Sample records for pesticide degradation products

  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. Pesticides and pesticide degradation products in stormwater runoff: Sacramento River Basin, California

    USGS Publications Warehouse

    Domagalski, J.

    1996-01-01

    Pesticides in stormwater runoff, within the Sacramento River Basin, California, were assessed during a storm that occurred in January 1994. Two organophosphate insecticides (diazinon and methidathion), two carbamate pesticides (molinate and carbofuran), and one triazine herbicide (simazine) were detected. Organophosphate pesticide concentrations increased with the rising stage of the hydrographs; peak concentrations were measured near peak discharge. Diazinon oxon, a toxic degradation product of diazinon, made up approximately 1 to 3 percent of the diazinon load. The Feather River was the principal source of organophosphate pesticides to the Sacramento River during this storm. The concentrations of molinate and carbofuran, pesticides applied to rice fields during May and June, were relatively constant during and after the storm. Their presence in surface water was attributed to the flooding and subsequent drainage, as a management practice to degrade rice stubble prior to the next planting. A photodegradation product of molinate, 4-keto molinate, was in all samples where molinate was detected and made up approximately 50 percent of the total molinate load. Simazine, a herbicide used in orchards and to control weeds along the roadways, was detected in the storm runoff, but it was not possible to differentiate the two sources of that pesticide to the Sacramento River.

  3. 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...

  4. 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. ...

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

    PubMed

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

    2012-01-01

    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

  6. Degradation of pesticides by actinomycetes.

    PubMed

    De Schrijver, A; De Mot, R

    1999-01-01

    Actinomycetes have considerable potential for the biotransformation and biodegradation of pesticides. Members of this group of Gram-positive bacteria have been found to degrade pesticides with widely different chemical structures, including organochlorines, s-triazines, triazinones, carbamates, organophosphates, organophosphonates, acetanilides, and sulfonylureas. A limited number of these xenobiotic pesticides can be mineralized by single isolates, but often consortia of bacteria are required for complete degradation. Cometabolism of pesticides is frequently observed within this group of bacteria. When compared with pesticide degradation by Gram-negative bacteria, much less information about molecular mechanisms involved in biotransformations of pesticides by actinomycetes is available. Progress in this area has been seriously hampered by a lack of suitable molecular genetic tools for most representatives of this major group of soil bacteria. Overcoming this constraint would enable a better exploitation of the biodegradation and biotransformation abilities of actinomycetes for applications such as bioremediation and construction of transgenic herbicide-resistant crops. PMID:10405795

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

    Microsoft Academic Search

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

    2011-01-01

    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

  8. Pesticide Degradation in Thermal Foggers.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Thermal foggers are used in many parts of the world for vector control. Since thermal foggers use heat to create and help propel adulticide clouds, there is reason to examine the stability of pesticides in both diesel and water-based formulations. This study examined the degradation of 5 pesticide...

  9. 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...

  10. Evaluating pesticide degradation in the environment: blind spots and emerging opportunities.

    PubMed

    Fenner, Kathrin; Canonica, Silvio; Wackett, Lawrence P; Elsner, Martin

    2013-08-16

    The benefits of global pesticide use come at the cost of their widespread occurrence in the environment. An array of abiotic and biotic transformations effectively removes pesticides from the environment, but may give rise to potentially hazardous transformation products. Despite a large body of pesticide degradation data from regulatory testing and decades of pesticide research, it remains difficult to anticipate the extent and pathways of pesticide degradation under specific field conditions. Here, we review the major scientific challenges in doing so and discuss emerging opportunities to identify pesticide degradation processes in the field. PMID:23950532

  11. PESTICIDE PRODUCT INFORMATION SYSTEM (PPIS)

    EPA Science Inventory

    The Pesticide Product Information System (PPIS) contains information concerning all pesticide products registered in the United States. It includes registrant name and address, chemical ingredients, toxicity category, product names, distributor brand names, site/pest uses, pestic...

  12. Pesticides and degradation products in groundwaters from a vineyard region: optimization of a multiresidue method based on SPE and GC-MS.

    PubMed

    Herrero-Hernández, Eliseo; Pose-Juan, Eva; Alvarez-Martín, Alba; Andrades, María Soledad; Rodríguez-Cruz, María Sonia; Sánchez-Martín, María J

    2012-12-01

    A reliable multiresidue method based on solid phase extraction was developed using GC-MS to determine and quantify 34 pesticides, including herbicides, fungicides, insecticides, and some of their degradation products, in groundwater in a vineyard region of La Rioja (northern Spain). Different parameters were optimized and good recoveries (65-108% range) and precisions (12-19% range) were achieved with spiked water samples for a concentration of 0.1 ?g/L. The experimental results showed an excellent linearity (r(2) > 0.99) over the 0.1-1.5 ?g/L range. The detection limits of the proposed method were 1-37 ng/L for most of the compounds studied. The methodology has been successfully applied to the analysis of groundwater samples from vineyard areas in La Rioja and the presence of pesticides, especially fungicides and herbicides, at several concentration levels was revealed. Terbuthylazine, its metabolite desethyl-terbuthylazine, and fluometuron were the pesticides most frequently detected in higher concentrations. Overall and taking into consideration the European Union maximum residue limit of pesticides in groundwater, 16 of the 34 compounds included in this study were detected in concentrations over that limit in at least one of the samples analyzed. PMID:23225715

  13. Consumer Products Treated with Pesticides

    MedlinePLUS

    ... article (e.g., incorporation of a pesticide in paint). These treated products often make implied or explicit ... protect the article or substance itself (for example, paint treated with a pesticide to protect the paint ...

  14. Regulation of pesticide degradation in the detritusphere

    NASA Astrophysics Data System (ADS)

    Pagel, Holger; Poll, Christian; Ingwersen, Joachim; Ditterich, Franziska; Gebala, Aurelia; Kandeler, Ellen; Streck, Thilo

    2015-04-01

    The detritusphere is a microbial hot spot of C turnover and degradation of pesticides in soils. We aimed at an improved understanding of the regulation mechanisms, which are responsible for stimulated degradation of the herbicide MCPA (2-Methyl-4-chlorophenoxyacetic acid) in response to increased C availability in the detritusphere. We combined a microcosm experiment with biogeochemical modeling and linked genetic information on abundances of total bacteria, fungi and specific pesticide degraders in soil to the coupled biogeochemical dynamics of C and MCPA. As a result of diffusive and convective C transport from litter into the adjacent soil we found increased dissolved organic C (DOC) in soil up to a 6 mm distance to litter (detritusphere). In the detritusphere, we observed increased microbial C and accelerated MCPA degradation. These dynamics were accurately reproduced by the model. Whereas the observed increase of bacteria and pesticide degrader populations in the detritusphere was simulated satisfactorily, the model could not reproduce the steep increase of fungi indicated by the fungal marker gene. Our simulations suggest that bacterial MCPA degraders mostly benefited from high-quality DOC, whereas fungal activity and growth were specifically stimulated by low-quality DOC. According to the simulations, MCPA was predominantly degraded via fungal co-metabolism. Our study demonstrates that biogeochemical processes in soil hotspots are regulated by the interaction of transport processes and microbial dynamics. It further reveals that mathematical modelling is as powerful tool to gain comprehensive insight into the microbial regulation of matter cycling in soil. Genetic information has a high potential to parameterize and evaluate complex mechanistic models, but model approaches must be improved based on extended information on gene dynamics at the cellular level.

  15. 75 FR 34448 - Pesticides; Draft Guidance for Pesticide Registrants on False or Misleading Pesticide Product...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-17

    ...False or Misleading Pesticide Product Brand Names; Extension of Comment Period AGENCY...False or Misleading Pesticide Product Brand Names.'' This document extends the comment...False or Misleading Pesticide Product Brand Names.'' EPA is hereby extending the...

  16. Household Products Database: Pesticides

    MedlinePLUS

    ... More Resources Browse Pesticides Category Pesticides activator algaecide ants ants & roaches ants, roaches aphids bed bugs beetles berries birds brush control bulbs carpenter ants caterpillars crabgrass control deer dogs dogs/cats fertilizer ...

  17. The effects of pesticide mixtures on degradation of pendimethalin in soils.

    PubMed

    Swarcewicz, Maria K; Gregorczyk, Andrzej

    2012-05-01

    Most agronomic situations involve a sequence of herbicide, fungicide, and insecticide application. On the other hand, use of pesticidal combinations has become a standard practice in the production of many agricultural crops. One of the most important processes influencing the behavior of a pesticide in the environment is its degradation in soil. It is known that due to several pesticide applications in one vegetation season, the pesticide may be present in mixtures with other pesticides or xenobiotics in soil. This study examines the role which a mixture of chemicals plays in pesticide degradation. The influence of other pesticides on the rate of pendimethalin (PDM) degradation in soil was measured in controlled conditions. Mixtures of PDM with mancozeb or mancozeb and thiamethoxam significantly influenced the degradation of pendimethalin under controlled conditions. The second type of mixtures, with metribuzin or thiamethoxam, did not affect the behavior of pendimethalin in soil. Also, we determined the influence of water content on the rate of pendimethalin degradation alone in two soils and compared it to the rate in three pesticide mixtures. We compared two equations to evaluate the predictors of the rate of herbicide dissipation in soil: the first-order kinetic and the non-linear empirical models. We used the non-linear empirical model assuming that the degradation rate of a herbicide in soil is proportional to the difference of the observed concentration of herbicide in soil at time and concentration of herbicide in the last day of measurement. PMID:21713483

  18. 75 FR 28012 - Pesticides; Draft Guidance for Pesticide Registrants on False or Misleading Pesticide Product...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-19

    ...ENVIRONMENTAL PROTECTION AGENCY [EPA-HQ-OPP-2010-0282; FRL-8824-8] Pesticides; Draft Guidance for Pesticide Registrants on False or Misleading Pesticide Product Brand Names AGENCY: Environmental Protection Agency (EPA)....

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

    Microsoft Academic Search

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

    2002-01-01

    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

  20. Application of microbial hot spots enhances pesticide degradation in soils

    Microsoft Academic Search

    Sabine Grundmann; Roland Fuß; Michael Schmid; Manuela Laschinger; Bernhard Ruth; Rainer Schulin; Jean Charles Munch; Reiner Schroll

    2007-01-01

    Through transfer of an active, isoproturon degrading microbial community, pesticide mineralization could be successfully enhanced in various soils under laboratory and outdoor conditions. The microbes, extracted from a soil having high native ability to mineralize this chemical, were established on expanded clay particles and distributed to various soils in the form of microbial “hot spots”. Both, diffusion controlled isoproturon mass

  1. 75 FR 56105 - Pesticide Products; Registration Applications

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-15

    ...docket that addresses multiple products, please indicate to which registration...as follows to register pesticide products containing currently registered...and address: Sergeant's Pet Care Products, Inc., 2625 South 158th...

  2. Avoid Counterfeit Pesticide Products for Dogs and Cats

    MedlinePLUS

    Avoid Counterfeit Pesticide Products for Dogs and Cats EPA is aware of counterfeit pet pesticides designed to look like legitimately registered pesticide products. The information on this page is intended to ...

  3. SnO 2-based materials for pesticide degradation

    Microsoft Academic Search

    Geoffroy R. P. Malpass; Douglas W. Miwa; Sérgio A. S. Machado; Artur J. Motheo

    2010-01-01

    This study presents the results of the degradation of the pesticide atrazine using electrochemical and photo-assisted electrochemical degradation techniques using SnO2-containing electrode of nominal composition electrodes of composition Ti\\/RuXSn1?XO2 (where X=0.10, 0.15, 0.20, 0.25 and 0.30). The materials were characterized ex situ and in situ in order to correlate the observed atrazine removal rates with electrode morphology\\/composition. The results obtained

  4. Degradation of nitenpyram pesticide in aqueous solution by low-temperature plasma.

    PubMed

    Li, S P; Jiang, Y Y; Cao, X H; Dong, Y W; Dong, M; Xu, J

    2013-01-01

    In order to study the new technique of plasma wastewater treatment, the degradation behaviour ofnitenpyram (NTP) pesticide was investigated in a low-temperature plasma formed during a dielectric barrier discharge process. The reactor was a radial flow sedimentation tank centred around the water inlet. We studied the effect of pesticide concentration and input power of the dielectric barrier discharge, together with the effect of external factors on the degradation of nitenpyram pesticide wastewater such as conductivity and the use of various of catalysts, and the reaction products were analyzed by high-performance liquid chromatography mass spectrometry (HPLC-MS). The results showed that NTP could be effectively removed from aqueous solution by low-temperature plasma. Increasing the input power could improve the efficiency of degradation, conforming to a first-order kinetic model. Use of a suitable catalyst clearly improved the degradation process, as also did low conductivity. The pH of NTP was reduced with discharge time. PMID:24191496

  5. 40 CFR 152.10 - Products that are not pesticides because they are not intended for a pesticidal purpose.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 2010-07-01 false Products that are not pesticides because they are not intended for a pesticidal...ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS PESTICIDE REGISTRATION AND CLASSIFICATION PROCEDURES...

  6. Genome Sequence of Organophosphorus Pesticide-Degrading Bacterium Pseudomonas stutzeri Strain YC-YH1

    PubMed Central

    Shi, Yan-hua; Ren, Lei; Jia, Yang

    2015-01-01

    Pseudomonas stutzeri strain YC-YH1, isolated from pesticide-polluted soil, efficiently degrades organophosphorus pesticides (OPPs) such as chlorpyrifos, parathion-methyl, triazophos, and parathion. Here, we report the genome sequence (4.83 Mb) of P. stutzeri YC-YH1 to facilitate further investigation of the OPP-degrading mechanism. PMID:25814604

  7. GC\\/MS studies on revealing products and reaction mechanism of photodegradation of pesticides

    Microsoft Academic Search

    A. Kiss; S. Rapi; Cs. Csutorás

    2007-01-01

    The photolytic degradation of frequently applied s-triazine type pesticides was investigated. A special, immersible UV-light source was applied in order to carry out photodegradation. The degradation processes were followed by TLC, GC and GC\\/MS techniques. Following the irradiation of the sample, the degradation products were isolated by SPE column chromatography. EI mass spectrometry was used to identify the degradation species.All

  8. Partial degradation of five pesticides and an industrial pollutant by ozonation in a pilot-plant scale reactor

    Microsoft Academic Search

    M. I. Maldonado; S. Malato; L. A. Pérez-Estrada; W. Gernjak; I. Oller; Xavier Doménech; José Peral

    2006-01-01

    Aqueous solutions of a mixture of several pesticides (alachlor, atrazine, chlorfenvinphos, diuron and isoproturon), considered PS (priority substances) by the European Commission, and an intermediate product of the pharmaceutical industry (?-methylphenylglycine, MPG) chosen as a model industrial pollutant, have been degraded at pilot-plant scale using ozonation. This study is part of a large research project [CADOX Project, A Coupled Advanced

  9. Compound specific isotope analysis to investigate pesticide degradation in lysimeter experiments at field conditions

    NASA Astrophysics Data System (ADS)

    Ryabenko, Evgenia; Elsner, Martin; Bakkour, Rani; Hofstetter, Thomas; Torrento, Clara; Hunkeler, Daniel

    2015-04-01

    The frequent detection of organic micropollutants such as pesticides, consumer care products or pharmaceuticals in water is an increasing concern for human and ecosystem health. Degradation analysis of these compounds can be challenging in complex systems due to the fact that metabolites are not always found and mass balances frequently cannot be closed. Many abiotic and biotic degradation pathways cause, however, distinct isotope fractionation, where light isotopes are transferred preferentially from the reactant to the product pool (normal isotope fractionation). Compound-specific isotope analysis (CSIA) of multiple elements is a particularly powerful method to evaluate organic micropollutant transformation, because it can even give pathway-specific isotope fractionation (1,2). Available CSIA field studies, however, have focused almost exclusively on volatile petroleum and chlorinated hydrocarbons, which are present in high concentrations in the environment and can be extracted easily from water for GC-IRMS analysis. In the case of micropollutants, such as pesticides, CSIA in more challenging since it needs to be conducted at lower concentrations and requires pre-concentration, purification and high chromatographic performance (3). In this study we used lysimeters experiments to analyze transformation of atrazine, acetochlor, metolachlor and chloridazone by studying associated isotope fractionation. The project combines a) analytical method development for CSIA, b) identification of pathways of micropollutant degradation and c) quantification of transformation processes under field condition. The pesticides were applied both, at the soil surface and below the top soil under field-relevant concentrations in May 2014. After typical irrigation of the lysimeters, seepage water was collected in 50L bottles and stored for further SPE and CSIA. Here we present the very first result of a) analytical method development, b) improvement of SPE methods for complex pesticide mixtures and c) transformation of pesticides in lysimeters during the year 2014. 1 Elsner, M. Stable isotope fractionation to investigate natural transformation mechanisms of organic contaminants: principles, prospects and limitations. J. Environ. Monit. 12, 2005-2031 (2010). 2 Hofstetter, T. B. & Berg, M. Assessing transformation processes of organic contaminants by compound-specific stable isotope analysis. TrAC Trends in Analytical Chemistry 30, 618-627 (2011). 3 Elsner, M. et al. Current challenges in compound-specific stable isotope analysis of environmental organic contaminants. Anal. Bioanal. Chem. 403, 2471-2491, doi:10.1007/s00216-011-5683-y (2012).

  10. ORGANOPHOSPHORUS PESTICIDE DEGRADATION PATHWAYS DURING DRINKING WATER TREATMENT

    EPA Science Inventory

    The objective of this work was to investigate organophosphorus (OP) pesticide transformation pathways as a class in the presence of aqueous chlorine. Seven priority OP pesticides were examined for their reactivity with aqueous chlorine: chlorpyrifos (CP), parathion (PA), diazino...

  11. 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...

  12. 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...

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

    PubMed

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

    2006-12-01

    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

  14. 75 FR 74713 - Product Cancellation Order for Certain Pesticide Registrations; Correction

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-01

    ...cancellation of multiple pesticide products. This document is being issued...cancellation of Sergeant's Pet Care Products' pesticide product, EPA Reg...cancellation of Sergeant's Pet Care Products' pesticide product, EPA...

  15. In-package nonthermal plasma degradation of pesticides on fresh produce.

    PubMed

    Misra, N N; Pankaj, S K; Walsh, Tony; O'Regan, Finbarr; Bourke, Paula; Cullen, P J

    2014-04-30

    In-package nonthermal plasma (NTP) technology is a novel technology for the decontamination of foods and biological materials. This study presents the first report on the potential of the technology for the degradation of pesticide residues on fresh produce. A cocktail of pesticides, namely azoxystrobin, cyprodinil, fludioxonil and pyriproxyfen was tested on strawberries. The concentrations of these pesticides were monitored in priori and post-plasma treatment using GC-MS/MS. An applied voltage and time dependent degradation of the pesticides was observed for treatment voltages of 60, 70 and 80 kV and treatment durations ranging from 1 to 5 min, followed by 24h in-pack storage. The electrical characterisation revealed the operation of the discharge in a stable filamentary regime. The discharge was found to generate reactive oxygen and excited nitrogen species as observed by optical emission spectroscopy. PMID:24598029

  16. 9 CFR 318.16 - Pesticide chemicals and other residues in products.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...2010-01-01 2010-01-01 false Pesticide chemicals and other residues in products...OF PRODUCTS General § 318.16 Pesticide chemicals and other residues in products...Nonmeat ingredients. Residues of pesticide chemicals, food additives...

  17. Assessment of the PD-TOFMS Technique for Pesticide Adsorption and Degradation on `as-received' Treated Soil

    E-print Network

    Paris-Sud XI, Université de

    1 Assessment of the PD-TOFMS Technique for Pesticide Adsorption and Degradation on `as The assessment of the PD-TOFMS technique as a tool for direct characterization of pesticides adsorbed pesticides, namely norflurazon, malathion and oxyfluorfen, as well as deposits of these solutions onto

  18. 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...

  19. Effects of halving pesticide use on wheat production

    PubMed Central

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

    2014-01-01

    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. PMID:24651597

  20. Photocatalytic degradation of pesticide residues with RE 3+ -doped nano-TiO 2

    Microsoft Academic Search

    Rui ZENG; Jingguo WANG; Jianyu CUI; Lin HU; Kangguo MU

    2010-01-01

    The photocatalytic degradation effects of carbofuran solution under concentration of 0.2, 0.4, 0.8 g\\/L Re3+-doped nano-TiO2 were studied. The highest degradation rate of 54.89% was obtained after 4 h degradation when the concentration of nano-TiO2 was 0.4 g\\/L. Then field trials of photocatalytic degradation with suspension nano-TiO2 were conducted. The photocatalytic degradation effect of organic phosphorus and carbamate pesticides in

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

    NASA Astrophysics Data System (ADS)

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

    2013-04-01

    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.

  2. 78 FR 53139 - Pesticide Product Registration; Receipt of Application for New Uses

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-28

    ...pesticide products containing the insecticide flonicamid, pursuant to the provisions of the Federal Insecticide, Fungicide, and Rodenticide Act...pesticide products containing the insecticide, flonicamid...

  3. Heterogeneous photocatalysed degradation of two selected pesticide derivatives, triclopyr and daminozid in aqueous suspensions of titanium dioxide.

    PubMed

    Qamar, M; Muneer, M; Bahnemann, D

    2006-07-01

    Heterogeneous photocatalysed degradation of two selected pesticide derivatives, triclopyr (1) and daminozid (2), has been investigated in aqueous suspensions of titanium dioxide by monitoring the change in substrate concentration employing the UV Spectroscopic analysis technique and depletion of Total Organic Carbon (TOC) content as a function of irradiation time. The degradation kinetics were studied under different conditions such as reaction pH, substrate and catalyst concentration, different types of TiO2 and in the presence of electron acceptors such as hydrogen peroxide (H2O2), potassium bromate (KBrO3) and ammonium persulphate (NH4)2S2O8 in addition to molecular oxygen. The degradation rates were found to be strongly influenced by all the above parameters. The photocatalyst Degussa P25 was found to be more efficient as compared with other photocatalysts. The pesticide derivative triclopyr (1) was found to degrade faster as compared to daminozid (2). An attempt was also made to identify the intermediate products formed during the photooxidation process using GC/MS analysis. Probable pathways for the formation of products have been proposed. PMID:16359776

  4. Fine scale spatial variability of microbial pesticide degradation in soil: scales, controlling factors, and implications

    PubMed Central

    Dechesne, Arnaud; Badawi, Nora; Aamand, Jens; Smets, Barth F.

    2014-01-01

    Pesticide biodegradation is a soil microbial function of critical importance for modern agriculture and its environmental impact. While it was once assumed that this activity was homogeneously distributed at the field scale, mounting evidence indicates that this is rarely the case. Here, we critically examine the literature on spatial variability of pesticide biodegradation in agricultural soil. We discuss the motivations, methods, and main findings of the primary literature. We found significant diversity in the approaches used to describe and quantify spatial heterogeneity, which complicates inter-studies comparisons. However, it is clear that the presence and activity of pesticide degraders is often highly spatially variable with coefficients of variation often exceeding 50% and frequently displays non-random spatial patterns. A few controlling factors have tentatively been identified across pesticide classes: they include some soil characteristics (pH) and some agricultural management practices (pesticide application, tillage), while other potential controlling factors have more conflicting effects depending on the site or the pesticide. Evidence demonstrating the importance of spatial heterogeneity on the fate of pesticides in soil has been difficult to obtain but modeling and experimental systems that do not include soil's full complexity reveal that this heterogeneity must be considered to improve prediction of pesticide biodegradation rates or of leaching risks. Overall, studying the spatial heterogeneity of pesticide biodegradation is a relatively new field at the interface of agronomy, microbial ecology, and geosciences and a wealth of novel data is being collected from these different disciplinary perspectives. We make suggestions on possible avenues to take full advantage of these investigations for a better understanding and prediction of the fate of pesticides in soil. PMID:25538691

  5. Dependence of pesticide degradation on sorption: nonequilibrium model and application to soil reactors

    NASA Astrophysics Data System (ADS)

    Guo, Lei; Jury, William A.; Wagenet, Robert J.; Flury, Markus

    2000-04-01

    The effect of sorption on degradation of the pesticide 2,4-dichlorophenoxyacetic acid (2,4-D) was studied in a soil amended with various amounts of activated carbon (AC). The relationship between sorption and decay of 2,4-D was analyzed using analytical solutions for equilibrium sorption and to a two-site nonequilibrium adsorption model coupled with two first-order degradation terms for the dissolved and sorbed pesticide, respectively. The sorption parameters in the latter model were determined based on data obtained from batch sorption experiments, while those for degradation were obtained from incubation experiments. The adsorption coefficients, ranging from 0.811 to >315 ml g -1, increased at higher AC, and were negatively related to degradation as measured by the first-order rate constant, implying that degradation is faster from the liquid phase than from the sorbed phase. A nonlinear fit of the decay curves to the nonequilibrium model revealed that degradation rate constants were 0.157 and 0.00243 day -1 for the liquid and sorbed phases, respectively, differing by a factor of 65. Similar results were also obtained using the equilibrium model. A parameter sensitivity analysis of the nonequilibrium model indicates that nonequilibrium sorption will initially favor degradation; however, over the long term, will decrease degradation when desorption kinetics becomes the limiting factor in the degradation process. In the presence of a lag phase that allows appreciable amounts of chemical to diffuse into kinetic sorption sites, nonequilibrium sorption will only impede degradation.

  6. 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...

  7. 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 ...

  8. Integration of Solar Photocatalysis and Membrane Bioreactor for Pesticides Degradation

    Microsoft Academic Search

    J. L. Casas López; A. Cabrera Reina; E. Ortega Gómez; M. M. Ballesteros Martín; S. Malato Rodríguez; J. A. Sánchez Pérez

    2010-01-01

    Wastewater containing recalcitrant contaminants as pesticides can be treated by a coupled system which consists of a solar photo-Fenton pretreatment followed by a biological oxidation process. Membrane bioreactor technology (MBR) is particularly suitable for advanced biological treatment of wastewater containing biorecalcitrant compounds and shows a variety of advantages that make it a good alternative to be coupled with photo-Fenton, especially

  9. Degradation of pesticides chlorpyrifos, cypermethrin and chlorothalonil in aqueous solution by TiO2 photocatalysis.

    PubMed

    Affam, Augustine Chioma; Chaudhuri, Malay

    2013-11-30

    Degradation of pesticides chlorpyrifos, cypermethrin and chlorothalonil in aqueous solution by TiO2 photocatalysis under UVA (365 nm) irradiation was examined. Enhancement of degradation and improvement in biodegradability index (BOD5/COD ratio) by H2O2 addition were also evaluated. UVA irradiation per se produced insignificant degradation of the pesticides. In UV/TiO2 photocatalysis (TiO2 1.5 g L(-1), pH 6 and 300 min irradiation), COD and TOC removal were 25.95 and 8.45%, respectively. In UV/TiO2/H2O2 photocatalysis (TiO2 1.5 g L(-1), H2O2 100 mg L(-1), pH 6 and 300 min irradiation), COD and TOC removal were 53.62 and 21.54%, respectively and biodegradability index improved to 0.26. Ammonia-nitrogen (NH3-N) decreased from 22 to 7.8 mg L(-1) and nitrate-nitrogen (NO3(-)-N) increased from 0.7 to 13.8 mg L(-1) in 300 min, indicating mineralization. Photocatalytic degradation followed pseudo-first order kinetics with rate constant (k) of 0.0025 and 0.0008 min(-1) for COD and TOC removal, respectively. FTIR spectra indicated degradation of the organic bonds of the pesticides. UV/TiO2/H2O2 photocatalysis is effective in degradation of pesticides chlorpyrifos, cypermethrin and chlorothalonil in aqueous solution. UV/TiO2/H2O2 photocatalysis may be applied as pretreatment of a chlorpyrifos, cypermethrin and chlorothalonil pesticide wastewater at pH 6, for biological treatment. PMID:24076516

  10. Effect of different soil textures on leaching potential and degradation of pesticides in biobeds.

    PubMed

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

    2004-09-01

    Biobeds can be used to intercept pesticide-contaminated runoff from the mixing/washdown area, creating optimum conditions for sorption and biodegradation such that the amount of pesticide reaching adjacent water bodies is significantly reduced. The biobed is built on the farm using locally available materials, which include, straw, compost, and topsoil. The topsoil acts as the inoculum for the system and is likely to vary in terms of its physical, chemical, and microbiological characteristics from one farm to another. This study therefore investigated the effects of using different soil types on the degradation and leaching potential from biobeds. Three contrasting topsoils were investigated. Leaching studies were performed using isoproturon, dimethoate, and mecoprop-P, which were applied at simulated disposal rates to 1.5 m deep biobeds. Annual average concentrations were similar for each soil type with leaching losses of even the most mobile (Koc = 12-25) pesticide <1.64% of the applied dose. Greater than 98% of the retained pesticides were degraded in all matrices. Degradation studies investigated the persistence of individual pesticides and pesticide mixtures in the different matrices. DT50 values for isoproturon, chlorothalonil, mecoprop-P, and metsulfuron-methyl applied at 4 times the maximum approved rate were similar across the biomix types and were all less than or equal to reported DT50 values for soil treated at approved rates. When applied as a mixture, DT50 values in each biomix increased, indicating that interactions between pesticides are possible. However, DT90 values of <167 days were obtained in all circumstances, indicating a negligible risk of accumulation. Studies therefore indicate that substrate will have little impact on biobed performance so it should be possible to use local soils in the construction process. PMID:15373405

  11. Pesticides.

    ERIC Educational Resources Information Center

    Sherma, Joseph

    1989-01-01

    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)

  12. Pesticides removal in the process of drinking water production.

    PubMed

    Ormad, M P; Miguel, N; Claver, A; Matesanz, J M; Ovelleiro, J L

    2008-03-01

    The aim of this research work was to study the effectiveness of the treatments commonly used in drinking water plants in Spain to degrade 44 pesticides systematically detected in the Ebro River Basin. The pesticides studied are: alachlor, aldrin, ametryn, atrazine, chlorfenvinfos, chlorpyrifos, pp'-DDD, op'-DDE, op'-DDT, pp'-DDT, desethylatrazine, 3,4-dichloroaniline, 4,4'-dichlorobenzophenone, dicofol, dieldrin, dimethoate, diuron, alpha-endosulphan, endosulphan-sulphate, endrin, alpha-HCH, beta-HCH, gamma-HCH, delta-HCH, heptachlor, heptachlor epoxide A, heptachlor epoxide B, hexachlorobenzene, isodrin, 4-isopropylaniline, isoproturon, metholachlor, methoxychlor, molinate, parathion methyl, parathion ethyl, prometon, prometryn, propazine, simazine, terbuthylazine, terbutryn, tetradifon and trifluralin. The techniques applied are: preoxidation by chlorine or ozone, chemical precipitation with aluminium sulphate and activated carbon adsorption. Oxidation by chlorine removes 60% of the studied pesticides, although combining this technique with a coagulation-flocculation-decantation process is more effective. The disadvantage of this treatment is the formation of trihalomethanes. Oxidation by ozone removes 70% of the studied pesticides. Although combination with a subsequent coagulation-flocculation-decantation process does not improve the efficiency of the process, combination with an activated-carbon absorption process gives rise to 90% removal of the studied pesticides. This technique was found to be the most efficient among the techniques studied for degrading the majority of the studied pesticides. PMID:18023468

  13. Heterogeneous Photocatalytic Degradation of Selected Organophosphate Pesticides: A Review

    Microsoft Academic Search

    Dhiraj Sud; Paramjeet Kaur

    2011-01-01

    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

  14. 40 CFR 152.15 - Pesticide products required to be registered.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 23 2010-07-01 2010-07-01 false Pesticide products required to be registered. 152.15...ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS PESTICIDE REGISTRATION AND CLASSIFICATION PROCEDURES...

  15. Degradation of chlorotriazine pesticides by sulfate radicals and the influence of organic matter.

    PubMed

    Lutze, Holger V; Bircher, Stephanie; Rapp, Insa; Kerlin, Nils; Bakkour, Rani; Geisler, Melanie; von Sonntag, Clemens; Schmidt, Torsten C

    2015-02-01

    Atrazine, propazine, and terbuthylazine are chlorotriazine herbicides that have been frequently used in agriculture and thus are potential drinking water contaminants. Hydroxyl radicals produced by advanced oxidation processes can degrade these persistent compounds. These herbicides are also very reactive with sulfate radicals (2.2-3.5 × 10(9) M(-1) s(-1)). However, the dealkylated products of chlorotriazine pesticides are less reactive toward sulfate radicals (e.g., desethyl-desisopropyl-atrazine (DEDIA; 1.5 × 10(8) M(-1) s(-1))). The high reactivity of the herbicides is largely due to the ethyl or isopropyl group. For example, desisopropyl-atrazine (DIA) reacts quickly (k = 2 × 10(9) M(-1) s(-1)), whereas desethyl-atrazine (DEA) reacts more slowly (k = 9.6 × 10(8) M(-1) s(-1)). The tert-butyl group does not have a strong effect on reaction rate, as shown by the similar second order reaction rates between desethyl-terbuthylazine (DET; k = 3.6 × 10(8) M(-1) s(-1)) and DEDIA. Sulfate radicals degrade a significant proportion of atrazine (63%) via dealkylation, in which deethylation significantly dominates over deisopropylation (10:1). Sulfate and hydroxyl radicals react at an equally fast rate with atrazine (k (hydroxyl radical + atrazine) = 3 × 10(9) M(-1) s(-1)). However, sulfate and hydroxyl radicals differ considerably in their reaction rates with humic acids (k (sulfate radical + humic acids) = 6.8 × 10(3) L mgC(-1) s(-1) (mgC = mg carbon); k (hydroxyl radical + humic acids) = 1.4 × 10(4) L mgC(-1) s(-1)). Thus, in the presence of humic acids, atrazine is degraded more efficiently by sulfate radicals than by hydroxyl radicals. PMID:25347797

  16. Products from Lignocellulosic Materials via Degradation Processes

    Microsoft Academic Search

    A. Demirbas

    2007-01-01

    Products from lignicellulosic materials by degradation processes are reviewed based on the results of some investigations. Biomass provides a potential source of added value chemicals, such as reducing sugars, furfural, ethanol and other products by using biochemical or chemical and thermochemical. The initial degradation reactions include depolymerization, hydrolysis, oxidation, dehydration, and decarboxylation. The gas phase of pyrolitic degradation products contain

  17. Ozone-driven photocatalyzed degradation and mineralization of pesticide, Triclopyr by Au/TiO2.

    PubMed

    Maddila, Suresh; Rana, Surjakanta; Pagadala, Ramakanth; Maddila, Surya N; Vasam, Chandrasekhar; Jonnalagadda, Sreekantha B

    2015-08-01

    Triclopyr is a widely used pesticide which is non-biodegradable and enters aquatic systems. The ozone facilitated photocatalyzed degradation and mineralization of Triclopyr using Au-loaded titania as heterogeneous catalyst is reported. The oxidative degradation activity of the hazardous pesticide was investigated at pH 7.8 under varied reaction conditions, including in presence and absence of ozone, titania alone, in presence and absence of light and with different loadings of Au on support. Photocatalysis with 2% Au/TiO2 in the presence of ozone yielded 100% degradation of Triclopyr in 2 h. The extent of degradation of pesticide and its mineralization were confirmed by GC-MS. For 10 mg/L of Triclopyr, 0.1 g/L of catalyst was found to be the optimum for mineralization. Results show that photocatalyzed ozonation with Au/TiO2 as catalyst is a very effective for its removal. No leaching of Au was observed in triplicate runs. Catalyst was fully recoverable and reusable with no loss of activity. PMID:26065517

  18. Degradation of organophosphorus pesticide parathion methyl on nanostructured titania-iron mixed oxides

    NASA Astrophysics Data System (ADS)

    Henych, Ji?í; Štengl, Václav; Slušná, Michaela; Matys Grygar, Tomáš; Janoš, Pavel; Kurá?, Pavel; Štastný, Martin

    2015-07-01

    Titania-iron mixed oxides with various Ti:Fe ratio were prepared by homogeneous hydrolysis of aqueous solutions of titanium(IV) oxysulphate and iron(III) sulphate with urea as a precipitating agent. The synthesized samples were characterized by X-ray diffraction, Raman and infrared spectroscopy, scanning and transmission electron microscopy, XRF analysis, specific surface area (BET) and porosity determination (BJH). These oxides were used for degradation of organophosporus pesticide parathion methyl. The highest degradation efficiency approaching <70% was found for the samples with Ti:Fe ratio 0.25:1 and 1:0.25. Contrary, parathion methyl was not degraded on the surfaces of pure oxides. In general, the highest degradation rate exhibited samples consisted of the iron or titanium oxide containing a moderate amount of the admixture. However, distinct correlations between the degradation rate and the sorbent composition were not identified.

  19. Concentrations of pesticides and pesticide degradates in the Croton River Watershed in southeastern New York, July-September 2000

    USGS Publications Warehouse

    Phillips, Patrick J.; Bode, Robert W.

    2002-01-01

    Thirty-seven pesticides and (or) pesticide degradates were detected in baseflow samples collected from 47 stream sites in the Croton River Watershed (374 square miles) in southeastern New York in the summer of 2000. The Croton Reservoir provides about 10 percent of New York City's water supply. Maximum concentrations of most pesticides detected did not exceed 0.1 ?g/L (micrograms per liter). This study, by the U.S. Geological Survey in cooperation with the New York State Department of Environmental Conservation, was conducted from July through September 2000 and entailed analysis of the samples for more than 150 pesticides and their degradates. Nine compounds were detected at a concentration greater than 0.10 ?g/L; three of these were insecticides (diazinon, carbaryl, and imidacloprid), one was a fungicide (mycobutanil), and five were herbicides (simazine, 2,4-D, diuron, hexazinone, and 2,4-D methyl esther). Only two of these compounds (simazine and 2,4-D) were detected at a concentration exceeding 1 ?g/L; the simazine concentration exceeded the New York State surface-water standard of 0.5 ?g/L. Two insecticides (diazinon and azinphos-methyl) exceeded aquatic-life-protection standard in one sample each. Concentrations of three insecticides (chlorpyrifos, carbaryl, and malathion) were more than 50 percent of the aquatic-life-protection standards in one sample each. Total concentrations of insecticides and herbicides (the sum of the concentrations, whereby all concentrations below the detection limit were set to zero), and the concentrations of the herbicide prometon and the insecticide diazinon, were highest in samples from watersheds with population densities greater than 510 per square mile (21 sites); therefore, the presence of these compounds is attributable to urban, residential, and other developed land uses. The data obtained in this study are useful for making general comparisons among watersheds with differing land uses, but the concentrations represent baseflow conditions and, thus, are probably lower than the annual maximum concentrations in these streams. A July baseflow sample had total insecticide and fungicide concentrations of less than 0.03 ?g/L, whereas a stormflow sample collected at the same site 2 weeks later had a corresponding concentration greater than 0.10 ?g/L. Total herbicide concentrations for the July baseflow and stormflow samples were around 0.03 ?g/L, but that for a stormflow sample collected at the same site 2 months later was greater than 20 ?g/L.

  20. Pesticides

    MedlinePLUS

    ... people are exposed to low levels of pesticide residues through their diets. Scientists do not yet have ... understanding of the health effects of these pesticide residues. Results from the Agricultural Health Study, an ongoing ...

  1. Investigation of the photocatalytic degradation of organochlorine pesticides on a nano-TiO 2 coated film

    Microsoft Academic Search

    Binbin Yu; Jingbin Zeng; Lifen Gong; Maosheng Zhang; Limei Zhang; Xi Chen

    2007-01-01

    The photocatalytic degradation of organochlorine pesticides including ?-, ?-, ?-, ?-hexachlorobenzene (BHC), dicofol and cypermethrin were carried out on a nano-TiO2 coated films under UV irradiation in the air. The photocatalytic conditions, including the amount of TiO2, irradiation time and the intensity of light were optimized. The pesticides were most effectively degraded under the condition of 2.24mg\\/cm2 on TiO2 film

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

    Microsoft Academic Search

    Keisuke Ikehata; Mohamed Gamal El-Din

    2005-01-01

    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

  3. Titanium dioxide photoinduced degradation of some pesticide/fungicide precursors.

    PubMed

    Kuehr, Ivana; Núñez, Oswaldo

    2007-05-01

    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

  4. 40 CFR 158.2030 - Biochemical pesticides product chemistry data requirements table.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...Use patterns . Product chemistry data are required for all...biochemical pesticides product chemistry. The test notes are shown...Biochemical Pesticides Product Chemistry Data Requirements Guideline...method R MP EP 7 Physical and Chemical...

  5. 40 CFR 158.2030 - Biochemical pesticides product chemistry data requirements table.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...Use patterns . Product chemistry data are required for all...biochemical pesticides product chemistry. The test notes are shown...Biochemical Pesticides Product Chemistry Data Requirements Guideline...method R MP EP 7 Physical and Chemical...

  6. 40 CFR 158.2030 - Biochemical pesticides product chemistry data requirements table.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...Use patterns . Product chemistry data are required for all...biochemical pesticides product chemistry. The test notes are shown...Biochemical Pesticides Product Chemistry Data Requirements Guideline...method R MP EP 7 Physical and Chemical...

  7. 40 CFR 158.2081 - Experimental use permit biochemical pesticides product chemistry data requirements table.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...Use patterns . Product chemistry data are required for all...biochemical pesticides product chemistry. The test notes are shown...Biochemical Pesticides Product Chemistry Data Requirements Guideline...method R MP EP 7 Physical and Chemical...

  8. 40 CFR 158.2030 - Biochemical pesticides product chemistry data requirements table.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...Use patterns. Product chemistry data are required for all...biochemical pesticides product chemistry. The test notes are shown...Biochemical Pesticides Product Chemistry Data Requirements Guideline...method R MP EP 7 Physical and Chemical...

  9. 40 CFR 158.2081 - Experimental use permit biochemical pesticides product chemistry data requirements table.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...Use patterns . Product chemistry data are required for all...biochemical pesticides product chemistry. The test notes are shown...Biochemical Pesticides Product Chemistry Data Requirements Guideline...method R MP EP 7 Physical and Chemical...

  10. 40 CFR 158.2030 - Biochemical pesticides product chemistry data requirements table.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...Use patterns . Product chemistry data are required for all...biochemical pesticides product chemistry. The test notes are shown...Biochemical Pesticides Product Chemistry Data Requirements Guideline...method R MP EP 7 Physical and Chemical...

  11. 40 CFR 158.2081 - Experimental use permit biochemical pesticides product chemistry data requirements table.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...Use patterns. Product chemistry data are required for all...biochemical pesticides product chemistry. The test notes are shown...Biochemical Pesticides Product Chemistry Data Requirements Guideline...method R MP EP 7 Physical and Chemical...

  12. 40 CFR 158.2081 - Experimental use permit biochemical pesticides product chemistry data requirements table.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...Use patterns . Product chemistry data are required for all...biochemical pesticides product chemistry. The test notes are shown...Biochemical Pesticides Product Chemistry Data Requirements Guideline...method R MP EP 7 Physical and Chemical...

  13. 40 CFR 158.2081 - Experimental use permit biochemical pesticides product chemistry data requirements table.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...Use patterns . Product chemistry data are required for all...biochemical pesticides product chemistry. The test notes are shown...Biochemical Pesticides Product Chemistry Data Requirements Guideline...method R MP EP 7 Physical and Chemical...

  14. Catalytic strategy for efficient degradation of nitroaromatic pesticides by using gold nanoflower.

    PubMed

    Mao, Kang; Chen, Yinran; Wu, Zitong; Zhou, Xiaodong; Shen, Aiguo; Hu, Jiming

    2014-11-01

    In this contribution, we report a new type of Au nanoflower-based nitroaromatic pesticide degradation platform that is fast, efficient, and simple. We found a straightforward, economically viable, and "green" approach for the synthesis and stabilization of relatively monodisperse Au nanoflowers by using nontoxic chemical of hydroxylamine (NH2OH) without stabilizer and the adjustment of the pH environment. This experiment shows that these Au nanoflowers function as effective catalyst for the reduction of pendimethalin in the presence of NaBH4 (otherwise unfeasible if NaBH4 is the only agent employed), which was reflected by the UV/vis spectra of the catalytic reaction kinetics. Importantly, the novel degradation platform could be put in use in two different practical soil samples with satisfactory results under laboratory conditions. To demonstrate the feasibility and universality of our design, two other nitroaromatic pesticides, trifluralin, and p-nitrophenol, were selected and were successfully degraded using this degradation platform. PMID:25329810

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

    PubMed

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

    2006-12-01

    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

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

    SciTech Connect

    Not Available

    1992-05-01

    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.)

  17. Input dynamics of pesticide transformation products into surface water

    NASA Astrophysics Data System (ADS)

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

    2010-05-01

    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

  18. Structure-Guided Engineering of Molinate Hydrolase for the Degradation of Thiocarbamate Pesticides

    PubMed Central

    Paiva, Ana M.; Ferreira-da-Silva, Frederico; Matias, Pedro M.; Nunes, Olga C.; Gales, Luís

    2015-01-01

    Molinate is a recalcitrant thiocarbamate used to control grass weeds in rice fields. The recently described molinate hydrolase, from Gulosibacter molinativorax ON4T, plays a key role in the only known molinate degradation pathway ending in the formation of innocuous compounds. Here we report the crystal structure of recombinant molinate hydrolase at 2.27 Å. The structure reveals a homotetramer with a single mononuclear metal-dependent active site per monomer. The active site architecture shows similarities with other amidohydrolases and enables us to propose a general acid-base catalysis mechanism for molinate hydrolysis. Molinate hydrolase is unable to degrade bulkier thiocarbamate pesticides such as thiobencarb which is used mostly in rice crops. Using a structural-based approach, we were able to generate a mutant (Arg187Ala) that efficiently degrades thiobencarb. The engineered enzyme is suitable for the development of a broader thiocarbamate bioremediation system. PMID:25905461

  19. Planktonic versus biofilm catabolic communities: importance of the biofilm for species selection and pesticide degradation.

    PubMed

    Verhagen, Pieter; De Gelder, Leen; Hoefman, Sven; De Vos, Paul; Boon, Nico

    2011-07-01

    Chloropropham-degrading cultures were obtained from sludge and soil samples by using two different enrichment techniques: (i) planktonic enrichments in shaken liquid medium and (ii) biofilm enrichments on two types of solid matrixes (plastic chips and gravel). Denaturing gradient gel electrophoresis fingerprinting showed that planktonic and biofilm cultures had a different community composition depending on the presence and type of added solid matrix during enrichment. This was reflected in the unique chloropropham-degrading species that could be isolated from the different cultures. Planktonic and biofilm cultures also differed in chloropropham-degrading activity. With biofilm cultures, slower chloropropham removal was observed, but with less build-up of the toxic intermediate 3-chloroaniline. Disruption of the biofilm architecture resulted in degradation characteristics shifting toward those of the free suspensions, indicating the importance of a well-established biofilm structure for good performance. These results show that biofilm-mediated enrichment techniques can be used to select for pollutant-degrading microorganisms that like to proliferate in a biofilm and that cannot be isolated using conventional shaken-liquid procedures. Furthermore, the influence of the biofilm architecture on the pesticide degradation characteristics suggests that for bioaugmentation the use of biofilm catabolic communities might be a proficient alternative to using planktonic freely suspended cultures. PMID:21602394

  20. 78 FR 4073 - Labeling of Pesticide Products and Devices for Export; Clarification of Requirements

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-18

    ...FRL-9360-8] RIN 2070-AJ53 Labeling of Pesticide Products and Devices for Export; Clarification...revising the regulations on the labeling of pesticide products and devices intended solely...that people who transfer unregistered pesticide products between registered...

  1. Original article Pesticide residues in bee products collected from

    E-print Network

    Paris-Sud XI, Université de

    Original article Pesticide residues in bee products collected from cherry trees protected during, iprodione and methyl tiophanate) residues were determined in honey, pollen and bee bread from a plantation up to 0.1 mg·kg-1 and pollen with up to 0.25 mg·kg-1,and the most contaminated was bee bread with up

  2. Organochlorine pesticide residues in dairy products in Jordan

    Microsoft Academic Search

    Nida’ M. Salem; Rafat Ahmad; Hussein Estaitieh

    2009-01-01

    The use of aldrin, dieldrin, endrin, heptachlor and hexachlorobenzene (HCB) has been banned in Jordan officially in 1981, and of dichlorodiphenyltrichloroethane (DDT) in 1995. However, residues of such compounds can still be found in the environment and in foodstuffs. Dairy products are an important exposure route for organochlorine pesticides (OCPs) to humans. For this reason, the presence of OCP residues

  3. Pesticides

    MedlinePLUS

    ... are applied during farming and how much pesticide residue can remain in foods sold in stores. Exposure ... at work should be careful about cleaning any residue from their skin, and removing their clothes and ...

  4. Exposure Assessment for Pesticide Intake from Multiple Food Products : A Bayesian

    E-print Network

    Theobald, Chris

    Exposure Assessment for Pesticide Intake from Multiple Food Products : A Bayesian Latent-Variable Approach May 1, 2008 1 #12;1 Abstract Pesticide risk assessment for food products involves combining information from consumption and concentration data sets to estimate a distribution for the pesticide intake

  5. Pesticide Consumer Alerts

    MedlinePLUS

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

  6. Degradation of atrazine, metolachlor, and pendimethalin in pesticide?contaminated soils: Effects of aged residues on soil respiration and plant survival

    Microsoft Academic Search

    Jennifer C. Anhalt; Ellen L. Arthur; Todd A. Anderson; Joel R. Coats

    2000-01-01

    This study was conducted to determine the effects of pesticide mixtures on degradation patterns of parent compounds as well as effects on soil microbial respiration. Bioavailability of residues to sensitive plant species was also determined. Soil for this study was obtained from a pesticide?contaminated area within an agrochemical dealer site. Degradation patterns were not affected by the presence or absence

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

    PubMed

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

    2013-12-01

    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

  8. Pesticides and pesticide degradates in the East Fork Little Miami River and William H. Harsha Lake, southwestern Ohio, 1999-2000

    USGS Publications Warehouse

    Funk, Jason M.; Reutter, David C.; Rowe, Gary L.

