of metabolites for forensic and epidemiological investigations. PMID:22575009

Gupta, Bina; Rani, Manviri; Kumar, Rahul; Dureja, Prem

2012-09-01

154

Toxicity and efficacy of selected pesticides and new acaricides to stored product mites (Acari: Acaridida).  

PubMed

Stored product mites can often infest stored products, but currently there is little information regarding the efficacy of pesticides that can be used for control. In this study we evaluated several common pesticides formulated from single active ingredients (a.i.) or commercially available mixtures (chlorpyrifos, deltamethrin, beta-cyfluthrin, and a combination of deltamethrin and S-bioallethrin), plus an acaricide composed of permethrin, pyriproxyfen and benzyl benzolate, for efficacy against Acarus siro, Tyrophagus putrescentiae, and Aleuroglyphus ovatus. The pesticides were incorporated into the mite diets in a dose range of 10-1000 microg a.i. g(-1) diet. Concentrations for suppression of 50 and 90% population growth and eradication (rC0) of mites were fit to linear regression models. None of the tested pesticides gave complete eradication of A. siro, which was the most tolerant of the three mite species tested. The most effective pesticide Allergoff 175 CS was a combination product (a nano-capsule suspension of permethrin, pyriproxyfen and benzyl benzolate) labeled for dust mites, with rC0 range of 463-2453 microg a.i. (permethrin) g(-1) diet depending on the species. Least effective were chlorpyrifos and deltamethrin. PMID:17674127

Hubert, Jan; Stejskal, Vaclav; Munzbergova, Zuzana; Hajslova, Jana; Arthur, Frank H

2007-01-01

155

Vitamin C Degradation Products and Pathways in the Human Lens*  

PubMed Central

Vitamin C and its degradation products participate in chemical modifications of proteins in vivo through non-enzymatic glycation (Maillard reaction) and formation of different products called advanced glycation end products. Vitamin C levels are particularly high in selected tissues, such as lens, brain and adrenal gland, and its degradation products can inflict substantial protein damage via formation of advanced glycation end products. However, the pathways of in vivo vitamin C degradation are poorly understood. Here we have determined the levels of vitamin C oxidation and degradation products dehydroascorbic acid, 2,3-diketogulonic acid, 3-deoxythreosone, xylosone, and threosone in the human lens using o-phenylenediamine to trap both free and protein-bound adducts. In the protein-free fraction and water-soluble proteins (WSP), all five listed degradation products were identified. Dehydroascorbic acid, 2,3-diketogulonic acid, and 3-deoxythreosone were the major products in the protein-free fraction, whereas in the WSP, 3-deoxythreosone was the most abundant measured dicarbonyl. In addition, 3-deoxythreosone in WSP showed positive linear correlation with age (p < 0.05). In water-insoluble proteins, only 3-deoxythreosone and threosone were detected, whereby the level of 3-deoxythreosone was ?20 times higher than the level of threosone. The identification of 3-deoxythreosone as the major degradation product bound to human lens proteins provides in vivo evidence for the non-oxidative pathway of dehydroascorbate degradation into erythrulose as a major pathway for vitamin C degradation in vivo.

Nemet, Ina; Monnier, Vincent M.

2011-01-01

156

Time-dependent integrity during storage of natural surface water samples for the trace analysis of pharmaceutical products, feminizing hormones and pesticides  

PubMed Central

Monitoring and analysis of trace contaminants such as pharmaceuticals and pesticides require the preservation of the samples before they can be quantified using the appropriate analytical methods. Our objective is to determine the sample shelf life to insure proper quantification of ultratrace contaminants. To this end, we tested the stability of a variety of pharmaceutical products including caffeine, natural steroids, and selected pesticides under refrigerated storage conditions. The analysis was performed using multi-residue methods using an on-line solid-phase extraction combined with liquid chromatography tandem mass spectrometry (SPE-LC-MS/MS) in the selected reaction monitoring mode. After 21 days of storage, no significant difference in the recoveries was observed compared to day 0 for pharmaceutical products, while for pesticides, significant losses occurred for DIA and simazine after 10 days (14% and 17% reduction respectively) and a statistically significant decrease in the recovery was noted for cyanazine (78% disappearance). However, the estrogen and progestogen steroids were unstable during storage. The disappearance rates obtained after 21 days of storage vary from 63 to 72% for the feminizing hormones. Overall, pharmaceuticals and pesticides seem to be stable for refrigerated storage for up to about 10 days (except cyanazine) and steroidal hormones can be quite sensitive to degradation and should not be stored for more than a few days.

2010-01-01

157

Time-dependent integrity during storage of natural surface water samples for the trace analysis of pharmaceutical products, feminizing hormones and pesticides.  

PubMed

Monitoring and analysis of trace contaminants such as pharmaceuticals and pesticides require the preservation of the samples before they can be quantified using the appropriate analytical methods. Our objective is to determine the sample shelf life to insure proper quantification of ultratrace contaminants. To this end, we tested the stability of a variety of pharmaceutical products including caffeine, natural steroids, and selected pesticides under refrigerated storage conditions. The analysis was performed using multi-residue methods using an on-line solid-phase extraction combined with liquid chromatography tandem mass spectrometry (SPE-LC-MS/MS) in the selected reaction monitoring mode. After 21 days of storage, no significant difference in the recoveries was observed compared to day 0 for pharmaceutical products, while for pesticides, significant losses occurred for DIA and simazine after 10 days (14% and 17% reduction respectively) and a statistically significant decrease in the recovery was noted for cyanazine (78% disappearance). However, the estrogen and progestogen steroids were unstable during storage. The disappearance rates obtained after 21 days of storage vary from 63 to 72% for the feminizing hormones. Overall, pharmaceuticals and pesticides seem to be stable for refrigerated storage for up to about 10 days (except cyanazine) and steroidal hormones can be quite sensitive to degradation and should not be stored for more than a few days. PMID:20403158

Aboulfadl, Khadija; De Potter, Cyril; Prévost, Michèle; Sauvé, Sébastien

2010-01-01

158

Degradation of organochlorine pesticides by meat starter in liquid media and fermented sausage  

Microsoft Academic Search

The effect of meat starter on the degradation of DDT and lindane was investigated. The insignificant role of Lactobacillus plantarum in degrading p,p?-DDT and lindane presented in tryptone soya broth (TSB) and mineral salt medium (MSM) with or without 120 ppm nitrite was observed.The degradation of DDT and lindane by Micrococcus varians in TSB and MSM with or without nitrite

A. A. K Abou-Arab

2002-01-01

159

Dicofol: Position Document 4. Intent to Cancel Registrations of Pesticide Products Containing Dicofol; Denial of Applications for Registration of Pesticide Products Containing Dicofol; Conclusion of Special Review; Notice of Final Determination.  

National Technical Information Service (NTIS)

The Position Document addresses the risks and benefits of pesticide products containing the subject active ingredient. The Agency has determined that the use of products containing the subject active ingredient may meet or exceed a risk criterion describe...

1986-01-01

160

Pesticide residues in grapes, wine, and their processing products.  

PubMed

In this review the results obtained in the 1990s from research on the behavior of pesticide residues on grapes, from treatment to harvest, and their fate in drying, wine-making, and alcoholic beverage processing are reported. The fungicide residues on grapes (cyproconazole, hexaconazole, kresoxim-methyl, myclobutanil, penconazole, tetraconazole, and triadimenol), the application rates of which were of a few tens of grams per hectare, were very low after treatment and were not detectable at harvest. Pyrimethanil residues were constant up to harvest, whereas fluazinam, cyprodinil, mepanipyrim, azoxystrobin, and fludioxonil showed different disappearance rates (t(1/2) = 4.3, 12, 12.8, 15.2, and 24 days, respectively). The decay rate of the organophosphorus insecticides was very fast with t(1/2) ranging between 0.97 and 3.84 days. The drying process determined a fruit concentration of 4 times. Despite this, the residue levels of benalaxyl, phosalone, metalaxyl, and procymidone on sun-dried grapes equalled those on the fresh grape, whereas they were higher for iprodione (1.6 times) and lower for vinclozolin and dimethoate (one-third and one-fifth, respectively). In the oven-drying process, benalaxyl, metalaxyl, and vinclozolin showed the same residue value in the fresh and dried fruit, whereas iprodione and procymidone resides were lower in raisins than in the fresh fruit. The wine-making process begins with the pressing of grapes. From this moment onward, because the pesticide on the grape surface comes into contact with the must, it is in a biphasic system, made up of a liquid phase (the must) and a solid phase (cake and lees), and will be apportioned between the two phases. The new fungicides have shown no effect on alcoholic or malolactic fermentation. In some cases the presence of pesticides has also stimulated the yeasts, especially Kloeckera apiculata, to produce more alcohol. After fermentation, pesticide residues in wine were always smaller than those on the grapes and in the must, except for those pesticides that did not have a preferential partition between liquid and solid phase (azoxystrobin, dimethoate, and pyrimethanil) and were present in wine at the same concentration as on the grapes. In some cases (mepanipyrim, fluazinam, and chlorpyrifos) no detectable residues were found in the wines at the end of fermentation. From a comparison of residues in wine obtained by vinification with and without skins, it can be seen that their values were generally not different. Among the clarifying substances commonly used in wine (bentonite, charcoal, gelatin, polyvinylpolypyrrolidone, potassium caseinate, and colloidal silicon dioxide), charcoal allowed the complete elimination of most pesticides, especially at low levels, whereas the other clarifying substances were ineffective. Wine and its byproducts (cake and lees) are used in the industry to produce alcohol and alcoholic beverages. Fenthion, quinalphos, and vinclozolin pass into the distillate from the lees only if present at very high concentrations, but with a very low transfer percantage (2, 1, and 0.1%, respectively). No residue passed from the cake into the distillate, whereas fenthion and vinclozolin pass from the wine, but only at low transfer percentages (13 and 5%, respectively). PMID:10775335

Cabras, P; Angioni, A

2000-04-01

161

Toxicity of pesticide and fertilizer mixtures simulating corn production to eggs of snapping turtles ( Chelydra serpentina)  

Microsoft Academic Search

Many reptiles oviposit in soils associated with agricultural landscapes. We evaluated the toxicity of a pesticide and fertilizer regime similar to those used in corn production in Ontario on the survivorship of exposed snapping turtle (Chelydra serpentina) eggs. The herbicides atrazine, dimethenamid, and glyphosate, the pyrethroid insecticide tefluthrin, and the fertilizer ammonia, were applied to clean soil, both as partial

Shane Raymond de Solla; Pamela Anne Martin; Paul Mikoda

2011-01-01

162

Disposal of pesticide waste from agricultural production in the Al-Batinah region of Northern Oman.  

PubMed

During the last two decades Oman has experienced rapid economic development but this has been accompanied by environmental problems. Manufacturing and agricultural output have increased substantially but initially this was not balanced with sufficient environmental management. Although agriculture in Oman is not usually considered a major component of the economy, government policy has been directed towards diversification of national income and as a result there has been an increasing emphasis on revenue from agriculture and an enhancement of production via the use of irrigation, machinery and inputs such as pesticides. In recent years this has been tempered with a range of interventions to encourage more sustainable production. Certain pesticides have been prohibited; there has been a promotion of organic agriculture and an emphasis on education and awareness programs for farmers. The last point is of especial relevance given the nature of the farm labour market in Oman and a reliance on expatriate and often untrained labour. The research, through a detailed stratified survey, explores the state of knowledge at farm-level regarding the safe disposal of pesticide waste and what factors could enhance or indeed operate against the spread and implementation of that knowledge. Members of the recently constituted Farmers Association expressed greater environmental awareness than their non-member counterparts in that they identified a more diverse range of potential risks associated with pesticide use and disposed of pesticide waste more in accordance with government policy, albeit government policy with gaps. Workers on farms belonging to Association members were also more likely to adhere to government policy in terms of waste disposal. The Farmers Association appears to be an effective conduit for the diffusion of knowledge about pesticide legislation and general awareness, apparently usurping the state agricultural extension service. PMID:23811357

Al Zadjali, Said; Morse, Stephen; Chenoweth, Jonathan; Deadman, Mike

2013-10-01

163

Adsorption, Movement, and Biological Degradation of Large Concentrations of Selected Pesticides in Soils.  

National Technical Information Service (NTIS)

Because of the importance of soil in biologically reducing the quantity and retarding the rate of pollutant movement into groundwater, this laboratory study was initiated to evaluate the adsorption, mobility, and degradation of large concentrations of the...

J. M. Davidson P. S. C. Rao L. T. Ou W. B. Wheeler D. F. Rothwell

1980-01-01

164

Nitrate and natural organic matter in aqueous solutions irradiated by simulated sunlight: Influence on the degradation of the pesticides dichlorprop and terbutylazine.  

PubMed

By means of simulated sunlight, the influence of natural organic matter (NOM) on the photochemical degradation of halogenated pesticides in the absence and presence of nitrate as a precursor of the highly reactive OH radicals in aqueous solutions and freshwater was investigated. Solutions of dichlorprop or terbutylazine (a) in phosphate-buffered demineralized water containing nitrate and/or NOM and (b) in natural freshwaters were irradiated by a 1000-W Xe short-arc lamp. The collimated beam was filtered using a combination of optical filters (WG 320 and WG 295) to simulate the solar spectrum under summer midday conditions. In the absence of nitrate and NOM, the pesticides were degraded photolytically by simulated sunlight. The degradation rates depended on the absorption spectrum in the UVB range and the quantum yield of the degradation. The photochemical degradation of the pesticides was faster in the presence of nitrate due to the sunlight-induced formation of OH radicals. In the absence of nitrate, low concentrations of NOM of a brownwater lake accelerated the degradation due to the formation of reactive species by NOM. At higher concentrations of NOM, the inner filter effect of NOM lowered the degradation rates. In the presence of 50 mg l-1 nitrate, NOM decreased the degradation rate significantly. In case the natural water samples were used as a matrix for the experiments (nitrate concentrations between 2 mg l-1 and 15 mg l-1, DOC concentrations below 2.3 mg l-1), NOM acted mainly as a radiation filter and as a scavenger of OH radicals. As a consequence, in most freshwater systems, the accelerating effect of NOM by the formation of reactive species is of minor importance compared to the inner filter effect and to radical scavenging. PMID:19005835

Schindelin, A J; Frimmel, F H

2000-01-01

165

Field solar degradation of pesticides and emerging water contaminants mediated by polymer films containing titanium and iron oxide with synergistic heterogeneous photocatalytic activity at neutral pH.  

PubMed

Photocatalytic degradation of phenol, nalidixic acid, mixture of pesticides, and another of emerging contaminants in water was mediated by TiO(2) and iron oxide immobilized on functionalized polyvinyl fluoride films (PVF(f)-TiO(2)-Fe oxide) in a compound parabolic collector (CPC) solar photoreactor. During degradation, little iron leaching (<0.2mgL(-1)) was observed. Phenol was efficiently degraded and mineralized at operational pH<5 and nalidixic acid degradation was complete even at pH 7, but mineralization stopped at 35%. Pesticide mixture was slowly degraded (50%) after 150min of irradiation. Degradation of the emergent contaminant mixture was successful for eight compounds and less efficient for six other compounds. The significant reactivity differences between tested compounds were assigned to the differences in structure namely that the presence of complexing or chelating groups enhanced the rates. PVF(f)-TiO(2)-Fe oxide photoactivity gradually increased during 20 days of experiments. X-ray photoelectron spectroscopy (XPS) measurements revealed significant changes on the catalyst surface. These analyses confirm that during photocatalysis mediated by PVF(f)-TiO(2)-Fe oxide, some iron leaching led to enlargement of the TiO(2) surface exposed to light, increasing its synergy with iron oxides and leading to enhanced pollutant degradation. PMID:20362319

Mazille, F; Schoettl, T; Klamerth, N; Malato, S; Pulgarin, C

2010-05-01

166

Community air monitoring for pesticides. Part 1: selecting pesticides and a community.  

PubMed

The CA Department of Pesticide Regulation (CDPR) developed methods to select pesticides and a community to fulfill criteria for an ambient air monitoring study it conducted as part of the CA Environmental Protection Agency's Environmental Justice Action Plan. Using a scoring system, CDPR evaluated 100 pesticides based on statewide-reported pesticide use, volatility, and priority in CDPR's risk assessment process (indicators of exposure and toxicity) to produce a list of pesticides to consider as candidates for monitoring. The CDPR also evaluated and scored 83 communities based on demographics and health factors, availability of cumulative impacts data, and reported pesticide use to create a list of community candidates. The scores provide relative rankings to distinguish more highly impacted communities from less impacted ones and to identify which pesticides might contribute most to potential adverse health effects. These methods use criteria that can be quantified, validated, and verified in order to provide a transparent and fair selection process. Based on public comments and highest scores, CDPR recommended 40 pesticides (including some of their degradation products) and one community for its yearlong monitoring study. The CDPR then further refined its list of pesticides by soliciting input from local and technical advisory groups. The CDPR plans to use these methods to select pesticides and communities in future monitoring activities. PMID:24362496

Segawa, Randy; Levine, Johanna; Neal, Rosemary; Brattesani, Madeline

2014-03-01

167

The Microbial Degradation of Aromatic Petroleum Products.  

National Technical Information Service (NTIS)

Pseudomonas Pxy was shown to oxidize para- and meta-xylene to the corresponding toluic acids. The latter compounds were oxidized to 4- and 3-methylcatechols prior to the enzymatic fission of the aromatic nucleus. Pathways are proposed for the degradation ...

D. T. Gibson

1977-01-01

168

The austral peregrine falcon: Color variation, productivity, and pesticides  

USGS Publications Warehouse

The austral peregrine falcon (Falco peregrinus cassini) was studied in the Andean foot- hills and across the Patagonian steppe from November to December 1981. The birds under study (18 pairs) were reproducing at or near normal (pre-DDT) levels for other races. Pesticide residues, while elevated, were well below the values associated with reproductive failure in other populations. With one exception, eggshells were not abnormally thin. The peregrine falcon in Patagonia exhibits extreme color variation. Pallid birds are nearly pure white below (light cream as juveniles), whereas normally pigmented birds are black-crowned and conspicuously barred with black ventrally. Rare individuals of the Normal Phase display black heads, broad black ventral barring, and warm reddish-brown ventral background coloration.

Ellis, D.H.

1985-01-01

169

Organophosphorus (OP) Pesticide Degradation in the Presence of Chlorinated Oxidants: Kinetics, Modeling, and Structure-Activity Relationships  

EPA Science Inventory

The rates and pathways for pesticide transformation during drinking water treatment are known for only a few pesticides and under limited conditions. The resulting oxons are more toxic than the parent pesticides. The transformation rates and pathways for chlorpyrifos, an OP pest...

170

Degradation of caffeic acid in subcritical water and online HPLC-DPPH assay of degradation products.  

PubMed

Caffeic acid was subjected to degradation under subcritical water conditions within 160-240 °C and at a constant pressure of 5 MPa in a continuous tubular reactor. Caffeic acid degraded quickly at these temperatures; the main products identified by liquid chromatography-diode array detection/mass spectrometry were hydroxytyrosol, protocatechuic aldehyde, and 4-vinylcatechol. The reaction rates for the degradation of caffeic acid and the formation of products were evaluated. Online high-performance liquid chromatography/2,2-diphenyl-1-picryhydrazyl assay was used to determine the antioxidant activity of each product in the solution. It was found that the overall antioxidant activity of the treated solution did not change during the degradation process. This study showed a potential of formation of antioxidants from natural phenolic compounds under these subcritical water conditions, and this may lead to a discovering of novel antioxidants compounds during the extraction by this technique. PMID:24483598

Khuwijitjaru, Pramote; Suaylam, Boonyanuch; Adachi, Shuji

2014-02-26

171

Eleven-year trend in acetanilide pesticide degradates in the Iowa River, Iowa.  

PubMed

Trends in concentration and loads of acetochlor, alachlor, and metolachlor and their ethanasulfonic (ESA) and oxanilic (OXA) acid degradates were studied from 1996 through 2006 in the main stem of the Iowa River, Iowa and in the South Fork Iowa River, a small tributary near the headwaters of the Iowa River. Concentration trends were determined using the parametric regression model SEAWAVE-Q, which accounts for seasonal and flow-related variability. Daily estimated concentrations generated from the model were used with daily streamflow to calculate daily and yearly loads. Acetochlor, alachlor, metolachlor, and their ESA and OXA degradates were generally present in >50% of the samples collected from both sites throughout the study. Their concentrations generally decreased from 1996 through 2006, although the rate of decrease was slower after 2001. Concentrations of the ESA and OXA degradates decreased from 3 to about 23% yr. The concentration trend was related to the decreasing use of these compounds during the study period. Decreasing concentrations and constant runoff resulted in an average reduction of 10 to >3000 kg per year of alachlor and metolachlor ESA and OXA degradates being transported out of the Iowa River watershed. Transport of acetochlor and metolachlor parent compounds and their degradates from the Iowa River watershed ranged from <1% to about 6% of the annual application. These trends were related to the decreasing use of these compounds during the study period, but the year-to-year variability cannot explain changes in loads based on herbicide use alone. The trends were also affected by the timing and amount of precipitation. As expected, increased amounts of water moving through the watershed moved a greater percentage of the applied herbicides, especially the relatively soluble degradates, from the soils into the rivers through surface runoff, shallow groundwater inflow, and subsurface drainage. PMID:23099949

Kalkhoff, Stephen J; Vecchia, Aldo V; Capel, Paul D; Meyer, Michael T

2012-01-01

172

Degradation product pattern and morphology changes as means to differentiate abiotically and biotically aged degradable polyethylene  

Microsoft Academic Search

Degradation product patterns and morphology changes are demonstrated to be means by which to differentiate between physical\\/chemical (abiotic) and biological (biotic) ageing of degradable polymers. Comparison is made between low-density polyethylene (LDPE), LDPE + 7.7% starch and LDPE + 20% (starch + pro-oxidant). Pro-oxidized samples were subjected to aqueous sterile and aqueous biotic (Arthrobacter paraffineus) environments at ambient temperatures for

Ann-Christine Albertsson; Camilla Barenstedt; Sigbritt Karlsson; Torbjörn Lindberg

1995-01-01

173

Guidance for the Reregistration of Pesticide Products Containing Bentazon as the Active Ingredient. EPA Case No. 182.  

National Technical Information Service (NTIS)

The document contains information regarding reregistration of pesticide products containing the subject active ingredient. The document includes how to register under a registration standard, regulatory position and rationale, and summaries of data requir...

1985-01-01

174

75 FR 44247 - Product Cancellation Order for Certain Pesticide Registrations  

Federal Register 2010, 2011, 2012, 2013

...the registrations identified in Table 1. Accordingly, the Agency hereby...product registrations identified in Table 1 are canceled. The effective date...stocks of the products identified in Table 1 in a manner inconsistent with any of the...

2010-07-28

175

Leaching of azoxystrobin and its degradation product R234886 from Danish agricultural field sites.  

PubMed

The objective was to estimate leaching of the fungicide azoxystrobin (methyl (?E)-2-[[6-(2-cyanophenoxy)-4-pyrimidinyl]oxy]-?-(methoxymethylene)benzene-acetate) and one of its primary degradation products R234886 ([(E)-2-(2-[6-cyanophenoxy)-pyrimidin-4-yloxyl]-phenyl-3-methoxyacrylic acid], major fraction) at four agricultural research fields (one sandy and three loamy) in Denmark. Water was sampled from tile drains, suction cups and groundwater wells for a minimum period of two years after application of azoxystrobin. Neither azoxystrobin nor R234886 were detected at the sandy site, but did leach through loamy soils. While azoxystrobin was generally only detected during the first couple of months following application, R234886 leached for a longer period of time and at higher concentrations (up to 2.1?gL(-1)). Azoxystrobin is classified as very toxic to aquatic organisms and R234886 as very harmful. Our study shows that azoxystrobin and R234886 can leach through loamy soils for a long period of time following application of the pesticide and thereby pose a potential threat to vulnerable aquatic environments and drinking water resources. We thus recommend the inclusion of azoxystrobin and R234886 in pesticide monitoring programmes and further investigation of their long-term ecotoxicological effects. PMID:22497784

Jørgensen, Lisbeth Flindt; Kjær, Jeanne; Olsen, Preben; Rosenbom, Annette Elisabeth

2012-07-01

176

A multi-residue method for the analysis of pesticides and pesticide degradates in water using HLB solid-phase extraction and gas chromatography-ion trap mass spectrometry  

USGS Publications Warehouse

A method was developed for the analysis of over 60 pesticides and degradates in water by HLB solid-phase extraction and gas-chromatography/mass spectrometry. Method recoveries and detection limits were determined using two surface waters with different dissolved organic carbon (DOC) concentrations. In the lower DOC water, recoveries and detection limits were 80%-108% and 1-12 ng/L, respectively. In the higher DOC water, the detection limits were slightly higher (1-15 ng/L). Additionally, surface water samples from four sites were analyzed and 14 pesticides were detected with concentrations ranging from 4 to 1,200 ng/L. ?? 2008 Springer Science+Business Media, LLC.

Hladik, M. L.; Smalling, K. L.; Kuivila, K. M.

2008-01-01

177

78 FR 24195 - Product Cancellation Order for Certain Pesticide Registrations  

Federal Register 2010, 2011, 2012, 2013

...technical products, listed in Table 1. of Unit II., will be effective...allethrins end use products listed in Table 2. of Unit II. will be effective...of the products identified in Tables 1. and 2. of Unit II. in a manner inconsistent with any of...

2013-04-24

178

Levels of Organochlorine Pesticides in Crops and Related Products From Vojvodina, Serbia: Estimated Dietary Intake  

Microsoft Academic Search

Levels of 16 organochlorine pesticides (OCPs) were investigated in 39 composite samples of agricultural crops, related by-products,\\u000a and foodstuffs collected in Vojvodina, Serbia, in 2002 through 2004. After extraction and cleanup, OCPs were determined by\\u000a capillary gas chromatography using electron-capture detection. The highest mean level of 0.971 ng\\/g whole weight (ww) was\\u000a found for ?-HCH in wheat flour samples. OCPs

B. Škrbi?; Z. Predojevi?

2008-01-01

179

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

PubMed

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

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

2009-12-01

180

On pyrolysis of waste tire: Degradation rate and product yields  

Microsoft Academic Search

A promising and realistic alternative for the reuse of waste tire is the energy and resource technology, pyrolysis, which converts the polymer waste to useful chemical products or fuels. For general engineering purposes, this paper presents studies on the degradation rate and product yields of waste tire during pyrolysis without a catalyst. A thermal gravimetric analyser (TGA) was used to

Yu-Min Chang

1996-01-01

181

A study of the products of PVC thermal degradation  

Microsoft Academic Search

PVC thermal degradation in vacuum up to 500 °C has been followed by recording the relative rate of volatile product formation by thermal volatilisation analysis while monitoring by mass spectrometry the formation of the main products: HCl, aromatic and aliphatic hydrocarbons, and non-condensable gases (CH4, H2). The material balance after pyrolysis has been evaluated. The liquid fraction collected during pyrolysis

Ian C. McNeill; Livia Memetea; William J. Cole

1995-01-01

182

Insulin degradation products from perfused rat kidney  

Microsoft Academic Search

The kidney is a major site for insulin metabolism, but the enzymes involved and the products generated have not been established. To examine the products, we have perfused rat kidneys with insulin specifically iodinated on either the A14 or the B26 tyrosine. Labeled material from both the perfusate and kidney extract was examined by Sephadex G50 and high-performance liquid chromatography

W. C. Duckworth; F. G. Hamel; J. Liepnieks; D. Peavy; B. Frank; R. Rabkin

1989-01-01

183

Ion chromatographic identification and quantification of glycol degradation products  

Microsoft Academic Search

In water-based heat transfer systems, frequently glycols are added to the water to obtain freeze protection. For this purpose, ethylene glycol (EG) is the most common substance used. When heated, the glycol will slowly degrade and the pH of the glycol–water mixture will decrease, leading to corrosion and foaming problems. Carboxylic acids were identified as the main degradation products. Quantification

M. Madera; W. Höflinger; R. Kadnar

2003-01-01

184

Microbial adaption to a pesticide in agricultural soils: Accelerated degradation of 14C-atrazine in field soils from Brazil and Belgium  

NASA Astrophysics Data System (ADS)

An increasing demand for food, feed and bioenergy, and simultaneously a decline of arable land will require an intensive agricultural production including the use of pesticides. With an increasing use of pesticides the occurrence of an accelerated degradation potential has to be assessed. Atrazine [2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine] is one of the most widely used herbicides in the world. Even though its use was banned in several countries it is still widely used throughout America and the Asia-Pacific region. Atrazine is the most widely used herbicide in maize plantations in Brazil and the US. The use of atrazine in Belgium and all EU member states was banned in September 2004, with the permission to consume existing stocks until October 2005. Atrazine and its residues are still regularly detected in soil, ground and surface waters even years after its prohibition. Its persistence in soil and in association with organic particles might become crucial in terms of erosion due to climate and environmental changes. Due to its potential microbiological accessibility, the microbial mineralization of atrazine competes with chemical/physical interaction such as sorption and binding processes of the chemical molecule in the soil matrix. Binding or intrusion of the chemical on soil components results in a decrease of its accessibility for soil microbes, which does not necessarily exclude the molecule from environmental interactions. In the present study the accelerated atrazine degradation in agriculturally used soils was examined. Soil samples were collected from a Rhodic Ferralsol, Campinas do Sul, South Brazil, and Geric Ferralsol, Correntina, Northeastern Brazil. The sampling site of the Rhodic Ferralsol soil has been under crop rotation (soybean/wheat/maize/oat) since 1990. The Geric Ferralsol site has alternately been cultivated with maize and soybean since 2000. Both areas have been treated biennially with atrazine at recommended doses of 1.5 - 3.0 kg ha-1. Additionally, samples were taken from a Belgian field which was used for corn-plantations and which was regularly treated with atrazine for the last 30 years in varying doses of 0.5 - 3.0 kg ha-1. The experiment was performed using 14C-labelled and unlabelled atrazine in accordance to a field application dose of 3 mg kg-1 for the Brazilian soils, and 1 mg kg-1 for the Belgian soil, equaling approximately 3.0 and 1.0 kg ha-1, respectively. All soils with atrazine application history showed a high extent of atrazine mineralization, indicating a highly adapted microbial community being able to mineralize this pesticide. After 15 days of incubation, about 75 % of the initially applied 14C-atrazine was mineralized in the Rhodic Ferralsol, while in the Geric Ferralsol it did not exceed 15 % of the total applied 14C-activity. After a total incubation time of 85 days, the amount mineralized reached 82 % in the Rhodic Ferralsol and 74 % in the Geric Ferralsol. In the Belgian soil, after a total incubation time of 92 days, the mineralized amount of atrazine reached 83% of the initially applied 14C-activity in the atrazine treated soil for the slurry setup. A maximum of atrazine mineralization was observed in the treated field soil between 6 and 7 days of incubation for both, 50% WHCmax and slurry setups. The total 14C-atrazine mineralization was equally high for 50% WHCmax in the atrazine treated soil, totaling 81%. The formation of desorbable metabolites as well as the formation of unextractable, bound atrazine residues during the incubation process was monitored by desorption and accelerated solvent extraction, and successive LC-MSMS and LSC analyses, subsequent to sample oxidation. With increasing incubation time the presence of atrazine metabolites increased in the extracts, with hydroxyl-atrazine as the main metabolite.

Jablonowski, Nicolai David; Martinazzo, Rosane; Hamacher, Georg; Accinelli, Cesare; Köppchen, Stephan; Langen, Ulrike; Linden, Andreas; Krause, Martina; Burauel, Peter

2010-05-01

185

78 FR 25438 - Product Cancellation Order for Certain Pesticide Registrations  

Federal Register 2010, 2011, 2012, 2013

...date of cancellation of the products listed in Table 2 is December 31, 2014. Any distribution, sale...existing stocks of the products identified in Table 1 and Table 2 of Unit II. in a manner inconsistent with any of the provisions for...

2013-05-01

186

78 FR 64938 - Product Cancellation Order for Certain Pesticide Registrations  

Federal Register 2010, 2011, 2012, 2013

...the registrations identified in Table 1a and 1b of Unit II. Accordingly...product registrations identified in Table 1a and 1b of Unit II. are canceled...of the products identified in Table 1a and 1b of Unit II. in a manner inconsistent with any of...

2013-10-30

187

78 FR 59019 - Product Cancellation Order for Certain Pesticide Registrations  

Federal Register 2010, 2011, 2012, 2013

...the registrations identified in Table 1 of Unit II. Accordingly, the...product registrations identified in Table 1 of Unit II. are canceled...of the products identified in Table 1 of Unit II. in a manner inconsistent with any of the...

