These are representative sample records from Science.gov related to your search topic.
For comprehensive and current results, perform a real-time search at Science.gov.
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

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.

Domagalski, J.

1996-01-01

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

Photocatalytic degradation of pesticide methomyl: determination of the reaction pathway and identification of intermediate products.  

PubMed

The degradation of pesticide methomyl in aqueous solution by UV-irradiation in the presence of TiO2 "Degussa P-25" has been studied. It was found that mineralisation to carbon dioxide, water, sulfate and ammonia took place during the process. The rate of photodecomposition of methomyl was measured using high performance liquid chromatography (HPLC), while its mineralization was followed using ion chromatography (IC), and total organic carbon (TOC) analysis. The identification of reaction intermediate products was carried out using coupled techniques HPLC-MS (electrospray ionization in positive mode) and a degradation pathway was proposed. Under our conditions, complete disappearance of 1.23 x 10(-4) mol l(-1) of pure pesticide occurred within 45 min of illumination and 80% TOC removal occurred in less than 4 h. Three main intermediates were identified resulting from (i) the rupture of the ester bond (or the N-O bond), (ii) the hydroxylation of methyl group borne by the nitrogen atom and (iii) the product resulting from the decarboxylation of the oxidized hydroxylated methyl group (photo-Kolbe reaction). In order to be sure that the photocatalytic results were consistent, hydrolysis and photolysis tests were performed. Photocatalysis proved to be an excellent new advanced oxidation technology (AOT) to eliminate methomyl present in water. PMID:16685325

Tamimi, M; Qourzal, S; Assabbane, A; Chovelon, J-M; Ferronato, C; Ait-Ichou, Y

2006-05-01

6

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

NASA Astrophysics Data System (ADS)

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

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

2013-04-01

7

A Study of the Degradation of Organophosphorus Pesticides in River Waters and the Identification of Their Degradation Products by Chromatography Coupled with Mass Spectrometry  

Microsoft Academic Search

The degradation of selected organophosphorus pesticides (OPs), i.e., malathion and parathion, in river water, has been studied\\u000a with solar simulator irradiation. The degradation of OPs and formation of degradation products were determined by chromatography\\u000a coupled with mass spectrometry analysis. The effect of a photosensitizer, i.e., riboflavin, on the photolysis of OPs in a\\u000a river-water environment was examined. There was no

Xueheng Zhao; Huey-Min Hwang

2009-01-01

8

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

Microsoft Academic Search

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

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

2011-01-01

9

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...

10

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...

11

Levels and patterns of organochlorine pesticides and their degradation products in rainwater in Kibaha Coast Region, Tanzania.  

PubMed

The levels and patterns of organochlorine pesticides and degradation products in rainwater samples collected in relation to a contaminated site in Kibaha district, Tanzania were investigated. The compounds detected in the samples by GC-MS and isotope dilution methodology included DDT, DDE, DDD, HCHs, dieldrin, heptachlor, chlordane, endrin and hexachlorobenzene. The concentrations of total DDT and total HCH ranged 0.005-3200?gL(-1) and 0.01-170?gL(-1), respectively and they indicated input of significantly non-degraded technical mixtures. The highest concentrations for other compounds ranged 0.001-1.3?gL(-1). The highest concentrations were found in samples collected in the vicinity of the contaminated site and the concentrations at other points showed a general even distribution suggesting repeated volatilization and deposition mechanisms. The strong positive correlations in the concentrations of the compounds indicated a common source. A decrease in concentrations with time was indicated, although the decrease was not significant during the period of sampling. The findings indicate risks and concerns for public and environmental health. PMID:25433398

Mahugija, John Andrew Marco; Henkelmann, Bernhard; Schramm, Karl-Werner

2015-01-01

12

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

PubMed

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

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

2014-06-01

13

Disposal and degradation of pesticide waste.  