    2003-01-01

    In 1999 and 2000, the U.S. Geological Survey National Water-Quality Assessment (NAWQA) Program conducted a national pilot study of pesticides and degradates in drinking-water supplies, in cooperation with the U.S. Environmental Protection Agency (USEPA). William H. Harsha Lake, which provides drinking water for several thousand people in southwestern Ohio, was selected as one of the drinking-water supplies for this study. East Fork Little Miami River is the main source of water to Harsha Lake and drains a predominantly agricultural basin. Samples were collected from the East Fork Little Miami River upstream from Harsha Lake, at the drinking-water intake at Harsha Lake, at the outfall just below Harsha Lake, and from treated water at the Bob McEwen Treatment Plant. These samples were analyzed using standardized methods developed for the NAWQA Program. In all, 42 pesticide compounds (24 herbicides, 4 insecticides, 1 fungicide, and 13 degradates) were detected at least once in samples collected during this study. No compound in the treated water samples exceeded any drinking-water standard, although atrazine concentrations in untreated water exceeded the USEPA Maximum Contaminant Level (MCL) for drinking water (3 ?g/L) on four occasions. At least eight compounds were detected with greater than 60 percent frequency at each sampling location. Herbicides, such as atrazine, alachlor, acetochlor, cyanazine, metolachlor, and simazine, were detected most frequently. Rainfall affected the pesticide concentrations in surface waters of the East Fork Little Miami River Basin. Drought conditions from May through November 1999 led to lower streamflow and pesticide concentrations throughout southwestern Ohio. More normal climate conditions during 2000 resulted in higher streamflows and seasonally higher concentrations in the East Fork Little Miami River and Harsha Lake for some pesticides Comparison of pesticide concentrations in untreated lake water and treated drinking water supplied by the Bob McEwen Treatment Plant suggests that treatment processes employed by the plant (chlorination, activated carbon) reduced pesticide concentrations to levels well below USEPA drinking-water standards. In particular, the percentage of pesticides remaining in treated water samples decreased significantly for several frequently occurring pesticides when the plant replaced the use of powdered activated carbon with granular activated carbon in November 1999. For example, the median percentage of atrazine remaining after treatment that included powdered activated carbon was 63 percent, whereas the median percentage of atrazine remaining after the switch to granular activated carbon was 2.4 percent.

  9. 40 CFR 152.8 - Products that are not pesticides because they are not for use against pests.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 2010-07-01 false Products that are not pesticides because they are not for use against pests. ...ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS PESTICIDE REGISTRATION AND CLASSIFICATION PROCEDURES...

  10. Long-term lessons on pesticide leaching obtained via the Danish Pesticide Leaching Assessment Programme

    NASA Astrophysics Data System (ADS)

    Rosenbom, A. E.; Olsen, P.; Plauborg, F.; Grant, R.; Juhler, R. K.; Brüsch, W.; Kjær, J.

    2014-12-01

    To avoid any unacceptable influence on the environment posed by pesticides and their degradation products, all pesticides used in the European Union needs authorization. The authorization procedure includes assessing the leaching risk of both pesticides and their degradation products to the groundwater. There are shortcomings to the procedure, however, as revealed by the results of the Danish Pesticide Leaching Assessment Programme from the period 1990/2000 to 2012 (app. twelve years). This monitoring program has for this period assessed leaching into groundwater via the variably-saturated zone of 43 pesticides applied in accordance with current regulations on sandy and loamy agricultural fields, and 47 of their degradation products. Three types of leaching scenario were not fully captured by the authorization procedure: i) long-term leaching of degradation products of pesticides applied on potato crops cultivated in sandy soils, ii) leaching of strongly sorbing pesticides after autumn application on loamy soils, and iii) leaching of various pesticides and their degradation products following early summer application on loamy soils. The monitoring data revealed that the authorization procedure was unable to predict leaching scenarios for a number of pesticides in hydrogeological settings dominated by rapid preferential transport via e.g. biopores that bypasses the retardation (sorption and degradation) of the plow layer. Such settings are primarily present in the autumn, but can also occur during the early summer in connection with the formation of a structural seal on the soil surface.

  11. 75 FR 11175 - Pesticide Products; Registration Applications

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-10

    ...NCA Biotech Incorporated, 3406 Pomona Boulevard, Pomona, CA 91768. Product Name: Technical Salicylic Acid. Active Ingredient: Salicylic Acid at 98.7%. Proposed Classification/Use: Manufacturing-use product for formulation into...

  12. Partial degradation of five pesticides and an industrial pollutant by ozonation in a pilot-plant scale reactor.

    PubMed

    Maldonado, M I; Malato, S; Pérez-Estrada, L A; Gernjak, W; Oller, I; Doménech, Xavier; Peral, José

    2006-11-16

    Aqueous solutions of a mixture of several pesticides (alachlor, atrazine, chlorfenvinphos, diuron and isoproturon), considered PS (priority substances) by the European Commission, and an intermediate product of the pharmaceutical industry (alpha-methylphenylglycine, MPG) chosen as a model industrial pollutant, have been degraded at pilot-plant scale using ozonation. This study is part of a large research project [CADOX Project, A Coupled Advanced Oxidation-Biological Process for Recycling of Industrial Wastewater Containing Persistent Organic Contaminants, Contract No.: EVK1-CT-2002-00122, European Commission, http://www.psa.es/webeng/projects/cadox/index.html] founded by the European Union that inquires into the potential coupling between chemical and biological oxidations for the removal of toxic or non-biodegradable contaminants from water. The evolution of pollutant concentration, TOC mineralization, generation of inorganic species and consumption of O3 have been followed in order to visualize the chemical treatment effectiveness. Although complete mineralization is hard to accomplish, and large amounts of the oxidant are required to lower the organic content of the solutions, the possibility of ozonation cannot be ruled out if partial degradation is the final goal wanted. In this sense, Zahn-Wellens biodegradability tests of the ozonated MPG solutions have been performed, and the possibility of a further coupling with a secondary biological treatment for complete organic removal is envisaged. PMID:16822610

  13. Heterogeneous photocatalytic degradation of pesticides using decatungstate intercalated macroporous layered double hydroxides.

    PubMed

    Da Silva, Eliana S; Prevot, Vanessa; Forano, Claude; Wong-Wah-Chung, Pascal; Burrows, Hugh D; Sarakha, Mohamed

    2014-10-01

    Decatungstate W10O32(4-) was efficiently intercalated between the layers of three-dimensionally ordered macroporous Mg2Al-layered double hydroxide. The structural and textural properties of as-prepared intercalated compound were characterized using different solid-state characterization techniques such as X-ray powder diffraction, FTIR and Raman spectroscopies and electronic microscopy. The photocatalytic properties of immobilized W10O32 (4-) within Mg2Al structure were investigated using 2-(1-naphthyl) acetamide (NAD) as a model of pesticide. The influence of different parameters such as amount of catalyst, pH and oxygen concentration were investigated. An optimal NAD degradation was obtained for a photocatalyst concentration of 60 mg l(-1). Under our experimental conditions, this heterogeneous photocatalyst induces photodegradation of 60 % of NAD after 17 h of irradiation at 365 nm and at pH 6.6. Interestingly, pesticide photodegradation leads to the mineralization of substrates to H2O and CO2 and the photocatalyst can be recycled and reused without any loss of activity over four cycles. PMID:24838128

  14. 75 FR 11174 - Pesticide Product Registration Approval

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-10

    ...Immunocontraceptive Vaccine containing an active ingredient not included...Immunocontraceptive Vaccine, contraceptive...03% active ingredient. This product...Immunocontraceptive Vaccine contraceptive...for this active ingredient one comment...

  15. 77 FR 38285 - Pesticide Products; Registration Applications

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-27

    ...EPA-HQ-OPP-2011-0971. Applicant: Nichino America, Inc., 4550 New Linden Hill Road, Suite 501, Wilmington, DE 19808. Product name...EPA-HQ-OPP-2011-0971. Applicant: Nichino America, Inc., 4550 New Linden Hill Road, Suite 501, Wilmington, DE 19808. Product...

  16. 75 FR 19388 - Pesticide Product; Registration Application

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-14

    ...receipt of this application does not imply a decision by the Agency on the application. File Symbol: 524-LOU. Applicant: Monsanto Company, 1300 I St., NW., Suite 450 East, Washington, DC 20005. Product name: MON 87701. Active ingredient:...

  17. 75 FR 34114 - Pesticide Products; Registration Applications

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-16

    ...Triangle Park, NC 27709. Product name: PENCLO 273.5FS. Active ingredient: Fungicide with Penflufen at 6.0% and Clothianidin at 18.6%. Proposed classification/Use: Seed treatment on cotton. Contact: Marianne Lewis, (703)...

  18. 75 FR 23759 - Pesticide Products; Registration Applications

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-04

    ...7969-GNN. Applicant: BASF Corporation, 26 Davis Drive, P.O. Box 13528, Research Triangle Park, NC, 27709. Product name: BAS 650 00F. Active ingredient: Ametoctradin at 19.2%. Proposed classification/Use: Terrestrial food use for brassica...

  19. 77 FR 12295 - Pesticide Products; Registration Applications

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-29

    ...limited to: Crop production...Co., 1007 Market St., Wilmington...and Syngenta Crop Protection LLC...Technical, Benevia Insect Control, Exirel Insect...Tree Injection Insect Control; Syngenta...vegetables (crop subgroup...

  20. 76 FR 5805 - Pesticide Products; Registration Applications

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-02

    ...ingredient: Plant growth regulator, Salicylic Acid, at 0.04%. Proposed classification...ingredient: Plant growth regulator, Salicylic Acid, at 0.0067%. Proposed classification...Harbor, WA 98332. Product name: Salicylic Acid Technical. Active...

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

    PubMed

    Thomas, Kevin A; Hand, Laurence H

    2011-03-01

    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

  2. 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...

  3. Polar-Organic-Chemical-Integrative Sampler (POCIS) uptake rates for 17 polar pesticides and degradation

    E-print Network

    Boyer, Edmond

    1 Polar-Organic-Chemical-Integrative Sampler (POCIS) uptake rates for 17 polar pesticides of chemicals, including polar pesticides, in water bodies. However, few calibration data are available, which pesticides (1.15 logKow 3.71) commonly found in water. The experiment, conducted for 21 days

  4. Pesticide and transformation product detections and age-dating relations from till and sand deposits

    USGS Publications Warehouse

    Warner, K.L.; Morrow, W.S.

    2007-01-01

    Pesticide and transformation product concentrations and frequencies in ground water from areas of similar crop and pesticide applications may vary substantially with differing lithologies. Pesticide analysis data for atrazine, metolachlor, alachlor, acetochlor, and cyanazine and their pesticide transformation products were collected at 69 monitoring wells in Illinois and northern Indiana to document occurrence of pesticides and their transformation products in two agricultural areas of differing lithologies, till, and sand. The till is primarily tile drained and has preferential fractured flow, whereas the sand primarily has surface water drainage and primary porosity flow. Transformation products represent most of the agricultural pesticides in ground water regardless of aquifer material - till or sand. Transformation products were detected more frequently than parent pesticides in both the till and sand, with metolachlor ethane sulfonic acid being most frequently detected. Estimated ground-water recharge dates for the sand were based on chlorofluorocarbon analyses. These age-dating data indicate that ground water recharged prior to 1990 is more likely to have a detection of a pesticide or pesticide transformation product. Detections were twice as frequent in ground water recharged prior to 1990 (82%) than in ground water recharged on or after 1990 (33%). The highest concentrations of atrazine, alachlor, metolachlor, and their transformation products, also were detected in samples from ground water recharged prior to 1990. These age/pesticide detection relations are opposite of what would normally be expected, and may be the result of preferential flow and/or ground-water mixing between aquifers and aquitards as evident by the detection of acetochlor transformation products in samples with estimated ground-water ages predating initial pesticide application. ?? 2007 American Water Resources Association.

  5. 78 FR 25438 - Product Cancellation Order for Certain Pesticide Registrations

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-01

    ...Select Source, LLC., Agent: Wagner Regulatory Associates, Inc., P.O. Box 640, Hockessin...protection, Pesticides and pests. Dated: April 23, 2013. Richard P. Keigwin, Jr., Director, Pesticide Re-Evaluation...

  6. Organochlorine pesticide residues in dairy products in Jordan.

    PubMed

    Salem, Nida' M; Ahmad, Rafat; Estaitieh, Hussein

    2009-10-01

    The use of aldrin, dieldrin, endrin, heptachlor and hexachlorobenzene (HCB) has been banned in Jordan officially in 1981, and of dichlorodiphenyltrichloroethane (DDT) in 1995. However, residues of such compounds can still be found in the environment and in foodstuffs. Dairy products are an important exposure route for organochlorine pesticides (OCPs) to humans. For this reason, the presence of OCP residues in 233 dairy product samples; comprising milk, butter, cheese, labaneh and yoghurt collected from Jordan was determined. All samples were analyzed for their residual contents of aldrin, DDT and metabolites (DDTs), dieldrin, endosulfan isomers, endrin, hexachlorocyclohexane isomers (HCHs), heptachlor and HCB. Levels of these compounds were determined by gas chromatography with electron capture detector (GC-ECD). The results indicated that 9% (21/233), 8.5% (20/233), 6% (14/233) and 2.1% (5/233) of the examined samples were contaminated with beta-HCH, pp'-DDE, alpha-HCH and gamma-HCH, respectively. Heptachlor and alpha-endosulfan were only present in less than 2% of the analyzed samples. None of the samples revealed the presence of aldrin, op'-DDD, pp'-DDD, op'-DDE, op'-DDT, pp'-DDT, dieldrin, beta-endosulfan, endrin and HCB at their detection limits. The order for the contamination in the analyzed dairy products was labaneh>cheese>yoghurt>butter>milk. This study has provided the preliminary information on the concentration of OCPs in dairy products for the first time in Jordan. The results will help in a scientific assessment of the implications of pesticide residues with regards to human risks in Jordan. PMID:19695668

  7. Properties and degradability of hydrothermal carbonization products.

    PubMed

    Eibisch, Nina; Helfrich, Mirjam; Don, Axel; Mikutta, Robert; Kruse, Andrea; Ellerbrock, Ruth; Flessa, Heinz

    2013-09-01

    Biomass carbonized via hydrothermal carbonization (HTC) yields a liquid and a carbon (C)-rich solid called hydrochar. In soil, hydrochars may act as fertilizers and promote C sequestration. We assumed that the chemical composition of the raw material (woodchips, straw, grass cuttings, or digestate) determines the properties of the liquid and solid HTC products, including their degradability. Additionally, we investigated whether easily mineralizable organic components adsorbed on the hydrochar surface influence the degradability of the hydrochars and could be removed by repetitive washing. Carbon mineralization was measured as CO production over 30 d in aerobic incubation experiments with loamy sand. Chemical analysis revealed that most nutrients were preferably enriched in the liquid phase. The C mineralization of hydrochars from woodchips (2% of total C added), straw (3%), grass (6%), and digestate (14%) were dependent on the raw material carbonized and were significantly lower (by 60-92%; < 0.05) than the mineralization of the corresponding raw materials. Washing of the hydrochars significantly decreased mineralization of digestate-hydrochar (up to 40%) but had no effect on mineralization rates of the other three hydrochars. Variations in C mineralization between different hydrochars could be explained by multiple factors, including differences in the O/C-H/C ratios, C/N ratios, lignin content, amount of oxygen-containing functional groups, and pH. In contrast to the solids, the liquid products were highly degradable, with 61 to 89% of their dissolved organic C being mineralized within 30 d. The liquids may be treated aerobically (e.g., for nutrient recovery). PMID:24216434

  8. Photocatalytic degradation of organophosphorus pesticides using floating photocatalyst TiO 2 · SiO 2\\/beads by sunlight

    Microsoft Academic Search

    Chen Shifu; Cao Gengyu

    2005-01-01

    In this paper, the floating TiO2·SiO2 photocatalyst beads are prepared by the dip-coating method, which use hollow glass microbeads as the carrier and titanium tetraisopropoxide [Ti(iso-OC3H7)4] and ethyl silicate as the raw materials. The feasibility of photocatalytic degradation of organophosphorus pesticides using TiO2·SiO2 beads as a floating photocatalyst by sunlight is studied. The results show that the best heat treatment

  9. Original article The significance of the degradation products

    E-print Network

    Boyer, Edmond

    Original article The significance of the degradation products of rapeseed meal proteins of four rapeseed oilmeals (60% hay, 40% meals). Oilmeal batches originated from different heating system). (© Elsevier / Inra) rapeseed meal / technological processes / nitrogen degradation / rumen

  10. 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...

  11. Determination of organochlorine pesticides in agricultural soil with special reference to ?-HCH degradation by Pseudomonas strains

    Microsoft Academic Search

    Akbar Nawab; Asma Aleem; Abdul Malik

    2003-01-01

    Soil samples were taken from different agricultural fields and analyzed for organochlorine pesticide residues by gas chromatography. The analysis indicated that the soil samples contained some common organochlorine pesticides DDT, DDD, DDE, HCH and Aldrin. ?-HCH was detected as 47.35 ppb whereas the concentrations of ?-HCH, ?-HCH, p?,p?-DDE, o?,p?-DDT were 38.81, 1.79, 7.10 and 13.30 ppb, respectively, in the same

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

    Microsoft Academic Search

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

    2007-01-01

    Stored product mites can often infest stored products, but currently there is little information regarding the efficacy of\\u000a pesticides that can be used for control. In this study we evaluated several common pesticides formulated from single active\\u000a ingredients (a.i.) or commercially available mixtures (chlorpyrifos, deltamethrin, beta-cyfluthrin, and a combination of deltamethrin\\u000a and S-bioallethrin), plus an acaricide composed of permethrin, pyriproxyfen

  13. 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...

  14. 77 FR 10515 - Pesticide Product Registrations; Conditional Approval

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-22

    ...are an agricultural producer, food manufacturer, or pesticide...used as an antimicrobial and preservative additive used to treat fibers, plastics...1), an antimicrobial and preservative additive used to treat fibers....

  15. Advice on Degradation Products in Pharmaceuticals: A Toxicological Evaluation.

    PubMed

    Melo, Sâmia Rocha de Oliveira; Homem-de-Mello, Maurício; Silveira, Dâmaris; Simeoni, Luiz Alberto

    Degradation products are unwanted chemicals that can develop during the manufacturing, transportation, and storage of drug products and can affect the efficacy of pharmaceutical products. Moreover, even small amounts of degradation products can affect pharmaceutical safety because of the potential to cause adverse effects in patients. Consequently, it is crucial to focus on mechanistic understanding, formulation, storage conditions, and packaging to prevent the formation of degradation products that can negatively affect the quality and safety of the drug product. In this sense, databases and software that help predict the reactions involving the pharmaceutically active substance in the presence of degradation conditions can be used to obtain information on major degradation routes and the main degradation products formed during pharmaceutical product storage. In some cases, when the presence of a genotoxic degradation product is verified, it is necessary to conduct more thorough assessments. It is important to consider the chemical structure to distinguish between compounds with toxicologically alerting structures with associated toxic/genotoxic risks and compounds without active structures that can be treated as ordinary impurities. Evaluating the levels of degradation products based on a risk/benefit analysis is mandatory. Controlling critical variables during early development of drug products and conducting a follow-up study of these impurities can prevent degradation impurities present at concentrations greater than threshold values to ensure product quality. The definition of the impurity profile has become essential per various regulatory requirements. Therefore, this review includes the international regulatory perspective on impurity documents and the toxicological evaluation of degradation products. Additionally, some techniquesused in the investigation of degradation products and stability-indicating assay methods are highlighted. PMID:25188345

  16. Pesticide residue monitoring in Korean agricultural products, 2003–05

    Microsoft Academic Search

    T. H. Cho; B. S. Kim; S. J. Jo; H. G. Kang; B. Y. Choi; M. Y. Kim

    2009-01-01

    Between 2003 and 2005, a total of 11,716 samples were collected and analysed to determine the level of pesticides residues. Multi-residue methods (MRMs) capable of simultaneously determining 250 pesticides were used. Of the 11,716 samples, 89.1% had no detectable residues and 1.7% had violative residues. The detection rates by commodity group were 11.4, 8.6, 0.3, and 0.02% for vegetables, fruit,

  17. 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...

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

    PubMed

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

    2012-09-01

    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

  19. 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...

  20. DEVELOPMENT OF A STRUCTURE-SEARCHABLE DATABASE FOR PESTICIDE METABOLITES AND ENVIRONMENTAL DEGRADATES

    EPA Science Inventory

    USEPA is modifying and enhancing existing software for the depiction of metabolic maps to provide access via structures to metabolism information and associated data in EPA's Office of Pesticide Programs (OPP). The database includes information submitted to EPA in support of pest...

  1. Rapid Analysis of Multiresidual Pesticides in Agricultural Products by Gas Chromatography-mass Spectrometry

    Microsoft Academic Search

    Libin Liu; Hashi Yuki; Yaping Qin; Haixia Zhou; Jinming Lin

    2006-01-01

    A method for the rapid analysis of multiresidual pesticides in agricultural products using gas chromatography-mass spectrometry (GC\\/MS) was introduced. The matrix solid-phase dispersion (MSPD) technique with slight modification was employed to minimize the matrix interferences. To calculate the recovery, 97 target pesticides were spiked into a range of foods including potato, cabbage, carrot, apple, orange, cucumber, and rice. The combination

  2. Degradation products of rubusoside under acidic conditions.

    PubMed

    Prakash, Indra; Bunders, Cynthia; Devkota, Krishna P; Charan, Romila D; Hartz, Rachael M; Sears, Tracy L; Snyder, Tara M; Ramirez, Catherine

    2015-04-01

    A natural sweetener, Rubusoside (1), subjected to extreme pH and temperature conditions, resulted in the isolation and structural elucidation of one novel rubusoside degradant (7), together with seven known degradants (2-6 and 8-9). ID and 2D NMR spectroscopy (1H, 13C, COSY, HSQC-DEPT, HMBC, and NOESY) and mass spectral data were used to fully characterize the degradant 7. PMID:25973475

  3. Microbial petroleum degradation enhancement by oil spill bioremediation products 

    E-print Network

    Lee, Salvador Aldrett

    1996-01-01

    was conducted using unpolluted, natural seawater. The products were tested in triplicate using 250 ml Erlenmeyer flasks and evaluated over a 28 day period to determine the products' capabilities based on the extent of petroleum degradation. Toxicity...

  4. Pesticide fate in an aboveground disposal system 

    E-print Network

    Vanderglas, Brian Richard

    1988-01-01

    application. The persistence of pesticides is this study may have resulted from its distribution in the digester, and the lack of pesticide degraders in the digestion media. It can also be attributed to the deleterious and inhibitory effects pesticide..., pesticide wastewater disposal system. This study had the following objectives: (1) to determine how mixtures of pesticides affect pesticide degradation and adsorption in the disposal unit; (2) to determine how increasing the concentrations of pesticides...

  5. 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...

  6. Research of the degradation products of chitosan's angiogenic function

    NASA Astrophysics Data System (ADS)

    Wang, Jianyun; Chen, Yuanwei; Ding, Yulong; Shi, Guoqi; Wan, Changxiu

    2008-11-01

    Angiogenesis is of great importance in tissue engineering and has gained large attention in the past decade. But how it will be influenced by the biodegradable materials, especially their degradation products, remains unknown. Chitosan (CS) is a kind of naturally occurred polysaccharide which can be degraded in physiological environment. In order to gain some knowledge of the influences of CS degradation products on angiogenesis, the interaction of vascular endothelial cells with the degradation products was investigated in the present study. The CS degradation products were prepared by keeping CS sample in physiological saline aseptically at 37 °C for 120 days. Endothelial cells were co-cultured with the degradation products and the angiogenic cell behaviors, including cell proliferation, migration and tube-like structure (TLS) formation, were tested by MTT assay, cell migration quantification method (CMQM), and tube-like structure quantification method (TLSQM) respectively. Furthermore, mRNA expressions of vascular endothelial growth factor (VEGF) and matrix metallo proteinase (MMP-2) were determined by real-time reverse transcriptional polymerase chain reaction (RT-PCR). Physiological saline served as a negative control. As the results showed, the degradation products obtained from 20th to 60th day significantly inhibited the proliferation, migration, and TLS formation of endothelial cells. However, degradation products of the first 14 days and the last 30 days were found to be proangiogenic. At the molecular level, the initial results indicated that the mRNA expressions of VEGF and MMP-2 were increased by the degradation products of 7th day, but were decreased by the ones of 60th day. According to all the results, it could be concluded that the angiogenic behaviors of endothelial cells at both cellular and molecular level could be significantly stimulated or suppressed by the degradation products of CS and the influences are quite time-dependent.

  7. Phototherapy Increases Hemoglobin Degradation and Bilirubin Production in Preterm Infants

    Microsoft Academic Search

    Moustafa M Aouthmany

    1999-01-01

    OBJECTIVE:To compare hemoglobin degradation and bilirubin production before and during phototherapy in preterm infants.BACKGROUND:Hemoglobin is catabolized into globin and heme, which is degraded by microsomal heme oxygenase into equimolar carbon monoxide and biliverdin. Biliverdin is then reduced into bilirubin. CO is excreted exclusively by the lungs; therefore, end-tidal carbon monoxide, corrected for inhaled CO (ETCOc), reflects hemoglobin degradation and total

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

    NASA Astrophysics Data System (ADS)

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

    2014-05-01

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

  9. Pesticide Movement

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pesticides generally include herbicides, insecticides and fungicides that play an important role in maintaining worldwide food and fiber production by controlling weeds that compete for water and nutrients or by eliminating pests that reduce yields. In the future, the role of pesticides and fertili...

  10. Pesticide and metabolite fate, release and transport modelling at catchment scale

    Microsoft Academic Search

    Matthias Gaßmann; Oliver Olsson; Melanie Bauer

    2010-01-01

    Pesticides are of great concern in hydrological catchments all over the world. On the one hand they are necessary to guarantee stable agricultural production for an increasing population. On the other hand they endanger life of aquatic animals and freshwater resources. However, not only pesticides but also their degradation products, the metabolites, are toxic to the environment, in some cases

  11. 78 FR 3418 - Pesticides; Draft Guidance for Pesticide Registrants on Web-Distributed Labeling for Pesticide...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-16

    ...Draft Guidance for Pesticide Registrants on Web- Distributed Labeling for Pesticide Products...Registration Notice (PR Notice) titled ``Web-Distributed Labeling for Pesticide Products...labeling available through the Internet. Web-distributed labeling would allow...

  12. Photocatalytic degradation of pesticide pyridaben. 3. In surfactant/TiO2 aqueous dispersions.

    PubMed

    Zhu, Xinle; Yuan, Chunwei; Chen, Huilan

    2007-01-01

    The effective TiO2 photocatalytic degradation of pyridaben in an acetronitrile/water dispersion has been investigated in previous work, but could not be achieved in the case of real waters. In this paper, photocatalytic degradation of pyridaben on TiO2 particles under UV light (lambda> 360 nm) illumination in surfactant CTAB (cetyltrimethyl ammonium bromide) aqueous dispersions was studied. 1H NMR was used to determine quantitative information about the adsorption mode of pyridaben in CTAB micelles. The results showed that the upfield 1H shifts were largest for long chain protons of CTAB, indicating that the hydrophobic aromatic rings were primarily located in this region. Adsorption models on TiO2 surface were thus proposed. The reaction rates decreased with the increase of pH value, which can be attributed to the surface charge variations of pyridaben adsorbed onto TiO2 particles. The adsorption isotherms at different pH values confirmed that preadsorption on the surface of TiO2 particles was prerequisite for efficient degradation. Furthermore, an oxidation reagent such as H2O2 was added to the photocatalytic system, which may act as an alternative electron acceptor and result in a notably enhanced rate of pollutant destruction. On the basis of intermediates identified by GC/MS, a degradation pathway was proposed. PMID:17265957

  13. Validation of Multiresidue Screening Methods for the Determination of 186 Pesticides in 11 Agricultural Products Using Gas Chromatography (GC)

    Microsoft Academic Search

    Yoshichika Hirahara; Mika Kimura; Tomoko Inoue; Seiji Uchikawa; Shoji Otani; Asami Haganuma; Nobuyuki Matsumoto; Asumi Hirata; Shiho Maruyama; Tomomi Iizuka; Masaho Ukyo; Mitsue Ota; Hideaki Hirose; Sosuke Suzuki; Yukinori Uchida

    2005-01-01

    Validation of multiresidue screening methods for the determination of 186 pesticides in 11 agricultural products: broccoli, asparagus, carrot, spinach, bur- dock, matsutake mushroom, cauliflower, orange, soy- bean, sesame and millet was done by gas chromatog- raphy (GC). The investigated pesticides were selected on the based of such compounds that are commonly used around the world. Although the recovery of 58

  14. Life cycle toxicity assessment of pesticides used in integrated and organic production of oranges in the Comunidad Valenciana, Spain

    Microsoft Academic Search

    Ronnie Juraske; Neus Sanjuán

    2011-01-01

    The relative impacts of 25 pesticides including acaricides, fungicides, herbicides, insecticides, and post-harvest fungicides, used in the production of oranges in Spain were assessed with current life cycle impact assessment (LCIA) tools. Chemical specific concentrations were combined with pesticide emission data and information on chemical toxicity to assess human toxicity and freshwater ecotoxicity impacts. As a case study, the relative

  15. Surface water pesticide modelling for decision support in drinking water production

    NASA Astrophysics Data System (ADS)

    Desmet, Nele; Dams, Jef; Bronders, Jan; Peleman, Gisèle; Verdickt, Liesbeth

    2015-04-01

    The occurrence of pesticides and other contaminants in river systems may compromise the use of surface water for drinking water production. To reduce the cost of removal of pesticides from the raw water, drinking water companies can: search for other raw water sources, invest in water storage capacity to overcome periods with high pesticide concentrations (often related to the application period), or impose measures to reduce the emission of pesticides to surface water (i.e. sustainable application strategies or use restrictions). To select the most appropriate water management options, the costs and effects of the aforementioned actions need to be evaluated. This evaluation requires knowledge on the concentrations and loads of pesticides at the point of drinking water abstraction, as well as insight in the contribution and the temporal variability of different sources or subbasins. In such a case, a modelling approach can assist in generating measurement-based datasets and to compare different scenarios for water management. We illustrate how a modelling approach can provide decision support for water management related to drinking water abstraction from surface water in a catchment that suffers from elevated pesticide concentrations. The study area is a water production center (WPC) located in northwestern Belgium. The WPC abstracts raw water from the river IJzer or from a natural pond and its connected streams. The available quantities as well as the quality of the water vary throughout the year. The WPC uses a reservoir of 3 million m³ to capture and store raw water to overcome periods with limited water availability and/or poor water quality. However, the pressure on water increases and in the future this buffering capacity might be no longer sufficient to fulfill the drinking water production demand. A surface water quality model for the area is set up using InfoWorks RS. The model is applied to obtain insight in the concentrations and loads at the different points of drinking water abstraction (river IJzer and Blankaart pond), the contribution of the subbasins, and the seasonal dynamics. The model is also applied for scenario analysis related to water management and varying climatological conditions. Especially in summer, the availability of raw water of good quality for the WPC is limited. The discharge of the river IJzer is low and a minimum level is required for navigation, and the pond is part of a nature reserve where a minimum water level is imposed for conservation of aquatic habitats, and application of pesticides on the surrounding agricultural lands results in high pesticide concentrations (e.g. bentazon > 1µg/L).

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

    USGS Publications Warehouse

    Ellis, D.H.

    1985-01-01

    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.

  17. Toxicity of pesticides associated with potato production, including soil fumigants, to snapping turtle eggs (Chelydra serpentina).

    PubMed

    de Solla, Shane Raymond; Palonen, Kimberley Elizabeth; Martin, Pamela Anne

    2014-01-01

    Turtles frequently oviposit in soils associated with agriculture and, thus, may be exposed to pesticides or fertilizers. The toxicity of a pesticide regime that is used for potato production in Ontario on the survivorship of snapping turtle (Chelydra serpentina) eggs was evaluated. The following treatments were applied to clean soil: 1) a mixture of the pesticides chlorothalonil, S-metolachlor, metribuzin, and chlorpyrifos, and 2) the soil fumigant metam sodium. Turtle eggs were incubated in soil in outdoor plots in which these mixtures were applied at typical and higher field application rates, where the eggs were subject to ambient temperature and weather conditions. The pesticide mixture consisting of chlorothalonil, S-metolachlor, metribuzin, and chlorpyrifos did not affect survivorship, deformities, or body size at applications up to 10 times the typical field application rates. Hatching success ranged between 87% and 100% for these treatments. Metam sodium was applied at 0.1¯ times, 0.3¯ times, 1 times, and 3 times field application rates. Eggs exposed to any application of metam sodium had 100% mortality. At typical field application rates, the chemical regime associated with potato production does not appear to have any detrimental impacts on turtle egg development, except for the use of the soil fumigant metam sodium, which is highly toxic to turtle eggs at the lowest recommended application rate. PMID:24105794

  18. 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

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

    2008-01-01

    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.

  19. Qualitative Profiling of Polyglucose Degradation Products in Peritoneal Dialysis Fluids.

    PubMed

    Gensberger, Sabrina; Knabner, Carina; Waibel, Reiner; Huppert, Jochen; Pischetsrieder, Monika

    2015-06-16

    Heat sterilization of peritoneal dialysis (PD) fluids leads to partial degradation of the osmotic agent to form reactive carbonyl structures, which significantly reduce the biocompatibility of PD fluids and impair long-term PD therapy. Hence, it is important to know the exact composition of the degradation products to improve biocompatibility of PD fluids. Our study conducted targeted screening for degradation products in polyglucose (icodextrin)-containing PD fluids (pGDPs) by applying o-phenylenediamine (OPD) to form stable derivatives, which were analyzed by ultrahigh-performance liquid chromatography with hyphenated diode array tandem mass spectrometry (UHPLC-DAD-MS/MS). For the first time, specific degradation products of polyglucose, namely, 4-deoxyglucosone (4-DG) and 3,4-dideoxypentosone (3,4-DDPS), could be identified in PD fluids. Further, a reaction product of 5-hydroxymethylfurfural (5-HMF) and OPD could be characterized to be (5-(1H-benzo[d]imidazol-2-yl)furan-2-yl)methanol. Additionally, 3-deoxyglucosone (3-DG) and 3-deoxygalactosone (3-DGal), both known to be present in glucose-based PD fluids, were also detected in polyglucose-containing fluids. Trapping a hitherto unknown degradation product with OPD yielded 1,4-bis(1H-benzo[d]imidazol-2-yl)-3,4-dihydroxybutan-1-one, which was present in heat- as well as filter-sterilized PD fluids. PMID:25970747

  20. Comparison of linuron degradation in the presence of pesticide mixtures in soil under laboratory conditions.

    PubMed

    Swarcewicz, Maria; Gregorczyk, Andrzej; Sobczak, Justyna

    2013-10-01

    It is widely recognised that complex interactions occur between chemicals in mixtures. In many agricultural situations, the use of tank mixes and complex spray programs is a common practice. Insecticides, fungicides and a herbicide being applied in potato protection were used in this research. Interactions between linuron and insecticides, such as thiamethoxam or clothianidin, and fungicides, such as mancozeb or chlorothalonil, were examined in soil. The degradation rate of linuron in soil during laboratory incubation in six treatments was studied. Mixtures of linuron with mancozeb in sandy loam and clay loam soils had a significant effect on the persistence of this herbicide. For example, for the same herbicide, t 1/2 values for linuron were from 37 days in sandy loam to 44 days in clay loam. These values changed (64-67 days) when thiamethoxam and mancozeb were in soil. When mancozeb was added only, the half-life values were from 59 to 62 days, respectively. Other mixtures with chlorothalonil, thiamethoxam and clothianidin did not have any effect. In order to compare linuron degradation rates in soils, a single first-order model and expanded statistical analysis were used. PMID:23525775

  1. 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 ...

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

    Microsoft Academic Search

    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

    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

  3. Dioxin/POPs legacy of pesticide production in Hamburg: part 1--securing of the production area.

    PubMed

    Weber, Roland; Varbelow, Hans Gerhard

    2013-04-01

    ?-Hexachlorocyclohexane (HCH), ?-HCH, and ?-HCH (lindane) were recently included as new persistent organic pollutants (POPs) in the Stockholm Convention. Therefore, the chemicals need to be globally addressed, including the disposal of historic wastes. At most sites, the approximately 85% of HCH waste isomers were dumped. At a former lindane factory in Hamburg and some other factories the HCH, waste was recycled producing residues with high polychlorinated dibenzo-p-dioxin and dibenzofuran (PCDD/PCDF) levels. The soil and ground water under the former pesticide factory was/is highly contaminated with HCH (260 tons), chlorobenzenes (550 tons), and PCDD/PCDF (6 kg toxic equivalents (TEQ)). This contamination did not result from disposal operations but from spillages and leakages during the 30 years of the factory's production history. A containment wall has been constructed around the production area to prevent the dispersal of the pollutants. The ground water is managed by a pump and treat system. Over the last 15 years, approximately 10-30 tons of this pollution reservoir has been pumped and incinerated. For the contaminated production buildings, specific assessment and demolition technologies have been applied. In addition to their HCH waste isomer deposition, former lindane/HCH productions need to be assessed for possible recycling practice of HCH and related PCDD/PCDF contamination of the production area and buildings. Since such recycling activities have taken place at several factories in different countries, the experience of assessment and management of the described production area and contaminated buildings could be valuable. Such assessment could be addressed within the frame of the Stockholm Convention. PMID:22777609

  4. 76 FR 17607 - Receipt of Request To Require Pesticide Products To Be Labeled in English and Spanish

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-30

    ...labeling on your pesticide products? 14. How could electronic media be used to facilitate distribution of bilingual or multilingual labeling? 15. Apart from bilingual labeling, what past and current efforts have you made to communicate with...

  5. [Studies on simultaneous determination of 17 organochlorine and 9 pyrethroid pesticides of agricultural products].

    PubMed

    Nemoto, S; Tyuda, Y; Nagao, A; Sasaki, K; Toyoda, M

    1999-01-01

    A method for simultaneous determination of 17 organochlorine and 9 pyrethroid pesticides in agricultural products by capillary GC with ECD detection was studies. The samples were extracted with acetone under acidic conditions followed by Florisil column clean-up and then injected into a GC-ECD. The organochlorine pesticides used in this study included unstable captan and captafol in the homogenized preparations of fruits and vegetables. Captan and captafol were also found to decompose in rice and wheat samples when the samples were allowed to stand after the addition of water. Addition of phosphoric acid to the samples was effective in preventing the decomposition of captan and captafol. Recovery of the pesticides investigated in this study was not decreased by the addition of phosphoric acid. Addition of phosphoric acid was also effective in removing interfering substances from onion extract. Recovery of organochlorine and pyrethroid pesticides from samples spiked at levels of 0.05-0.25 ppm by the proposed method was 51.4-100.8% for rice and wheat and 60.1-119.0% for vegetables. PMID:10939848

  6. [Validation study on a multi-residue method for determination of pesticides in agricultural products by LC-MS/MS].

    PubMed

    Ueno, Eiji; Watanabe, Minae; Umemura, Yuko; Inoue, Tomomi; Ikai, Yoshitomo

    2014-01-01

    A multi-residue method for 122 pesticides in agricultural products was validated in accordance with Japanese guidelines for residual agricultural chemicals in food. The sample was extracted with acetonitrile. Co-extractives were removed by GPC-graphitized carbon column SPE, followed by silica gel/PSA cartridge column SPE. The pesticides in the test solution were determined by LC-MS/MS using scheduled MRM in combination with polarity switching. Validation tests were performed on spinach, brown rice, soybean, orange and tomato fortified at 0.01 and 0.1 ?g/g. The pesticides at each level were analyzed in two samples per day on five different days. In conclusion, among 122 pesticides tested for each level, 121 pesticides (but not disulfoton) were found to meet all of the guideline criteria. PMID:25743592

  7. A general model for estimating the economic and production effects of specified pesticide withdrawals: a cotton application 

    E-print Network

    Casey, James Elmer

    1973-01-01

    A GENERAL MODEL FOR ESTIMATING THE ECONOMIC AND PRODUCTION EFFECTS OF SPECIFIED PESTICIDE WITHDRAWALS: A COTTON APPLICATION A Thesis by JAMES E(~CASEY, JR. Submitted to the Graduate College of Texas A&M University in partial fulfillment... of the requirement for the degree of MASTER OF SCIENCE December 1973 Major Subject: Agricultural Economics A GENERAL MODEL FOR ESTIMATING THE ECONOMIC AND PRODUCTION EFFECTS OF SPECIFIED PESTICIDE WITHDRAWALS: A COTTON APPLICATION A Thesis by JAMES E. CASEY...

  8. 75 FR 44247 - Product Cancellation Order for Certain Pesticide Registrations

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-28

    ...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...

  9. 78 FR 57388 - Product Cancellation Order for Certain Pesticide Registrations

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-18

    ...manufacturing products, listed in Table 1 of Unit II., will be effective...the 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...

  10. 78 FR 24195 - Product Cancellation Order for Certain Pesticide Registrations

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-24

    ...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...

  11. 75 FR 52737 - Pesticide Product Registrations; Unconditional and Conditional Approvals

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-27

    ...ingredient: EPA received an application from Plasma Power Limited of India, c/o OMC Ag...for the registration of two products: Plasma Neem Oil Manufacturing Use Product EPA...one end-use product was registered: Plasma Neem Oil Biological insecticide,...

  12. High Modulus Biodegradable Polyurethanes for Vascular Stents: Evaluation of Accelerated in vitro Degradation and Cell Viability of Degradation Products

    PubMed Central

    Sgarioto, Melissa; Adhikari, Raju; Gunatillake, Pathiraja A.; Moore, Tim; Patterson, John; Nagel, Marie-Danielle; Malherbe, François

    2015-01-01

    We have recently reported the mechanical properties and hydrolytic degradation behavior of a series of NovoSorb™ biodegradable polyurethanes (PUs) prepared by varying the hard segment (HS) weight percentage from 60 to 100. In this study, the in vitro degradation behavior of these PUs with and without extracellular matrix (ECM) coating was investigated under accelerated hydrolytic degradation (phosphate buffer saline; PBS/70°C) conditions. The mass loss at different time intervals and the effect of aqueous degradation products on the viability and growth of human umbilical vein endothelial cells (HUVEC) were examined. The results showed that PUs with HS 80% and below completely disintegrated leaving no visual polymer residue at 18?weeks and the degradation medium turned acidic due to the accumulation of products from the soft segment (SS) degradation. As expected the PU with the lowest HS was the fastest to degrade. The accumulated degradation products, when tested undiluted, showed viability of about 40% for HUVEC cells. However, the viability was over 80% when the solution was diluted to 50% and below. The growth of HUVEC cells is similar to but not identical to that observed with tissue culture polystyrene standard (TCPS). The results from this in vitro study suggested that the PUs in the series degraded primarily due to the SS degradation and the cell viability of the accumulated acidic degradation products showed poor viability to HUVEC cells when tested undiluted, however particles released to the degradation medium showed cell viability over 80%. PMID:26000274

  13. High Modulus Biodegradable Polyurethanes for Vascular Stents: Evaluation of Accelerated in vitro Degradation and Cell Viability of Degradation Products.

    PubMed

    Sgarioto, Melissa; Adhikari, Raju; Gunatillake, Pathiraja A; Moore, Tim; Patterson, John; Nagel, Marie-Danielle; Malherbe, François

    2015-01-01

    We have recently reported the mechanical properties and hydrolytic degradation behavior of a series of NovoSorb™ biodegradable polyurethanes (PUs) prepared by varying the hard segment (HS) weight percentage from 60 to 100. In this study, the in vitro degradation behavior of these PUs with and without extracellular matrix (ECM) coating was investigated under accelerated hydrolytic degradation (phosphate buffer saline; PBS/70°C) conditions. The mass loss at different time intervals and the effect of aqueous degradation products on the viability and growth of human umbilical vein endothelial cells (HUVEC) were examined. The results showed that PUs with HS 80% and below completely disintegrated leaving no visual polymer residue at 18?weeks and the degradation medium turned acidic due to the accumulation of products from the soft segment (SS) degradation. As expected the PU with the lowest HS was the fastest to degrade. The accumulated degradation products, when tested undiluted, showed viability of about 40% for HUVEC cells. However, the viability was over 80% when the solution was diluted to 50% and below. The growth of HUVEC cells is similar to but not identical to that observed with tissue culture polystyrene standard (TCPS). The results from this in vitro study suggested that the PUs in the series degraded primarily due to the SS degradation and the cell viability of the accumulated acidic degradation products showed poor viability to HUVEC cells when tested undiluted, however particles released to the degradation medium showed cell viability over 80%. PMID:26000274

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

    PubMed

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

    2013-12-15

    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

  15. Development of a sensor for polypropylene degradation products.

    SciTech Connect

    Sawyer, Patricia Sue; Howell, Stephen Wayne; Hochrein, James Michael; Dirk, Shawn M.; Bernstein, Robert; Washburn, Cody M.; Graf, Darin C.

    2009-04-01

    This paper presents the development of a sensor to detect the oxidative and radiation induced degradation of polypropylene. Recently we have examined the use of crosslinked assemblies of nanoparticles as a chemiresistor-type sensor for the degradation products. We have developed a simple method that uses a siloxane matrix to fabricate a chemiresistor-type sensor that minimizes the swelling transduction mechanism while optimizing the change in dielectric response. These sensors were exposed with the use of a gas chromatography system to three previously identified polypropylene degradation products including 4-methyl-2-pentanone, acetone, and 2-pentanone. The limits of detection 210 ppb for 4-methy-2-pentanone, 575 ppb for 2-pentanone, and the LoD was unable to be determined for acetone due to incomplete separation from the carbon disulfide carrier.

  16. [Pesticide bioaccumulation: measurement and levels of organochlorine residues in products of vegetable origin].

    PubMed

    Diop, Y M; Diouf, A; Fall, M; Thiam, A; Ndiaye, B; Ciss, M; Ba, D

    1999-01-01

    Because of their lipophilic properties and their persistence, organochlorine pesticides residues can be accumulated in human body by consuming regularly plants products. This study consisted of the monitoring of the contamination level of pesticides residues from various plants products, in order to assess the long- term intoxication risk to which Senegalese consumer is exposed ant identify throughout these plants some indicators of atmospheric pollution. The chromatographic analysis of medicinal plants, fruits and vegetables extracts showed that they could be contaminated by organochlorine residues. About ten of these pesticides residues were found confirming that the analysed plants were really contaminated. The residues level in medicinal plants (from 0.1 to 45 micrograms/kg) were widely below the maximum allowed concentrations and were also lower than those in fruits and vegetables (from 0.1 microgram/kg to 460 micrograms/kg). Heptachlorine residues contents of tomatoes and citrus fruits were higher than FAO/WHO norms, so that, a regular monitoring of the plants products is recommended for better protection of consumers. PMID:11957276

  17. Management practices influence productivity of degraded or eroded soils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Management practices influence the productivity of eroded or degraded soil. This study investigates the influence of beef manure amendment compared with commercial fertil¬izer (urea) applied at two rates (60 and 120 lb N/a) with two tillage practices (conven¬tional tillage, CT, and no-tillage, NT). ...

  18. ISOLATION AND PURIFICATION OF CRUCIFER GLUCOSINOLATE DEGRADATION PRODUCTS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The crucifer family, Brassicaceae, is an economically important family for its many food crops. Crucifers are characterized by the presence of a group of secondary compounds called glucosinolates, which with their degradation products are primarily responsible for the characteristic aromas and flav...

  19. Production and degradation of polyhydroxyalkanoates in waste environment

    E-print Network

    - ment upon disposal. In this paper, PHA production and degradation in waste environment as well as its, bacteria accumulating polyphosphate (poly P) uptake carbon substrates and accumulate these as PHA, accumulated PHA is utilized for energy generation and for the regeneration of poly P. PHA produc- tion from

  20. 78 FR 57850 - Product Cancellation Order for Certain Pesticide Registrations

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-20

    ...Tifa International, LLC 109 Stryker Lane, Hillsborough, NJ 08844. 86363........................ Kaizen Technologies, LLC, Agent: Lighthouse Product Services, 1966 W 15th St., Suite 6, Loveland, CO...

  1. Development of an Enzyme Linked Immunosorbent Assay and an Immunochromatographic Assay for Detection of Organophosphorus Pesticides in Different Agricultural Products

    PubMed Central

    Hua, Xiude; Yang, Jifei; Wang, Limin; Fang, Qingkui; Zhang, Gaiping; Liu, Fengquan

    2012-01-01

    Objective Organophosphorus (OP) pesticides are considered hazardous substances because of their high toxicity to nontarget species and their persistence in the environment and agricultural products. Therefore, it is important to develop a rapid, sensitive, and economical method for detecting OP pesticides and their residues in food and the environment. Methods A broad, selective monoclonal antibody (MAb) for organophosphorus pesticides was produced. Based on the MAb, an enzyme linked immunosorbent assay (ELISA) and an immunochromatography assay (ICA) for detecting OP pesticides in different agricultural products were developed using a binding inhibition format on microtiter plates and a membrane strip, respectively. Results Under the optimized conditions, the IC50 values of the ELISA ranged from 3.7 to 162.2 ng mL–1 for the 8 OP pesticides. The matrix interferences of Apple, Chinese cabbage, and greengrocery were removed by 40-fold dilution, the recoveries from spiked samples ranged from 79.1% to 118.1%. The IC50 values of ICA for the 8 OP pesticides ranged from 11.8 to 470.4 ng mL?1. The matrix interference was removed from the Chinese cabbage and Apple samples with 5-fold dilution, and the interference was removed from the greengrocery samples with 20-fold dilution. The recoveries from the spiked samples ranged between 70.6 and 131.9%. The established ELISA and ICA were specific selectivity for the 8 OP pesticides. Conclusions The established ELISA is a sensitive screening method for the detection of OP pesticides, but the ELISA detection method depends on a laboratory platform and requires a relative long assay time and several steps operation. The established ICA is very useful as a screening method for the quantitative, semi-quantitative or qualitative detection of OP pesticides in agricultural products, and it has advantages over ELISA methods with regard to factors such as the testing procedure, testing time, and matrix interferences, among others. PMID:23300869

  2. Sources and Input Pathways of Glyphosate and its Degradation Product AMPA

    NASA Astrophysics Data System (ADS)

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

    2009-04-01

    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.

  3. 78 FR 24197 - Product Cancellation Order for Certain Pesticide Registrations

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-24

    ...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...

  4. 78 FR 59019 - Product Cancellation Order for Certain Pesticide Registrations

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-25

    ...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...

  5. Study on retroaldol degradation products of antibiotic oligomycin A.

    PubMed

    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

    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

  6. Production and degradation of polyhydroxyalkanoates in waste environment

    SciTech Connect

    Lee, S.Y.; Choi, J. [Korea Advanced Inst. of Science and Technology, Taejon (Korea, Republic of)] [Korea Advanced Inst. of Science and Technology, Taejon (Korea, Republic of)

    1999-06-01

    Polyhydroxyalkanoates (PHAs) are energy/carbon storage materials accumulated under unfavorable growth condition in the presence of excess carbon source. PHAs are attracting much attention as substitute for non-degradable petrochemically derived plastics because of their similar material properties to conventional plastics and complete biodegradability under natural environment upon disposal. In this paper, PHA production and degradation in waste environment as well as its role in biological phosphorus removal are reviewed. In biological phosphorus removal process, bacteria accumulating polyphosphate (poly P) uptake carbon substrates and accumulate these as PHA by utilizing energy from breaking down poly P under anaerobic conditions. In the following aerobic condition, accumulated PHA is utilized for energy generation and for the regeneration of poly P. PHA production from waste has been investigated in order to utilize abundant organic compounds in waste water. Since PHA content and PHA productivity that can be obtained are rather low, PHA production from waste product should be considered as a coupled process for reducing the amount of organic waste. PHAs can be rapidly degraded to completion in municipal anaerobic sludge by various microorganisms.