2013-09-25

188

Exposures of preschool children to chlorpyrifos and its degradation product 3,5,6-trichloro-2-pyridinol in their everyday environments  

Microsoft Academic Search

As part of the Children's Total Exposure to Persistent Pesticides and Other Persistent Organic Pollutants (CTEPP) study, we investigated the exposures of preschool children to chlorpyrifos and its degradation product 3,5,6-trichloro-2-pyridinol (TCP) in their everyday environments. During this study, the participants were still able to purchase and apply chlorpyrifos at their homes or day care centers. Participants were recruited randomly

Marsha K Morgan; Linda S Sheldon; Carry W Croghan; Paul A Jones; Gary L Robertson; Jane C Chuang; Nancy K Wilson; Christopher W Lyu

2005-01-01

189

Hydrogeology and Water Quality of the Pepacton Reservoir Watershed in Southeastern New York. Part 1. Concentrations of pesticides and their degradates in stream baseflow, 2000-2001  

USGS Publications Warehouse

Baseflow samples were collected from 20 small streams in the Pepacton Reservoir watershed in Delaware County, N.Y., from December 2000 through November 2001 as part of an investigation to define the occurrence of pesticides in shallow ground water in watersheds containing either a recent (2001) corn crop, a previous (1993-94) corn crop, or no history of row-crop cultivation. Baseflow water quality was assumed to represent the chemical quality of shallow ground water within the drainage area above each sampling site. Baseflow samples were analyzed for 57 pesticides and pesticide degradates. Three herbicides (atrazine, metolachlor and simazine) and three herbicide degradates (alachlor ESA [ethanesulfonic acid], deethylatrazine, and metolachlor ESA) were detected, but no concentrations exceeded any Federal or State water-quality criteria, and the maximum concentrations of all compounds except metolachlor ESA were less than 0.10 microgram per liter. The most frequently detected compounds (atrazine, metolachlor, deethylatrazine and metolachlor ESA) are either those typically used on corn crops, or those whose parent compounds are commonly used on corn crops and have been detected in streams that drain row-crop settings elsewhere in New York State. The pesticide and pesticide-degradate concentrations in baseflow samples collected in December 2000 and July 2001 samples generally corresponded to the amount of cornfield acreage in each watershed in 2001. The types of pesticides detected, and their median concentrations, were similar to those noted in two previous ground-water studies in row-crop areas elsewhere in upstate New York. Also the SAM ratios (ratio of metolachlor ESA concentration to metolachlor concentration) for the Pepacton samples were similar to those for ground-water samples from other agricultural settings in upstate New York, but were significantly higher than that for stormflow and baseflow samples collected in 1997-98 from Canajoharie Creek, an upstate stream that drains row-crop farmland. These comparisons confirm that the baseflow samples were derived from, and were representative of, ground water in their respective watersheds. Late-summer decreases in atrazine and deethylatrazine concentrations at a site where corn was grown in 2001 may have resulted from the seasonally dry conditions and the accompanying decrease in ground-water discharge from the upper-most part of the surficial aquifer system to streams. The lack of a similar decrease in metolachlor ESA concentrations during this period may reflect the transport of metolachlor ESA to deeper parts of the surficial aquifer that continued to discharge to streams during the dry period.

Phillips, Patrick J.; Heisig, Paul M.

2004-01-01

190

Photosensitized degradation in water of the phenolic pesticides bromoxynil and dichlorophen in the presence of riboflavin, as a model of their natural photodecomposition in the environment.  

PubMed

Within the context of environmentally friendly methods for the elimination of surface-water pollutants, the photodegradation of the phenolic pesticides bromoxynil (BXN) and dichlorophen (DCP) under simulated natural conditions has been studied. The work was done in the presence of the visible-light absorber photosensitizer riboflavin (Rf), usually present in trace quantities in natural waters. Under aerobic conditions, an efficient photooxidation of both pesticides was observed. The relatively intricate photochemical mechanism involves pesticide and oxygen consumption and, to a lesser extent, Rf degradation. The kinetic and mechanistic study supports that both H(2)O(2) and singlet molecular oxygen, O(2)((1)?(g)), are involved in the process. Kinetic data for the O(2)((1)?(g))-mediated oxidation indicate that BXN and DCP are photodegraded with this species faster than the parent compound phenol, very frequently employed as a model for aquatic contaminants, likely due to their lower pK(a) values. This observation allows the design of phenolic pesticides with different photodegradation rates under environmental conditions. PMID:21130569

Escalada, Juan P; Pajares, Adriana; Gianotti, José; Biasutti, Alicia; Criado, Susana; Molina, Patricia; Massad, Walter; Amat-Guerri, Francisco; García, Norman A

2011-02-15

191

76 FR 18995 - Pesticides; Regulation to Clarify Labeling of Pesticides for Export  

Federal Register 2010, 2011, 2012, 2013

...to Clarify Labeling of Pesticides for Export AGENCY: Environmental Protection Agency...of pesticides and devices intended for export. Internal review of the regulations revealed...potentially affected by this action if you export a pesticide product, a pesticide...

2011-04-06

192

DEGRADATION AND MIGRATION OF VINCLOZOLIN IN SAND AND SOIL  

EPA Science Inventory

The migration of the dicarboximide fungicide vinclozolin and its principal degradation products through porous media was experimentally determined by simulating pesticide applications to a 23-30 mesh Ottawa sand and a North Carolina Piedmont, aquic hapludult soil in laboratory ...

193

Isolation and characterization of a degradation product of deflazacort.  

PubMed

Deflazacort (DFZ) is an oxazoline derivative of prednisolone with anti-inflammatory and immunosuppressive activity. The aim of this study was to investigate and to identify the main degradation product of DFZ, and to evaluate the anti-inflammatory effect of both DFZ and its major degradation product (namely DDP1). DFZ was subjected to alkaline and acid degradation. In 0.1 N NaOH, DFZ was immediately degraded and 99.0% of product DDP1 was detected by high performance liquid chromatography (HPLC). The HPLC method was ideal to separate the primary and other minor degradation products and was carried out using C18 column, mobile phase consisting of water: acetonitrile: (60:40, v/v) with flow rate of 1.0 mL/min and detection at 244 nm. DDP1 was isolated and identified as 21-hydroxy deflazacort (21-OH-DFZ) by NMR, IR and LCMS. The in vivo pharmacological assays showed that both DFZ as 21-OH-DFZ are active in in vivo and in vitro inflammatory models, but 21-OH-DFZ is more potent than DFZ. PMID:22822536

Paulino, A S; Rauber, G; Deobald, A M; Paulino, N; Sawaya, A C H F; Eberlin, M N; Cardoso, S G

2012-06-01

194

Solvent degradation products in nuclear fuel processing solvents  

SciTech Connect

The Savannah River Plant uses a modified Purex process to recover enriched uranium and separate fission products. This process uses 7.5% tri-n-butyl phosphate (TBP) dissolved in normal paraffin hydrocarbons for the solvent extraction of a nitric acid solution containing the materials to be separated. Periodic problems in product decontamination result from solvent degradation. A study to improve process efficiency has identified certain solvent degradation products and suggested mitigation measures. Undecanoic acid, lauric acid, and tridecanoic acid were tentatively identified as diluent degradation products in recycle solvent. These long-chain organic acids affect phase separation and lead to low decontamination factors. Solid phase extraction (SPE) was used to concentrate the organic acids in solvent prior to analysis by high performance liquid chromatography (HPLC). SPE and HPLC methods were optimized in this work for analysis of decanoic acid, undecanoic acid, and lauric acid in solvent. Accelerated solvent degradation studies with 7.5% TBP in normal paraffin hydrocarbons showed that long-chain organic acids and long-chain alkyl butyl phosphoric acids are formed by reactions with nitric acid. Degradation of both tributyl phosphate and hydrocarbon can be minimized with purified normal paraffin replacing the standard grade presently used. 12 refs., 1 fig., 3 tabs.

Shook, H.E. Jr.

1988-06-01

195

Pesticide use in banana and plantain production and risk perception among local actors in Talamanca, Costa Rica  

Microsoft Academic Search

The Talamanca County in Costa Rica has large-scale banana and small-scale plantain production, probably causing pesticide exposure in indigenous children. We explored to what extent different community actors are aware of children's pesticide hazards and how their awareness related to socio-economical and cultural conditions. Methods comprised eight focus groups with fathers and mothers separately, 27 semi-structured interviews to key actors,

Douglas Barraza; Kees Jansen; Berna van Wendel de Joode; Catharina Wesseling

2011-01-01

196

Development of automated online gel permeation chromatography–gas chromatograph mass spectrometry for measuring multiresidual pesticides in agricultural products  

Microsoft Academic Search

An automated online gel permeation chromatography–gas chromatograph mass spectrometer (GPC–GC\\/MS) was developed for the rapid determination of residual pesticides in agricultural products. Pesticides were extracted from homogenized food samples with acetonitrile and decontaminated via the matrix solid-phase dispersion (MSPD) technique, using a primary secondary amine as sorbent prior to GPC–GC\\/MS analysis. A slightly modified preparation method and automated GPC step

Li-Bin Liu; Yuki Hashi; Ya-Ping Qin; Hai-Xia Zhou; Jin-Ming Lin

2007-01-01

197

Pesticide use in banana and plantain production and risk perception among local actors in Talamanca, Costa Rica  

SciTech Connect

The Talamanca County in Costa Rica has large-scale banana and small-scale plantain production, probably causing pesticide exposure in indigenous children. We explored to what extent different community actors are aware of children's pesticide hazards and how their awareness related to socio-economical and cultural conditions. Methods comprised eight focus groups with fathers and mothers separately, 27 semi-structured interviews to key actors, and field observations. As a whole, the indigenous plantain farmers and banana plantation workers had some general knowledge of pesticides concerning crop protection, but little on acute health effects, and hardly any on exposure routes and pathways, and chronic effects. People expressed vague ideas about pesticide risks. Inter-community differences were related to pesticide technologies used in banana and plantain production, employment status on a multinational plantation versus smallholder status, and gender. Compared to formalized practices on transnational company plantations, where workers reported to feel protected, pesticide handling by plantain smallholders was not perceived as hazardous and therefore no safety precautions were applied. Large-scale monoculture was perceived as one of the most important problems leading to pesticide risks in Talamanca on banana plantations, and also on neighboring small plantain farms extending into large areas. Plantain farmers have adopted use of highly toxic pesticides following banana production, but in conditions of extreme poverty. Aerial spraying in banana plantations was considered by most social actors a major determinant of exposure for the population living nearby these plantations, including vulnerable children. We observed violations of legally established aerial spraying distances. Economic considerations were most mentioned as the underlying reason for the pesticide use: economic needs to obtain the production quantity and quality, and pressure to use pesticides by other economic agents such as middlemen. Risk perceptions were modulated by factors such as people's tasks and positions in the production process, gender, and people's possibilities to define their own social conditions (more fatalistic perceptions among banana workers). The challenge for the future is to combine these insights into improved health risk assessment and management that is culturally adequate for each particular community and agricultural context. - Research highlights: {yields} A first study on pesticide risk perception in Costa Rica. {yields} One of the few studies performed in the indigenous populations in Talamanca. {yields} Economic considerations prevailed above health risks in both communities. {yields} Our findings provide valuable information for multiple social actors.

Barraza, Douglas, E-mail: dbarraza@una.ac.cr [Central American Institute for Studies on Toxic Substances, Universidad Nacional, Heredia (Costa Rica) [Central American Institute for Studies on Toxic Substances, Universidad Nacional, Heredia (Costa Rica); Technology and Agrarian Development Group, Wageningen University (Netherlands); Jansen, Kees [Technology and Agrarian Development Group, Wageningen University (Netherlands)] [Technology and Agrarian Development Group, Wageningen University (Netherlands); Wendel de Joode, Berna van; Wesseling, Catharina [Central American Institute for Studies on Toxic Substances, Universidad Nacional, Heredia (Costa Rica)] [Central American Institute for Studies on Toxic Substances, Universidad Nacional, Heredia (Costa Rica)

2011-07-15

198

75 FR 82387 - Product Cancellation Order for Certain Pesticide Registrations  

Federal Register 2010, 2011, 2012, 2013

...the fenoxycarb registrations (Table 1A), the Agency hereby orders...propetamphos registrations (Table 1B), the Agency hereby orders...of the products identified in Table 1A and 1B of Unit II. in a manner inconsistent with any of...

2010-12-30

199

77 FR 26004 - Product Cancellation Order for Certain Pesticide Registrations  

Federal Register 2010, 2011, 2012, 2013

...registrations identified in Tables 1 through 4 of Unit II. Accordingly...registrations identified in Tables 1 through 4 of Unit II. are...of the products identified in Tables 1 through 4 of Unit II. in a manner inconsistent with any of...

2012-05-02

200

Solar photocatalytic activity of TiO2 modified with WO3 on the degradation of an organophosphorus pesticide.  

PubMed

In this study, the solar photocatalytic activity (SPA) of WO3/TiO2 photocatalysts synthesized by the sol-gel method with two different percentages of WO3 (2 and 5%wt) was evaluated using malathion as a model contaminant. For comparative purpose bare TiO2 was also prepared by sol-gel process. The powders were characterized by X-ray diffraction (XRD), Raman spectroscopy, diffuse reflectance UV-vis spectroscopy (DRUV-vis), specific surface area by the BET method (SSABET), scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM) and scanning transmission electron microscopy with a high annular angle dark field detector (STEM-HAADF). The XRD, Raman, HRTEM and STEM-HAADF analyses indicated that WO3 was present as a monoclinic crystalline phase with nanometric cluster sizes (1.1 ± 0.1 nm for 2% WO3/TiO2 and 1.35 ± 0.3 nm for 5% WO3/TiO2) and uniformly dispersed on the surface of TiO2. The particle size of the materials was 19.4 ± 3.3 nm and 25.6 ± 3 nm for 2% and 5% WO3/TiO2, respectively. The SPA was evaluated on the degradation of commercial malathion pesticide using natural solar light. The 2% WO3/TiO2 photocatalyst exhibited the best photocatalytic activity achieving 76% of total organic carbon (TOC) abatement after 300 min compared to the 5% WO3/TiO2 and bare TiO2 photocatalysts, which achieved 28 and 47% mineralization, respectively. Finally, experiments were performed to assess 2% WO3/TiO2 catalyst activity on repeated uses; after several successive cycles its photocatalytic activity was retained showing long-term stability. PMID:23993423

Ramos-Delgado, N A; Gracia-Pinilla, M A; Maya-Treviño, L; Hinojosa-Reyes, L; Guzman-Mar, J L; Hernández-Ramírez, A

2013-12-15

201

Identification of degradation products of thiram in water, soil and plants using LCMS technique  

Microsoft Academic Search

In order to evaluate the deleterious effects of exposure to pesticides on a target population, a comprehensive study on their degradation in the various segments of ecosystem under varying environmental conditions is needed. In view of this, a study has been carried out on the metabolic pathways of thiram, a dithiocarbamate fungicide, in a variety of matrices namely water and

Bina Gupta; Manviri Rani; Rahul Kumar; Prem Dureja

2012-01-01

202

Sources and Input Pathways of Glyphosate and its Degradation Product AMPA  

NASA Astrophysics Data System (ADS)

Despite being the pesticide used in the largest quantities worldwide, the environmental relevance of glyphosate has been considered low for many years. Reasons for this assessment were the observations that glyphosate degrades quickly into its degradation product AMPA and that it sorbs strongly to soil particles. Hence, little losses to water bodies had been expected. Research during the last few years however contradicts this expectation. Although glyphosate is a dominant pesticide used in agriculture, recent studies on other pesticides revealed that urban sources may play a significant role for water quality. Therefore this study compares glyphosate input into streams from agricultural and urban sources. For that purpose, a catchment of an area of 25 km2 was selected. It has by about 12'000 inhabitants and about 15 % of the area is used as arable land. Four sampling sites were selected in the river system in order to reflect different urban and agricultural sources. Additionally, we sampled a combined sewer overflow, a rain sewer and the outflow of a waste water treatment plant. At each site discharge was measured continuously from March to November 2007. During 16 rain events samples were taken by automatic devices at a high temporal resolution. To analyze the concentration of glyphosate and its degradation product AMPA, the samples were derivatized with FMOC-Cl at low pH conditions and then filtrated. The solid phase extraction was conducted with Strata-X sorbent cartridge. Glyphosate and AMPA were detected with API 4000 after the chromatography with X bridge column C18. To assure the data quality, interne standards of Glyphosate and AMPA were added to every sample. The limit of detection and quantification for glyphosate and AMPA are bellow 1ng/l. We analyzed two rain events at a high resolution for all stations and several events at the outlet of the catchment. We measured high glyphosate concentration in urban and agriculture dominated catchments with up to 3'600ng/l in the rainwater sewer and 2'500ng/l from agricultural origin. The highest glyphosate concentrations were detected during peak flow. The input of the waste water treatment plant (WWTP) was up to 500ng/l. We detected glyphosate above the detection limit in all samples throughout the sampling period. Even after the vegetation period in November, glyphosate peak flow concentration in the outlet of the entire catchment was 137 ng/l exceeding the Swiss water quality criteria for single pesticides. The AMPA concentrations were generally lower than those of Glyphosate except for the WWTP. Generally, AMPA concentrations varied less during a rain event than glyphosate concentrations. Despite the strong sorption to soil particles and short half-life, glyphosate occurs in high concentrations in surface waters affected by urban and agricultural sources. Concentrations were even higher than those of other widely used herbicides like atrazine and mecoprop.

Bischofberger, S.; Hanke, I.; Wittmer, I.; Singer, H.; Stamm, C.

2009-04-01

203

Effect of fibrinogen degradation products on platelet aggregation  

PubMed Central

The digestion of fibrinogen with various concentrations of trypsin results in the formation of a variety of degradation products. Degradation products formed in this way have been purified by DEAE cellulose column chromatography and their effects on platelet aggregation investigated. Two methods have been used to study platelet aggregation: a turbidimetric method which assesses platelet aggregation by the ability of adenosine diphosphate (ADP) to clump platelets and a method which assesses platelet adhesiveness by their ability to adhere to glass and to each other (modified Hellem technique, 1960). Three breakdown products produced by trypsin-digested fibrinogen were studied and all showed `antithrombin' activity: two inhibited platelet aggregation, but one accelerated aggregation in both systems. Another product prepared by digestion of fibrinogen with urokinase-activated plasminogen has been shown to possess the ability to enhance ADP-induced platelet aggregation.

Wilson, Patricia A.; McNicol, G. P.; Douglas, A. S.

1968-01-01

204

Solvent degradation products in nuclear fuel processing solvents  

Microsoft Academic Search

The Savannah River Plant uses a modified Purex process to recover enriched uranium and separate fission products. This process uses 7.5% tri-n-butyl phosphate (TBP) dissolved in normal paraffin hydrocarbons for the solvent extraction of a nitric acid solution containing the materials to be separated. Periodic problems in product decontamination result from solvent degradation. A study to improve process efficiency has

Shook; H. E. Jr

1988-01-01

205

Neonicotinoid pesticide reduces bumble bee colony growth and queen production.  

PubMed

Growing evidence for declines in bee populations has caused great concern because of the valuable ecosystem services they provide. Neonicotinoid insecticides have been implicated in these declines because they occur at trace levels in the nectar and pollen of crop plants. We exposed colonies of the bumble bee Bombus terrestris in the laboratory to field-realistic levels of the neonicotinoid imidacloprid, then allowed them to develop naturally under field conditions. Treated colonies had a significantly reduced growth rate and suffered an 85% reduction in production of new queens compared with control colonies. Given the scale of use of neonicotinoids, we suggest that they may be having a considerable negative impact on wild bumble bee populations across the developed world. PMID:22461500

Whitehorn, Penelope R; O'Connor, Stephanie; Wackers, Felix L; Goulson, Dave

2012-04-20

206

Occurrence of Selected Pharmaceuticals, Personal-Care Products, Organic Wastewater Compounds, and Pesticides in the Lower Tallapoosa River Watershed near Montgomery, Alabama, 2005  

USGS Publications Warehouse

Synthetic and natural organic compounds derived from agricultural operations, residential development, and treated and untreated sanitary and industrial wastewater discharges can contribute contaminants to surface and ground waters. To determine the occurrence of these compounds in the lower Tallapoosa River watershed, Alabama, new laboratory methods were used that can detect human and veterinary antibiotics; pharmaceuticals; and compounds found in personal-care products, food additives, detergents and their metabolites, plasticizers, and other industrial and household products in the environment. Well-established methods for detecting 47 pesticides and 19 pesticide degradates also were used. In all, 186 different compounds were analyzed by using four analytical methods. The lower Tallapoosa River serves as the water-supply source for more than 100,000 customers of the Montgomery Water Works and Sanitary Sewer Board. Source-water protection is a high priority for the Board, which is responsible for providing safe drinking water. The U.S. Geological Survey, in cooperation with the Montgomery Water Works and Sanitary Sewer Board, conducted this study to provide baseline data that could be used to assess the effects of agriculture and residential development on the occurrence of selected organic compounds in the lower Tallapoosa River watershed. Twenty samples were collected at 10 sites on the Tallapoosa River and its tributaries. Ten samples were collected in April 2005 during high base streamflow, and 10 samples were collected in October 2005 when base streamflow was low. Thirty-two of 186 compounds were detected in the lower Tallapoosa River watershed. Thirteen compounds, including atrazine, 2-chloro-4-isopropylamino-6-amino-s-triazine (CIAT), hexazinone, metalaxyl, metolachlor, prometryn, prometon, simazine, azithromycin, oxytetracycline, sulfamethoxazole, trimethoprim, and tylosin, had measurable concentrations above their laboratory reporting levels. Concentrations were estimated for an additional 19 compounds that were detected below their laboratory reporting levels. The two most frequently detected compounds were the pesticides atrazine (19 of 20 samples) and simazine (13 of 20 samples). Tylosin, a veterinary antibiotic, was detected in 8 of 20 samples. Other compounds frequently detected at very low concentrations included CIAT and hexazinone (a degradate of atrazine and a pesticide, respectively); camphor (derived from personal-care products or flavorants), para-cresol (various uses including solvent, wood preservative, and in household cleaning products), and N,N-diethyl-m-toluamide (DEET, an insect repellent).

Oblinger, Carolyn J.; Gill, Amy C.; McPherson, Ann K.; Meyer, Michael T.; Furlong, Edward T.

2007-01-01

207

Pesticide use in banana and plantain production and risk perception among local actors in Talamanca, Costa Rica.  

PubMed

The Talamanca County in Costa Rica has large-scale banana and small-scale plantain production, probably causing pesticide exposure in indigenous children. We explored to what extent different community actors are aware of children's pesticide hazards and how their awareness related to socio-economical and cultural conditions. Methods comprised eight focus groups with fathers and mothers separately, 27 semi-structured interviews to key actors, and field observations. As a whole, the indigenous plantain farmers and banana plantation workers had some general knowledge of pesticides concerning crop protection, but little on acute health effects, and hardly any on exposure routes and pathways, and chronic effects. People expressed vague ideas about pesticide risks. Inter-community differences were related to pesticide technologies used in banana and plantain production, employment status on a multinational plantation versus smallholder status, and gender. Compared to formalized practices on transnational company plantations, where workers reported to feel protected, pesticide handling by plantain smallholders was not perceived as hazardous and therefore no safety precautions were applied. Large-scale monoculture was perceived as one of the most important problems leading to pesticide risks in Talamanca on banana plantations, and also on neighboring small plantain farms extending into large areas. Plantain farmers have adopted use of highly toxic pesticides following banana production, but in conditions of extreme poverty. Aerial spraying in banana plantations was considered by most social actors a major determinant of exposure for the population living nearby these plantations, including vulnerable children. We observed violations of legally established aerial spraying distances. Economic considerations were most mentioned as the underlying reason for the pesticide use: economic needs to obtain the production quantity and quality, and pressure to use pesticides by other economic agents such as middlemen. Risk perceptions were modulated by factors such as people's tasks and positions in the production process, gender, and people's possibilities to define their own social conditions (more fatalistic perceptions among banana workers). The challenge for the future is to combine these insights into improved health risk assessment and management that is culturally adequate for each particular community and agricultural context. PMID:21396636

Barraza, Douglas; Jansen, Kees; van Wendel de Joode, Berna; Wesseling, Catharina

2011-07-01

208

Study on retroaldol degradation products of antibiotic oligomycin A.  

PubMed

Studies of reactivity of antibiotic oligomycin A in various alkaline conditions showed that the compound easily undergoes retroaldol degradation in ?-hydroxy ketone fragments positioned in the C7-C13 moiety of the antibiotic molecule. Depending on reaction conditions, the retroaldol fragmentation of the 8,9 or 12,13 bonds or formation of a product through double retroaldol degradation, when the fragment C9-C12 was detached, took place followed by further transformations of the intermediate aldehydes formed. The structures of the obtained non-cyclic derivatives of oligomycin A were supported by NMR and MS methods. NMR parameters demonstrate the striking similarity of the geometry (conformation) of the fragment C20-C34 in the non-cyclic products of retroaldol degradation and the starting antibiotic 1. The compounds obtained had lower cytototoxic properties than oligomycin A for human leukemia cells K-562 and colon cancer cells HCT-116 and lower activity against growth inhibition of model object Streptomyces fradiae. It cannot be excluded that the products of retroaldol degradation participate in the biological effects of antibiotic oligomycin A. PMID:24084683

Lysenkova, Lyudmila N; Turchin, Konstantin F; Korolev, Alexander M; Danilenko, Valery N; Bekker, Olga B; Dezhenkova, Lyubov G; Shtil, Alexander A; Preobrazhenskaya, Maria N

2014-02-01

209

Are pesticide residues associated to rice production affecting oyster production in Delta del Ebro, NE Spain?  

PubMed

Pesticide usage in Delta del Ebro (NE Spain) during the rice growing season has been associated with oyster episodes of mortality that occur early in summer. However, there are no studies that have directly evaluated pesticide levels and effects in oysters (Crassotrea gigas) cultured in Ebro's Bays. In this study pesticide levels in water, metal body burdens and up to 12 different biochemical markers were monitored in gills and digestive glands of oysters transplanted from May to June in 2008 and 2009. Biochemical responses evidenced clear differences in oysters from 2008 and 2009. Oysters transplanted in 2009 showed their antioxidant defenses unaffected from May to June and consequently increased levels of tissue damage measured as lipid peroxidation and DNA strand breaks and of mortality rates. Conversely oysters transplanted in 2008 increase their antioxidant defenses from May to June, had low levels of lipid peroxidation and DNA damage and low mortality rates. Some pesticides in water such as bentazone and propanil together with high temperatures and salinity levels were related with tissue damage in oyster transplanted in 2008 but the observed large differences between years indicate that abiotic factors alone could not explain the high mortalities observed in 2009. An analysis of recent reported studies pointed out in the direction that in addition to abiotic factors the use of oysters sensitive to diseases may explain the observed responses. PMID:22940045

Ochoa, Victoria; Riva, Carmen; Faria, Melissa; Köck-Schulmeyer, Marianne; de Alda, Miren López; Barceló, Damià; Fernandez Tejedor, Margarita; Roque, Ana; Ginebreda, Antoni; Barata, Carlos

2012-10-15

210

Exploring the functional diversity of the supraglacial environment: Microbial degradation of the pesticide 2,4-D on the Greenland Ice Sheet  

NASA Astrophysics Data System (ADS)

The surface of the Greenland ice sheet (GrIS) harbours a diverse community of heterotrophic microorganisms. Organic compounds of anthropogenic origin, including pesticides, are deposited on the GrIS; however, the fate of these compounds in the ice is currently unknown. In this study we determine the potential of the microbial community from the surface of the GrIS to mineralise the pesticide 2,4-dichlorophenoxyacetic acid (2,4-D). It is one of the most easily degraded compounds among the phenoxyacetic acid pesticides, and the ability to mineralise 2,4-D has been found to be widespread in microbial communities around the globe. Functional genes involved in the degradation pathway have also been characterised. Thus, 2,4-D represents a very suitable model compound to use in order to gain an insight into pollutant degradation dynamics in the rapidly changing Arctic region. We collected surface ice cores on the GrIS and incubated them for up to 529 days in microcosms simulating in situ conditions. We measured mineralisation of side-chain- and ring-labelled 14C-2,4-D in the samples and performed quantitative PCR targeting the tfdA gene, encoding an enzyme catalysing the first step in the degradation pathway of 2,4-D, in the DNA extracted from the ice after the experiments. We show that the microbial community on the surface of the GrIS is of low diversity, but contains microbes capable of degrading 2,4-D. The low diversity of the community and the similarity of the detected clones to those from other icy environment clones suggest that the bacterial community on the GrIS is selected from a pool of propagules deposited on the surface of the ice sheet, based on the level of adaptation to the conditions in the surface ice. The 2,4-D degraders are likely present in very low numbers, and they can mineralise 2,4-D at a rate of up to 1 nmol per m2 per day, equivalent to ~26 ng C m-2 d-1. We contend that the surface of the GrIS should not be considered to be a mere reservoir of all atmospheric contaminants, as it is likely that some deposited compounds will be removed from the system via biodegradation processes before their potential release due to the accelerated melting of the ice sheet.

Stibal, M.; Bælum, J.; Holben, W. E.; Jacobsen, C. S.

2012-12-01

211

The Greening of Pesticide-Environment Interactions: Some Personal Observations  

PubMed Central

Background: Pesticide–environment interactions are bidirectional. The environment alters pesticides by metabolism and photodegradation, and pesticides in turn change the environment through nontarget or secondary effects. Objectives: Approximately 900 currently used commercial pesticides of widely diverse structures act by nearly a hundred mechanisms to control insects, weeds, and fungi, usually with minimal disruption of nature’s equilibrium. Here I consider some aspects of the discovery, development, and use of ecofriendly or green pesticides (i.e., pesticides that are safe, effective, and biodegradable with minimal adverse secondary effects on the environment). Emphasis is given to research in my laboratory. Discussion: The need for understanding and improving pesticide–environment interactions began with production of the first major insecticide approximately 150 years ago: The arsenical poison Paris Green was green in color but definitely not ecofriendly. Development and use of other pesticides has led to a variety of problems. Topics considered here include the need for high purity [e.g., hexachlorocyclohexane and polychloroborane isomers and 2,4,5-trichlorophenoxyacetic acid (2,4,5-T)], environmental degradation and the bioactivity of resulting photoproducts and metabolites, pesticide photochemistry (including the use of structural optimization, photostabilizers, and photosensitizers to achieve suitable persistence), the presence of multiple active ingredients in botanical insecticides, the need to consider compounds with common mechanisms of action, issues related to primary and secondary targets, and chemically induced or genetically modified changes in plant biochemistry. Many insecticides are bird, fish, and honeybee toxicants, whereas herbicides and fungicides pose fewer environmental problems. Conclusion: Six factors have contributed to the greening of pesticide–environment interactions: advances in pesticide chemistry and toxicology, banning of many chlorinated hydrocarbons, the development of new biochemical targets, increased reliance on genetically modified crops that reduce the amount and variety of pesticides applied, emphasis on biodegradability and environmental protection, and integrated pest- and pesticide-management systems.

2012-01-01

212

Pesticide bioconcentration modelling for fruit trees  

Microsoft Academic Search

The model presented allows simulating the pesticide concentration evolution in fruit trees and estimating the pesticide bioconcentration factor in fruits. Pesticides are non-ionic organic compounds that are degraded in soils cropped with woody species, fruit trees and other perennials. The model allows estimating the pesticide uptake by plants through the water transpiration stream and also the time in which maximum

Lourival Costa Paraíba

2007-01-01

213

Comparative responses of sperm cells and embryos of Pacific oyster (Crassostrea gigas) to exposure to metolachlor and its degradation products.  

PubMed

Metolachlor is one of the most intensively used chloroacetanilide herbicides in agriculture. Consequently, it has been frequently detected in coastal waters as well as its major degradation products, metolachlor ethane sulfonic acid (MESA) and metolachlor oxanilic acid (MOA) which are encountered at higher concentrations than metolachlor. Although a few studies of metolachlor toxicity have been conducted on marine organisms, little is known about the environmental toxicity of metolachlor degradation products. In this study, the deleterious effects of metolachlor and its degradation products on spermatozoa and embryos of Crassostrea gigas have been compared using biomarkers of developmental defects, DNA damage and gene transcription levels. After 24h exposure, significant increases in the percentage of abnormal D-larvae and DNA damage were observed from 0.01 ?g L(-1) for S-metolachlor and 0.1 ?g L(-1) for MESA and MOA. Results showed that S-metolachlor was more embryotoxic and genotoxic than its degradation products. Oyster sperm was also very sensitive to metolachlor exposure and followed the pattern: metolachlor (0.01 ?g L(-1))>MOA (0.1 ?g L(-1))>MESA (1 ?g L(-1)). Metolachlor and MESA mainly triggered variations in the transcription level of genes encoding proteins involved in oxidative stress responses (mitochondrial superoxide dismutase and catalase). Overall, no significant variation in transcription levels could be detected in C. gigas embryos exposed to MOA. This study demonstrates that metolachlor and its main degradation products have the potential to impact several steps of oyster development and therefore recruitment in coastal areas exposed to chronic inputs of pesticides. PMID:24378469

Mai, Huong; Gonzalez, Patrice; Pardon, Patrick; Tapie, Nathalie; Budzinski, Hélène; Cachot, Jérôme; Morin, Bénédicte

2014-02-01

214

Pesticide Assessment Guidelines Subdivision G: Product Performance Information Retrieval System (PAGIRS) (Single User) (for Microcomputers).  

National Technical Information Service (NTIS)

The Pesticide Assessment Guidelines Information Retrieval System (PAGIRS) provides the first comprehensive, electronic collection of U.S. Environmental Protection Agency (EPA) Pesticide Assessment Guidelines, their amendments and related EPA policy memora...

1995-01-01

215

Pesticide Assessment Guidelines Subdivision D: Product Chemistry Information Retrieval System (PAGIRS) (Single User) (for Microcomputers).  

National Technical Information Service (NTIS)

The Pesticide Assessment Guidelines Information Retrieval System (PAGIRS) provides the first comprehensive, electronic collection of U.S. Environmental Protection Agency (EPA) Pesticide Assessment Guidelines, their amendments and related EPA policy memora...

1995-01-01

216

Cadmium: Position Document 2/3. Notice of Preliminary Determination to Cancel Registrations and Deny Applications for All Pesticide Products that Contain Cadmium Compounds; Notice of Availability of Technical Support Document and Draft Notice of Intent to Cancel.  

National Technical Information Service (NTIS)

Cadmium compounds are contained as active ingredients in pesticides and fungicides. The Position Document addresses the risks and benefits of pesticide products containing the subject active ingredient. The Agency has determined that the use of products c...