PubMed

Generation of pesticide waste is inevitable during every agricultural operation from storage to use and equipment cleanup. Large-scale pesticide manufacturers can afford sophisticated recovery, treatment, and cleanup techniques. Small-scale pesticide users, for example, single farms or small application businesses, struggle with both past waste problems, including contaminated soils, and disposal of unused product and equipment rinsewater. Many of these problems have arisen as a result of inability to properly handle spills during, equipment loading and rinsewater generated after application. Small-scale facilities also face continued problems of wastewater handling. Old, obsolete pesticide stocks are a vexing problem in numerous developing countries. Pesticide waste is characterized by high concentrations of a diversity of chemicals and associated adjuvants. Dissipation of chemicals at elevated concentrations is much slower than at lower concentrations, in part because of microbial toxicity and mass transfer limitations. High concentrations of pesticides may also move faster to lower soil depths, especially when pore water becomes saturated wish a compound. Thus, if pesticide waste is not properly disposed of, groundwater and surface water contamination become probable. The Waste Management Hierarchy developed as an Australian Code of Practice can serve as a guide for development of a sound waste management plan. In order of desirability, the course of actions include waste avoidance, waste reduction, waste recycling, waste treatment, and waste disposal. Proper management of pesticide stocks, including adequate storage conditions, good inventory practices, and regular turnover of products,. will contribute to waste avoidance and reduction over the long-term. Farmers can also choose to use registered materials that have the lowest recommended application rates or are applied in the least volume of water. Wastewater that is generated during equipment rinsing can be recycled by spraying it onto cropland, thus avoiding a soil contamination problem. If it is not feasible to spray out rinsates, then water treatment becomes necessary. However, for small waste generators, practical technology is still too experimental and not easily implemented on an individual farm or at a small application business. Nevertheless, research has been quite active in application of advanced oxidation processes (UV/ozonation: photoassisted Fenton reaction: photocatalysis using TiO2). Obsolete pesticide stocks in developing countries are being packaged and shipped to developed countries for incineration. Contaminated soil can also be incinerated, but this is not practical nor affordable for small waste generators. Chemical degradation of chlorinated hydrocarbon pesticides may be amenable to dechlorination by alkali polyethylene glycol treatment, but further study is needed to make the technique practical for small waste generators. Contaminated soils may be amenable to cleanup by one of several biological treatment methods, including composting, landfarming, and bioaugmentation/ biostimulation. Composting and landfarming (which may be used in combination with biostimulation) may be the most practical of the biological methods that is immediately ready for implementation by small-scale pesticide waste generators. PMID:12666819

Felsot, Allan S; Racke, Kenneth D; Hamilton, Denis J

2003-01-01

14

Microbial Degradation of Pesticides in Tropical Soils  

Microsoft Academic Search

\\u000a Although their use is at least as essential in tropical as in temperate zones, pesticides remain little studied as regards\\u000a their fate and microbial degradation in tropical soils. To contribute to closing this gap, this review examines to what extent\\u000a results from studies on pesticide microbial degradation in temperate zones can be extrapolated to the tropics. It is concluded\\u000a that

Ziv Arbeli; Cilia L. Fuentes

15

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...

16

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 ...

17

Microbial degradation of an organophosphate pesticide, malathion.  

PubMed

Organophosphorus pesticide, malathion, is used in public health, residential, and agricultural settings worldwide to control the pest population. It is proven that exposure to malathion produce toxic effects in humans and other mammals. Due to high toxicity, studies are going on to design effective methods for removal of malathion and its associated compounds from the environment. Among various techniques available, degradation of malathion by microbes proves to be an effective and environment friendly method. Recently, research activities in this area have shown that a diverse range of microorganisms are capable of degrading malathion. Therefore, we aimed at providing an overview of research accomplishments on this subject and discussed the toxicity of malathion and its metabolites, various microorganisms involved in its biodegradation and effect of various environmental parameters on its degradation. PMID:23442144

Singh, Baljinder; Kaur, Jagdeep; Singh, Kashmir

2014-05-01

18

ORGANOPHOSPHATE PESTICIDE DEGRADATION UNDER DRINKING WATER TREATMENT CONDITIONS: MODELING PERSPECTIVES  

EPA Science Inventory

The objectives of this work were to develop experimental approaches and a modeling philosophy to study degradation of organophosphate pesticides as a class under drinking water treatment conditions....

19

Biotic and abiotic degradation of pesticide Dufulin in soils.  