  7. 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)

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

    2012-12-01

    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.

  8. Comparative aspects of pesticide metabolism in plants and animals.

    PubMed Central

    Menn, J J

    1978-01-01

    Pesticide chemicals are an important component of modern agriculture. Through their use, plants and animals are exposed to pesticides directly and indirectly from transport through soil, water, and other environmental components. Pesticide chemicals which are absorbed by plants and animals undergo extensive biotransformation. Lipophilic compounds are converted to polar metabolites through a variety of microsomal and extramicrosomal reactions in plants and animals. Generally, biotransformations are qualitatively similar in both systems. However, there are important quantitative rate differences in metabolism which often determine the balance between activation and deactivation of a pesticide. Furthermore, there are qualitative differences in conjugative mechanisms in plants and animals. Animals through an efficient excretory system eliminate transformation products via the urine and feces. Since efficient excretory systems are absent in plants, terminal degradation products are stored as conjugates and/or derivatives which may be incorporated into the plants themselves. Metabolic transformations of selected pesticides illustrating various types of reactions in plants and animals are discussed. PMID:367763

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

    Microsoft Academic Search

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

    2007-01-01

    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

  10. 'Pesticide Use in Banana and Plantain Production and Risk Perception Among Local Actors in Talamanca, Costa Rica'

    Microsoft Academic Search

    D. A. Barraza-Ruiz; K. Jansen; Wendel de Joode van B; C. Wesseling

    2011-01-01

    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,

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

    Microsoft Academic Search

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

    2011-01-01

    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,

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

    SciTech Connect

    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

    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.

  13. 77 FR 26004 - Product Cancellation Order for Certain Pesticide Registrations

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-02

    ...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...

  14. 75 FR 82387 - Product Cancellation Order for Certain Pesticide Registrations

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-30

    ...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...

  15. Counteraction of antibiotic production and degradation stabilizes microbial communities.

    PubMed

    Kelsic, Eric D; Zhao, Jeffrey; Vetsigian, Kalin; Kishony, Roy

    2015-05-28

    A major challenge in theoretical ecology is understanding how natural microbial communities support species diversity, and in particular how antibiotic-producing, -sensitive and -resistant species coexist. While cyclic ‘rock–paper–scissors’ interactions can stabilize communities in spatial environments, coexistence in unstructured environments remains unexplained. Here, using simulations and analytical models, we show that the opposing actions of antibiotic production and degradation enable coexistence even in well-mixed environments. Coexistence depends on three-way interactions in which an antibiotic-degrading species attenuates the inhibitory interactions between two other species. These interactions enable coexistence that is robust to substantial differences in inherent species growth rates and to invasion by ‘cheating’ species that cease to produce or degrade antibiotics. At least two antibiotics are required for stability, with greater numbers of antibiotics enabling more complex communities and diverse dynamic behaviours ranging from stable fixed points to limit cycles and chaos. Together, these results show how multi-species antibiotic interactions can generate ecological stability in both spatially structured and mixed microbial communities, suggesting strategies for engineering synthetic ecosystems and highlighting the importance of toxin production and degradation for microbial biodiversity. PMID:25992546

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

    PubMed

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

    2014-02-01

    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

  17. 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

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

    2007-01-01

    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).

  18. Routine low-level monitoring of polar pesticides and pesticide degradates by HPLC/ESI-MS: Evaluating long-term performance

    USGS Publications Warehouse

    Furlong, E.T.; Martin, J.D.; Werner, S.L.; Gates, P.M.

    2002-01-01

    The sensitivity and selective determination of polar pesticides were analyzed using high-performance liquid chromatography/electrospray ionization-mass spectrometry (HPLC/ESI-MS). The effects of multiple operators and instruments on method performance were evaluated using 440 pairs of fortified reagent-water and blank reagent-water samples. The influence of varying environmental matrices on recovery and precision were also analyzed using 200 fortified ambient water samples and duplicate ambient water samples. The results show that compound stability in filtered water was matrix-, chemical class- and compound-dependent which ranged from 1 day to 2 weeks.

  19. Surface detection of chemical warfare agent simulants and degradation products

    Microsoft Academic Search

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

    2005-01-01

    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

  20. 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 ...

  1. Bees and Pesticides

    Microsoft Academic Search

    Róbert Chlebo

    2006-01-01

    Honey bees (Apis mellifera L.) are the main pollinating agents for numerous plants and fruit trees and hence, play a key role in agriculture and more generally in the maintenance of ecological biodiversity. They are mostly affected farm animals by pesticides. Indeed, pesticides work in two ways to reduce bee populations. First, many pesticides used in crop production are highly

  2. Neonicotinoid pesticide reduces bumble bee colony growth and queen production.

    PubMed

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

    2012-04-20

    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

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

    PubMed

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

    2011-07-01

    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

  4. Radiolytic gas production in the alpha particle degradation of plastics

    SciTech Connect

    Reed, D.T.; Hoh, J.; Emery, J. (Argonne National Lab., IL (United States)); Hobbs, D. (Westinghouse Savannah River Co., Aiken, SC (United States))

    1992-01-01

    Net gas generation due to alpha particle irradiation of polyethylene and polyvinyl chloride was investigated. Experiments were performed in an air environment at 30, 60, and 100{degree}C. The predominant radiolytic degradation products of polyethylene were hydrogen and carbon dioxide with a wide variety of trace organic species noted. Irradiation of polyvinyl chloride resulted in the formation of HCl in addition to the products observed for polyethylene. For both plastic materials, a strong enhancement of net yields was noted at 100{degree}C.

  5. Radiolytic gas production in the alpha particle degradation of plastics

    SciTech Connect

    Reed, D.T.; Hoh, J.; Emery, J. [Argonne National Lab., IL (United States); Hobbs, D. [Westinghouse Savannah River Co., Aiken, SC (United States)

    1992-05-01

    Net gas generation due to alpha particle irradiation of polyethylene and polyvinyl chloride was investigated. Experiments were performed in an air environment at 30, 60, and 100{degree}C. The predominant radiolytic degradation products of polyethylene were hydrogen and carbon dioxide with a wide variety of trace organic species noted. Irradiation of polyvinyl chloride resulted in the formation of HCl in addition to the products observed for polyethylene. For both plastic materials, a strong enhancement of net yields was noted at 100{degree}C.

  6. Imazalil Degradation upon Applying Ozone—Transformation Products, Kinetics, and Toxicity of Treated Aqueous Solutions

    Microsoft Academic Search

    Aziza K. Genena; Danielle B. Luiz; Wilhelm Gebhardt; Regina F. P. M. Moreira; Humberto J. José; Horst Fr. Schröder

    2011-01-01

    The elimination of the pesticide imazalil (IMZ) spiked into ultrapure water as well as into wastewater applying ozone (O3) and the identification of transformation products was investigated. O3 under hydroxyl radical suppression conditions reacted rapidly with the aliphatic double bond or the imidazole ring in IMZ, yielding several transformation products by partial oxidation. The structures of four oxidation products not

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

    PubMed

    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

    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

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

    PubMed Central

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

    2013-01-01

    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

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

    PubMed

    Bajwa, Usha; Sandhu, Kulwant Singh

    2014-02-01

    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

  10. Liquid chromatography tandem mass spectrometric studies of indinavir sulphate and its forced degradation products.

    PubMed

    Rao, R Nageswara; Vali, R Mastan; Raju, S Satyanarayana

    2013-02-23

    Indinavir sulphate was subjected to forced degradation under hydrolysis (acidic, basic and neutral), oxidation, photolysis and thermal stress as prescribed by ICH guidelines. It was degraded under acidic, basic, neutral and oxidative stress conditions, while it was stable under other conditions. After degradation total eight degradation products were formed. The degradation products were identified and their separation was accomplished on Waters XTerra(®) C(18) column (250 mm × 4.6mm i.d., 5 ?m) using 20mM ammonium actate:acetonitrile as (50:50, v/v) mobile phase in an isocratic elution mode by LC. The method was extended to LC-MS/MS for characterization of the degradation products and the fragmentation pathways were proposed. The proposed structures of degradation products were also confirmed by HRMS studies. No previous reports were found in the literature regarding the characterization of degradation products of indinavir sulphate. PMID:23245240

  11. Reaction pathways in the electrochemical degradation of thiocarbamate herbicides in NaCl solution

    Microsoft Academic Search

    FERENC MOGYORÓDY

    2006-01-01

    We have identified the intermediates and end products which are formed during the electrolytic degradation of thiocarbamate pesticides in aqueous NaCl solutions and investigated how the intermediate and end product volumes and ratios depend on reaction conditions. Further, we have defined both the reaction pathways leading to intermediate and end product formation and the methods affecting this process. The degradation

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

    NASA Astrophysics Data System (ADS)

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

    2005-12-01

    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.

  13. Management technologies can reduce the environmental risk of pesticides in agricultural production

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pesticide use in agriculture, the potential risk posed by pesticides when they are transported beyond the intended target, and their effects on human and environmental health have been of public concern for many years. We utilized 5 years of field data, quantifying pesticide transport with runoff fr...

  14. Monitoring land degradation in Southern Africa based on net primary productivity

    Microsoft Academic Search

    K. J. Wessels; S. D. Prince; J. Small

    2003-01-01

    Land degradation involves conditions of reduced net primary production (NPP). Our objective was to develop and evaluate a land degradation monitoring approach that is based on NPP. NPP was modeled using the Global Production Efficiency Model (GLO-PEM) and 1km AVHRR data. Degraded areas in the Northern Province of South Africa were successfully detected using NPP, Rain Use Efficiency (RUE) and

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

    PubMed

    Hossaini, Hiwa; Moussavi, Gholamreza; Farrokhi, Mehrdad

    2014-08-01

    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

  16. The Effect of Soil Inoculation with Microbial Pesticide Destructors on Plant Growth and Development

    Microsoft Academic Search

    T. O. Lisina; N. G. Garan'kina; Yu. V. Kruglov

    2001-01-01

    Soil inoculation with liquid cultures of Bacillus megaterium501 and Exophiala nigrumA-29 capable of degrading several organophosphorus pesticides accelerated the growth and development of experimental plants, the formation of their generative organs, and improved their productivity. This was particularly observed under stress plant growth conditions on phytotoxic peach substrates. The microorganisms inoculated can probably degrade the phytotoxins present in soils, thereby

  17. HPLC analysis of pheomelanin degradation products in human urine.

    PubMed

    Takasaki, Akihiko; Nezirevi?, Dzeneta; Arstrand, Kerstin; Wakamatsu, Kazumasa; Ito, Shosuke; Kågedal, Bertil

    2003-10-01

    A sensitive and specific high performance liquid chromatography (HPLC) method was developed to quantify 4-amino-3-hydroxyphenylalanine (4-AHP) and 3-amino-4-hydroxyphenylalanine (3-AHP) in urine. In degradation studies of melanin pigment, 4-AHP and 3-AHP are derived from benzothiazine units of pheomelanin and pheomelanin-related metabolites such as trichochromes. 5-S-Cysteinyldopa-derived benzothiazine products give 4-AHP while 2-S-cysteinyldopa-derived benzothiazine products give 3-AHP. 3-AHP is also derived from nitrotyrosine formed by nitration of tyrosine with reactive nitrogen species. For this reason, the influence of this biological process on the amount of 3-AHP found in biological material have been investigated. The method is based on hydriodic acid hydrolysis of the melanin polymer and reversed-phase HPLC with electrochemical detection of the degradation products 4-AHP and 3-AHP. The mobile phase consists of 25 mM ammonium acetate and sodium octanesulfonate as an ion-pairing reagent. The 4-AHP and 3-AHP peaks were well separated and the detector response was linear within the range 0-2 ng injected for both compounds. With the developed chromatographic system, 4-AHP and 3-AHP showed good separation in the biological samples. There was a strong correlation between 4-AHP and 3-AHP in the urine of 50 malignant melanoma patients and two healthy subjects (R0.977). The two compounds were also strongly correlated with 5-S-cysteinyldopa in urine, the correlation coefficients being 0.862 and 0.907, respectively. The method described is sensitive enough for analysis of pheomelanin in urine and in several other biological samples. The results indicate that 3-AHP in urine is not influenced by excreted 3-nitrotyrosine and the data indicate that pheomelanins are excreted in the urine of melanoma patients. PMID:12950724

  18. Magnesium degradation products: effects on tissue and human metabolism.

    PubMed

    Seitz, J-M; Eifler, R; Bach, Fr-W; Maier, H J

    2014-10-01

    Owing to their mechanical properties, metallic materials present a promising solution in the field of resorbable implants. The magnesium metabolism in humans differs depending on its introduction. The natural, oral administration of magnesium via, for example, food, essentially leads to an intracellular enrichment of Mg(2+) . In contrast, introducing magnesium-rich substances or implants into the tissue results in a different decomposition behavior. Here, exposing magnesium to artificial body electrolytes resulted in the formation of the following products: magnesium hydroxide, magnesium oxide, and magnesium chloride, as well as calcium and magnesium apatites. Moreover, it can be assumed that Mg(2+) , OH(-) ions, and gaseous hydrogen are also present and result from the reaction for magnesium in an aqueous environment. With the aid of physiological metabolic processes, the organism succeeds in either excreting the above mentioned products or integrating them into the natural metabolic process. Only a burst release of these products is to be considered a problem. A multitude of general tissue effects and responses from the Mg's degradation products is considered within this review, which is not targeting specific implant classes. Furthermore, common alloying elements of magnesium and their hazardous potential in vivo are taken into account. PMID:24222399

  19. Enhancing the Promiscuous Phosphotriesterase Activity of a Thermostable Lactonase (GkaP) for the Efficient Degradation of Organophosphate Pesticides

    PubMed Central

    Zhang, Yu; An, Jiao; Ye, Wei; Yang, Guangyu; Qian, Zhi-Gang; Chen, Hai-Feng; Cui, Li

    2012-01-01

    The phosphotriesterase-like lactonase (PLL) enzymes in the amidohydrolase superfamily hydrolyze various lactones and exhibit latent phosphotriesterase activities. These enzymes serve as attractive templates for in vitro evolution of neurotoxic organophosphates (OPs) with hydrolytic capabilities that can be used as bioremediation tools. Here, a thermostable PLL from Geobacillus kaustophilus HTA426 (GkaP) was targeted for joint laboratory evolution with the aim of enhancing its catalytic efficiency against OP pesticides. By a combination of site saturation mutagenesis and whole-gene error-prone PCR approaches, several improved variants were isolated. The most active variant, 26A8C, accumulated eight amino acid substitutions and demonstrated a 232-fold improvement over the wild-type enzyme in reactivity (kcat/Km) for the OP pesticide ethyl-paraoxon. Concomitantly, this variant showed a 767-fold decrease in lactonase activity with ?-decanolactone, imparting a specificity switch of 1.8 × 105-fold. 26A8C also exhibited high hydrolytic activities (19- to 497-fold) for several OP pesticides, including parathion, diazinon, and chlorpyrifos. Analysis of the mutagenesis sites on the GkaP structure revealed that most mutations are located in loop 8, which determines substrate specificity in the amidohydrolase superfamily. Molecular dynamics simulation shed light on why 26A8C lost its native lactonase activity and improved the promiscuous phosphotriesterase activity. These results permit us to obtain further insights into the divergent evolution of promiscuous enzymes and suggest that laboratory evolution of GkaP may lead to potential biological solutions for the efficient decontamination of neurotoxic OP compounds. PMID:22798358

  20. Micronuclei and pesticide exposure.

    PubMed

    Bolognesi, Claudia; Creus, Amadeu; Ostrosky-Wegman, Patricia; Marcos, Ricard

    2011-01-01

    Micronucleus (MN) is a biomarker widely used in biomonitoring studies carried out to determine the genetic risk associated to pesticide exposure. Many in vitro and in vivo studies, as well as epidemiological approaches, have demonstrated the ability of certain chemical pesticides to produce genetic effects including cancer and other chronic pathologies in humans; thus, biomonitoring studies have been carried out to characterise the genetic risk associated to pesticide exposure. It must be noted that 'pesticide exposure' is a broad term covering complex mixtures of chemicals and many variables that can reduce or potentiate their risk. In addition, there are large differences in pesticides used in the different parts of the world. Although pesticides constitute a wide group of environmental pollutants, the main focus on their risk has been addressed to people using pesticides in their working places, at the chemical industry or in the crop fields. Here, we present a brief review of biomonitoring studies carried out in people occupationally exposed to pesticides and that use MN in lymphocytes or buccal cells as a target to determine the induction of genotoxic damage. Thus, people working in the chemical industry producing pesticides, people spraying pesticides and people dedicated to floriculture or agricultural works in general are the subject of specific sections. MN is a valuable genotoxic end point when clear exposure conditions exist like in pesticide production workers; nevertheless, better study designs are needed to overcome the uncertainty in exposure, genetic susceptibility and statistical power in the studies of sprayers and floriculture or agricultural workers. PMID:21164178

  1. Toxicology of atmospheric degradation products of selected hydrochlorofluorocarbons

    NASA Technical Reports Server (NTRS)

    Kaminsky, Laurence S.

    1990-01-01

    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.

  2. Adsorption of Pesticides and Their Biodegraded Products on Clay Minerals and Soils

    Microsoft Academic Search

    Yuichi Fushiwaki; Kohei Uranob

    2001-01-01

    Adsorption isotherms of 10 pesticides and their biodegradation intermediates on clay minerals and soils were investigated to predict the fate of pesticides in the environment. The adsorption isotherms were expressed by the Freundlich isotherm equation. Penta- chloronitrobenzene, 2,4,6-trichlorophenyl-4'-nitro- phenylether, and various intermediates were highly adsorbed on soils, although isoprothiolane was only slightly adsorbed. The adsorbabilities of pesticides on ando soil,

  3. Identifying high production, low production and degraded rangelands in Senegal with normalized difference vegetation index data

    USGS Publications Warehouse

    Tappan, G. Gray; Wood, Lynette; Moore, Donald G.

    1993-01-01

    Seasonal herbaceous vegetation production on Senegal's native rangelands exhibits high spatial and temporal variability. This variability can be monitored using normalized difference vegetation index (NDVI) data computed from 1-km resolution Advanced Very High Resolution Radiometer (AVHRR) image data. Although annual fluctuations in rainfall account for some of the variability, numerous long-term production patterns are evident in the AVHRR time-series data. Different n productivity reflect variations in the region's climate, topography, soils, and land use. Areas of overgrazing and intensive cultivation have caused long-term soil and vegetation degradation. Rangelands of high and low productivity, and degraded rangelands were identified using NDVI. Time-series image data from 1987 though 1992 were used to map relative rangeland productivity. The results were compared to detailed resource maps on soils, vegetation and land use. Much of the variation in rangeland productivity correlated well to the known distribution of resources. The study developed an approach that identified a number of areas of degraded soils and low vegetation production.

  4. Anaerobic degradation of renewable biomass for production of methane

    SciTech Connect

    Rajoka, M.I.; Tabassum, R.; Malik, K.A. [National Institute for Biotechnology and Genetic Engineering, Faisalabad (Pakistan)

    1996-12-31

    Anaerobic degradation of renewable biomass namely kallar grass (KG) (Leptochloafusca L. Kunth), Atriplex sp, wheat straw, cotton stalk, cotton lint and molasses was carried out at 37{degrees}C in a 15 litre fermentor, using laboratory enriched co-culture of fermentative, acetogenic and methanogenic organisms. Maximum reduction of volatile solids (VS) was from causticized KG, and cotton lint, followed by causticized wheat straw and Atriplex sp. followed by causticized wheat straw and Atriplex sp. Maximum production of methane was obtained from NaOH-pretreated KG with a process product yield (Y{sub p/s}) of 0.9 m{sup 3}/kg VS with a volumetric productivity (Q{sub p}) of 4.24 L/day after 19 days of fermentation. Maximum methane content in the gas mixture was 96% with average of 78.6{+-}21.6. The Y{sub p/s} in 1000 litre digestor was 0.7 m{sup 3}/kg VS from a 3% suspension of uncaustisized kallar grass.

  5. Photocatalytic degradation of malathion in aqueous solution using an Au–Pd–TiO 2 nanotube film

    Microsoft Academic Search

    Hongbin Yu; Xinhong Wang; Hongwei Sun; Mingxin Huo

    2010-01-01

    The extensive use of pesticides has promoted the agricultural production, but a series of subsequent environmental issues have drawn the concern of governments and people worldwide, such as groundwater and surface water pollutions. In order to remove these pollutants, photocatalysis has emerged as a powerful method. In this paper, the photocatalytic degradation of an organophosphorus pesticide malathion was investigated using

  6. Degradation of methylparathion in aqueous solution by electrochemical oxidation.

    PubMed

    Vlyssides, Apostolos; Barampouti, Elli Maria; Mai, Sofia; Arapoglou, Dimitris; Kotronarou, Anastasia

    2004-11-15

    The electrochemical degradation of methylparathion has been investigated by using Ti/Pt as anode, Stainless Steel 304 as cathode, and sodium chloride as electrolyte. The pesticide is rapidly degraded, but full mineralization is not observed. Degradation products have been monitored through gas chromatography and mass spectrometry, and the overall degradation process has been monitored through dissolved and particulate organic carbon, sulfur, and phosphorus measurements. Several intermediates have been identified, and oxalic, formic, and acetic acids as well as tetraphosphorus trisulfide have been recognized as final products of the degradation process. A proposed mechanism of the process is presented. PMID:15573616

  7. Life cycle toxicity assessment of pesticides used in integrated and organic production of oranges in the Comunidad Valenciana, Spain.

    PubMed

    Juraske, Ronnie; Sanjuán, Neus

    2011-02-01

    The relative impacts of 25 pesticides including acaricides, fungicides, herbicides, insecticides, and post-harvest fungicides, used in the production of oranges in Spain were assessed with current life cycle impact assessment (LCIA) tools. Chemical specific concentrations were combined with pesticide emission data and information on chemical toxicity to assess human toxicity and freshwater ecotoxicity impacts. As a case study, the relative impacts of two orange production systems in the region of Valencia, integrated pest management (IP) and organic production (OP), were assessed. The evaluation of active ingredients showed that on average acaricides have the highest human toxicity impact scores, while for freshwater ecotoxicity insecticides show the highest impact. In both impact categories the lowest impact scores were calculated for herbicides. In the production of 1 kg of orange fruits, where several kinds of pesticides are combined, results show that post-harvest fungicides can contribute more than 95% to the aggregate human toxicity impacts. More than 85% of aquatic ecotoxicity is generated by fungicides applied before harvest. The potential to reduce impacts on freshwater ecosystems is seven orders of magnitude, while impacts on human health can be reduced by two orders of magnitude. Hence, this stresses the importance of a careful pre-selection of active ingredients. In both impact categories, organic production represents the least toxic pest-control method. PMID:21075421

  8. Assessment of risk to public health posed by persistent organochlorine pesticide residues in milk and milk products in Mumbai, India.

    PubMed

    Pandit, G G; Sahu, S K

    2002-02-01

    The risk posed by the presence of organochlorine pesticides in milk and milk products was estimated for the population of Mumbai. To determine the levels of organochlorine pesticides in milk and milk products, a monitoring study was carried out in and around Mumbai City. 520 samples of milk and milk products of different brands were considered in this study. A survey was also conducted to determine the mean daily consumption of milk and milk products by different age groups and this data was used to evaluate the daily exposure to the public. Non-cancer effects were evaluated by comparing the predicted exposure distributions to the published guidance values. For chemicals identified as potential human carcinogens, cancer risk was evaluated using standard methodology. The majority of the chlorinated pesticides identified in the milk and milk product samples studied were found to be at levels which do not pose unacceptable risks to the public, with the exception of alpha-HCH. The cancer risk estimated for this chemical slightly exceeds the US EPA guidance value. PMID:11871703

  9. Pesticide flow analysis to assess human exposure in greenhouse flower production in Colombia.

    PubMed

    Lesmes-Fabian, Camilo; Binder, Claudia R

    2013-04-01

    Human exposure assessment tools represent a means for understanding human exposure to pesticides in agricultural activities and managing possible health risks. This paper presents a pesticide flow analysis modeling approach developed to assess human exposure to pesticide use in greenhouse flower crops in Colombia, focusing on dermal and inhalation exposure. This approach is based on the material flow analysis methodology. The transfer coefficients were obtained using the whole body dosimetry method for dermal exposure and the button personal inhalable aerosol sampler for inhalation exposure, using the tracer uranine as a pesticide surrogate. The case study was a greenhouse rose farm in the Bogota Plateau in Colombia. The approach was applied to estimate the exposure to pesticides such as mancozeb, carbendazim, propamocarb hydrochloride, fosetyl, carboxin, thiram, dimethomorph and mandipropamide. We found dermal absorption estimations close to the AOEL reference values for the pesticides carbendazim, mancozeb, thiram and mandipropamide during the study period. In addition, high values of dermal exposure were found on the forearms, hands, chest and legs of study participants, indicating weaknesses in the overlapping areas of the personal protective equipment parts. These results show how the material flow analysis methodology can be applied in the field of human exposure for early recognition of the dispersion of pesticides and support the development of measures to improve operational safety during pesticide management. Furthermore, the model makes it possible to identify the status quo of the health risk faced by workers in the study area. PMID:23528812

  10. Pesticide Flow Analysis to Assess Human Exposure in Greenhouse Flower Production in Colombia

    PubMed Central

    Lesmes-Fabian, Camilo; Binder, Claudia R.

    2013-01-01

    Human exposure assessment tools represent a means for understanding human exposure to pesticides in agricultural activities and managing possible health risks. This paper presents a pesticide flow analysis modeling approach developed to assess human exposure to pesticide use in greenhouse flower crops in Colombia, focusing on dermal and inhalation exposure. This approach is based on the material flow analysis methodology. The transfer coefficients were obtained using the whole body dosimetry method for dermal exposure and the button personal inhalable aerosol sampler for inhalation exposure, using the tracer uranine as a pesticide surrogate. The case study was a greenhouse rose farm in the Bogota Plateau in Colombia. The approach was applied to estimate the exposure to pesticides such as mancozeb, carbendazim, propamocarb hydrochloride, fosetyl, carboxin, thiram, dimethomorph and mandipropamide. We found dermal absorption estimations close to the AOEL reference values for the pesticides carbendazim, mancozeb, thiram and mandipropamide during the study period. In addition, high values of dermal exposure were found on the forearms, hands, chest and legs of study participants, indicating weaknesses in the overlapping areas of the personal protective equipment parts. These results show how the material flow analysis methodology can be applied in the field of human exposure for early recognition of the dispersion of pesticides and support the development of measures to improve operational safety during pesticide management. Furthermore, the model makes it possible to identify the status quo of the health risk faced by workers in the study area. PMID:23528812

  11. Determination of pharmaceuticals, personal care products, and pesticides in surface and treated waters: method development and survey.

    PubMed

    Caldas, Sergiane Souza; Bolzan, Cátia Marian; Guilherme, Juliana Rocha; Silveira, Maria Angelis Kisner; Escarrone, Ana Laura Venquiaruti; Primel, Ednei Gilberto

    2013-08-01

    Water is fundamental to the existence of life since it is essential to a series of activities, such as agriculture, power generation, and public and industrial supplies. The residual water generated by these activities is released into the environment, reaches the water systems, and becomes a potential risk to nontarget organisms. This paper reports the development and validation of a quantitative method, based on solid-phase extraction and liquid chromatography tandem mass spectrometry, for the simultaneous analysis of 18 pharmaceuticals and personal care products (PPCPs) and 33 pesticides in surface and drinking waters. The accuracy of the method was determined by calculating the recoveries, which ranged from 70 to 120 % for most pesticides and PPCPs, whereas limits of quantification ranged from 0.8 to 40 ng/L. After the validation step, the method was applied to drinking and surface waters. Pesticides and PPCPs were found in concentrations lower than 135.5 ng/L. The evaluation of different water sources with regard to contamination by pesticides and PPCPs has been quite poor in southern Brazil. PMID:23539208

  12. Comparison of thermal degradation products from real municipal waste plastic and model mixed plastics

    Microsoft Academic Search

    Thallada Bhaskar; Kazuya Murai; Jun Kaneko; Kenji Hamano; Toshiaki Kusaba; Akinori Muto; Yusaku Sakata

    2003-01-01

    The thermal degradation of real municipal waste plastic (MWP) obtained from Sapporo, Japan and model mixed plastics was carried out at 430°C in atmospheric pressure by batch operation. The chlorinated hydrocarbons found in PE\\/PP\\/PS\\/PVC [poly(ethylene)\\/poly(propylene)\\/poly(styrene)\\/poly(vinyl chloride)] degradation liquid products were also observed in PE\\/PP\\/PS\\/PVC\\/PET (poly(ethylene terephalate)) and MWP degradation liquid products. The presence of PET in MWP produced the additional

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

    USGS Publications Warehouse

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

    2001-01-01

    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.

  14. Levels of organochlorine pesticides in crops and related products from Vojvodina, Serbia: estimated dietary intake.

    PubMed

    Skrbi?, B; Predojevi?, Z

    2008-05-01

    Levels of 16 organochlorine pesticides (OCPs) were investigated in 39 composite samples of agricultural crops, related by-products, and foodstuffs collected in Vojvodina, Serbia, in 2002 through 2004. After extraction and cleanup, OCPs were determined by capillary gas chromatography using electron-capture detection. The highest mean level of 0.971 ng/g whole weight (ww) was found for alpha-HCH in wheat flour samples. OCPs levels were well lower than the respective maximum residue limits set by current European and Serbian regulations. Mean OCP levels were low (<1 ng/g ww) for all sample types. The most frequently determined residue was 4,4'-DDT (identified in 76.9% of all samples analyzed), followed by gamma-HCH (66.7%), beta-HCH (48.7%), and endosulfan II (41.0%). OCP levels were compared with data from other international surveys. Calculated daily intakes of OCPs by way of consumption of the crop products included in this study according to data of the Serbian National Institute for Statistics were compared with the acceptable daily intakes established by the Food and Agriculture Organization/World Health Organization. The average level of contamination of the Vojvodina diet was believed to be harmless regarding the studied food commodities. PMID:18197356

  15. Transfer of pesticides and copper in a stormwater wetland receiving contaminated runoff from a vineyard catchment

    NASA Astrophysics Data System (ADS)

    Maillard, E.; Babcsanyi, I.; Payraudeau, S.; Imfeld, G.

    2012-04-01

    Wetlands can collect contaminated runoff from urban and agricultural catchments, and have intrinsic physical, chemical and biological processes useful for mitigating pesticides. However, knowledge about the ability of wetlands to mitigate pesticide mixtures in runoff is currently very limited. Our results show that stormwater wetlands that primarily serve for flood protection can also be effective tools for reducing concentrations and loads of runoff-related pesticides. Concentrations and loads of 20 pesticides and degradation products, as well as copper were continuously recorded during the period of pesticide application (April to September 2009, 2010 and 2011) at the inlet, the outlet and in sediments of a stormwater wetland that collects runoff from a vineyard catchment. Removal rates of dissolved loads ranged from 39% (simazine) to 100% (cymoxanil, gluphosinate, kresoxim methyl and terbuthylazine). Dimethomorph, diuron, glyphosate and metalaxyl were more efficiently removed in spring than in summer. The calculation of sedimentation rates from discharge measurements and total suspended solids (TSS) values revealed that the wetland retained more than 77% of the input mass of suspended solids, underscoring the capability of the wetland to trap pesticide-laden particles. Only flufenoxuron was frequently detected in the wetland sediments. An inter-annual comparison showed that changes in the removal of aminomethylphosphonic acid (AMPA, a degradation product of glyphosate), isoxaben or simazine can be attributed mainly to the larger vegetation cover in 2010 compared to 2009. More than 80% of the copper load entering the wetland was retained in the sediments and the plants. Our results demonstrate that stormwater wetlands can efficiently remove pesticide mixtures and copper in agricultural runoff during critical periods of pesticide application. Nevertheless, fluctuations in the runoff regime, as well as the vegetation and hydrochemical characteristics affect the removal rate of individual pesticides and copper in stormwater wetlands. Therefore the use of stormwater wetlands as a management practice targeting pesticide and copper mitigation should not be conceived as a unique solution to treat pesticide runoff.

  16. The Bioutilization of Thiodiglycol (a Detoxication Product of Mustard Gas): Isolation of Degrading Strains and Investigation of Degradation Conditions

    Microsoft Academic Search

    E. B. Tikhonova; I. T. Ermakova; A. V. Slepen'kin; K. I. Kashparov; I. I. Starovoitov; A. M. Boronin

    2002-01-01

    The Alcaligenes xylosoxydans subsp.denitrificans strain TD1 capable of degrading thiodiglycol (TDG), a product of mustard gas hydrolysis, was isolated from soil contaminated with breakdown products of this chemical warfare agent. The selected stable variant of TD1 (strain TD2) can grow on TDG with a lag phase of 4–8 h and a specific growth rate of 0.04–0.045 h–1. Optimal conditions for

  17. Thermal degradation of polytetrafluoroethylene in flowing helium atmosphere II. Product distribution and reaction mechanism

    Microsoft Academic Search

    Hae Sang Jun; Kyung Nam Kim; Kun You Park; Seong Ihl Woo

    1995-01-01

    The thermal degradation of polytetrafluoroethylene was studied in the helium flowing atmosphere and the temperature range\\u000a 510–600?C. The products of the thermal degradation of polytetrafluoroethylene were analyzed by an on-line gas Chromatograph\\u000a and the product distribution was obtained. The products consist of tetrafluoroethylene (TFE), perfluoropropene (PFP) and cyclic-perfluorobutane\\u000a (c-PFB). Under most conditions the main product was TFE. The c-PFB was

  18. Fast in vitro hydrolytic degradation of polyester urethane acrylate biomaterials: structure elucidation, separation and quantification of degradation products.

    PubMed

    Ghaffar, A; Verschuren, P G; Geenevasen, J A J; Handels, T; Berard, J; Plum, B; Dias, A A; Schoenmakers, P J; van der Wal, Sj

    2011-01-21

    Synthetic biomaterials have evoked extensive interest for applications in the field of health care. Prior to administration to the body a quantitative study is necessary to evaluate their composition. An in vitro method was developed for the quick hydrolytic degradation of poly-2-hydroxyethyl methacrylate (pHEMA), poly(lactide-co-glycolide50/50)1550-diol (PLGA(50:50)(1550)-diol), PLGA(50:50)(1550)-diol(HEMA)(2) and PLGA(50:50)(1550)-diol(etLDI-HEMA)(2) containing ethyl ester lysine diisocyanate (etLDI) linkers using a microwave instrument. Hydrolysis time and temperature were optimized while monitoring the degree of hydrolysis by (1)H NMR spectroscopy. Complete hydrolytic degradation was achieved at 120°C and 3 bar pressure after 24 h. Chemical structure elucidations of the degradation products were carried out using (1)H and (13)C NMR spectroscopy. The molecular weight (MW) of the polymethacrylic backbone was estimated via size-exclusion chromatography coupled to refractive index detection (SEC-dRI). A bimodal MW distribution was found experimentally, also in the pHEMA starting material. The number average molecular weights (M(n)) of the PLGA-links (PLGA(50:50)(1550)-diol) were calculated by high pressure liquid chromatography-time-of-flight mass spectrometry (HPLC-TOF-MS) and (1)H NMR. The amounts of the high and low MW degradation products were determined by SEC-dRI and, HPLC-TOF-MS, respectively. The main hydrolysis products poly (methacrylic acid) (PMAA), ethylene glycol (EG), diethylene glycol (DEG), lactic acid (LA), glycolic acid (GA) and lysine were recovered almost quantitatively. The current method leads to the complete hydrolytic degradation of these materials and will be helpful to study the degradation behavior of these novel cross-linked polymeric biomaterials. PMID:21167489

  19. Gamma radiolytic degradation of fluoranthene and monitoring of radiolytic products using GC MS and HPLC

    NASA Astrophysics Data System (ADS)

    Bilal Butt, S.; Qureshi, Rashid Nazir

    2008-06-01

    Removal of priority pollutant fluoranthene in methanol by gamma-irradiation under varied conditions has been optimized. The influence of applied dose and dose rate on the degradation of fluoranthene under nitrogen has been investigated. The preliminary radiolytic degradation efficiency has been monitored by spectrophotometry. HPLC and GC-MS have been used to study the nature of degradation pattern. It is found that four main degradation products are formed and detected by HPLC. Different reversed phase columns have been used for the separation of degraded products under optimum chromatographic conditions. For 2 kGy dose ?80% fluoranthene has been degraded at dose rate 200 Gy/h. However, a dose of 370 Gy/h was more effective and it produces for less degradation products. Radiolytic degraded fluoranthene was also analyzed to detect various degradation products using GC-MS. It was proposed that major products were hydrocarbons and methoxy group containing organic compounds after comparing their mass spectra with the installed NIST mass spectral library.

  20. Pesticide\\/Environmental Exposures and Parkinson's Disease in East Texas

    Microsoft Academic Search

    Amanpreet S. Dhillon; G. Lester Tarbutton; Jeffrey L. Levin; George M. Plotkin; Larry K. Lowry; J. Torey Nalbone; Sara Shepherd

    2008-01-01

    Epidemiological evidence suggests that pesticides and other environmental exposures may have a role in the etiology of idiopathic Parkinson's disease (PD). However, there is little human data on risk associated with specific pesticide products, including organic pesticides such as rotenone with PD. Using a case-control design, this study examined self-reports of exposure to pesticide products, organic pesticides such as rotenone,

  1. 76 FR 41178 - Pesticides; Policies Concerning Products Containing Nanoscale Materials; Opportunity for Public...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-13

    ...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...

  2. Production of Trichoderma strains with pesticide-polyresistance by mutagenesis and protoplast fusion

    Microsoft Academic Search

    Lóránt Hatvani; László Manczinger; László Kredics; András Szekeres; Zsuzsanna Antal; Csaba Vágvölgyi

    2006-01-01

    The sensitivity of two cold-tolerant Trichoderma strains belonging to the species T. harzianum and T.?atroviride was determined to a series of pesticides widely used in agriculture. From the 16 pesticides tested, seven fungicides: copper sulfate, carbendazim, mancozeb, tebuconazole, imazalil, captan and thiram inhibited colony growth of the test strains significantly with minimal inhibitory concentrations of 300, 0.4, 50, 100, 100,

  3. Interaction of structurally diverse pesticides with the human MDR1 gene product P-glycoprotein.

    PubMed

    Bain, L J; LeBlanc, G A

    1996-11-01

    P-glycoprotein (P-gp) is a 170-kDa membrane-bound glycoprotein shown to efflux a wide variety of chemicals, such as chemotherapeutic agents and carcinogens. Experiments were conducted using B16/F10 murine melanoma cells transfected with the human MDR1 gene (B16/hMDR1 cells), which codes for P-gp, to determine whether this transporter may contribute to the cellular efflux of some pesticides. Thirty-eight pesticides representing several classes of compounds were evaluated for their potential to bind to P-gp, as measured by the inhibition of efflux of the P-gp substrate doxorubicin. Carbamate and pyrethroid insecticides exhibited little interaction with P-gp, while many of the organophosphorus and organochlorine pesticides significantly inhibited the efflux of doxorubicin. Pesticides that significantly inhibited the efflux of doxorubicin were then assessed for P-gp-mediated efflux. One pesticide, endosulfan, exhibited slight though significant transport mediated by P-gp. Competition experiments performed with the P-glycoprotein ligand [3H]azidopine demonstrated that the P-gp inhibitory pesticides bound to P-gp. Both lipophilicity and molecular mass were major physical/chemical determinants in dictating pesticide binding to P-gp, with optimum binding occurring with compounds having a log Kow value of 3.6-4.5 and a molecular weight of 391-490 Da. The transport substrate endosulfan possessed optimal binding characteristics. These results demonstrated that many pesticides are capable of binding to P-gp; however, binding does not infer transport. PMID:8917702

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

    PubMed Central

    Wei, Guo-dong; Wen, Xue-sen

    2014-01-01

    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. PMID:24914291

  5. Genetically engineered pesticide biodegradation by Gliocladium virens 

    E-print Network

    Supak, Janet Marie

    1990-01-01

    was similar to that isolated by Audus. Biological breakdown of pesticides continues to be studied, Using experiments similar to Brown and Nitchell (8), Megharaj, et al. (28) found that monocrotophos was degraded in nonautoclaved soil but This thesis... that degrade carbofuran. Fourteen out of twenty-five microorganisms examined were found to degrade metalaxyl (5), and the involvement of pseudomonads has been implicated in degradation of atrazine (6). Further study of organisms capable of pesticide...

  6. Study of acaricide stability in honey. Characterization of amitraz degradation products in honey and beeswax.

    PubMed

    Korta, E; Bakkali, A; Berrueta, L A; Gallo, B; Vicente, F; Kilchenmann, V; Bogdanov, S

    2001-12-01

    A study on the possible degradation of amitraz, bromopropylate, coumaphos, chlordimeform, cymiazole, flumethrin, and tau-fluvalinate during the storage of honey was carried out by HPLC. Except amitraz, the other acaricides are stable in this medium for at least 9 months. Degradation studies of amitraz in honey and beeswax were carried out; the degradation products detected in both matrices were 2,4-dimethylphenylformamide (DMF) and N-(2,4-dimethylphenyl)-N'-methylformamidine (DPMF). The reaction rate constants and the half-lives of the amitraz degradation in honey and wax were calculated. Amitraz was nearly completely degraded within 1 day in beeswax and within 10 days in honey. When amitraz-spiked combs are recycled into new beeswax, DMF was found to be the principal degradation product left in pure wax. PMID:11743771

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

    PubMed

    de Solla, Shane Raymond; Martin, Pamela Anne; Mikoda, Paul

    2011-09-15

    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 mixtures within chemical classes, as well as complete mixtures. Eggs were incubated in the soil in a garden plot in which these mixtures were applied at a typical field application rate, and higher rates. Otherwise, the eggs were unmanipulated and were subject to ambient temperature and weather conditions. Eggs were also exposed at male producing temperatures in the laboratory in covered bins in the same soil, where there was less opportunity for loss through volatilization or leaching. Egg mortality was 100% at 10× the typical field application rate of the complete mixture, both with and without tefluthrin. At typical field application rates, hatching success ranged between 91.7 and 95.8%. Eggs exposed only to herbicides were not negatively affected at any application rates. Although fertilizer treatments at typical field application rates did not affect eggs, mortality was remarkably higher at three times this rate, and 100% at higher rates. The frequency of deformities of hatchlings was elevated at the highest application rate of the insecticide tefluthrin. The majority of the toxicity of the mixture was not due to the herbicides or insecticide, but was due to the ammonia fertilizer. At typical field application rates, the chemical regime associated with corn production does not appear to have any detrimental impacts upon turtle egg development; however toxicity dramatically increases if this threshold is passed. PMID:21831407

  8. Quantitative determination of catecholic degradation products from insect sclerotized cuticles.

    PubMed

    Andersen, Svend Olav

    2008-09-01

    Acid hydrolysates of cuticle from various insect species were quantitatively analyzed for five catecholic amino acid adducts. Four of the adducts are ketocatechols; in three of them the amino acid moiety, either lysine, glycine or beta-alanine, is connected via its amino group to the alpha-carbon atom of 3,4-dihydroxyacetophenone, in the fourth a tyrosine residue is connected to the same position via its phenolic group. The fifth adduct contains histidine linked via its imidazole-ring to the beta-position of the dopamine sidechain. The three ketocatecholic adducts containing alpha-amino acids were obtained in significant yields from adult cuticles of the locust Schistocerca gregaria, the cockroaches Blaberus craniifer and Periplaneta americana, and the beetles Pachynoda sinuata and Tenebrio molitor, but only in trace amounts from larval and pupal cuticles of T. molitor, pupal cuticles of the moths Manduca sexta and Hyalophora cecropia, and puparia of the blowfly Calliphora vicina. The beta-alanine-containing ketocatechol was not obtained from cuticle of locusts and T. molitor larvae and pupae, but it was present in the hydrolysates of the other cuticles. The beta-histidine-dopamine adduct was obtained from all the cuticles, the highest yield was obtained from adult P. sinuata and the lowest yield was from adult S. gregaria. The beta-histidine-dopamine adduct is derived from the product formed by reaction of p-quinone methides of N-acetyldopamine (NADA) or N-beta-alanyldopamine (NBAD) with histidine residues in the cuticular proteins. The ketocatecholic adducts are assumed to be degradation products of crosslinks formed when oxidized dehydro-NADA reacts with the cuticular proteins. The insect species investigated appear to use both pathways for sclerotization, but to widely differing extents; the dehydro-NADA pathway dominates in cuticles which are exposed to strong deforming forces, such as those of adult locusts and cockroaches, and the p-quinone methide pathway dominates in cuticle of lepidopteran pupae and blowfly puparia, which are not exposed to strong mechanical forces but have to be effectively protected against microbial and fungal attacks. PMID:18675913

  9. Paracoccus huijuniae sp. nov., an amide pesticide-degrading bacterium isolated from activated sludge of a wastewater biotreatment system.

    PubMed

    Sun, Li-Na; Zhang, Jun; Kwon, Soon-Wo; He, Jian; Zhou, Shun-Gui; Li, Shun-Peng

    2013-03-01

    A facultatively anaerobic, non-spore-forming, non-motile, catalase- and oxidase-positive, Gram-reaction-negative, coccoid to short rod-shaped strain, designated FLN-7(T), was isolated from activated sludge of a wastewater biotreatment facility. The strain was able to hydrolyse amide pesticides (e.g. diflubenzuron, propanil, chlorpropham and dimethoate) through amide bond cleavage. Strain FLN-7(T) grew at 4-42 °C (optimum 28 °C), at pH 5.0-8.0 (optimum pH 7.0) and with 0-5.0?% (w/v) NaCl (optimum 1.0?%). The major respiratory quinone was ubiquinone-10. The major cellular fatty acid was C18?:?1?7c. The genomic DNA G+C content of strain FLN-7(T) was 66.4±0.5 mol%. The major polar lipids were phosphatidylglycerol, phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylcholine and an unidentified glycolipid. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain FLN-7(T) was a member of the genus Paracoccus and showed highest 16S rRNA gene sequence similarities with Paracoccus aminovorans JCM 7685(T) (99.2?%), P. denitrificans DSM 413(T) (97.8?%), P. yeei CDC G1212(T) (97.3?%) and P. thiocyanatus THI 011(T) (97.1?%). Strain FLN-7(T) showed low DNA-DNA relatedness with P. aminovorans KACC 12261(T ()36.5±3.4?%), P. denitrificans KACC 12251(T) (30.5±2.6?%), P. yeei CCUG 46822(T) (26.2±2.4?%) and P. thiocyanatus KACC 13901(T) (15.5±0.9?%). Based on the phylogenetic analysis, DNA-DNA hybridization, whole-cell fatty acid composition and biochemical characteristics, strain FLN-7(T) was clearly distinguished from all recognized species of the genus Paracoccus and should be classified in a novel species, for which the name Paracoccus huijuniae sp. nov. is proposed. The type strain is FLN-7(T) (?=?KACC 16242(T) ?=?ACCC 05690(T)). PMID:22753523

  10. Degradation of triketone herbicides, mesotrione and sulcotrione, using advanced oxidation processes.

    PubMed

    Jovi?, Milica; Manojlovi?, Dragan; Stankovi?, Dalibor; Doj?inovi?, Biljana; Obradovi?, Bratislav; Gaši?, Uroš; Rogli?, Goran

    2013-09-15

    Degradation of two triketone herbicides, mesotrione and sulcotrione, was studied using four different advanced oxidation processes (AOPs): ozonization, dielectric barrier discharge (DBD reactor), photocatalysis and Fenton reagent, in order to find differences in mechanism of degradation. Degradation products were identified by high performance liquid chromatography (HPLC-DAD) and UHPLC-Orbitrap-MS analyses. A simple mechanism of degradation for different AOP was proposed. Thirteen products were identified during all degradations for both pesticides. It was assumed that the oxidation mechanisms in the all four technologies were not based only on the production and use of the hydroxyl radical, but they also included other kinds of oxidation mechanisms specific for each technology. Similarity was observed between degradation mechanism of ozonation and DBD. The greatest difference in the products was found in Fenton degradation which included the opening of benzene ring. When degraded with same AOP pesticides gave at the end of treatment the same products. Global toxicity and COD value of samples was determined after all degradations. Real water sample was used to study influence of organic matter on pesticide degradation. These results could lead to accurate estimates of the overall effects of triketone herbicides on environmental ecosystems and also contributed to the development of improved removal processes. PMID:23892174

  11. The role of fibrinogen, fibrin and fibrin(ogen) degradation products (FDPs) in tumor progression

    PubMed Central

    Ko?odziejczyk, Joanna

    2013-01-01

    Participation of fibrin, fibrinogen, and their degradation products in pathogenesis and progression of cancer may lead to complications of thromboembolic events. The tumor may be a source of fibrinogen. Fibrinogen inside the tumor is one of the factors of its growth and metastasis. Fibrinogen, fibrin and their degradation products possess proinflammatory activity. They indirectly stimulate endothelium to secrete von Willebrand factor, leading to activation of platelets accompanying neoplastic disorders. Fragments E and D are the end products of fibrin(ogen) degradation and E and DD are the end products of stabilized fibrin. E stimulates proliferation, migration and differentiation of endothelial cells, contributing to tumor vasculature. Increased levels of DD are observed in malignant neoplasms, such as breast, lung, colon and ovary cancers. In breast cancers DD correlates with progression of disease and metastasis. The role of fibrinogen and the products of its degradation in the progression of various tumors is not sufficiently understood. PMID:23788975

  12. Heterogeneous oxidation of pesticides on aerosol condensed phase

    NASA Astrophysics Data System (ADS)

    Socorro, Joanna; Durand, Amandine; Temime-Roussel, Brice; Ravier, Sylvain; Gligorovski, Sasho; Wortham, Henri; Quivet, Etienne

    2015-04-01

    Pesticides are widely used all over the world. It is known that they exhibit adverse health effects and environmental risks due to their physico-chemical properties and their extensive use which is growing every year. They are distributed in the atmosphere, an important vector of dissemination, over long distances away from the target area. The partitioning of pesticides between the gas and particulate phases influences their atmospheric fate. Most of the pesticides are semi-volatile compounds, emphasizing the importance of assessing their heterogeneous reactivity towards atmospheric oxidants. These reactions are important because they are involved in, among others, direct and indirect climate changes, adverse health effects from inhaled particles, effects on cloud chemistry and ozone production. In this work, the importance of atmospheric degradation of pesticides is evaluated on the surface of aerosol deliquescent particles. The photolysis processing and heterogeneous reactivity towards O3 and OH, was evaluated of eight commonly used pesticides (cyprodinil, deltamethrin, difenoconazole, fipronil, oxadiazon, pendimethalin, permethrin, tetraconazole) adsorbed on silica particles. Silicate particles are present in air-borne mineral dust in atmospheric aerosols, and heterogeneous reactions can be different in the presence of these mineral particles. Depending on their origin and conditioning, aerosol particles containing pesticides can have complex and highly porous microstructures, which are influenced by electric charge effects and interaction with water vapour. Therefore, the kinetic experiments and consecutive product studies were performed at atmospherically relevant relative humidity (RH) of 55 %. The identification of surface bound products was performed using GC-(QqQ)-MS/MS and LC-(Q-ToF)-MS/MS and the gas-phase products were on-line monitored by PTR-ToF-MS. Based on the detected and identified reaction products, it was observed that water plays a crucial role in the reaction mechanism of ozone and hydroxyl radical with the adsorbed pesticides on the silica particles. The obtained results will allow better understanding of the impact of pesticides and their degradation products on human health, and to make recommendations in order to reduce population exposure to the pesticide plume and the pollution by phyto-sanitary products on the regional scale, which constitutes a necessary step in the development of environmental strategies.