1977-01-01

217

n-Propanol production during ethanol degradation using anaerobic granules  

Microsoft Academic Search

n-Propanol formation and consumption during ethanol oxidation by anaerobic brewery granules was investigated. The granules were taken from an UASB reactor fed with a synthetic brewery waste water. Ethanol degradation assays and an isotopic assay using 13C-labeled ethanol and bicarbonate were performed. Intermediate products propionate, n-propanol, acetate, hydrogen, formate and carbon monoxide were observed. Results have shown a consistent and

May M. Wu; Robert F. Hickey

1996-01-01

218

Surface detection of chemical warfare agent simulants and degradation products  

Microsoft Academic Search

Chemical warfare agent (CWA) simulants as well as their degradation and hydrolysis products were detected from surfaces using thermal desorption ion mobility spectrometry (TD-IMS). CWA simulant materials that closely mimic the chemical structures of real CWA G\\/V-type nerve and S-type vesicant simulants were used in this study. Reduced mobility constants (K0) in air were reported for 20 compounds studied. Spectra

Abu B. Kanu; Paul E. Haigh; Herbert H. Hill

2005-01-01

219

Normal phase LCMS determination of retinoic acid degradation products  

Microsoft Academic Search

The degradation products formed when 13-cis retinoic acid (13-cis RA) and all-trans RA were exposed to fluorescent light and air were investigated. These retinoids are known to undergo Z-E isomerization (due to the existence of four unsaturated double bonds) and oxidation when exposed to light and air. Analysis by LC was carried out on a 25 cm × 4.6 mm

Daniel K. Bempong; Irwin L. Honigberg; Noel M. Meltzer

1995-01-01

220

Overview of potential mutagenic problems posed by some pesticides and their trace impurities.  

PubMed Central

This review principally addresses a number of aspects of usage of pesticides as well as populations at potential risk and attempts to highlight categories of pesticides whose structures or those of their metabolites and/or trace impurities, degradation and transformation products suggest an a priori mutagenic and/or carcinogenic risk. The pesticides considered include: DDT, hexachlorobenzene (HCB), 2,4,5-T, pentachlorophenol, and various herbicidal precursors (e.g., carbamates, triazines) of nitrosamines and nitroso derivatives. Structural features of a number of halo-unsaturated pesticides (e.g., dichloropropenes) were also reviewed from a viewpoint of contrasting their potential mutagenicity with that of vinyl chloride and vinylidene chloride. Additionally the mutagenicity of the organophosphorus pesticide Trichlorophon is contrasted with that of its degradation products.

Fishbein, L

1978-01-01

221

The Occurrence of Chlorothalonil, its Transformation Products, and Selected Other Pesticides in Texas and Oklahoma Streams, 2003-2004  

NASA Astrophysics Data System (ADS)

The purpose of this study is to determine if the fungicide chlorothalonil (2,4,5,6-tetrachloro-isophthalonitrile) or three of its transformation products are transported to surface water after use on peanuts or other crops. Chlorothalonil is classified as a probable carcinogen, and the 4-hydroxy of chlorothalonil transformation product is more soluble, stable, and toxic than its parent compound. In 2003, 14 water samples were collected from three sites in Texas and two sites in Oklahoma. In 2004, six samples were collected from the two Oklahoma sites. Chlorothalonil was not detected in any sample. The 4-hydroxy of chlorothalonil transformation product was detected in three of the six samples collected in 2004, with a maximum concentration of 0.018 ?g/L; the other two transformation products were not detected in any sample. In addtion, samples were analyzed for as many as 109 other pesticides and transformation products. Atrazine was detected in 13 of the 19 samples with a maximum concentration of 0.122 ?g/L. Deethyatrazine was detected in 10 of the 19 samples with a maximum concentration of 0.04 ?g/L. Metolachlor was detected in 8 of the 19 samples with a maximum concentration of 0.019 ?g/L. Fifteen other pesticides or pesticide transformation products including 2,4-D, carbaryl, simazine, oryzalin, prometon, tebuthiuron were detected in four or fewer samples. In general, concentrations of pesticides were less than is commonly observed in Midwestern streams.

Battaglin, W. A.; Kuivila, K. M.; Winton, K. T.; Meyer, M. T.

2005-12-01

222

Effect of handling and processing on pesticide residues in food- a review.  

PubMed

Pesticides are one of the major inputs used for increasing agricultural productivity of crops. The pesticide residues, left to variable extent in the food materials after harvesting, are beyond the control of consumer and have deleterious effect on human health. The presence of pesticide residues is a major bottleneck in the international trade of food commodities. The localization of pesticides in foods varies with the nature of pesticide molecule, type and portion of food material and environmental factors. The food crops treated with pesticides invariably contain unpredictable amount of these chemicals, therefore, it becomes imperative to find out some alternatives for decontamination of foods. The washing with water or soaking in solutions of salt and some chemicals e.g. chlorine, chlorine dioxide, hydrogen peroxide, ozone, acetic acid, hydroxy peracetic acid, iprodione and detergents are reported to be highly effective in reducing the level of pesticides. Preparatory steps like peeling, trimming etc. remove the residues from outer portions. Various thermal processing treatments like pasteurization, blanching, boiling, cooking, steaming, canning, scrambling etc. have been found valuable in degradation of various pesticides depending upon the type of pesticide and length of treatment. Preservation techniques like drying or dehydration and concentration increase the pesticide content many folds due to concentration effect. Many other techniques like refining, fermentation and curing have been reported to affect the pesticide level in foods to varied extent. Milling, baking, wine making, malting and brewing resulted in lowering of pesticide residue level in the end products. Post harvest treatments and cold storage have also been found effective. Many of the decontamination techniques bring down the concentration of pesticides below MRL. However, the diminution effect depends upon the initial concentration at the time of harvest, substrate/food and type of pesticide. There is diversified information available in literature on the effect of preparation, processing and subsequent handling and storage of foods on pesticide residues which has been compiled in this article. PMID:24493878

Bajwa, Usha; Sandhu, Kulwant Singh

2014-02-01

223

ANALYTICAL METHOD DEVELOPMENT FOR ALACHLOR ESA AND OTHER ACETANILIDE HERBICIDE DEGRADATION PRODUCTS  

EPA Science Inventory

In 1998, USEPA published a Drinking Water Contaminant Candidate List (CCL) of 50 chemicals and 10 microorganisms. "Alachlor ESA and other acetanilide herbicide degradation products" is listed on the the 1998 CCL. Acetanilide degradation products are generally more water soluble...

224

DETERMINATION OF INTERFERING TRIAZINE DEGRADATION PRODUCTS BY GAS CHROMATOGRAPHY-ION TRAP MASS SPECTROMETRY  

EPA Science Inventory

Deethyl atrazine (DEA), along with other triazine degradation products, has been added to the US Environmental Protection Agency's Drinking Water Contaminant Candidate List (CCL). In its gas chromatographic (GC) analysis, deethyl atrazine, a degradation product of atrazine, can ...

225

Halotolerance, ligninase production and herbicide degradation ability of basidiomycetes strains.  

PubMed

Fungi have been recently recognized as organisms able to grow in presence of high salt concentration with halophilic and halotolerance properties and their ligninolytic enzyme complex have an unspecific action enabling their use to degradation of a number of xenobiotic compounds. In this work, both the effect of salt and polyols on growth of the basidiomycetes strains, on their ability to produce ligninolytic enzyme and diuron degradation were evaluated. Results showed that the presence of NaCl in the culture medium affected fungal specimens in different ways. Seven out of ten tested strains had growth inhibited by salt while Dacryopinax elegans SXS323, Polyporus sp MCA128 and Datronia stereoides MCA167 fungi exhibited higher biomass production in medium containing 0.5 and 0.6 mol.L(-1) of NaCl, suggesting to be halotolerant. Polyols such as glycerol and mannitol added into the culture media improved the biomass and ligninases production by D. elegans but the fungus did not reveal consumption of these polyols from media. This fungus degraded diuron in medium control, in presence of NaCl as well as polyols, produced MnP, LiP and laccase. PMID:24688513

Arakaki, R L; Monteiro, D A; Boscolo, M; Dasilva, R; Gomes, E

2013-12-01

226

Halotolerance, ligninase production and herbicide degradation ability of basidiomycetes strains  

PubMed Central

Fungi have been recently recognized as organisms able to grow in presence of high salt concentration with halophilic and halotolerance properties and their ligninolytic enzyme complex have an unspecific action enabling their use to degradation of a number of xenobiotic compounds. In this work, both the effect of salt and polyols on growth of the basidiomycetes strains, on their ability to produce ligninolytic enzyme and diuron degradation were evaluated. Results showed that the presence of NaCl in the culture medium affected fungal specimens in different ways. Seven out of ten tested strains had growth inhibited by salt while Dacryopinax elegans SXS323, Polyporus sp MCA128 and Datronia stereoides MCA167 fungi exhibited higher biomass production in medium containing 0.5 and 0.6 mol.L?1 of NaCl, suggesting to be halotolerant. Polyols such as glycerol and mannitol added into the culture media improved the biomass and ligninases production by D. elegans but the fungus did not reveal consumption of these polyols from media. This fungus degraded diuron in medium control, in presence of NaCl as well as polyols, produced MnP, LiP and laccase.

Arakaki, R.L.; Monteiro, D.A.; Boscolo, M.; Dasilva, R.; Gomes, E.

2013-01-01

227

Antimicrobial Pesticides  

NSDL National Science Digital Library

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

228

Pesticides use by smallholder farmers in vegetable production in Northern Tanzania.  

PubMed Central

Small-scale farmers in Northern Tanzania grow vegetables that include tomatoes, cabbages and onions and use many types of pesticides to control pests and diseases that attack these crops. Based on the use of questionnaires and interviews that were conducted in Arumeru, Monduli, Karatu, and Moshi rural districts, this study investigates farmers’ practices on vegetable pest management using pesticides and related cost and health effects. The types of pesticides used by the farmers in the study areas were insecticides (59%), fungicides (29%) and herbicides (10%) with the remaining 2% being rodenticides. About a third of the farmers applied pesticides in mixtures. Up to 90% had a maximum of 3 pesticides in a mixture. In all cases there were no specific instructions either from the labels or extension workers regarding these tank mixtures. Fifty three percent of the farmers reported that the trend of pesticide use was increasing, while 33% was constant and 14% was decreasing. More than 50 percent of the respondents applied pesticides up to 5 times or more per cropping season depending on the crop. Insecticides and fungicides were routinely applied by 77% and 7%, respectively by these farmers. Sixty eight percent of farmers reported having felt sick after routine application of pesticides. Pesticide-related health symptoms that were associated with pesticides use included skin problems and neurological system disturbances (dizziness, headache). Sixty one percent of farmers reported spending no money on health due to pesticides. These results can be used to develop a tool to quantify the cost of pesticide use in pest management by small-scale vegetable farmers in Northern Tanzania and contribute to the reformation of pesticide policy for safe and effective use of pesticides.

Ngowi, A.V.F.; Mbise, T.J.; Ijani, A.S.M.; London, L.; Ajayi, O. C.

2007-01-01

229

Structural elucidation of two photolytic degradation products of tetrabenazine.  

PubMed

During solution formulation study of tetrabenazine (TBZ), a dopamine depleting agent, used in chorea associated with Huntington's disease and symptomatic treatment of hyperkinetic movement disorder it was observed a strong discoloration upon storage. We investigated this physico-chemical behavior by implementing forced degradation studies. It was observed yellowing only under Suntest(®) light exposure of TBZ solution. LC-MS (liquid chromatography coupled to mass spectrometer detection) analysis of light exposed TBZ samples allowed us to propose 1,11b-dedihydrotetrabenazine (DTBZ) and 1,3,4,11b-detetrahydrotetrabenazine (TTBZ) as the main TBZ impurities. Synthesis and complete structural determination of DTBZ and TTBZ·HCl by NMR and X-ray crystallography were carried out. They were identical in LC-MS with polar impurities found in light exposed TBZ samples. However, even if these TBZ degradation products are correlated with discoloration of TBZ solution there is no evidence they are directly responsible of it. PMID:24457996

Bourezg, Zouaoui; Cartiser, Nathalie; Ettouati, Laurent; Guillon, Jean; Lacoudre, Aline; Pinaud, Noël; Le Borgne, Marc; Fessi, Hatem

2014-03-01

230

Enzymatic degradation of starch-based thermoplastic compounds used in protheses: identification of the degradation products in solution  

Microsoft Academic Search

Apart from favourable physico-chemical and mechanical properties, the most important requirement for a biodegradable polymer to be used in medical applications is its biocompatibility and the non-cytotoxicity of its degradation products. Their combined effect should assure the safe material degradation under controlled kinetics. The present work analyses the degradation behaviour of blends of corn starch with poly(ethylene-vinyl alcohol) copolymer (SEVA-C).

M Alberta Araújo; António M Cunha; Manuel Mota

2004-01-01

231

Molecular products from the thermal degradation of glutamic acid.  

PubMed

The thermal behavior of glutamic acid was investigated in N2 and 4% O2 in N2 under flow reactor conditions at a constant residence time of 0.2 s, within a total pyrolysis time of 3 min at 1 atm. The identification of the main pyrolysis products has been reported. Accordingly, the principal products for pyrolysis in order of decreasing abundance were succinimide, pyrrole, acetonitrile, and 2-pyrrolidone. For oxidative pyrolysis, the main products were succinimide, propiolactone, ethanol, and hydrogen cyanide. Whereas benzene, toluene, and a few low molecular weight hydrocarbons (propene, propane, 1-butene, and 2-butene) were detected during pyrolysis, no polycyclic aromatic hydrocarbons (PAHs) were detected. Oxidative pyrolysis yielded low molecular weight hydrocarbon products in trace amounts. The mechanistic channels describing the formation of the major product succinimide have been explored. The detection of succinimide (major product) and maleimide (minor product) from the thermal decomposition of glutamic acid has been reported for the first time in this study. Toxicological implications of some reaction products (HCN, acetonitrile, and acyrolnitrile), which are believed to form during heat treatment of food, tobacco burning, and drug processing, have been discussed in relation to the thermal degradation of glutamic acid. PMID:23875713

Kibet, Joshua K; Khachatryan, Lavrent; Dellinger, Barry

2013-08-14

232

Degradation of selected pesticide active ingredients and commercial formulations in water by the photo-assisted Fenton reaction  

Microsoft Academic Search

The destruction of pesticide active ingredients (AI) and commercial formulations in acidic aqueous solution with the catalytic photo-Fenton, Fe(III)\\/H2O2\\/UV, advanced oxidation process has been studied. The AI are alachlor, aldicarb, atrazine, azinphos-methyl, captan, carbofuran, dicamba, disulfoton, glyphosate, malathion, methoxylchlor, metolachlor, picloram and simazine. Complete loss of pure AI occurred in most cases in <30min under the following conditions: 5.0×10?5M Fe(III),

Patrick L Huston; Joseph J Pignatello

1999-01-01

233

Impact of pesticides on soil microbiological parameters and possible bioremediation strategies.  

PubMed

Intensive agriculture is spectacularly successful since last couple of decades due to the inputs viz; fertilizers and pesticides along with high yielding varieties. The mandate for agriculture development was to feed and adequate nutrition supply to the expanding population by side the agriculture would be entering to into new area of commercial and export orientation. The attention of public health and proper utilization natural resources are also the main issues related with agriculture development. Concern for pesticide contamination in the environment in the current context of pesticide use has assumed great importance [1]. The fate of the pesticides in the soil environment in respect of pest control efficacy, non-target organism exposure and offsite mobility has been given due consideration [2]. Kinetics and pathways of degradation depend on abiotic and biotic factors [6], which are specific to a particular pesticide and therefore find preference. Adverse effect of pesticidal chemicals on soil microorganisms [3], may affect soil fertility [4] becomes a foreign chemicals major issue. Soil microorganisms show an early warning about soil disturbances by foreign chemicals than any other parameters.But the fate and behavior of these chemicals in soil ecosystem is very important since they are degraded by various factors and have the potential to be in the soil, water etc. So it is indispensable to monitor the persistence, degradation of pesticides in soil and is also necessary to study the effect of pesticide on the soil quality or soil health by in depth studies on soil microbial activity.The removal of metabolites or degraded products should be removed from soil and it has now a day's primary concern to the environmentalist. Toxicity or the contamination of pesticides can be reduced by the bioremediation process which involves the uses of microbes or plants. Either they degrade or use the pesticides by various co metabolic processes. PMID:23100705

Chowdhury, Ashim; Pradhan, Saswati; Saha, Monidipta; Sanyal, Nilanjan

2008-03-01

234

Variation in pesticide hazard from arable crop production in Great Britain from 1992 to 2002: Pesticide risk indices and policy analysis  

Microsoft Academic Search

Attempts to direct policy according to scientific findings are hampered by the multidimensionality of the potential impacts of pesticides which may affect consumers, operators, wildlife and the environment. Pesticide risk indices seek to reduce these multidimensional impacts to a single dimension and are increasingly used to understand variation in the hazard inherent in pesticides at the farm, regional and national

Paul Cross; Gareth Edwards-Jones

2006-01-01

235

The investigation of the LED-activated FeFNS-TiO2 nanocatalyst for photocatalytic degradation and mineralization of organophosphate pesticides in water.  

PubMed

This study evaluated the preparation and characterization of an efficient doped TiO2 as a novel catalyst for degradation of diazinon model pesticide using LED-activated photocatalysis. TiO2 was doped using N, NS, FeNS, and FeFNS. The FeFNS-doped TiO2 showed the highest catalytic activity in LED/photocatalysis. FeFNS-doped TiO2 is a mesoporous nanocrystal powder with a mean pore diameter of 10.2 nm, a specific surface area of 104.4 m(2)/g and a crystallite size of 6.7 nm. LED/photocatalysis using FeFNS-doped TiO2 improved diazinon degradation by 52.3% over that of as-made plain TiO2 at an optimum solution pH of 7. The diazinon degradation in LED/photocatalysis using FeFNS-doped TiO2 increased from 44.8% to 96.3% when the catalyst concentration increased from 25% to 300%at a reaction time of 100 min. The degradation and mineralization of diazinon during LED/photocatalysis with FeFNS-doped TiO2 catalyst followed the pseudo-first-order reaction model with the rate constants of 0.973 h(-1) and 0.541 h(-1), respectively. The FeFNS-doped TiO2 was found to be an efficient catalyst that was photoactivated using UV-LED lamps. LED/photocatalysis with FeFNS-doped TiO2 catalyst is a promising alternative to conventional UV/TiO2photocatalysis for producing free OH radicals for use in the degradation and mineralization of water toxic contaminants. PMID:24793111

Hossaini, Hiwa; Moussavi, Gholamreza; Farrokhi, Mehrdad

2014-08-01

236

Multiresidue method for the fast determination of pesticides in nutraceutical products (Camellia sinensis) by GC coupled to triple quadrupole MS.  

PubMed

A method based on QuEChERS (quick, easy, cheap, effective, rugged, and safe) has been developed and validated for the determination and quantification of more than 140 pesticides in nutraceutical products obtained from green tea (Camellia sinensis). Extraction was performed with acidified acetonitrile (acetic acid 1%, v/v) and a clean-up step using primary secondary amine (50 mg), graphitized black carbon (100 mg) and magnesium sulfate (200 mg) was needed. Pesticide determination was achieved utilizing GC coupled to triple quadrupole MS/MS using the selective-reaction monitoring mode. The total run time was 23 min. Pesticides were quantified using matrix-matched calibration. Recoveries ranged from 70 to 120% and relative SD was lower than 25% at 10, 50, and 100 ?g/kg. LOQs were lower than 10 ?g/kg. 148 pesticides were validated. The validated method was applied to commercial nutraceutical products, detecting 4,4-dichlorobenzophenone (28 ?g/kg), o,p'-dicofol (38 ?g/kg) and p,p-dicofol (44 ?g/kg) in a few samples. PMID:24532456

Martínez-Domínguez, Gerardo; Plaza-Bolaños, Patricia; Romero-González, Roberto; Frenich, Antonia Garrido

2014-03-01

237

Selectivity of Pesticides used in Integrated Apple Production to the Lacewing, Chrysoperla externa  

PubMed Central

This research aimed to assess the toxicity of the pesticides abamectin 18 CE (0.02 g a.i. L-1), carbaryl 480 SC (1.73 g a.i. L-1), sulfur 800 GrDA (4.8 g a.i. L-1), fenitrothion 500 CE (0.75 g a.i. L-1), methidathion 400 CE (0.4 g a.i. L-1), and trichlorfon 500 SC (1.5 g a.i. L-1) as applied in integrated apple production in Brazil on the survival, oviposition capacity, and egg viability of the lacewing, Chrysoperla externa (Hagen) (Neuroptera: Chrysopidae) from Bento Gonçalves and Vacaria, Rio Grande do Sul State, Brazil. An attempt was made to study morphological changes caused by some of these chemicals, by means of ultrastructural analysis, using a scanning electronic microscope. Carbaryl, fenitrothion, and methidathion caused 100% adult mortality for both populations, avoiding evaluation of pesticides' effects on predator reproductive parameters. Abamectin and sulfur also affected the survival of these individuals with mortality rates of 10% and 6.7%, respectively, for adults from Bento Gonçalves, and were harmless to those from Vacaria at the end of evaluation. Trichlorfon was also harmless to adults from both populations. No compound reduced oviposition capacity. C. externa from Vacaria presented higher reproductive potential than those from Bento Gonçalves. In relation to egg viability, sulfur was the most damaging compound to both populations of C. externa. Ultrastructural analyses showed morphological changes in the micropyle and the chorion of eggs laid by C. externa treated with either abamectin or sulfur. The treatment may have influenced the fertilization of C. externa eggs and embryonic development. Sulfur was responsible for malformations in the end region of the abdomen and genitals of treated females. When applied to adults, abamectin, sulfur, and trichlorfon were harmless, while carbaryl, fenitrothion, and methidathion were harmful, according to the IOBC classification.

Moura, Alexandre Pinho; Carvalho, Geraldo Andrade; Moscardini, Valeria Fonseca; Lasmar, Olinto; Rezende, Denise Tourino; Marques, Marcio Candeias

2010-01-01

238

Liquid chromatography electrospray ionization tandem mass spectrometry study of nilutamide and its stress degradation products: in silico toxicity prediction of degradation products.  

PubMed

Nilutamide, a nonsteroidal anti-androgen drug, widely used in the treatment of prostate cancer, was subjected to hydrolytic, photolytic, thermal and oxidative stress conditions as per International Conference on Harmonization guidelines Q1A (R2). Nilutamide showed significant degradation under basic hydrolysis and photolytic stress conditions, while it was stable to neutral, acidic and thermal stress conditions. Five degradation products were formed and the chromatographic separation of nilutamide and its degradation products was achieved on a Waters C18 column (4.6?×?250?mm, 5?µm) using a mobile phase consisting of acetonitrile and 0.1% of formic acid in an isocratic elution method. All these degradation products were characterized by LC/MS/MS in negative ion mode, combined with accurate mass measurements. To assign likely structures for the observed degradation products, the fragmentation patterns of the deprotonated drug and its degradation products were compared. The in silico toxicity of the drug and its degradation products was also assessed using TOPKAT software. The carcinogenicity probability of the degradation products, DP-I-IV, was greater than that of nilutamide. Copyright © 2014 John Wiley & Sons, Ltd. PMID:24861745

Ramesh Babu, A; Borkar, Roshan M; Raju, G; Raju, B; Srinivas, R

2014-06-01

239

ESTIMATION OF EXPOSURE OF PERSONS IN CALIFORNIA TO PESTICIDE PRODUCTS THAT CONTAIN PROPETAMPHOS  

Microsoft Academic Search

Propetamphos is an organophosphate insecticide that is registered in California primarily for structural pest control. A total of 371 illnesses associated with the use of propetamphos alone or in combination with other pesticides have been reported in California from 1982 to 1993. The reported illnesses were predominantly for non-pesticide handlers, involving mostly office workers, restaurant workers, and residents reentering treated

Tareq A. Formoli

240

Pests, pesticide use and alternative options in European maize production: current status and future prospects  

Microsoft Academic Search

Political efforts are made in the European Union (EU) to reduce pesticide use and to increase the implementation of integrated pest management (IPM). Within the EU project ENDURE, research priorities on pesticide reduction are defined. Using maize, one of the most important crops in Europe, as a case study, we identified the most serious weeds, arthropod pests, and fungal diseases

M. Meissle; P. Mouron; T. Musa; Weide van der R. Y; J. A. M. Groten

2010-01-01

241

Induction of microglial reactive oxygen species production by the organochlorinated pesticide dieldrin  

Microsoft Academic Search

Exposure to pesticides has been speculated to contribute to the development of sporadic Parkinson's disease (PD) characterized by a progressive degeneration of the nigrostriatal dopaminergic pathway. Activation of brain microglia that produce various neurotoxic factors including cytokines and reactive oxygen species (ROS) has been increasingly associated with dopaminergic neurodegeneration induced by various toxicants. Dieldrin, a highly persistent organochlorinated pesticide found

Haoyu Mao; Xi Fang; Katon M. Floyd; Jeanette E. Polcz; Ping Zhang; Bin Liu

2007-01-01

242

Vascular responsiveness to dimethylaminoethyl methacrylate and its degradation products.  

PubMed

The increasing use of acrylate-based resins in dentistry has raised questions about the biocompatibility of these substances with oral tissues. The focus of the present investigation was to assess the responsiveness of blood vessels to the resin polymerization accelerating agent dimethylaminoethyl methacrylate (DMAEMA) and its degradation products dimethylethanolamine (DME) and methacrylic acid (MAA), using the rat aortic ring preparation as a tissue model. DMAEMA induced concentration-dependent relaxation of norepinephrine (NE)-contracted aortic rings with and without endothelium. N-nitro-L-arginine methyl ester (L-NAME) selectively inhibited the endothelium-dependent relaxation induced by DMAEMA, suggesting the release of nitric oxide from the endothelium by DMAEMA. Both indomethacin and glybenclamide attenuated the vasorelaxation elicited by DMAEMA in the presence as well as in the absence of endothelium, providing evidence for the role of vasorelaxant prostanoid(s) and K(ATP) channel activation in the responses observed. On the other hand, while MAA was without any apparent effect on the rat aorta, DMAEMA at high and DME at relatively low concentrations caused contraction of the tissues with and without endothelium in the absence of NE. The DME-induced contraction was inhibited by indomethacin, suggesting the involvement of contractile arachidonic acid metabolite(s) in the action of DME. This observation was supported by the findings of increased thromboxane A(2) (TXA(2)) production in aortic rings incubated with DME. Taken together, the data suggest that both DMAEMA and its degradation product, DME, are vasoactive, inducing vasorelaxation and contraction by various mechanisms that may involve the release of nitric oxide from the endothelium, the activation of smooth muscle K(ATP) channels, and the generation of vasorelaxant prostanoid(s) and TXA(2). These effects may play a role in tissue homeostasis and certain adverse conditions associated with the use of dental resin materials containing DMAEMA and/or DME. PMID:12833442

Abebe, Worku; Maddux, William F; Schuster, George S; Lewis, Jill B

2003-07-01

243

Enhanced enzymatic cellulose degradation by cellobiohydrolases via product removal.  

PubMed

Product inhibition by cellobiose decreases the rate of enzymatic cellulose degradation. The optimal reaction conditions for two Emericella (Aspergillus) nidulans-derived cellobiohydrolases I and II produced in Pichia pastoris were identified as CBHI: 52 °C, pH 4.5-6.5, and CBHII: 46 °C, pH 4.8. The optimum in a mixture of the two was 50 °C, pH 4.9. An almost fourfold increase in enzymatic hydrolysis yield was achieved with intermittent product removal of cellobiose with membrane filtration (2 kDa cut-off): The conversion of cotton cellulose after 72 h was ~19 % by weight, whereas the conversion in the parallel batch reaction was only ~5 % by weight. Also, a synergistic effect, achieving ~27 % substrate conversion, was obtained by addition of endo-1,4-?-D-glucanase. The synergistic effect was only obtained with product removal. By using pure, monoactive enzymes, the work illustrates the profound gains achievable by intermittent product removal during cellulose hydrolysis. PMID:23076365

Gavlighi, Hassan Ahmadi; Meyer, Anne S; Mikkelsen, J Dalgaard

2013-02-01

244

Gas-liquid chromatographic determination of nonpolar organochlorine pesticide residues in a crude vegetable oil and its refinery by-products.  

PubMed

A crude soybean oil, several of its refinery by-products (described as soapstock, deodorizer distillate, and clabber stock), and the completely refined oil were analyzed for pesticide residues. Fourteen organo-chlorine pesticides and pesticide metabolites were found in the deodorizer distillate; 5 of these were also found in the clabber stock. Levels in these by-products ranged from 0.3 to 8 ppm. Only endrin and dieldrin were detected in the crude oil at levels of 0.01 and 0.05 ppm, respectively. Forty to 150 times these levels were found in the deodorizer distillate and clabber stock. Pesticide residues were not detected in the refined oil or in the soapstock at limits of detection for dieldrin of about 0.01 and 0.1 ppm, respectively. The method used by the Food and Drug Administration to analyze fats and oils for multiple organohalogen pesticide residues was inadequate for the extraction of pesticide residues from vegetable oil refinery by-products. The method used to analyze the crude vegetable oil and the refinery by-products involved dissolution of the oil samples in ethyl acetate-toluene, filtration if necessary, cleanup by gel permeation chromatography, and then Florisil column chromatography. The oil was isolated from aqueous-oil mixtures by extraction with hexane before analysis. The crude soybean oil was fortified with 12 organohalogen pesticides and Aroclor 1254 at levels of 0.5-3.7 ppm. Recoveries ranged from 83 to 102%. PMID:6889594

Young, S J; Kamps, L R

1982-07-01

245

Guidance for the Reregistration of Manufacturing-Use and Certain End-Use Pesticide Products Containing Monuron-TCA (035502) as the Active Ingredient.  

National Technical Information Service (NTIS)

This document contains information regarding reregistration of pesticide products containing the subject active ingredient. The document includes how to register under a registration standard, regulatory position and rationale, and summaries of data requi...

1983-01-01

246

Toxicology of atmospheric degradation products of selected hydrochlorofluorocarbons  

NASA Technical Reports Server (NTRS)

Trifluoroacetic acid (TFA) is a liquid with a sharp biting odor. It has been proposed as the product of environmental degradation of the hydrochlorofluorocarbons HCFC-123, HCFC-124, HFC-134a, and HFC-125. Compounds HCFC-141b and HCFC-142b could yield mixed fluorochloroacetic acids, for which there is no available toxicologic data. The release of hydrochlorofluorocarbons into the environment could also give rise to HF, but the additional fluoride burden (1 to 3 ppb) in rainwater is trivial compared to levels in fluoridated drinking water (1 ppm), and would provide an insignificant risk to humans. Thus, in this paper only the toxocologic data on TFA is reviewed to assess the potential risks of environmental exposure.

Kaminsky, Laurence S.

1990-01-01

247

Relationship between bacterial diversity and function under biotic control: the soil pesticide degraders as a case study  

Microsoft Academic Search

In soil, the way biotic parameters impact the relationship between bacterial diversity and function is still unknown. To understand these interactions better, we used RNA-based stable-isotope probing to study the diversity of active atrazine-degrading bacteria in relation to atrazine degradation and to explore the impact of earthworm-soil engineering with respect to this relationship. Bulk soil, burrow linings and earthworm casts

Cécile Monard; Philippe Vandenkoornhuyse; Barbara Le Bot; Françoise Binet

2011-01-01

248

Seasonal exposures to triazine and other pesticides in surface waters in the western Highveld corn-production region in South Africa  

USGS Publications Warehouse

The objective of this study was to characterize concentrations of atrazine, terbuthylazine, and other pesticides in amphibian habitats in surface waters of a corn-production area of the western Highveld region (North-West Province) of South Africa. The study was conducted from November 2001 to June 2002, coinciding with the corn-production season. Pesticide residues were measured at regular intervals in surface water from eight ponds, three in a non-corn-growing area (NCGA) and five within the corn-growing area (CGA). Measured atrazine concentrations differed significantly among sites and between samples. In the five CGA sites, the maximum atrazine concentrations measured during the study ranged from 1.2 to 9.3 ??g/L. Although no atrazine was recorded as being applied in the catchment of the three NCGA sites, maximum concentrations from 0.39 to 0.84 ??g/L were measured during the study, possibly as a result of atmospheric transport. Maximum measured concentrations of terbuthylazine ranged from 1.22 to 2.1 ??g/L in the NCGA sites and from 1.04 to 4.1 ??g/L in the CGA sites. The source of terbuthylazine in the NCGA sites may have been in use other than in corn. The triazine degradation products, deisopropylatrazine (DIA) and deethylatrazine (DEA) and diaminochlorotriazine (DACT) were also found in water from both the CGA and NCGA sites. Concentrations of DIA were ??? 1 ??g/L throughout the season, while DEA concentrations were mostly 2 ??g/L in some locations. Concentrations of DACT were highly variable (LOD to 8 ??g/L) both before and after planting and application, suggesting that they resulted from historical use of triazines in the area. Other herbicides such as simazine and acetochlor were only detected infrequently and pesticides such as S-metolachlor, cypermethrin, monocrotophos, and terbuphos, known to be used in the CGA, were not detected in any of the samples. Because of dilution by higher than normal rainfall in the study period, these concentrations may not be predictive of those in years of normal rainfall. ?? 2004 Elsevier Ltd. All rights reserved.

Du, Preez, L. H.; Jansen, Van Rensburg, P. J.; Jooste, A. M.; Carr, J. A.; Giesy, J. P.; Gross, T. S.; Kendall, R. J.; Smith, E. E.; Van Der Kraak, G.; Solomon, K. R.