PubMed

Dufulin is a newly developed antiviral agent (or pesticide) that activates systemic acquired resistance of plants. This pesticide is widely used in China to prevent abroad viral diseases in rice, tobacco and vegetables. In this study, the potential impacts such as soil type, moisture, temperature, and other factors on Dufulin degradation in soil were investigated. Degradation of Dufulin followed the first-order kinetics. The half-life values varied from 2.27 to 150.68 days. The dissipation of Dufulin was greatly affected by soil types, with DT50 (Degradation half time) varying between 17.59, 31.36, and 43.32 days for Eutric Gleysols, Cumulic Anthrosols, and Dystric Regosols, respectively. The elevated moisture accelerated the decay of Dufulin in soil. Degradation of Dufulin increased with temperature and its half-life values ranged from 16.66 to 42.79 days. Sterilization of soils and treatment with H2O2 resulted in a 6- and 8-fold decrease in degradation rates compared to the control, suggesting that Dufulin degradation was largely governed by microbial processes. Under different light spectra, the most effective degradation occurred with 100-W UV light (DT50=2.27 days), followed by 15-W UV light (DT50=8.32 days) and xenon light (DT50=14.26 days). Analysis by liquid chromatography-mass spectroscopy (LC-MS) revealed that 2-amino-4-methylbenzothiazole was one of the major decayed products of Dufulin in soils, suggesting that elimination of diethyl phosphate and 2-fluorobenzaldehyde was most like the degradation pathway of Dufulin in Eutric Gleysols. PMID:24323324

Wang, Hua Zi; Zuo, Hai Gen; Ding, Ya Juan; Miao, Shan Shan; Jiang, Chen; Yang, Hong

2014-03-01

20

Potential Transport and Degradation of “Aged” Pesticide Residues in Soil  

Technology Transfer Automated Retrieval System (TEKTRAN)

Increased pesticide residence time in soil, or “aging”, has been shown to affect the sorption-desorption of pesticides in the soil, which in turn can control transport and degradation processes. Aging effects have been characterized by batch sequential extraction methods, in which sorption coefficie...

21

Product List: Pesticides and Household Chemicals  

E-print Network

Product List: Pesticides and Household Chemicals This document will help you identify the products you use. These are the types of products you will find pictured in this document: PESTICIDES Outdoor! Yard & Deck Area Repellent II #04D 9/6/2007 Page 1 of 17SUPERB Study Product List: PESTICIDES #12

Leistikow, Bruce N.

22

Pesticide runoff from greenhouse production.  

PubMed

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

Roseth, Roger; Haarstad, Ketil

2010-01-01

23

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

Federal Register 2010, 2011, 2012, 2013, 2014

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

2012-12-12

24

Simultaneous Degradation of Organophosphorus Pesticides and  

E-print Network

) pesticides and p-nitrophenol (PNP). The truncated ice nucleation protein (INPNC) anchor was used to target or- ganophosphorus pesticides used for agriculture crop protection (Kumar et al., 1996). Because (Cook et al., 1978). On the other hand, the toxic eect of PNP on biological systems has led to its

Chen, Wilfred

25

Illegal Pesticide Products  

MedlinePLUS

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

26

Degradation of glyphosate and other pesticides by ligninolytic enzymes  

Microsoft Academic Search

The ability of pure manganese peroxidase (MnP), laccase, lignin peroxidase (LiP) and horseradish peroxidase (HRP) to degrade\\u000a the widely used herbicide glyphosate and other pesticides was studied in separate in vitro assays with addition of different\\u000a mediators. Complete degradation of glyphosate was obtained with MnP, MnSO4 and Tween 80, with or without H2O2. In the presence of MnSO4, with or

Leticia Pizzul; María del Pilar Castillo; John Stenström

2009-01-01

27

Potential transport and degradation of “Aged” pesticide residues in soil  

Technology Transfer Automated Retrieval System (TEKTRAN)

“Aging” has been shown to affect the sorption-desorption of pesticides in the soil, which in turn can control transport and degradation processes. Aging effects have been characterized by batch sequential extraction methods, in which sorption coefficients (i.e. Kd) are determined for the chemical re...

28

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 ...

29

71 FR 19506 - Pesticide Product; Registration Approval  

Federal Register 2010, 2011, 2012, 2013, 2014

...register the pesticide products, Avachem Sorbitol Manufacturing Use Product; Avachem Sorbitol Octanoate 90.0%; LockDownretro, containing...gloeosporioides f.sp. aeschynomene, and Sorbitol Octanoate, and information on social,...