  13. Production scenarios and the effect of soil degradation on long-term food security in China

    Microsoft Academic Search

    Liming Ye; Eric Van Ranst

    2009-01-01

    Food security in China underlies the foundation of the livelihood and welfare for over one-fifth of the world's population. Soil degradation has an immense negative impact on the productive capacity of soils. We simulated the effect of soil degradation, which occurs in combination with increases in population size, urbanization rate, cropping intensity and decrease in cropland area, on long-term food

  14. Determination of degradation products from the calcium-channel blocker isradipine

    Microsoft Academic Search

    Michael G Bartlett; J Christopher Spell; Pheobe S Mathis; Maha F. A Elgany; Badr E El Zeany; Mohammed A Elkawy; James T Stewart

    1998-01-01

    Mass Spectrometry has been used to determine the identity of a number of degradation products from the bulk drug form of Isradipine (DynaCirc). Liquid chromatography coupled with mass spectrometry (LC\\/MS) was used to analyze the degraded samples and tentative identifications were made based upon the known reactivity of the molecule, molecular weight measurements and mass spectral fragmentation patterns. Isradipine was

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

    PubMed Central

    2014-01-01

    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. PMID:24919821

  16. Evaluation of vegetable production management practices to reduce the ecological risk of pesticides.

    PubMed

    Rice, Pamela J; Hapeman, Cathleen J; McConnell, Laura L; Sadeghi, Ali M; Teasdale, John R; Coffman, C Benjamin; McCarty, Gregory W; Abdul-Baki, Aref A; Starr, James L

    2007-11-01

    The ability of agricultural management practices to reduce the ecological risks of pesticides was evaluated. Risk quotients, a mathematical description of the relationship between exposure and toxicity, and hazard ratings, a rank of the potential risk of pesticides to aquatic environments, were calculated for conventional and alternative cultivation practices for tomatoes: Poly-Bare, raised beds covered with polyethylene mulch with bare-soil furrows; Poly-Rye, raised beds covered with polyethylene mulch with cereal rye (Secale cereale) grown in the furrows; and Vetch, raised beds and furrows planted with hairy vetch seed (Vicia villosa). Evaluations were conducted using measured pesticide concentrations in runoff at the edge-of-field and estimated environmental concentrations in an adjacent creek and a theoretical pond receiving the runoff. Runoff from Poly-Bare presented the greatest risk to ecosystem health and to sensitive organisms, whereas the use of Vetch minimized these risks. Previous studies have shown that harvest yields were maintained and that runoff volume, soil loss, and off-site transport of pesticides measured in runoff were reduced using the alternative management practices (Poly-Rye and Vetch). Together, these results indicate that the alternative management practices (Poly-Rye and Vetch) have a less adverse impact on the environment than the conventional management practice (Poly-Bare) while providing growers with an acceptable economic return. In addition, the present study demonstrates the need to consider the management practice when assessing the potential risks and hazards for certain pesticides. PMID:17941735

  17. Pesticides: Protecting Workers

    MedlinePLUS

    ... and load pesticides, or requiring specific personal protective equipment, such as gloves, to protect users against risks associated with the product contacting their skin. EPA’s risk management process produces labeling containing directions for use, storage, ...

  18. Occurrence and distribution of organochlorine pesticides (OCPs) in tomato (Lycopersicon esculentum) crops from organic production.

    PubMed

    Gonzalez, Mariana; Miglioranza, Karina S B; Aizpún de Moreno, Julia E; Moreno, Víctor J

    2003-02-26

    Organochlorine pesticides (OCPs) were quantified by GC-ECD in tomato (Lycopersicon esculentum) during a vegetation period. Plants were harvested at 15, 60, and 151 days after seed germination. Leaves, stem, roots, and fruit (peel and flesh) were analyzed separately. The results showed that tomato plants were able to accumulate OCPs from soils, and a trend to reach the equilibrium among tissues at mature stages was also observed. Endosulfans comprised the main OCP group, probably due to its spray during summer months in the surrounding areas. Banned pesticides such as DDTs, heptachlor, and dieldrin were found. OCPs levels in the fruit were below the maximum residues limits (MRL) considered by the Codex Alimentarius. DDE/DDT and alpha-/gamma-HCH ratios of <1 would indicate recent inputs of DDT and lindane in the environment. The occurrence of OCPs in the study farm, where agrochemicals have never been used, is a result of atmospheric deposition of those pesticides. PMID:12590481

  19. ANALYSIS OF GLUCOSINOLATES AND GLUCOSINOLATE DEGRADATION PRODUCTS IN SPROUTING BROCCOLI SEEDS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Total glucosinolate content and glucosinolate degradation products were examined in unsprouted `Marathon' broccoli (Brassica oleracea L., Italica group) seeds and in 1-, 2-, 3-, 5-, 7-, and 10-day-old sprouts. Glucosinolates identified were glucoiberin, glucoraphanin, gluconapin, glucoiberverin, 4-...

  20. 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...

  1. Comparative Aquatic Toxicity Evaluation of 2-(Thiocyanomethylthio)benzothiazole and Selected Degradation Products Using Ceriodaphnia dubia

    Microsoft Academic Search

    S. T. Nawrocki; K. D. Drake; C. F. Watson; G. D. Foster; K. J. Maier

    2005-01-01

    2-(Thiocyanomethylthio)benzothiazole (TCMTB) is a biocide used in the leather, pulp and paper, and water-treatment industries. TCMTB may enter aquatic ecosystems during its manufacture and use. TCMTB is environmentally unstable; therefore, it is important to evaluate the toxicity of the more persistent degradation products. This study compared the toxicity of TCMTB with its degradation products 2-mercaptobenzothiazole (2-MBT), 2-(methylthio)benzothiazole (MTBT), benzothiazole (BT),

  2. Formation of fluorescent substances from degradation products of methyl linoleate hydroperoxides with amino compound

    Microsoft Academic Search

    Toshihiro Iio; Kazuaki Yoden

    1988-01-01

    The degradation products formed from methyl linoleate hydroperoxides by reaction with heme were fractionated by Sephadex LH-20\\u000a column chromatography and by reverse-phase high performance liquid chromatography, and the ability of each compound to form\\u000a fluorescent substances through reaction with amino compound was compared. Maximum formation of fluorescent substances was\\u000a obtained from monomeric degradation products with amino compound, but low molecular

  3. USE OF LINED PITS FOR DISPOSAL OF DILUTE PESTICIDE WASTE

    EPA Science Inventory

    Modern agricultural practices rely heavily on the use of pesticides to sustain high productivity. When pesticide containers and application equipment are rinsed after use, the contaminated water requires proper disposal. At Iowa State University in Ames, Iowa, dilute pesticide ri...

  4. Assessment of dental material degradation product toxicity using a bioluminescent bacterial assay

    Microsoft Academic Search

    Melissa G Shettlemore; Kirk J Bundy

    2002-01-01

    Objectives: This study examined dental material degradation product toxicity using the Microtox bacterial bioluminescence assay as well as the effects on toxicity of selective leaching, chelation with protein, the physical form of the products, and synergistic\\/antagonistic interactions among released ions.Methods: Polarization was used to produce ionically dissolved (ID) and precipitated corrosion products from Litecast B alloy specimens, which were then

  5. Soil column leaching of pesticides.

    PubMed

    Katagi, Toshiyuki

    2013-01-01

    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

  6. Pesticide Q&A

    MedlinePLUS

    ... Contaminants Pesticides Glossary of Pesticide Chemicals Pesticide Program Residue Monitoring Pesticide Q&A Pesticide Q&A Who ... the United Sates? The responsibility for ensuring that residues of pesticides in foods are not present at ...

  7. Pesticide residue assessment in three selected agricultural production systems in the Choluteca River Basin of Honduras

    Microsoft Academic Search

    J Kammerbauer; J Moncada

    1998-01-01

    There is a basic lack of information about the presence of pesticide residues in the environment in Central America. Over the period of February 1995 to June 1997, river, well, lagoon and spring water samples, as well as soil, fish tissue, lagoon bed sediments and some foodstuffs were taken from the greater Cholutecan River Basin of Honduras and analyzed for

  8. 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...

  9. [Activity of PZ-peptidase in blood serum of workers from a pesticide dust production factory].

    PubMed

    Kossmann, S; Grabowska-Bochenek, R; Konieczny, B; Kocha?ski, L

    1990-01-01

    In 31 subjects with an occupational exposure to dust pesticides the levels of PZ-peptidase, alpha-1-antitrypsin, alpha-2-macroglobulin were determined. A decrease of PZ-peptidase and an increase of alpha-1-antitrypsin, alpha-2-macroglobulin were found in comparison with a control group of 30 healthy volunteers. PMID:8614674

  10. Production of Trichoderma strains with pesticide-polyresistance by mutagenesis and protoplast fusion.

    PubMed

    Hatvani, Lóránt; Manczinger, László; Kredics, László; Szekeres, András; Antal, Zsuzsanna; Vágvölgyi, Csaba

    2006-01-01

    The sensitivity of two cold-tolerant Trichoderma strains belonging to the species T. harzianum and T. atroviride was determined to a series of pesticides widely used in agriculture. From the 16 pesticides tested, seven fungicides: copper sulfate, carbendazim, mancozeb, tebuconazole, imazalil, captan and thiram inhibited colony growth of the test strains significantly with minimal inhibitory concentrations of 300, 0.4, 50, 100, 100, 100 and 50 microg/ml, respectively. Mutants resistant to carbendazim and tebuconazole were produced from both wild type strains by means of UV-mutagenesis. The cross-resistance capabilities and in vitro antagonistic properties of the mutants were determined. Carbendazim-resistant mutants showed total cross-resistance to benomyl and thiabendazole at a concentration of 20 microg/ml. Intraspecific protoplast fusion was carried out between carbendazim- and tebuconazole-resistant mutants of both parental strains, and putative haploid recombinants with stable resistance to both pesticides were produced in the case of T. atroviride. These pesticide-polyresistant progenies are potential candidates for application in an integrated pest management system. PMID:16779635

  11. 76 FR 35383 - Pesticides; Policies Concerning Products Containing Nanoscale Materials; Opportunity for Public...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-17

    ...certain information on the detection of pesticide residues in water, food, and feed (40 CFR 159.178); and new studies of...or optical properties--or features, such as improved hardness or strength, that are highly desirable for applications...

  12. Fungal degradation of coal as a pretreatment for methane production

    USGS Publications Warehouse

    Haider, Rizwan; Ghauri, Muhammad A.; SanFilipo, John R.; Jones, Elizabeth J.; Orem, William H.; Tatu, Calin A.; Akhtar, Kalsoom; Akhtar, Nasrin

    2013-01-01

    Coal conversion technologies can help in taking advantage of huge low rank coal reserves by converting those into alternative fuels like methane. In this regard, fungal degradation of coal can serve as a pretreatment step in order to make coal a suitable substrate for biological beneficiation. A fungal isolate MW1, identified as Penicillium chrysogenum on the basis of fungal ITS sequences, was isolated from a core sample of coal, taken from a well drilled by the US. Geological Survey in Montana, USA. The low rank coal samples, from major coal fields of Pakistan, were treated with MW1 for 7 days in the presence of 0.1% ammonium sulfate as nitrogen source and 0.1% glucose as a supplemental carbon source. Liquid extracts were analyzed through Excitation–Emission Matrix Spectroscopy (EEMS) to obtain qualitative estimates of solubilized coal; these analyses indicated the release of complex organic functionalities. In addition, GC–MS analysis of these extracts confirmed the presence of single ring aromatics, polyaromatic hydrocarbons (PAHs), aromatic nitrogen compounds and aliphatics. Subsequently, the released organics were subjected to a bioassay for the generation of methane which conferred the potential application of fungal degradation as pretreatment. Additionally, fungal-mediated degradation was also prospected for extracting some other chemical entities like humic acids from brown coals with high huminite content especially from Thar, the largest lignite reserve of Pakistan.

  13. Pesticides: Glossary

    MedlinePLUS

    ... are thus important to Integrated Pest Management programs. biological pesticide - A chemical which is derived from plants, ... and which can be used for pest control. biological pesticide - Certain microorganisms , including bacteria, fungi, viruses, and ...

  14. [Surface-enhanced Raman spectra analysis of trace degradation products from goat horn].

    PubMed

    Pan, Yan-Ting; Ao, Ning-Jian; Shan, Guang-Hua; Zhang, Gang-Ping; Zhang, Quan-Bin; Yang, Ji-Wang; He, Chun-Lan; Huang, Yao-Xiong

    2014-04-01

    Nano-silver colloid was synthesized by using microwave method on the mixtures of sodium citrate solution and silver nitrate solution. The method has advantages of fast heating speed, uniform temperature distribution and easily controlled reaction conditions. The sizes and size distributions of the silver particles were characterized by means of quasi-elastic laser scattering (QLS). The average particles size was (53.27 +/- 2.65) nm and the size of the particles was mainly distributed around 56 nm. Surface-enhanced Raman spectra of the degradation products from goat horn were obtained with silver colloid as active substrate. It was observed that the Raman signal of SERS was enhanced significantly compared with that of regular Raman spectrum, especially at the Raman bands of 659, 830, 850, 929, 999, 1 028, 1 280, 1 439 and 1 599 cm(-1) which reflect the biochemical components in degradation products. The characteristic Raman bands of degradation products from goat horn were preliminary assigned. The assignments showed that the main constituents of the degradation products from goat horn were amino acids and polypeptides. It was for the first time that Surface-enhanced Raman spectroscopy was used to detect trace degradation products from the horns. Raman signal enhancement can be obtained with high sensitivity for the trace concentrations as low as ppm level. It is concluded that surface-enhanced Raman spectroscopy can provide a fast, direct and precise detecting method for the detection of trace degradation solution from horns. PMID:25007614

  15. Comparative aquatic toxicity evaluation of 2-(thiocyanomethylthio)benzothiazole and selected degradation products using Ceriodaphnia dubia.

    PubMed

    Nawrocki, S T; Drake, K D; Watson, C F; Foster, G D; Maier, K J

    2005-04-01

    2-(Thiocyanomethylthio)benzothiazole (TCMTB) is a biocide used in the leather, pulp and paper, and water-treatment industries. TCMTB may enter aquatic ecosystems during its manufacture and use. TCMTB is environmentally unstable; therefore, it is important to evaluate the toxicity of the more persistent degradation products. This study compared the toxicity of TCMTB with its degradation products 2-mercaptobenzothiazole (2-MBT), 2-(methylthio)benzothiazole (MTBT), benzothiazole (BT), and 2-hydroxybenzothiazole (HOBT). Toxicity was determined using Ceriodaphnia dubia 48-hour acute and 7-day chronic test protocols. TCMTB was the most toxic compound evaluated in both the acute and chronic tests with EC50s of 15.3 and 9.64 microg/L, respectively. 2-MBT, the first degradation product, was the second most toxic compound with acute and chronic EC50s of 4.19 and 1.25 mg/L, respectively. The toxicity of MTBT and HOBT were similar with acute EC50s of 12.7 and 15.1 mg/L and chronic EC50s of 6.36 and 8.31 mg/L, respectively. The least toxic compound was BT with acute and chronic EC50s of 24.6 and 54.9 mg/L, respectively. TCMTB was orders of magnitude more toxic than its degradation products. Toxicity data on these benzothiazole degradation products is important because of concerns regarding their release, degradation, persistence, and non-target organism effects in aquatic ecosystems. PMID:15750776

  16. Activity of Meadowfoam (Limnanthes alba) Seed Meal Glucolimnanthin Degradation Products against Soil-Borne Pathogens

    PubMed Central

    ZASADA, INGA A; WEILAND, JERRY E; REED, RALPH L; STEVENS, JAN F

    2014-01-01

    Meadowfoam (Limnanthes alba L.) is a herbaceous winter-spring annual grown as a commercial oil seed 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 soil-borne 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 soil-borne 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 soil-borne 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 soil-borne pathogens with M. hapla being the most sensitive with EC50 values (0.0025 ± 0.0001 to 0.0027 ± 0.0001 mg/mL) 20 to 40 times lower than estimated EC50 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

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

    PubMed

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

    2011-05-01

    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

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

    NASA Astrophysics Data System (ADS)

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

    2006-01-01

    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.

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

    PubMed

    El-Gindy, Alaa

    2005-08-01

    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

  20. Identification of Forced Degradation Products of Itopride by LC-PDA and LC-MS

    PubMed Central

    Joshi, Payal; Bhoir, Suvarna; Bhagwat, A. M.; Vishwanath, K.; Jadhav, R. K.

    2011-01-01

    Degradation products of itopride formed under different forced conditions have been identified using LC-PDA and LC-MS techniques. Itopride was subjected to forced degradation under the conditions of hydrolysis, photolysis, oxidation, dry and wet heat, in accordance with the International Conference on Harmonization. The stress solutions were chromatographed on reversed phase C18 (250×4.6 mm, 5 ?m) column with a mobile phase methanol:water (55:45, v/v) at a detection wavelength of 215 nm. Itopride degraded in acid, alkali and oxidative stress conditions. The stability indicating method was developed and validated. The degradation pathway of the drug to products II-VIII is proposed. PMID:22457552

  1. Identification of Forced Degradation Products of Itopride by LC-PDA and LC-MS.

    PubMed

    Joshi, Payal; Bhoir, Suvarna; Bhagwat, A M; Vishwanath, K; Jadhav, R K

    2011-05-01

    Degradation products of itopride formed under different forced conditions have been identified using LC-PDA and LC-MS techniques. Itopride was subjected to forced degradation under the conditions of hydrolysis, photolysis, oxidation, dry and wet heat, in accordance with the International Conference on Harmonization. The stress solutions were chromatographed on reversed phase C18 (250×4.6 mm, 5 ?m) column with a mobile phase methanol:water (55:45, v/v) at a detection wavelength of 215 nm. Itopride degraded in acid, alkali and oxidative stress conditions. The stability indicating method was developed and validated. The degradation pathway of the drug to products II-VIII is proposed. PMID:22457552

  2. Degradation of biotansformation products of nonylphenol ethoxylates by ozonation and UV/TiO2 treatment.

    PubMed

    Ike, M; Asano, M; Belkada, F D; Tsunoi, S; Tanaka, M; Fujita, M

    2002-01-01

    The degradation kinetics of biotransformation products of nonylphenol polyethoxylates (NPEOs), nonylphenol (NP), nonylphenol monoethoxylate (NP1EO) and nonylphenoxy carboxylic acid (NP1EC), by ozonation and UV/TiO2 (ultraviolet photocatalytic degradation in the presence of titanium dioxide suspension as a catalyst) were investigated using lab-scale reactors. The degradation rate of NP by UV/TiO2 was the highest among the tested NPEOs metabolites, while NP1EC showed the lowest degradation rate. In contrast, ozonation was especially effective for the breakdown of NP1EC. NP could be also degrade efficiently by ozonation, however, it was much less effective for NP1EO decomposition. Degradation of NP by both chemical oxidation processes followed first-order kinetics. The degradation curves of NP1EO and NP1EC could be approximately described by first-order kinetics also, although the degradation of NP1EC by ozonation seemed to follow a second-order kinetic. PMID:12523743

  3. Farmers and Pesticides

    NSDL National Science Digital Library

    American Association for the Advancement of Science (; )

    2006-05-23

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

  4. 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...

  5. Photocatalytic degradation of molinate in aqueous solutions.

    PubMed

    Bizani, E; Lambropoulou, D; Fytianos, K; Poulios, I

    2014-11-01

    In this study, the degradation of molinate through heterogeneous photocatalysis, using two different types of the semiconductor TiO2 as photocatalyst, as well as through homogeneous treatment, applying the photo-Fenton reaction, has been investigated. As far as heterogeneous photocatalysis is concerned, the degradation of the pesticide follows apparent first-order kinetics, while the type of the catalyst and the pH value of the solution affect the degradation rate. The effect of the addition of electron scavengers (H2O2 and K2S2O8) was also studied. In the case of photo-Fenton-assisted system, the degradation also follows pseudo-first-order kinetics. Parameters such as iron's and electron scavenger's concentration and inorganic ions strongly affect the degradation rate. The extent of pesticide mineralization was investigated using dissolved organic carbon (DOC) measurements. The toxicity of the treated solution was evaluated using the Microtox test based on the luminescent bacteria Vibrio fischeri. The detoxification and mineralization efficiency was found to be dependent on the system studied, and although it did not follow the rate of pesticide disappearance, it took place in considerable extent. The study of the photodegradation treatment was completed by the determination of the intermediate by-products formed during the process, which was carried out using LC-MS/MS technique and led to similar compounds with both processes. PMID:24928378

  6. Organophosphorous pesticide breakdown products in house dust and children’s urine

    PubMed Central

    Quirós-Alcalá, Lesliam; Bradman, Asa; Smith, Kimberly; Weerasekera, Gayanga; Odetokun, Martins; Barr, Dana Boyd; Nishioka, Marcia; Castorina, Rosemary; Hubbard, Alan E.; Nicas, Mark; Hammond, S. Katharine; McKone, Thomas E.; Eskenazi, Brenda

    2014-01-01

    Human exposure to preformed dialkylphosphates (DAPs) in food or the environment may affect the reliability of DAP urinary metabolites as biomarkers of organophosphate (OP) pesticide exposure. We conducted a study to investigate the presence of DAPs in indoor residential environments and their association with children’s urinary DAP levels. We collected dust samples from homes in farmworker and urban communities (40 homes total, n = 79 samples) and up to two urine samples from resident children ages 3–6 years. We measured six DAPs in all samples and eight DAP-devolving OP pesticides in a subset of dust samples (n = 54). DAPs were detected in dust with diethylphosphate (DEP) being the most frequently detected (?60%); detection frequencies for other DAPs were ?50%. DEP dust concentrations did not significantly differ between communities, nor were concentrations significantly correlated with concentrations of chlorpyrifos and diazinon, the most frequently detected diethyl-OP pesticides (Spearman ? = ?0.41 to 0.38, P>0.05). Detection of DEP, chlorpyrifos, or diazinon, was not associated with DEP and/or DEP + diethylthiophosphate detection in urine (Kappa coefficients = ?0.33 to 0.16). Finally, estimated non-dietary ingestion intake from DEP in dust was found to be ?5% of the dose calculated from DEP levels in urine, suggesting that ingestion of dust is not a significant source of DAPs in urine if they are excreted unchanged. PMID:22781438

  7. Emulsifying Agent Production During PAHs Degradation by the White Rot Fungus Pleurotus Ostreatus D1

    Microsoft Academic Search

    Svetlana V. Nikiforova; Natalia N. Pozdnyakova; Olga V. Turkovskaya

    2009-01-01

    For the first time the production of an emulsifying agent during phthalic, 2,2?-diphenic and ?-hydroxy-?-naphthoic acids,\\u000a phenanthrene, anthracene, fluorene, pyrene, fluoranthene, and chrysene degradation by white rot fungus Pleurotus ostreatus was found. The emulsifying activity of the cultivation medium after degradation of these compounds was assessed. Maximal\\u000a activities were found in the presence of chrysene (48.4%) and ?-hydroxy-?-naphthoic acid (52.2%).

  8. Stability studies on trans-rosmarinic acid and GC–MS analysis of its degradation product

    Microsoft Academic Search

    Maša Islam?evi? Razboršek

    2011-01-01

    The stability of trans-rosmarinic acid (trans-RA, an important phenolic compound with anti-oxidant, anti-inflammatory, anti-bacterial, and anti-viral properties) exposed to different stress conditions (daylight, higher temperatures, different solvents, and humidity) was investigated. Gas chromatography–mass spectrometry (GC–MS) was used to analyse the degraded samples, and structural identification of degradation products was assigned based upon MS fragmentation pattern. The GC–MS method was validated

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

    Microsoft Academic Search

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

    2003-01-01

    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

  10. Degradation of selected pharmaceutical and personal care products (PPCPs) by white-rot fungi

    Microsoft Academic Search

    A. I. Rodarte-Morales; G. Feijoo; M. T. Moreira; J. M. Lema

    Today, more than 3,000 pharmaceutical and personal care products (PPCPs) are used and released into the environment at low\\u000a doses but they are barely degraded in wastewater treatment plants. One of the potential alternatives to effectively degrade\\u000a PPCPs is based on the use of white-rot fungi (WRF) and involves the oxidative action of extracellular fungal enzymes. The\\u000a aim of this

  11. PRODUCTION OF HIGHLY ACTIVE LIGNOCELLULOSE-DEGRADING ENZYMES OF ANAEROBIC FUNGI BY INDUSTRIALLY RELEVANT FUNGI

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Most anaerobic fungi isolated from the digestive tracts of herbivorous animals secrete highly active lignocellulose-degrading enzymes, but the levels of production are usually low (e.g., <50 mg per liter). Fungi such as Trichoderma and Aspergillus, that are commonly used for commercial production o...

  12. Bivariate degradation analysis of products based on Wiener processes and copulas

    Microsoft Academic Search

    Zhengqiang Pan; Narayanaswamy Balakrishnan; Quan Sun; Jinglun Zhou

    2012-01-01

    Modern highly reliable products usually have complex structure and many functions. This means that they may have two or more performance characteristics. All the performance characteristics can reflect the product's performance degradation over time, and they may be independent or dependent. If the performance characteristics are independent, they can be modelled separately. But if they are not independent, it is

  13. The ARS Pesticide Properties Database

    NSDL National Science Digital Library

    2005-01-01

    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.

  14. 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.

  15. Weed Control Methods This information is not a substitute for pesticide labeling. Always read the product label before applying any pesticide. Always check NYS registration

    E-print Network

    Keinan, Alon

    Weed Control Methods This information is not a substitute for pesticide labeling. Always read. It is a resource to compare weed control methods and herbicide label information. Thermal Mechanical Barrier effective on newly emerged annuals Small weeds Few, large weeds Long- term control Best on young annuals Air

  16. Microbial petroleum degradation enhancement by oil spill bioremediation products

    E-print Network

    Lee, Salvador Aldrett

    1996-01-01

    Biodegradation of an artificially weathered crude oil (Alaska North Slope) was compared using 13 different oil spill bioremediation agents. All products were evaluated under identical conditions emulating a marine environment. The research...

  17. Correction for irrelevant absorption in multicomponent spectrophotometric assay of riboflavin, formylmethylflavin, and degradation products: kinetic applications.

    PubMed

    Ahmad, Iqbal; Qadeer, Kiran; Iqbal, Kefi; Ahmed, Sofia; Sheraz, Muhammad Ali; Ali, Syed Abid; Mirza, Tania; Hafeez, Ambreen

    2013-09-01

    In the spectrophotometric assay of multicomponent systems involved in drug degradation studies, some minor or unknown degradation products may be present. These products may interfere in the assay and thus invalidate the results due to their absorption in the range of analytical wavelengths. This interference may be eliminated by the application of an appropriate correction procedure to obtain reliable data for kinetic treatment. The present study is based on the application of linear and non-linear irrelevant absorption corrections in the multicomponent spectrophotometric assay of riboflavin and formylmethylflavin during the photolysis and hydrolysis studies. The correction procedures take into account the interference caused by minor or unknown products and have shown considerable improvement in the assay data in terms of the molar balance. The treatment of the corrected data has led to more accurate kinetic results in degradation studies. PMID:23821430

  18. Systematic identification of thermal degradation products of HPMCP during hot melt extrusion process.

    PubMed

    Karandikar, Hrushikesh; Ambardekar, Rohan; Kelly, Adrian; Gough, Tim; Paradkar, Anant

    2015-05-30

    A systematic identification of the degradation products of hydroxypropyl methylcellulose phthalate (HPMCP) during hot melt extrusion (HME) has been performed. A reverse phase HPLC method was developed for the extrudates of both hydroxypropyl methylcellulose acetate succinate (HPMCAS) and HPMCP polymers to quantify their thermal hydrolytic products: acetic acid (AA), succinic acid (SA) for HPMCAS and phthalic acid (PA) for HPMCP, without hydrolysing the polymers in strong alkaline solutions. The polymers were extruded in the temperature range of 160-190°C at different screw rotation speeds and hydrolytic impurities were analysed. Investigation of extruded HPMCP showed an additional thermal degradation product, who is structural elucidation revealed to be phthalic anhydride (PAH). Moreover, two environmental analytical impurities, dimethyl phthalate and methyl benzoate formed in situ were recorded on GC-MS and their origin was found to be associated with PAH derivatization. Using the experimental data gathered during this study, a degradation mechanism for HPMCP is proposed. PMID:25845717

  19. Biodegradation of organophosphorus pesticides by soil bacteria

    NASA Astrophysics Data System (ADS)

    de Pasquale, C.; Fodale, R.; Lo Piccolo, L.; Palazzolo, E.; Alonzo, G.; Quatrini, P.

    2009-04-01

    A number of studies in the 1980s and 1990s showed that crop-protection products, applied to drained fields, could move downwards through the soil profile and to the groundwater. Organophosphorus insecticides (OPs) are used all over the world for crop protection, for other agricultural practices such as sheep dipping and, in aquaculture, for the control of sea lice. Ops besides showing a specific neurotoxicity and have also been related to various modern diseases, including Creutzfeldt-Jakob (CJD) and the Gulf War syndrome. Although OPs are less persistent than Organoclorine pesticides (OCs), they still constitute an environmental risks thus increasing the social concern about their levels in soils, surface waters, and ground waters. Degradation of OPs by microorganisms has been assessed for a few bacterial strains. In the present study the OPs degrading potential of indigenous soil microorganisms was investigated. Using enrichment cultures in which parathion was the only C and energy sources many bacterial strains were isolated from OPs contaminated and pristine agricultural soils characterized by different physico-chemical properties. More than 40 potential OPs degraders were isolated and grouped in operational taxonomic units (OTU) using analysis of polymorphism showed by the ribosomal internal transcribed spacer (ITS). Partial sequencing of 16S rRNA gene of representative isolates of each OTU revealed that most of them belong to Proteobacteria and Actinobacteria. All the analyzed soils showed the presence of putative OPs degraders: the highest diversity was found in organic cultivated soils, the lowest in chemically cultivated soils. Degradation of different OPs, characterized by different physical and chemical properties, was obtained by different selected representative strains using SPME GC-MS analysis on water and soil microcosms. The results showed that, after the incubation period, the amount of pesticide residues were in the range 20-80%. Some of the isolates bacterial species are currently unknown as OPs degraders.

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

    PubMed

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

    1999-12-01

    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. PMID:10585900

  1. A procedure for production of adapted bacteria to degrade chlorinated aromatics

    Microsoft Academic Search

    C. Seignez; A. Vuillemin; N. Adler; P. Peringer

    2001-01-01

    Production of biomass adapted to the degradation of a mixture of chlorobenzene (CB) and 1,2-dichlorobenzene (DCB) was investigated in a batch culture with substrates supplied by pulses. CB and o-DCB concentrations which gave the best adapted biomass productivity were determined and found to be 150 and 30?ll?1, respectively. The biomass productivity was 51mgl?1h?1. The biomass yield was 0.38g of biomass

  2. Soil analyses for 1,3-dichloropropene (1,3-DCP), sodium n-methyldithiocarbamate (metam-sodium), and their degradation products near Fort Hall Idaho, September 1999 through March 2000

    USGS Publications Warehouse

    Parliman, D.J.

    2001-01-01

    Between September 1999 and March 2000, soil samples from the Fort Hall, Idaho, area were analyzed for two soil fumigants, 1,3-dichloropropene (1,3-DCP) and sodium n-methyldithiocarbamate (metam-sodium), and their degradation products. Ground water is the only source of drinking water at Fort Hall, and the purpose of the investigation was to determine potential risk of ground-water contamination from persistence and movement of these pesticides in cropland soils. 1,3-DCP, metam-sodium, or their degradation products were detected in 42 of 104 soil samples. The samples were collected from 1-, 2-, and 3-foot depths in multiple backhoe trenches during four sampling events—before pesticide application in September; after application in October; before soil freeze in December; and after soil thaw in March. In most cases, concentrations of the pesticide compounds were at or near their laboratory minimum reporting limits. U.S. Environmental Protection Agency Method 5035 was used as the guideline for soil sample preparation and analyses, and either sodium bisulfate (NaHSO4), an acidic preservative, or pesticide-free water was added to samples prior to analyses. Addition of NaHSO4 to the samples resulted in a greater number of compound detections, but pesticide-free water was added to most samples to avoid the strong reactions of soil carbonate minerals with the NaHSO4. As a result, nondetection of compounds in samples containing pesticide-free water did not necessarily indicate that the compounds were absent. Detections of these compounds were inconsistent among trenches with similar soil characteristics and histories of soil fumigant use. Compounds were detected at different depths and different trench locations during each sampling event. Overall results of this study showed that the original compounds or their degradation products can persist in soil 6 months or more after their application and are present to at least 3 feet below land surface in some areas. A few of the soil analyses results were unexpected. Degradation products of metam-sodium were detected in samples from croplands with a history of 1,3-DCP applications only, and were not detected in samples from croplands with a history of metam-sodium applications. Although 1,2-dibromoethane (EDB) has not been used in the area for many years, EDB was detected in a few soil samples. The presence of EDB in soil could be caused by irrigation of croplands with EDBcontaminated ground water. Analyses of these soil samples resulted in many unanswered questions, and further studies are needed. One potential study to determine vertical extent of pesticide compound migration in sediments, for example, would include analysis of one or more columns of soil and sediments (land surface to ground water, about 35 to 50 feet below land surface) in areas with known soil contamination. Another study would expand the scope of soil contamination to include broader types of cropland conditions and compound analyses.

  3. Hydrothermal degradation of lignin: products analysis for phenol formaldehyde adhesive synthesis.

    PubMed

    Yang, Sheng; Yuan, Tong-Qi; Li, Ming-Fei; Sun, Run-Cang

    2015-01-01

    Corncob lignin was treated with pressurized hot water in a cylindrical autoclave in current investigation. With the aim of investigating the effect of reaction temperature and retention time on the distribution of degradation products, the products were divided into five fractions including gas, volatile organic compounds, water-soluble oil, heavy oil, and solid residue. It was found that hydrothermal degradation of corncob lignin in pressurized hot water produced a large amount of phenolic compounds with lower molecular weight than the raw lignin. Some phenolic and benzene derivatives monomers such as vanillin, 2-methoxy-phenol, 2-ethyl-phenol, p-xylene, and 1, 3-dimethyl-benzene were also identified in the degradation products. The products were further analyzed by GC-MS, GPC, 2D-HSQC, and (31)P-NMR to investigate their suitability for partial incorporation into phenol formaldehyde adhesive as a substitution of phenol. The results indicated that the reaction temperature had more effect on the products distribution than the retention time. The optimal condition for heavy oil production appeared at 290 °C with retention time 0 min. The compounds of heavy oil had more active sites than the raw lignin, suggesting that the heavy oil obtained from hydrothermal degradation of lignin is a promising material for phenol formaldehyde adhesive synthesis. PMID:25109457

  4. Degradation and Sorption of Imidacloprid in Dissimilar Surface and Subsurface Soils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Degradation and sorption/desorption are important processes affecting the leaching of pesticides through soil. Once pesticides move past the surface soil layers, subsurface soil physical, chemical, and biological properties significantly affect pesticide fate and the potential for groundwater contam...

  5. Retrospective analysis for the identification of 4-aminocarminic acid photo-degradation products in beverages.

    PubMed

    Gosetti, Fabio; Chiuminatto, Ugo; Mastroianni, Rita; Mazzucco, Eleonora; Manfredi, Marcello; Marengo, Emilio

    2015-03-01

    This article deals with the identification of the photo-degradation products of 4-aminocarminic acid potentially present in commercial beverages. Sixteen beverages of different composition but all containing the E120 dye were previously analysed by ultra-high-performance liquid chromatography (UHPLC) coupled with quadrupole-time of flight mass spectrometry to identify the common degradation products of the E120 dye. Since it is plausible to find unauthorised 4-aminocarminic acid in beverages which report generic E120 dye on the label, retrospective analysis was employed here not only to search for the possible presence of 4-aminocarminic acid but also to investigate the potential formation of photo-degradation products derived from this compound. For this purpose, a statistical approach based on Student's t-test was used to compare the degraded beverages containing 4-aminocarminic acid with all the others. Five degradation products were identified and their structures were elucidated on the basis of the high-accuracy and high-resolution of mass and mass/mass spectra. The toxicity of the degradation products was evaluated through the Ames Salmonella/microsome mutagenicity assay. No evidence of mutagenicity was obtained for the beverages subjected or not to irradiation, whereas a toxic effect of the 4-aminocarminic acid standard solution already at 100.0 µg l(-1) was found. This leads, once again, to the conclusion that the toxicity study must be carried out on the beverages in order to take into account of all the possible masking/protection interactions among the ingredients. PMID:25562586

  6. Stability-indicating spectrofluorometric method for the determination of some cephalosporin drugs via their degradation products.

    PubMed

    Mostafa, Nadia M; Abdel-Fattah, Laila; Weshahy, Soheir A; Hassan, Nagiba Y; Boltia, Shereen A

    2015-01-01

    A stability-indicating spectrofluorometric method was investigated for the determination of three cephalosporin drugs, namely, cefpodoxime proxetil (CPD), cefixime trihydrate (CFX), and cefepime hydrochloride (CPM), via their acid and alkali degradation products. The three drugs were determined via their acid degradation at 432, 422, and 435 nm using an excitation wavelength of 310, 330, and 307 nm for CPD, CFX, and CPM determination, respectively, and via their alkali degradation at 407, 411, and 405 nm using an excitation wavelength of 310, 305, and 297 nm for CPD, CFX, and CPM determination, respectively. Linearity was achieved in the ranges of 0.35-3.50, 0.4-4.0, and 0.3-3.0 ?g/mL for the acid degradation products of CPD, CFX, and CPM, respectively, and in ranges of 0.05-0.5, 0.1-1.0, and 0.08-0.80 ?g/mL for the alkali degradation products of CPD, CFX, and CPM, respectively. The method was validated for various parameters according to International Conference on Harmonization guidelines. The method was successfully applied for the determination of these cephalosporin drugs in pharmaceutical dosage forms with good accuracy and precision. The results obtained by the proposed spectrofluorometric method were compared with good agreement to the official HPLC method. PMID:25905742

  7. Pesticide exposure and sprayer design: ergonomics evaluation to reduce pesticide

    E-print Network

    Pesticide exposure and sprayer design: ergonomics evaluation to reduce pesticide exposure Sonia of operator exposure to plant protection products through the introduction of ergonomics to the design process. It is suggested that a systematic ergonomics evaluation of sprayer interfaces with the view of reducing direct

  8. Pesticide biotransformation and fate in heterogeneous environments

    Microsoft Academic Search

    J. P. M. Vink

    1997-01-01

    The effects and relative impacts of environmental variables on the behaviour of pesticides, through the effect on pesticide-degrading microorganisms, was studied in a broad spectrum and covered the most relevant emission routes. It is shown that the effect of landscape geochemistry, which is a pre-set condition in an agricultural management, may be significant (chapter 2). Adjoining soil types, which occur

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

    USGS Publications Warehouse

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

    2000-01-01

    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.

  10. Toxicity of thermal degradation products of spacecraft materials

    NASA Technical Reports Server (NTRS)

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

    1982-01-01

    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.

  11. Study on degradation kinetics of 2-(2-hydroxypropanamido) benzoic acid in aqueous solutions and identification of its major degradation product by UHPLC/TOF-MS/MS.

    PubMed

    Zhang, Qili; Guan, Jiao; Rong, Rong; Zhao, Yunli; Yu, Zhiguo

    2015-08-10

    A RP-HPLC method was developed and validated for the degradation kinetic study of 2-(2-hydroxypropanamido) benzoic acid (HPABA), a promising anti-inflammatory drug, which would provide a basis for further studies on HPABA. The effects of pH, temperature, buffer concentration and ionic strength on the degradation kinetics of HPABA were discussed. Experimental parameters such as degradation rate constants (k), activation energy (Ea), acid and alkali catalytic constants (kac, kal), shelf life (t1/2) and temperature coefficient (Q10) were calculated. The results indicated that degradation kinetics of HPABA followed zero-order reaction kinetics; degradation rate constants (k) of HPABA at different pH values demonstrated that HPABA was more stable in neutral and near-neutral conditions; the function of temperature on k obeyed the Arrhenius equation (r=0.9933) and HPABA was more stable at lower temperature; with the increase of ionic strength and buffer concentration, the stability of HPABA was decreased. The major unknown degradation product of HPABA was identified by UHPLC/TOF-MS/MS with positive electrospray ionization. Results demonstrated that the hydrolysis product was the primary degradation product of HPABA and it was deduced as anthranilic acid. PMID:25935790

  12. Pesticide Residues in Food: Your Daily Dose.

    ERIC Educational Resources Information Center

    Mott, Lawrie

    1985-01-01

    Extensive use of pesticides during food production has created concerns for certain involuntary risks. Examines these concerns: government role in control and monitoring pesticide use, proposals for reform, and how consumer awareness might be an effective pressure for finding remedies. A table listing produce and pesticide residues is included.…

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

    PubMed

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

    2009-11-01

    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

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

    Microsoft Academic Search

    Kai Tuovinen; Heikki Paakkanen; Osmo Hänninen

    2001-01-01

    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

  15. The Effect on Rubbish Degradation and Leachate Production and Water Quality by Fillers Adding

    Microsoft Academic Search

    Yin Jun; Wu Xiaoyan; Jiang Baojun

    2010-01-01

    In order to study the effect of fillers with adsorption and drying on rubbish degradation, leachate production and water quality of leachate, five cylinder reactors for landfill disposal were built to simulate the operation of landfill, one reactor was used as contrast reactor, no filler added in it. Saw powder, activated carbon, zleolite and newspaper were added into another four

  16. Glucosinolate degradation products, alkanes and fatty acids from plants and cell cultures of Descurainia sophia

    Microsoft Academic Search

    S. Afsharypuor; G. B. Lockwood

    1985-01-01

    Allyl and 3-butenyl isothiocyanate with two nitriles and an epithiobutane derivative were estimated. These glucosinolate degradation products were found in callus, seed, and dried plant but not in suspension cultures. Seventeen alkanes and five fatty acids were also identified and estimated in plant material and cultures. 4-Methylthiobutyl and 2-phenylethyl isothiocyanates were also detected in seeds. Incubation of cultures at 4°

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

    Microsoft Academic Search

    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

    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,

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

    Microsoft Academic Search

    Jian Xu; Laosheng Wu; Andrew C. Chang

    2009-01-01

    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

  19. Fibrin degradation products in the serum and cerebrospinal fluid of patients with group A meningococcal meningitis

    Microsoft Academic Search

    M. J. Brueton; P. Tugwell; H. C. Whittle; B. M. Greenwood

    1974-01-01

    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

  20. Identification of a new degradation product of the antifouling agent Irgarol 1051 in natural samples

    USGS Publications Warehouse

    Ferrer, I.; Barcelo, D.

    2001-01-01

    A main degradation product of Irgarol [2-(methylthio)-4-(tert-butylamino)-6-(cyclopropylamino)-s-triazine], one of the most widely used compounds in antifouling paints, was detected at trace levels in seawater and sediment samples collected from several marinas on the Mediterranean coast. This degradation product was identified as 2-methylthio-4-tert-butylamino-s-triazine. The unequivocal identification of this compound in seawater samples was carried out by solid-phase extraction (SPE) coupled on-line with liquid chromatography-atmospheric pressure chemical ionization-mass spectrometry (LC-APCI-MS). SPE was carried out by passing 150 ml of seawater sample through a cartridge containing a polymeric phase (PLRP-s), with recoveries ranging from 92 to 108% (n=5). Using LC-MS detection in positive ion mode, useful structural information was obtained by increasing the fragmentor voltage, thus permitting the unequivocal identification of this compound in natural samples. Method detection limits were in the range of 0.002 to 0.005 ??g/l. Overall, the combination of on-line SPE and LC-APCI-MS represents an important advance in environmental analysis of herbicide degradation products in seawater, since it demonstrates that trace amounts of new polar metabolites may be determined rapidly. This paper reports the LC-MS identification of the main degradation product of Irgarol in seawater and sediment samples. ?? 2001 Elsevier Science B.V. All rights reserved.

  1. Derivatisation reactions in the chromatographic analysis of chemical warfare agents and their degradation products

    Microsoft Academic Search

    Robin M Black; Bob Muir

    2003-01-01

    The analysis of chemical warfare agents and their degradation products is an important component of verification of compliance with the Chemical Weapons Convention. Gas and liquid chromatography, particularly combined with mass spectrometry, are the major techniques used to detect and identify chemicals of concern to the Convention. The more polar analytes, and some of the more reactive or highly volatile

  2. In vitro cytotoxic and genotoxic effects of diphenylarsinic acid, a degradation product of chemical warfare agents

    Microsoft Academic Search

    Takafumi Ochi; Toshihide Suzuki; Hideo Isono; Toshikazu Kaise

    2004-01-01

    Diphenylarsinic acid [DPAs(V)], a degradation product of diphenylcyanoarsine or diphenylchloroarsine, both of which were developed as chemical warfare agents, was investigated in terms of its capacity to induce cytotoxic effects, numerical and structural changes of chromosomes, and abnormalities of centrosome integrity and spindle organizations in conjunction with the effects of glutathione (GSH) depletion. DPAs(V) had toxic effects on cultured human

  3. A new method for production of valienamine with microbial degradation of acarbose.

    PubMed

    Chen, Xiaolong; Zheng, Yuguo; Shen, Yinchu

    2005-01-01

    A new method for the production of valienamine with the microbial degradation of acarbose is described. The microorganism was screened by our laboratory and identified as Stenotrophomonas maltrophilia. After separation, valienamine was analyzed with UV, IR, and 1H and 13C NMR. The yield was more than 60%. PMID:15932287

  4. Resource degradation, technical change, and the productivity of energy use in U.S. agriculture

    Microsoft Academic Search

    Cutler J. Cleveland

    1995-01-01

    Two important issues surrounding future food production are the reliance of industrial agriculture on large quantities of fossil fuels and the degree to which technical change and farm management can offset degradation in the form of soil erosion, groundwater depletion, reduced genetic diversity, pest resistance, and so on. This analysis uses new and more consistent data on energy use in

  5. The NIOSH Retrospective Pesticide Reference Database.

    PubMed

    Ruder, A M; Butler, M A; Sanderson, W T; Carreón, T; Waters, M A; Zivkovich, Z E

    2009-04-01

    For the National Institute for Occupational Safety and Health (NIOSH) case-control study of glioma among non-metropolitan residents, pesticide information was considered critical. Responses to open-ended questions about pesticide exposures had to be grouped for analysis. Our aim was to classify pesticide responses in biologically relevant categories. We built the NIOSH Retrospective Pesticide Reference Database (NIOSH-RPRD) on over 1000 pesticide products and chemicals, particularly those likely to be used in the upper Midwest, using multiple sources. We obtained first and last years of product registration and product pesticide ingredients and their relative weights from the U.S. Environmental Protection Agency's Pesticide Product Information System. We added fields for pesticide class (organophosphate, etc.), carcinogenicity ratings, and evidence regarding endocrine-disrupting activity. Participant data were merged with the database, allowing each product recalled by a respondent to be linked to one or more chemicals, as appropriate. Respondents named 1347 different pesticides (or pesticide-targeted species) used on the farm, at non-farm jobs, or at home. Database usefulness was assessed by comparing numbers of responses naming actual chemicals to total responses linked to those chemicals. Sixty percent of farm pesticide, 59% of non-farm occupational, and 65% of house and garden responses named products, not chemicals. Among farm pesticide users, 182 (46%) reported using a total of 440 pesticides 1 to 40 years (mean 8.5 years) before those pesticides actually were marketed. The NIOSH-RPRD, now available to other investigators, has been a useful tool for us and other researchers to evaluate, group, and correct pesticide responses. PMID:19496343

  6. Effect of exogenous xylanase on rumen in vitro gas production and degradability of wheat straw.

    PubMed

    Togtokhbayar, Norovsambuu; Cerrillo, María A; Rodríguez, Germán Buendía; Elghandour, Mona M M Y; Salem, Abdelfattah Z M; Urankhaich, Chuluunbaatar; Jigjidpurev, Sukhbaatar; Odongo, Nicholas E; Kholif, Ahmed E

    2015-08-01

    The objective of this study was to determine effects of xylanase on in vitro gas production (GP) and in sacco degradability of wheat straw. Rumen fluid was obtained from three Mongolian native goats fitted with permanent rumen cannulas. The trial consisted of five doses (0, 0.5, 1.0, 1.5, 2.0??L/g of substrate) of a commercial xylanase (Dyadic(®) xylanase PLUS, Dyadic International, Inc., Jupiter, FL, USA). For the in sacco degradability, different levels of xylanase enzyme were added directly onto 2?g of wheat straw in nylon bags and incubated in the rumen for 3, 6, 12, 24 and 48?h to estimate degradability of wheat straw. Total GP increased (P?production had a similar pattern at 3 and 12?h of incubation; increased linearly at 24?h of incubation, and was unaffected at 6 and 48?h of incubation. Rumen NH3 -N concentration increased linearly at 3?h and the highest values were observed with intermediate enzyme levels. All ruminal volatile fatty acids increased linearly with intermediate levels of the fibrolytic enzyme. The in sacco rate of dry matter degradation decreased linearly (P?=?0.020) with increasing enzymes. Intermediate levels of xylanase improved rumen kinetic fermentation and degradability. The outcome of this research indicated that the application of xylanase enzyme could improve in vitro?GP fermentation of wheat straw. PMID:25923062

  7. Degradation of trichloronitromethane by iron water main corrosion products.

    PubMed

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

    2008-04-01

    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

  8. Concentrations of selected chlorinated pesticides in shrimp collected from the Calcasieu River/Lake Complex, Louisiana

    SciTech Connect

    Murray, H.E.; Beck, J.N. (McNeese State Univ., Lake Charles, LA (USA))

    1990-05-01

    For several decades inland and coastal aquatic ecosystems have been affected by a multitude of synthetic chemical substances. This is a consequence of population growth and increased industrial and agricultural activity. Many of these chemicals, the by-products of their production, and degradation products ultimately find their way into the aquatic environment as pollutants. The extent to which these pollutants affect the environment and its inhabitants depends largely upon the quantity and nature of the particular compounds involved. Halogenated hydrocarbons, particularly polychlorinated biphenyls (PCBs), and the pesticide DDT and its degradation products have received much attention as environmental pollutants. Because of the economic importance of the shrimping industry to southwest Louisiana, the objective of this study was to analyze shrimp collected from the Calcasieu River/Lake Complex for the presence of selected chlorinated pesticides. The presence of these compounds within shrimp tissues would serve as an indicator for the extent of pollution throughout this important estuarine system.