2005-01-01

249

Identification of the product of Toxoflavin lyase: degradation via a Baeyer-Villiger oxidation  

PubMed Central

Toxoflavin (an azapteridine) is degraded to a single product by toxoflavin lyase (TflA) in a reaction dependent on reductant, Mn(II), and oxygen. The isolated product was fully characterized by NMR and MS and was identified as a triazine in which the pyrimidine ring was oxidatively degraded. A mechanism for toxoflavin degradation based on the identification of the enzymatic product and the recently determined crystal structure of toxoflavin lyase is proposed.

Philmus, Benjamin; Abdelwahed, Sameh; Williams, Howard J.; Fenwick, Michael K.; Ealick, Steven E.; Begley, Tadhg P.

2012-01-01

250

Metabolism of Glyoxylate, the End Product of Purin Degradation, in Liver Peroxisomes of Fresh Water Fish  

Microsoft Academic Search

In marine fish liver, degradative enzymes able to convert purines to urate have been shown to be located in the cytosol and degradative enzymes able to convert urate to urea and glyoxylate in the peroxisomes. The end products of purine degradation are urea and glyoxylate in fish. Glyoxylate may be converted to glycine by alanine:glyoxylate aminotransferase for the reutilization of

Haruhiko Sakuraba; Satoko Fujiwara; Tomoo Noguchi

1996-01-01

251

Tyramine degradation and tyramine\\/histamine production by lactic acid bacteria and Kocuria strains  

Microsoft Academic Search

Of 53 strains of lactic acid bacteria and Kocuria, screened for production or degradation of biogenic amines, 29 Kocuria varians and four strains of Enterococcusfaecalisproduced tyramine and, at lower concentrations, histamine. In contrast, Lactobacillus strains that did not possess amino acid decarboxylase activity degraded tyramine. The greatest tyramine oxidase activity was present in the strains L. casei CRL705 (98% degradation)

S. Fadda; G. Vignolo; G. Oliver

2001-01-01

252

78 FR 72879 - Product Cancellation Order for Certain Pesticide Registrations; Correction  

Federal Register 2010, 2011, 2012, 2013

...cancellation order notice. FOR FURTHER INFORMATION CONTACT: John W. Pates, Jr., Pesticide Re- Evaluation Division (7508P), Office...20460-0001; telephone number: (703) 308-8195; email address: pates.john@epa.gov. SUPPLEMENTARY INFORMATION: I....

2013-12-04

253

75 FR 20842 - Pirimicarb; Product Cancellation Order for Certain Pesticide Registrations  

Federal Register 2010, 2011, 2012, 2013

...effective April 21, 2010. FOR FURTHER INFORMATION CONTACT: Olga Odiott, Registration Division, Office of Pesticide Programs...fax number: (703) 305-6920; e-mail address: odiott.olga@epa.gov. SUPPLEMENTARY INFORMATION: [[Page...

2010-04-21

254

76 FR 41178 - Pesticides; Policies Concerning Products Containing Nanoscale Materials; Opportunity for Public...  

Federal Register 2010, 2011, 2012, 2013

...under FOR FURTHER INFORMATION CONTACT. List of Subjects Environmental protection, Administrative practice and procedure, Nanotechnology, Pesticides and pests. Dated: July 6, 2011. William R. Diamond, Acting Assistant Administrator, Office of...

2011-07-13

255

Biodegradation of high molecular weight lignin under sulfate reducing conditions: lignin degradability and degradation by-products.  

PubMed

This study is designed to investigate the biodegradation of high molecular weight (HMW) lignin under sulfate reducing conditions. With a continuously mesophilic operated reactor in the presence of co-substrates of cellulose, the changes in HMW lignin concentration and chemical structure were analyzed. The acid precipitable polymeric lignin (APPL) and lignin monomers, which are known as degradation by-products, were isolated and detected. The results showed that HMW lignin decreased and showed a maximum degradation capacity of 3.49 mg/l/day. APPL was confirmed as a polymeric degradation by-product and was accumulated in accordance with HMW lignin reduction. We also observed non-linear accumulation of aromatic lignin monomers such as hydrocinnamic acid. Through our experimental results, it was determined that HMW lignin, when provided with a co-substrate of cellulose, is biodegraded through production of APPL and aromatic monomers under anaerobic sulfate reducing conditions with a co-substrate of cellulose. PMID:18977138

Ko, Jae-Jung; Shimizu, Yoshihisa; Ikeda, Kazuhiro; Kim, Seog-Ku; Park, Chul-Hwi; Matsui, Saburo

2009-02-01

256

Advances in pesticide environmental fate and exposure assessments.  

PubMed

Globalization of markets and the growing world population increase threats of invasive and exotic species and place greater demands on food and fiber production. Pest management in both agricultural and nonagricultural settings employs established practices and new biological, chemical, and management technologies. Pesticides are an essential tool in integrated pest management. Without pesticides a significant percentage of food and fiber crops would be lost, infectious diseases would increase, and valuable native habitats would be devastated. Therefore, it is important to understand the environmental fate of pesticides and assess their potential exposure and associated risks to human health and the environment. This paper summarizes the Advances in Pesticide Environmental Fate and Exposure Assessment symposium held at the 231st National Meeting of the American Chemical Society (Atlanta, GA, 2006). The focus of the symposium was to provide current information on advances in pesticide environmental fate and exposure assessments. Thirty papers were presented on advances ranging from subcellular processes to watershed-scale studies on topics including chemical degradation, sorption, and transport; improved methodologies; use of modeling and predictive tools; exposure assessment; and treatment and remediation. This information is necessary to develop more effective pesticide use and management practices, to better understand pesticide fate and associated exposures and risks, to develop mitigation and remediation strategies, and to establish sound science-based regulations. PMID:17552539

Rice, Pamela J; Rice, Patricia J; Arthur, Ellen L; Barefoot, Aldos C

2007-07-11

257

Detection of Pesticides and Pesticide Metabolites Using the Cross Reactivity of Enzyme Immunoassays  

USGS Publications Warehouse

Enzyme immunoassay is an important environmental analysis method that may be used to identify many pesticide analytes in water samples. Because of similarities in chemical structure between various members of a pesticide class, there often may be an unwanted response that is characterized by a percentage of cross reactivity. Also, there may be cross reactivity caused by degradation products of the target analyte that may be present in the sample. In this paper, the concept of cross reactivity caused by degradation products or by nontarget analytes is explored as a tool for identification of metabolites or structurally similar compounds not previously known to be present in water samples. Two examples are examined in this paper from various water quality studies. They are alachlor and its metabolite, alachlor ethane sulfonic acid, and atrazine and its class members, prometryn and propazine. A method for using cross reactivity for the detection of these compounds is explained in this paper.

Thurman, E. M.; Aga, D. S.

2001-01-01

258

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

USGS Publications Warehouse

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

259

Long-term clinical effects of a peritoneal dialysis fluid with less glucose degradation products  

Microsoft Academic Search

Long-term clinical effects of a peritoneal dialysis fluid with less glucose degradation products.BackgroundGlucose degradation products (GDPs) are cytotoxic in vitro and potentially toxic in vivo during peritoneal dialysis (PD). We are presenting the results of a two-year randomized clinical trial of a new PD fluid, produced in a two-compartment bag and designed to minimize heat-induced glucose degradation while producing a

Bengt Rippe; Ole Simonsen; Olle Heimbürger; Anders Christensson; Börje Haraldsson; Gunnar Stelin; Lars Weiss; Finn-David Nielsen; Susanne Bro; Michael Friedberg; Anders Wieslander

2001-01-01

260

[Screening method for the determination of 199 pesticides in agricultural products by gas chromatography/ion trap mass spectrometry (GC/MS/MS)].  

PubMed

A screening method is described for determining 200 pesticides, except dimethipin, divided into four groups by means of gas chromatography/tandem mass spectrometry (GC/MS/MS) using an ion trap mass spectrometer equipped with automated gain control (AGC). The quantitation limit for 194 pesticides was 0.01 mg/kg on a crop basis, except for allidochlor, dimethoate, hexythiazox, methamidophos and triadimenol. The calibration curve of each pesticide was linear in the range of 0.04-5.0 microg/mL. One hundred and ninety-nine pesticides were added to matrix of potato, spinach, cabbage, apple, orange, soybean and unpolished rice at twice the limits of quantitation. The recoveries of 194 pesticides from all crops were satisfactory (50-150%) for screening purposes. Although some pesticides in apple and orange were not determined by selected ion monitoring (SIM) analysis at the limits of quantitation, all of them were identified by ion-trap GC/MS/MS at the same concentration. Thus, the ion trap GC/MS/MS technique is useful for the screening of residual pesticides present at low levels in agricultural products. PMID:17128871

Hirahara, Yoshichika; Kimura, Mika; Inoue, Tomoko; Uchikawa, Seiji; Otani, Shoji; Hirose, Hideaki; Suzuki, Sosuke; Uchida, Yukinori

2006-10-01

261

Degradation Product Analysis for Polymeric Dielectric Materials Exposed to Partial Discharges  

Microsoft Academic Search

Partial discharge phenomena appear to play an important role in insulation failure, and thus the analysis of products resulting from such degradation may lead to an understanding of insulation breakdown mechanisms and more accurate determination of insulation lifetimes. Progress in the area of degradation product analysis is reviewed for solid and liquid insulating materials.

Kevin D. Wolter; Julian F. Johnson; John Tanaka

1978-01-01

262

Mechanism of thermal decomposition of a pesticide for safety concerns: Case of Mancozeb  

Microsoft Academic Search

Thermal decomposition under both air and inert atmospheres of a commercial Mancozeb product was investigated through thermogravimetric analysis and laboratory scale thermal treatment from 20°C to 950°C, with analysis of gaseous and solid products. The aim of this study is the understanding of the thermal degradation mechanisms of a pesticide under different atmospheres and the chemical identification of the solid

N. Giroud; S. Dorge; G. Trouvé

2010-01-01

263

Pesticide exposure--Indian scene.  

PubMed

Use of pesticides in India began in 1948 when DDT was imported for malaria control and BHC for locust control. India started pesticide production with manufacturing plant for DDT and benzene hexachloride (BHC) (HCH) in the year 1952. In 1958, India was producing over 5000 metric tonnes of pesticides. Currently, there are approximately 145 pesticides registered for use, and production has increased to approximately 85,000 metric tonnes. Rampant use of these chemicals has given rise to several short-term and long-term adverse effects of these chemicals. The first report of poisoning due to pesticides in India came from Kerala in 1958 where, over 100 people died after consuming wheat flour contaminated with parathion. Subsequently several cases of pesticide-poisoning including the Bhopal disaster have been reported. Despite the fact that the consumption of pesticides in India is still very low, about 0.5 kg/ha of pesticides against 6.60 and 12.0 kg/ha in Korea and Japan, respectively, there has been a widespread contamination of food commodities with pesticide residues, basically due to non-judicious use of pesticides. In India, 51% of food commodities are contaminated with pesticide residues and out of these, 20% have pesticides residues above the maximum residue level values on a worldwide basis. It has been observed that their long-term, low-dose exposure are increasingly linked to human health effects such as immune-suppression, hormone disruption, diminished intelligence, reproductive abnormalities, and cancer. In this light, problems of pesticide safety, regulation of pesticide use, use of biotechnology, and biopesticides, and use of pesticides obtained from natural plant sources such as neem extracts are some of the future strategies for minimizing human exposure to pesticides. PMID:15138033

Gupta, P K

2004-05-20

264

Evaluation of serum pesticide residue levels and liver function in persons exposed to dairy products contaminated with heptachlor  

SciTech Connect

The authors studied a group of 45 dairy farm family members who had consumed undiluted raw milk products known to be contaminated with residues of the pesticide heptachlor at concentrations as high as 89.2 ppm (fat basis). They compared results of serum pesticide assays for these exposed persons with results for an unexposed group of 94 persons from the same geographic area and the results from the Second National Health and Nutrition Examination Survey. The exposed group had significantly higher mean levels of primary heptachlor metabolites-i.e., heptachlor epoxide and oxychlordane than the unexposed group. In the exposed group, 21.2% had evaluated serum concentrations of these same metabolites; this rate was significantly greater than the rates in both the unexposed farm family members (heptachlor epoxide, 3.8%; oxychlordane, 6.3%) and the Second National Health and Nutrition Examination Survey sample (2.5% for both metabolites). However they found no evidence of related acute and/or subacute hepatic effects in these exposed persons regardless of their serum concentrations of pesticide residues.

Stehr-Green, P.A.; Wohlleb, J.C.; Royce, W.; Head, S.L.

1988-01-15

265

Identification of degradation products of diclofenac by electrospray ion trap mass spectrometry.  

PubMed

The degradation products of diclofenac in aqueous dosage form in accelerated storage conditions were characterized by electrospray ionization-ion trap mass spectrometry (ESI-MS). Liquid chromatography (LC)-MS analyses revealed the presence of three degradation products. ESI-MS(n) spectra were used to study diclofenac fragmentation in detail and to characterize the structures of degradation products. A previously described degradation product, formed by a cyclization reaction of diclofenac producing the indolinone derivative, was found. As any hydroxylated product was found, no oxidation seems to occur in the dosage form used. On the contrary, two degradates have been detected and identified, leading to a primary alcohol structure or an aldehyde function in place of the acetate group of diclofenac. PMID:15967311

Galmier, Marie-Josèphe; Bouchon, Bernadette; Madelmont, Jean-Claude; Mercier, Fabrice; Pilotaz, Frédéric; Lartigue, Claire

2005-07-15

266

[Applicability of GC, GC/MS and liquid chromatography with tandem mass spectrometry to screening for 140 pesticides in agricultural products].  

PubMed

The applicability of GC, GC/MS and liquid chromatography with tandem mass spectrometry (LC/MS/MS) to screening for 140 pesticides in agricultural products was examined. Validation of multi-residue screening methods for the determination of 88 pesticides in 12 crops (asparagus, cauliflower, burdock, carrot, broccoli, spinach, matsutake mushroom, orange, soybean, sesame, millet and tea) was done by GC and GC/MS. Of the 88 pesticides, 63 were obtained with recoveries in the range from 50 to 150% at the 0.1 microg/g level in the 12 crops. Applicability of the official methods in Japan to 74 pesticides, including 22 pesticides with low recovery (< 50%) by GC or GC/MS analysis, was also examined by LC/MS/MS. LC/MS/MS acquisition parameters were established for 67 pesticides in positive and negative electrospray ionization (ESI) modes. Of 67 pesticides validated in 7 crops using LC/MS/MS at the 0.1 microg/g level, 44 showed recoveries in the range from 50 to 150%. The occurrence of matrix interference in LC/MS/MS can lead to false-positive detection of MCPA in spinach, cabbage and orange and false-negative detection of four pesticides in orange, spinach, apple and unpolished rice. Good linearity was observed in the studied ranges by GC, GC/MS (r > 0.990) and LC/MS/MS (r > 0.995). Of the total of 140 pesticides validated by GC, GC/MS and LC/MS/MS, 107 were newly recognized as suitable subjects for screening. PMID:17128873

Hirahara, Yoshichika; Kimura, Mika; Inoue, Tomoko; Uchikawa, Seiji; Otani, Shoji; Hirose, Hideaki; Suzuki, Sosuke; Uchida, Yukinori

2006-10-01

267

Investigation of sorbic acid volatile degradation products in pharmaceutical formulations using static headspace gas chromatography.  

PubMed

An analytical method that allows simultaneous analysis of sorbic acid and its degradation products was developed using static headspace gas chromatography (HS-GC). AT-Aquawax-DA, the capillary column used, showed good selectivity and separation towards sorbic acid and its degradation products. Sorbic acid degradation was investigated in both acidic and aqueous media at room and elevated temperatures. In total 12 sorbic acid degradation products were found, 8 of which could be characterized. The method was investigated for its accuracy towards estimation of degradation products. Using the HS-GC method different batches of pharmaceutical preparations such as cold cream, cetomacrogol cream and vaseline were investigated for sorbic acid degradation products which were estimated by applying the standard addition method. Acetaldehyde was found to be the major degradation product. The other identified degradation products were: acetone; 2-methylfuran; crotonaldehyde; alfa-angelicalactone; 2-acetyl, 5-methylfuran; toluene and 2,5-dimethylfuran. Both mass spectrometeric (MS) and flame ionization detection (FID) were used. The qualitative investigation was done on HS-GC-MS and the quantitative work on HS-GC-FID. PMID:17306494

Yarramraju, Sitaramaraju; Akurathi, Vamsidhar; Wolfs, Kris; Van Schepdael, Ann; Hoogmartens, Jos; Adams, Erwin

2007-06-28

268

Selective determination of ertapenem in the presence of its degradation product  

NASA Astrophysics Data System (ADS)

Stability-indicative determination of ertapenem (ERTM) in the presence of its ?-lactam open-ring degradation product, which is also the metabolite, is investigated. The degradation product has been isolated, via acid-degradation, characterized and elucidated. Selective quantification of ERTM, singly in bulk form, pharmaceutical formulations and/or in the presence of its major degradant is demonstrated. The indication of stability has been undertaken under conditions likely to be expected at normal storage conditions. Among the spectrophotometric methods adopted for quantification are first derivative ( 1D), first derivative of ratio spectra ( 1DD) and bivariate analysis.

Hassan, Nagiba Y.; Abdel-Moety, Ezzat M.; Elragehy, Nariman A.; Rezk, Mamdouh R.

2009-06-01

269

Metolachlor: Pesticide Registration Standards.  

National Technical Information Service (NTIS)

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

1980-01-01

270

Characteristics and kinetics of catalpol degradation and the effect of its degradation products on free radical scavenging  

PubMed Central

Background: The dried and steamed roots of Rehmannia glutinosa have different pharmacological functions and indications. Catalpol, the main active component of the dried root, was found to be entirely degraded together with amino acids and some oligosaccharides during preparation of the steamed root. Its degradation may contribute to the differences between dried and steamed roots. Objective: To reveal the characteristics and kinetics of catalpol degradation, and evaluate its influence on the antioxidant properties of steamed Rehmannia roots. Materials and Methods: Purified catalpol was heated under different pH and temperature values for different times, alone or with sugars or amino acids. Catalpol concentration was determined by high-performance liquid chromatography. Browning was expressed by the absorbance at 420 nm (A420), and antioxidation was displayed by 2,2-diphenyl-1-picrylhydrazyl free radical scavenging ability (SADPPH). Activation energy was calculated using Arrhenius plotting. Results: Catalpol was stable in neutral conditions and sensitive to acidic pH under high temperatures. Sugars had no influence on catalpol degradation; however, most amino acids, except for proline, could promote the degradation, and were associated with an increase in A420 and SADPPH values. These changes were proved to be mainly related with catalpol aglycone and were dependent on the presence of amino acids. Catalpol degradation was found to obey first-order kinetics. The activation energies were 81.7, 88.8 and 98.7 kJ/mol at pH 4.0, 5.0, and 6.0 respectively, and 70.7 kJ/mol at pH 4.0 value and in the presence of glycine. Conclusions: Catalpol degradation, especially, in the presence of amino acids can substantially boost antioxidant properties of the products; therefore, the traditional method for processing Rehmannia root seems rather apt.

Wei, Guo-dong; Wen, Xue-sen

2014-01-01

271

DETECTION OF MUTAGENIC PROPERTIES OF PESTICIDES USED IN COMMERCIAL CORN PRODUCTION  

EPA Science Inventory

This project encompassed the analysis of 21 pesticides and 12 combinations of herbicides for their genotoxic properties. Three genetic assays were employed: reverse mutation in Salmonella typhimurium, gene conversion in S. cerveisiae and reverse mutation in Z. mays. The use of th...

272

Sublethal Effects of Three Pesticides on Larval Survivorship, Growth, and Macromolecule Production in the Aquatic Midge, Chironomus tentans (Diptera: Chironomidae)  

Microsoft Academic Search

Effects of long-term exposure to each of three pesticides including atrazine, DDT, and chlorpyrifos on larval survivorship,\\u000a growth, and macromolecule (total body protein and RNA) production were evaluated in the aquatic midge, Chironomus tentans, under laboratory conditions. Newly hatched larvae were exposed to atrazine at 30 and 150 ?g\\/L, DDT at 0.01 and 0.05 ?g\\/L,\\u000a or chlorpyrifos at 0.02 and 0.10 ?g\\/L throughout

Mamy L. Rakotondravelo; Troy D. Anderson; Ralph E. Charlton; Kun Yan Zhu

2006-01-01

273

Soil column leaching of pesticides.  

PubMed

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

274

Persistence of selected pesticides and their phenolic transformation products in natural waters using off-line liquid solid extraction followed by liquid chromatographic techniques  

Microsoft Academic Search

The degradation of three organophosphorus pesticides with phenolic type structure (fenitrothion, ethyl-parathion, methylparathion) and pentachlorophenol in natural waters from Porto (Portugal) was studied. Three different types of natural waters (river water, estuarine water and ground water) were spiked with ethyl-parathion, methyl-parathion, fenitrothion and pentachlorophenol at 40 ?g\\/l level and were exposed outdoor to ambient sunlight and temperature in natural conditions

M. Castillo; R. Domingues; M. F. Alpendurada; D. Barceló

1997-01-01

275

Pesticide application practices, pest knowledge, and cost-benefits of plantain production in the Bribri-Cabécar Indigenous Territories, Costa Rica  

Microsoft Academic Search

The use of pesticides in the cultivation of cash crops such as banana and plantain is increasing, in Costa Rica and worldwide. Agrochemical use and occupational and environmental exposures in export banana production have been documented in some parts of Central America. However, the extent of agrochemical use, agricultural pest knowledge, and economic components in plantain production are largely unknown

Beth A. Polidoro; Ruth M. Dahlquist; Luisa E. Castillo; Matthew J. Morra; Eduardo Somarriba; Nilsa A. Bosque-Pérez

2008-01-01

276

A stability indicating HPLC method for the determination of clobazam and its basic degradation product characterization  

PubMed Central

Background Clobazam is used for the treatment of different types of seizure and epilepsy. The present research is undertaken to study the systematic forced degradation of clobazam and to identify its main degradation product under basic conditions. Methods The degradation of clobazam was studied under different conditions. Clobazam and its degradation products were separated using a Nova-Pak C18 column and a mixture of KH2PO4 50 mM (pH 8.5) and acetonitrile (50:50, v/v) as the mobile phase with UV detection at 230 nm. Results The within-day and between-day precision values in the calibration range of 0.1-20 ?g/ml were within 0.5-1.5%. Clobazam was relatively stable in solid from under exposure to visible and UV light and also heat. The clobazam aqueous solution of clobazam was more labile under exposure to visible and UV light. The bulk drug was significantly degraded under exposure to 2 M HCl, 0.1 M NaOH or 3% H2O2. Using the tablet powder, higher degradation rates were observed under different stress conditions. The main degradation product of clobazam under basic condition was subsequently characterized. Conclusion The developed method could be used for the determination of clobazam in the presence of its degradation products with acceptable precision and accuracy. The applicability of the proposed method was evaluated in commercial dosage forms analysis.

2014-01-01

277

CHEMICAL NATURE AND IMMUNOTOXICOLOGICAL PROPERTIES OF ARACHIDONIC ACID DEGRADATION PRODUCTS FORMED BY EXPOSURE TO OZONE  

EPA Science Inventory

Ozone (O3) exposure in vivo has been reported to degrade arachidonic acid (AA) in the lungs of rodents. The O3-degraded AA products may play a role in the lung responses to this toxicant. In order to study the chemical nature and biological activity of O3-exposed AA, we exposed A...

278

Products of anaerobic phloroglucinol degradation by Coprococcus sp. Pe15.  

PubMed

Under anaerobic conditions, resting cell suspensions of Coprococcus sp. Pe15 degraded 1 molecule of phloroglucinol to 2 molecules of acetic acid and 2 molecules of carbon dioxide. The organism metabolized the flavonoids rhamnetin and quercetin anaerobically in 20% rumen fluid medium but failed to grow under similar conditions at the expense of any of 39 other aromatic or flavonoid compounds tested. PMID:944077

Tsai, C G; Gates, D M; Ingledew, W M; Jones, G A

1976-02-01

279

METHOXYCHLOR AND DDT DEGRADATION IN WATER: RATES AND PRODUCTS  

EPA Science Inventory

Methoxychlor (2,2-bis(methoxyphenyl)-1,1,1-trichloroethane) and DDT (2,2-bis(chlorophenyl)-1,1,1-trichloroethane) undergo different hydrolytic degradation pathways in water at pH's common to the aquatic environment. For methoxychlor at common aquatic pH's, the reaction is pH inde...

280

Electrochemical biosensors for rapid determination of pesticide residues in agricultural products  

NASA Astrophysics Data System (ADS)

The biosensors, consisting of immobilized antibodies which were for specific recognition to target molecules and electrodes which were able to convert the binding event between antigen and antibody to a detectable signal, were developed for rapid detection of organophosphate (OPs) pesticides. Anti-OPs antibodies were immobilized onto indium-tin-oxide (ITO) coated interdigitated microsensor electrodes (IMEs). The Faradaic impedance spectra, presented as Nyquist plots (Z' vs Z'') and Bode diagrams, (impedance vs frequency) were recorded in the frequency range from 1Hz to 100 kHz respectively. A linear relationship between the electron-transfer resistance and concentrations of OPs pesticide was found ranging from 0.1 ppm to 100 ppm. The regression equations were Y = 658 X +1861, with the correlation coefficient of 0.977. The biosensing procedure was simple and rapid, and could be completed within 1 h.

Jiang, Xuesong; Wang, Jianping; Ying, Yibin; Ye, Zunzhong; Li, Yanbin

2005-11-01

281

Methods of Analysis by the U.S. Geological Survey National Water Quality Laboratory - Determination of Moderate-Use Pesticides and Selected Degradates in Water by C-18 Solid-Phase Extraction and Gas Chromatography/Mass Spectrometry  

USGS Publications Warehouse

A method for the isolation and analysis of 21 parent pesticides and 20 pesticide degradates in natural-water samples is described. Water samples are filtered to remove suspended particulate matter and then are pumped through disposable solid-phase-extraction columns that contain octadecyl-bonded porous silica to extract the analytes. The columns are dried by using nitrogen gas, and adsorbed analytes are eluted with ethyl acetate. Extracted analytes are determined by capillary-column gas chromatography/mass spectrometry with selected-ion monitoring of three characteristic ions. The upper concentration limit is 2 micrograms per liter (?g/L) for most analytes. Single-operator method detection limits in reagent-water samples range from 0.00 1 to 0.057 ?g/L. Validation data also are presented for 14 parent pesticides and 20 degradates that were determined to have greater bias or variability, or shorter holding times than the other compounds. The estimated maximum holding time for analytes in pesticide-grade water before extraction was 4 days. The estimated maximum holding time for analytes after extraction on the dry solid-phase-extraction columns was 7 days. An optional on-site extraction procedure allows for samples to be collected and processed at remote sites where it is difficult to ship samples to the laboratory within the recommended pre-extraction holding time. The method complements existing U.S. Geological Survey Method O-1126-95 (NWQL Schedules 2001 and 2010) by using identical sample preparation and comparable instrument analytical conditions so that sample extracts can be analyzed by either method to expand the range of analytes determined from one water sample.

Sandstrom, Mark W.; Stroppel, Max E.; Foreman, William T.; Schroeder, Michael P.

2001-01-01

282

Pesticide Product Use and Risk of Non-Hodgkin Lymphoma in Women  

Microsoft Academic Search

A population-based, incidence case-control study was conducted among women in upstate New York to determine whether pesticide exposure is associated with an increase in risk of non-Hodgkin lymphoma (NHL) among women. The study involved 376 cases of NHL identified through the State Cancer Registry and 463 controls selected from the Medicare beneficiary files and state driver's license records. Information about

Ikuko Kato; Hiroko Watanabe-Meserve; Karen L. Koenig; Mark S. Baptiste; Patricia P. Lillquist; Glauco Frizzera; Jerome S. Burke; Miriam Moseson; Roy E. Shore

2004-01-01

283

Removal of pesticide mixtures in a stormwater wetland collecting runoff from a vineyard catchment.  

PubMed

Wetlands can collect contaminated runoff from agricultural catchments and retain dissolved and particle-laden pesticides. However, knowledge about the capacity and functioning of wetland systems with respect to the removal of pesticides is very limited. Here we show that stormwater wetlands can efficiently remove pesticides in runoff from vineyard catchments during the period of pesticide application, although flow and hydrochemical conditions of the wetland largely vary over time. During the entire agricultural season, the inflowing load of nine fungicides, six herbicides, one insecticide and four degradation products was 8.039g whereas the outflowing load was 2.181g. Removal rates of dissolved loads by the wetland ranged from 39% (simazine) to 100% (cymoxanil, gluphosinate, kresoxim methyl and terbuthylazine). Dimethomorph, diuron, glyphosate, metalaxyl and tetraconazole were more efficiently removed in spring than in summer. More than 88% of the input mass of suspended solids was retained, underscoring the capability of the wetland to trap pesticide-laden particles via sedimentation. Only the insecticide flufenoxuron was frequently detected in the wetland sediments. Our results demonstrate that stormwater wetlands can efficiently remove pesticide mixtures in agricultural runoff during critical periods of pesticide application, although fluctuations in the runoff regime and hydrochemical characteristics can affect the removal rates of individual pesticides. PMID:21353289

Maillard, Elodie; Payraudeau, Sylvain; Faivre, Etienne; Grégoire, Caroline; Gangloff, Sophie; Imfeld, Gwenaël

2011-05-01

284

Herbicides and herbicide degradation products in Upper Midwest agricultural streams during August base-flow conditions.  

PubMed

Herbicide concentrations in streams of the U.S. Midwest have been shown to decrease through the growing season due to a variety of chemical and physical factors. The occurrence of herbicide degradation products at the end of the growing season is not well known. This study was conducted to document the occurrence of commonly used herbicides and their degradation products in Illinois, Iowa, and Minnesota streams during base-flow conditions in August 1997. Atrazine, the most frequently detected herbicide (94%), was present at relatively low concentrations (median 0.17 microg L(-1)). Metolachlor was detected in 59% and cyanazine in 37% of the samples. Seven of nine compounds detected in more than 50% of the samples were degradation products. The total concentration of the degradation products (median of 4.4 microg L(-1)) was significantly greater than the total concentration of parent compounds (median of 0.26 microg L(-1)). Atrazine compounds were present less frequently and in significantly smaller concentrations in streams draining watersheds with soils developed on less permeable tills than in watersheds with soils developed on more permeable loess. The detection and concentration of triazine compounds was negatively correlated with antecedent rainfall (April-July). In contrast, acetanalide compounds were positively correlated with antecedant rainfall in late spring and early summer that may transport the acetanalide degradates into ground water and subsequently into nearby streams. The distribution of atrazine degradation products suggests regional differences in atrazine degradation processes. PMID:12809303

Kalkhoff, Stephen J; Lee, Kathy E; Porter, Stephen D; Terrio, Paul J; Thurman, E Michael

2003-01-01

285

Herbicides and herbicide degradation products in upper midwest agricultural streams during august base-flow conditions  

USGS Publications Warehouse

Herbicide concentrations in streams of the U.S. Midwest have been shown to decrease through the growing season due to a variety of chemical and physical factors. The occurrence of herbicide degradation products at the end of the growing season is not well known. This study was conducted to document the occurrence of commonly used herbicides and their degradation products in Illinois, Iowa, and Minnesota streams during base-flow conditions in August 1997. Atrazine, the most frequently detected herbicide (94%), was present at relatively low concentrations (median 0.17 ??g L-1). Metolachlor was detected in 59% and cyanazine in 37% of the samples. Seven of nine compounds detected in more than 50% of the samples were degradation products. The total concentration of the degradation products (median of 4.4 ??g L-1) was significantly greater than the total concentration of parent compounds (median of 0.26 ??g L-1). Atrazine compounds were present less frequently and in significantly smaller concentrations in streams draining watersheds with soils developed on less permeable tills than in watersheds with soils developed on more permeable loess. The detection and concentration of triazine compounds was negatively correlated with antecedent rainfall (April-July). In contrast, acetanalide compounds were positively correlated with antecedant rainfall in late spring and early summer that may transport the acetanalide degradates into ground water and subsequently into nearby streams. The distribution of atrazine degradation products suggests regional differences in atrazine degradation processes.

Kalkhoff, S. J.; Lee, K. E.; Porter, S. D.; Terrio, P. J.; Thurman, E. M.

2003-01-01

286

Relative Toxicity and Occurrence Patterns of Pesticide Mixtures in Streams Draining Agricultural Watersheds Dominated by Corn and Soybean Production  

Microsoft Academic Search

To evaluate the relative toxicity and the occurrence patterns of pesticide mixtures in streams draining agricultural watersheds, a 3-step approach was used. First, a landscape of interest was identified, defined, and isolated. Second, the relative toxicity of mixtures, on the basis of pesticide toxicity index scores, was compared with the relative toxicity of the highest individual pesticide, on the basis

Jason B Belden; Robert J Gilliom; Jeffrey D Martin; Michael J Lydy

2007-01-01

287

Identification and characterization of major degradation products of risperidone in bulk drug and pharmaceutical dosage forms.  