2006-04-14

30

Degradation of ethylenethiourea pesticide metabolite from water by photocatalytic processes.  

PubMed

In this study, photocatalytic (photo-Fenton and H2O2/UV) and dark Fenton processes were used to remove ethylenethiourea (ETU) from water. The experiments were conducted in a photo-reactor with an 80 W mercury vapor lamp. The mineralization of ETU was determined by total organic carbon analysis, and ETU degradation was qualitatively monitored by the reduction of UV absorbance at 232 nm. A higher mineralization efficiency was obtained by using the photo-peroxidation process (UV/H2O2). Approximately 77% of ETU was mineralized within 120 min of the reaction using [H2O2]0 = 400 mg L(-1). The photo-Fenton process mineralized 70% of the ETU with [H2O2]0 = 800 mg L(-1) and [Fe(2+)] = 400 mg L(-1), and there is evidence that hydrogen peroxide was the limiting reagent in the reaction because it was rapidly consumed. Moreover, increasing the concentration of H2O2 from 800 mg L(-1) to 1200 mg L(-1) did not enhance the degradation of ETU. Kinetics studies revealed that the pseudo-second-order model best fit the experimental conditions. The k values for the UV/H2O2 and photo-Fenton processes were determined to be 6.2 × 10(-4) mg L(-1) min(-1) and 7.7 × 10(-4) mg L(-1) min(-1), respectively. The mineralization of ETU in the absence of hydrogen peroxide has led to the conclusion that ETU transformation products are susceptible to photolysis by UV light. These are promising results for further research. The processes that were investigated can be used to remove pesticide metabolites from drinking water sources and wastewater in developing countries. PMID:24502213

Bottrel, Sue Ellen C; Amorim, Camila C; Leão, Mônica M D; Costa, Elizângela P; Lacerda, Igor A

2014-01-01

31

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

Code of Federal Regulations, 2011 CFR

...false Experimental use permit microbial pesticides product analysis data requirements table...ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS DATA REQUIREMENTS FOR PESTICIDES Microbial Pesticides § 158.2171...

2011-07-01

32

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

Code of Federal Regulations, 2010 CFR

...false Experimental use permit microbial pesticides product analysis data requirements table...ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS DATA REQUIREMENTS FOR PESTICIDES Microbial Pesticides § 158.2171...

2010-07-01

33

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 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...

2010-07-01

34

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

Code of Federal Regulations, 2011 CFR

... 2011-07-01 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...

2011-07-01

35

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

EPA Science Inventory

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

36

Pressure hydrolysis for degradation of omethoate pesticide in water  

Microsoft Academic Search

The effect of pressure on the hydrolysis rates and the degradation kinetics of environmentally persistent omethoate pesticide\\u000a was studied. The results showed that the values of k\\u000a obs increased and the values of activation volume (AV) decreased with increasing pressure. Among pH conditions (3.58, 6.01 and\\u000a 8.5), pH 8. 5 was found to be the unstable condition and its half-life

Robina Farooq; Feng-kai Lin; Yu Wang; Jian-jun Huang; Zheng Xu; S. F. Shaukat

2004-01-01

37

Pesticides  

Microsoft Academic Search

\\u000a Pesticides include plant protection and biocidal products. Many pesticides are hazardous to human health. Dermal exposure\\u000a may cause systemic toxic effects, dermatitis, or other skin effects. The use of pesticides in Europe and Northern America\\u000a is regulated for the protection of the environment and health, while severe problems are caused in developing countries. Adequate\\u000a protective equipment, working conditions, and awareness

Carola Lidén

38

Microbiological degradation of pesticides in yard waste composting.  