  9. Spatial modeling of personalized exposure dynamics: the case of pesticide use in small-scale agricultural production landscapes of the developing world

    PubMed Central

    Leyk, Stefan; Binder, Claudia R; Nuckols, John R

    2009-01-01

    Background Pesticide poisoning is a global health issue with the largest impacts in the developing countries where residential and small-scale agricultural areas are often integrated and pesticides sprayed manually. To reduce health risks from pesticide exposure approaches for personalized exposure assessment (PEA) are needed. We present a conceptual framework to develop a spatial individual-based model (IBM) prototype for assessing potential exposure of farm-workers conducting small-scale agricultural production, which accounts for a considerable portion of global food crop production. Our approach accounts for dynamics in the contaminant distributions in the environment, as well as patterns of movement and activities performed on an individual level under different safety scenarios. We demonstrate a first prototype using data from a study area in a rural part of Colombia, South America. Results Different safety scenarios of PEA were run by including weighting schemes for activities performed under different safety conditions. We examined the sensitivity of individual exposure estimates to varying patterns of pesticide application and varying individual patterns of movement. This resulted in a considerable variation in estimates of magnitude, frequency and duration of exposure over the model runs for each individual as well as between individuals. These findings indicate the influence of patterns of pesticide application, individual spatial patterns of movement as well as safety conditions on personalized exposure in the agricultural production landscape that is the focus of our research. Conclusion This approach represents a conceptual framework for developing individual based models to carry out PEA in small-scale agricultural settings in the developing world based on individual patterns of movement, safety conditions, and dynamic contaminant distributions. The results of our analysis indicate our prototype model is sufficiently sensitive to differentiate and quantify the influence of individual patterns of movement and decision-based pesticide management activities on potential exposure. This approach represents a framework for further understanding the contribution of agricultural pesticide use to exposure in the small-scale agricultural production landscape of many developing countries, and could be useful to evaluate public health intervention strategies to reduce risks to farm-workers and their families. Further research is needed to fully develop an operational version of the model. PMID:19331690

  10. Assessing pesticide leaching under climate change: The role of climate input uncertainty

    NASA Astrophysics Data System (ADS)

    Steffens, Karin; Larsbo, Mats; Moeys, Julien; Jarvis, Nicholas J.; Kjellström, Erik; Lewan, Elisabet

    2013-04-01

    Pesticide leaching from arable land constitutes a potential risk for contamination of ground and surface waters. Degradation and transport of pesticides in arable soils are influenced by both soil type, compound properties and application timings and are also strongly linked to weather and climate such as temperature and rainfall patterns. The assessment of pesticide leaching under climate change can give early indications of possible changes in pesticide leaching risks of importance for water pollution and serve as a basis for decision-making regarding the use of pesticides. Such an assessment requires detailed analyses of different sources of uncertainty that influence the results. The aim of this study was to assess the uncertainty related to climate scenario input data and to compare this to the parameter uncertainty of the pesticide leaching model. Furthermore, the influence of the choice of application timing on the leaching results was investigated. We used a modified version of the pesticide leaching model MACRO5.2 that included both temperature dependent sorption and diffusion. The calibration of the model to a one-year field data set for a clay soil in South-West Sweden led to 56 equally acceptable parameter sets representing the parameter uncertainty for that soil. Nine different climate model projections of the regional climate model RCA3 (Swedish Meteorological and Hydrological Institute) were available as driven by different combinations of global circulation model (GCM), greenhouse gas emission scenarios, and initial states of the GCM. The future time series used to drive the MACRO-model were generated by perturbing a reference climate data set (1970-1999) for an important agricultural production area in South-West Sweden based on monthly change factors for 2070-2099. Scenario predictions for different pesticide properties and application seasons were performed. Our analysis showed that pesticide leaching was sensitive to changes in both rainfall amounts and temperatures in periods that are critical for pesticide losses from drained clay soils in Sweden (spring and autumn) and to the choice of the pesticide application date. The choice of a specific climate model projection could not only change the magnitude of the predicted future losses but also the direction of change independent from pesticide properties and application season and thus, strongly influence our estimations of future changes in pesticide leaching risks and thereby linked threats to surface water quality. Although the parameter uncertainty was relatively large, 50 to 80% of the different parameter sets predicted a similar change in pesticide leaching losses from present to future, which underlined the impact of climate input uncertainty on the results.

  11. Separation and identification of some chemical warfare degradation products using electrospray high resolution ion mobility spectrometry with mass selected detection

    Microsoft Academic Search

    G. Reid Asbury; Ching Wu; William F Siems; Herbert H Hill

    2000-01-01

    High resolution electrospray ion mobility spectrometry (IMS) was used to analyze chemical warfare degradation products from liquid samples. For each degradation product analytical figures of merit for the technique were determined and each response ion was identified by mass spectrometry. From these data, reduced mobility constants (K0) for a number of compounds were calculated for the first time. The detection

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

    PubMed

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

    2007-07-25

    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

  13. Chemical and photochemical degradation of chlorantraniliprole and characterization of its transformation products.

    PubMed

    Lavtižar, Vesna; van Gestel, Cornelis A M; Dolenc, Darko; Trebše, Polonca

    2014-01-01

    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

  14. Repression and Recuperation of Brood Production in Bombus terrestris Bumble Bees Exposed to a Pulse of the Neonicotinoid Pesticide Imidacloprid

    PubMed Central

    Laycock, Ian; Cresswell, James E.

    2013-01-01

    Currently, there is concern about declining bee populations and some blame the residues of neonicotinoid pesticides in the nectar and pollen of treated crops. Bumble bees are important wild pollinators that are widely exposed to dietary neonicotinoids by foraging in agricultural environments. In the laboratory, we tested the effect of a pulsed exposure (14 days ‘on dose’ followed by 14 days ‘off dose’) to a common neonicotinoid, imidacloprid, on the amount of brood (number of eggs and larvae) produced by Bombus terrestris L. bumble bees in small, standardised experimental colonies (a queen and four adult workers). During the initial ‘on dose’ period we observed a dose-dependent repression of brood production in colonies, with productivity decreasing as dosage increased up to 98 µg kg?1 dietary imidacloprid. During the following ‘off dose’ period, colonies showed a dose-dependent recuperation such that total brood production during the 28-day pulsed exposure was not correlated with imidacloprid up to 98 µg kg?1. Our findings raise further concern about the threat to wild bumble bees from neonicotinoids, but they also indicate some resilience to a pulsed exposure, such as that arising from the transient bloom of a treated mass-flowering crop. PMID:24224015

  15. Ethanol production by Saccharomyces cerevisiae using lignocellulosic hydrolysate from Chrysanthemum waste degradation.

    PubMed

    Quevedo-Hidalgo, Balkys; Monsalve-Marín, Felipe; Narváez-Rincón, Paulo César; Pedroza-Rodríguez, Aura Marina; Velásquez-Lozano, Mario Enrique

    2013-03-01

    Ethanol production derived from Saccharomyces cerevisiae fermentation of a hydrolysate from floriculture waste degradation was studied. The hydrolysate was produced from Chrysanthemum (Dendranthema grandiflora) waste degradation by Pleurotus ostreatus and characterized to determine the presence of compounds that may inhibit fermentation. The products of hydrolysis confirmed by HPLC were cellobiose, glucose, xylose and mannose. The hydrolysate was fermented by S. cerevisiae, and concentrations of biomass, ethanol, and glucose were determined as a function of time. Results were compared to YGC modified medium (yeast extract, glucose and chloramphenicol) fermentation. Ethanol yield was 0.45 g g(-1), 88 % of the maximal theoretical value. Crysanthemum waste hydrolysate was suitable for ethanol production, containing glucose and mannose with adequate nutrients for S. cerevisiae fermentation and low fermentation inhibitor levels. PMID:23117675

  16. Rates and products of degradation for MTBE and other oxygenate fuel additives in the subsurface environment

    SciTech Connect

    Tratnyek, P.G.; Church, C.D.; Pankow, J.F. [Oregon Graduate Inst., Portland, OR (United States). Dept. of Environmental Science and Engineering

    1995-12-31

    The recent realization that oxygenated fuel additives such as MTBE are becoming widely distributed groundwater contaminants has created a sudden and pressing demand for data on the processes that control their environmental fate. Explaining and predicting the subsequent environmental fate of these compounds is going to require extrapolations over long time frames that will be very sensitive to the quality of input data on each compound. To provide such data, they have initiated a systematic study of the pathways and kinetics of fuel oxygenate degradation under subsurface conditions. Batch experiments in simplified model systems are being performed to isolate specific processes that may contribute to MTBE degradation. A variety of degradation pathways can be envisioned that lead to t-butyl alcohol (TBA) as the primary or secondary product. However, experiments to date with a facultative iron reducing bacteria showed no evidence for TBA formation. Continuing experiments include mixed cultures from a range of aquifer materials representative of NAWQA study sites.

  17. Penetration of hydrogen peroxide and degradation rate of different bleaching products.

    PubMed

    Marson, F C; Gonçalves, R S; Silva, C O; Cintra, L T Â; Pascotto, R C; Santos, P H Dos; Briso, A L F

    2015-01-01

    This study's aim was to evaluate the degradation rate of hydrogen peroxide (H2O2) and to quantify its penetration in tooth structure, considering the residence time of bleaching products on the dental enamel. For this study, bovine teeth were randomly divided according to the bleaching product received: Opalescence Xtra Boost 38%, White Gold Office 35%, Whiteness HP Blue 35%, Whiteness HP Maxx 35%, and Lase Peroxide Sensy 35%. To analyze the degradation of H2O2, the titration of bleaching agents with potassium permanganate was used, while the penetration of H2O2 was measured via spectrophotometric analysis of the acetate buffer solution, collected from the artificial pulp chamber. The analyses were performed immediately as well as 15 minutes, 30 minutes, and 45 minutes after product application. The data of degradation rate of H2O2 were submitted to analysis of variance (ANOVA) and Tukey tests, while ANOVA and Fisher tests were used for the quantification of H2O2, at the 5% level. The results showed that all products significantly reduced the concentration of H2O2 activates at the end of 45 minutes. It was also verified that the penetration of H2O2 was enhanced by increasing the residence time of the product on the tooth surface. It was concluded that the bleaching gels retained substantial concentrations of H2O2 after 45 minutes of application, and penetration of H2O2 in the dental structure is time-dependent. PMID:24828134

  18. Biodegradation of the Alkaline Cellulose Degradation Products Generated during Radioactive Waste Disposal

    PubMed Central

    Rout, Simon P.; Radford, Jessica; Laws, Andrew P.; Sweeney, Francis; Elmekawy, Ahmed; Gillie, Lisa J.; Humphreys, Paul N.

    2014-01-01

    The anoxic, alkaline hydrolysis of cellulosic materials generates a range of cellulose degradation products (CDP) including ? and ? forms of isosaccharinic acid (ISA) and is expected to occur in radioactive waste disposal sites receiving intermediate level radioactive wastes. The generation of ISA's is of particular relevance to the disposal of these wastes since they are able to form complexes with radioelements such as Pu enhancing their migration. This study demonstrates that microbial communities present in near-surface anoxic sediments are able to degrade CDP including both forms of ISA via iron reduction, sulphate reduction and methanogenesis, without any prior exposure to these substrates. No significant difference (n?=?6, p?=?0.118) in ? and ? ISA degradation rates were seen under either iron reducing, sulphate reducing or methanogenic conditions, giving an overall mean degradation rate of 4.7×10?2 hr?1 (SE±2.9×10?3). These results suggest that a radioactive waste disposal site is likely to be colonised by organisms able to degrade CDP and associated ISA's during the construction and operational phase of the facility. PMID:25268118

  19. Non-UV light influences the degradation rate of crop protection products.

    PubMed

    Davies, Lawrence O; Bramke, Irene; France, Emma; Marshall, Samantha; Oliver, Robin; Nichols, Carol; Schäfer, Hendrik; Bending, Gary D

    2013-08-01

    Crop protection products (CPPs) are subject to strict regulatory evaluation, including laboratory and field trials, prior to approval for commercial use. Laboratory tests lack environmental realism, while field trials are difficult to control. Addition of environmental complexity to laboratory systems is therefore desirable to mimic a field environment more effectively. We investigated the effect of non-UV light on the degradation of eight CPPs (chlorotoluron, prometryn, cinosulfuron, imidacloprid, lufenuron, propiconazole, fludioxonil, and benzovindiflupyr) by addition of non-UV light to standard OECD 307 guidelines. Time taken for 50% degradation of benzovindiflupyr was halved from 373 to 183 days with the inclusion of light. Similarly, time taken for 90% degradation of chlorotoluron decreased from 79 to 35 days under light conditions. Significant reductions in extractable parent compound occurred under light conditions for prometryn (4%), imidacloprid (8%), and fludioxonil (24%) compared to dark controls. However, a significantly slower rate of cinosulfuron (14%) transformation was observed under light compared to dark conditions. Under light conditions, nonextractable residues were significantly higher for seven of the CPPs. Soil biological and chemical analyses suggest that light stimulates phototroph growth, which may directly and/or indirectly impact CPP degradation rates. The results of this study strongly suggest that light is an important parameter affecting CPP degradation, and inclusion of light into regulatory studies may enhance their environmental realism. PMID:23819841

  20. Sustainable agricultural practices: energy inputs and outputs, pesticide, fertilizer and greenhouse gas management.

    PubMed

    Wang, Yue-Wen

    2009-01-01

    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

  1. Identification and functional characteristics of chlorpyrifos-degrading and plant growth promoting bacterium Acinetobacter calcoaceticus.

    PubMed

    Zhao, Lei; Wang, Fei; Zhao, Jiao

    2014-05-01

    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

  2. Method for determination of methyl tert-butyl ether and its degradation products in water

    USGS Publications Warehouse

    Church, C.D.; Isabelle, L.M.; Pankow, J.F.; Rose, D.L.; Tratnyek, P.G.

    1997-01-01

    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.

  3. Obsolete pesticides

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    Several hundred tons of obsolete pesticide stocks worldwide will pose a threat to humans and the environment until the year 2030 in some regions, unless funding for waste disposal is significantly increased, the United Nations Food and Agriculture Organization (FAO) said in a message directed to donor governments and industry on May 24.“Deadly chemicals are contaminating the soils, groundwater, irrigation, and drinking water,” said Amemayehu Wodageneh, senior expert on obsolete pesticides for FAO. “These ‘forgotten’ stocks are a serious risk, [and] they could cause an environmental tragedy in rural areas and big cities. There is hardly any developing country that is not affected by the hazards of obsolete pesticides.”

  4. Fate of CL-20 in sandy soils: degradation products as potential markers of natural attenuation.

    PubMed

    Monteil-Rivera, Fanny; Halasz, Annamaria; Manno, Dominic; Kuperman, Roman G; Thiboutot, Sonia; Ampleman, Guy; Hawari, Jalal

    2009-01-01

    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

  5. Bacterial degradation of chlorophenols and their derivatives

    PubMed Central

    2014-01-01

    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

  6. Decontaminating pesticide protective clothing.

    PubMed

    Laughlin, J

    1993-01-01

    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

  7. Photo-assisted electrochemical detection (PAED) following HPLC-UV for the determination of nitro explosives and degradation products

    NASA Astrophysics Data System (ADS)

    Fedorowski, J.; LaCourse, William R.; Lorah, Michelle M.

    2012-06-01

    Continuous efforts implemented by government agencies such as the United States Geological Survey (USGS) aim to manage and protect the integrity of the environment's natural resources. RDX is one of the most frequently utilized nitramine explosives for mining, demolition and munitions purposes in the United States (US). The degradation of RDX in natural environments is of particular importance as a result of the accumulation of consequential degradation products in nature. Specifically, RDX has the potential to be degraded by microorganisms resulting in hazardous levels of harmful degradation products in soil and groundwater. The necessity for the detection of these particular degradation products is emphasized as a consequence of their toxicity as these products are recognized as potential mutagens. Photo-assisted electrochemical detection (PAED) following HPLC-UV is used to develop an analytical method qualified for the assessment of RDX and degradation products. The technique offers unique selectivity possessed by the photochemical reactor coupled to EC detection serving to eliminate the need for repetitive analysis using different column technologies. Furthermore, on-line sample pretreatment is developed and optimized specifically for the preparation of samples consisting of RDX and degradation products. Analytical figures of merit determined for all target analytes using on-line SPE-HPLC-UV-PAED revealed detection limits in the sub part per billion range for RDX and degradation product MEDINA. The effectiveness of the method is exemplified in collaborative studies with the USGS in monitoring the degradation of RDX and formation of degradation products once the nitro explosive is subject to anaerobic microorganisms WBC-2.

  8. Pesticide and metabolite fate, release and transport modelling at catchment scale

    NASA Astrophysics Data System (ADS)

    Gaßmann, Matthias; Olsson, Oliver; Bauer, Melanie

    2010-05-01

    Pesticides are of great concern in hydrological catchments all over the world. On the one hand they are necessary to guarantee stable agricultural production for an increasing population. On the other hand they endanger life of aquatic animals and freshwater resources. However, not only pesticides but also their degradation products, the metabolites, are toxic to the environment, in some cases even more than the parent material. Thus, it is necessary to optimize pesticide application and management of agricultural land (e.g. grass strips, erosion prevention) with respect and according to their behaviour and degradation in hydrological catchments. Modelling provides a sound tool for assessing the impacts of pesticide management changes on pesticide behaviour at the field and in consecutively surface waters. Most of the various models available in literature do not consider metabolism. This study introduces an applicable integrated model assessing the fate and release of a pesticide and one metabolite at the field and in surface waters of a hydrological catchment. For the development of the field release model, the single-equation pesticide release formula by the OECD (2000) was used, which combines sorption and degradation in one equation. The part of the equation calculating the degradation forms the input of a second OECD equation representing the metabolite with its own parameters. A fraction can be specified describing how much of the degradation product is transferred to the specific metabolite. The river network is simulated with a further development of the MOHID River Network model (MRN). The integration of a pesticide type and a metabolite, with their degradation and volatilization processes are the main improvements of the hydrodynamic channel model. Following, the combined model was set up to the Israeli part of the Upper Jordan River basin, especially the Hula valley. According to the local hydrological conditions, a linear storage with a threshold was applied to 26 subbasins as a hydrological base for the OECD equation. Virtually, 1000 kg of Chlorpyrifos were applied to the basin in two doses per year. The metabolite chosen in this test-application was TCP. The results showed pesticide and metabolite concentrations in the river at the catchment outlet in the expected order of magnitude. Field pesticide followed the application as Dirac-impulse with a subsequent exponential decay and lowering by overland flow removal. TCP field amounts, however, are a combination of two exponential equations resulting in a delayed, smaller and smoothed peak. The river network model showed its ability to simulate transport, mixture and mitigation of the pesticides. The test run showed the applicability of the new model chain to asses pesticide and metabolite release to surface waters in catchment systems, but has to be validated by measurements of those components. It is expected to gain these validation measurements in late 2010 by the project DYKE.

  9. 77 FR 59186 - Notice of Receipt of Pesticide Products; Registration Applications To Register New Uses

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-26

    ...Box 8025, Walnut Creek, CA 94596. Active ingredient: Clothianidin. Product Type: Insecticide. Proposed Uses: To amend an...Box 8025, Walnut Creek, CA 94596. Active ingredient: Clothianidin. Product Type: Insecticide. Proposed Uses:...

  10. 75 FR 8942 - Maneb; Product Cancellation Order for Certain Pesticide Registrations

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-26

    ...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...

  11. 75 FR 8340 - Maneb; Product Cancellation Order of a Certain Pesticide Registration

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-24

    ...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...

  12. 40 CFR 158.2171 - Experimental use permit microbial pesticides product analysis data requirements table.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...Substance MP EP Test Notes Product Chemistry and Composition 885.1100 Product...Certification of limits R MP EP -- Physical and Chemical Characteristics 830... R TGAI TGAI -- 830.6303 Physical state R TGAI TGAI --...

  13. 40 CFR 158.2120 - Microbial pesticides product analysis data requirements table.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...Substance MP EP Test Notes Product Chemistry and Composition 885.1100 Product...Certification of limits R MP EP -- Physical and Chemical Characteristics 830... R TGAI TGAI -- 830.6303 Physical state R TGAI TGAI --...

  14. 40 CFR 158.2171 - Experimental use permit microbial pesticides product analysis data requirements table.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...Substance MP EP Test Notes Product Chemistry and Composition 885.1100 Product...Certification of limits R MP EP -- Physical and Chemical Characteristics 830... R TGAI TGAI -- 830.6303 Physical state R TGAI TGAI --...

  15. 40 CFR 158.2171 - Experimental use permit microbial pesticides product analysis data requirements table.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...Substance MP EP Test Notes Product Chemistry and Composition 885.1100 Product...Certification of limits R MP EP -- Physical and Chemical Characteristics 830... R TGAI TGAI -- 830.6303 Physical state R TGAI TGAI --...

  16. 40 CFR 158.2120 - Microbial pesticides product analysis data requirements table.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...substance MP EP Test notes Product Chemistry and Composition 885.1100 Product...Certification of limits R MP EP Physical and Chemical Characteristics 830.6302 Color R TGAI TGAI 830.6303 Physical state R TGAI TGAI...

  17. 40 CFR 158.2171 - Experimental use permit microbial pesticides product analysis data requirements table.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...substance MP EP Test notes Product Chemistry and Composition 885.1100 Product...Certification of limits R MP EP Physical and Chemical Characteristics 830.6302 Color R TGAI TGAI 830.6303 Physical state R TGAI TGAI...

  18. 40 CFR 158.2120 - Microbial pesticides product analysis data requirements table.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...substance MP EP Test notes Product Chemistry and Composition 885.1100 Product...Certification of limits R MP EP Physical and Chemical Characteristics 830.6302 Color R TGAI TGAI 830.6303 Physical state R TGAI TGAI...

  19. 40 CFR 158.2171 - Experimental use permit microbial pesticides product analysis data requirements table.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...substance MP EP Test notes Product Chemistry and Composition 885.1100 Product...Certification of limits R MP EP Physical and Chemical Characteristics 830.6302 Color R TGAI TGAI 830.6303 Physical state R TGAI TGAI...

  20. Synergistic collaboration of gut symbionts in Odontotermes formosanus for lignocellulosic degradation and bio-hydrogen production.

    PubMed

    Mathew, Gincy Marina; Mathew, Dony Chacko; Lo, Shou-Chen; Alexios, Georgy Mathew; Yang, Jia-Cih; Sashikumar, Jagathala Mahalingam; Shaikh, Tanveer Mahamadali; Huang, Chieh-Chen

    2013-10-01

    In this work, gut microbes from the macrotermitine termite Odontotermes formosanus the cellulolytic Bacillus and fermentative Clostridium were studied in batch experiments using different carbon substrates to bio-mimic the termite gut for hydrogen production. Their fungus comb aging and the in vitro lignocellulosic degradation of the mango tree substrates by the synergistic interaction of Bacillus, Clostridium and Termitomyces were detected by Solid-state NMR. From the results, Bacillus species acted as a mutualist, by initiating an anaerobic environment for the growth of Clostridium, for bio-hydrogen production and the presence of Termitomyces enhanced the lignocellulosic degradation of substrates in vitro and in vivo. Thus, the synergistic collaboration of these three microbes can be used for termite-derived bio-fuel processing technology. PMID:23298769

  1. 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. ...

  2. 77 FR 72342 - Notice of Receipt of Pesticide Products; Registration Applications

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-05

    ...entities may include: Crop production (NAICS code 111). Animal production (NAICS code 112). Food...chloro-4-nitro-1H-pyrazol-3-yl)-methanol (CHNP) at 96.5%. Product...chloro-4-nitro-1H-pyrazol-3-yl)-methanol (CHNP) at17%....

  3. Glucosinolate degradation products, alkanes and fatty acids from plants and cell cultures of Descurainia sophia.

    PubMed

    Afsharypuor, S; Lockwood, G B

    1985-12-01

    Allyl and 3-butenyl isothiocyanate with two nitriles and an epithiobutane derivative were estimated. These glucosinolate degradation products were found in callus, seed, and dried plant but not in suspension cultures. Seventeen alkanes and five fatty acids were also identified and estimated in plant material and cultures. 4-Methylthiobutyl and 2-phenylethyl isothiocyanates were also detected in seeds. Incubation of cultures at 4° increased levels of the fatty acids but not isothiocyanates. PMID:24254078

  4. Cytotoxicities of ginseng saponins and their degradation products against some cancer cell lines

    Microsoft Academic Search

    Nam-In Baek; Dong Seon Kim; You Hui Lee; Jong Dae Park; Chun Bae Lee; Shin Il Kim

    1995-01-01

    In order to elucidate the cytotoxicity-structure correlation of ginseng-derived components, several prosapogenins and sapogenins\\u000a were prepared from Korean red ginseng (Panax ginseng) saponins by acid hydrolysis or alkaline cleveage, and their chemical structures were identified by a combination of spectral\\u000a and physical methods. Some of these degradation products showed the cytotoxic activities against various cancer cell lines,\\u000a A549, SK-OV-3, SK-Mel-2,

  5. Production of tannase from wood-degrading fungus using as substrate plant residues: purification and characterization

    Microsoft Academic Search

    R. M. Ordoñez; I. Colombo; M. R. Alberto; M. I. Isla

    In the present study Lenzites elegans, Schizophyllum commune, Ganoderma applanatum and Pycnoporus sanguineus (wood-degrading fungi) were assayed for their tannase producing potential in culture media containing plant residues or\\/and\\u000a tannic acid as carbon source. Aspergillus niger was used as positive control for tannase production. We also carried out the isolation, purification and characterization\\u000a of the enzyme from the fungi selected

  6. Analytical modeling of degradation product partitioning kinetics in source zones containing entrapped DNAPL

    Microsoft Academic Search

    C. Andrew Ramsburg; John A. Christ; Scott R. Douglas; Ali Boroumand

    2011-01-01

    Liquid-liquid equilibrium experiments indicate that there is a strong thermodynamic driving force for the reversible sequestration of cis-dichloroethene (DCE) within microbially active dense nonaqueous phase liquid (DNAPL) source zones containing chlorinated ethene solvents. Assessment of the importance of degradation product sequestration, however, requires accurate description of the mass transfer kinetics. Partitioning kinetics of cis-DCE were assessed in a series of

  7. The analysis of sterol degradation products to detect vegetable fats in chocolate

    Microsoft Academic Search

    C. Crews; R. Calvet-Sarrett; P. Brereton

    1997-01-01

    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

  8. Microbially Mediated Degradation of Common Pharmaceuticals and Personal Care Products in Soil Under Aerobic and Reduced Oxygen Conditions

    Microsoft Academic Search

    Deborah L. Carr; Audra N. Morse; John C. Zak; Todd A. Anderson

    2011-01-01

    Biological degradation rates of estrogen compounds and common pharmaceutical and personal care products (PPCPs) were examined\\u000a in soils with a long history of exposure to these compounds through wastewater effluent and in soil not previously exposed.\\u000a Biological degradation rates over 14 days were compared under aerobic and anaerobic conditions. Estrogen compounds including\\u000a estrone, 17?-estradiol, estriol, and 17?-ethinylestradiol exhibited rapid degradation by

  9. Pesticide residues in commercially available oranges and evaluation of potential washing methods

    Microsoft Academic Search

    Anneli Kruvea; Andrea Lamos; Jekaterina Kirillova; Koit Herodes

    Pesticides, which are widely used in agriculture to increase production or protect crop, are known to be potentially dangerous to consumers. Therefore oranges from local supermarket were analysed by the LC-ESI-MS method to determine the presence of pesticides. Two pesticides - thiabendazole and imazalil - were found in the oranges. Both are post-harvest pesticides. Analyses showed that these pesticides are

  10. Degradation products of 2,4,6-Trinitrotoluene by a microbial consortia

    SciTech Connect

    Ortiz, O.; Parker, C.; Bender, J. [Clark Atlanta Univ., Atlanta, GA (United States)] [and others

    1995-12-01

    Remediation of contaminated soils can be accomplished using microbial species. Of particular interest is the remediation of explosive contaminated soils. A microbial consortia has been developed which removes TNT by an unexplained mechanism. Our goal is to understand the degradation of TNT by this microbial mat. Constructed mats have been generated in our laboratory by enriching water with ensiled grass and adding specific microbial components for organic degradation. Microbial mats are natural mixed microbial communities dominated by cyanobacterias (blue-green algae). In this research, degradation products of TNT have been identified using GC/MS. Ninety-seven percent of TNT (1000 mg/L), was removed in < 1 day by floating mats placed over TNT-contaminated water in quiescent ponds. Metabolites of TNT, 2, 4-Dinitro-6 amminotoluene and 2-Nitro-4,6 diaminotoluene has been observed after 1 day of mat treatment. A mechanism is postulated for this degradation showing that two of the nitro groups of the TNT molecule are being reduced to amino groups systematically. Anoxic zones in the mat, containing sulfur-reducing bacteria, may account for the reduction of TNT. GC/MS shows significant decreases in metabolite concentrations in 4-7 days, indicating continued degradation of TNT. It has been found by toxicity assays that these metabolites appeared to be nontoxic and nonmutagenic. These results suggest that floating microbial mats may be useful for the decontamination of sites in the environment contaminated with TNT. Further studies using {sup 13}C TNT will focus on the fate of the carbon, to determine the intermediates products prior to transformations into hydrocarbons or utilization by the bacteria consortia.

  11. Analysis of environmental samples for explosives and explosives degradation products by liquid chromatography-mass spectrometry

    SciTech Connect

    Gates, P.M.; Furlong, E.T.; Lindley, C.E.; Burkhardt, M.R. [Geological Survey, Arvada, CO (United States). National Water Quality Lab.

    1994-12-31

    Nitroaromatic explosives and their degradation products are regulated water-soluble contaminants that may pose a hazard to human health and could be important water contaminants. The reliable identification of most explosives, in particular, the identification of degradation products, is a major shortcoming in most analytical methods. As an improvement, high-performance liquid chromatography (HPLC) (coupled to Thermospray) mass spectrometry was used to determine compound molecular weights, and tandem-mass spectrometry was applied to confirm molecular structure. Compounds were separated isocratically using methanol-water with an octadecylsilane HPLC column. The identities of known nitroaromatic explosives were confirmed by combined ultraviolet absorbance and negative ion mass spectra. For optimal detection of known compounds, selected ion monitoring mass spectrometry was used. Calibration curves fit quadratic models, with correlation coefficients typically exceeding 0.995 over two orders of magnitude. Instrument detection limits ranged from 2.5 to 10 nanograms per injection, resulting in method-detection limits from about 100 to 400 nanograms per liter for a typical water sample. Unknown analytes (indicated by optical spectra) were identified by full scan and tandem mass spectrometry experiments on sample extracts or isolated extract fractions. This combined ultraviolet-diode array mass spectrometric approach is a superior method for analyzing soil or water samples where known explosives and unknown degradation products might be present.

  12. Utilization of Ganglioside-Degrading Paenibacillus sp. Strain TS12 for Production of Glucosylceramide

    PubMed Central

    Sumida, Tomomi; Sueyoshi, Noriyuki; Ito, Makoto

    2002-01-01

    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. PMID:12406710

  13. DEVELOPMENT OF A PRODUCT MODEL FOR CUT-AND-COVER TUNNELS INCLUDING DEGRADATIONS

    NASA Astrophysics Data System (ADS)

    Aruga, Takashi; Yabuki, Nobuyoshi; Arai, Yasushi

    Cut-and-Cover tunnels are constructed on site. The various conditions of environments and techniques of construction make a significant influence on the quality of the tunnel. It is extremely difficult to rebuild the tunnel even if a structural trouble is found once the construction is completed. Thus, suitable maintenance is needed to ensure the tunnel is in a healthy condition. To execute better maintenance, the information on design and construction of the tunnel is vital for inspection of degradation, estimation of occurrence factors and planning of repair or refurbishing works. In this paper, we developed a product model for representing cut-and-cover tunnels including degradations for effective information use in maintenance work. As its first step, we investigated the characteristics of cut-and-cover tunnels and degradations about reinforced concrete members and developed a conceptual model. Then, we implemented the conceptual product model by expanding Industry Foundation Classes (IFC). Finally, we verified the product model by applying it to a simple tunnel.

  14. 77 FR 59190 - Halofenozide; Notice of Receipt of Requests To Voluntarily Cancel Pesticide Registrations and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-26

    ...Pesticide Registrations and Terminate All Uses AGENCY: Environmental Protection...voluntarily cancel pesticide registrations of all products containing the pesticide halofenozide. The requests would cancel all technical and end-use...

  15. On the Oxidative Degradation of Nadic End-Capped Polyimides. 3; Synthesis and Characterization of Model Compounds for End-Cap Degradation Products

    NASA Technical Reports Server (NTRS)

    Meador, Mary Ann B.; Johnston, J. Christopher; Frimer, Aryeh A.; Gilinsky-Sharon, Pessia

    1999-01-01

    The oxidative degradation of PMR (for polymerization of monomeric reactants) polyimides at elevated temperatures was followed by cross-polarized magic angle spinning (CP-MAS) NMR. Labeling of selected sites in the polymers with C-13 allowed for direct observation of the transformations arising from oxidation processes. The formation of several degradation products has been proposed to be occurring in the cross-links derived from the nadic end caps on oxidation. Model compounds have been synthesized and characterized by CPMAS NMR with both normal and delayed decoupling to distinguish between protonated and unprotonated carbons. Comparison of these spectra to predicted chemical shifts of proposed products for the aged polymer provides further insight to degradation occurring in the cross-linked moieties.

  16. Amine-degradation products play no part in corrosion at gas-sweetening plants

    SciTech Connect

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

    1982-11-15

    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.

  17. Interaction between vine pesticides and bovine serum albumin studied by nuclear spin relaxation data.

    PubMed

    Martini, Silvia; Bonechi, Claudia; Rossi, Claudio

    2010-10-13

    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

  18. Identification of degradation products of antioxidants in polyolefins by liquid chromatography combined with atmospheric pressure photoionisation mass spectrometry

    Microsoft Academic Search

    Eva Reingruber; Markus Himmelsbach; Christian Sauer; Wolfgang Buchberger

    2010-01-01

    Round robin tests have revealed the trend that the concentration of stabilizers in polyolefins is usually underestimated. However, it is still unclear whether this underestimation is due to systematic errors of the analysis procedures or to degradation of the stabilizers during the production of the round robin sample itself. Within the present work, the degradation pathways of six common antioxidants

  19. Conditions for collection of serum samples for the measurement of fibrin(ogen) degradation products by radioimmunoassay of fragment E

    Microsoft Academic Search

    M J Martin; Y B Gordon; S M Ratky; L R Baker; T Chard

    1976-01-01

    A number of conditions have been assessed for the collection of serum samples for the measurement of fibrin(ogen) degradation products using a radioimmunoassay for degradation fragment E, which permits precise quantitation of differences. Blood should be collected using minimal venous occlusion into glass tubes containing 10 mg\\/ml of epsilon amino caproic acid and allowed to clot at 4 to 20

  20. Impact of Heme and Heme Degradation Products on Vascular Diameter in Mouse Visual Cortex

    PubMed Central

    Joerk, Alexander; Seidel, Raphael Andreas; Walter, Sebastian Gottfried; Wiegand, Anne; Kahnes, Marcel; Klopfleisch, Maurice; Kirmse, Knut; Pohnert, Georg; Westerhausen, Matthias; Witte, Otto Wilhelm; Holthoff, Knut

    2014-01-01

    Background Delayed cerebral vasospasm is the most common cause of mortality and severe neurological impairment in patients who survive subarachnoid hemorrhage. Despite improvements in the field of diagnostic imaging, options for prevention and medical treatment—primarily with the calcium channel antagonist nimodipine or hemodynamic manipulations—are insufficient. Previous studies have suggested that heme and bilirubin oxidation end products, originating from degraded hemoglobin around ruptured blood vessels, are involved in the development of vasospasm by inhibiting large conductance BKCa potassium channels in vascular smooth muscle cells. In this study, we identify individual heme degradation products regulating arteriolar diameter in dependence of BKCa channel activity. Methods and Results Using differential interference contrast video microscopy in acute brain slices, we determined diameter changes of intracerebral arterioles in mouse visual cortex. In preconstricted vessels, the specific BKCa channel blockers paxilline and iberiotoxin as well as iron?containing hemin caused vasoconstriction. In addition, the bilirubin oxidation end product Z?BOX A showed a stronger vasoconstrictive potency than its regio?isomer Z?BOX B. Importantly, Z?BOX A had the same vasoconstrictive effect, independent of its origin from oxidative degradation or chemical synthesis. Finally, in slices of Slo1?deficient knockout mice, paxilline and Z?BOX A remained ineffective in changing arteriole diameter. Conclusions We identified individual components of the oxidative bilirubin degradation that led to vasoconstriction of cerebral arterioles. The vasoconstrictive effect of Z?BOX A and Z?BOX B was mediated by BKCa channel activity that might represent a signaling pathway in the occurrence of delayed cerebral vasospasm in subarachnoid hemorrhage patients. PMID:25169792

  1. Amine Degradation in CO2 Capture. 2. New degradation products of MEA. Pyrazine and alkyl pyrazines: analysis, mechanism of formation and toxicity.

    E-print Network

    Paris-Sud XI, Université de

    degradation products, and some of them could be potentially dangerous to humans or environment according in a pilot plant sample. A mechanism for their formation was proposed. The toxicity of these molecules was assessed based on available toxicological data and, when the information was not sufficient

  2. Stability-indicating determination of rebamipide in the presence of its acid degradation products.

    PubMed

    Abbas, Samah S; Zaazaa, Hala E; Essam, Hebat Allah M; El-Bardicy, Mohammed G

    2014-01-01

    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-densitometric procedure in which REB was separated from its degradation products using a developing solution of methanol-chloroform-ammonia (8.5 + 1.5 + 0.5, v/v/v). The quantitative evaluation of REB at 329 nm was linear over the concentration range of 0.50-4.5 microg/band, with a mean recovery of 99.49 +/- 0.99% even in the presence of up to 90% degradation products. Method D is an RP-HPLC procedure. It provided the complete separation of REB from its degradation products on an Xterra C18 column using phosphate buffer (pH 6, 0.01 M)-methanol (1 + 1, v/v) as the mobile phase (UV detection at 254 nm). Recovery was 99.28 +/- 0.78% within the range of 10-190 microg/mL. The selectivity of the proposed methods was checked using laboratory-prepared mixtures. The proposed methods have been successfully applied to the analysis of REB in pharmaceutical dosage forms without interference from other dosage form excipients. PMID:24672862

  3. Phosphorus, carbon- and nitrogen interactions in productive and degraded tropical pastures

    NASA Astrophysics Data System (ADS)

    Oberson, A.; Hegglin, D. D.; Nesper, M.; Rao, I.; Fonte, S.; Ramirez, B.; Velasquez, J.; Tamburini, F.; Bünemann, E. K.; Frossard, E.

    2011-12-01

    Pastures are the main land use in deforested areas of tropical South America. The highly weathered soils of these regions usually have low total and available phosphorus (P) contents. Low P availability can strongly limit plant and animal productivity and other soil ecosystem functions. Most introduced pastures of Brachiaria spp. are grass-alone (GA) while some are grass-legume (GL) pastures. The majority of the introduced pastures, particularly the grass-alone are at some state of degradation (GD). Pasture degradation induces severe loss of plant biomass production, with drastic ecological and economic implications. Although the importance of P deficiency in pasture degradation has been recognized, the knowledge generated on stoichiometry of carbon (C), nitrogen (N) and P along pathways of the nutrient cycles of pastures, with different botanical composition and productivity, has been very limited. We will present results of a case study realized during 2010 to 2011 in the forest margins agro-ecosystem of the department of Caquetá, Colombia. Our objectives were to determine: i) whether P availability is lower in degraded compared to productive pastures, and ii) whether the introduction of legumes in the pasture increases P availability through enhanced biological P cycling through plant growth, plant litter decomposition and the soil microbial biomass; and iii) whether pasture types (GA vs GL) and the state of pasture degradation affect the C:N:P ratios in nutrient pools of the soil-plant system. An on-farm study was conducted on nine farms in the department of Caquetá, Colombia. On every farm three different pasture types were studied: degraded grass alone pastures (GD), productive grass-alone pastures (GA) and productive grass-legume pastures (GL). Basic soil characteristics and indicators on soil P status, microbial P cycling, plant biomass production, plant litter deposition and nutrient concentrations in plant tissue were determined. Analysis of P, C and N in the microbial biomass, particulate organic matter and soil aggregates is in progress. Results showed that plant biomass production, litter deposition, soil organic P and basal soil respiration rate were significantly lower in GD than GA pastures. Moreover, clear trends towards lower total C, N, total P and microbial P per unit soil mass and higher Al saturation were observed in soils of GD compared to GA pastures while available soil P content and P concentration in plant biomass did not differ. No significant differences were found in any of the measured soil parameters between the two productive pasture types, GA and GL, but legume biomass has significantly higher N concentration and tends to have higher P concentration than grasses. 15-N natural abundance data indicated that legume N was largely derived from symbiotic N2 fixation. Biological P cycling was clearly reduced in GD compared to productive GA and GL pastures. This work highlights the importance of biological P cycling for developing sustainable pastoral systems and provides new knowledge on interactions of P with C and N.

  4. A stability indicating HPLC method for determination of mebeverine in the presence of its degradation products and kinetic study of its degradation in oxidative condition.

    PubMed

    Souri, E; Aghdami, A Negahban; Adib, N

    2014-01-01

    An HPLC method for determination of mebeverine hydrochloride (MH) in the presence of its degradation products was developed. The degradation of MH was studied under hydrolysis, oxidative and photolysis stress conditions. Under alkaline, acidic and oxidative conditions, degradation of MH was observed. The separation was performed using a Symmetry C18 column and a mixture of 50 mM KH2PO4, acetonitrile and tetrahydrfuran (THF) (63:35:2; v/v/v) as the mobile phase. No interference peaks from degradation products in acidic, alkaline and oxidative conditions were observed. The linearity, accuracy and precision of the method were studied. The method was linear over the range of 1-100 ?g/ml MH (r(2)>0.999) and the CV values for intra-day and inter-day variations were in the range of 1.0-1.8%. The limit of quantification (LOQ) and the limit of detection (LOD) of the method were 1.0 and 0.2 ?g/ml, respectively. Determination of MH in pharmaceutical dosage forms was performed using the developed method. Furthermore the kinetics of the degradation of MH in the presence of hydrogen peroxide was investigated. The proposed method could be a suitable method for routine quality control studies of mebeverine dosage forms. PMID:25657790

  5. A stability indicating HPLC method for determination of mebeverine in the presence of its degradation products and kinetic study of its degradation in oxidative condition

    PubMed Central

    Souri, E.; Aghdami, A. Negahban; Adib, N.

    2014-01-01

    An HPLC method for determination of mebeverine hydrochloride (MH) in the presence of its degradation products was developed. The degradation of MH was studied under hydrolysis, oxidative and photolysis stress conditions. Under alkaline, acidic and oxidative conditions, degradation of MH was observed. The separation was performed using a Symmetry C18 column and a mixture of 50 mM KH2PO4, acetonitrile and tetrahydrfuran (THF) (63:35:2; v/v/v) as the mobile phase. No interference peaks from degradation products in acidic, alkaline and oxidative conditions were observed. The linearity, accuracy and precision of the method were studied. The method was linear over the range of 1-100 ?g/ml MH (r2>0.999) and the CV values for intra-day and inter-day variations were in the range of 1.0-1.8%. The limit of quantification (LOQ) and the limit of detection (LOD) of the method were 1.0 and 0.2 ?g/ml, respectively. Determination of MH in pharmaceutical dosage forms was performed using the developed method. Furthermore the kinetics of the degradation of MH in the presence of hydrogen peroxide was investigated. The proposed method could be a suitable method for routine quality control studies of mebeverine dosage forms. PMID:25657790

  6. 75 FR 8339 - Difenzoquat; Product Cancellation Order for Certain Pesticide Registrations

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-24

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

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

    SciTech Connect

    Kazunga, C.; Aitken, M.D.

    2000-05-01

    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 P16 and Bacillus cereus strain P21 transformed pyrene primarily to cis-4,5-dihydro-4,5-dihydroxypyrene (PYRdHD), the first intermediate in the known pathway for aerobic bacterial mineralization of pyrene. Sphingomonas yanoikuyae strain R1 transformed pyrene to PYRdHD and pyrene-4,5-dione (PYRQ). Both strain R1 and Pseudomonas saccharophila strain P15 transform PYRdHD to PYRQ nearly stoichiometrically, suggesting that PYRQ is formed by oxidation of PYRdHD to 4,5-dihydroxypyrene and subsequent autoxidation of this metabolite. A pyrene-mineralizing organism, Mycobacterium strain PYR-1, also transforms PYRdHD to PYRQ at high initial concentrations of PYRdHD. However, strain PYR-1 is able to use both PYRdHD and PYRQ as growth substrates. PYRdHD strongly inhibited phenanthrene degradation by strains P15 and R1 but had only a minor effect on strains P16 and P21. At their aqueous saturation concentrations, both PYRdHD and PYRQ severely inhibited benzo[a]pyrene mineralization by strains P15 and R1. Collectively, these findings suggest that products derived from pyrene transformation have the potential to accumulate in PAH-contaminated systems and that such products can significantly influence the removal of other PAH. However, these products may be susceptible to subsequent degradation by organisms able to metabolize pyrene more extensively if such organisms are present in the system.

  8. Production of reference ``ancient'' Cu-based alloys and their accelerated degradation methods

    NASA Astrophysics Data System (ADS)

    Casaletto, M. P.; de Caro, T.; Ingo, G. M.; Riccucci, C.

    2006-06-01

    A large number of bronze artefacts found during archaeological excavations carried out in Italy in different contexts have been studied. Their chemical composition and metallurgical features have been determined by the combined use of different analytical surface and bulk techniques, such as optical microscopy (OM), scanning electron microscopy with energy dispersive X-ray micro-analysis (SEM-EDS), X-raydiffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The study of the corrosion products grown on the archaeological Cu-based artefacts and of their metallurgical features has revealed the quite ubiquitous and nearly constant presence of chlorine as the main corroding agent, and the different structures of the alloys. This information has been used to produce reference Cu-based alloys, whose chemical composition and micro-chemical structure is similar to that of the ancient alloys, and to propose the guidelines for carrying out the accelerated degradation tests to produce corroded samples for testing corrosion inhibiting products. The proposed tests were based on soil, chemical and (chemical+soil)-induced degradation, and the micro-chemical structure of the artificially produced corrosion layers has been compared to those grown on archaeological artefacts during burial. The comparison shows that the (chemical+soil)-induced degradation produces “patinas” that are similar to those grown on archaeological artefacts from a chemical, structural and micro-morphological point of view.

  9. Health Aspects of Organophosphorous Pesticides in Asian Countries

    PubMed Central

    Balali-Mood, M; Balali-Mood, K; Moodi, M; Balali-Mood, B

    2012-01-01

    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

  10. 78 FR 75343 - Pesticide Products; Registration Applications for New Active Ingredients

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-11

    ...represented by Technology Sciences Group, Inc., 712 Fifth St., Suite A, Davis CA 95616). Active ingredient: Beauveria bassiana strain ANT-03. Product type: Microbial insecticide. Proposed uses: Foliar-applied insecticide to...

  11. 78 FR 55695 - Notice of Receipt of Pesticide Products; Registration Applications To Register New Uses

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-11

    ...Indianapolis, IN 46268-1054. Active ingredient: 1,3- Dichloropropene. Product Type: Fumigant (Fungicide). Proposed Use: Pineapple. 8. EPA Registration File Symbol/Registration Number: 86203-EA and 86203-1. Docket ID Number:...

  12. 78 FR 78356 - Notice of Receipt of Pesticide Products; Registration Applications To Register New Uses

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-26

    ...Second St., Suite B-107, Davis, CA 95618. Active ingredient: Pseudomonas fluorescens strain CL145A cells and spent fermentation media. Product type: Molluscicide. Proposed uses: Application to listed water bodies and sites for recreational and...

  13. 77 FR 75153 - Notice of Receipt of Pesticide Products; Registration Applications To Register New Uses

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-19

    ...outdoors preplant treatment on bare soil) on crop groups 8, 9, 10...Proposed Use: Non-food preplant soil treatment. Contact: Dominic...Active Ingredient: Propionic Acid. Product Type: Fungicide. Proposed Use: Non-food preplant soil treatment. Contact:...

  14. Lignin degradation, ligninolytic enzymes activities and exopolysaccharide production by Grifola frondosa strains cultivated on oak sawdust

    PubMed Central

    Fernandes, Nona A.; Isikhuemhen, Omoanghe S.; Ohimain, Elijah I.