PubMed

Acid, base and oxygen stability of risperidone, a novel anti-psychotic drug, has been evaluated storing the sample in solution phase. One of the major degradation products has been identified and characterized by using techniques namely IR, MS and NMR after isolation by preparative LC. The other major degradation product has been identified with help of MS/MS data and by co-eluting in analytical LC with the available standard. The effect of acid and base resulted in the formation of hydroxy risperidone and the effect of oxygen lead to the formation of N-oxide of risperidone. The two major degradation products in the dosage forms were also characterized as 9-hydroxy risperidone and N-oxide of risperidone, after enrichment through preparative LC, by LC-MS/MS and HPLC. Structural elucidation of degradation product leading to the formation of N-oxide of risperidone is discussed in detail. PMID:15351071

Tomar, Rajesh Singh; Joseph, T J; Murthy, A S R; Yadav, D V; Subbaiah, G; Krishna Reddy, K V S R

2004-09-21

288

Summary of pesticide data from streams and wells in the Potomac River Basin, 1993-96  

USGS Publications Warehouse

Eighty-five water-soluble pesticides and pesticide degradation products were analyzed in 384 surface-water and ground-water samples collected from the Potomac River Basin during March 1993 through September 1996. Thirty-nine of these compounds were detected in surface-water samples and 16 were detected in ground-water samples. At least one pesticide was detected in 86 percent of the streams sampled and 45 percent of the wells sampled. Pesticides were detected more frequently and at higher concentrations in surface water than in ground water. The following four herbicides and one degradation product were the most frequently detected pesticides in both surface water and ground water: atrazine and metolachlor, which are used primarily on corn and soybean crops; prometon, which is used primarily in nonagricultural (urban and suburban) areas; simazine, which is used in both agricultural and nonagricultural areas, and desethylatrazine, which is one of the degradation products of atrazine. Insecticides were detected more frequently in surface water than in ground water. Diazinon, chlorpyrifos, and gamma-HCH (Undone) were found in more than 10 percent of surface-water samples, but in none of the ground-water samples.

Donnelly, Colleen A.; Ferrari, Matthew J.

1998-01-01

289

Toxicity and physical properties of atrazine and its degradation products: A literature survey  

SciTech Connect

The Tennessee Valley Authority`s Environmental Research Center has been developing a means of detoxifying atrazine waste waters using TiO{sub 2} photocatalysis. The toxicity and physical properties of atrazine and its degradation products will probably be required information in obtaining permits from the United States Environmental Protection Agency for the demonstration of any photocatalytic treatment of atrazine waste waters. The following report is a literature survey of the toxicological and physical properties of atrazine and its degradation products.

Pugh, K.C.

1994-10-01

290

Effects of the herbicide atrazine and its degradation products, alone and in combination, on phototrophic microorganisms  

Microsoft Academic Search

Toxic effects of the herbicide atrazine and four of its degradation products were determined for growth, photosynthesis, and acetylene-reducing ability of two species of green algae and three species of cyanobacteria. Atrazine was significantly more toxic than its degradation products towards the above test criteria, yielding EC50 values ranging from 0.1 to 0.5 ppm (µg\\/ml) for photosynthesis and 0.03 to

Glenn W. Stratton

1984-01-01

291

Identification and characterization of major degradation products of risperidone in bulk drug and pharmaceutical dosage forms  

Microsoft Academic Search

Acid, base and oxygen stability of risperidone, a novel anti-psychotic drug, has been evaluated storing the sample in solution phase. One of the major degradation products has been identified and characterized by using techniques namely IR, MS and NMR after isolation by preparative LC. The other major degradation product has been identified with help of MS\\/MS data and by co-eluting

Rajesh Singh Tomar; T. J. Joseph; A. S. R. Murthy; D. V. Yadav; G. Subbaiah; K. V. S. R. Krishna Reddy

2004-01-01

292

Spectrophotometric and liquid chromatographic determination of trimebutine maleate in the presence of its degradation products  

Microsoft Academic Search

Three methods are presented for the determination of trimebutine maleate (TM) in the presence of its degradation products. The first method was based on a high performance liquid chromatographic (HPLC) separation of TM from its degradation products using an ODS column at ambient temperature with a mobile phase consisting of acetonitrile—5 mM heptane sulfonic acid disodium salt (45:55, v\\/v, pH

Alaa El-Gindy; Samy Emara; Ghada M Hadad

2003-01-01

293

Chiral Pesticides: Identification, Description and Environmental Implications  

EPA Science Inventory

Anthropogenic chemicals, including pesticides, are a major source of contamination and pollution in the environment. Pesticides have many positive uses: increased food production, decreased damage to crops and structures, reduced disease vector populations, and more. Nevertheless...

294

Inhibitory effects on degradation of diesel oil in soil-microcosms by a commercial bioaugmentation product  

SciTech Connect

The effectiveness of bioaugmentation, i.e. inoculation using specific microbial degraders to enhance bioremediation of oil polluted soil, has been investigated by various authors: Jobson et al. (1974) and Lehtomaki & Niemela (1975) reported only marginal effects on degradation upon inoculation. Two commercial bioaugmentation products were recently tested by Venosa et al. (1992), who found no positive effects on oil degradation. Dott et al. (1989) reported that the oil degrading capacity (in liquid culture) of 9 commercial bioaugmentation products were inferior to that of activated sludge. In spite of these results, commercial products for bioaugmentation are readily available. The present study describes the effects of inoculating diesel oil polluted soil with a commercial bioaugmentation product. The investigation was carried out in laboratory scale using soil-microcosms. The results indicated that addition of small amounts of bioaugmentation product was without effects on diesel oil degradation. Addition of larger amounts of the product directly inhibited degradation during the entire experimental period of 61 days. 8 refs., 3 figs.

Moeller, J.; Gaarn, H.; Steckel, T.; Wedebye, E.B.; Westermann, P. [Univ. of Copenhagen (Denmark)

1995-06-01

295

Combining TiO 2photocatalysis and wetland reactors for the efficient treatment of pesticides  

Microsoft Academic Search

In the present work the photocatalytic and biological degradation of two commercial mixtures of pesticides (Folimat and Ronstar) and two fungicides (pyrimethanil and triadimenol) has been studied. The evolution of some components of these commercial products (dicofol, tetradifon and oxadiazon) and that of the two fungicides has been monitored by means of HPLC, GC–MS, TOC and toxicity (Lemna minor toxicity

J. Araña; C. Garriga i Cabo; C. Fernández Rodríguez; J. A. Herrera Melián; J. A. Ortega Méndez; J. M. Doña Rodríguez; J. Pérez Peña

2008-01-01

296

A Quantitative Approach for Ranking Human Health Risks from Pesticides in Irish Groundwater  

Microsoft Academic Search

This study aims to quantitatively assess the risk of pesticides (used in Irish agriculture) and their degradation products to groundwater and human health. This assessment uses a human health Monte-Carlo risk-based approach that includes the leached quantity combined with an exposure estimate and the No Observed Adverse Effect Level (NOAEL) as a toxicity ranking endpoint, resulting in a chemical intake

H. Labite; E. Cummins

2012-01-01

297

Microwave decomposition of a chlorinated pesticide (Lindane) supported on modified sepiolites  

Microsoft Academic Search

Inorganic porous materials based on modified sepiolites have been studied as supports for controlled degradation of Lindane, a chlorinated pesticide. In dry media conditions under microwave (MW) irradiation, sepiolite can dehydrohalogenate Lindane to pentachlorocyclohexene (PCCH). Trichlorobenzene (TCB) and PCCH are obtained with NaOH-modified sepiolite and, when nickel oxide is present in the solid, CO2 is also found as a product

Raquel Salvador; Blanca Casal; Malcolm Yates; M. Angeles Mart??n-Luengo; Eduardo Ruiz-Hitzky

2002-01-01

298

Automated sample preparation with extraction columns followed by liquid chromatography-ionspray mass spectrometry interferences, determination and degradation of polar organophosphorus pesticides in water samples  

Microsoft Academic Search

The determination of polar and\\/or thermally labile organophosphorus pesticides trichlorfon, dichlorvos, dimethoate, oxydemeton-methyl, mevinphos (cis and trans), demeton-S-methyl, fenamiphos, fenitrothion, fenthion and diazinon in water samples was investigated using solid-phase extraction followed by liquid chromatography-ionspray mass spectrometry (LC-ISP-MS). Pesticides were spiked at 0.2 ?g\\/l in ground water samples and 200 ml were preconcentrated by using an ASPEC XL system. To

C Molina; P Grasso; E Benfenati; D Barceló

1996-01-01

299

Poly(L-lactide)-degrading enzyme production by Actinomadura keratinilytica T16-1 in 3 L airlift bioreactor and its degradation ability for biological recycle.  

PubMed

The optimal physical factors affecting enzyme production in an airlift fermenter have not been studied so far. Therefore, the physical parameters such as aeration rate, pH, and temperature affecting PLA-degrading enzyme production by Actinomadura keratinilytica strain T16-1 in a 3 l airlift fermenter were investigated. The response surface methodology (RSM) was used to optimize PLA-degrading enzyme production by implementing the central composite design. The optimal conditions for higher production of PLA-degrading enzyme were aeration rate of 0.43 vvm, pH of 6.85, and temperature at 46° C. Under these conditions, the model predicted a PLA-degrading activity of 254 U/ml. Verification of the optimization showed that PLA-degrading enzyme production of 257 U/ml was observed after 3 days cultivation under the optimal conditions in a 3 l airlift fermenter. The production under the optimized condition in the airlift fermenter was higher than un-optimized condition by 1.7 folds and 12 folds with un-optimized medium or condition in shake flasks. This is the first report on the optimization of environmental conditions for improvement of PLA-degrading enzyme production in a 3 l airlift fermenter by using a statistical analysis method. Moreover, the crude PLA-degrading enzyme could be adsorbed to the substrate and degraded PLA powder to produce lactic acid as degradation products. Therefore, this incident indicates that PLA-degrading enzyme produced by Actinomadura keratinilytica NBRC 104111 strain T16-1 has a potential to degrade PLA to lactic acid as a monomer and can be used for the recycle of PLA polymer. PMID:22297224

Sukkhum, Sukhumaporn; Tokuyama, Shinji; Kitpreechavanich, Vichien

2012-01-01

300

The ARS Pesticide Properties Database  

NSDL National Science Digital Library

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

2005-12-06

301

Determination of degradation products of doxercalciferol by solid-phase extraction and reversed-phase HPLC.  

PubMed

In the current study, injectable formulations containing Doxercalciferol as the active pharmaceutical ingredient are analyzed by using gradient-elution high-performance liquid chromatography with ultraviolet detection. Various related impurities and degradants are quantified by using solid-phase extraction (SPE) for enhanced sensitivity. The assay of possible related impurities and Doxercalciferol analogues present at trace quantities is performed by using Trans-1-?-hydroxy vitamin D2 (Doxercalciferol related degradation product/Impurity B) as standard and 1-?-hydroxy vitamin D2 (Doxercalciferol related degradation product/Impurity C) as internal standards for the SPE study. The current method is shown to be stability-indicating and free from interferences from any of the formulation excipients and potential degradation products and impurities. The validated method is shown to be reproducible, accurate, sensitive and selective. PMID:23780943

Simonzadeh, Ninus; Ronsen, Bruce; Upadhyaya, Subhash; Wilkinson, Erik; Kanesvaran, Kiran; Patel, Vijay; Bendale, Pravin

2014-07-01

302

Pesticide bioconcentration modelling for fruit trees.  

PubMed

The model presented allows simulating the pesticide concentration evolution in fruit trees and estimating the pesticide bioconcentration factor in fruits. Pesticides are non-ionic organic compounds that are degraded in soils cropped with woody species, fruit trees and other perennials. The model allows estimating the pesticide uptake by plants through the water transpiration stream and also the time in which maximum pesticide concentration occur in the fruits. The equation proposed presents the relationships between bioconcentration factor (BCF) and the following variables: plant water transpiration volume (Q), pesticide transpiration stream concentration factor (TSCF), pesticide stem-water partition coefficient (K(Wood,W)), stem dry biomass (M) and pesticide dissipation rate in the soil-plant system (k(EGS)). The modeling started and was developed from a previous model "Fruit Tree Model" (FTM), reported by Trapp and collaborators in 2003, to which was added the hypothesis that the pesticide degradation in the soil follows a first order kinetic equation. The FTM model for pesticides (FTM-p) was applied to a hypothetic mango plant cropping (Mangifera indica) treated with paclobutrazol (growth regulator) added to the soil. The model fitness was evaluated through the sensitivity analysis of the pesticide BCF values in fruits with respect to the model entry data variability. PMID:17092536

Paraíba, Lourival Costa

2007-01-01

303

Atmospheric deposition of current-use and historic-use pesticides in snow at National Parks in the Western United States  

USGS Publications Warehouse

The United States (U.S.) National Park Service has initiated research on the atmospheric deposition and fate of semi-volatile organic compounds in its alpine, sub-Arctic, and Arctic ecosystems in the Western U.S. Results for the analysis of pesticides in seasonal snowpack samples collected in spring 2003 from seven national parks are presented herein. From a target analyte list of 47 pesticides and degradation products, the most frequently detected current-use pesticides were dacthal, chlorpyrifos, endosulfan, and ??- hexachlorocyclohexane, whereas the most frequently detected historic-use pesticides were dieldrin, ??-hexachlorocyclohexane, chlordane, and hexachlorobenzene. Correlation analysis with latitude, temperature, elevation, particulate matter, and two indicators of regional pesticide use reveal that regional current and historic agricultural practices are largely responsible for the distribution of pesticides in the national parks in this study. Pesticide deposition in the Alaskan parks is attributed to long-range transport because there are no significant regional pesticide sources. The percentage of total pesticide concentration due to regional transport (%RT) was calculated for the other parks. %RT was highest at parks with higher regional cropland intensity and for pesticides with lower vapor pressures and shorter half-lives in air. ?? 2006 American Chemical Society.

Hageman, K. J.; Simonich, S. L.; Campbell, D. H.; Wilson, G. R.; Landers, D. H.

2006-01-01

304

Activity of meadowfoam (Limnanthes alba) seed meal glucolimnanthin degradation products against soilborne pathogens.  

PubMed

Meadowfoam (Limnanthes alba L.) is a herbaceous winter-spring annual grown as a commercial oilseed crop. The meal remaining after oil extraction from the seed contains up to 4% of the glucosinolate glucolimnanthin. Degradation of glucolimnanthin yields toxic breakdown products, and therefore the meal may have potential in the management of soilborne pathogens. To maximize the pest-suppressive potential of meadowfoam seed meal, it would be beneficial to know the toxicity of individual glucolimnanthin degradation products against specific soilborne pathogens. Meloidogyne hapla second-stage juveniles (J2) and Pythium irregulare and Verticillium dahliae mycelial cultures were exposed to glucolimnanthin as well as its degradation products. Glucolimnanthin and its degradation product, 2-(3-methoxyphenyl)acetamide, were not toxic to any of the soilborne pathogens at concentrations up to 1.0 mg/mL. Two other degradation products, 2-(3-methoxymethyl)ethanethioamide and 3-methoxyphenylacetonitrile, were toxic to M. hapla and P. irregulare but not V. dahliae. The predominant enzyme degradation product, 3-methoxybenzyl isothiocyanate, was the most toxic compound against all of the soilborne pathogens, with M. hapla being the most sensitive with EC(50) values (0.0025 ± 0.0001 to 0.0027 ± 0.0001 mg/mL) 20-40 times lower than estimated EC(50) mortality values generated for P. irregulare and V. dahliae (0.05 and 0.1 mg/mL, respectively). The potential exists to manipulate meadowfoam seed meal to promote the production of specific degradation products. The conversion of glucolimnanthin into its corresponding isothiocyanate should optimize the biopesticidal properties of meadowfoam seed meal against M. hapla, P. irregulare, and V. dahliae. PMID:22142246

Zasada, Inga A; Weiland, Jerry E; Reed, Ralph L; Stevens, Jan F

2012-01-11

305

Identification by CI-mass spectrometry of an unexpected benzodiazepine degradation product  

NASA Astrophysics Data System (ADS)

The French Military Health Service (SSA) has developed an innovative drug product, as a treatment against neurotoxic organophosphate poisoning (NOP). It contains three drug substances: an anticholinergic, an anticonvulsant and a cholinesterase reactivator. Testing stability study, in normal conditions, over 18 months, for this speciality, has given unexpected results. Indeed, one of the drug substances, avizafone (pro-drug of diazepam), breaks down partially into a compound which migrates into the plastic container where this degradation product is demethylated after absorption. Mass spectrometry with negative chemical ionisation (negative CI-MS) was used, to monitor decomposition of the drug substance. This method first showed migration of the degradation product and has been used to monitor its evolution during the stability testing study. The demethylation seems to be due to an additive product present in the plastic. The degradation products remain trapped in the container holding the pharmaceutical formulation.

Buret, D.; Breton, D.; Clair, P.; Lafosse, M.

2006-01-01

306

Effect of organic, low-input and conventional production systems on pesticide and growth regulator residues in wheat, potato and cabbage  

Microsoft Academic Search

The Nafferton factorial systems comparison (NFSC) experiments facilitate the investigation of effects of, and interaction between, three production system components - a) rotational position, b) fertility and c) crop protection management - in organic, conventional and low-input crop management systems. This paper presents first results on pesticide and growth regulator residues observed over a period of two years. Residues were

L. Lueck; J. M. Cooper; P. N. Shotton; J. Hajslova; V. Schulzova

2007-01-01

307

The dioxin/POPs legacy of pesticide production in Hamburg: part 2--waste deposits and remediation of Georgswerder landfill.  

PubMed

?-HCH, ?-HCH, and ?-HCH (lindane) were listed as persistent organic pollutants in the Stockholm Convention. Therefore, they need to be globally addressed including the wastes remaining from historic use and production. While at most lindane production sites the unintentionally produced 85% HCH waste isomers have been deposited, at a former pesticide factory in Hamburg-Moorfleet HCH waste isomers have been recycled from 1953 to 1984 by thermal decomposition to chlorobenzenes and resulted in high polychlorinated dibenzo-p-dioxin/polychlorinated dibenzofuran (PCDD/PCDF)-contaminated residues. The management of the PCDD/PCDF-contaminated waste from the former pesticide factory in Hamburg has been assessed and quantified. Based on past accredited PCDD/PCDF measurements, the registered 3,700 tonnes of disposed thermal HCH decomposition residue contained 333 to 854 kg of PCDD/PCDF toxicity equivalent (I-TEQ) in 53-102 tonnes total sum of PCDD/PCDF. The wastes have been deposited together with other wastes in landfills in Hamburg and other parts of Germany. For the Georgswerder landfill (Hamburg), where approximately 50% of the PCDD/PCDF is disposed, current and previous situation and remediation activities are described. While PCDD/PCDF leaching from the landfill is controlled and incinerated, more water soluble organochlorines (vinyl chloride, cis-1,2-dichlorethene, chlorobenzenes) and benzene remain as a challenge for groundwater management. A comprehensive aftercare program has been established and will need to be operated by future generations including renewal of containment systems. Former lindane/HCH productions need-in addition to HCH deposits-to be assessed for possible recycling practice of HCH and related PCDD/PCDF-containing deposits. This could systematically be addressed within the Stockholm Convention implementation. PMID:22777611

Götz, Rainer; Sokollek, Volker; Weber, Roland

2013-04-01

308

Generation of toxic degradation products by sonication of Pluronic® dispersants: implications for nanotoxicity testing  

PubMed Central

Poloxamers (known by the trade name Pluronic®) are triblock copolymer surfactants that contain two polyethylene glycol blocks and one polypropylene glycol block of various sizes. Poloxamers are widely used as nanoparticle dispersants for nanotoxicity studies wherein nanoparticles are sonicated with a dispersant to prepare suspensions. It is known that poloxamers can be degraded during sonication and that reactive oxygen species contribute to the degradation process. However, the possibility that poloxamer degradation products are toxic to mammalian cells has not been well studied. We report here that aqueous solutions of poloxamer 188 (Pluronic® F-68) and poloxamer 407 (Pluronic® F-127) sonicated in the presence or absence of multi-walled carbon nanotubes (MWNTs) can became highly toxic to cultured cells. Moreover, toxicity correlated with the sonolytic degradation of the polymers. These findings suggest that caution should be used in interpreting the results of nanotoxicity studies where the potential sonolytic degradation of dispersants was not controlled.

Wang, Ruhung; Hughes, Tyler; Beck, Simon; Vakil, Samee; Li, Synyoung; Pantano, Paul; Draper, Rockford K.

2013-01-01

309

LC-MS/MS method for the characterization of the forced degradation products of Entecavir.  

PubMed

A rapid, specific, and reliable isocratic LC-MS/MS method has been developed and validated for the identification and characterization of the stressed degradation products of Entecavir (ETV). ETV, an antiviral drug, was subjected to hydrolysis (acidic, alkaline, and neutral), oxidation, photolysis and thermal stress, as per the international conference on harmonization specified conditions. The drug showed extensive degradation under oxidative and acid hydrolysis stress conditions. However, it was stable to thermal, acidic, neutral, and photolysis stress conditions. A total of five degradation products were observed and the chromatographic separation of the drug and its degradation products were achieved on a Waters Symmetry C18 (250 mm × 4.6 mm, id, 5 ?m) column using 20 mM ammonium acetate (pH 3)/acetonitrile (50:50, v/v) as a mobile phase. The degradation products were characterized by LC-MS/MS and its fragmentation pathways were proposed. The LC-MS method was validated with respect to specificity, linearity, accuracy, and precision. No previous reports were found in the literature regarding the degradation behavior of ETV. PMID:24323372

Ramesh, Thippani; Rao, Pothuraju Nageswara; Rao, Ramisetti Nageswara

2014-02-01

310

High performance liquid chromatographic determination of oxeladin citrate and oxybutynin hydrochloride and their degradation products.  

PubMed

Two high performance liquid chromatographic (HPLC) methods are presented for the determination of oxeladin citrate (OL) and oxybutynin hydrochloride (OB) and their degradation products. The first method was based on HPLC separation of OL from its degradation product using a Nucleosil C(18) column with a mobile phase consisting of acetonitrile -0.1% phosphoric acid (60:40 v/v). The second method was based on HPLC separation of OB from its degradation product using a VP-ODS C(18) column with a mobile phase consisting of acetonitrile/0.01 M potassium dihydrogen phosphate/diethylamine (60:40:0.2). Quantitation was achieved with UV detection at 220 nm based on peak area. The two HPLC methods were applied for the determination of OL or OB, their degradation products, methylparaben and propylparaben in pharmaceutical preparations. The proposed methods were used to investigate the kinetics of acidic and alkaline degradation processes of OL and OB at different temperatures and the apparent pseudofirst-order rate constant, half-life and activation energy were calculated. The pH-rate profiles of degradation of OL and OB in Britton-Robinson buffer solutions within the pH range 2-12 were studied. PMID:16023117

El-Gindy, Alaa

2005-08-01

311

LC-MS/MS characterization of forced degradation products of zofenopril.  

PubMed

A rapid, specific and reliable isocratic LC-MS/MS method has been developed and validated for the identification and characterization of stressed degradation products of Zofenopril. Zofenopril, an anti-hypertensive drug, was subjected to hydrolysis (acidic, alkaline and neutral), oxidation, photolysis and thermal stress, as per ICH-specified conditions. The drug showed extensive degradation under oxidative and base hydrolysis stress conditions. However, it was stable to thermal, acid, neutral and photolysis stress conditions. A total of 6 degradation products were observed and the chromatographic separation of the drug and its degradation products were achieved on Phenomenex (Luna) C18 (250mm×4.6mm, i.d., 5?m) column using 20mM ammonium acetate: acetonitrile (50:50, v/v) as a mobile phase. The degradation products were characterized by LC-MS/MS and its fragmentation pathways were proposed. The LC-MS method was validated with respect to specificity, linearity, accuracy and precision. No previous reports were found in the literature regarding the degradation behavior of zofenopril. PMID:24211724

Ramesh, Thippani; Nageswara Rao, Pothuraju; Nageswara Rao, Ramisetti

2014-01-01

312

Can degradation products be used as documentation for natural attenuation of phenoxy acids in groundwater?  

PubMed

In situ indicators of degradation are important tools in the demonstration of natural attenuation. A literature survey on the production history of phenoxy acids and degradation pathways has shown that metabolites of phenoxy acid herbicides also are impurities in the herbicide products, making the bare presence of these compounds useless as in situ indicators. These impurities can make up more than 30% of the herbicides. Degradation of phenoxy acids was demonstrated in microcosm experiments using groundwater and sediment contaminated with MCPP, dichlorprop, and related compounds such as other phenoxypropionic acids and chlorophenols. Field observations at two phenoxy acid-contaminated sites showed the occurrence of several impurities including metabolites in the groundwater. Neither the microcosm experiments nor the field observations verified that metabolites were actually produced or accumulated in situ. However, it was demonstrated that the impurity/parent herbicide ratios can be useful in situ indicators of degradation. PMID:14750720

Reitzel, Lotte A; Tuxen, Nina; Ledin, Anna; Bjerg, Poul L

2004-01-15

313

Products from the Incomplete Metabolism of Pyrene by Polycyclic Aromatic Hydrocarbon-Degrading Bacteria  

Microsoft Academic Search

Pyrene is a regulated pollutant at sites contaminated with polycyclic aromatic hydrocarbons (PAH). It is mineralized by some bacteria but is also transformed to nonmineral products by a variety of other PAH- degrading bacteria. We examined the formation of such products by four bacterial strains and identified and further characterized the most apparently significant of these metabolites. Pseudomonas stutzeri strain

CHIKOMA KAZUNGA; MICHAEL D. AITKEN

2000-01-01

314

Products from the incomplete metabolism of pyrene by polycyclic aromatic hydrocarbon-degrading bacteria  

Microsoft Academic Search

Pyrene is a regulated pollutant at sites contaminated with polycyclic aromatic hydrocarbons (PAH). It is mineralized by some bacteria but is also transformed to nonmineral products by a variety of other PAH-degrading bacteria. The authors examined the formation of such products by four bacterial strains and identified and further characterized the most apparently significant of these metabolites. Pseudomonas stutzeri strain

C. Kazunga; M. D. Aitken

2000-01-01

315

The influence of core degradation phenomena on in-vessel fission product behavior during severe accidents  

Microsoft Academic Search

In-vessel core degradation phenomena influence where fission products will be located and in what chemical forms they will exist and with what materials they will be associated at the time the lower vessel fails in an unmitigated accident sequence. Fission products released from the reactor vessel during the in-vessel phase of core melt progression in a severe reactor accident can

R. R. Hobbins; D. J. Osetek; D. A. Petti; D. L. Hagrman

1988-01-01

316

Minor Strecker degradation products of phenylalanine and phenylglycine  

Microsoft Academic Search

Phenylalanine (Phe) was oxidized with either potassium peroxodisulfate or glyoxal. Volatile reaction products were isolated and analyzed by GC\\/FID and GC\\/MS. Nonvolatile products were derivatized with diazomethane and analyzed by the same methods. Under the experimental reaction conditions (equimolar ratio of reactants, 100vv°C, 1 h), the decomposed amount of amino acid was 28% (glyoxal) and to 74% (peroxodisulfate), respectively. Sixteen

J. Adamiec; J. Rössner; J. Velíšek; Karel Cejpek; Jan Šavel

2001-01-01

317

Degradation of procyanidins by Aspergillus fumigatus: Identification of a novel aromatic ring cleavage product  

Microsoft Academic Search

Aspergillus fumigatus was able to grow on apple-purified procyanidins (PCs). PCs concentration decreased 30% over the first 60h of liquid fermentation. The mean degree of polymerization (DPn) of apple-purified PCs increased from 8 to 15 during the fermentation. A fungal enzyme extract from the liquid fermentation was used to study procyanidin B2 [(?)-epicatechin-(4?-8)-(?)-epicatechin] degradation. The major degradation product (PB2-X) had

Monica Contreras-Domínguez; Sylvain Guyot; Nathalie Marnet; Jean Le Petit; Isabelle Perraud-Gaime; Sevastianos Roussos; Christopher Augur

2006-01-01

318

Hydrolysis patterns and the production of peptide intermediates during protein degradation in marine systems  

Microsoft Academic Search

Matrix-assisted laser desorption\\/ionization time of flight mass spectrometry (MALDI-TOF-MS) was used to evaluate the degradation of the protein bovine serum albumin (BSA) added to seawater. The production of peptides during degradation, the size of the peptides produced and the within-protein locations of protease attack were all monitored in an effort to evaluate whether specific types of proteases or specific peptide

Brook L. Nunn; Angela Norbeck; Richard G. Keil

2003-01-01

319

75 FR 32766 - Notice of Receipt of Requests to Voluntarily Cancel Certain Pesticide Registrations  

Federal Register 2010, 2011, 2012, 2013

...of Receipt of Requests to Voluntarily Cancel Certain Pesticide Registrations AGENCY...or Mosquitoes, LLC., to voluntarily cancel the pesticide registration for the product...Mosquitoes, LLC., the registrant, to cancel the pesticide product listed in...

2010-06-09

320

Forced degradation studies of corticosteroids with an alumina-steroid-ethanol model for predicting chemical stability and degradation products of pressurized metered-dose inhaler formulations.  

PubMed

An alumina (Al(2)O(3))-steroid-ethanol model is used for forced degradation testing of corticosteroids to predict chemical stability and degradation products in pressurized metered-dose inhaler (pMDI) solution formulations. The model involves an ethanolic solution of a test steroid with Al(2)O(3), stressed at elevated temperatures to mimic the chemical interaction of drug, excipient, and packaging (an aluminum aerosol canister). The reactivity order of eight synthetic corticosteroids toward Al(2)O(3)-induced reactions is ranked with the stress model. The corticosteroids containing a C21-OH group possess the highest reactivity, suggesting that aluminum canisters with an inert interior coating are needed to stabilize their solution pMDIs. The Al(2)O(3)-induced degradation products and degradation pathways of a steroid containing C21-OH and triamcinolone acetonide are presented, and the role of Al(2)O(3) in the degradation pathways is briefly discussed. A potential degradation profile of beclomethasone dipropionate (BDP) established with an Al(2)O(3)-BDP-ethanol stress model is the same as the actual degradation profile of the BDP pMDI product, indicating that the model indeed predicts the degradation products. PMID:22410760

Wu, Zheng-Zhi; Thatcher, Matthew L; Lundberg, James K; Ogawa, Mark K; Jacoby, Cliffton B; Battiste, John L; Ledoux, Katherine A

2012-06-01

321

Elastin Production and Degradation in Cutis Laxa Acquisita  

Microsoft Academic Search

A case of cutis laxa acquisita was studied with the aim of defining the molecular defects involved and comparing them with those of an inherited form of cutis laxa. In the acquisita form of cutis laxa ultrastructural and biochemical observations confirmed a dramatic reduction of dermal elastin, whereas collagen content was normal. Elastin mRNA expression as well as tropoelastin production

Claudio Fornieri; Daniela Quaglino; Giuseppe Lungarella; Eleonora Cavarra; Roberta Tiozzo; Maria Gabriella Giro; Mario Canciani; Jeffrey M. Davidson; Ivonne Pasquali Ronchetti

1994-01-01

322

ATMOSPHERIC REACTION PRODUCTS FROM HAZARDOUS AIR POLLUTANT DEGRADATION  

EPA Science Inventory

This research project was undertaken to investigate the products of selected hazardous air pollutants (HAPs) as they react in the atmosphere. Many hazardous or potentially hazardous organic compounds are emitted into the atmosphere and are subject to chemical change by photolysis...

323

Removal of Hydrocarbon Degradation Products from Organic Solutions.  

National Technical Information Service (NTIS)

The liquid-liquid extraction process is for the separation of uranium values from an aqueous acidic solution containing the values together with nitrate values and zirconium and niobium fission product values. The process relates to the removal from the o...

J. M. Schmitt

1964-01-01

324

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

PubMed

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

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

2013-08-01

325

Occurrence and distribution of pesticides in surface waters of the Hood River basin, Oregon, 1999-2009  

USGS Publications Warehouse

The U.S. Geological Survey analyzed pesticide and trace-element concentration data from the Hood River basin collected by the Oregon Department of Environmental Quality (ODEQ) from 1999 through 2009 to determine the distribution and concentrations of pesticides in the basin's surface waters. Instream concentrations were compared to (1) national and State water-quality standards established to protect aquatic organisms and (2) concentrations that cause sublethal or lethal effects in order to assess their potential to adversely affect the health of salmonids and their prey organisms. Three salmonid species native to the basin are listed as "threatened" under the U.S. Endangered Species Act: bull trout, steelhead, and Chinook salmon. A subset of 16 sites was sampled every year by the ODEQ for pesticides, with sample collection targeted to months of peak pesticide use in orchards (March-June and September). Ten pesticides and four pesticide degradation products were analyzed from 1999 through 2008; 100 were analyzed in 2009. Nineteen pesticides were detected: 11 insecticides, 6 herbicides, and 2 fungicides. Two of four insecticide degradation products were detected. All five detected organophosphate insecticides and the one detected organochlorine insecticide were present at concentrations exceeding water-quality standards, sublethal effects thresholds, or acute toxicity values in one or more samples. The frequency of organophosphate detection in the basin decreased during the period of record; however, changes in sampling schedule and laboratory reporting limits hindered clear analysis of detection frequency trends. Detected herbicide and fungicide concentrations were less than water-quality standards, sublethal effects thresholds, or acute toxicity values. Simazine, the most frequently detected pesticide, was the only herbicide detected at concentrations within an order of magnitude (factor of 10) of concentrations that impact salmonid olfaction. Some detected pesticides are of concern, not for their toxicity alone, but for their ability to potentiate the harmful impacts of other pesticides, particularly organophosphates, on salmonids or their prey. Many samples contained mixtures of pesticides, but the effects to salmonids of relevant mixtures at environmentally realistic concentrations for the basin are unknown. Trace-element concentration data, although limited, indicate that eight trace elements are also of concern for their potential to harm salmonid health. The dataset is limited with regard to the spatial and seasonal distribution of pesticides and trace elements in all salmonid-bearing streams, the presence of particle-bound pesticides, and the presence of several unmonitored pesticides known to be used in the basin.

Temple, Whitney B.; Johnson, Henry M.

2011-01-01

326

Rapid multiplug filtration cleanup with multiple-walled carbon nanotubes and gas chromatography-triple-quadruple mass spectrometry detection for 186 pesticide residues in tomato and tomato products.  

PubMed

This study reports the development and validation of a novel rapid cleanup method based on multiple-walled carbon nanotubes in a packed column filtration procedure for analysis of pesticide residues followed by gas chromatography-triple-quadruple tandem mass spectrometry detection. The cleanup method was carried out by applying the streamlined procedure on a multiplug filtration cleanup column with syringes. The sorbent used for removing the interferences in the matrices is multiple-walled carbon nanotubes mixed with anhydrous magnesium sulfate. The proposed cleanup method is convenient and time-saving as it does not require any solvent evaporation, vortex, or centrifugation procedures. It was validated on 186 pesticides and 3 tomato product matrices spiked at two concentration levels of 10 and 100 ?g kg(-1). Satisfactory recoveries and relative standard deviations are shown for most pesticides using the multiplug filtration cleanup method in tomato product samples. The developed method was successfully applied to the determination of pesticide residues in market samples. PMID:24512455

Zhao, Pengyue; Huang, Baoyong; Li, Yanjie; Han, Yongtao; Zou, Nan; Gu, Kejia; Li, Xuesheng; Pan, Canping

2014-04-30

327

40 CFR 158.2220 - Product performance.  

Code of Federal Regulations, 2013 CFR

... DATA REQUIREMENTS FOR PESTICIDES Antimicrobial Pesticide Data Requirements § 158...Product performance requirement for all antimicrobial pesticides. Each applicant...product performance data requirements for antimicrobial pesticide products. (b)...

2013-07-01

328

The sources, fate, and toxicity of chemical warfare agent degradation products.  

PubMed Central

We include in this review an assessment of the formation, environmental fate, and mammalian and ecotoxicity of CW agent degradation products relevant to environmental and occupational health. These parent CW agents include several vesicants: sulfur mustards [undistilled sulfur mustard (H), sulfur mustard (HD), and an HD/agent T mixture (HT)]; nitrogen mustards [ethylbis(2-chloroethyl)amine (HN1), methylbis(2-chloroethyl)amine (HN2), tris(2-chloroethyl)amine (HN3)], and Lewisite; four nerve agents (O-ethyl S-[2-(diisopropylamino)ethyl] methylphosphonothioate (VX), tabun (GA), sarin (GB), and soman (GD)); and the blood agent cyanogen chloride. The degradation processes considered here include hydrolysis, microbial degradation, oxidation, and photolysis. We also briefly address decontamination but not combustion processes. Because CW agents are generally not considered very persistent, certain degradation products of significant persistence, even those that are not particularly toxic, may indicate previous CW agent presence or that degradation has occurred. Of those products for which there are data on both environmental fate and toxicity, only a few are both environmentally persistent and highly toxic. Major degradation products estimated to be of significant persistence (weeks to years) include thiodiglycol for HD; Lewisite oxide for Lewisite; and ethyl methyl phosphonic acid, methyl phosphonic acid, and possibly S-(2-diisopropylaminoethyl) methylphosphonothioic acid (EA 2192) for VX. Methyl phosphonic acid is also the ultimate hydrolysis product of both GB and GD. The GB product, isopropyl methylphosphonic acid, and a closely related contaminant of GB, diisopropyl methylphosphonate, are also persistent. Of all of these compounds, only Lewisite oxide and EA 2192 possess high mammalian toxicity. Unlike other CW agents, sulfur mustard agents (e.g., HD) are somewhat persistent; therefore, sites or conditions involving potential HD contamination should include an evaluation of both the agent and thiodiglycol. Images Figure 1 Figure 3 Figure 5

Munro, N B; Talmage, S S; Griffin, G D; Waters, L C; Watson, A P; King, J F; Hauschild, V

1999-01-01

329

Extraction of acidic degradation products of organophosphorus chemical warfare agents  

Microsoft Academic Search

The analysis of alkyl alkylphosphonic acids (AAPAs) and alkylphosphonic acids (APAs), the hydrolyzed products of nerve agents, constitutes an important aspect for verifying the compliance to the Chemical weapons convention (CWC). This work devotes on the development of solid-phase extraction method using polymeric mixed-mode strong anion-exchange (Oasis MAX) cartridges for extraction of AAPAs and APAs from water. The extracted analytes

Pankaj K. Kanaujia; Deepak Pardasani; A. K. Gupta; Rajesh Kumar; R. K. Srivastava; D. K. Dubey

2007-01-01

330

Degradation of trichloronitromethane by iron water main corrosion products  

Microsoft Academic Search

Halogenated disinfection byproducts (DBPs) may undergo reduction reactions at the corroded pipe wall in drinking water distribution systems consisting of cast or ductile iron pipe. Iron pipe corrosion products were obtained from several locations within two drinking water distribution systems. Crystalline-phase composition of freeze-dried corrosion solids was analyzed using X-ray diffraction, and ferrous and ferric iron contents were determined via

Jeong-Yub Lee; Carrie R. Pearson; Raymond M. Hozalski; William A. Arnold

2008-01-01

331

Toxicity of thermal degradation products of spacecraft materials  

NASA Technical Reports Server (NTRS)

Three polymeric materials were evaluated for relative toxicity of their pyrolysis products to rats by inhalation: Y-7683 (LS 200), Y-7684 (Vonar 3 on Fiberglass), and Y-7685 (Vonar 3 on N W Polyester). Criteria employed for assessing relative toxicity were (1) lethality from in-chamber pyrolysis, (2) lethality from an outside-of-chamber pyrolysis MSTL Procedure, and (3) disruption of trained rats' shock-avoidance performance during sub-lethal exposures to in-chamber pyrolysis of the materials.

Lawrence, W. H.; Turner, J. E.; Sanford, C.; Foster, S.; Baldwin, E.; Oconnor, J.

1982-01-01

332

78 FR 3418 - Pesticides; Draft Guidance for Pesticide Registrants on Web-Distributed Labeling for Pesticide...  

Federal Register 2010, 2011, 2012, 2013

...Notice) titled ``Web-Distributed Labeling for Pesticide Products...through the Internet. Web-distributed labeling would allow users...misuse of pesticides. Web-distributed labeling would also allow...the current paper-based system. DATES: Comments must...

2013-01-16

333

Isolation and Characterization of Cetirizine Degradation Product: Mechanism of Cetirizine Oxidation  

Microsoft Academic Search

Purpose  The goal of the study was to isolate and analyze a cetirizine degradation product, formed within a PEG-containing formulation\\u000a and to elucidate the mechanism of oxidation of cetirizine.\\u000a \\u000a \\u000a \\u000a \\u000a Methods  Cetirizine, formulated in PEG-containing matrix, was subjected to forced degradation conditions in the pH range from 3 to\\u000a 10, and the product was analyzed by HPLC and LC-MS\\/MS. Additionally, pure cetirizine was

Tatyana Dyakonov; April Muir; Hassen Nasri; Dana Toops; Aqeel Fatmi

2010-01-01

334

Modelling the degradation of endogenous residue and 'unbiodegradable' influent organic suspended solids to predict sludge production.  

PubMed

Activated sludge models have assumed that a portion of organic solids in municipal wastewater influent is unbiodegradable. Also, it is assumed that solids from biomass decay cannot be degraded further. The paper evaluates these assumptions based on data from systems operating at higher than typical sludge retention times (SRTs), including membrane bioreactor systems with total solids retention (no intentional sludge wastage). Data from over 30 references and with SRTs of up to 400 d were analysed. A modified model that considers the possible degradation of the two components is proposed. First order degradation rates of approximately 0.007 d(-1) for both components appear to improve sludge production estimates. Factors possibly influencing these degradation rates such as wastewater characteristics and bioavailability are discussed. PMID:23306256

Spérandio, Mathieu; Labelle, Marc-André; Ramdani, Abdellah; Gadbois, Alain; Paul, Etienne; Comeau, Yves; Dold, Peter L

2013-01-01

335

Pure ZnO and composite ZnO/TiO2 catalyst plates: A comparative study for the degradation of azo dye, pesticide and antibiotic in aqueous solutions.  

PubMed

Photocatalytic degradations of azo dye (RR 180), pesticide (2,4-D) and antibiotic (enrofloxacin) in aqueous solutions were performed and compared by using pure ZnO and ZnO/TiO2 composite (at 1:1 ZnO to TiO2 mole ratio) catalysts in a self-supporting plate form. The plates were produced by tape casting of the constituent powder slurries and sintering at 600°C. Photocatalytic degradations of these pollutants were carried out under UVA and UVC irradiations for 120min. Maximum degradation was obtained for 2,4-D solution using pure ZnO plates under UVC. Due to the photolysis effect, UVC wavelength yielded higher efficiency values for all the chemicals than UVA. The discrepancy in the photocatalytic performances of the pure ZnO and the ZnO/TiO2 composite plates were not found to be significant. The plates were found to be effective for the consecutive degradation tests which indicated their potentiality in extended applications. PMID:24998047

Topkaya, Eylem; Konyar, Mehmet; Yatmaz, H Cengiz; Oztürk, Koray

2014-09-15

336

Detection of explosives and their degradation products in soil environments  

Microsoft Academic Search

Polynitro organic explosives [hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) and 2,4,6-trinitrotoluene (TNT)] are typical labile environmental pollutants that can biotransform with soil indigenous microorganisms, photodegrade by sunlight and migrate through subsurface soil to cause groundwater contamination. To be able to determine the type and concentration of explosives and their (bio)transformation products in different soil environments, a comprehensive analytical methodology of sample preparation,

A Halasz; C Groom; E Zhou; L Paquet; C Beaulieu; S Deschamps; A Corriveau; S Thiboutot; G Ampleman; C Dubois; Jalal Hawari

2002-01-01

337

Sampling and Substrate Application Methods for Pesticide Mineralization Experiments in Undisturbed Soil Samples  

Microsoft Academic Search

Different strategies for pesticide mineralization experiments have been proposed in the literature. The structural state of the soil as well as the method for applying pesticide to the soil can be anticipated to affect the mineralization of the pesticide. Also the soil water content during mineralization is important for the degradation of pesticide. The present study focused on different sampling

Inge S. Fomsgaard; Gitte Felding; Per Schjønning

1998-01-01

338

Evaluation of the pesticide contamination of groundwater sampled over two years from a vulnerable zone in Portugal.  

PubMed

A monitoring program of pesticides was implemented in the "ZV1" vulnerable zone (Directive 91/676/EEC) in Portugal, in order to assess the impact of intensive horticulture practices on groundwater contamination. The monitoring network comprised 23 sampling points sampled every 3 months during a 2-year period. Forty-two pesticides belonging to varied chemical families, including current pesticides, persistent organic pollutants (POPs), and degradation products, were analyzed by solid-phase microextraction (SPME) and gas chromatography with electron-capture detection-thermoionic specific detection (GC-ECD-TSD) or mass spectrometry (GC-MS). Statistical treatment was performed by descriptive analysis followed by chemometric multivariate analysis. The latter included cluster analysis, linear discriminant analysis, and factor analysis. Twenty-two pesticides were quantitated, 20 pesticides were not detected, and metalaxyl, benalaxyl, quinalphos, pirimicarb, and prometryn were only qualitatively detected. The most frequently detected pesticides (% of samples analyzed) were lindane (53%), pendimethalin (49%), endosulfan sulfate (44%), and endosulfan (38%) while those that most frequently exceeded the 0.1 mug L-1 European Union (EU) limit were pendimethalin (13%), endosulfan (12%), endosulfan sulfate (11%), and atrazine (9%). 45% of the samples exceeded the EU limit for individual pesticides while 27% exceeded the limit set to the sum of pesticides (0.5 mug L-1). Principal component analysis revealed five principal components that were attributed to environmental/agrochemical managing factors. The broad range of pesticides investigated combined with the intensive character of the local agriculture contributed to the diversity of pesticides that were detected. However, the frequency of pesticides above the EU regulatory limit is comparable to that found in the literature concerning different Portuguese and European regions. PMID:17608425

Gonçalves, Carlos M; Silva, Joaquim C G Esteves da; Alpendurada, Maria F

2007-07-25

339

Modification of water-soluble coal-derived products by dibenzothiophene-degrading microorganisms  

SciTech Connect

To study mechanisms by which microorganisms oxidize thiophenic sulfur in coal, we tested bacterial cultures for the ability to degrade dibenzothiophene (DBT), DBT-5-oxide, and DBT-sulfone and to modify water-soluble coal products derived from Illinois no. 6 and Ugljevik coals. In yeast extract medium, the majority of selected isolates degraded DBT and accumulated DBT-5-oxide in culture fluids; all but one of the cultures degraded DBT-5-oxide, and none of them degraded DBT-sulfone. Elemental analysis data indicated that the microbial cultures were able to decrease the amount of sulfur in soluble coal products derived from Illinois no. 6 and Ugljevik coals. However, these data suggested that microbially mediated sulfur removal from soluble Ugljevik coal occurred by nonspecific mechanisms. That is, extensive degradation of the carbon structure was concurrent with the loss of sulfur. This conclusion was supported by X-ray photoelectron spectroscopic data which indicated that the reduced sulfur forms in the soluble Ugljevik coal product was not oxidized by microbial treatment.

Stoner, D.L.; Wey, J.E.; Barrett, K.B.; Jolley, J.G.; Wright, R.B.; Dugan, P.R. (Idaho National Engineering Laboratory, Idaho Falls (USA))

1990-09-01

340

Modification of Water-Soluble Coal-Derived Products by Dibenzothiophene-Degrading Microorganisms  

PubMed Central

To study mechanisms by which microorganisms oxidize thiophenic sulfur in coal, we tested bacterial cultures for the ability to degrade dibenzothiophene (DBT), DBT-5-oxide, and DBT-sulfone and to modify water-soluble coal products derived from Illinois no. 6 and Ugljevik coals. In yeast extract medium, the majority of selected isolates degraded DBT and accumulated DBT-5-oxide in culture fluids; all but one of the cultures degraded DBT-5-oxide, and none of them degraded DBT-sulfone. Elemental analysis data indicated that the microbial cultures were able to decrease the amount of sulfur in soluble coal products derived from Illinois no. 6 and Ugljevik coals. However, these data suggested that microbially mediated sulfur removal from soluble Ugljevik coal occurred by nonspecific mechanisms. That is, extensive degradation of the carbon structure was concurrent with the loss of sulfur. This conclusion was supported by X-ray photoelectron spectroscopic data which indicated that the reduced sulfur forms in the soluble Ugljevik coal product was not oxidized by microbial treatment.

Stoner, D. L.; Wey, J. E.; Barrett, K. B.; Jolley, J. G.; Wright, R. B.; Dugan, P. R.

1990-01-01

341

Pesticides' influence on wine fermentation.  

PubMed

Wine quality strongly depends on the grape quality. To obtain high-quality wines, it is necessary to process healthy grapes at the correct ripeness stage and for this reason the farmer has to be especially careful in the prevention of parasite attacks on the grapevine. The most common fungal diseases affecting grape quality are downy and powdery mildew (Plasmopara viticola and Uncinula necator), and gray mold (Botrytis cinerea). On the other hand, the most dangerous insects are the grape moth (Lobesia botrana), vine mealybug (Planococcus ficus), and the citrus mealybug (Planococcus citri). Farmers fight grape diseases and insects applying pesticides that can be found at harvest time on grapes. The persistence of pesticides depends on the chemical characteristic of the active ingredients as well as on photodegradation, thermodegradation, codistillation, and enzymatic degradation. The pesticide residues on grapes can be transferred to the must and this can influence the selection and development of yeast strains. Moreover, yeasts can also influence the levels of the pesticides in the wine by reducing or adsorbing them on lees. During the fermentative process, yeasts can cause the disappearance of pesticide residues by degradation or absorption at the end of the fermentation when yeasts are deposited as lees. In this chapter, we reviewed the effect of commonly used herbicides, insecticides, and fungicides on yeasts. We also studied the effect of alcoholic and malolactic fermentation on pesticide residues. PMID:20610173

Caboni, Pierluigi; Cabras, Paolo

2010-01-01

342

Identification, characterization and cytotoxicity in vitro assay of nitazoxanide major degradation product.  

PubMed

Stress studies of the broad-spectrum antiparasitic nitazoxanide were conducted in order to isolate and elucidate the major degradation product involved in thermal, acid, alkaline, oxidative and photolytic decomposition of the drug in solution and solid state. The major degradation product was identified and characterized using techniques namely LC-DAD, (1)H NMR, (13)C NMR, IR, and MS/MS. The stability of nitazoxanide raw material and nitazoxanide in tablets and in suspension powder was studied under different conditions and the results suggest the formation of the same deacetylated degradation product occur in all cases. This product was also studied in order to determine the preliminary cytotoxicity in vitro with mononuclear cells. Compared with nitazoxanide, the degradation product showed a higher cytotoxicity at a concentration of 40 ?g mL(-1) after 48 h of incubation, under tested conditions. Therefore, stress studies showed that special care must be taken during the preparation, manufacture, and storage of this pharmaceutical drug. PMID:22483900

Malesuik, Marcelo Donadel; Gonçalves, Heloísa Mazotti Lopes; Garcia, Cássia Virginia; Trein, Márcia Rodrigues; Nardi, Nance Beyer; Schapoval, Elfrides Eva Scherman; Steppe, Martin

2012-05-15

343

Part played by degradation products in the corrosion of gas sweetening plants using DEA and MDEA  

SciTech Connect

The experiments reported in this work are results of the most representative tests of the work done in Elf Aquitaine's Laboratories. The general conclusion is that degradation products of amines, DEA and MDEA, have no practical effect upon the corrosion rate of carbon steel. The reasons for this are different according as the products are basic or acid. Basic products, which are only slightly basic, cannot have a part in acid corrosion process. Some tests have even been performed to use this type of product as corrosion inhibitors. As for acid products, they play no part either, because of their low content in amine solutions. 27 references.

Blanc, C.; Grall, M.; Demarais, G.

1982-01-01

344

Probabilistic Modeling for Risk Assessment of California Ground Water Contamination by Pesticides  

NASA Astrophysics Data System (ADS)

The California Department of Pesticide Regulation (DPR) is responsible for the registration of pesticides in California. DPR's Environmental Monitoring Branch evaluates the potential for pesticide active ingredients to move to ground water under legal agricultural use conditions. Previous evaluations were primarily based on threshold values for specific persistence and mobility properties of pesticides as prescribed in the California Pesticide Contamination Prevention Act of 1985. Two limitations identified with that process were the univariate nature where interactions of the properties were not accounted for, and the inability to accommodate multiple values of a physical-chemical property. We addressed these limitations by developing a probabilistic modeling method based on prediction of potential well water concentrations. A mechanistic pesticide transport model, LEACHM, is used to simulate sorption, degradation and transport of a candidate pesticide through the root zone. A second empirical model component then simulates pesticide degradation and transport through the vadose zone to a receiving ground water aquifer. Finally, degradation during transport in the aquifer to the well screen is included in calculating final potential well concentrations. Using Monte Carlo techniques, numerous LEACHM simulations are conducted using random samples of the organic carbon normalized soil adsorption coefficients (Koc) and soil dissipation half-life values derived from terrestrial field dissipation (TFD) studies. Koc and TFD values are obtained from gamma distributions fitted to pooled data from agricultural-use pesticides detected in California ground water: atrazine, simazine, diuron, bromacil, hexazinone, and norflurazon. The distribution of predicted well water concentrations for these pesticides is in good agreement with concentrations measured in domestic wells in coarse, leaching vulnerable soils of Fresno and Tulure Counties. The leaching potential of a new pesticide is evaluated by substituting it's sorption and persistence data into the model. Because such Koc and TFD data are often sparse, model inputs are typically derived from sampling of a fitted simple triangular distribution. A new product is considered to be a potential ground water contaminant if the 95th percentile of predicted well water concentrations is greater than 0.05 mg/L.

Clayton, M.; Troiano, J.; Spurlock, F.

2007-12-01

345

Degradation of trichloronitromethane by iron water main corrosion products.  

PubMed

Halogenated disinfection byproducts (DBPs) may undergo reduction reactions at the corroded pipe wall in drinking water distribution systems consisting of cast or ductile iron pipe. Iron pipe corrosion products were obtained from several locations within two drinking water distribution systems. Crystalline-phase composition of freeze-dried corrosion solids was analyzed using X-ray diffraction, and ferrous and ferric iron contents were determined via multiple extraction methods. Batch experiments demonstrated that trichloronitromethane (TCNM), a non-regulated DBP, is rapidly reduced in the presence of pipe corrosion solids and that dissolved oxygen (DO) slows the reaction. The water-soluble iron content of the pipe solids is the best predictor of TCNM reaction rate constant. These results indicate that highly reactive DBPs that are able to compete with oxygen and residual disinfectant for ferrous iron may be attenuated via abiotic reduction in drinking water distribution systems. PMID:18207489

Lee, Jeong-Yub; Pearson, Carrie R; Hozalski, Raymond M; Arnold, William A

2008-04-01

346

Water pollution: Pesticides in Aquatic environments. (Latest citations from Pollution abstracts). Published Search  

SciTech Connect

The bibliography contains citations concerning the physicochemical and biochemical dynamics of pesticides in aquatic environments. The effects of organophosphorus, organochlorine, and arsenical pesticides on marine, surface, and groundwater ecosystems are discussed. Topics include biological fate and transformation of pesticides in waters, sources of release and transport of pesticides, bioaccumulation and metabolism of pesticides by aquatic organisms, ecological concentration and degradability of pesticides in model ecosystems, and marine ecology. Guidelines for pesticide registration and pesticide effluents are also referenced. (Contains a minimum of 205 citations and includes a subject term index and title list.)

Not Available

1993-01-01

347

[Study of multi-residue method for determining pesticide residues in processed foods manufactured from agricultural products by LC-MS/MS].  

PubMed

A rapid multi-residue method for determination of pesticide residues in processed foods manufactured from agricultural products was examined. Five mL water was added to 5 g sample in a polypropylene tube, and the tube was left to stand at room temperature for 30 min. Then, 20 mL acetonitrile was added to the sample. The mixture was homogenized in a high-speed homogenizer, followed by salting out with 1 g NaCl and 4 g anhydrous MgSO4. After centrifugation, the organic layer was purified on a graphitized carbon/PSA cartridge column. After removal of the solvent, the extract was resolved in methanol-water and analyzed with LC-MS/MS. The recoveries of 93 pesticides fortified into 5 kinds of processed foods [Chinese cabbage kimchi, marmalade, raisin, umeboshi (pickled plum) and worcester sauce] were examined at the concentrations of 0.02 and 0.1 ?g/g (n=5). The recoveries of 61 pesticides in all foods were 70-120% with relative standard deviation below 20% at both concentrations. Seventy-four processed foods obtained from markets in Japan were examined with this method. Pesticide residues over the maximum residue limit (0.01 ?g/g) were detected in 2 processed foods. PMID:24389475

Fukui, Naoki; Takatori, Satoshi; Kitagawa, Yoko; Okihashi, Masahiro; Kajimura, Keiji; Obana, Hirotaka

2013-01-01

348

Refined methodology for the determination of neonicotinoid pesticides and their metabolites in honey bees and bee products by liquid chromatography-tandem mass spectrometry (LC-MS/MS).  

PubMed

An analytical method was refined for the extraction and determination of neonicotinoid pesticide residues and their metabolites in honey bees and bee products. Samples were extracted with 2% triethylamine (TEA) in acetonitrile (ACN) followed by salting out, solid phase extraction (SPE) cleanup, and detection using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The method was validated in triplicate at three fortification concentrations in each matrix. Good recoveries were observed for most analytes and ranged between 70 and 120% with relative standard deviations between replicates of <20% in most cases. The method limits of detection were 0.2 ng/g for the parent neonicotinoid pesticides and ranged between 0.2 and 15 ng/g for the neonicotinoid metabolites. This refined method provides lower detection limits and improved recovery of neonicotinoids and their metabolites, which will help researchers evaluate subchronic effects of these pesticides, address data gaps related to colony collapse disorder (CCD), and determine the role of pesticides in pollinator decline. PMID:20163114

Kamel, Alaa

2010-05-26

349

Degradation of blood group antigens in human colon ecosystems. I. In vitro production of ABH blood group-degrading enzymes by enteric bacteria.  

PubMed Central

Human feces contain enzymes produced by enteric bacteria that degrade the A, B, and H blood group antigens of gut mucin glycoproteins. We have studied their production in fecal cultures to determine if such cultures can be a source for enzyme purification and to explore how blood group antigen-degrading enzymes are adapted in individual human colon ecosystems. They were present in fecal cultures from each of 27 healthy subjects, including ABH nonsecretors. Heat-sensitive obligate anaerobes are their major source. From 39 to 85% of the total enzyme activity produced by growing cultures was extracellular. Commercial hog gastric mucin and salivary glycoproteins, including Lea saliva which lacks A, B, and H antigens, enhance production of A-, B-, and H-degrading activity in anaerobic fecal cultures irrespective of the glycoprotein's blood group specificity. There is evidence that the host's ABO blood type and secretor status affects the specificity of blood group-degrading enzymes produced by his fecal bacteria in vitro. Thus, fecal inocula from B secretors incubated with hog gastric mucin (A and H specificity) or with Lea saliva produced greater levels of B-degrading than A- or H-degrading activity, and inocula from A secretors in similar media produced greater levels of A-degrading than B- or H-degrading activity. Blood group-degrading enzymes produced in fecal cultures are glycosidases and not proteases. The B-degrading enzyme cleaves the B antigenic determinant alpha-D-galactose from the oligosaccharide side chains of mucin glycoproteins with B specificity. Anaerobic fecal cultures containing blood group substances are a feasible source for purifying blood group antigen-degrading enzymes. Prior adaptation to blood group antigens in the gut mucins of type A and type B secretors affects the specificity of the enzymes produced in vitro.

Hoskins, L C; Boulding, E T

1976-01-01

350

Analysis of atrazine and four degradation products in the pore water of the vadose zone, central Indiana  

USGS Publications Warehouse

A new method is described for the analysis of atrazine and four of its degradation products (desethylatrazine, deisopropylatrazine, didealkylatrazine, and hydroxyatrazine) in water. This method uses solid- phase extraction on a graphitized carbon black cartridge, derivatization of the eluate with N-methyl-N-(tert-butyldimethylsilyl)trifluoroacetamide (MTBSTFA), and analysis by gas chromatography/mass spectrometry (GC/MS). This method was used to analyze lysimeter samples collected from a field in central Indiana in 1994 and 1995. Atrazine and its degradation products were transported rapidly through the vadose zone. Maximum values of atrazine ranged from 2.61 to 8.44 ??g/L and occurred from 15 to 57 days after application. Maximum concentrations of the degradation products occurred from 11 to 140 days after atrazine application. The degradation products were more persistent than atrazine in pore water. Desethylatrazine was the dominant degradation product detected in the first year, and didealkylatrazine was the dominant degradation product detected in the second year. Concentrations of atrazine and the degradation products sorbed onto soil were estimated; maximum concentrations ranged from 7.3 to 24 ??g/kg for atrazine and were less than 5 ??g/kg for all degradation products. Degradation of atrazine and transport of all five compounds were simulated by the vadose zone flow model LEACHM. LEACHM was run as a Darcian-flow model and as a non-Darcian-flow model.

Panshin, S. Y.; Carter, D. S.; Bayless, E. R.

2000-01-01

351

Degradation and adsorption of selected pharmaceuticals and personal care products (PPCPs) in agricultural soils.  

PubMed

Pharmaceuticals and personal care products (PPCPs) are emerging contaminants in the environment, which have drawn popular concerns recently. Most studies on the environmental fate of PPCPs have focused on their behaviors during wastewater treatment processes, in aquatic environments, and in the sludge, however, little is known about their behavior in agricultural soils. In this study, adsorption and degradation of six selected PPCPs, including clofibric acid, ibuprofen, naproxen, triclosan, diclofenac and bisphenol A have been investigated in the laboratory using four US agricultural soils associated with reclaimed wastewater reuse. Adsorption test using a batch equilibrium method demonstrated that adsorption of all tested chemicals in soils could be well described with Freundlich equation, and their adsorption affinity on soil followed the order of triclosan>bisphenol A>clofibric acid>naproxen>diclofenac>ibuprofen. Retardation factor (R(F)) suggested that ibuprofen had potential to move downward with percolating water, while triclosan and bisphenol A were readily retarded in soils. Degradation of selected PPCPs in soils generally followed first-order exponential decay kinetics, with half-lives ranging from 0.81 to 20.44 d. Degradation of PPCPs in soils appeared to be influenced by the soil organic matter and clay contents. Sterilization generally decreased the degradation rates, indicating microbial activity played a significant role in the degradation in soils. The degradation rate constant decreased with increasing initial chemical concentrations in soil, implying that the microbial activity was inhibited with high chemical loading levels. PMID:19853275

Xu, Jian; Wu, Laosheng; Chang, Andrew C

2009-11-01

352

Metabolic labeling of RNA uncovers principles of RNA production and degradation dynamics in mammalian cells  

PubMed Central

Regulation of RNA levels is determined through the interplay between RNA production, processing and degradation. However, since most global studies of RNA regulation do not distinguish the separate contributions of these processes, relatively little is known about how they are temporally integrated to determine changes in RNA levels. In particular, while some studies emphasize the role of changes in the rate of transcription, others suggest a prominent involvement of time-varying degradation rates. Here, we combine metabolic labeling of RNA at high temporal resolution with advanced RNA quantification assays and computational modeling to estimate RNA transcription and degradation rates during the model response of immune dendritic cells (DCs) to pathogens. We find that changes in transcription rates determine the majority of temporal changes in RNA levels, but that changes in degradation rate are important for shaping sharp ‘peaked’ responses. Furthermore, transcription rate changes precede corresponding changes in RNA level by a small lag (15-30 min), which is shorter for induced than for repressed genes. We used massively parallel sequencing of the newly-transcribed RNA population – including non-polyadenylated transcripts – to estimate constant RNA degradation and processing rates. We find that temporally constant degradation rates vary significantly between genes and contribute substantially to the observed differences in the dynamic response, and that specific groups of transcripts, mostly cytokines and transcription factors, are undergoing faster mRNA maturation. Our study provides a new quantitative approach to study key steps in the integrative process of RNA regulation.

Rabani, Michal; Levin, Joshua Z; Fan, Lin; Adiconis, Xian; Raychowdhury, Raktima; Garber, Manuel; Gnirke, Andreas; Nusbaum, Chad; Hacohen, Nir; Friedman, Nir; Amit, Ido; Regev, Aviv

2011-01-01

353

Degradation characteristics of some Sudanese forages and tree pods using in sacco and gas production techniques  

Microsoft Academic Search

Fourteen Sudanese plant species were studied for their degradation characteristics, using nylon bag and gas production techniques. With the latter technique, all plant species were either treated with polyethylene glycol (PEG) to remove the phenolic anti-nutritional factors or left untreated. The plant species included four grasses, five legumes and four tree pod species. Grass and legume forages were collected during

M. M. M. Ahmed; F. M. El-Hag

2004-01-01

354

Role of Myelofibrosis in Hematotoxicity of Munitions RDX Environmental Degradation Product MNX.  

National Technical Information Service (NTIS)

The purpose of this research is to determine mechanisms through which hexahydro-1-nitroso- 3,5-dinitro-1,3,5-triazine (MNX), environmental degradation product of high energetic munition hexahydro-1,3,5-trinitro-1,3,5- triazine (RDX), causes persistent ane...

S. A. Meyer

2007-01-01

355

Detecting and quantifying lewisite degradation products in environmental samples using arsenic speciation  

SciTech Connect

This report describes a unique method for identifying and quantifying lewisite degradation products using arsenic (III) and arsenic (IV) speciation in solids and in solutions. Gas chromatographic methods, as well as high-performance liquid chromatographic methods are described for separation of arsenic species. Inductively coupled plasma-mass spectrographic methods are presented for the detection of arsenic.

Bass, D.A.; Yaeger, J.S.; Kiely, J.T.; Crain, J.S.; Shem, L.M.; O`Neill, H.J.; Gowdy, M.J. [Argonne National Lab., IL (United States); Besmer, M.; Mohrman, G.B. [Rocky Mountain Arsenal, Commerce City, CO (United States)

1995-12-31

356

Two layer segmentation for handling pathological motion in degraded post production media  

Microsoft Academic Search

The paper presents a mechanism for dealing with incorrect motion estimation in degraded post production image sequences. This tends to be caused by pathological motion (a combination of motion blur, complex foreground motion, shadows, etc.). We describe a method for estimating where such regions are likely to occur by segmenting sequences into foreground and background motion. We show it is

Benjamin Kent; Anil C. Kokaram; Bill Collis; Simon Robinson

2004-01-01

357

CO 2 production from degraded woods via a novel integrated pyrolysis-combustion process  

Microsoft Academic Search

The process of combustion produces minimal amounts of CO2 for conventional radiocarbon dating, making it difficult to estimate the age of the archaeological wood. Thus, the objective of this paper is to introduce a novel integrated pyrolysis-combustion process that will maximize the production of CO2. Degraded wood samples were assumed to be archaeological samples for this study, namely Karas (Aquilaria

N. Othman; S. K. Kamarudin; S. R. S. Abdullah; Z. Yaakob

2009-01-01

358

Role of Myelofibrosis in Hematotoxicity of Munitions RDX Environmental Degradation Product MNX.  

National Technical Information Service (NTIS)

The purpose of this research is to determine mechanisms through which hexahydro-1-nitroso- 3,5-dinitro-1,3,5-triazine (MNX), environmental degradation product of munition hexahydro-1,3,5- trinitro-1,3,5-triazine (RDX), causes anemia after acute exposure i...