    2011-01-01

    Fourteen strains of Grifola frondosa (Dicks.) S. F. Gray, originating from different regions (Asia, Europe and North America) were tested for lignin degradation, ligninolytic enzyme activities, protein accumulation and exopolysaccharide production during 55 days of cultivation on oak sawdust. Lignin degradation varied from 2.6 to7.1 % of dry weight of the oak sawdust substrate among tested strains. The loss of dry matter in all screened fungi varied between 11.7 and 33.0%, and the amount of crude protein in the dry substrate varied between 0.94 to 2.55%. The strain, MBFBL 596, had the highest laccase activity (703.3 U/l), and the maximum peroxidase activity of 22.6 U/l was shown by the strain MBFBL 684. Several tested strains (MBFBL 21, 638 and 662) appeared to be good producers of exopolysaccharides (3.5, 3.5 and 3.2 mg/ml respectively). PMID:24031728

  15. Mechanisms of product formation from the pyrolytic thermal degradation of catechol.

    PubMed

    Lomnicki, Slawomir; Truong, Hieu; Dellinger, Barry

    2008-09-01

    Catechol has been identified as one of the most abundant organic products in tobacco smoke and a major molecular precursor for semiquinone type radicals in the combustion of biomass material. The high-temperature gas-phase pyrolysis of catechol under hydrogen-rich and hydrogen-lean conditions was studied using a fused-silica tubular flow reactor coupled to an in-line GC/MS analytical system. Thermal degradation of catechol over temperature range of 250-1000 degrees C with a reaction time of 2.0s yielded a variety products including phenol, benzene, dibenzofuran, dibenzo-p-dioxin, phenylethyne, styrene, indene, anthracene, naphthalene, and biphenylene. Ortho-benzoquinone which is typically associated with the presence of semiquinone radicals was not observed and is proposed to be the result of fast decomposition reactions that lead to a variety of other reaction products. This is in contrast to the decomposition of hydroquinone that produced para-benzoquinone as the major product. A detailed mechanism of the degradation pathway of catechol is proposed. PMID:18640699

  16. Identification and Characterization of Hydrolytic Degradation Products of Cefditoren Pivoxil using LC and LC-MS/TOF.

    PubMed

    Gawande, V T; Bothara, K G; Singh, A; Mahajan, A A

    2015-01-01

    The present research work was carried out to determine stability of cefditoren pivoxil, an orally absorbed prodrug that is rapidly hydrolysed by intestinal esterases to the active cephalosporin cefditoren. Cefditoren was subjected to stress conditions recommended by the International Conference on Harmonization of Technical Requirements for Registration of Pharmaceuticals for Human Use guideline Q1A (R2). Cefditoren pivoxil was susceptible for degradation under acidic, alkaline and neutral hydrolytic conditions while it was stable under photolytic and thermal stress conditions. Separation of cefditoren and degradation products were carried out by using HPLC. The unknown degradation products were characterized by liquid chromatography-mass spectrometry/time of flight studies. Structures were proposed for each fragment based on best possible molecular formula and complete degradation pathways were reported for cefditoren and its degradants. PMID:25767321

  17. Identification and Characterization of Hydrolytic Degradation Products of Cefditoren Pivoxil using LC and LC-MS/TOF

    PubMed Central

    Gawande, V. T.; Bothara, K. G.; Singh, A.; Mahajan, A. A.

    2015-01-01

    The present research work was carried out to determine stability of cefditoren pivoxil, an orally absorbed prodrug that is rapidly hydrolysed by intestinal esterases to the active cephalosporin cefditoren. Cefditoren was subjected to stress conditions recommended by the International Conference on Harmonization of Technical Requirements for Registration of Pharmaceuticals for Human Use guideline Q1A (R2). Cefditoren pivoxil was susceptible for degradation under acidic, alkaline and neutral hydrolytic conditions while it was stable under photolytic and thermal stress conditions. Separation of cefditoren and degradation products were carried out by using HPLC. The unknown degradation products were characterized by liquid chromatography-mass spectrometry/time of flight studies. Structures were proposed for each fragment based on best possible molecular formula and complete degradation pathways were reported for cefditoren and its degradants. PMID:25767321

  18. Poly(dimethylsiloxane) Microchip Electrophoresis with Contactless Conductivity Detection for Measurement of Chemical Warfare Agent Degradation Products

    Microsoft Academic Search

    Yongsheng Ding; Carlos D. Garcia; Kim R. Rogers

    2008-01-01

    The applicability of a poly(dimethylsiloxane) (PDMS) microfluidic device with contactless conductivity detection for the determination of organophosphonate nerve agent degradation products is reported. Five alkyl methylphosphonic acids, isopropyl methylphosphonic acid (IMPA), pinacolyl methylphosphonic acid (PMPA), O?ethyl?N,N?dimethyl phosphoramidate (EDPA), ethyl methylphosphonic acid (EMPA), and methylphosphonic acid (MPA), (degradation products of Sarin, Soman, Tuban and VX nerve agents) were analyzed by microchip

  19. Treatment of a mixture of three pesticides by photo- and electro-Fenton processes

    Microsoft Academic Search

    Aida Kesraoui Abdessalem; Nizar Bellakhal; Nihal Oturan; Mohamed Dachraoui; Mehmet A. Oturan

    2010-01-01

    In the present work, a comparative study of a mixture of three pesticides (chlortoluron, carbofuran and bentazon) has been investigated by advanced oxidation processes such as photo-Fenton and electro-Fenton. These processes are based on the in situ production of hydroxyl radical, a highly strong oxidant, which allows the degradation of organic pollutants until their mineralization into CO2 and H2O. For

  20. Stress Degradation Behavior of Atorvastatin Calcium and Development of a Suitable Stability-Indicating LC Method for the Determination of Atorvastatin, its Related Impurities, and its Degradation Products

    PubMed Central

    Vukkum, Pallavi; Moses Babu, J.; Muralikrishna, R.

    2013-01-01

    A rapid, reversed-phase liquid chromatographic method was developed for the quantitative determination of Atorvastatin calcium, its related substances (12 impurities), and degradation impurities in bulk drugs. The chromatographic separation was achieved on a Zorbax Bonus-RP column by employing a gradient elution with water–acetonitrile–trifluoroacetic acid as the mobile phase in a shorter run time of 25 min. The flow rate was 1.0 mL/min and the detection wavelength was 245 nm. The drug substance was subjected to stress studies such as hydrolysis, oxidation, photolysis, and thermal degradation, and considerable degradation was observed in acidic hydrolysis, oxidative, thermal, and photolytic stress conditions. The formed degradation products were reported and were well-resolved from the Atorvastatin and its related substances. The stressed samples were quantified against a qualified reference standard and the mass balance was found to be close to 99.5% (w/w) when the response of the degradant was considered to be equal to the analyte (i.e. Atorvastatin), which demonstrates the stability-indicating capability of the method. The method was validated in agreement with ICH requirements. The method developed here was single and shorter (25 min method for the determination of all 12 related impurities of Atorvastatin and its degradation products), with clearly better resolution and higher sensitivity than the European (85 min method for the determination of six impurities) and United States pharmacopeia (115 min and 55 min, two different methods for the determination of six related substances). PMID:23641331

  1. Identification of degradation products of ionic liquids in an ultrasound assisted zero-valent iron activated carbon micro-electrolysis system and their degradation mechanism.

    PubMed

    Zhou, Haimei; Lv, Ping; Shen, Yuanyuan; Wang, Jianji; Fan, Jing

    2013-06-15

    Ionic liquids (ILs) have potential applications in many areas of chemical industry because of their unique properties. However, it has been shown that the ILs commonly used to date are toxic and not biodegradable in nature, thus development of efficient chemical methods for the degradation of ILs is imperative. In this work, degradation of imidazolium, piperidinium, pyrrolidinium and morpholinium based ILs in an ultrasound and zero-valent iron activated carbon (ZVI/AC) micro-electrolysis system was investigated, and some intermediates generated during the degradation were identified. It was found that more than 90% of 1-alkyl-3-methylimidazolium bromide ([Cnmim]Br, n = 2, 4, 6, 8, 10) could be degraded within 110 min, and three intermediates 1-alkyl-3-methyl-2,4,5-trioxoimidazolidine, 1-alkyl-3-methylurea and N-alkylformamide were detected. On the other hand, 1-butyl-1-methylpiperidinium bromide ([C4mpip]Br), 1-butyl-1-methylpyrrolidinium bromide ([C4mpyr]Br) and N-butyl-N-methylmorpholinium bromide ([C4mmor]Br) were also effectively degraded through the sequential oxidization into hydroxyl, carbonyl and carboxyl groups in different positions of the butyl side chain, and then the N-butyl side chain was broken to form the final products of N-methylpiperidinium, N-methylpyrrolidinium and N-methylmorpholinium, respectively. Based on these intermediate products, degradation pathways of these ILs were suggested. These findings may provide fundamental information on the assessment of the factors related to the environmental fate and environmental behavior of these commonly used ILs. PMID:23623468

  2. Stress Degradation Behavior of Abacavir Sulfate and Development of a Suitable Stability-Indicating UHPLC Method for the Determination of Abacavir, its Related Substances, and Degradation Products

    PubMed Central

    Vukkum, Pallavi; Deshpande, Girish R.; Babu, J. Moses; Muralikrishna, R.; Jagu, Pavani

    2012-01-01

    A novel, stability-indicating UHPLC method was developed for the quantitative determination of Abacavir sulfate, its related substances, and forced degradation impurities in bulk drugs. The chromatographic separation was achieved on a Waters Acquity BEH C8, 50 mm × 2.1 mm, 1.7 ?m particle size column with a mobile containing a gradient mixture of solution A (0.10 % v/v o-phosphoric acid in water) and solution B (0.10% v/v o-phosphoric acid in methanol). The flow rate was set at 0.40 mL/min and the run time was 6.0 min. The drug substance was subjected to the stress studies of hydrolysis, oxidation, photolysis, and thermal degradation. Abacavir sulfate was found to degrade significantly under acidic hydrolysis and oxidative stress conditions. The formed degradation products were reported and were well-resolved from Abacavir and its related substances. The mass balance was found to be satisfactory in all of the stress conditions, thus proving the stability-indicating capability of the method. The developed UHPLC method was validated to be in agreement with ICH requirements and found to be rapid, accurate, precise, linear, specific, and suitable for the quantitative determination of related substances and degradants in the bulk drug samples of Abacavir sulfate. PMID:23264939

  3. NATURAL PRODUCTS AS PESTICIDAL AGENTS FOR CONTROL OF THE FORMOSAN TERMITE (COPTOTERMES FORMOSANUS)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An overview of the literature on investigations of natural products for use against the termite pest Coptotermes formosanus. Our current results in this field are also presented. Results obtained from components of natural sources known to be associated with antitermite activity are presented. Re...

  4. Reducing the Environmental Risk of Pesticides: Implications of Management Practices in Agricultural Production

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A common management practice for the production of fresh-market vegetables uses polyethylene (plastic) mulch to increase soil temperature, maintain soil moisture and reduce weed pressure. However, multiple applications of fungicides and insecticides are required, and rain events afford more runoff ...

  5. A Review on the Fate of Pesticides during the Processes within the Food-Production Chain

    Microsoft Academic Search

    R. M. González-Rodríguez; R. Rial-Otero; B. Cancho-Grande; C. Gonzalez-Barreiro; J. Simal-Gándara

    2011-01-01

    Only the intake of toxicologically-significant amounts can lead to adverse health effects even for a relatively toxic substance. In the case of residues in foods this is based on two major aspects—first, how to determine quantitatively the presence of a pollutant in individual foods and diets, including its fate during the processes within the food production chain; and second, how

  6. 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 ...

  7. 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...

  8. Sonochemical degradation of perchloroethylene: the influence of ultrasonic variables, and the identification of products.

    PubMed

    Sáez, V; Esclapez, M D; Bonete, P; Walton, D J; Rehorek, A; Louisnard, O; González-García, J

    2011-01-01

    Sonochemistry is a technique that offers promise for pollutant degradation, but earlier studies on various chlorinated substrates do not give a definitive view of the effectiveness of this methodology. We now report a thorough study of ultrasonic operational variables upon perchloroethylene (PCE) degradation in water (variables include ultrasonic frequency, power and system geometry as well as substrate concentration) and we attempt to close the mass balance where feasible. We obtained fractional conversions of >97% showing very effective loss of pollutant starting material, and give mechanistic proposals for the reaction pathway based on cavitational phenomena inducing pyrolytic and free radical processes. We note major products of Cl(-) and CO(2)/CO, and also trichloroethylene (TCE) and dichloroethylene (DCE) at ppm concentrations as reported earlier. The formation at very low (ppb) concentration of small halocompounds (CHCl(3), CCl(4)) and also of higher-mass species, such as pentachloropropene, hexachloroethane, is noteworthy. But of particular importance in our work is the discovery of significant quantities of chloroacetate derivatives at ppm concentrations. Although these compounds have been described as by-products with other techniques such as radiolysis or photochemistry, this is the first time that these products have been identified in the sonochemical treatment of PCE; this allows a much more effective account of the mass balance and may explain earlier inconsistencies. This reaction system is now better identified, but a corollary is that, because these haloacetates are themselves species of some toxicity, the use of ultrasound here may not sufficiently diminish wastewater toxicity. PMID:20403718

  9. EDS and ?-XRF mapping of amalgam degradation products in ancient mirrors.

    PubMed

    Arizio, E; Orsega, E F; Falcone, R; Vallotto, M

    2014-12-01

    An amalgam mirror is a mirror type, used from the fifteenth century until the end of the nineteenth century, where the reflective layer is constituted by a tin amalgam layer adhered to a glass sheet. In this work, two amalgam mirrors samples were studied by scanning electron microscopy with an energy dispersive spectrometer and by micro-X-ray fluorescence elemental mapping to go deeply into the understanding of the degradation mechanism of the amalgam layer of ancient mirrors. The investigation has been focused for the first time on the reflective surface of the amalgam layer adherent to the glass sheet to better understand the processes of amalgam corrosion. The two amalgam degradation compounds, romarchite and cassiterite, has been spatially differentiated by scanning electron microscope (SEM) and energy dispersive spectrometer (EDS) maps. SEM images and micro-X-ray fluorescence and EDS maps showed that the amalgam degradation products grow up to form hemispherical stratified calottes. This structure is probably due to a mechanism involves cyclic phases and oxygen radial diffusion from a superficial oxidation nucleus. PMID:24420559

  10. Production, structure and in vitro degradation of electrospun honeybee silk nanofibers

    PubMed Central

    Wittmer, Corinne R.; Hu, Xiao; Gauthier, Pierre-Chanel; Weisman, Sarah; Kaplan, David L.; Sutherland, Tara D.

    2012-01-01

    Honeybees produce silken cocoons containing four related fibrous proteins. High levels of each of the honeybee silk proteins can be produced recombinantly by fermentation in E. coli. In this study we have used electrospinning to fabricate a single recombinant honeybee silk protein, AmelF3, into nanofibres of around 200 nm diameter. Infrared spectroscopy found that the molecular structure of the nanofibres was predominantly coiled coil, essentially the same as native honeybee silk. Mats of the honeybee nanofibres were treated with methanol or by water annealing, which increased their ß-sheet content and rendered them water-insensitive. The insoluble mats were degraded by protease on a time scale of hours to days. The protease gradually released proteins from the solid state and these were subsequently rapidly degraded into small peptides without the accumulation of partial degradation products. Cell culture assays demonstrated that the mats allowed survival, attachment and proliferation of fibroblasts. These results indicate that honeybee silk proteins meet many prerequisites for use as a biomaterial. PMID:21689795

  11. Photolysis of nonylphenol ethoxylates: the determination of the degradation kinetics and the intermediate products.

    PubMed

    Chen, Ling; Zhou, Hai-Yun; Deng, Qin-Ying

    2007-06-01

    The photolysis of nonylphenol ethoxylates with an average oligomers length of ten ethoxylate units (NPEO(10)) in aqueous solution under UV, as well as the influence of humic acid (HA) on the photolysis was studied. A 125W high-pressure mercury lamp was employed as the light source. The intermediate products from the photolysis were determined by LC-MS. The results indicated that NPEO(10) underwent direct photolysis upon exposed to UV. The degradation pathway was complex. Besides the generally proposed degradation pathway of ethylene oxide (EO) side chains shortening, the oxidation of alkyl chain and EO chain led to intermediates having both a carboxylated (as well as carbonylated) ethoxylate and alkyl chain of varying lengths. The hydrogenation of benzene ring was also detected. The kinetics data showed that the first order reaction kinetics could be well used to describe the kinetics of NPEO(10) degradation. In the presence of dissolved organic matter by HA addition, the performance of NPEO(10) photodegradation was reduced. The photolysis rate decreased with increased HA concentration. PMID:17280701

  12. Antibiotic, pesticide, and microbial contaminants of honey: human health hazards.

    PubMed

    Al-Waili, Noori; Salom, Khelod; Al-Ghamdi, Ahmed; Ansari, Mohammad Javed

    2012-01-01

    Agricultural contamination with pesticides and antibiotics is a challenging problem that needs to be fully addressed. Bee products, such as honey, are widely consumed as food and medicine and their contamination may carry serious health hazards. Honey and other bee products are polluted by pesticides, heavy metals, bacteria and radioactive materials. Pesticide residues cause genetic mutations and cellular degradation and presence of antibiotics might increase resistant human or animal's pathogens. Many cases of infant botulisms have been attributed to contaminated honey. Honey may be very toxic when produced from certain plants. Ingestion of honey without knowing its source and safety might be problematic. Honey should be labeled to explore its origin, composition, and clear statement that it is free from contaminants. Honey that is not subjected for analysis and sterilization should not be used in infants, and should not be applied to wounds or used for medicinal purposes. This article reviews the extent and health impact of honey contamination and stresses on the introduction of a strict monitoring system and validation of acceptable minimal concentrations of pollutants or identifying maximum residue limits for bee products, in particular, honey. PMID:23097637

  13. 1D-NMR and 2D-NMR analysis of the thermal degradation products from vitrinites in relation to their

    E-print Network

    Boyer, Edmond

    is the most commonly used degradation method in the study of macromolecular materials due to the fact1D-NMR and 2D-NMR analysis of the thermal degradation products from vitrinites in relation the volatile and non-volatile fractions of the degradation products. From a study of selected perhydrous coals

  14. Protocol for an electrospray ionization tandem mass spectral product ion library: development and application for identification of 240 pesticides in foods.

    PubMed

    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

    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

  15. Pesticide use in agriculture.

    PubMed Central

    Ridgway, R L; Tinney, J C; MacGregor, J T; Starler, N J

    1978-01-01

    During the last three decades, the use of modern organic synthetic pesticides has increased about 40-fold. Total U.S. production, for domestic and expert use, in 1976 was about 1.4 million pounds. Crops receiving the most intensive application of various pesticides were cotton for insecticides, corn for herbicides, and fruits and vegetables for fungicides. Examination of use trends of pesticides indicates that the volume in pounds of herbicides used on crops is increasing, whereas the quantities of insecticides and fungicides remain stable. New chemical classes of compounds such as the synthetic pyrethroid insecticides are being introduced, but are not yet significant in terms of their share of the market. The increased usage of pesticides, together with knowledge of some of their adverse effects, has alerted the public to the need for regulation. To assist in the regulatory decision-making process, emphasis is being placed on benefit-cost analyses. Additional and improved biological inputs and methodologies are needed to provide accurate analyses. PMID:104870

  16. Genotoxic effects of pesticides.

    PubMed

    Kornuta, N; Bagley, E; Nedopitanskaya, N

    1996-01-01

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

  17. Hydrogeologic framework and sampling design for an assessment of agricultural pesticides in ground water in Pennsylvania

    USGS Publications Warehouse

    Lindsey, Bruce D.; Bickford, Tammy M.

    1999-01-01

    State agencies responsible for regulating pesticides are required by the U.S. Environmental Protection Agency to develop state management plans for specific pesticides. A key part of these management plans includes assessing the potential for contamination of ground water by pesticides throughout the state. As an example of how a statewide assessment could be implemented, a plan is presented for the Commonwealth of Pennsylvania to illustrate how a hydrogeologic framework can be used as a basis for sampling areas within a state with the highest likelihood of having elevated pesticide concentrations in ground water. The framework was created by subdividing the state into 20 areas on the basis of physiography and aquifer type. Each of these 20 hydrogeologic settings is relatively homogeneous with respect to aquifer susceptibility and pesticide use?factors that would be likely to affect pesticide concentrations in ground water. Existing data on atrazine occurrence in ground water was analyzed to determine (1) which areas of the state already have suffi- cient samples collected to make statistical comparisons among hydrogeologic settings, and (2) the effect of factors such as land use and aquifer characteristics on pesticide occurrence. The theoretical vulnerability and the results of the data analysis were used to rank each of the 20 hydrogeologic settings on the basis of vulnerability of ground water to contamination by pesticides. Example sampling plans are presented for nine of the hydrogeologic settings that lack sufficient data to assess vulnerability to contamination. Of the highest priority areas of the state, two out of four have been adequately sampled, one of the three areas of moderate to high priority has been adequately sampled, four of the nine areas of moderate to low priority have been adequately sampled, and none of the three low priority areas have been sampled. Sampling to date has shown that, even in the most vulnerable hydrogeologic settings, pesticide concentrations in ground water rarely exceed U.S. Environmental Protection Agency Drinking Water Standards or Health Advisory Levels. Analyses of samples from 1,159 private water supplies reveal only 3 sites for which samples with concentrations of pesticides exceeded drinking-water standards. In most cases, samples with elevated concentrations could be traced to point sources at pesticide loading or mixing areas. These analyses included data from some of the most vulnerable areas of the state, indicating that it is highly unlikely that pesticide concentrations in water from wells in other areas of the state would exceed the drinking-water standards unless a point source of contamination were present. Analysis of existing data showed that water from wells in areas of the state underlain by carbonate (limestone and dolomite) bedrock, which commonly have a high percentage of corn production, was much more likely to have pesticides detected. Application of pesticides to the land surface generally has not caused concentrations of the five state priority pesticides in ground water to exceed health standards; however, this study has not evaluated the potential human health effects of mixtures of pesticides or pesticide degradation products in drinking water. This study also has not determined whether concentrations in ground water are stable, increasing, or decreasing.

  18. PAN Pesticide Database

    NSDL National Science Digital Library

    0000-00-00

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

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

    SciTech Connect

    Polidoro, Beth A. [Department of Plant, Soil and Entomological Sciences, University of Idaho, P.O. Box 442339, Moscow, ID 83844-2339 (United States); Department of Agroforestry, Tropical Agricultural Research and Higher Education Center (CATIE), Turrialba (Costa Rica)], E-mail: bethpolidoro@vandals.uidaho.edu; Dahlquist, Ruth M. [Department of Plant, Soil and Entomological Sciences, University of Idaho, P.O. Box 442339, Moscow, ID 83844-2339 (United States); Department of Agroforestry, Tropical Agricultural Research and Higher Education Center (CATIE), Turrialba (Costa Rica); Castillo, Luisa E. [Central American Institute for Studies on Toxic Substances (IRET), Universidad Nacional, Heredia (Costa Rica); Morra, Matthew J. [Department of Plant, Soil and Entomological Sciences, University of Idaho, P.O. Box 442339, Moscow, ID 83844-2339 (United States); Somarriba, Eduardo [Department of Agroforestry, Tropical Agricultural Research and Higher Education Center (CATIE), Turrialba (Costa Rica); Bosque-Perez, Nilsa A. [Department of Plant, Soil and Entomological Sciences, University of Idaho, P.O. Box 442339, Moscow, ID 83844-2339 (United States)

    2008-09-15

    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 in Costa Rica, especially in remote, high-poverty areas such as the Bribri-Cabecar Indigenous Territories. Our objective was to integrate a rapid rural appraisal of indigenous farmer pesticide application practices and pest knowledge with a cost-benefit analysis of plantain production in the Bribri-Cabecar Indigenous Territories, for the development of better agricultural management practices and improved regulatory infrastructure. Interviews conducted with 75 households in 5 indigenous communities showed that over 60% of participants grew plantain with agrochemicals. Of these plantain farmers, over 97% used the insecticide chlorpyrifos, and 84% applied nematicides, 64% herbicides, and 22% fungicides, with only 31% of participants reporting the use of some type of protective clothing during application. The banana weevil (Cosmopolites sordidus Germar) was ranked as the most important agricultural pest by 85% of participants, yet only 28% could associate the adult and larval form. A cost-benefit analysis conducted with a separate group of 26 plantain farmers identified several national markets and one export market for plantain production in the Indigenous Territories. Yearly income averaged US$6200/ha and yearly expenses averaged US$1872/ha, with an average cost-benefit ratio of 3.67 for plantain farmers. Farmers applied an average of 9.7 kg a.i./ha/yr of pesticide products and 375 kg/ha/yr of fertilizer, but those who sold their fruit to the national markets applied more nematicides, herbicides, and fertilizers than those who sold primarily to export markets, suggesting a lack of appropriate application knowledge. Results indicate that the quantity of agrochemicals applied in plantain cultivation is less than that applied in export banana, but the absence of appropriate agrochemical application practices in plantain cultivation may pose serious risks to human and environmental health. Culturally appropriate farmer education and certification programs are needed as well as the development of safe-handling practices, regulatory infrastructure, and adequate agrochemical storage, transport, and waste disposal facilities. Long-term solutions however, are dependent on the development of policies and infrastructure that support non-chemical pest management, alternatives to pesticides, and the identification of organic plantain markets.

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

    PubMed

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

    2008-09-01

    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 in Costa Rica, especially in remote, high-poverty areas such as the Bribri-Cabécar Indigenous Territories. Our objective was to integrate a rapid rural appraisal of indigenous farmer pesticide application practices and pest knowledge with a cost-benefit analysis of plantain production in the Bribri-Cabécar Indigenous Territories, for the development of better agricultural management practices and improved regulatory infrastructure. Interviews conducted with 75 households in 5 indigenous communities showed that over 60% of participants grew plantain with agrochemicals. Of these plantain farmers, over 97% used the insecticide chlorpyrifos, and 84% applied nematicides, 64% herbicides, and 22% fungicides, with only 31% of participants reporting the use of some type of protective clothing during application. The banana weevil (Cosmopolites sordidus Germar) was ranked as the most important agricultural pest by 85% of participants, yet only 28% could associate the adult and larval form. A cost-benefit analysis conducted with a separate group of 26 plantain farmers identified several national markets and one export market for plantain production in the Indigenous Territories. Yearly income averaged US$6200/ha and yearly expenses averaged US$1872/ha, with an average cost-benefit ratio of 3.67 for plantain farmers. Farmers applied an average of 9.7 kg a.i./ha/yr of pesticide products and 375 kg/ha/yr of fertilizer, but those who sold their fruit to the national markets applied more nematicides, herbicides, and fertilizers than those who sold primarily to export markets, suggesting a lack of appropriate application knowledge. Results indicate that the quantity of agrochemicals applied in plantain cultivation is less than that applied in export banana, but the absence of appropriate agrochemical application practices in plantain cultivation may pose serious risks to human and environmental health. Culturally appropriate farmer education and certification programs are needed as well as the development of safe-handling practices, regulatory infrastructure, and adequate agrochemical storage, transport, and waste disposal facilities. Long-term solutions however, are dependent on the development of policies and infrastructure that support non-chemical pest management, alternatives to pesticides, and the identification of organic plantain markets. PMID:18555986

  1. Accurate quantitation of pentaerythritol tetranitrate and its degradation products using liquid chromatography-atmospheric pressure chemical ionization-mass spectrometry.

    PubMed

    Brust, Hanneke; van Asten, Arian; Koeberg, Mattijs; Dalmolen, Jan; van der Heijden, Antoine; Schoenmakers, Peter

    2014-04-18

    After an explosion of pentaerythritol tetranitrate (PETN), its degradation products pentaerythritol trinitrate (PETriN), dinitrate (PEDiN) and mononitrate (PEMN) were detected using liquid chromatography-atmospheric-pressure chemical-ionization-mass spectrometry (LC-APCI-MS). Discrimination between post-explosion and naturally degraded PETN could be achieved based on the relative amounts of the degradation products. This information can be used as evidence when investigating a possible relationship between a suspect and a post-explosion crime scene. The present work focuses on accurate quantitation of PETN and its degradation products, using PETriN, PEDiN and PEMN standards specifically synthesized for this purpose. With the use of these standards, the ionization behavior of these compounds was studied, and a quantitative method was developed. Quantitation of PETN and trace levels of its degradation products was shown to be possible with accuracy between 85.7% and 103.7% and a precision ranging from 1.3% to 11.5%. The custom-made standards resulted in a more robust and reliable method to discriminate between post-explosion and naturally-degraded PETN. PMID:24656542

  2. Advanced oxidation of a commercially important nonionic surfactant: investigation of degradation products and toxicity.

    PubMed

    Karci, Akin; Arslan-Alaton, Idil; Bekbolet, Miray

    2013-12-15

    The evolution of degradation products and changes in acute toxicity during advanced oxidation of the nonionic surfactant nonylphenol decaethoxylate (NP-10) with the H2O2/UV-C and photo-Fenton processes were investigated. H2O2/UV-C and photo-Fenton processes ensured complete removal of NP-10, which was accompanied by the generation of polyethylene glycols with 3-8 ethoxy units. Formation of aldehydes and low carbon carboxylic acids was evidenced. According to the acute toxicity tests carried out with Vibrio fischeri, degradation products being more inhibitory than the original NP-10 solution were formed after the H2O2/UV-C process, whereas the photo-Fenton process appeared to be toxicologically safer since acute toxicity did not increase relative to the original NP-10 solution after treatment. Temporal evolution of the acute toxicity was strongly correlated with the identified carboxylic acids being formed during the application of H2O2/UV-C and photo-Fenton processes. PMID:23608751

  3. Emulsions stabilized by precipitates of zirconium and tributyl phosphate degradation products

    SciTech Connect

    Sugai, H.; Munakata, K. (Sumitomo Metal Mining Co., Ltd., Tokai Research Center 2600, Ishigamitojuku, Tokai-mura, Ibaraki-ken 319-11 (JP)); Miyachi, S.; Yasu, S. (Power Reactor and Nuclear Fuel Development Corp., Tokai Works Reprocessing Plant, Analysis Section, Tokai-mura, Ibaraki-ken 319-11 (JP))

    1992-05-01

    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 formed by precipitates of zirconium and TBP degradation products, such as di-n-butyl phosphate (HDBP), mono-n-butyl phosphate (H{sub 2}MBP), and phosphoric acid (H{sub 3}PO{sub 4}) are studied. Experimental results show that the precipitate of zirconium and HDBP is not effective in stabilizing emulsions. However, the refractory complex of zirconium and H{sub 3}PO{sub 4} is an important material for stabilizing an oil-in-water emulsion in a solution with or without uranium. Moreover, it is shown that the complex of zirconium and H{sub 2}MBP has a significant role in stabilizing a water-in-oil emulsion, especially when uranium is also present.

  4. Degradation of Three Aromatic Dyes by White Rot Fungi and the Production of Ligninolytic Enzymes

    PubMed Central

    Jayasinghe, Chandana; Imtiaj, Ahmed; Lee, Geon Woo; Im, Kyung Hoan; Hur, Hyun; Lee, Min Woong; Yang, Hee-Sun

    2008-01-01

    This study was conducted to evaluate the degradation of aromatic dyes and the production of ligninolytic enzymes by 10 white rot fungi. The results of this study revealed that Pycnoporus cinnabarinus, Pleurotus pulmonarius, Ganoderma lucidum, Trametes suaveolens, Stereum ostrea and Fomes fomentarius have the ability to efficiently degrade congo red on solid media. However, malachite green inhibited the mycelial growth of these organisms. Therefore, they did not effectively decolorize malachite green on solid media. However, P. cinnabarinus and P. pulmonarius were able to effectively decolorize malachite green on solid media. T. suaveolens and F. rosea decolorized methylene blue more effectively than any of the other fungi evaluated in this study. In liquid culture, G. lucidum, P. cinnabarinus, Naematoloma fasciculare and Pycnoporus coccineus were found to have a greater ability to decolorize congo red. In addition, P. cinnabarinus, G. lucidum and T. suaveolens decolorized methylene blue in liquid media more effectively than any of the other organisms evaluated in this study. Only F. fomentarius was able to decolorize malachite green in liquid media, and its ability to do so was limited. To investigate the production of ligninolytic enzymes in media containing aromatic compounds, fungi were cultured in naphthalene supplemented liquid media. P. coccineus, Coriolus versicolor and P. cinnabarinus were found to produce a large amount of laccase when grown in medium that contained napthalene. PMID:23990745

  5. Degradation of three aromatic dyes by white rot fungi and the production of ligninolytic enzymes.

    PubMed

    Jayasinghe, Chandana; Imtiaj, Ahmed; Lee, Geon Woo; Im, Kyung Hoan; Hur, Hyun; Lee, Min Woong; Yang, Hee-Sun; Lee, Tae-Soo

    2008-06-01

    This study was conducted to evaluate the degradation of aromatic dyes and the production of ligninolytic enzymes by 10 white rot fungi. The results of this study revealed that Pycnoporus cinnabarinus, Pleurotus pulmonarius, Ganoderma lucidum, Trametes suaveolens, Stereum ostrea and Fomes fomentarius have the ability to efficiently degrade congo red on solid media. However, malachite green inhibited the mycelial growth of these organisms. Therefore, they did not effectively decolorize malachite green on solid media. However, P. cinnabarinus and P. pulmonarius were able to effectively decolorize malachite green on solid media. T. suaveolens and F. rosea decolorized methylene blue more effectively than any of the other fungi evaluated in this study. In liquid culture, G. lucidum, P. cinnabarinus, Naematoloma fasciculare and Pycnoporus coccineus were found to have a greater ability to decolorize congo red. In addition, P. cinnabarinus, G. lucidum and T. suaveolens decolorized methylene blue in liquid media more effectively than any of the other organisms evaluated in this study. Only F. fomentarius was able to decolorize malachite green in liquid media, and its ability to do so was limited. To investigate the production of ligninolytic enzymes in media containing aromatic compounds, fungi were cultured in naphthalene supplemented liquid media. P. coccineus, Coriolus versicolor and P. cinnabarinus were found to produce a large amount of laccase when grown in medium that contained napthalene. PMID:23990745

  6. Production and Properties of Xylan-Degrading Enzymes from Cellulomonas uda

    PubMed Central

    Rapp, Peter; Wagner, Fritz

    1986-01-01

    Xylan degradation and production of ?-xylanase and ?-xylosidase activities were studied in cultures of Cellulomonas uda grown on purified xylan from birchwood. ?-Xylanase activity was found to be associated with the cells, although in various degrees. The formation of ?-xylanase activity was induced by xylotriose and repressed by xylose. ?-Xylosidase activity was cell bound. Both constitutive and inducible ?-xylosidase activities were suggested. ?-Xylanase and ?-xylosidase activities were inhibited competitively by xylose. ?-Xylanase activity had a pronounced optimum pH of 5.8, whereas the optimum pH of ?-xylosidase activity ranged from 5.4 to 6.1. The major products of xylan degradation by a crude preparation of ?-xylanase activity, in decreasing order of amount, were xylobiose, xylotriose, xylose, and small amounts of xylotetraose. This pattern suggests that ?-xylanase activity secreted by C. uda is of the endosplitting type. Supernatants of cultures grown on cellulose showed not only ?-glucanase but also ?-xylanase activity. The latter could be attributed to an endo-1,4-?-glucanase activity which had a low ?-xylanase activity. PMID:16347038

  7. Production of keratinolytic enzyme by an indigenous feather-degrading strain Bacillus cereus Wu2.

    PubMed

    Lo, Wei-Hsun; Too, Jui-Rze; Wu, Jane-Yii

    2012-12-01

    A novel feather-degrading microorganism was isolated from a poultry farm in Taiwan, and was identified Bacillus cereus Wu2 according to 16S rRNA sequencing. The isolated strain produces keratinolytic enzyme using chicken feather as the sole carbon and nitrogen source. The experimental results indicated that the extra carbon sources (glucose, fructose, starch, sucrose, or lactose) could act as a catabolite repressor to the enzyme secretion or keratinolytic activity when keratinous substrates were employed as protein sources. However, addition of 2 g/L of NH(4)Cl to the feather medium increased the enzyme production. The optimum temperature and initial pH for enzyme production were 30°C and 7.0, respectively. The maximum yield of the enzyme was 1.75 kU/mL in the optimal chicken feather medium; this value was about 17-fold higher than the yield in the basal hair medium. The B. cereus Wu2 possessed disulfide reductase activity along with keratinolytic activity. The amino acid contents of feathers degradated by B. cereus Wu2 were higher, especially for lysine, methionine and threonine which were nutritionally essential amino acids and usually deficient in the feather meal. Thus, B. cereus Wu2 could be not only used to enhance the nutritional value of feather meal but is also a potential bioinoculant in agricultural environments. PMID:22999356

  8. Continuous flow stable isotope methods for study of ?13C fractionation during halomethane production and degradation

    USGS Publications Warehouse

    Kalin, Robert M.; Hamilton, John T.G.; Harper, David B.; Miller, Laurence G.; Lamb, Clare; Kennedy, James T.; Downey, Angela; McCauley, Sean; Goldstein, Allen H.

    2001-01-01

    Gas chromatography/mass spectrometry/isotope ratio mass spectrometry (GC/MS/IRMS) methods for ?13C measurement of the halomethanes CH3Cl, CH3Br, CH3I and methanethiol (CH3SH) during studies of their biological production, biological degradation, and abiotic reactions are presented. Optimisation of gas chromatographic parameters allowed the identification and quantification of CO2, O2, CH3Cl, CH3Br, CH3I and CH3SH from a single sample, and also the concurrent measurement of ?13C for each of the halomethanes and methanethiol. Precision of ?13C measurements for halomethane standards decreased (±0.3, ±0.5 and ±1.3‰) with increasing mass (CH3Cl, CH3Br, CH3I, respectively). Given that carbon isotope effects during biological production, biological degradation and some chemical (abiotic) reactions can be as much as 100‰, stable isotope analysis offers a precise method to study the global sources and sinks of these halogenated compounds that are of considerable importance to our understanding of stratospheric ozone destruction. 

  9. Glucosinolate degradation products, isothiocyanates, nitriles, and thiocyanates, induce stomatal closure accompanied by peroxidase-mediated reactive oxygen species production in Arabidopsis thaliana.

    PubMed

    Hossain, Mohammad Shakhawat; Ye, Wenxiu; Hossain, Mohammad Anowar; Okuma, Eiji; Uraji, Misugi; Nakamura, Yoshimasa; Mori, Izumi C; Murata, Yoshiyuki

    2013-01-01

    Isothiocyanates, nitriles, and thiocyanates are degradation products of glucosinolates in crucifer plants. In this study, we investigated the stomatal response to allyl isothiocyanate (AITC), 3-butenenitrile (3BN), and ethyl thiocyanate (ESCN) in Arabidopsis. AITC, 3BN, and ESCN induced stomatal closure in the wild type and the atrbohD atrbohF mutant. Stomatal closure was inhibited by catalase and salicylhydroxamic acid (SHAM). The degradation products induced extracellular reactive oxygen species (ROS) production in the rosette leaves, and intracellular ROS accumulation, NO production, and cytosolic free calcium concentration ([Ca(2+)]cyt) oscillations in guard cells, which were inhibited by SHAM. These results suggest that glucosinolate degradation products induce stomatal closure accompanied by extracellular ROS production mediated by SHAM-sensitive peroxidases, intracellular ROS accumulation, and [Ca(2+)]cyt oscillation in Arabidopsis. PMID:23649257

  10. Potential Enhancement of Biofuel Production Through Enzymatic Biomass Degradation Activity and Biodiesel Production by Halophilic Microorganisms

    Microsoft Academic Search

    Matthew B. Begemann; Melanie R. Mormile; Varun G. Paul; Daniel J. Vidt

    \\u000a There are many economic and negative environmental impacts that need to be solved before biofuels become a viable replacement\\u000a for some of the fossil fuel demand. One environmental problem is the great amount of water required for the production of\\u000a biofuels. The use of halophilic\\/halotolerant algae can greatly reduce the amount of water required for biodiesel production.\\u000a The use of

  11. NATURAL PESTICIDES AND TWO SYNTHETIC INSECTICIDES THAT WERE USED IN BIOASSAYS No. Product Trade Name Active Ingredients Manufacturer/Distributor

    E-print Network

    Wang, Changlu

    -based pesticides, referred to in this article as biopesticides, flourished in the consumer market. Many natural a field strain of bed bugs. Researchers at Rutgers University tested nine commonly available biopesticides, a biopesticide marketed to consumers, recently was studied by Rutgers researchers. 28 /// MARCH 2013 WWW

  12. Organochlorine pesticides, polychlorinated biphenyls, and mercury in osprey eggs — 1970–79 — and their relationships to shell thinning and productivity

    Microsoft Academic Search

    Stanley N. Wiemeyer; Christine M. Bunck; Alexander J. Krynitsky

    1988-01-01

    Osprey (Pandion haliaetus) eggs were collected in 14 states in 1970–79 and analyzed for organochlorine pesticides, polychlorinated biphenyls (PCBs), and mercury. Moderate shell thinning occurred in eggs from several areas. DDE was detected in all eggs, PCBs in 99%, DDD in 96%, dieldrin in 52%, and other compounds less frequently. Concentrations of DDT and its metabolites declined in eggs from

  13. Pesticides and Pregnancy

    MedlinePLUS

    Pesticides and Pregnancy In every pregnancy, a woman starts out with a 3-5% chance of having ... advice from your health care provider. What are pesticides? A pesticide is a substance used to prevent ...

  14. Effects of 1,3-Butadiene, Isoprene, and Their Photochemical Degradation Products on Human Lung Cells

    PubMed Central

    Doyle, Melanie; Sexton, Kenneth G.; Jeffries, Harvey; Bridge, Kevin; Jaspers, Ilona

    2004-01-01

    Because of potential exposure both in the workplace and from ambient air, the known carcinogen 1,3-butadiene (BD) is considered a priority hazardous air pollutant. BD and its 2-methyl analog, isoprene (ISO), are chemically similar but have very different toxicities, with ISO showing no significant carcinogenesis. Once released into the atmosphere, reactions with species induced by sunlight and nitrogen oxides convert BD and ISO into several photochemical reaction products. In this study, we determined the relative toxicity and inflammatory gene expression induced by exposure of A549 cells to BD, ISO, and their photochemical degradation products in the presence of nitric oxide. Gas chromatography and mass spectrometry analyses indicate the initial and major photochemical products produced during these experiments for BD are acrolein, acetaldehyde, and formaldehyde, and products for ISO are methacrolein, methyl vinyl ketone, and formaldehyde; both formed < 200 ppb of ozone. After exposure the cells were examined for cytotoxicity and interleukin-8 (IL-8) gene expression, as a marker for inflammation. These results indicate that although BD and ISO alone caused similar cytotoxicity and IL-8 responses compared with the air control, their photochemical products significantly enhanced cytotoxicity and IL-8 gene expression. This suggests that once ISO and BD are released into the environment, reactions occurring in the atmosphere transform these hydrocarbons into products that induce potentially greater adverse health effects than the emitted hydrocarbons by themselves. In addition, the data suggest that based on the carbon concentration or per carbon basis, biogenic ISO transforms into products with proinflammatory potential similar to that of BD products. PMID:15531432

  15. Study of the degradation products of bromopropylate, chlordimeform, coumaphos, cymiazole, flumethrin and tau-fluvalinate in aqueous media

    Microsoft Academic Search

    E. Corta; A. Bakkali; A. Barranco; L. A. Berrueta; B. Gallo; F. Vicente; S. Bogdanov

    2000-01-01

    Degradation processes of bromopropylate, coumaphos, chlordimeform, cymiazole, flumethrin and fluvalinate in aqueous media have been studied by HPLC. Cymiazole is stable at any tested pH (1–11), while bromopropylate, flumethrin and coumaphos are unstable at basic pH and chlordimeform and fluvalinate in neutral and basic media. The main degradation products have been identified by GC-MS. The reaction rate constants and half-lives

  16. The occurrence of glyphosate, atrazine, and other pesticides in vernal pools and adjacent streams in Washington, DC, Maryland, Iowa, and Wyoming, 2005-2006

    USGS Publications Warehouse

    Battaglin, W.A.; Rice, K.C.; Focazio, M.J.; Salmons, S.; Barry, R.X.

    2009-01-01

    Vernal pools are sensitive environments that provide critical habitat for many species, including amphibians. These small water bodies are not always protected by pesticide label requirements for no-spray buffer zones, and the occurrence of pesticides in them is poorly documented. In this study, we investigated the occurrence of glyphosate, its primary degradation product aminomethylphosphonic acid, and additional pesticides in vernal pools and adjacent flowing waters. Most sampling sites were chosen to be in areas where glyphosate was being used either in production agriculture or for nonindigenous plant control. The four site locations were in otherwise protected areas (e.g., in a National Park). When possible, water samples were collected both before and after glyphosate application in 2005 and 2006. Twenty-eight pesticides or pesticide degradation products were detected in the study, and as many as 11 were identified in individual samples. Atrazine was detected most frequently and concentrations exceeded the freshwater aquatic life standard of 1.8 micrograms per liter (??g/l) in samples from Rands Ditch and Browns Ditch in DeSoto National Wildlife Refuge. Glyphosate was measured at the highest concentration (328 ??g/l) in a sample from Riley Spring Pond in Rock Creek National Park. This concentration exceeded the freshwater aquatic life standard for glyphosate of 65 ??g/l. Aminomethylphosphonic acid, triclopyr, and nicosulfuron also were detected at concentrations greater than 3.0 ??g/l. ?? Springer Science+Business Media B.V. 2008.

  17. ENANTIOMERIC COMPOSITION OF CHIRAL PESTICIDES IN HUMAN ADIPOSE TISSUE AND BREAST MILK

    EPA Science Inventory

    Examining the enantiomeric patterns of pesticides can provide a sensitive indicator of biological degradation. However, little work has been done to date on chiral pesticides in the human body. This study looks at the enantiomeric patterns of chiral pesticides and their chira...

  18. SOIL DEGRADATION

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil degradation can be defined as loss in the quality or productivity of soil, and is often the result of human activities, such as agriculture, deforestation, mining, waste disposal, or chemical spills. Degradation is attributed to changes in soil nutrient status, biota, loss of organic matter, d...

  19. Chromatographic determination of itopride hydrochloride in the presence of its degradation products.

    PubMed

    Kaul, Neeraj; Agrawal, Himani; Maske, Pravin; Rao, Janhavi Ramchandra; Mahadik, Kakasaheb Ramoo; Kadam, Shivajirao S

    2005-08-01

    Two sensitive and reproducible methods are described for the quantitative determination of itopride hydrochloride (IH) in the presence of its degradation products. The first method is based on HPLC separation on a reversed phase Kromasil column [C18 (5-microm, 25 cm x 4.6 mm, ID)] at ambient temperature using a mobile phase consisting of methanol and water (70:30, v/v) adjusted to pH 4.0 with orthophosphoric acid with UV detection at 258 nm. The flow rate was 1.0 mL per min with an average operating pressure of 180 kg/cm2. The second method is based on HPTLC separation on silica gel 60 F254 using toluene:methanol:chloroform:10% ammonia (5.0:3.0:6.0:0.1, v/v/v/v) as mobile phase at 270 nm. The analysis of variance (ANOVA) and Student's t-test were applied to correlate the results of IH determination in dosage form by means of HPLC and HPTLC methods. The drug was subjected to acid and alkali hydrolysis, oxidation, dry heat, wet heat treatment, UV, and photodegradation. The proposed HPLC method was utilized to investigate the kinetics of the acidic, alkaline, and oxidative degradation processes at different temperatures and the apparent pseudo-first-order rate constant, half-life, and activation energy were calculated. In addition the pH-rate profile of degradation of IH in constant ionic strength buffer solutions in the pH range 2-11 was studied. PMID:16158999

  20. Degradation of organic compounds and production of activated species in Dielectric Barrier Discharges and Glidarc reactors

    E-print Network

    Cormier, Jean Marie; Khacef, Ahmed

    2008-01-01

    Major sterilization mechanisms are related to atoms and radicals, charged parti-cles, excited molecules, ozone, and UV radiation. The ROS (Reactive Oxygen Species) are well known as evildoers. These species are easily created in ambient air and water and they live long enough to reach the cell and attack the organic matter. Test molecules conversion in dry and wet air is studied using Dielectric Barrier Discharge (DBD) and Gliding Arc Reactors (GAR). The effects of tem-perature and energy deposition into the media on the active species production and then on the organic compounds degradation are presented for two non thermal plasma reactors: DBD and GAR. Main production species investigated are OH, O3, NOx, CO and CxHyOz by-products. It is shown from experiment analysis that the reactive species production is quite different from one reactor to another. GAR and pulsed DBD are two chemical processing ways in which the temperature of heavy species in ionized gas is determinant. By reviewing the species producti...

  1. Dextranase: hyper production of dextran degrading enzyme from newly isolated strain of Bacillus licheniformis.

    PubMed

    Zohra, Rashida Rahmat; Aman, Afsheen; Zohra, Raheela Rahmat; Ansari, Asma; Ghani, Maria; Qader, Shah Ali Ul

    2013-02-15

    Dextranase, 6-alpha-D-glucan 6-glucanohydrolase catalyzes the degradation of dextran (polymer of D-glucose) in to low molecular weight fractions. Dextranolytic bacterial strains were isolated from various natural sources and plate assay methods were developed for screening of highest extracellular dextranase producing isolate. Bacillus licheniformis, identified on the basis of taxonomic characterization was subjected to UV radiation and highest enzyme producing mutant obtained led to 7 times more dextranase production than wild. Optimization of major physico-chemical parameters affecting enzyme production; including medium composition, pH, cultivation time and temperature revealed that maximum enzyme production was obtained in a self designed medium (pH 6.0) containing 1% Dextran 5000 Da, after 24 h culture incubation at 37 °C. Dextranase reported in this study is of great commercial importance as it is strictly inducible in nature and B. licheniformis being non-pathogenic removes the safety concerns associated with production of dextran fractions for clinical and pharmaceutical usage. PMID:23399270

  2. Degradation products from consumer nanocomposites - a case study on quantum dot lighting

    PubMed Central

    Liu, Jingyu; Katahara, John; Li, Guanglai; Coe-Sullivan, Seth; Hurt, Robert H.

    2012-01-01

    Most nanomaterials enter the natural environment as nano-enabled products, which are typically composites with primary nanoparticles bound on substrates or embedded in liquid or solid matrices. The environmental risks associated with these products are expected to differ from those associated with the as-produced particles. This article presents a case study on the end-of-life emission of a commercial prototype polymer/quantum-dot (QD) composite used in solid-state lighting for homes. We report the extent of cadmium release upon exposure to a series of environmental and biological simulant fluids, and track the loss of QD-characteristic fluorescence as a marker for chemical damage to the CdSe/ZnS nanoparticles. Measured cadmium releases after 30-day exposure range from 0.007-1.2 mg/g of polymer, and the higher values arise for low-pH simulants containing nitric or gastric acid. Centrifugal ultrafiltration and ICP was used to distinguish soluble cadmium from particulate forms. The leachate is found to contain soluble metals with no evidence of free QDs or QD-containing polymeric debris. The absence of free nanoparticles suggests that this product does not raise nanotechnology-specific environmental issues associated with degradation and leaching, but is more usefully regarded as a conventional chemical product that is a potential source of small amounts of soluble cadmium. PMID:22352378

  3. Fluorescence formation from the interaction of DNA with lipid oxidation degradation products.

    PubMed

    Frankel, E N; Neff, W E; Brooks, D D; Fujimoto, K

    1987-06-23

    To clarify the mechanism of fluorescence formation between DNA and lipid degradation products in the presence of ferric chloride and ascorbic acid, a number of carbonyl compounds and decomposition products of pure methyl linolenate hydroperoxides were examined. Keto derivatives of methyl ricinoleate, linoleate, and oleate, alkanals and 2-alkenals produced little or no fluorescence with DNA in the presence of ferric chloride-ascorbic acid. 2,4-Alkadienals were more active and 2,4,7-decatrienal was the most active. Mixtures of volatile aldehydes prepared from linolenate hydroperoxide decomposed either thermally or with iron and ascorbate had the same activity as 2,4,7-decatrienal. Higher molecular-weight products from the decomposition of methyl linolenate hydroperoxides showed relatively low activity. beta-Carotene, alpha-tocopherol and other antioxidants effectively reduced the amount of fluorescence formed by linolenate hydroperoxides. The results suggest that, in addition to hydroperoxide decomposition products, singlet oxygen and/or free radical species contribute significantly to the fluorescence formed from the interaction of methyl linolenate hydroperoxides with DNA in the presence of ferric chloride and ascorbic acid. PMID:3593747

  4. Pesticide exposure and sprayer's task goals: comparison between vineyards and

    E-print Network

    Pesticide exposure and sprayer's task goals: comparison between vineyards and greenhouses. Mandy of pesticide spraying. The objective of this intervention was to identify factors explaining the influence of crops is dependent on the use of pesticides. Plant protection products (PPP) are active substances

  5. SOURCE ASSESSMENT: PESTICIDE MANUFACTURING AIR EMISSIONS--OVERVIEW AND PRIORITIZATION

    EPA Science Inventory

    The report is an overview of the pesticide manufacturing industry and prioritizes 80 major pesticides based on their potential environmental burden from an air pollution standpoint. Production of synthetic organic pesticides was about 640,000 metric tons in 1974. Thirty-seven maj...