S. A. Meyer

2009-01-01

359

Nonphosphate Degradation Products of Tributyl Phosphate and Their Reactivities in Purex Media Under Extreme Conditions  

Microsoft Academic Search

The chemical degradation of tributyl phosphate (TBP) in liquid systems, where TBP was in contact with aqueous solutions containing nitric acid and\\/or uranyl nitrate, was studied experimentally to clarify the mechanisms of the formation and successive reactions of nonphosphate products under atmospheric pressure. Butyl nitrate, propionic acid, acetic acid, butric acid, and butyl alcohol were formed as the nonphosphate butyl

Yoshikazu Tashiro; Ryuji Kodama; Hiroshi Sugai; Katsuhiko Suzuki; Shingo Matsuoka

2000-01-01

360

Emulsions stabilized by precipitates of zirconium and tributyl phosphate degradation products  

Microsoft Academic Search

In the Purex process, a solvent extraction method of nuclear fuel reprocessing, a stable emulsion called crud forms at the interface between the oil and water phases. This paper reports that crud is an emulsion stabilized by finely dispersed solids. Insoluble residues and precipitates of zirconium and radiation-degraded products of tributyl phosphate (TBP) are key materials in crud formation. Cruds

H. Sugai; K. Munakata; S. Miyachi; S. Yasu

1992-01-01

361

Glucose degradation products downregulate ZO-1 expression in human peritoneal mesothelial cells: the role of VEGF  

Microsoft Academic Search

Background. Glucose degradation products (GDPs) are formed during heat sterilization of peritoneal dialysis fluid and, to a lesser extent, during their prolonged storage. In vitro studies have demonstrated that GDPs impair functions of peritoneal mesothelial cells, including proliferation, viability and cytokine release. In the present study, we studied the acute effect of GDPs on the expression of tight junction-associated protein,

Joseph C. K. Leung; Loretta Y. Y. Chan; Felix F. K. Li; Sydney C. W. Tang; Kwok Wa Chan; Tak Mao Chan; Man Fai Lam; Anders Wieslander; Kar Neng Lai

362

Soil degradation under long-term rice production in Northeast Thailand  

Microsoft Academic Search

So degradation issues are assum ng increas ng importance in Northeast Thailand and are challenging the concept of sustainab ity of current land management systems. In th s study, the impacts of and converslon from natural Dipterocarp forest and wetland to agricu tural production on soil chemcal properties are compared. Soil samp es were collected at '10 cm ncrements to

Sawaeng Ruaysoongnern; Andrew D. Nobe

363

Fibrin degradation product D-dimer in the diagnosis of pulmonary embolism  

Microsoft Academic Search

Summary The study objective was to determine the specificity and sensitivity of plasma concentrations of D-dimer, a fibrin degradation product, as a marker for ongoing thrombotic and thrombolytic events in pulmonary embolism. A prospective study was performed in 74 patients with suspected pulmonary embolism who appeared in the emergency room with dyspnea and\\/or chest pain.

J. Lichey; I. Reschofski; T. Dissmann; M. Priesnitz; M. Hoffmann; H. Lode

1991-01-01

364

Toxicity of degradation products of the antifouling biocide pyridine triphenylborane to marine organisms.  

PubMed

We evaluated the acute toxicities of the main degradation products of pyridine triphenylborane (PTPB), namely, diphenylborane hydroxide (DPB), phenylborane dihydroxide (MPB), phenol, and biphenyl, to the alga Skeletonema costatum, the crustacean Tigriopus japonicus, and two teleosts, the red sea bream Pagrus major and the mummichog Fundulus heteroclitus. DPB was the most toxic of the degradation products to all four organisms. The acute toxicity values of DPB for S. costatum, T. japonicus, red sea bream, and mummichog were 55, 70, 100, and 200-310 ?g/L, respectively. The degradation products were less toxic than PTPB to S. costatum and T. japonicus; however, the toxicities of DPB and PTPB to the fish species were similar. We also examined changes in the inhibition of growth rate of S. costatum as well as the percentage of immobilization of T. japonicus as end points of toxicity of PTPB after irradiation of PTPB with 432 ± 45 W/m(2) of 290-700 nm wavelength light. After 7 days of irradiation with this light, the concentration of PTPB in the test solutions decreased markedly. A decrease in toxic effects closely coincided with the decrease in the concentration of PTPB caused by the irradiation. PTPB probably accounted for most of the toxicity in the irradiation test solutions. Because the concentrations of PTPB that were acutely toxic to S. costatum and T. japonicus were <10 % of the corresponding concentrations of its degradation products, PTPB probably accounted for most of the toxicity in the irradiation test solutions. PMID:23929384

Onduka, Toshimitsu; Ojima, Daisuke; Ito, Mana; Ito, Katsutoshi; Mochida, Kazuhiko; Fujii, Kazunori

2013-11-01

365

Identification and determination of metabolites and degradation products of sulfonamide antibiotics  

Microsoft Academic Search

Sulfonamide residues have been detected in all kinds of environmental water matrix. However, little attention has been so far paid to their metabolites and degradation products, and very few articles have included them in their analytical scope. The main goal of this article is to review those research studies in which both parent drugs and their respective metabolites have been

Damià Barceló; M SILVIADIAZCRUZ

2008-01-01

366

Determination of soman and VX degradation products by an aspiration ion mobility spectrometry  

Microsoft Academic Search

An aspiration type ion mobility spectrometry (IMS) has been used to determine chemical warfare agent (CWA) degradation products from liquid samples. This technique is based on ion mobility which depends on the molecular weight, charge and shape. With this method, it is possible to measure the mobility distribution of positive and negative ion clusters simultaneously in six different electrodes. Each

Kai Tuovinen; Heikki Paakkanen; Osmo Hänninen

2001-01-01

367

Selective extraction of organophosphorus nerve agent degradation products by molecularly imprinted solid-phase extraction  

Microsoft Academic Search

The analysis of alkyl alkylphosphonic acids, the degradation products of V and G nerve agents as VX, Sarin or Soman, is an important task for the verification of compliance to the Chemical Weapons Convention. The detection of these contaminants at low concentration levels is often difficult in complex matrices due to the amount of interfering substances. Molecularly imprinted solid-phase extraction

Sophie Le Moullec; Arlette Bégos; Valérie Pichon; Bruno Bellier

2006-01-01

368

A Strategic Analysis of Product Recalls: The Role of Moral Degradation and Organizational Control  

Microsoft Academic Search

abstract? Although product recalls are neither new nor unique to China, China bears much of the bitter criticism from the media and negative reactions from the public. This essay discusses the reasons behind recalls from a moral degradation perspective, grounded in the larger framework of anomie theory. While making remarkable economic progress, China is also moving toward a society with

Yadong Luo

2008-01-01

369

Composition stability and degradation products of selected materials for solar heating and cooling  

Microsoft Academic Search

The composition, stability and thermal degradation products of a variety of structural plastics, heat transfer fluids, thermal storage media and sealants, which have been proposed for use in solar heating and cooling applications, were either defined generically by analysis or obtained by surveying the literature. This information will be used to aid in the assessment of the environmental impact of

C. Arnold Jr.; R. E. Trujillo

1979-01-01

370

HYDROLOGIC CONDITIONS AFFECTING THE TROPOSPHERIC FLUX OF VINCLOZOLIN AND ITS DEGRADATION PRODUCTS  

EPA Science Inventory

A laboratory chamber was used to determine hydrologic conditions that lead to the tropospheric flux of a suspected anti-androgenic dicarboximide fungicide, vinclozolin (3-(3,5-dichlorophenyl)-5-methyl-5-vinyl-oxzoli-dine-2,4-dione) and three degradation products from sterilized...

371

Stimulation of aryl metabolite production in the basidiomycete Bjerkandera sp. strain BOS55 with biosynthetic precursors and lignin degradation products  

Microsoft Academic Search

Aryl metabolites are known to have an important role in the ligninolytic system of white rot fungi. The addition of known precursors and aromatic acids representing lignin degradation products stimulated the production of aryl metabolites (veratryl alcohol, veratraldehyde, p-anisaldehyde, and 3-chloro-p-anisaldehyde) in the white rot fungus Bjerkandera sp. strain BOS55. The presence of manganese (Mn) is known to inhibit the

TUNDE MESTER; HENK J. SWARTS; I. Romero; S. Sole; Bont de J. A. M; J. A. Field

1997-01-01

372

RP-HPLC stability-indicating assay method for talinolol and characterization of its degradation products.  

PubMed

A reversed-phase high-performance liquid chromatographic method is developed and validated for the quantitative determination of talinolol and to characterize its degradation products. A very good resolution between peaks is achieved using a C18 column at 40°C. The mobile phase comprises of a mixture of acetonitrile and potassium dihydrogen orthophosphate buffer (pH 4.4) in the ratio of 27:73 (v/v). The method is validated with respect to linearity, accuracy, precision, robustness, and forced degradation studies, which further proved the stability indicating power. During the forced degradation studies, talinolol is observed to be labile to hydrolytic stress and thermal stress (in the solution form). However, it is stable to the oxidative, photolytic, and thermal stress (in the solid form). The degraded products formed are investigated by electrospray ionization (ESI), time-of-flight mass spectrometry, nuclear magnetic resonance, and infrared spectroscopy. A possible degradation pathway is outlined based on the results. The method is found to be sensitive with a detection limit of 0.125 ?g/mL and a quantitation limit of 0.378 ?g/mL. The method is also demonstrated to be robust, as it is resistant to small variations of chromatographic variables such as pH, mobile phase composition, flow rate, and column temperature. PMID:22080807

Sinha, V R; Ghai, Damanjeet

2011-01-01

373

Antiglycation and Antioxidant Effect of Carnosine against Glucose Degradation Products in Peritoneal Mesothelial Cells  

Microsoft Academic Search

Background\\/Aim:Toxicity with advanced glycation end products (AGEs) is a major problem in uremic patients. Treatment with peritoneal dialysis (PD) exacerbates AGE formation as a result of bioincompatibility of the conventional peritoneal dialysis fluid (PDF). The presence of glucose degradation products (GDPs) in PDF is the main cause of its bioincompatibility. Carnosine is an endogenous dipeptide with a powerful antiglycation\\/antioxidant activity.

Mohamed-Saiel Saeed Alhamdani; Abdul-Hameed A.-M. Al-Kassir; Fawzi K. H. Abbas; Nidham A. Jaleel; Maha F. Al-Taee

2007-01-01

374

Degradation products formed during UV exposure of polyethylene–ZnO nano-composites  

Microsoft Academic Search

Photodegradation of low density polyethylene (LDPE) containing nano-particulate ZnO has been studied using FTIR to follow the development of oxidation products in the polymer film and to monitor carbon dioxide evolved as a principal product of oxidation. The degradation behaviour of ZnO-free LDPE has been compared with that of compounds containing 0.25% and 0.75% ZnO and these results are compared

Rui Yang; P. A. Christensen; T. A. Egerton; J. R. White

2010-01-01

375

The influence of lignin degradation products on xylose fermentation by Klebsiella pneumoniae  

Microsoft Academic Search

The inhibitory effects of seven closely related lignin degradation products on xylose fermentation by Klebsiella pneumoniae were studied. Compounds were added in varying concentrations. Less heavily substituted phenolics (at concentrations of, 0.1–0.4 g\\/l) were more inhibitory to growth and solvent production than vanillyl or syringyl derivatives. All of the cultures recovered from this inhibition after a prolonged incubation period. When

Nora K. Nishikawa; Roger Sutcliffe; John N. Saddler

1988-01-01

376

75 FR 8340 - Maneb; Product Cancellation Order of a Certain Pesticide Registration  

Federal Register 2010, 2011, 2012, 2013

...registration identified in Table 1 is hereby canceled...product identified in Table 1 in a manner inconsistent with any...product identified in Table 1, until March 10...existing stocks must be in a manner consistent with the...

2010-02-24

377

75 FR 8942 - Maneb; Product Cancellation Order for Certain Pesticide Registrations  

Federal Register 2010, 2011, 2012, 2013

...registrations identified in Table 1 are hereby canceled...products identified in Table 1 in a manner inconsistent with any...products identified in Table 1 until exhausted. Any...existing stocks must be in a manner consistent with the...

2010-02-26

378

Premature Translational Termination Products Are Rapidly Degraded Substrates for MHC Class I Presentation  

PubMed Central

Nearly thirty percent of all newly synthesized polypeptides are targeted for rapid proteasome-mediated degradation. These rapidly degraded polypeptides (RDPs) are a source of antigenic substrates for the MHC class I presentation pathway, allowing for immunosurveillance of newly synthesized proteins by cytotoxic T lymphocytes. Despite the recognized role of RDPs in MHC I presentation, it remains unclear what molecular characteristics distinguish RDPs from their more stable counterparts. It has been proposed that premature translational termination products may constitute a form of RDP; indeed, in prokaryotes translational drop-off products are normal by-products of protein synthesis and are subsequently rapidly degraded. To study the cellular fate of premature termination products, we used the antibiotic puromycin as a means to experimentally manipulate prematurely terminated polypeptide production in human cells. At low concentrations, puromycin enhanced flux into rapidly degraded polypeptide pools, with small polypeptides being markedly more labile then high molecular weight puromycin adducts. Immunoprecipitation experiments using anti-puromycin antisera demonstrated that the majority of peptidyl-puromycins are rapidly degraded in a proteasome-dependent manner. Low concentrations of puromycin increased the recovery of cell surface MHC I-peptide complexes, indicating that prematurely terminated polypeptides can be processed for presentation via the MHC I pathway. In the continued presence of puromycin, however, MHC I export to the cell surface was inhibited, coincident with the accumulation of polyubiquitinated proteins. The time- and dose-dependent effects of puromycin suggest that the pool of peptidyl-puromycin adducts differ in their targeting to various proteolytic pathways that, in turn, differ in the efficiency with which they access the MHC I presentation machinery. These studies highlight the diversity of cellular proteolytic pathways necessary for the metabolism and immunosurveillance of prematurely terminated polypeptides that are, by their nature, highly heterogeneous.

Lacsina, Joshua R.; Marks, Odessa A.; Liu, Xiongfei; Reid, David W.; Jagannathan, Sujatha; Nicchitta, Christopher V.

2012-01-01

379

Decontaminating pesticide protective clothing.  

PubMed

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

Laughlin, J

1993-01-01

380

Supercritical fluid chromatography as a method of analysis for the determination of 4-hydroxybenzylglucosinolate degradation products.  

PubMed

In the present study analytical and preparative supercritical fluid chromatography (SFC) were used for investigation of myrosinase catalysed degradation of 4-hydroxybenzylglucosinolate (sinalbin). Sinalbin occurs as a major glucosinolate in seeds of Sinapis alba L., in various mustards and other food products. The degradation products were identified and quantified by analysis based on a developed SFC method using a bare silica column. Determinations comprised transformation products of sinalbin, produced both during degradation of isolated sinalbin, and during autolysis of meal from S. alba seeds. The conditions in the developed SFC method were used as basis for the preparative SFC procedure applied for isolation of the components prior to their identification by nuclear magnetic resonance (NMR) spectroscopy. Myrosinase catalysed sinalbin hydrolysis resulted in the reactive 4-hydroxybenzyl isothiocyanate as an initial product at pH values from 3.5 to 7.5 whereas 4-hydroxybenzyl cyanide was one of the major products at low pH values. 4-Hydroxybenzyl isothiocyanate was found to disappear from the aqueous reaction mixtures in a few hours, as it reacted easily with available nucleophilic reagents. 4-Hydroxybenzyl alcohol was found as the product from reaction with water, and with ascorbic acid, 4-hydroxybenzylascorbigen was produced. PMID:10869674

Buskov, S; Hasselstrøm, J; Olsen, C E; Sørensen, H; Sørensen, J C; Sørensen, S

2000-07-01

381

Relationship between lignin degradation and production of reduced oxygen species by Phanerochaete chrysosporium  

SciTech Connect

The relationship between the production of reduced oxygen species, hydrogen peroxide (H/sub 2/O/sub 2/), superoxide (O/sub 2//sup -/), and hydroxyl radical (.OH), and the oxidation of synthetic lignin to CO/sub 2/ was studied in whole cultures of the white-rot fungus Phanerochaete chrysosporium Burds. The kinetics of the synthesis of H/sub 2/O/sub 2/ coincided with the appearance of the ligninolytic system; also, H/sub 2/O/sub 2/ production was markedly enhanced by growth under 100% O/sub 2/, mimicing the increase in ligninolytic activity characteristic of cultures grown under elevated oxygen tension. Lignin degradation by whole cultures was inhibited by a specific H/sub 2/O/sub 2/ scavenger, catalase, implying a role for H/sub 2/O/sub 2/ in the degradative process. Superoxide dismutase also inhibited lignin degradation, suggesting that O/sub 2//sup -/ is also involved in the breakdown of lignin. The production of .OH was assayed in whole cultures by a benzoate decarboxylation assay. Neither the kinetics of .OH synthesis nor the final activity of its producing system obtained under 100% O/sub 2/ correlated with that of the lignin-degrading system. However, lignin degradation was inhibited by compounds which react with .OH. It is concluded that H/sub 2/O/sub 2/, and perhaps O/sub 2//sup -/, are involved in lignin degradation; because these species are relatively unreactive per se, their role must be indirect. Conclusions about a role for .OH in ligninolysis could not be reached. (Refs. 28).

Faison, B.D.; Kirk, T.K.

1983-11-01

382

Increased Reactive Oxygen Species Production in the Brain After Repeated Low-Dose Pesticide Paraquat Exposure in Rats. A Comparison with Peripheral Tissues  

Microsoft Academic Search

The pesticide paraquat (PQ) was found to be a suitable xenobiotic to model Parkinson’s disease. The reactive oxygen species\\u000a (ROS) production was suggested to be the main cause of PQ toxicity but very few evidences were found for its generation in\\u000a the brain in vivo after ip administration. We compared the effects of PQ-induced ROS generation between the brain structures

Katarzyna Kuter; Przemys?aw Nowak; Krystyna Go?embiowska; Krystyna Ossowska

2010-01-01

383

Degradation of cyanidin 3-glucoside by caffeic acid o-quinone. Determination of the stoichiometry and characterization of the degradation products.  

PubMed

Caffeic acid o-quinone (CQ) was prepared by oxidation of caffeic acid with o-chloranil in organic media. The reaction between the purified CQ and cyanidin 3-glucoside (Cy 3-glc, o-diphenolic anthocyanin) was monitored by HPLC, and quantitative analyses were performed to establish the stoichiometry of the reaction. The results indicate that Cy 3-glc is degraded by a coupled oxidation mechanism with integration of CQ into the degradation products. The ratio of degraded Cy 3-glc to CQ incorporated into the condensation products was approximately 2.0. No brown products could be detected, only a slight orange color. Moreover, the addition of purified polyphenol oxidase to the slightly colored media resulted in the disappearance of the caffeic acid formed from the reaction of coupled oxidation (Cy 3-glc/CQ) and the formation of brown polymers. The degradation products were isolated by gel filtration on Sephadex G-25. The UV-vis spectra and chemical analysis (acidic hydrolysis) of the degradation products suggest that they resulted from the condensation of caffeic acid and Cy 3-glc. HPLC analysis showed that the partial purified fraction contained a mixture of complex condensation products. PMID:10552861

Kader, F; Irmouli, M; Zitouni, N; Nicolas, J P; Metche, M

1999-11-01

384

Sustainable agricultural practices: energy inputs and outputs, pesticide, fertilizer and greenhouse gas management.  

PubMed

The food security issue was addressed by the development of "modern agriculture" in the last century. But food safety issues and environment degradation were the consequences suffered as a result. Climate change has been recognized as the result of release of stored energy in fossil fuel into the atmosphere. Homogeneous crop varieties, machinery, pesticides and fertilizers are the foundation of uniform commodities in modern agriculture. Fossil fuels are used to manufacture fertilizers and pesticides as well as the energy source for agricultural machinery, thus characterizes modern agriculture. Bio-fuel production and the possibility of the agriculture system as a form of energy input are discussed. PMID:19965338

Wang, Yue-Wen

2009-01-01

385

A validated stability-indicating RP-HPLC method for levofloxacin in the presence of degradation products, its process related impurities and identification of oxidative degradant.  

PubMed

The objective of current study was to develop a validated specific stability indicating reversed-phase liquid chromatographic method for the quantitative determination of levofloxacin as well as its related substances determination in bulk samples, pharmaceutical dosage forms in the presence of degradation products and its process related impurities. Forced degradation studies were performed on bulk sample of levofloxacin as per ICH prescribed stress conditions using acid, base, oxidative, water hydrolysis, thermal stress and photolytic degradation to show the stability indicating power of the method. Significant degradation was observed during oxidative stress and the degradation product formed was identified by LCMS/MS, slight degradation in acidic stress and no degradation was observed in other stress conditions. The chromatographic method was optimized using the samples generated from forced degradation studies and the impurity spiked solution. Good resolution between the peaks corresponds to process related impurities and degradation products from the analyte were achieved on ACE C18 column using the mobile phase consists a mixture of 0.5% (v/v) triethyl amine in sodium dihydrogen orthophosphate dihydrate (25 mM; pH 6.0) and methanol using a simple linear gradient. The detection was carried out at 294 nm. The limit of detection and the limit of quantitation for the levofloxacin and its process related impurities were established. The stressed test solutions were assayed against the qualified working standard of levofloxacin and the mass balance in each case was in between 99.4 and 99.8% indicating that the developed LC method was stability indicating. Validation of the developed LC method was carried out as per ICH requirements. The developed LC method was found to be suitable to check the quality of bulk samples of levofloxacin at the time of batch release and also during its stability studies (long term and accelerated stability). PMID:19632800

Lalitha Devi, M; Chandrasekhar, K B

2009-12-01

386

Chemical and photochemical degradation of chlorantraniliprole and characterization of its transformation products.  

PubMed

This study aimed at assessing the photodegradation of the insecticide chlorantraniliprole (CAP) in deionized water and in tap water amended with humic acids and nitrate. Photolysis was carried out under simulated solar or UV-A light. CAP (39 ?M) photodegradation was slightly faster in tap water than in deionized water with half lives of 4.1 and 5.1 days, respectively. Photodegradation rate of CAP was hardly affected by humic acids (up to 100 mg L(-1)) and nitrate. Photodegradation pattern was different in slightly acidic (pH=6.1) deionized water compared to basic (pH=8.0) tap water. Four main degradation products have been isolated and characterized spectroscopically, and crystal structure was recorded for the first two photodegradation products. CAP also degraded in the dark controls, but only at basic pH (23% loss at pH 8.0 in tap water after 6 days), resulting in the formation of one single degradation product. Our study shows that the degradation of chlorantraniliprole in water is a combination of chemical and photochemical reactions, which are highly dependent on the pH of the solution. PMID:24125717

Lavtižar, Vesna; van Gestel, Cornelis A M; Dolenc, Darko; Trebše, Polonca

2014-01-01

387

Characterization of radiolytically generated degradation products in the strip section of a TRUEX flowsheet  

SciTech Connect

This report presents a summary of the work performed to meet the FCRD level 2 milestone M3FT-13IN0302053, “Identification of TRUEX Strip Degradation.” The INL radiolysis test loop has been used to identify radiolytically generated degradation products in the strip section of the TRUEX flowsheet. These data were used to evaluate impact of the formation of radiolytic degradation products in the strip section upon the efficacy of the TRUEX flowsheet for the recovery of trivalent actinides and lanthanides from acidic solution. The nominal composition of the TRUEX solvent used in this study is 0.2 M CMPO and 1.4 M TBP dissolved in n-dodecane and the nominal composition of the TRUEX strip solution is 1.5 M lactic acid and 0.050 M diethylenetriaminepentaacetic acid. Gamma irradiation of a mixture of TRUEX process solvent and stripping solution in the test loop does not adversely impact flowsheet performance as measured by stripping americium ratios. The observed increase in americium stripping distribution ratios with increasing absorbed dose indicates the radiolytic production of organic soluble degradation compounds.

Dean R. Peterman; Lonnie G. Olson; Gary S. Groenewold; Rocklan G. McDowell; Richard D. Tillotson; Jack D. Law

2013-08-01

388

Degradation of the synthetic dye amaranth by the fungus Bjerkandera adusta Dec 1: inference of the degradation pathway from an analysis of decolorized products.  

PubMed

We examined the degradation of amaranth, a representative azo dye, by Bjerkandera adusta Dec 1. The degradation products were analyzed by high performance liquid chromatography (HPLC), visible absorbance, and electrospray ionization time-of-flight mass spectroscopy (ESI-TOF-MS). At the primary culture stage (3 days), the probable reaction intermediates were 1-aminonaphthalene-2,3,6-triol, 4-(hydroxyamino) naphthalene-1-ol, and 2-hydroxy-3-[2-(4-sulfophenyl) hydrazinyl] benzenesulfonic acid. After 10 days, the reaction products detected were 4-nitrophenol, phenol, 2-hydroxy-3-nitrobenzenesulfonic acid, 4-nitrobenzene sulfonic acid, and 3,4'-disulfonyl azo benzene, suggesting that no aromatic amines were created. Manganese-dependent peroxidase activity increased sharply after 3 days culture. Based on these results, we herein propose, for the first time, a degradation pathway for amaranth. Our results suggest that Dec 1 degrades amaranth via the combined activities of peroxidase and hydrolase and reductase action. PMID:21526388

Gomi, Nichina; Yoshida, Shuji; Matsumoto, Kazutsugu; Okudomi, Masayuki; Konno, Hiroki; Hisabori, Toru; Sugano, Yasushi

2011-11-01

389

78 FR 15949 - Notice of Receipt of Request To Voluntarily Cancel Certain Pesticide Registrations  

Federal Register 2010, 2011, 2012, 2013

...Notice of Receipt of Request To Voluntarily Cancel Certain Pesticide Registrations AGENCY...requests by a registrant to voluntarily cancel certain pesticide registrations. EPA...requests from Spectrum Group (Spectrum) to cancel five pesticide products registered...

2013-03-13

390

78 FR 12313 - Notice of Receipt of Requests To Voluntarily Cancel Certain Pesticide Registrations  

Federal Register 2010, 2011, 2012, 2013

...the chemical industry; pesticide users; and members of the...distribution, or use of pesticides. B. What should I consider...from registrants to cancel 25 pesticide products registered under...Pendulum 3.3 Herbicide........

2013-02-22

391

78 FR 35265 - Notice of Receipt of Requests To Voluntarily Cancel Certain Pesticide Registrations  

Federal Register 2010, 2011, 2012, 2013

...the chemical industry; pesticide users; and members of the...distribution, or use of pesticides. B. What should I consider...from registrants to cancel 54 pesticide products registered under...Liberty ATZ Herbicide.. Atrazine,...

2013-06-12

392

76 FR 55385 - Notice of Receipt of Requests To Voluntarily Cancel Certain Pesticide Registrations  

Federal Register 2010, 2011, 2012, 2013

...the chemical industry; pesticide users; and members of the...distribution, or use of pesticides. If you have any questions...from registrants to cancel 32 pesticide products registered under...MCPA,2-ethylhexyl ester, Herbicide. Bromoxynil octanoate....

2011-09-07

393

Biodegradation of Leonardite by an alkali-producing bacterial community and characterization of the degraded products.  

PubMed

In this study, three bacterial communities were obtained from 12 Leonardite samples with the aim of identifying a clean, effective, and economic technique for the dissolution of Leonardite, a type of low-grade coal, in the production of humic acid (HA). The biodegradation ability and characteristics of the degraded products of the most effective bacterial community (MCSL-2), which degraded 50% of the Leonardite within 21 days, were further investigated. Analyses of elemental composition, (13)C NMR, and Fourier transform infrared revealed that the contents of C, O, and aliphatic carbon were similar in biodegraded humic acid (bHA) and chemically (alkali) extracted humic acid (cHA). However, the N and carboxyl carbon contents of bHA was higher than that of cHA. Furthermore, a positive correlation was identified between the degradation efficiency and the increasing pH of the culture medium, while increases of manganese peroxidase and esterase activities were also observed. These data demonstrated that both alkali production and enzyme reactions were involved in Leonardite solubilization by MCSL-2, although the former mechanism predominated. No fungus was observed by microscopy. Only four bacterial phylotypes were recognized, and Bacillus licheniformis-related bacteria were identified as the main group in MCSL-2 by analysis of amplified 16S rRNA genes, thus demonstrating that Leonardite degradation ability has a limited distribution in bacteria. Hormone-like bioactivities of bHA were also detected. In this study, a bacterial community capable of Leonardite degradation was identified and the products characterized. These data implicate the use of such bacteria for the exploitation of Leonardite as a biofertilizer. PMID:22075634

Gao, Tong-Guo; Jiang, Feng; Yang, Jin-Shui; Li, Bao-Zhen; Yuan, Hong-Li

2012-03-01

394

Identification and Description of Chemical Deactivation/Detoxification Methods for the Safe Disposal of Selected Pesticides.  

National Technical Information Service (NTIS)

This sequel to the Handbook for Pesticide Disposal by Common Chemical Methods has examined chemical detoxification/degradation methods for 40 pesticides. The objectives for this study are the same as described in the companion: to develop practical chemic...

S. S. Lande

1978-01-01

395

PESTICIDE ROOT ZONE MODEL (PRZM): A PROCEDURE FOR EVALUATING PESTICIDE LEACHING THREATS TO GROUNDWATER  

EPA Science Inventory

A continuous simulation model that considers interactions of pesticides in surface runoff (in water and on eroded sediment, advection in percolating water, molecular diffusion, dispersion, uptake by plants, sorption to soil, and biological and chemical degradation) is described. ...

396

Method for determination of methyl tert-butyl ether and its degradation products in water  

USGS Publications Warehouse

An analytical method is described that can detect the major alkyl ether compounds that are used as gasoline oxygenates (methyl tert-butyl ether, MTBE; ethyl tert-butyl ether, ETBE; and tert-amyl methyl ether, TAME) and their most characteristic degradation products (tert-butyl alcohol, TBA; tert-butyl formate, TBF; and tert-amyl alcohol, TAA) in water at sub-ppb concentrations. The new method involves gas chromatography (GC) with direct aqueous injection (DAI) onto a polar column via a splitless injector, coupled with detection by mass spectrometry (MS). DAI-GC/MS gives excellent agreement with conventional purge-and-trap methods for MTBE over a wide range of environmentally relevant concentrations. The new method can also give simultaneous identification of polar compounds that might occur as degradation products of gasoline oxygenates, such as TBA, TBF, TAA, methyl acetate, and acetone. When the method was applied to effluent from a column microcosm prepared with core material from an urban site in New Jersey, conversion of MTBE to TBA was observed after a lag period of 35 days. However, to date, analyses of water samples from six field sites using the DAI-GC/MS method have not produced evidence for the expected products of in situ degradation of MTBE.An analytical method is described that can detect the major alkyl ether compounds that are used as gasoline oxygenates (methyl tert-butyl ether, MTBE; ethyl tert-butyl ether, ETBE; and tert-amyl methyl ether, TAME) and their most characteristic degradation products (tert-butyl alcohol, TBA; tert-butyl formate, TBF; and tert-amyl alcohol, TAA) in water at sub-ppb concentrations. The new method involves gas chromatography (GC) with direct aqueous injection (DAI) onto a polar column via a splitless injector, coupled with detection by mass spectrometry (MS). DAI-GC/MS gives excellent agreement with conventional purge-and-trap methods for MTBE over a wide range of environmentally relevant concentrations. The new method can also give simultaneous identification of polar compounds that might occur as degradation products of gasoline oxygenates, such as TBA, TBF, TAA, methyl acetate, and acetone. When the method was applied to effluent from a column microcosm prepared with core material from an urban site in New Jersey, conversion of MTBE to TBA was observed after a lag period of 35 days. However, to date, analyses of water samples from six field sites using the DAI-GC/MS method have not produced evidence for the expected products of in situ degradation of MTBE.

Church, C. D.; Isabelle, L. M.; Pankow, J. F.; Rose, D. L.; Tratnyek, P. G.

1997-01-01

397

Study of degradation intermediates formed during electrochemical oxidation of pesticide residue 2,6-dichlorobenzamide (BAM) at boron doped diamond (BDD) and platinum-iridium anodes.  

PubMed

Electrochemical oxidation is a promising technique for degradation of otherwise recalcitrant organic micropollutants in waters. In this study, the applicability of electrochemical oxidation was investigated concerning the degradation of the groundwater pollutant 2,6-dichlorobenzamide (BAM) through the electrochemical oxygen transfer process with two anode materials: Ti/Pt90-Ir10 and boron doped diamond (Si/BDD). Besides the efficiency of the degradation of the main pollutant, it is also of outmost importance to control the formation and fate of stable degradation intermediates. These were investigated quantitatively with HPLC-MS and TOC measurements and qualitatively with a combined HPLC-UV and HPLC-MS protocol. 2,6-Dichlorobenzamide was found to be degraded most efficiently by the BDD cell, which also resulted in significantly lower amounts of intermediates formed during the process. The anodic degradation pathway was found to occur via substitution of hydroxyl groups until ring cleavage leading to carboxylic acids. For the BDD cell, there was a parallel cathodic degradation pathway that occurred via dechlorination. The combination of TOC with the combined HPLC-UV/MS was found to be a powerful method for determining the amount and nature of degradation intermediates. PMID:24873711

Madsen, Henrik Tækker; Søgaard, Erik Gydesen; Muff, Jens

2014-08-01

398

Fate of CL-20 in sandy soils: degradation products as potential markers of natural attenuation.  