  6. Pesticide residues survey in citrus fruits

    Microsoft Academic Search

    Didier Ortelli; Patrick Edder; Claude Corvi

    2005-01-01

    The use of pesticides is widespread in citrus fruits production for pre- and post-harvest protection and many chemical substances may be applied in order to control undesirable moulds or insects. A survey was carried out to evaluate levels of pesticide residues in citrus fruits. Two multiresidue analytical methods were used to screen samples for more than 200 different fungicides, insecticides

  7. A survey of pesticide application in Cameroon

    Microsoft Academic Search

    G Matthews; T Wiles; P Baleguel

    2003-01-01

    Surveys of those applying pesticides in Cameroon was made as an initial part of a programme to introduce the adoption of minimum requirements for pesticide application equipment as the initial part of a programme for the sustainable improvement of rural workers and family health, to protect the environment and improve crop production efficiency. The survey considered those growing cocoa, coffee,

  8. Identification and Characterization of an Oxidative Degradation Product of Fexofenadine, Development and Validation of a Stability-Indicating RP-UPLC Method for the Estimation of Process Related Impurities and Degradation Products of Fexofenadine in Pharmaceutical Formulations

    PubMed Central

    Vaghela, Bhupendrasinh; Rao, Surendra Singh; Reddy, Annarapu Malleshwar; Venkatesh, Panuganti; Kumar, Navneet

    2012-01-01

    A novel stability-indicating gradient RP-UPLC method was developed for the quantitative determination of process related impurities and forced degradation products of fexofenadine HCl in pharmaceutical formulations. The method was developed by using Waters Aquity BEH C18 (100 mm x 2.1 mm) 1.7 ?m column with mobile phase containing a gradient mixture of solvent A (0.05% triethyl amine, pH adjusted to 7.0 with ortho-phosphoric acid) and B (10:90 v/v mixture of water and acetonitrile). The flow rate of mobile phase was 0.4 mL/min with column temperature of 30°C and detection wavelength at 220nm. Fexofenadine HCl was subjected to the stress conditions including oxidative, acid, base, hydrolytic, thermal and photolytic degradation. Fexofenadine HCl was found to degrade significantly in oxidative stress conditions, and degradation product was identified and characterized by ESI-MS/MS, 1H and 13C NMR spectroscopic method as the N-oxide 2-[4-(1-hydroxy-4-{4-[hydroxy(diphenyl)methyl]-1-oxido-piperidin-1-yl}butyl)phenyl]-2-methylpropanoic acid. The degradation products were well resolved from fexofenadine and its impurities. The mass balance was found to be satisfactory in all the stress conditions, thus proving the stability-indicating capability of the method. The developed method was validated as per ICH guidelines with respect to specificity, linearity, limit of detection and quantification, accuracy, precision and robustness. PMID:22896817

  9. Destruction of emulsions stabilized by precipitates of zirconium and tributyl phosphate degradation products

    SciTech Connect

    Sugai, H. (Sumitomo Metal Mining Co., Ltd., Tokai Research Center, 2600, Ishigamitojuku, Tokai-mura, Ibaraki-ken 319-11 (JP)); Munakata, K. (Sumitomo Metal Mining Co. Ltd., Ichikawa, Chiba (Japan). Central Research Lab.)

    1992-08-01

    In solvent extraction for nuclear fuel reprocessing, a stable emulsion called crud is formed at the interface between the organic and aqueous phases. Crud is an emulsion stabilized by finely dispersed solids. Process disturbances are often induced by crud. Accordingly, crud should be eliminated from the interface in the extractors. The eliminated crud is stable and highly radioactive; thus, the treatment of this crud may be difficult. Complexes of zirconium and tributyl phosphate (TBP) degradation products, such as phosphoric acid (H{sub 3}PO{sub 4}) and mono-n-butyl phosphate (H{sub 2}MBP), are one source of the fine particles that stabilize emulsions in the extraction process. In this paper a chemical treatment method to demulsify crud stabilized by precipitates of Zr-H{sub 3}PO{sub 4} and Zr-H{sub 2}MBP is studied.

  10. Crystalline degradation products of vancomycin as chiral stationary phase in microcolumn liquid chromatography.

    PubMed

    Ghassempour, Alireza; Alizadeh, Reza; Najafi, Nahid Mashkori; Karami, Ahmad; Römpp, Andreas; Spengler, Bernhard; Aboul-Enein, Hassan Y

    2008-07-01

    The ability of crystalline degradation products (CDPs) of vancomycin as a chiral stationary phase was reported in a previous study for enantioselective separation of drugs, amino acids and agrochemical toxins by conventional LC column (250 x 4.6 mm). In this work, the potential of CDP of vancomycin for the enantiomeric separation in micro-LC (200 x 1 mm) has been studied. The obtained separation results are better than in our previous study with conventional LC columns. The enantiomers of D,L-phenylalanine, D,L-alanine, methyldopa, atropine and propranolol were used for this evaluation. Experiments have been carried out in a stainless steel tube that was packed with chiral silica particles of 3 and 12 microm diameters. Also, three different ratios of 3 and 12 microm silica particles were used for packing material of chiral columns and the effect on aspect ratio and resolving powers was compared. PMID:18637659

  11. Solid supported in situ derivatization extraction of acidic degradation products of nerve agents from aqueous samples.

    PubMed

    Chinthakindi, Sridhar; Purohit, Ajay; Singh, Varoon; Tak, Vijay; Dubey, D K; Pardasani, Deepak

    2014-09-12

    This study deals with the solid supported in situ derivatization extraction of acidic degradation products of nerve agents present in aqueous samples. Target analytes were alkyl alkylphosphonic acids and alkylphosphonic acids, which are important environmental signatures of nerve agents. The method involved tert-butyldimethylchlorosilane mediated in situ silylation of analytes on commercially available diatomaceous solid phase extraction cartridges. Various parameters such as derivatizing reagent, its concentration, reaction time, temperature and eluting solvent were optimized. Recoveries of the analytes were determined by GC-MS which ranged from 60% to 86%. The limits of detection (LOD) and limit of quantification (LOQ) with selected analytes were achieved down to 78 and 213ngmL(-1) respectively, in selected ion monitoring mode. The successful applicability of method was also demonstrated on samples of biological origin such as plasma and to the samples received in 34th official proficiency test conducted by the Organization for Prohibition the of Chemical Weapons. PMID:25103280

  12. Analytical tools for the analysis of ?-carotene and its degradation products.

    PubMed

    Stutz, H; Bresgen, N; Eckl, P M

    2015-05-01

    ?-Carotene, the precursor of vitamin A, possesses pronounced radical scavenging properties. This has centered the attention on ?-carotene dietary supplementation in healthcare as well as in the therapy of degenerative disorders and several cancer types. However, two intervention trials with ?-carotene have revealed adverse effects on two proband groups, that is, cigarette smokers and asbestos-exposed workers. Beside other causative reasons, the detrimental effects observed have been related to the oxidation products of ?-carotene. Their generation originates in the polyene structure of ?-carotene that is beneficial for radical scavenging, but is also prone to oxidation. Depending on the dominant degradation mechanism, bond cleavage might occur either randomly or at defined positions of the conjugated electron system, resulting in a diversity of cleavage products (CPs). Due to their instability and hydrophobicity, the handling of standards and real samples containing ?-carotene and related CPs requires preventive measures during specimen preparation, analyte extraction, and final analysis, to avoid artificial degradation and to preserve the initial analyte portfolio. This review critically discusses different preparation strategies of standards and treatment solutions, and also addresses their protection from oxidation. Additionally, in vitro oxidation strategies for the generation of oxidative model compounds are surveyed. Extraction methods are discussed for volatile and non-volatile CPs individually. Gas chromatography (GC), (ultra)high performance liquid chromatography (U)HPLC, and capillary electrochromatography (CEC) are reviewed as analytical tools for final analyte analysis. For identity confirmation of analytes, mass spectrometry (MS) is indispensable, and the appropriate ionization principles are comprehensively discussed. The final sections cover analysis of real samples and aspects of quality assurance, namely matrix effects and method validation. PMID:25867077

  13. Blocking the Metabolism of Starch Breakdown Products in Arabidopsis Leaves Triggers Chloroplast Degradation

    PubMed Central

    Stettler, Michaela; Eicke, Simona; Mettler, Tabea; Messerli, Gaëlle; Hörtensteiner, Stefan; Zeeman, Samuel C.

    2009-01-01

    In most plants, a large fraction of photo-assimilated carbon is stored in the chloroplasts during the day as starch and remobilized during the subsequent night to support metabolism. Mutations blocking either starch synthesis or starch breakdown in Arabidopsis thaliana reduce plant growth. Maltose is the major product of starch breakdown exported from the chloroplast at night. The maltose excess 1 mutant (mex1), which lacks the chloroplast envelope maltose transporter, accumulates high levels of maltose and starch in chloroplasts and develops a distinctive but previously unexplained chlorotic phenotype as leaves mature. The introduction of additional mutations that prevent starch synthesis, or that block maltose production from starch, also prevent chlorosis of mex1. In contrast, introduction of mutations in disproportionating enzyme (DPE1) results in the accumulation of maltotriose in addition to maltose, and greatly increases chlorosis. These data suggest a link between maltose accumulation and chloroplast homeostasis. Microscopic analyses show that the mesophyll cells in chlorotic mex1 leaves have fewer than half the number of chloroplasts than wild-type cells. Transmission electron microscopy reveals autophagy-like chloroplast degradation in both mex1 and the dpe1/mex1 double mutant. Microarray analyses reveal substantial reprogramming of metabolic and cellular processes, suggesting that organellar protein turnover is increased in mex1, though leaf senescence and senescence-related chlorophyll catabolism are not induced. We propose that the accumulation of maltose and malto-oligosaccharides causes chloroplast dysfunction, which may by signaled via a form of retrograde signaling and trigger chloroplast degradation. PMID:19946617

  14. Toxicity measurement of orthopedic implant alloy degradation products using a bioluminescent bacterial assay.

    PubMed

    Shettlemore, M G; Bundy, K J

    1999-06-15

    The toxicity of aqueous metal solutions representative of ionic degradation products from orthopedic implant alloys was determined using a bacterial bioluminescence assay, Microtox. The toxicity of forms of the individual elements released from ASTM F75 Co-Cr-Mo (Co-Cr-Mo), F138 316L stainless steel (316L), and F136 Ti-6Al-4V (Ti-6Al-4V) was first determined, and a mathematical model was developed to predict the toxicity of mixtures of these ions. Aqueous metal solutions were then mixed according to the proportions of the ions found in these alloys, and their toxicity was measured with Microtox. Mixture behavior was classified as synergistic, antagonistic, or additive by comparing measured toxicity to predicted toxicity. Since relating these tests to actual implant corrosion processes can be confounded by selective leaching, the predicted and measured toxicity of aqueous metal solutions mixed according to proportions representative of selective leaching were next determined, and the mixture behaviors were classified as before. The most toxic individual alloying elements were found to be hexavalent Cr, Ni, and Co, in that order: a finding in accord with prior biocompatibility research. Co-Cr-Mo was found to be the most toxic alloy mixture of both those combined according to alloy composition and those combined to reflect selective leaching. The Ti-6Al-4V mixtures were found to behave synergistically, while the Co-Cr-Mo and 316L mixtures behaved antagonistically. By providing insight into degradation product toxicity and elemental interaction, these experiments demonstrate the utility of employing bioluminescent bacterial assays to investigate biocompatibility of implant materials. Further studies to more closely simulate in vivo conditions, though, are required to fully gauge their potential in this regard. PMID:10321713

  15. Study of the degradation products of bromopropylate, chlordimeform, coumaphos, cymiazole, flumethrin and tau-fluvalinate in aqueous media.

    PubMed

    Corta, E; Bakkali, A; Barranco, A; Berrueta, L A; Gallo, B; Vicente, F; Bogdanov, S

    2000-06-21

    Degradation processes of bromopropylate, coumaphos, chlordimeform, cymiazole, flumethrin and fluvalinate in aqueous media have been studied by HPLC. Cymiazole is stable at any tested pH (1-11), while bromopropylate, flumethrin and coumaphos are unstable at basic pH and chlordimeform and fluvalinate in neutral and basic media. The main degradation products have been identified by GC-MS. The reaction rate constants and half-lives were calculated and the effect of co-solvents on the rate and product profile was studied. PMID:18967974

  16. Application of high-performance liquid chromatography hyphenated techniques for identification of degradation products of cefpodoxime proxetil.

    PubMed

    Fukutsu, Naoto; Kawasaki, Takao; Saito, Koichi; Nakazawa, Hiroyuki

    2006-10-01

    Application of the HPLC hyphenated techniques of LC-MS, LC-NMR and solvent-elimination LC-IR was demonstrated by the identification of the degradation products of a third generation cephalosporin antibiotic, cefpodoxime proxetil, in solid state, drug formulation and solution. Molecular weight and fragment information were obtained by LC-MS, and detailed structural information was confirmed by LC-NMR. Information on the carboxyl functional group obtained by solvent-elimination LC-IR was useful for confirmation of the ester hydrolysis. The degradation products were successfully identified without complicated isolation or purification processes. PMID:16846608

  17. Release of anti-inflammatory peptides from thermosensitive nanoparticles with degradable cross-links suppresses pro-inflammatory cytokine production.

    PubMed

    Poh, Scott; Lin, Jenny B; Panitch, Alyssa

    2015-04-13

    Pro-inflammatory cytokines tumor necrosis factor ? (TNF-?) and interleukin 6 (IL-6) are mediators in the development of many inflammatory diseases. To demonstrate that macrophages take up and respond to thermosensitive nanoparticle drug carriers, we synthesized PEGylated poly(N-isopropylacrylamide-2-acrylamido-2-methyl-1-propanesulfonate) particles cross-linked with degradable disulfide (N,N'-bis(acryloyl)cystamine) (NGPEGSS). An anti-inflammatory peptide (KAFAK) was loaded and released from the thermosensitive nanoparticles and shown to suppress levels of TNF-? and IL-6 production in macrophages. Cellular uptake of fluorescent, thermosensitive, and degradable nanoparticles and therapeutic efficacy of free KAFAK peptide compared to that of KAFAK loaded in PEGylated degradable thermosensitive nanoparticles were examined. The data suggests that the degradable, thermosensitive nanoparticles loaded with KAFAK may be an effective tool to treat inflammatory diseases. PMID:25728363

  18. Heterologous expression of plant cell wall degrading enzymes for effective production of cellulosic biofuels.

    PubMed

    Jung, Sang-Kyu; Parisutham, Vinuselvi; Jeong, Seong Hun; Lee, Sung Kuk

    2012-01-01

    A major technical challenge in the cost-effective production of cellulosic biofuel is the need to lower the cost of plant cell wall degrading enzymes (PCDE), which is required for the production of sugars from biomass. Several competitive, low-cost technologies have been developed to produce PCDE in different host organisms such as Escherichia coli, Zymomonas mobilis, and plant. Selection of an ideal host organism is very important, because each host organism has its own unique features. Synthetic biology-aided tools enable heterologous expression of PCDE in recombinant E. coli or Z. mobilis and allow successful consolidated bioprocessing (CBP) in these microorganisms. In-planta expression provides an opportunity to simplify the process of enzyme production and plant biomass processing and leads to self-deconstruction of plant cell walls. Although the future of currently available technologies is difficult to predict, a complete and viable platform will most likely be available through the integration of the existing approaches with the development of breakthrough technologies. PMID:22911272

  19. Modelling the production and degradation of soluble microbial products (SMP) in membrane bioreactors (MBR).

    PubMed

    Jiang, Tao; Myngheer, Silvie; De Pauw, Dirk J W; Spanjers, Henri; Nopens, Ingmar; Kennedy, Maria D; Amy, Gary; Vanrolleghem, Peter A

    2008-12-01

    MBR biochemical conditions have an effect on membrane fouling and SMP have been attributed to be the main MBR foulant. Thus, predicting the SMP concentration is essential for understanding and controlling MBR fouling. However, existing SMP models are mostly too complex and over-parameterized, resulting in inadequate or absent parameter estimation and validation. This study extends the existing activated sludge model No. 2d (ASM2d) to ASM2dSMP with introduction of only 4 additional SMP-related parameters. Dynamic batch experimental results were used for SMP parameter estimation leading to reasonable parameter confidence intervals. Finally, the ASM2dSMP model was used to predict the impact of operational parameters on SMP concentration. It would found that solid retention time (SRT) is the key parameter controlling the SMP concentration. A lower SRT increased the utilization associated products (UAP) concentration, but decreased the biomass associated products (BAP) concentration and vice versa. A SRT resulting in minimum total SMP concentration can be predicted, and is found to be a relatively low value in the MBR. If MBRs operate under dynamic conditions and biological nutrient removal is required, a moderate SRT condition should be applied. PMID:18995881

  20. How agro-ecological research helps to address food security issues under new IPM and pesticide reduction policies for global crop production systems.

    PubMed

    E Birch, A Nicholas; Begg, Graham S; Squire, Geoffrey R

    2011-06-01

    Drivers behind food security and crop protection issues are discussed in relation to food losses caused by pests. Pests globally consume food estimated to feed an additional one billion people. Key drivers include rapid human population increase, climate change, loss of beneficial on-farm biodiversity, reduction in per capita cropped land, water shortages, and EU pesticide withdrawals under policies relating to 91/414 EEC. IPM (Integrated Pest Management) will be compulsory for all EU agriculture by 2014 and is also being widely adopted globally. IPM offers a 'toolbox' of complementary crop- and region-specific crop protection solutions to address these rising pressures. IPM aims for more sustainable solutions by using complementary technologies. The applied research challenge now is to reduce selection pressure on single solution strategies, by creating additive/synergistic interactions between IPM components. IPM is compatible with organic, conventional, and GM cropping systems and is flexible, allowing regional fine-tuning. It reduces pests below economic thresholds utilizing key 'ecological services', particularly biocontrol. A recent global review demonstrates that IPM can reduce pesticide use and increase yields of most of the major crops studied. Landscape scale 'ecological engineering', together with genetic improvement of new crop varieties, will enhance the durability of pest-resistant cultivars (conventional and GM). IPM will also promote compatibility with semiochemicals, biopesticides, precision pest monitoring tools, and rapid diagnostics. These combined strategies are urgently needed and are best achieved via multi-disciplinary research, including complex spatio-temporal modelling at farm and landscape scales. Integrative and synergistic use of existing and new IPM technologies will help meet future food production needs more sustainably in developed and developing countries, in an era of reduced pesticide availability. Current IPM research gaps are identified and discussed. PMID:21669880

  1. Biological, biochemical, and molecular parameters of Helisoma duryi snails exposed to the pesticides Malathion and Deltamethrin

    Microsoft Academic Search

    Fayez A. Bakry; Wafaa S. Hasheesh; Salwa A. H. Hamdi

    2011-01-01

    Aquatic environments get contaminated with pesticides residues that result from the application of pesticides in agricultural practices. The present study aimed to evaluate the pesticides Malathion and Deltamethrin on biological and biochemical parameters of Helisoma duryi snails. The results showed that LC10 of the two pesticides caused considerable reduction in survival rates and egg production of treated snails. Glucose concentration

  2. Degradation of nonylphenol polyethoxylates by ultraviolet B irradiation and effects of their products on mammalian cultured cells.

    PubMed

    Goto, Rensuke; Kubota, Toru; Ibuki, Yuko; Kaji, Kazuhiko; Goto, Ayako

    2004-10-01

    Nonylphenol polyethoxylates (NPEOs) are widely used as non-ionic surfactants and their biodegradation products such as 4-n-nonylphenol are stable and have been demonstrated to be cytotoxic. In the aquatic environment, these compounds are usually exposed to sunlight, and while the correlation between the biodegradation of NPEOs and changes in cytotoxicity has been reported, the relationship between the photodegradation of NPEOs and cytotoxicity has not. In this study, we investigated the degradation of NPEO by ultraviolet (UV) irradiation, especially UVB irradiation, and the effects on mammalian cell lines. NPEO with a smaller number of ethylene oxide (EO) units showed greater cytotoxicity. Although NPEO (10) completely inhibited the proliferation of the cells, NPEO (70) showed no toxicity. UVB irradiation significantly induced a shortening of the side chain, which was due to the production of ROS. The EO side chain of NPEO (10), was gradually degradated, but that of NPEO (70) was degradated near the benzene ring. Furthermore, the degradation of the benzene ring was more effective in NPEO (70) than NPEO (10). The toxicity of NPEO (10) in cultured cells decreased following UVB irradiation, whereas that of NPEO (70) was induced after UVB irradiation at 500 J/cm2 and disappeared at 1000 J/cm2. This might be due to the production of NPEO with a short side chain and 4-n-nonylphenol by the degradation of EO and due to the degradation of the benzene ring at higher doses of UVB irradiation. This study shows the significance of UV exposure to the degradation of alkylphenol polyethoxylates in the environment. PMID:15337586

  3. Scientists Probe Pesticide Dynamics

    ERIC Educational Resources Information Center

    Chemical and Engineering News, 1974

    1974-01-01

    Summarizes discussions of a symposium on pesticide environmental dynamics with emphases upon pesticide transport processes, environmental reactions, and partitioning in air, soil, water and living organisms. Indicates that the goal is to attain knowledge enough to predict pesticide behavior and describe pesticide distribution with models and…

  4. PESTICIDE INFORMATION NETWORK

    EPA Science Inventory

    The Pesticide Information Network (PIN) is an interactive database containing information about pesticides. PIN is a free service offered by the USEPAs Office of Pesticide Programs which provides contacts on pesticide issues, has a bulletin board network for public and private us...

  5. Estimating starch availability and protein degradation of steam-flaked and reconstituted sorghum grain through a gas production technique.

    PubMed

    Xiong, Y; Bartle, S J; Preston, R L; Meng, Q

    1990-11-01

    Five steam-flaked sorghum grain (SFSG) samples with bulk densities of 476, 412, 347, 309 and 283 g/liter made by adjusting tension between mill rollers and three reconstituted sorghum grain (RSG) samples with reconstitution times of 10, 20 and 30 d and a control sample were analyzed for gas production kinetics (rumen liquor fermentation) and enzymatic glucose release (amyloglucosidase). Protein degradation was estimated from 6-h gas production and residual ammonia in the liquid. Gas production followed first-order kinetics (r2 greater than .98; P less than .01) and was used to describe rate and extent of digestion kinetics. Rate of gas production increased as processing degree increased. The magnitude of increase in gas production, however, was much less for RSG than for SFSG. Linear relationships were observed between enzymatic glucose release and the gas production rate constant k as well as gas production at 4,6 and 8 h (r2 greater than .98; P less than .01). Protein degradation decreased with processing degree of SFSG but increased with reconstitution time. A technique based on 6-h gas production and residual ammonia in the liquid is proposed to estimate both ruminal starch availability and ruminal protein degradability for processed sorghum grain. PMID:2262434

  6. Surfactant effects on environmental behavior of pesticides.

    PubMed

    Katagi, Toshiyuki

    2008-01-01

    The potential effects of adjuvants, including surfactants used in pesticide formulation, have been extensively studied for many small organic chemicals, but similar investigation on pesticides is limited in most cases. Solubilizing effects leading to the apparently increased water solubility of a pesticide are commonly known through the preparation of formulations, but fundamental profiles, especially for a specific monodisperse surfactant, are not fully studied. Reduced volatilization of a pesticide from the formulation can be explained by analogy of a very simple organic chemical, but the actual mechanism for the pesticide is still obscure. In contrast, from the point of view of avoiding groundwater contamination with a pesticide, adsorption/desorption profiles in the presence of surfactants and adjuvants have been examined extensively as well as pesticide mobility in the soil column. The basic mechanism in micelle-catalyzed hydrolysis is well known, and theoretical approaches including the PPIE model have succeeded in explaining the observed effects of surfactants, but its application to pesticides is also limited. Photolysis, especially in an aqueous phase, is in the same situation. The dilution effect in the real environment would show these effects on hydrolysis and photolysis to be much less than expected from the laboratory basic studies, but more information is necessary to examine the practical extent of the effects in an early stage of applying a pesticide formulation to crops and soil. Many adjuvants, including surfactants, are biodegradable in the soil environment, and thus their effects on the biodegradation of a pesticide in soil and sediment may be limited, as demonstrated by field trials. Not only from the theoretical but also the practical aspect, the foliar uptake of pesticide in the presence of adjuvants has been investigated extensively and some prediction on the ease of foliar uptake can be realized in relation to the formulation technology. However, effect on root uptake of pesticides is to be further investigated. In an aqueous environment more or less contaminated by various chemicals such as detergents and their degradates, it is necessary to investigate the effect of adjuvants on uptake, bioconcentration, and trophic transfer of pesticides for better understanding of pesticide contamination of aquatic species in the aquatic environment. PMID:18069647

  7. The Geochemistry of Pesticides

    NASA Astrophysics Data System (ADS)

    Barbash, J. E.

    2003-12-01

    The mid-1970s marked a major turning point in human history, for it was at that moment that the ability of the Earth's ecosystems to absorb most of the biological impacts of human activities appears to have been exceeded by the magnitude of those impacts. This conclusion is based partly upon estimates of the rate of carbon dioxide emission during the combustion of fossil fuels, relative to the rate of its uptake by terrestrial ecosystems (Loh, 2002). A very different threshold, however, had already been crossed several decades earlier with the birth of the modern chemical industry, which produced novel substances for which no such natural assimilative capacity existed. Among these new chemical compounds, none has posed a greater challenge to the planet's ecosystems than synthetic pesticides, compounds that have been intentionally released into the hydrologic system in vast quantities - several hundred million pounds of active ingredient per year in the United States alone ( Donaldson et al., 2002) - for many decades. To gauge the extent to which we are currently able to assess the environmental implications of this new development in the Earth's history, this chapter presents an overview of current understanding regarding the sources, transport, fate and biological effects of pesticides, their transformation products, and selected adjuvants in the hydrologic system. (Adjuvants are the so-called "inert ingredients" included in commercial pesticide formulations to enhance the effectiveness of the active ingredients.)

  8. Mass fragmentographic determination of urinary amine metabolites in rats exposed to degradation products from heated rigid polyurethane.

    PubMed

    Rosenberg, C; Savolainen, H

    1986-05-23

    A mass fragmentographic method was developed for the urinalysis of amine metabolites in rats resulting from inhalation of thermally induced degradation products of rigid polyurethane synthesized from the aromatic diisocyanate 4,4'-bis(carbonylamino)diphenylmethane. The urinary excretion of acetylated 4,4'-bis(amino)-diphenylmethane was determined after acid hydrolysis, followed by alkaline extraction in toluene and derivatization with heptafluorobutyric acid anhydride. The excretion was linearly correlated to the inhaled parent isocyanate at three different degradation temperatures. Mass spectrometric detection of the amines also allowed comparison with the degraded polymer, which should be of considerable forensic significance. The sensitivity (5 pg/microliter) also enables biological monitoring of occupational exposure in the production and engineering of polyurethane articles. PMID:3745356

  9. Phytoremediation and Detoxification of Two Organophosphorous Pesticides Residues in Riyadh Area

    Microsoft Academic Search

    Fahd Al-Qurainy; Ahmed Abdel-Megeed

    2009-01-01

    A study was undertaken to detect and monitor the degradation of two organophosphorous pesticide residues (dimethoate and malathion) by four plants namely Amaranth, Amaranthus caudate, Lettuce, Lactuca sativa, Water cress, Nasturtium officinale and Kidney bean, Phaseolus vulgaris and microbial degradation based on the recommended rates for insects control in Kingdom of Saudi Arabia. Pesticides residues were quantified by gas chromatography

  10. Pesticide Fate and Transport throughout Unsaturated Zones in Five Agricultural Settings, USA

    Microsoft Academic Search

    Tracy C. Hancock; Mark W. Sandstrom; Jason R. Vogel; Richard M. T. Webb; E. Randall Bayless; Jack E. Barbash

    2008-01-01

    Pesticide transport through the unsaturated zone is a function of chemical and soil characteristics, application, and water recharge rate. Th e fate and transport of 82 pesticides and degradates were investigated at fi ve diff erent agricultural sites. Atrazine and metolachlor, as well as several of the degradates of atrazine, metolachlor, acetochlor, and alachlor, were frequently detected in soil water

  11. Wet deposition of pesticides and nitrophenols at two sites in Denmark: measurements and contributions from regional sources.

    PubMed

    Asman, Willem A H; Jørgensen, Andreas; Bossi, Rossana; Vejrup, Karl V; Mogensen, Betty Bügel; Glasius, Marianne

    2005-05-01

    The concentrations of selected pesticides, of some of their degradation products and nitrophenols in rain were measured at two stations in Denmark in the period January 2000-July 2001. Forty compounds were quantified at least at one station during at least one sampling period. Additionally 17 compounds could be detected but not quantified, and 22 compounds could not be detected at all. The highest depositions of pesticides were observed for pendimethalin and desethylterbuthylazine, which is a degradation product of terbuthylazine. The deposition of the nitrophenols 2,4-dinitrophenol, DNOC, 3-methyl-4-nitrophenol was much higher than that of pesticides. The deposition of 2,4-dinitrophenol was e.g. up to a factor of 40 higher than that of pendimethalin. Atrazine, chloridazon, 2,4-D, dieldrin, disulfoton, fenitrothion, isoproturon, lenacil, metazachlor and propachlor were found in precipitation, although these pesticides are not allowed in Denmark. It can therefore be concluded that they came from abroad and have been transported over at least 60-80 km. For some of these compounds the transport distance is much longer. PMID:15823336

  12. Quantification of Plasma Fibrinogen Degradation Products in Areca Nut Chewers with and without Oral Submucous Fibrosis

    PubMed Central

    SM, Manjunath; Jawanda, Manveen Kaur; Bharti, Achla

    2014-01-01

    Introduction: Fibrinogen degradation products (FDPs) are the products that are released from fibrin/fibrinogen. Recently, it has been observed that these FDPs have been identified in the plasma of OSMF patients. Areca nut being the major aetiological agent for OSMF may play a role in the increased plasma levels of FDPs in OSMF. Aim: The aim of this study was to quantify the plasma FDPs levels in the individuals with the habit of areca nut chewing with and without OSMF. Materials & Methods: Total of 95 subjects were included,35 subjects with the habit of areca nut chewing with OSMF, 30 with the habit of areca nut chewing without OSMF, 30 without any habit of areca nut chewing without OSMF (control group). Five ml of venous blood was withdrawn from all the subjects and plasma FDP levels were estimated. Results: Plasma FDPs were detected in all the subjects of OSMF but could not be detected in other two groups. As the clinical grades of OSMF increased, levels of plasma FDPs also increased. Conclusion: When plasma FDP increases, fibrin deposition also increases. This strengthens the finding that these FDPs may be an early indicator of the OSMF. PMID:25584311

  13. A review of methods for the analysis of orphan and difficult pesticides: glyphosate, glufosinate, quaternary ammonium and phenoxy acid herbicides, and dithiocarbamate and phthalimide fungicides.

    PubMed

    Raina-Fulton, Renata

    2014-01-01

    This article reviews the chromatography/MS methodologies for analysis of pesticide residues of orphan and difficult chemical classes in a variety of sample matrixes including water, urine, blood, and food. The review focuses on pesticide classes that are not commonly included in multiresidue analysis methods such as highly polar or ionic herbicides including glyphosate, glufosinate, quaternary ammonium, and phenoxy acid herbicides, and some of their major degradation or metabolite products. In addition, dithiocarbamate and phthalimide fungicides, which are thermally unstable and have stability issues in some solvents or sample matrixes, are also examined due to their special needs in residue analysis. PMID:25145125

  14. Studies on dodecyl betainate in combination with its degradation products or with phosphatidyl choline–phase behavior and hemolytic activity

    Microsoft Academic Search

    D. Lundberg; H. Ljusberg-Wahren; A. Norlin; K. Holmberg

    2004-01-01

    Surface active betaine esters contain a hydrolysable bond and give naturally occurring products (fatty alcohol and the amino acid betaine) on degradation. They are therefore interesting candidates for use as cationic surfactants in pharmaceutical applications. In this work the phase behavior of two systems of relevance for the utilization of dodecyl betainate as a pharmaceutical excipient is studied, namely dodecyl

  15. Strategies to alleviate poverty and grassland degradation in Inner Mongolia: intensification vs production efficiency of livestock systems.

    PubMed

    Briske, David D; Zhao, Mengli; Han, Guodong; Xiu, Changbai; Kemp, David R; Willms, Walter; Havstad, Kris; Kang, Le; Wang, Zhongwu; Wu, Jianguo; Han, Xingguo; Bai, Yongfei

    2015-04-01

    Semi-nomadic pastoralism was replaced by sedentary pastoralism in Inner Mongolia during the 1960's in response to changes in land use policy and increasing human population. Large increases in numbers of livestock and pastoralist households (11- and 9-fold, respectively) during the past 60 yrs have variously degraded the majority of grasslands in Inner Mongolia (78 M ha) and jeopardize the livelihoods of 24 M human inhabitants. A prevailing strategy for alleviating poverty and grassland degradation emphasizes intensification of livestock production systems to maintain both pastoral livelihoods and large livestock numbers. We consider this strategy unsustainable because maximization of livestock revenue incurs high supplemental feed costs, marginalizes net household income, and promotes larger flock sizes to create a positive feedback loop driving grassland degradation. We offer an alternative strategy that increases both livestock production efficiency and net pastoral income by marketing high quality animal products to an increasing affluent Chinese economy while simultaneously reducing livestock impacts on grasslands. We further caution that this strategy be designed and assessed within a social-ecological framework capable of coordinating market expansion for livestock products, sustainable livestock carrying capacities, modified pastoral perceptions of success, and incentives for ecosystem services to interrupt the positive feedback loop that exists between subsistence pastoralism and grassland degradation in Inner Mongolia. PMID:25687702

  16. The sfe Maize Mutant: Reduced Ferulate Cross Linking Improves Rumen Cell Wall Degradability and Milk Production by Dairy Cows

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A putative mutant has been identified in maize that reduces ferulate cross linking of lignin to arabinoxylan in mature stover, increases in vitro rumen cell wall degradability, and increases milk production by cows. The seedling ferulate ester (sfe) mutant was discovered in a Mu transposon-mutated p...

  17. Microbial surface displayed enzymes based biofuel cell utilizing degradation products of lignocellulosic biomass for direct electrical energy.

    PubMed

    Fan, Shuqin; Hou, Chuantao; Liang, Bo; Feng, Ruirui; Liu, Aihua

    2015-09-01

    In this work, a bacterial surface displaying enzyme based two-compartment biofuel cell for the direct electrical energy conversion from degradation products of lignocellulosic biomass is reported. Considering that the main degradation products of the lignocellulose are glucose and xylose, xylose dehydrogenase (XDH) displayed bacteria (XDH-bacteria) and glucose dehydrogenase (GDH) displayed bacteria (GDH-bacteria) were used as anode catalysts in anode chamber with methylene blue as electron transfer mediator. While the cathode chamber was constructed with laccase/multi-walled-carbon nanotube/glassy-carbon-electrode. XDH-bacteria exhibited 1.75 times higher catalytic efficiency than GDH-bacteria. This assembled enzymatic fuel cell exhibited a high open-circuit potential of 0.80V, acceptable stability and energy conversion efficiency. Moreover, the maximum power density of the cell could reach 53?Wcm(-2) when fueled with degradation products of corn stalk. Thus, this finding holds great potential to directly convert degradation products of biomass into electrical energy. PMID:26051524

  18. Improved chromatographic method for the simultaneous determination of ten phenylurea herbicides and some of their degradation products in soil

    Microsoft Academic Search

    Bernhard Berger

    1997-01-01

    A new analytical method is presented for the simultaneous determination of ten phenylureas and six degradation products. This is the first multiresidue method for these herbicides that includes the most prominent metabolites in soil, the monodesalkyl derivatives and, therefore, complements and improves existing methods. After extraction, the compounds are separated on two coupled columns with Nucleosil-100 C18, 3 ?m with

  19. Metabolic engineering of yeasts by heterologous enzyme production for degradation of cellulose and hemicellulose from biomass: a perspective

    PubMed Central

    Kricka, William; Fitzpatrick, James; Bond, Ursula

    2014-01-01

    This review focuses on current approaches to metabolic engineering of ethanologenic yeast species for the production of bioethanol from complex lignocellulose biomass sources. The experimental strategies for the degradation of the cellulose and xylose-components of lignocellulose are reviewed. Limitations to the current approaches are discussed and novel solutions proposed. PMID:24795706

  20. Estimating rumen degradability of forages from semi-natural grasslands, using nylon bag and gas production techniques

    Microsoft Academic Search

    M. H. Bruinenberg; A. H. Van Gelder; P. Gonzalez Perez; V. A. Hindle; J. W. Cone

    2004-01-01

    To obtain insight into ruminal digestion of forages from extensively managed semi-natural grasslands, degradation characteristics and kinetics of silages of three different forages in the rumen of lactating dairy cows were estimated in vitro, using the gas production technique (GPT), and in situ, using the nylon bag technique. Silages originated from intensively managed grassland (IMG), extensively managed species-poor grassland (SPP)

  1. MESOTHELIAL TOXICITY OF PERITONEAL DIALYSIS FLUIDS IS RELATED PRIMARILY TO GLUCOSE DEGRADATION PRODUCTS, NOT TO GLUCOSE PER SE

    Microsoft Academic Search

    Janusz Witowski; Thorsten O. Bender; Justyna Wisniewska-Elnur; Krzysztof Ksiazek; Jutta Passlick-Deetjen; Andrzej Breborowicz; Achim Jörres

    • Objectives: High concentrations of glucose and\\/or formation of glucose degradation products (GDPs) dur- ing heat sterilization of peritoneal dialysis fluids (PDFs) are believed to be key factors in the limited biocom- patibility of PDFs. We have previously shown that sev- eral identified GDPs can specifically impair human peritoneal mesothelial cell (HPMC) function. In the present study we aimed at

  2. Comparison of plastic types for catalytic degradation of waste plastics into liquid product with spent FCC catalyst

    Microsoft Academic Search

    Kyong-Hwan Lee; Nam-Sun Noh; Dae-Hyun Shin; Younghwa Seo

    2002-01-01

    The catalytic degradation of waste plastics such as polyethylene (HDPE, LDPE), polypropylene (PP) and polystyrene (PS) over spent fluid catalytic cracking (FCC) catalyst was carried out at atmospheric pressure with a stirred semi-batch operation at 400 °C using the same reaction temperature programming. The objective was to investigate the influence of plastic types on the yield, liquid product rate and liquid

  3. Emergy analysis of ethanol production from low-input, high-diversity (LIHD) grasslands on degraded farmland

    Microsoft Academic Search

    Robert A. Urban; Bhavik R. Bakshi

    2011-01-01

    This research aims to analyze ethanol production from lignocellulosic biomass produced from low-input, high- diversity (LIHD) grasslands (often referred to as prairies) on degraded farmland by applying the principles of emergy analysis. This type of cellulosic biomass is an attractive alternative to traditional monocultural biomass sources such as corn because it requires less purchased inputs in the agricultural phase and

  4. Progressive Degradation of Crude Oil n-Alkanes Coupled to Methane Production under Mesophilic and Thermophilic Conditions

    PubMed Central

    Cheng, Lei; Shi, Shengbao; Li, Qiang; Chen, Jianfa; Zhang, Hui; Lu, Yahai

    2014-01-01

    Although methanogenic degradation of hydrocarbons has become a well-known process, little is known about which crude oil tend to be degraded at different temperatures and how the microbial community is responded. In this study, we assessed the methanogenic crude oil degradation capacity of oily sludge microbes enriched from the Shengli oilfield under mesophilic and thermophilic conditions. The microbial communities were investigated by terminal restriction fragment length polymorphism (T-RFLP) analysis of 16S rRNA genes combined with cloning and sequencing. Enrichment incubation demonstrated the microbial oxidation of crude oil coupled to methane production at 35 and 55°C, which generated 3.7±0.3 and 2.8±0.3 mmol of methane per gram oil, respectively. Gas chromatography-mass spectrometry (GC-MS) analysis revealed that crude oil n-alkanes were obviously degraded, and high molecular weight n-alkanes were preferentially removed over relatively shorter-chain n-alkanes. Phylogenetic analysis revealed the concurrence of acetoclastic Methanosaeta and hydrogenotrophic methanogens but different methanogenic community structures under the two temperature conditions. Candidate divisions of JS1 and WWE 1, Proteobacteria (mainly consisting of Syntrophaceae, Desulfobacteraceae and Syntrophorhabdus) and Firmicutes (mainly consisting of Desulfotomaculum) were supposed to be involved with n-alkane degradation in the mesophilic conditions. By contrast, the different bacterial phylotypes affiliated with Caldisericales, “Shengli Cluster” and Synergistetes dominated the thermophilic consortium, which was most likely to be associated with thermophilic crude oil degradation. This study revealed that the oily sludge in Shengli oilfield harbors diverse uncultured microbes with great potential in methanogenic crude oil degradation over a wide temperature range, which extend our previous understanding of methanogenic degradation of crude oil alkanes. PMID:25409013

  5. Progressive degradation of crude oil n-alkanes coupled to methane production under mesophilic and thermophilic conditions.

    PubMed

    Cheng, Lei; Shi, Shengbao; Li, Qiang; Chen, Jianfa; Zhang, Hui; Lu, Yahai

    2014-01-01

    Although methanogenic degradation of hydrocarbons has become a well-known process, little is known about which crude oil tend to be degraded at different temperatures and how the microbial community is responded. In this study, we assessed the methanogenic crude oil degradation capacity of oily sludge microbes enriched from the Shengli oilfield under mesophilic and thermophilic conditions. The microbial communities were investigated by terminal restriction fragment length polymorphism (T-RFLP) analysis of 16S rRNA genes combined with cloning and sequencing. Enrichment incubation demonstrated the microbial oxidation of crude oil coupled to methane production at 35 and 55°C, which generated 3.7±0.3 and 2.8±0.3 mmol of methane per gram oil, respectively. Gas chromatography-mass spectrometry (GC-MS) analysis revealed that crude oil n-alkanes were obviously degraded, and high molecular weight n-alkanes were preferentially removed over relatively shorter-chain n-alkanes. Phylogenetic analysis revealed the concurrence of acetoclastic Methanosaeta and hydrogenotrophic methanogens but different methanogenic community structures under the two temperature conditions. Candidate divisions of JS1 and WWE 1, Proteobacteria (mainly consisting of Syntrophaceae, Desulfobacteraceae and Syntrophorhabdus) and Firmicutes (mainly consisting of Desulfotomaculum) were supposed to be involved with n-alkane degradation in the mesophilic conditions. By contrast, the different bacterial phylotypes affiliated with Caldisericales, "Shengli Cluster" and Synergistetes dominated the thermophilic consortium, which was most likely to be associated with thermophilic crude oil degradation. This study revealed that the oily sludge in Shengli oilfield harbors diverse uncultured microbes with great potential in methanogenic crude oil degradation over a wide temperature range, which extend our previous understanding of methanogenic degradation of crude oil alkanes. PMID:25409013

  6. Only low methane production and emission in degraded peat extraction sites after rewetting

    NASA Astrophysics Data System (ADS)

    Agethen, Svenja; Waldemer, Carolin; Knorr, Klaus-Holger

    2015-04-01

    In Central Europe rewetting of bogs after peat extraction is a wide spread technique to halt secondary aerobic decomposition and to reestablish plant species such as Sphagnum spp. and Eriophorum spp. that initialize accumulation of organic carbon in peat. Before extraction, such sites are often used for agriculture causing the aerobic degradation of peat and mobilization of phosphorus, ammonia, and dissolved organic matter (DOM). In nutrient poor ecosystems such as bogs, additional supply of P and N does not only trigger the establishment of uncharacteristic vegetation but also the formation of more labile plant litter and DOM that is readily degradable. Therefore, after rewetting and the development of anoxic conditions especially in initial stages high methane (CH4) emissions are reported for these systems compared to pristine bogs. Regarding the potential of methane production and emissions we investigated three common practices to prepare extraction fields for restoration (years since rewetting): i) Filling of drainage ditches, passive rewetting (1 site, Altendorfer Moor, Stade, NW-Germany, ca. 20 yr.), ii) Removal of upper 30 cm peat layer, removed peat used for construction of polder dikes (2 sites, Königsmoor, Leer, NW-Germany, 2 and 3 yr.), iii) Removal upper peat layer down to 50 cm grown peat, not extracted peat used as polder walls (2 sites, Benthullener Moor, Wardenburg, NW-Germany, 3 and 7 yr.). In each site two vegetated replicate mesocosms (diam. 30 cm, depth 40 cm) were sampled and placed in a greenhouse from May-October 2014 to maintain the water table at surface level. Pore water concentrations of ions, fermentation products and DOM, DOM electron acceptor capacity (EAC), soil gas concentrations of CO2, CH4 and H2, gas fluxes as well as element composition and organic matter quality of DOM and SOM were analyzed. We found out that practice i) with least efforts of nutrient removal in the peat produced the highest CH4 emissions (3.5 mmol m-2 d-1) although still within the range of northern pristine bogs. Also practice ii) showed still inputs of external nutrients and labile DOM, but CH4 production was not yet developed (0.23 and 0.07 mmol m-2 d-1). Practice iii) was most effective in nutrient removal, but only in the 7 yr. site little methane (in the 3 yr. site 0.025 vs. 0.41 mmol m-2 d-1in the 7 yr. site) was emitted. The emissions were well in accord with soil gas concentrations, maximum values for CH4 in practice i) were 115 ?mol L-1, 2-5 ?mol L-1 in practice ii) and 0.5 vs. 16 ?mol L-1 in practice iii). Only small concentrations of inorganic electron acceptors such as sulfate imply the importance of organic matter as electron acceptor. The results show that restored bogs on former strongly degraded extraction fields do not necessarily act as exceptionally high CH4 sources. Contrary to other findings in early stages of rewetting CH4 emissions can also be very low until other electron acceptors are exhausted and methanogens become effective competitors for substrates which happens in the order of years.

  7. Production and partial characterization of arabinoxylan-degrading enzymes by Penicillium brasilianum under solid-state fermentation

    Microsoft Academic Search

    Gianni Panagiotou; Pierre Granouillet; Lisbeth Olsson

    2006-01-01

    The production of a battery of arabinoxylan-degrading enzymes by the fungus Penicillium brasilianum grown on brewer’s spent grain (BSG) under solid-state fermentation was investigated. Initial moisture content, initial pH, temperature, and nitrogen source content were optimized to achieve maximum production of feruloyl esterase, xylanase, and ?-l-arabinofuranosidase. Under the optimum growth conditions (80% moisture, pH 6, 26.5C, and 5 g\\/l nitrogen source), the

  8. A comparative study of liquid product on non-catalytic and catalytic degradation of waste plastics using spent FCC catalyst

    Microsoft Academic Search

    Kyong-Hwan Lee; Dae-Hyun Shin

    2006-01-01

    Non-catalytic and catalytic degradation of waste plastics (high-density polyethylene (HDPE), low-density polyethylene (LDPE),\\u000a polypropylene (PP) and polystyrene (PS)) using spent fluid catalytic cracking (FCC) catalyst into liquid product were comparatively\\u000a studied with a stirred semi-batch reactor at 400 ‡C, under nitrogen stream. Liquid product characteristics were described\\u000a by cumulative distribution as a function of lapse time of reaction, paraffin, olefin,

  9. Imprinted sol-gel materials for monitoring degradation products in automotive oils by shear transverse wave.

    PubMed

    Mujahid, Adnan; Afzal, Adeel; Glanzing, Gerd; Leidl, Anton; Lieberzeit, Peter A; Dickert, Franz L

    2010-08-18

    Titania sol-gel layers imprinted with capric acid have been used as synthetic receptors for highly sensitive detection of oxidized products resulting from degradation of automotive engine oil. These layers have been applied as sensitive coating material on shear transverse wave (STW) resonators of frequencies ranging from 100 MHz to 430 MHz. A relatively small size of STW resonators, i.e. about 2 mm for 430 MHz makes these devices extremely useful while considering the concept of miniaturization. It has been proved experimentally that by increasing fundamental resonance frequency of these devices, a very high sensor response i.e. 22 kHz up to 460 kHz can be generated. The geometry of long chain capric acid fits best as recognition element in the synthesis of imprinted TiO(2) network. The thin titania layers coated on transducer surface provide excellent diffusion pathways to oxidized products of waste engine oil for selective and reversible re-inclusion i.e. recovery time of 30 min. Viscosity effects of oxidized engine oil can be minimized by shear waves which do not dissipate considerable amount of energy that ensure smooth liquid phase operation. Different oxidized products i.e. carbonic acids and esters can be characterized in lubricant via infra-red (IR) spectroscopy. The increasing IR absorbance of different waste oil samples is a clear indication of increasing concentration of carbonyl group. The IR absorbance of carbonyl groups is directly correlated to the age of respective waste engine oil samples and a quantitative relationship between sensor responses from STWs and IR absorbance was also developed. PMID:20708116

  10. Production of Exopolysaccharide by Lactobacillus rhamnosus R and Analysis of Its Enzymatic Degradation during Prolonged Fermentation

    PubMed Central

    Pham, P. L.; Dupont, I.; Roy, D.; Lapointe, G.; Cerning, J.