PubMed

Hexanitrohexaazaisowurtzitane (CL-20) is an emerging explosive that may replace the currently used explosives such as RDX and HMX, but little is known about its fate in soil. The present study was conducted to determine degradation products of CL-20 in two sandy soils under abiotic and biotic anaerobic conditions. Biotic degradation was prevalent in the slightly acidic VT soil, which contained a greater organic C content, while the slightly alkaline SAC soil favored hydrolysis. CL-20 degradation was accompanied by the formation of formate, glyoxal, nitrite, ammonium, and nitrous oxide. Biotic degradation of CL-20 occurred through the formation of its denitrohydrogenated derivative (m/z 393 Da) while hydrolysis occurred through the formation of a ring cleavage product (m/z 156 Da) that was tentatively identified as CH(2)=N-C(=N-NO(2))-CH=N-CHO or its isomer N(NO(2))=CH-CH=N-CO-CH=NH. Due to their chemical specificity, these two intermediates may be considered as markers of in situ attenuation of CL-20 in soil. PMID:18801604

Monteil-Rivera, Fanny; Halasz, Annamaria; Manno, Dominic; Kuperman, Roman G; Thiboutot, Sonia; Ampleman, Guy; Hawari, Jalal

2009-01-01

399

Fenton and Fenton-like oxidation of pesticide acetamiprid in water samples: kinetic study of the degradation and optimization using response surface methodology.  

PubMed

The aims of this study were (a) to evaluate the degradation of acetamiprid with the use of Fenton reaction, (b) to investigate the effect of different concentrations of H2O2 and Fe(2+), initial pH and various iron salts, on the degradation of acetamiprid and (c) to apply response surface methodology for the evaluation of degradation kinetics. The kinetic study revealed a two-stage process, described by pseudo- first and second order kinetics. Different H2O2:Fe(2+) molar ratios were examined for their effect on acetamiprid degradation kinetics. The ratio of 3 mg L(-1) Fe(2+): 40 mg L(-1) H2O2 was found to completely remove acetamiprid at less than 10 min. Degradation rate was faster at lower pH, with the optimal value at pH 2.9, while Mohr salt appeared to degrade acetamiprid faster. A central composite design was selected in order to observe the effects of Fe(2+) and H2O2 initial concentration on acetamiprid degradation kinetics. A quadratic model fitted the experimental data, with satisfactory regression and fit. The most significant effect on the degradation of acetamiprid, was induced by ferrous iron concentration followed by H2O2. Optimization, aiming to minimize the applied ferrous concentration and the process time, proposed a ratio of 7.76 mg L(-1) Fe(II): 19.78 mg L(-1) H2O2. DOC is reduced much more slowly and requires more than 6h of processing for 50% degradation. The use to zero valent iron, demonstrated fast kinetic rates with acetamiprid degradation occurring in 10 min and effective DOC removal. PMID:23871596

Mitsika, Elena E; Christophoridis, Christophoros; Fytianos, Konstantinos

2013-11-01

400

78 FR 55695 - Notice of Receipt of Pesticide Products; Registration Applications To Register New Uses  

Federal Register 2010, 2011, 2012, 2013

...Crop Protection, Stine-Haskell Research Center, P.O. Box 30, Newark, DE 19714. Active ingredient: Chlorantraniliprole. Product Type: Insecticide. Proposed Uses: Tree Nut Group 14-12, and Stone Fruit Group 12-12...

2013-09-11

401

77 FR 59186 - Notice of Receipt of Pesticide Products; Registration Applications To Register New Uses  

Federal Register 2010, 2011, 2012, 2013

...Crop Protection, Stine-Haskell Research Center, P.O. Box 30, Newark, DE 19714. Active ingredient: Chlorantraniliprole. Product Type: Insecticide. Proposed Uses: Cereal grain group 15, except rice; forage, fodder;...

2012-09-26

402

78 FR 9389 - Notice of Receipt of Pesticide Products; Registration Applications To Register New Uses  

Federal Register 2010, 2011, 2012, 2013

...Forchlorfenuron. Product Type: Plant Growth Regulator. Proposed Uses: Almond; cherry, sweet fig; pear; pistachio; plum; and prune. Contact: Cynthia Giles-Parker, RD, (703) 305-7740, email address: giles-parker.cynthia@epa.gov. List...

2013-02-08

403

78 FR 64937 - Pesticide Products; Registration Applications for New Active Ingredients  

Federal Register 2010, 2011, 2012, 2013

...a Wholly Owned Subsidiary of Ashland, Inc., 5500 Blazer Parkway, Dublin, OH 43017. Active ingredient: Ammonium Carbamate. Product type: Antimicrobial. Proposed uses: Paper mill process water and re-circulating cooling water systems....

2013-10-30

404

77 FR 66836 - Notice of Receipt of Pesticide Products; Registration Applications  

Federal Register 2010, 2011, 2012, 2013

...92507. Active ingredient: Biochemical Pheromone (Mating Disruptor) with Carob Moth Pheromone Mimic (7,9,11-Dodecatrien-1-ol, formate at 90.8%. Product Type: Pheromone (Mating Disruptor). Proposed Uses:...

2012-11-07

405

Interaction between vine pesticides and bovine serum albumin studied by nuclear spin relaxation data.  

PubMed

Pesticides are chemicals usually used in agriculture to prevent possible diseases to crops, such as grapes, caused by parasites. Even if most of the pesticides are degraded during the wine process, residual levels remain in the final product. The most commonly used pesticides in vine belong to several classes of chemical compounds; among them, triazoles and anilinopyrimidines have been commercially used since the 1970s and 1990s, respectively. In this work, we investigated the interaction between three of the most used fungicides belonging to the chemical classes mentioned above (myclobutanil, triadimenol, and pyrimethanil) and bovine serum albumin (BSA) by nuclear spin relaxation analysis. We found that all of the pesticides were able to form a complex with BSA; nevertheless, there were strong differences in their affinity toward the plasma protein. The nuclear magnetic resonance approach used on the basis of the analysis of selective relaxation rate enhancements of pesticide protons in the presence of BSA allowed for the calculation of the affinity indexes and the equilibrium constants of the three systems. Myclobutanil showed the highest affinity toward BSA, whereas triadimenol gave the weakest interaction with the protein. The differences in the capacity of the three pesticides to bind to albumin highlighted the existence of different binding strengths on the protein. These results indicate that myclobutanil and triadimenol, despite their structure similarity, may have very different residence times in the plasma and rates of clearance. PMID:20857906

Martini, Silvia; Bonechi, Claudia; Rossi, Claudio

2010-10-13

406

[Determination of the trace residues of four organochlorine pesticides in agricultural products by high performance liquid chromatography with modified multi-walled carbon nanotubes as solid phase extraction adsorbent].  

PubMed

A novel method for the simultaneous determination of the trace residues of four organochlorine pesticides such as p,p'-DDD, p,p'-DDT, o,p'-DDT and p,p'-DDE in agricultural products by multi-walled carbon nanotubes (MWNTs) modified by acid oxidation on the surface as solid phase extraction (SPE) adsorbent coupled with high performance liquid chromatography (HPLC) was developed. The effects of the surface acid oxidation, SPE operations and HPLC conditions on the determination of the four pesticide residues were investigated. Under the optimized experimental conditions, the novel method provided wide linear ranges for the pesticides with correlation coefficients of 0. 997 8 - 0. 999 5, the detection limit was 0.050 mg/L for each pesticides. The recoveries from the samples spiked with the pesticide standards at three concentration levels of 0.10, 2.0 and 50 mg/L were in the range of 78% - 104% with the relative standard deviations (RSDs) of 2.7% -7.6%. This study indicated the MWNTs SPE was an efficient clean-up method to agricultural products (included dried orange peel, ginseng, cabbage and tea). The proposed method showed the advantages of accuracy and sensitivity, and can meet the requirements for the determination of low residue pesticide in agricultural products. The study provides a useful method for the analysis of trace substance of agricultural products. PMID:23285982

Peng, Xiaojun; Pang, Jinshan; Deng, Aihua; Liang, Weihua; Liang, Youzhen; Wen, Qijing

2012-09-01

407

Identification and functional characteristics of chlorpyrifos-degrading and plant growth promoting bacterium Acinetobacter calcoaceticus.  

PubMed

A bacterial strain D10 with strong ability of degrading chlorpyrifos was isolated from rhizosphere of chives contaminated with pesticide. It was found that it's capable of utilizing chlorpyrifos as the sole source of carbon for growth, and within the first 4 days the extent of degradation at initial concentration of 100?mg?L(-1) was 60.0%. It also showed a high ability of degrading chlorpyrifos in sterilized soil, and the degradation reached up to 60.2% after 18 days. In addition, the strain D10 also showed multiple plant growth-promoting traits of phosphate solubilization, indole-3-acetic acid and siderophore production. The results indicate that the strain D10 has potential in the application of pesticide-degrading and plant growth promotion. Strain D10 was identified as Acinetobacter calcoaceticus based on its morphological, physiological-biochemical properties and the 16S rRNA sequence analysis. PMID:23712768

Zhao, Lei; Wang, Fei; Zhao, Jiao

2014-05-01

408

Buthionine sulfoximine diverts the melanogenesis pathway toward the production of more soluble and degradable pigments.  

PubMed

Buthionine sulfoximine (BSO) is a specific inhibitor of ?-glutamylcysteine synthetase, thus blocking the synthesis of glutathione (GSH). It is known that this makes that BSO affects melanin synthesis because of the role of thiols in melanogenesis. However, BSO may also react with the intermediate oxidation products of melanogenesis, a possibility that has not been investigated from the initial steps of the pathway. We created in vitro conditions simulating eumelanogenesis (oxidation of l-DOPA in the absence of GSH) and pheomelanogenesis (oxidation of l-DOPA in the presence of GSH) under presence or absence of BSO. BSO made that eumelanogenesis results in pigments more soluble and less resistant to degradation by hydrogen peroxide than pigments obtained without BSO. A similar but less marked effect was observed for pheomelanogenesis only at subsaturating concentrations of GSH. These results suggest that BSO diverts the melanogenesis pathway toward the production of more soluble and degradable pigments. PMID:24703231

Galván, Ismael; Wakamatsu, Kazumasa; Alonso-Alvarez, Carlos; Solano, Francisco

2014-05-01

409

Strategies for quantification and confirmation of multi-class polar pesticides and transformation products in water by LC–MS 2 using triple quadrupole and hybrid quadrupole time-of-flight analyzers  

Microsoft Academic Search

Liquid chromatography–tandem mass spectrometry (LC–MS2) is an excellent technique for the determination of polar pesticides and transformation products in water. On-line trace enrichment by solid-phase extraction (SPE)-LC in combination with MS2 satisfies most analytical demands of modern laboratories for pesticide-residue analysis, with respect to sensitivity (limits of detection and limits of quantification at sub-?g\\/L levels), selectivity, reliability and rapidity, and

Félix Hernández; Óscar J. Pozo; Juan V. Sancho; Francisco J. López; José M. Marín; María Ibáñez

2005-01-01

410

Efficacy of D-Dimer and Total Fibrin Degradation Products Evaluation in Suspected Pulmonary Embolism  

Microsoft Academic Search

Three different assays for fïbrin\\/fibrinogen degradation products (FDP) were evaluated in patients with suspected pulmonary embolism (PE) as rapid screening tests with the aim of evaluating whether they could be used either as a substitute of ventilation\\/perfusion lung scanning or to supplement scintigraphy in patients in whom the scan was inconclusive (low or intermediate probability). D-Dimer by enzyme-linked immunosorbent assay

Julio Flores; Carmen Lancha; Esteban Pérez Rodríguez; Angel García Avello; Elena Bollo; Luis Javier García Frade

1995-01-01

411

Effects of Variations in Grass Protein Fractions and Degradation Rates on Metabolizable Protein Allowable Milk Production  

Microsoft Academic Search

Jonker, J.S., Fox, D.G., Chase, L.E. and Cherney, D.J.R. 2001 Effects of variations in grass protein fractions and degradation rates on metabolizable protein allowable milk production. J. Appl. Anim. Res., 20: 189–196.Effects of variation of grass forage protein fractions (soluble intake protein, acid detergent fibre insoluble protein and neutral detergent fibre insoluble protein), as measured from producer submitted, samples over

J. S. Jonker; D. G. Fox; L. E. Chase; D. J. R. Cherney

2001-01-01

412

Production of native-starch-degrading enzymes by a Bacillus firmus\\/lentus strain  

Microsoft Academic Search

A bacterium belonging to the Bacillus firmus\\/lentus-complex and capable of growth on native potato starch was isolated from sludge of a pilot plant unit for potato-starch production. Utilization of a crude enzyme preparation obtained from the culture fluid after growth of the microorganism on native starch, resulted in complete degradation of native starch granules from potato, maize and wheat at

Dirk-Jan Wijbenga; Gerrit Beldman; Anko Veen; Doede J. Binnema

1991-01-01

413

The analysis of sterol degradation products to detect vegetable fats in chocolate  

Microsoft Academic Search

A method for the detection of hydrocarbon sterol degradation products (sterenes) has been adapted for the analysis of noncocoa\\u000a butter vegetable fats in chocolate. The method involves solvent extraction of the fat separation of the sterene fraction,\\u000a and analysis of individual sterenes with mass spectrometric detection. The sterene composition of refined noncocoa vegetable\\u000a fats was determined in samples of cocoa

C. Crews; R. Calvet-Sarrett; P. Brereton

1997-01-01

414

Fibrin degradation products in the serum and cerebrospinal fluid of patients with group A meningococcal meningitis.  

PubMed

Forty-one patients suffering from group A meningococcal meningitis in an area within the epidemic meningococcal belt of tropical West Africa were studied. The serum of only two of these patients contained fibrin degradation products (FDPs). The cerebrospinal fluid of 21 of these cases was also examined for FDPs, which were present in 13. Their presence in the cerebrospinal fluid was associated with a poor prognosis. PMID:4212012

Brueton, M J; Tugwell, P; Whittle, H C; Greenwood, B M

1974-05-01

415

Fibrin degradation products in the serum and cerebrospinal fluid of patients with group A meningococcal meningitis  

PubMed Central

Forty-one patients suffering from group A meningococcal meningitis in an area within the epidemic meningococcal belt of tropical West Africa were studied. The serum of only two of these patients contained fibrin degradation products (FDPs). The cerebrospinal fluid of 21 of these cases was also examined for FDPs, which were present in 13. Their presence in the cerebrospinal fluid was associated with a poor prognosis.

Brueton, M. J.; Tugwell, P.; Whittle, H. C.; Greenwood, B. M.

1974-01-01

416

Identification, isolation and characterization of potential degradation product in risperidone tablets  

Microsoft Academic Search

One unknown impurity (degradation product) present at a level below 0.1% in the initial samples increased to a level of 0.5% in 6M\\/40°C\\/75% RH stability samples of risperidone tablets was detected by gradient reverse-phase high-performance liquid chromatography (HPLC). This impurity was isolated using reverse-phase preparative liquid chromatography. Based on the spectral data the structure of this impurity is characterized as

Ch. Bharathi; D. Krishnama Chary; M. Saravana Kumar; Rama Shankar; V. K. Handa; Ramesh Dandala; A. Naidu

2008-01-01

417

Detection of simulants and degradation products of chemical warfare agents by vibrational spectroscopy  

Microsoft Academic Search

This work was focused in the measurement of spectroscopic signatures of Chemical Warfare Agent Simulants (CWAS) and degradation products of chemical agents using vibrational spectroscopy for the generation of spectroscopic libraries. The chemicals studied were: DMMP, DIMP, 2-CEES, 2-BAET, 1,4-thioxane, thiodiglycol sulfoxide, dihexylamine, cyclohexylamine, among others. Raman microscopy experiments were performed at different excitation wavelengths that spanned from NIR at

Orlando Ruiz-Pesante; Leonardo C. Pacheco-Londoño; Oliva M. Primera-Pedrozo; William Ortiz; Yadira M. Soto-Feliciano; Deborah E. Nieves; Michael L. Ramirez; Samuel P. Hernández-Rivera

2007-01-01

418

Spatial and Temporal Variations in Chitinolytic Gene Expression and Bacterial Biomass Production during Chitin Degradation  

Microsoft Academic Search

Growth of the chitin-degrading marine bacterium S91 on solid surfaces under oligotrophic conditions was accompanied by the displacement of a large fraction of the surface-derived bacterial production into the flow- ing bulk aqueous phase, irrespective of the value of the surface as a nutrient source. Over a 200-h period of surface colonization, 97 and 75% of the bacterial biomass generated

ACE M. BATY; CALLIE C. EASTBURN; SOMKIET TECHKARNJANARUK; AMANDA E. GOODMAN; GILL G. GEESEY

2000-01-01

419

Fate and transport of pesticides in the ground water systems of southwest Georgia, 1993-2005  

USGS Publications Warehouse

Modern agricultural practices in the United States have resulted in nearly unrivaled efficiency and productivity. Unfortunately, there is also the potential for release of these compounds to the environment and consequent adverse affects on wildlife and human populations. Since 1993, the National Water-Quality Assessment (NAWQA) program of the U.S. Geological Survey has evaluated water quality in agricultural areas to address these concerns. The objective of this study is to evaluate trends in pesticide concentrations from 1993-2005 in the surficial and Upper Floridan aquifers of southwest Georgia using pesticide and pesticide degradate data collected for the NAWQA program. There were six compounds - five herbicides and one degradate - that were detected in more than 20% of samples: atrazine, deethylatrazine (DEA), metolachlor, alachlor, floumeturon, and tebuthiuron. Of the 128 wells sampled during the study, only eight wells had pesticide concentrations that either increased (7) or decreased (1) on a decadal time scale. Most of the significant trends were increasing concentrations of pesticides in older water; median pesticide concentrations did not differ between the surficial and Upper Floridan aquifers from 1993 and 2005. Deethylatrazine, in the Upper Floridan aquifer, was the only compound that had a significant change (increase) in concentration during the study. The limited number of wells with increases in pesticide concentrations suggest that ground-water sources of these compounds are not increasing in concentration over the time scale represented in this study. Copyright ?? 2008 by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America. All rights reserved.

Dalton, M. S.; Frick, E. A.

2008-01-01

420

Utilization of Ganglioside-Degrading Paenibacillus sp. Strain TS12 for Production of Glucosylceramide  

PubMed Central

Gangliosides, sialic acid-containing glycosphingolipids, are membrane constituents of vertebrates and are known to have important roles in cellular differentiation, adhesion, and recognition. We report here the isolation of a bacterium capable of degrading gangliotetraose-series gangliosides and a new method for the production of glucosylceramide with this bacterium. GM1a ganglioside was found to be sequentially degraded by Paenibacillus sp. strain TS12, which was isolated from soil, as follows: GM1a ? asialo GM1 ? asialo GM2 ? lactosylceramide ? glucosylceramide. TS12 was found to produce a series of ganglioside-degrading enzymes, such as sialidases, ?-galactosidases, and ?-hexosaminidases. TS12 also produced ?-glucosidases, but glucosylceramide was somewhat resistant to the bacterial enzyme under the conditions used. Taking advantage of the specificity, we developed a new method for the production of glucosylceramide using TS12 as a biocatalyst. The method involves the conversion of crude bovine brain gangliosides to glucosylceramide by coculture with TS12 and purification of the product by chromatography with Wakogel C-300 HG.

Sumida, Tomomi; Sueyoshi, Noriyuki; Ito, Makoto

2002-01-01

421

Health aspects of organophosphorous pesticides in asian countries.  

PubMed

Organophosphorous (OP) pesticides are used frequently in agriculture, particularly in Asian countries over the past decades. Poisoning by these agents, either as acute or chronic in these nations, is a serious health problem. OP pesticides residue in fruits and vegetables that may not induce early clinical features, could also affect the human health. Therefore, medical and health professionals should be aware and learn more on the toxicology, prevention and proper management of OP poisoning. The well-known mechanism of OP toxicity is the inhibition of acetyl cholinesterase, resulting in an accumulation of acetylcholine and continued stimulation of acetylcholine receptors. Therefore, they are also called anticholinesterase agents. Determination of blood acetyl cholinesterase and butyryl cholinesterase activities remains a mainstay for the rapid initial screening of OP pesticides. Quantitative analysis of OP and their degradation products in plasma and urine by mass spectrometric methods is a more specific method, but is expensive and limited to specialized laboratories. Therefore, history of OP pesticides exposure and clinical manifestations of a cholinergic syndrome is sufficient for management of the exposed patients. However, electrophysiological tests may be required for the diagnosis of delayed neuropathy of OP poisoning. The standard management of OP poisoning includes decontamination, atropine sulphate with an oxime. Recent advances focus on blood alkalinisation and magnesium sulphate as promising adjunctive therapies. Preventive measures in OP exposure are of great importance in human health in developing countries. Therefore, regulations and controls on safe use of OP particularly in Asian countries are recommended. PMID:23304659

Balali-Mood, M; Balali-Mood, K; Moodi, M; Balali-Mood, B

2012-01-01

422

Potential for abiotic reduction of pesticides in Prairie pothole porewaters.  

PubMed

Prairie pothole lakes (PPLs) are critical hydrological and ecological components of central North America and represent one of the largest inland wetland systems on Earth. These lakes are located within an agricultural region, and many of them are subject to nonpoint-source pesticide pollution. Limited attention, however, has been paid to understanding the impact of PPL water chemistry on the fate and persistence of pesticides. In this study, the abiotic reductive transformation of seven dinitroaniline pesticides was investigated in PPL sediment porewaters containing naturally abundant levels of reduced sulfur species (i.e., bisulfide (HS(-)) and polysulfides (S(n)(2-))) and dissolved organic matter (DOM). Target dinitroanilines underwent rapid degradation in PPL porewaters and were transformed into corresponding amine products. While the largest fraction of the transformation could be attributed to reduced sulfur species, experimental evidence suggested that other reactive entities in PPL porewaters, such as DOM and mineral phases, might also affect the reaction rates of dinitroanilines. Results from this study highlight the importance of reductive transformation as an abiotic natural attenuation pathway for pesticides entering the PPL sedimentary environment. PMID:22313175

Zeng, Teng; Chin, Yu-Ping; Arnold, William A

2012-03-20

423

64 FR 33550 - National Emission Standards for Hazardous Air Pollutants: Pesticide Active Ingredient Production  

Federal Register 2010, 2011, 2012, 2013

...manufacturing or processing, comes into direct contact with, or results from, the production...or quench organic vapor streams through direct contact; and condensed steam from jet...25 of appendix A of 40 CFR part 60 for direct measurement of an effluent with a...

1999-06-23

424

60 FR 64282 - Worker Protection Standard; Labeling Revisions Required for Pesticide Products within the Scope...  

Federal Register 2010, 2011, 2012, 2013

...labeling can be presented in two formats: 1. Single-product...compliance with the Worker Protection Standard (40 CFR Part 170...compliance with the Worker Protection Standard (40 CFR Part 170...labeling and with the Worker Protection Standard (40 CFR Part...distributors must develop separate brochures because...

1995-12-14

425

Organochlorine Pesticide Residues in Basic Food Products and Diets in the Republic of Belarus  

Microsoft Academic Search

Breast milk of women in Belarus is polluted with OC's, as reported earlier (Barkatina et al 1998). The investigation of OC's in basic food products used by the inhabitants of Belarus as well as the estimation of daily OC's intake based on the amount consumed per day in a usual diet was of great interest. The purpose of the present

E. N. Barkatina; A. L. Pertsovsky; V. I. Murokh; N. D. Kolomiets; O. V. Shulyakovskaya; O. N. Venger; V. I. Makarevich

1999-01-01

426

Dietary pesticide risk assessment.  

PubMed

In this review, the process of dietary pesticide risk assessment has been presented and three major components of the process--estimation of pesticide residue levels, estimation of food consumption patterns, and characterization of risk based on a comparison of exposure estimates with toxicological criteria--have been identified. Each component of the process is subject to considerable uncertainty that may compromise the accuracy of the final risk assessment. In estimating pesticide residue levels, common practices range from highly theoretical models assuming that all residues are present at a predetermined level (typically at the tolerance level) to the use of market basket survey data obtained at the time the food is ready for consumption. Intermediate techniques include using actual monitoring data (usually obtained from government residue enforcement programs) and/or making corrections to estimates on the basis of actual pesticide use. Additional corrections may be used to incorporate data on the effects of post-harvest practices such as processing, washing, cooking, peeling, and transportation that have often been shown to dramatically reduce residue levels, although occasional increases in residue levels and/or formation of toxicologically significant breakdown products may also result from post-harvest practices. Food consumption estimates are typically derived from national surveys of consumer food consumption behavior and are also subject to considerable uncertainty. Food consumption estimates are often disaggregated into distinct population subgroups based on age, gender, geographic region, and ethnicity, although the accuracy of estimates for particular subgroups is commonly questioned on the basis of the adequacy of sample size. At the present time, data from the 1977-78 Nationwide Food Consumption Survey are still being used, and the incorporation of more recent data from the 1987-88 Nationwide Food Consumption Survey is being delayed due to major flaws in the study. On occasion, other food consumption surveys may be used, although they are typically much smaller in scope than the 1977-78 and 1987-88 studies and are considered less reliable. The multiplication of residue level estimates by food consumption estimates yields an estimate of human pesticide exposure. Commonly, the theoretical maximum residue contribution (TMRC) is calculated that represents the maximum "legal" exposure to pesticides. Calculation of the TMRC involves the assumptions that all pesticides legally allowed on a particular commodity will always be applied, that all residues are present at the tolerance levels, and that there are no post-harvest effects on residue levels. Often the TMRC is used as a sorting tool by the EPA in its preliminary assessment of dietary risks to pesticides.(ABSTRACT TRUNCATED AT 400 WORDS) PMID:1631351

Winter, C K

1992-01-01

427

Bacterial degradation of chlorophenols and their derivatives.  

PubMed

Chlorophenols (CPs) and their derivatives are persistent environmental pollutants which are used in the manufacture of dyes, drugs, pesticides and other industrial products. CPs, which include monochlorophenols, polychlorophenols, chloronitrophenols, chloroaminophenols and chloromethylphenols, are highly toxic to living beings due to their carcinogenic, mutagenic and cytotoxic properties. Several physico-chemical and biological methods have been used for removal of CPs from the environment. Bacterial degradation has been considered a cost-effective and eco-friendly method of removing CPs from the environment. Several bacteria that use CPs as their sole carbon and energy sources have been isolated and characterized. Additionally, the metabolic pathways for degradation of CPs have been studied in bacteria and the genes and enzymes involved in the degradation of various CPs have been identified and characterized. This review describes the biochemical and genetic basis of the degradation of CPs and their derivatives. PMID:24589366

Arora, Pankaj Kumar; Bae, Hanhong

2014-01-01

428

Amine-degradation products play no part in corrosion at gas-sweetening plants  

SciTech Connect

Gas-sweetening units using diethanolamine (DEA) and methyldiethanolamine (MDEA) are occasionally subject to corrosion. Discounting the basic degradation products of DEA as the cause, researchers (1) confirmed the presence of formic, oxalic, and acetic acids in used amine solutions, (2) defined oxygen's role in forming these carboxylic acids, and (3) demonstrated that the acid contents of different units are about the same order of magnitude for both DEA and MDEA. In most cases, oxygen can be easily excluded from gas-treating units, especially in storage tanks, thereby limiting the formation of acid products.

Blanc, C.; Grall, M.; Demarais, G.

1982-11-15

429

Commercial opportunities for pesticides based on plant essential oils in agriculture, industry and consumer products  

Microsoft Academic Search

In spite of intensive research on plant natural products and insect-plant chemical interactions over the past three decades,\\u000a only two new types of botanical insecticides have been commercialized with any success in the past 15 years, those based on\\u000a neem seed extracts (azadirachtin), and those based on plant essential oils. Certain plant essential oils, obtained through\\u000a steam distillation and rich in

Murray B. Isman; Saber Miresmailli; Cristina Machial

2011-01-01

430

Protocol for an electrospray ionization tandem mass spectral product ion library: development and application for identification of 240 pesticides in foods.  

PubMed

Modern determination techniques for pesticides must yield identification quickly with high confidence for timely enforcement of tolerances. A protocol for the collection of liquid chromatography (LC) electrospray ionization (ESI)-quadruple linear ion trap (Q-LIT) mass spectrometry (MS) library spectra was developed. Following the protocol, an enhanced product ion (EPI) library of 240 pesticides was developed by use of spectra collected from two laboratories. A LC-Q-LIT-MS workflow using scheduled multiple reaction monitoring (sMRM) survey scan, information-dependent acquisition (IDA) triggered collection of EPI spectra, and library search was developed and tested to identify the 240 target pesticides in one single LC-Q-LIT MS analysis. By use of LC retention time, one sMRM survey scan transition, and a library search, 75-87% of the 240 pesticides were identified in a single LC/MS analysis at fortified concentrations of 10 ng/g in 18 different foods. A conventional approach with LC-MS/MS using two MRM transitions produced the same identifications and comparable quantitative results with the same incurred foods as the LC-Q-LIT using EPI library search, finding 1.2-49 ng/g of either carbaryl, carbendazim, fenbuconazole, propiconazole, or pyridaben in peaches; carbendazim, imazalil, terbutryn, and thiabendazole in oranges; terbutryn in salmon; and azoxystrobin in ginseng. Incurred broccoli, cabbage, and kale were screened with the same EPI library using three LC-Q-LIT and a LC-quadruple time-of-flight (Q-TOF) instruments. The library search identified azoxystrobin, cyprodinil, fludioxinil, imidacloprid, metalaxyl, spinosyn A, D, and J, amd spirotetramat with each instrument. The approach has a broad application in LC-MS/MS type targeted screening in food analysis. PMID:22686274

Zhang, Kai; Wong, Jon W; Yang, Paul; Hayward, Douglas G; Sakuma, Takeo; Zou, Yunyun; Schreiber, André; Borton, Christopher; Nguyen, Tung-Vi; Kaushik, Banerjee; Oulkar, Dasharath

2012-07-01

431

Early diagenetic degradation products of bacteriohopanepolyols produced by Rhodopseudomonas palustris strain TIE-1  

NASA Astrophysics Data System (ADS)

The anoxygenic purple non-sulphur bacterium Rhodopseudomonas palustris strain TIE-1 has emerged as an excellent model organism to study hopanoid biosynthesis and function. It produces several C30 hopanoids, tetrahymanol, as well as various bacteriohopanepolyols (BHPs). In addition, TIE-1 is capable of methylating various hopanoids and the non-hopanoid pentacyclic terpenoid tetrahymanol at C-2, which is rare among hopanoid producers. Here, the lipid inventory of TIE-1 under anoxic photoautotrophic growth conditions using either H2 or Fe(II) as electron donor was studied. Adenosylhopane, aminotriol and bacteriohopanetetrol (BHT) were abundant when TIE-1 was grown on H2, but aminotriol and BHT were only found in traces when grown with Fe(II). Only during growth on Fe(II), BHT was found with and without C-2 methylation (25% of both BHT homologues), whereas the other BHPs were not C-2 methylated independent of growth mode. In C30 hopanoids and tetrahymanol, C-2 methylated compounds accounted for as much as 59% of the respective C-2 methylated/non-methylated homologues during growth with Fe(II), but only up to 24% during growth with H2. This observation reveals that C-2 methylated hopanoids may have a specific function in TIE-1 and are preferably synthesized in response to elevated Fe(II) concentrations. Further, we exposed the bacterial cells of strain TIE-1 to elevated temperatures and pressure aiming to produce early degradation products of bacteriohopanepolyols (BHPs). While so far, only few BHPs such as 32,35-anhydrobacteriohopanetetrol (anhydroBHT) have been identified as early diagenetic degradation products, in our experiments bacteriohopanetetrol (BHT) and possibly adenosylhopane were degraded to various anhydroBHT isomers, and new N-containing degradation products were discovered and tentatively assigned as anhydroaminotriols.

Eickhoff, Merle; Birgel, Daniel; Talbot, Helen M.; Peckmann, Jörn; Kappler, Andreas

2014-05-01

432

TRANSFER EFFICIENCES OF PESTICIDES FROM HOUSEHOLD CERAMIC TILE TO FOODS  

EPA Science Inventory

Traditional assessments of pesticide exposure through diet have focused on contamination during production (e.g., pesticides in agriculture). However, recent residential monitoring studies have demonstrated that a significant portion of total exposure to infants and children ...

433

PESTICIDE TRANSFER EFFICIENCIES FROM HOUSEHOLD SURFACES TO FOODS  

EPA Science Inventory

Traditional dietary pesticide exposure assessments have focused on contamination during production (e.g., pesticides in agriculture). However, recent residential monitoring studies have demonstrated that a significant portion of infant and children's total exposure can result fr...

434

PERMEATION RESISTANCE OF GLOVE MATERIALS TO AGRICULTURAL PESTICIDES  

EPA Science Inventory

The toxicities of many agricultural pesticides require that hand protection be provided to persons who mix, load, and apply these products. he selection of appropriate handwear is particularly problematic for pesticides that contain organic solvents or active ingredients that beh...

435

Stability-indicating determination of rebamipide in the presence of its acid degradation products.  

PubMed

Four sensitive and precise stability-indicating methods for the determination of rebamipide (REB) in the presence of its acid-degradation products and in a pharmaceutical formulation were developed and validated. Method A used the first derivative of the ratio spectra (1DD) spectrophotometric method by measuring the peak amplitude at 249.4 nm (maximum) and at 259 nm (minimum), and at the total peak amplitude (from 249.4 to 259 nm, 1DD(249.4 + 259 nm)) in the range of 2-14 microg/mL. This method yielded mean recoveries of 99.87 +/- 0.83, 100.04 +/- 0.75, and 100.28 +/- 1.11%, respectively. Method B is a dual wavelength method, which allows the determination of REB in presence of its acid-degradation products by measuring the absorbance difference between 254 and 269 nm within a linearity range of 5-65 microg/mL; it showed a mean recovery of 99.84 +/- 1.06. Method C is a TLC