    2000-01-01

    The potential of Lactobacillus rhamnosus R for producing exopolysaccharide (EPS) when grown on basal minimum medium supplemented with glucose or lactose was investigated. EPS production by L. rhamnosus R is partially growth associated and about 500 mg of EPS per liter was synthesized with both sugars. The product yield coefficient (YEPS/S) was 3.15 (0.0315 g of EPS [g of lactose]?1) and 2.88 (0.0288 g of EPS [g of glucose]?1). It was clearly shown that the amount of EPS produced declined upon prolonged fermentation. Degradation of EPS in fermentation processes was also assessed by measuring its molecular weights and viscosities. As these reductions might have a negative effect on the yield and viscosifying properties of EPS, it was essential to examine possible causes related to this breakdown. The decrease in viscosities and molecular weights of EPS withdrawn at different cultivation times permitted us to suspect the presence of a depolymerizing enzyme in the fermentation medium. Our study on enzymatic production profiles showed a large spectrum of glycohydrolases (?-d-glucosidase, ?-d-glucosidase, ?-d-galactosidase, ?-d-galactosidase, ?-d-glucuronidase, and some traces of ?-l-rhamnosidase). These enzymes were localized, two of them (?-d-glucosidase and ?-d-glucuronidase) were partially purified and characterized. When incubated with EPS, these enzymes were capable of lowering the viscosity of the polymer as well as liberating some reducing sugars. Upon prolonged incubation (27 h), the loss of viscosity was increased up to 33%. PMID:10831403

  11. Contribution of hydroxylated atrazine degradation products to the total atrazine load in midwestern streams

    USGS Publications Warehouse

    Lerch, R.N.; Blanchard, P.E.; Thurman, E.M.

    1998-01-01

    The contribution of hydroxylated atrazine degradation products (HADPs) to the total atrazine load (i.e., atrazine plus stable metabolites)in streams needs to be determined in order to fully assess the impact of atrazine contamination on stream ecosystems and human health. The objectives of this study were (1) to determine the contribution of HADPs to the total atrazine load in streams of nine midwestern states and (2) to discuss the mechanisms controlling the concentrations of HADPs in streams. Stream samples were collected from 95 streams in northern Missouri at preplant and postplant of 1994 and 1995, and an additional 46 streams were sampled in eight midwestern states at postplant of 1995. Samples were analyzed for atrazine, deethylatrazine (DEA), deisopropylatrazine (DIA), and three HADPs. Overall, HADP prevalence (i.e., frequency of detection) ranged from 87 to 100% for hydroxyatrazine (HA), 0 to 58% for deethylhydroxyatrazine (DEHA), and 0% for deisopropylhydroxyatrazine (DIHA) with method detection limits of 0.04-0.10 ??g L-1. Atrazine metabolites accounted for nearly 60% of the atrazine load in northern Missouri streams at preplant, with HA the predominant metabolite present. Data presented in this study and a continuous monitoring study are used to support the hypothesis that a combination of desorption from stream sediments and dissolved-phase transport control HADP concentrations in streams.The contribution of hydroxylated atrazine degradation products (HADPs) to the total atrazine load (i.e., atrazine plus stable metabolites) in streams needs to be determined in order to fully assess the impact of atrazine contamination on stream ecosystems and human health. The objectives of this study were (1) to determine the contribution of HADPs to the total atrazine load in streams of nine midwestern states and (2) to discuss the mechanisms controlling the concentrations of HADPs in streams. Stream samples were collected from 95 streams in northern Missouri at preplant and postplant of 1994 and 1995, and an additional 46 streams were sampled in eight midwestern states at postplant of 1995. Samples were analyzed for atrazine, deethylatrazine (DEA), deisopropylatrazine (DIA), and three HADPs. Overall, HADP prevalence (i.e., frequency of detection) ranged from 87 to 100% for hydroxyatrazine (HA), 0 to 58% for deethylhydroxyatrazine (DEHA), and 0% for deisopropylhydroxyatrazine (DIHA) with method detection limits of 0.04-0.10 ??g L-1. Atrazine metabolites accounted for nearly 60% of the atrazine load in northern Missouri streams at preplant, with HA the predominant metabolite present. Data presented in this study and a continuous monitoring study are used to support the hypothesis that a combination of desorption from stream sediments and dissolved-phase transport control HADP concentrations in streams.

  12. Occurrence and fate of alkylphenol polyethoxylate degradation products and linear alkylbenzene sulfonate surfactants in urban ground water: Barcelona case study

    NASA Astrophysics Data System (ADS)

    Tubau, Isabel; Vázquez-Suñé, Enric; Carrera, Jesús; González, Susana; Petrovic, Mira; López de Alda, María J.; Barceló, Damià

    2010-03-01

    SummaryThis study investigates the fate of alkylphenol polyethoxylates (APEOs) degradation products (DPs) and the occurrence of linear alkylbenzene sulfonate (LAS) surfactants in urban ground water at field scale. The occurrence of APEOs DPs in ground water was studied in connection with: (1) sources of recharge or/and pollution containing these substances, (2) ground water redox conditions, (3) occurrence of LAS, which are currently the domestic surfactants more used in the study area and (4) other common contaminants in urban ground water in the city of Barcelona. The APEOs DPs analyzed included two nonylphenol carboxylates (NP2EC, NP1EC), two octylphenol carboxylates (OP2EC, OP1EC), nonylphenol (NP) and octylphenol (OP). The highest groundwater concentrations of APEOs DPs were detected in aquifers whose major source of recharge is a river receiving large amounts of effluents from secondary waste water treatment plants (WWTPs). In fact, APEOs DPs concentrations were above those in the river. NP2EC was the compound detected at highest concentrations. These increase with ammonium in samples with low dissolved oxygen. These degradation products were virtually absent in oxidizing aquifers whose main source of recharge is not the river. In this case, only the ultimate degradation product (NP) was detected, which suggests that parent compounds have degraded. These results indicate that APEOs are persistent or less degraded in reducing conditions, whereas they are degraded when oxidizing conditions prevail. By contrast, LAS concentrations were more than one order of magnitude lower than expected based on recharge sources in all (oxidizing and reducing) aquifers.

  13. PEGylated single-walled carbon nanotubes activate neutrophils to increase production of hypochlorous acid, the oxidant capable of degrading nanotubes

    SciTech Connect

    Vlasova, Irina I., E-mail: irina.vlasova@yahoo.com [Research Institute for Physico-Chemical Medicine, Federal Medico-Biological Agency, Moscow (Russian Federation); Vakhrusheva, Tatyana V. [Research Institute for Physico-Chemical Medicine, Federal Medico-Biological Agency, Moscow (Russian Federation)] [Research Institute for Physico-Chemical Medicine, Federal Medico-Biological Agency, Moscow (Russian Federation); Sokolov, Alexey V.; Kostevich, Valeria A. [Research Institute for Physico-Chemical Medicine, Federal Medico-Biological Agency, Moscow (Russian Federation) [Research Institute for Physico-Chemical Medicine, Federal Medico-Biological Agency, Moscow (Russian Federation); Research Institute for Experimental Medicine, Russian Academy of Medical Science, Saint Petersburg (Russian Federation); Gusev, Alexandr A.; Gusev, Sergey A. [Research Institute for Physico-Chemical Medicine, Federal Medico-Biological Agency, Moscow (Russian Federation)] [Research Institute for Physico-Chemical Medicine, Federal Medico-Biological Agency, Moscow (Russian Federation); Melnikova, Viktoriya I. [Institute of Developmental Biology, Russian Academy of Science, Moscow (Russian Federation)] [Institute of Developmental Biology, Russian Academy of Science, Moscow (Russian Federation); Lobach, Anatolii S. [Institute of Problems of Chemical Physics, Russian Academy of Science, Chernogolovka (Russian Federation)] [Institute of Problems of Chemical Physics, Russian Academy of Science, Chernogolovka (Russian Federation)

    2012-10-01

    Perspectives for the use of carbon nanotubes in biomedical applications depend largely on their ability to degrade in the body into products that can be easily cleared out. Carboxylated single-walled carbon nanotubes (c-SWCNTs) were shown to be degraded by oxidants generated by peroxidases in the presence of hydrogen peroxide. In the present study we demonstrated that conjugation of poly(ethylene glycol) (PEG) to c-SWCNTs does not interfere with their degradation by peroxidase/H{sub 2}O{sub 2} system or by hypochlorite. Comparison of different heme-containing proteins for their ability to degrade PEG-SWCNTs has led us to conclude that the myeloperoxidase (MPO) product hypochlorous acid (HOCl) is the major oxidant that may be responsible for biodegradation of PEG-SWCNTs in vivo. MPO is secreted mainly by neutrophils upon activation. We hypothesize that SWCNTs may enhance neutrophil activation and therefore stimulate their own biodegradation due to MPO-generated HOCl. PEG-SWCNTs at concentrations similar to those commonly used in in vivo studies were found to activate isolated human neutrophils to produce HOCl. Both PEG-SWCNTs and c-SWCNTs enhanced HOCl generation from isolated neutrophils upon serum-opsonized zymosan stimulation. Both types of nanotubes were also found to activate neutrophils in whole blood samples. Intraperitoneal injection of a low dose of PEG-SWCNTs into mice induced an increase in percentage of circulating neutrophils and activation of neutrophils and macrophages in the peritoneal cavity, suggesting the evolution of an inflammatory response. Activated neutrophils can produce high local concentrations of HOCl, thereby creating the conditions favorable for degradation of the nanotubes. -- Highlights: ? Myeloperoxidase (MPO) product hypochlorous acid is able to degrade CNTs. ? PEGylated SWCNTs stimulate isolated neutrophils to produce hypochlorous acid. ? SWCNTs are capable of activating neutrophils in blood samples. ? Activation of neutrophils in blood causes an increase in plasma MPO concentration. ? Intraperitoneal injection of PEG-SWCNTs in mice induces an inflammatory response.

  14. 64 FR 63036 - Pesticide Reregistration Performance Measures and Goals

    Federal Register 2010, 2011, 2012, 2013, 2014

    1999-11-18

    ...184 REDs out of a universe of 612 cases...active ingredients subject to reregistration...The status of the universe of 6,796 pesticide products subject to product reregistration...Status of Universe of Products Subject to Product...

  15. Quantifying the impact of land degradation on crop production: the case of Senegal

    NASA Astrophysics Data System (ADS)

    Sonneveld, B. G. J. S.; Keyzer, M. A.; Ndiaye, D.

    2015-06-01

    Land degradation has been a persistent problem in Senegal for a long time and by now has become a serious impediment to long term development. In this paper, we quantify the impact of land degradation on crop yields using the results of a nation-wide land degradation assessment. For this, the study needs to address two issues. First, the land degradation assessment comprises qualitative expert judgments that have to be converted into more objective, quantitative terms. We propose a land degradation index and assess its plausibility. Second, observational data on soils, land use and rainfall do not provide sufficient information to isolate the impact of land degradation. We, therefore, design a pseudo-experiment that for sites with otherwise similar circumstances compares the yield of a site with and one without land degradation. This pairing exercise is conducted under a gradual refining of the classification of circumstances, until a more or less stable response to land degradation is obtained, In this way, we hope to have controlled sufficiently for confounding variables that will bias the estimation of the impact of land degradation on crop yields. A small number of shared characteristics reveal tendencies of "severe" land degradation levels being associated with declining yields as compared to similar sites with "low" degradation levels. However, as we zoom in at more detail some exceptions come to the fore, in particular in areas without fertilizer application. Yet, our overall conclusion is that yield reduction is associated to higher levels of land degradation, irrespective of whether fertilizer is being applied or not.

  16. Parts of a Pesticide Label Active ingredients

    E-print Network

    Isaacs, Rufus

    place. Pesticide wastes are toxic. To dispose of container, triple rinse, puncture, and dispose, and chemical proof gloves. Brand Name Type of product EPA Registration Number Signal Word Amount in package

  17. Development of fermentation process for PLA-degrading enzyme production by a new thermophilic Actinomadura sp. T16-1

    Microsoft Academic Search

    Sukhumaporn Sukkhum; Shinji Tokuyama; Vichien Kitpreechavanich

    2009-01-01

    The fermentation process for a poly (L-lactide) (PLA)-degrading enzyme production by a newly isolate of thermophilic PLA-degrading\\u000a Actinomadura sp. T16-1 was investigated. The strain produced 33.9 U\\/mL of enzyme activity after cultivation at 50°C under shaking of 150\\u000a rpm for 96 h in a medium consisting of (w\\/v) 0.05% PLA film, 0.2% gelatin, 0.4% (NH4)2SO4, 0.4% K2HPO4, 0.2 % KH2PO4,

  18. End-to-end gene fusions and their impact on the production of multifunctional biomass degrading enzymes.

    PubMed

    Rizk, Mazen; Antranikian, Garabed; Elleuche, Skander

    2012-11-01

    The reduction of fossil fuels, coupled with its increase in price, has made the search for alternative energy resources more plausible. One of the topics gaining fast interest is the utilization of lignocellulose, the main component of plants. Its primary constituents, cellulose and hemicellulose, can be degraded by a series of enzymes present in microorganisms, into simple sugars, later used for bioethanol production. Thermophilic bacteria have proven to be an interesting source of enzymes required for hydrolysis since they can withstand high and denaturing temperatures, which are usually required for processes involving biomass degradation. However, the cost associated with the whole enzymatic process is staggering. A solution for cost effective and highly active production is through the construction of multifunctional enzyme complexes harboring the function of more than one enzyme needed for the hydrolysis process. There are various strategies for the degradation of complex biomass ranging from the regulation of the enzymes involved, to cellulosomes, and proteins harboring more than one enzymatic activity. In this review, the construction of multifunctional biomass degrading enzymes through end-to-end gene fusions, and its impact on production and activity by choosing the enzymes and linkers is assessed. PMID:23058915

  19. Stability-Indicating RP-HPLC Method for Simultaneous Estimation of Enrofloxacin and Its Degradation Products in Tablet Dosage Forms

    PubMed Central

    Chakravarthy, V. Ashok; Sailaja, B. B. V.; Kumar, Avvaru Praveen

    2015-01-01

    The present work was the development of a simple, efficient, and reproducible stability-indicating reverse-phase high performance liquid chromatographic (RP-HPLC) method for simultaneous determination enrofloxacin (EFX) and its degradation products including ethylenediamine impurity, desfluoro impurity, ciprofloxacin impurity, chloro impurity, fluoroquinolonic acid impurity, and decarboxylated impurity in tablet dosage forms. The separation of EFX and its degradation products in tablets was carried out on Kromasil C-18 (250 × 4.6?mm, 5??m) column using 0.1% (v/v) TEA in 10?mM KH2PO4 (pH 2.5) buffer and methanol by linear gradient program. Flow rate was 1.0?mL?min?1 with a column temperature of 35°C and detection wavelength was carried out at 278?nm and 254?nm. The forced degradation studies were performed on EFX tablets under acidic, basic, oxidation, thermal, humidity, and photolytic conditions. The degraded products were well resolved from the main active drug and also from known impurities within 65 minutes. The method was validated in terms of specificity, linearity, LOD, LOQ, accuracy, precision, and robustness as per ICH guidelines. The results obtained from the validation experiments prove that the developed method is a stability-indicating method and suitable for routine analysis. PMID:25705547

  20. Persistence assessment of cyclohexyl- and norbornyl-derived ketones and their degradation products in different OECD screening tests.

    PubMed

    Seyfried, M; van Ginkel, C G; Boschung, A; Miffon, F; Fantini, P; Tissot, E; Baroux, L; Merle, P; Chaintreau, A

    2015-07-01

    The persistence of synthetic cyclohexyl- and norbornyl-derived ketones was assessed by using OECD 301F and 301D biodegradation tests. While cyclohexyl-derived ketones either reached or came close to the pass level (60%) after 60d, the corresponding norbornyl derivatives yielded significantly less biodegradation (<40%). By analyzing extracts at 60d, the key degradation products of four norbornyl derivatives were identified. Consistently, 2-bicyclo[2.2.1]heptane carboxylic acid was found as a principal degradation product with minor quantities of bicyclo[2.2.1]heptan-2-one and 2-bicyclo[2.2.1]heptane acetic acid. When the three degradation products were re-synthesized and tested individually for biodegradability, the former two were found to be ultimately biodegradable after 60d in OECD 301D tests, thus proving non-persistence. Similarly, 2-bicyclo[2.2.1]heptane acetic acid was found to be degraded significantly, albeit with long lag phases exceeding 60d in the case of freshwater inoculum, then ultimately reaching the pass level. On the other hand, norbornyl ketones were still only partially biodegradable in the same test. We conclude that despite the potential for ultimate biodegradation of norbornyl-derived ketones, current screening tests yield an incomplete picture of their biodegradability, particularly when applying strict OECD criteria. The appearance of long lag phases when re-testing norbornyl ketone degradation products underlines the importance of extending tests to well beyond 28 and even 60d in the case of freshwater inocula. PMID:25769113

  1. Microcolumn LC enantioseparation of chiral compounds using diol silica gel functionalized with vancomycin crystalline degradation products.

    PubMed

    Gholami, Morteza; Ghassempour, Alireza; Alizadeh, Reza; Aboul-Enein, Hassan Y

    2009-04-01

    Vancomycin crystalline degradation products (CDPs) have been introduced as one of the newest and most interesting derivatives of vancomycin for enantiomer separation of a wide variety of chiral compounds. In this attempt, a chiral stationary phase (CSP) has been prepared using diol silica gel based on vancomycin CDPs which led to a new chiral selector with new functionality of functional groups on a microcolumn LC. Different kinds of mobile phases were examined to realize the behavior of the chiral selector in separation of atropine, fluoxetine, amlodipine, mandelic acid, alanine, and phenylalanine which were separated successfully on this column. Good results were obtained by using a polar mobile phase containing water, methanol, and acid additives for separation of chiral acidic compounds and amino acid samples. Considerable results were obtained for analysis of basic compounds by using polar organic mobile phase (POP) containing methanol, acid and base additives. These results can be associated with the presence of the carboxylic acid groups present in new CSP by using a diol silica gel. PMID:19224628

  2. Toll-like receptor 8 senses degradation products of single-stranded RNA.

    PubMed

    Tanji, Hiromi; Ohto, Umeharu; Shibata, Takuma; Taoka, Masato; Yamauchi, Yoshio; Isobe, Toshiaki; Miyake, Kensuke; Shimizu, Toshiyuki

    2015-02-01

    Toll-like receptor 8 (TLR8) recognizes viral or bacterial single-stranded RNA (ssRNA) and activates innate immune systems. TLR8 is activated by uridine- and guanosine-rich ssRNA as well as by certain synthetic chemicals; however, the molecular basis for ssRNA recognition has remained unknown. In this study, to elucidate the recognition mechanism of ssRNA, we determined the crystal structures of human TLR8 in complex with ssRNA. TLR8 recognized two degradation products of ssRNA—uridine and a short oligonucleotide—at two distinct sites: uridine bound the site on the dimerization interface where small chemical ligands are recognized, whereas short oligonucleotides bound a newly identified site on the concave surface of the TLR8 horseshoe structure. Site-directed mutagenesis revealed that both binding sites were essential for activation of TLR8 by ssRNA. These results demonstrate that TLR8 is a sensor for both uridine and a short oligonucleotide derived from RNA. PMID:25599397

  3. Herbicidal Activity of Glucosinolate Degradation Products in Fermented Meadowfoam (Limnanthes alba) Seed Meal

    PubMed Central

    STEVENS, JAN F.; REED, RALPH L.; ALBER, SUSAN; PRITCHETT, LARRY; MACHADO, STEPHEN

    2009-01-01

    Meadowfoam (Limnanthes alba) is an oilseed crop grown in western Oregon. After extraction of the oil from the seeds, the remaining seed meal contains 2-4% of the glucosinolate, glucolimnanthin. We investigated the effect of fermentation of seed meal on its chemical composition and the effect of the altered composition on downy brome (Bromus tectorum) coleoptile emergence. Incubation of enzyme-inactive seed meal with enzyme-active seeds (1% by weight) resulted in complete degradation of glucolimnanthin and formation of 3-methoxybenzyl isothiocyanate in 28% yield. Fermentation in the presence of an aqueous solution of FeSO4 (10 mM) resulted in the formation of 3-methoxyphenylacetonitrile and 2-(3-methoxyphenyl)ethanethioamide, a novel natural product. The formation of the isothiocyanate, the nitrile and the thioamide, as a total, correlated with an increase of herbicidal potency of seed meal (r2 = 0.96). The results of this study open new possibilities for the refinement of glucosinolate-containing seed meals for use as bioherbicides. PMID:19170637

  4. Herbicidal activity of glucosinolate degradation products in fermented meadowfoam ( Limnanthes alba ) seed meal.

    PubMed

    Stevens, Jan F; Reed, Ralph L; Alber, Susan; Pritchett, Larry; Machado, Stephen

    2009-03-11

    Meadowfoam ( Limnanthes alba ) is an oilseed crop grown in western Oregon. After extraction of the oil from the seeds, the remaining seed meal contains 2-4% of the glucosinolate glucolimnanthin. This study investigated the effect of fermentation of seed meal on its chemical composition and the effect of the altered composition on downy brome ( Bromus tectorum ) coleoptile emergence. Incubation of enzyme-inactive seed meal with enzyme-active seeds (1% by weight) resulted in complete degradation of glucolimnanthin and formation of 3-methoxybenzyl isothiocyanate in 28% yield. Fermentation in the presence of an aqueous solution of FeSO(4) (10 mM) resulted in the formation of 3-methoxyphenylacetonitrile and 2-(3-methoxyphenyl)ethanethioamide, a novel natural product. The formation of the isothiocyanate, the nitrile, and the thioamide, as a total, correlated with an increase of herbicidal potency of the seed meal (r(2) = 0.96). The results of this study open new possibilities for the refinement of glucosinolate-containing seed meals for use as bioherbicides. PMID:19170637

  5. Mixed-mode sorption of hydroxylated atrazine degradation products to sell: A mechanism for bound residue

    USGS Publications Warehouse

    Lerch, R.N.; Thurman, E.M.; Kruger, E.L.

    1997-01-01

    This study tested the hypothesis that sorption of hydroxylated atrazine degradation products (HADPs: hydroxyatrazine, HA; deethylhydroxyatrazine, DEHA; and deisopropylhydroxyatrazine, DIHA) to soils occurs by mixed-mode binding resulting from two simultaneous mechanisms: (1) cation exchange and (2) hydrophobic interaction. The objective was to use liquid chromatography and soil extraction experiments to show that mixed-mode binding is the mechanism controlling HADP sorption to soils and is also a mechanism for bound residue. Overall, HADP binding to solid-phase extraction (SPE) sorbents occurred in the order: cation exchange >> octadecyl (C18) >> cyanopropyl. Binding to cation exchange SPE and to a high-performance liquid chromatograph octyl (C8) column showed evidence for mixed-mode binding. Comparison of soil extracted by 0.5 M KH2P04, pH 7.5, or 25% aqueous CH3CN showed that, for HA and DIHA, cation exchange was a more important binding mechanism to soils than hydrophobic interaction. Based on differences between several extractants, the extent of HADP mixed-mode binding to soil occurred in the following order: HA > DIHA > DEHA. Mixed-mode extraction recovered 42.8% of bound atrazine residues from aged soil, and 88% of this fraction was identified as HADPs. Thus, a significant portion of bound atrazine residues in soils is sorbed by the mixed-mode binding mechanisms.

  6. Natural attenuation of trichloroethene and its degradation products at a lake-shore site.

    PubMed

    An, Youn-Joo; Kampbell, Donald H; Weaver, James W; Wilson, John T; Jeong, Seung-Woo

    2004-08-01

    Subsurface contamination by trichloroethene (TCE) was detected at a Michigan National Priorities List (NPL) site in 1982. The TCE plume resulted from the disposal of spent solvent and other chemicals at an industrial facility located in the eastern shore of Lake Michigan. TCE degradation products of three dichloroethene (DCE) isomers, vinyl chloride (VC) and ethene were present. The plume was depleted of oxygen and methanogenic at certain depths. Transects of the plume were sampled by slotted auger borings the year after the TCE plume was first discovered. Water samples were also taken from lake sediments to a depth of 12 m about 100 m offshore. Later samples were taken along the shoreline of the lake with a hand-driven probe. Later in 1998 water was taken from sediments about 3-m from the shoreline. The average concentration of each chemical and net apparent base coefficient between appropriate pairs of transects between the lower site and lakeshore were calculated. Loss rates were then calculated from an analytical solution of the two-dimensional advective-dispersive-reactive transport equation. Net apparent rate coefficients and a set of coupled reaction rate equations were used to extract the apparent loss coefficients. This study showed the field evidence for natural attenuation of TCE. PMID:15182966

  7. Use of time-resolved fluorescence spectroscopy to evaluate diagnostic value of collagen degradation products.

    PubMed

    Sikora, Joanna; Cyrankiewicz, Micha?; Wybranowski, Tomasz; Ziomkowska, Blanka; O?mia?owski, Borys; Obo?ska, Ewa; Augusty?ska, Beata; Kruszewski, Stefan; Kubica, Jacek

    2015-05-01

    The concentration of collagen degradation products (CDPs) may reflect the process of left ventricular remodeling (LVR). The aim of this study was to evaluate the potential diagnostic usefulness of time-resolved fluorescence spectroscopy (TRFS) in assessment of CDPs. The preliminary experiment was designed to establish if CDPs’ characteristics might be visible by mean fluorescence lifetime (FLT) in determined conditions. The in vitro model of CDPs was prepared by conducting the hydrolysis of type III collagen. The FLT of samples was measured by the time-resolved spectrometer Life Spec II with the subnanosecond pulsed 360-nm EPLED diode. The FLTs were obtained by deconvolution analysis of the data using a multiexponential model of fluorescence decay. In order to determine the limit of traceability of CDPs, a comparison of different collagen/plasma ratio in samples was performed. The results of our study showed that the increase of added plasma to hydrolyzed collagen extended the mean FLT. Thus, the diagnosis of LVR based on measurements using TRFS is possible. However, it is important to point out the experiment was preliminary and further investigation in this field of research is crucial. PMID:25764396

  8. Simultaneous cellulose degradation and electricity production by Enterobacter cloacae in a microbial fuel cell.

    PubMed

    Rezaei, Farzaneh; Xing, Defeng; Wagner, Rachel; Regan, John M; Richard, Tom L; Logan, Bruce E

    2009-06-01

    Electricity can be directly generated by bacteria in microbial fuel cells (MFCs) from many different biodegradable substrates. When cellulose is used as the substrate, electricity generation requires a microbial community with both cellulolytic and exoelectrogenic activities. Cellulose degradation with electricity production by a pure culture has not been previously demonstrated without addition of an exogenous mediator. Using a specially designed U-tube MFC, we enriched a consortium of exoelectrogenic bacteria capable of using cellulose as the sole electron donor. After 19 dilution-to-extinction serial transfers of the consortium, 16S rRNA gene-based community analysis using denaturing gradient gel electrophoresis and band sequencing revealed that the dominant bacterium was Enterobacter cloacae. An isolate designated E. cloacae FR from the enrichment was found to be 100% identical to E. cloacae ATCC 13047(T) based on a partial 16S rRNA sequence. In polarization tests using the U-tube MFC and cellulose as a substrate, strain FR produced 4.9 +/- 0.01 mW/m(2), compared to 5.4 +/- 0.3 mW/m(2) for strain ATCC 13047(T). These results demonstrate for the first time that it is possible to generate electricity from cellulose using a single bacterial strain without exogenous mediators. PMID:19346362

  9. Sonochemical degradation of perchloroethylene: The influence of ultrasonic variables, and the identification of products

    Microsoft Academic Search

    V. Sáez; M. D. Esclapez; P. Bonete; D. J. Walton; A. Rehorek; O. Louisnard; J. González-García

    2011-01-01

    Sonochemistry is a technique that offers promise for pollutant degradation, but earlier studies on various chlorinated substrates do not give a definitive view of the effectiveness of this methodology. We now report a thorough study of ultrasonic operational variables upon perchloroethylene (PCE) degradation in water (variables include ultrasonic frequency, power and system geometry as well as substrate concentration) and we

  10. The slow recovery of San Francisco Bay from the legacy of organochlorine pesticides.

    PubMed

    Connor, Michael S; Davis, Jay A; Leatherbarrow, Jon; Greenfield, Ben K; Gunther, Andrew; Hardin, Dane; Mumley, Thomas; Oram, John J; Werme, Christine

    2007-09-01

    The use of organochlorine pesticides, including DDTs, chlordanes, and dieldrin, peaked in San Francisco Bay's watershed 30-40 years ago, yet residues of the pesticides remain high. Known as legacy pesticides for their persistence in the Bay decades after their uses ended, the compounds and their breakdown products occur at concentrations high enough to contribute to advisories against the consumption of sport fish from the Bay. Combined with other data sets, the long-term monitoring data collected by the San Francisco Estuary Regional Monitoring Program (RMP) for trace substances allow us to track recovery of the Bay from these inputs and predict its future improvement. Legacy pesticides enter the water and sediment of San Francisco Bay from a variety of sources, including runoff from California's Central Valley and local watersheds, municipal and industrial wastewater, atmospheric deposition, erosion of historically contaminated sediment deposits, and dredging and disposal of dredged material. Runoff from small-urbanized tributaries may contribute as much or more to the loads than runoff from the agricultural Central Valley, even though 90 percent of the freshwater flow comes from the Central Valley via the Sacramento and San Joaquin rivers. The fates of legacy pesticides in San Francisco Bay are controlled by their chemical properties, including their solubilities and partition coefficients. Degradation in the sediments, outflow through the Golden Gate, and volatilization-in that relative order-result in removal of pesticides from the Bay. A contaminant fate model was used to estimate recovery times of the Bay under various scenarios. For example, under a scenario in which no new legacy pesticides entered the Bay, model predictions suggested that concentrations of pesticides in the water and the active sediment layer would reach risk-reduction goals within one to three decades. Under scenarios of continued inputs to the Bay, recovery time would be considerably longer or not reached at all. Long-term tissue monitoring corroborates model predictions of slow declines in DDT and chlordane concentrations. Field-transplanted bivalve samples indicate declines since 1980, and lipid-weight concentrations of pesticides have declined in fishes, but the declines are slow. The critical management question for the Bay is whether there are feasible management actions that would decrease concentrations in sport fish significantly faster than the existing slow progress that has been observed. PMID:16930588

  11. Modeling water infiltration and pesticides transport in unsaturated zone of a sedimentary aquifer

    NASA Astrophysics Data System (ADS)

    Sidoli, Pauline; Angulo-Jaramillo, Rafael; Baran, Nicole; Lassabatère, Laurent

    2015-04-01

    Groundwater quality monitoring has become an important environmental, economic and community issue since increasing needs drinking water at the same time with high anthropic pressure on aquifers. Leaching of various contaminants as pesticide into the groundwater is closely bound to water infiltration in the unsaturated zone which whom solute transport can occur. Knowledge's about mechanisms involved in the transfer of pesticides in the deep unsaturated zone are lacking today. This study aims to evaluate and to model leaching of pesticides and metabolites in the unsaturated zone, very heterogeneous, of a fluvio-glacial aquifer, in the South-East of France, where contamination of groundwater resources by pesticides is frequently observed as a consequence of intensive agricultural activities. Water flow and pesticide transport were evaluated from column tests under unsaturated conditions and from adsorption batch experiments onto the predominant lithofacies collected, composed of a mixture of sand and gravel. A maize herbicide, S-metolachlor, applied on the study site and worldwide and its two major degradation products (metolachlor ethanesulfonic acid and metolachlor oxanilic acid) were studied here. A conservative tracer, bromide ion, was used to determine water dispersive parameters of porous media. Elution curves were obtained from pesticide concentrations analyzed by an ultra-performance liquid chromatography system interfaced to a triple quadrupole mass spectrometer and from bromide concentrations measured by ionic chromatography system. Experimental data were implemented into Hydrus to model flow and solute transfer through a 1D profile in the vadose zone. Nonequilibrium solute transport model based on dual-porosity model with mobile and immobile water is fitting correctly elution curves. Water dispersive parameters show flow pattern realized in the mobile phase. Exchanges between mobile and immobile water are very limited. Because of low adsorptions onto fluvio-glacial deposits, retention of S-metolachlor and its ionic metabolites is low in column tests and high mobility was observed meaning these molecules are prone to reach groundwater.

  12. Hydrogeologic setting and simulation of pesticide fate and transport in the unsaturated zone of a regolith-mantled, carbonate-rock terrain near Newville, Pennsylvania

    USGS Publications Warehouse

    Hippe, D.J.; Hall, D.W.

    1996-01-01

    Physical and chemical data were collected from May 1991 through April 1993 at a 4.5 hectare field site in Cumberland County, Pa., about 5 kilometers southeast of Newville. These data were used to define the hydrogeologic setting of a field site representative of the intensively farmed carbonate valleys of southeastern and south-central Pennsylvania. The environmental processing of commonly used pesticides (herbicides, fungicides, and insecticides) in the unsaturated zone was simulated with a process- oriented digital model to evaluate the environmental fate and transport of pesticides to ground water. Site data and modelling results provide a basis for a discussion of water-quality implications of agricultural best-management practices. The carbonate valleys of Pennsylvania comprise regolith-mantled carbonate-rock terrains that consist of broad undulating upland areas dissected by mostly dry valleys and widely spaced spring-fed creeks. The upland areas are farmed and exhibit possess a doline karst topography with many closed depressions, sinkholes, and bedrock outcrops. Unsaturated materials at the field site consist of an almost continuous soil cover composed of fine-grained residuum underlain by an intermediate vadose zone composed of karstified limestone. Soils are absent on scattered bedrock outcrops and are more than 12 meters thick in other areas of the site. The soil profile stores appreciable quantities of water with a volumetric average of about 36 percent water at field capacity. Organic carbon content of soil materials is about 1.7 percent in the Ap-horizon and from 0.1 to 0.3 percent throughout the full thickness of the B- and C-horizons. Atrazine, metolachlor, simazine, and the atrazine soil metabolites deethylatrazine and deisopropylatrazine were detected at concentrations above 0.05 mg/L in just the upper 0.6 meters of soil materials. However, detectable concentrations of atrazine, simazine, and atrazine soil metabolites were measured in water samples from lysimeters installed in soil materials at depths of 1.2, 2.1, and 3.7 meters and from monitor wells completed in the saturated zone to depths of 122 meters. Data collected from the field site were used to configure a pesticide screening model based on the pesticide version of the leaching estimation and chemistry model (LEACHP) developed by Wagenet and Hutson (1987). Model simulations show that most field-applied pesticides volatilize to the atmosphere, accumulate in soils, degrade in the subsurface environment, or leach to ground water. Model results were used to rank the leaching potentials of 66 pesticides. Eighteen of 32 herbicides, 4 of 9 fungicides, and 10 of 25 insecticides have moderate to large potential for leaching to ground water. A review of available pesticide monitoring data suggests that many compounds given moderate or high leaching potentials have not been tested for in ground water and the presence of pesticides in Pennsylvania's ground water may be underreported. Monitoring data do not exist for more than two-thirds of the pesticide compounds currently used in agricultural, carbonate areas of Pennsylvania. Knowledge of processes that govern fate and transport of pesticides is needed to facilitate development of effective pesticide best-management practices. In addition to comprehensive monitoring for pesticides and pesticide degradation products in ground water downgradient of areas of pesticide use, improved (1) characterization of unsaturated flow and transport through regolith mantled carbonate rocks, (2) estimates of pesticide degradation rates, (3) understanding of soil-property controls on pesticide movement, and (4) management models developed from process-oriented research would aid in understanding the processes.

  13. Relations between Land Use and Organochlorine Pesticides, PCBs, and Semi-Volatile Organic Compounds in Streambed Sediment and Fish on the Island of Oahu, Hawaii

    USGS Publications Warehouse

    Brasher, A.M.D.; Wolff, R.H.

    2004-01-01

    Bed-sediment and/or fish samples were collected from 27 sites around the island of Oahu (representing urban, agricultural, mixed, and forested land use) to determine the occurrence and distribution of hydrophobic organic compounds including organochlorine pesticides, polychlorinated biphenyls (PCBs), and semi-volatile organic compounds (SVOCs). Of the 28 organochlorine compounds analyzed in the fish, 14 were detected during this study. Nineteen of the 31 organochlorine compounds and 40 of the 65 SVOCs were detected in the sediment. Urban sites had the highest number of detections and tended to have the highest concentrations of pesticides. Chlordane compounds were the most frequently detected constituents at urban sites, followed by dieldrin, polycyclic aromatic hydrocarbons (PAHs), and DDT compounds. PAHs were the most frequently detected constituents in watersheds with mixed (urban and agricultural) land use. The only pesticides detected at agricultural sites were DDT and its degradation products, DDD and DDE. No pesticides or PCBs were detected at the forested sites, but a few ubiquitous SVOCs were found in sediments at some forested sites. In general, concentrations of the most frequently detected pesticides were higher in fish than in sediment. Following a trend that has been observed elsewhere in the nation, concentrations of most organochlorine pesticides and PCBs are decreasing in Hawaii.

  14. Potential for bioremediation of agro-industrial effluents with high loads of pesticides by selected fungi.

    PubMed

    Karas, Panagiotis A; Perruchon, Chiara; Exarhou, Katerina; Ehaliotis, Constantinos; Karpouzas, Dimitrios G

    2011-02-01

    Wastewaters from the fruit packaging industry contain a high pesticide load and require treatment before their environmental discharge. We provide first evidence for the potential bioremediation of these wastewaters. Three white rot fungi (WRF) (Phanerochaete chrysosporium, Trametes versicolor, Pleurotus ostreatus) and an Aspergillus niger strain were tested in straw extract medium (StEM) and soil extract medium (SEM) for degrading the pesticides thiabendazole (TBZ), imazalil (IMZ), thiophanate methyl (TM), ortho-phenylphenol (OPP), diphenylamine (DPA) and chlorpyrifos (CHL). Peroxidase (LiP, MnP) and laccase (Lac) activity was also determined to investigate their involvement in pesticide degradation. T. versicolor and P. ostreatus were the most efficient degraders and degraded all pesticides (10 mg l?¹) except TBZ, with maximum efficiency in StEM. The phenolic pesticides OPP and DPA were rapidly degraded by these two fungi with a concurrent increase in MnP and Lac activity. In contrast, these enzymes were not associated with the degradation of CHL, IMZ and TM implying the involvement of other enzymes. T. versicolor degraded spillage-level pesticide concentrations (50 mg l?¹) either fully (DPA, OPP) or partially (TBZ, IMZ). The fungus was also able to rapidly degrade a mixture of TM/DPA (50 mg l?¹), whereas it failed to degrade IMZ and TBZ when supplied in a mixture with OPP. Overall, T. versicolor and P. ostreatus showed great potential for the bioremediation of wastewaters from the fruit packaging industry. However, degradation of TBZ should be also achieved before further scaling up. PMID:20635121

  15. End-to-end gene fusions and their impact on the production of multifunctional biomass degrading enzymes

    SciTech Connect

    Rizk, Mazen, E-mail: mazen.rizk@tuhh.de [Institute of Technical Microbiology, Hamburg University of Technology (TUHH), Kasernenstr. 12, D-21073 Hamburg (Germany)] [Institute of Technical Microbiology, Hamburg University of Technology (TUHH), Kasernenstr. 12, D-21073 Hamburg (Germany); Antranikian, Garabed, E-mail: antranikian@tuhh.de [Institute of Technical Microbiology, Hamburg University of Technology (TUHH), Kasernenstr. 12, D-21073 Hamburg (Germany)] [Institute of Technical Microbiology, Hamburg University of Technology (TUHH), Kasernenstr. 12, D-21073 Hamburg (Germany); Elleuche, Skander, E-mail: skander.elleuche@tuhh.de [Institute of Technical Microbiology, Hamburg University of Technology (TUHH), Kasernenstr. 12, D-21073 Hamburg (Germany)] [Institute of Technical Microbiology, Hamburg University of Technology (TUHH), Kasernenstr. 12, D-21073 Hamburg (Germany)

    2012-11-09

    Highlights: Black-Right-Pointing-Pointer Multifunctional enzymes offer an interesting approach for biomass degradation. Black-Right-Pointing-Pointer Size and conformation of separate constructs play a role in the effectiveness of chimeras. Black-Right-Pointing-Pointer A connecting linker allows for maximal flexibility and increased thermostability. Black-Right-Pointing-Pointer Genes with functional similarities are the best choice for fusion candidates. -- Abstract: The reduction of fossil fuels, coupled with its increase in price, has made the search for alternative energy resources more plausible. One of the topics gaining fast interest is the utilization of lignocellulose, the main component of plants. Its primary constituents, cellulose and hemicellulose, can be degraded by a series of enzymes present in microorganisms, into simple sugars, later used for bioethanol production. Thermophilic bacteria have proven to be an interesting source of enzymes required for hydrolysis since they can withstand high and denaturing temperatures, which are usually required for processes involving biomass degradation. However, the cost associated with the whole enzymatic process is staggering. A solution for cost effective and highly active production is through the construction of multifunctional enzyme complexes harboring the function of more than one enzyme needed for the hydrolysis process. There are various strategies for the degradation of complex biomass ranging from the regulation of the enzymes involved, to cellulosomes, and proteins harboring more than one enzymatic activity. In this review, the construction of multifunctional biomass degrading enzymes through end-to-end gene fusions, and its impact on production and activity by choosing the enzymes and linkers is assessed.

  16. New Carbon Source From Microbial Degradation of Pre-Production Resin Pellets from the North Pacific Gyre

    NASA Astrophysics Data System (ADS)

    Neal, A.; Mielke, R.; Stam, C. N.; Gonsior, M.; Tsapin, A. I.; Lee, G.; Leftwich, B.; Narayan, R.; Coleman, H.; Argyropoulos, N.; Sheavly, S. B.; Gorby, Y. A.

    2011-12-01

    Numerous pollutants are transported through the world's oceans that impact oceanic health. Diffuse sources include land-based runoff, atmospheric depositions, shipping industry wastes, and others. Synthetic polymer marine debris is a multi-faceted problem that includes interactions with environmental toxins, carbon cycling systems, ocean surface chemistry, fine minerals deposition, and nano-particles. The impact that synthetic polymer-microbe interactions have on carbon input into the open ocean is poorly understood. Here we demonstrate that both biotic and abiotic processes contribute to degradation of pre-production resin pellets (PRPs), in open ocean environments and new methodologies to determine carbon loss from this synthetic polymer debris. Our data shows that material degradation of environmental polyethylene PRPs can potentially deposit 13 mg/g to 65 mg/g of carbon per PRP into our marine environments. Environmental pre-production resin pellets were collected on the S/V Kaisei cruise in 2009 which covered over 3,000 nautical miles and sampled over 102,000 m3 of the first 15cm of the water column in the Subtropical Convergence Zone of the North Pacific Gyre. Environmental PRP degradation and the role microbial communities play in this was evaluated using a combination of Fourier transform infrared spectroscopy, environmental scanning electron microscopy, scanning transmission electron microscopy, X-ray microtomography, and ArcGIS mapping. More research is needed to understand the environmental impact of this new carbon source arising from synthetic polymers as they degrade in oceanic environments.

  17. Changes in Rice Pesticide Use and Surface Water Concentrations in the Sacramento River Watershed, California

    USGS Publications Warehouse

    Orlando, James L.; Kuivila, Kathryn M.

    2004-01-01

    Pesticides applied to rice fields in California are transported into the Sacramento River watershed by the release of rice field water. Despite monitoring and mitigation programs, concentrations of two rice pesticides, molinate and thiobencarb, continue to exceed the surface-water concentration performance goals established by the Central Valley Regional Water Quality Control Board. There have been major changes in pesticide use over the past decade, and the total amount of pesticides applied remains high. Molinate use has declined by nearly half, while thiobencarb use has more than doubled; carbofuran has been eliminated and partially replaced by the pyrethroid pesticide lambda-cyhalothrin. A study was conducted in 2002 and 2003 by the U.S. Geological Survey to determine if the changes in pesticide use on rice resulted in corresponding changes in pesticide concentrations in surface waters. During the rice growing season (May-July), water samples, collected weekly at three sites in 2002 and two sites in 2003, were analyzed for pesticides using both solid-phase and liquid-liquid extraction in combination with gas chromatography/mass spectrometry. Analytes included lambda-cyhalothrin, molinate, thiobencarb, and two degradation products of molinate: 2-keto-molinate and 4-keto-molinate. Molinate, thiobencarb, and 4-keto-molinate were detected in all samples, 2-keto-molinate was detected in less than half of the samples, and lambda-cyhalothrin was not detected in any samples. At two of the sites sampled in 2002 (Colusa Basin Drain 1 and Sacramento Slough), concentrations of molinate were similar, but thiobencarb concentrations differed by a factor of five. Although concentrations cannot be estimated directly from application amounts in different watersheds, the ratio of molinate to thiobencarb concentrations can be compared with the ratio of molinate to thiobencarb use in the basins. The higher concentration ratio in the Sacramento Slough Basin, compared with the ratio in the basin area feeding the Colusa Basin Drain 1, is consistent with the higher use ratio, suggesting that differences in application amounts can explain the observed concentration differences. The samples from the downstream site (Tower) sampled in 2002 had the lowest concentrations of pesticides. Performance goals were exceeded for either molinate or thiobencarb in six samples from the upstream sites, but not in any samples from the downstream Tower site. In 2003, concentrations at upstream sites were much lower than the previous year with only one sample containing thiobencarb at a concentration above the performance goal. Lower concentrations could be partially due to delays in rice planting and pesticide application owing to spring rainstorms. Historical data is available on peak concentrations of molinate and thiobencarb measured at Colusa Basin Drain 5 (one of our sites in 2003) since 1981. Implementing holding times for pesticide-treated rice field water in the early 1980s succeeded in decreasing concentrations in surface waters. Detailed pesticide use data is available since 1991 and changing use patterns for molinate and thiobencarb can explain some, but not all, of the trends in peak pesticide concentrations. A stronger relationship is seen between the lengths of time that performance goals were exceeded and the amount of a pesticide applied within a basin. Different extraction and analytical techniques were used to improve the recovery and lower the method detection limit for lambda-cyhalothrin. Recoveries of lambda-cyhalothrin from solid-phase extraction cartridges typically vary, so subsamples were processed by liquid-liquid extraction. The advantage of using a larger sample volume (3 L instead of 1 L) to lower detection limits was offset by poor recovery during the cleanup step using an activated carbon column. Results suggest that as the concentrations of dissolved organic carbon in the sample increase, the recovery g

  18. Degradation of dioxins by cyclic ether degrading fungus, Cordyceps sinensis

    Microsoft Academic Search

    Kunichika Nakamiya; Shyunji Hashimoto; Hiroyasu Ito; John S. Edmonds; Akio Yasuhara; Masatoshi Morita

    2005-01-01

    Use of the cyclic ether degrading fungus, Cordyceps sinensis strain A to degrade dibenzo-p-dioxin (DD), 2,3,7-trichlorodibenzo-p-dioxin (2,3,7-triCDD) and octachlorodibenzo-p-dioxin (octaCDD) has revealed a new degradation pathway for dioxins. Catechols and other possible degradation products were synthesized to facilitate the identification, detection and quantification of these products, and phenylboronate was used for the derivatization and analysis of dihydroxylated degradation products. Degradation

  19. Characterization of degradation products of ivabradine by LC-HR-MS/MS: a typical case of exhibition of different degradation behaviour in HCl and H2SO4 acid hydrolysis.

    PubMed

    Patel, Prinesh N; Borkar, Roshan M; Kalariya, Pradipbhai D; Gangwal, Rahul P; Sangamwar, Abhay T; Samanthula, Gananadhamu; Ragampeta, Srinivas

    2015-02-01

    A validated stability-indicating HPLC method was established, and comprehensive stress testing of ivabradine, a cardiotonic drug, was carried out as per ICH guidelines. Ivabradine was subjected to acidic, basic and neutral hydrolysis, oxidation, photolysis and thermal stress conditions, and the resulting degradation products were investigated by LC-PDA and LC-HR-MS/MS. The drug was found to degrade in acid and base hydrolysis. An efficient and selective stability assay method was developed on Phenomenex Luna C18 (250?×?4.6?mm, 5.0?µm) column using ammonium formate (10?mM, pH?3.0) and acetonitrile as mobile phase at 30?°C in gradient elution mode. The flow rate was 0.7?ml/min and detection wavelength was 286?nm. A total of five degradation products (I-1 to I-5) were identified and characterized by LC-HR-MS/MS in combination with accurate mass measurements. The drug exhibited different degradation behaviour in HCl and H2SO4 hydrolysis conditions. It is a unique example where two of the five degradation products in HCl hydrolysis were absent in H2SO4 acid hydrolysis. The present study provides guidance to revise the stress test for the determination of inherent stability of drugs containing lactam moiety under hydrolytic conditions. Most probable mechanisms for the formation of degradation products have been proposed on the basis of a comparison of the fragmentation pattern of the drug and its degradation products. In silico toxicity revealed that the degradation products (I-2 to I-5) were found to be severe irritants in case of ocular irritancy. The analytical assay method was validated with respect to specificity, linearity, range, precision, accuracy and robustness. PMID:25800016

  20. Regulation of the production of secretory proteins: intracellular degradation of newly synthesized "defective" collagen.

    PubMed

    Berg, R A; Schwartz, M L; Crystal, R G

    1980-08-01

    Confluent cultures of human fetal lung fibroblasts degrade approximately 10% of their newly synthesized collagen within the cell prior to secretion. This basal level of intracellular degradation could not be inhibited by colchicine or cytochalasin B, inhibitors of microtubular and microfilament function, respectively, or by N(alpha)-p-tosyl-L-lysine chloromethyl ketone, chloroquine, or NH(4)Cl, inhibitors of lysosomal enzymes. In contrast, cells in early logarithmic growth degrade approximately 30% of their newly synthesized collagen. This enhanced degradation of collagen in rapidly growing cells could be suppressed by inhibitors of lysosomal proteases and partially inhibited by disrupters of microtubular and microfilament function. A significant proportion of the collagen synthesized by these cultures contained prolyl residues that were incompletely hydroxylated. Because such collagen is "defective" (i.e., not capable of assuming a triple helical conformation), the results suggest that enhanced intracellular degradation may be a mechanism by which cells control the quality of collagen they produce. To test this hypothesis, confluent cells were incubated with the proline analog cis-4-hydroxyproline; such cells demonstrated enhanced collagen degradation that could be inhibited by agents that interfere with lysosomal, microtubular, or microfilament function. Because collagen containing cis-4-hydroxyproline cannot form a perfect triple helix, the data are consistent with the concept that defective collagen is recognized by cells and degraded prior to secretion. Thus, the proportion of newly synthesized collagen that undergoes intracellular degradation seems to be modulated, in part, by the conformation of the collagen molecule. Intracellular proteolysis may represent a means by which collagen-producing cells regulate the quality and quantity of collagen available for extracellular function. Although the exact mechanism of intracellular collagen degradation is unknown, the data presented here are consistent with a role for lysosomal proteases in this process. PMID:6933520