PubMed Central

Changes in public opinion and legislation have led to the general recognition that solid waste treatment practices must be changed. Solid-waste disposal by landfill is becoming increasingly expensive and regulated and no longer represents a long-term option in view of limited land space and environmental problems. Yard waste, a significant component of municipal solid waste, has previously not been separated from the municipal solid-waste stream. The treatment of municipal solid waste including yard waste must urgently be addressed because disposal via landfill will be prohibited by legislation. Separation of yard waste from municipal solid waste will be mandated in many localities, thus stressing the importance of scrutinizing current composting practices in treating grass clippings, leaves, and other yard residues. Yard waste poses a potential environmental health problem as a result of the widespread use of pesticides in lawn and tree care and the persistence of the residues of these chemicals in plant tissue. Yard waste containing pesticides may present a problem due to the recalcitrant and toxic nature of the pesticide molecules. Current composting processes are based on various modifications of either window systems or in-vessel systems. Both types of processes are ultimately dependent on microbial bioconversions of organic material to innocuous end products. The critical stage of the composting process is the thermophilic phase. The fate and mechanism of removal of pesticides in composting processes is largely unknown and in need of comprehensive analysis. PMID:1886519

Fogarty, A M; Tuovinen, O H

1991-01-01

39

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

PubMed Central

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

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

2015-01-01

40

Photocatalytic degradation of organophosphate and phosphonoglycine pesticides using TiO 2 immobilized on silica gel  

Microsoft Academic Search

The photocatalytic degradation of the three pesticides acephate, dimethoate, and glyphosate in water has been investigated using UV light and TiO2 immobilized on silica gel as photocatalyst. Results show that the pesticides can be efficiently degraded by the UV\\/TiO2 system used in the study. Complete (100%) decomposition of dimethoate and glyphosate was attained within 60min of irradiation, while total degradation

Glory Rose Mangat Echavia; Fumiko Matzusawa; Nobuaki Negishi

2009-01-01

41

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

Code of Federal Regulations, 2014 CFR

...biochemical pesticides product chemistry data requirements table. 158.2081 Section...AGENCY (CONTINUED) PESTICIDE PROGRAMS DATA REQUIREMENTS FOR PESTICIDES Biochemical...biochemical pesticides product chemistry data requirements table. (a)...

2014-07-01

42

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

Code of Federal Regulations, 2011 CFR

...Biochemical pesticides product chemistry data requirements table. 158.2030 Section...AGENCY (CONTINUED) PESTICIDE PROGRAMS DATA REQUIREMENTS FOR PESTICIDES Biochemical...Biochemical pesticides product chemistry data requirements table. (a)...

2011-07-01

43

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

Code of Federal Regulations, 2014 CFR

...Biochemical pesticides product chemistry data requirements table. 158.2030 Section...AGENCY (CONTINUED) PESTICIDE PROGRAMS DATA REQUIREMENTS FOR PESTICIDES Biochemical...Biochemical pesticides product chemistry data requirements table. (a)...

2014-07-01

44

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

Code of Federal Regulations, 2012 CFR

...Biochemical pesticides product chemistry data requirements table. 158.2030 Section...AGENCY (CONTINUED) PESTICIDE PROGRAMS DATA REQUIREMENTS FOR PESTICIDES Biochemical...Biochemical pesticides product chemistry data requirements table. (a)...

2012-07-01

45

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

Code of Federal Regulations, 2011 CFR

...biochemical pesticides product chemistry data requirements table. 158.2081 Section...AGENCY (CONTINUED) PESTICIDE PROGRAMS DATA REQUIREMENTS FOR PESTICIDES Biochemical...biochemical pesticides product chemistry data requirements table. (a)...

2011-07-01

46

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

Code of Federal Regulations, 2012 CFR

...biochemical pesticides product chemistry data requirements table. 158.2081 Section...AGENCY (CONTINUED) PESTICIDE PROGRAMS DATA REQUIREMENTS FOR PESTICIDES Biochemical...biochemical pesticides product chemistry data requirements table. (a)...

2012-07-01

47

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

Code of Federal Regulations, 2013 CFR

...Biochemical pesticides product chemistry data requirements table. 158.2030 Section...AGENCY (CONTINUED) PESTICIDE PROGRAMS DATA REQUIREMENTS FOR PESTICIDES Biochemical...Biochemical pesticides product chemistry data requirements table. (a)...

2013-07-01

48

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

Code of Federal Regulations, 2013 CFR

...biochemical pesticides product chemistry data requirements table. 158.2081 Section...AGENCY (CONTINUED) PESTICIDE PROGRAMS DATA REQUIREMENTS FOR PESTICIDES Biochemical...biochemical pesticides product chemistry data requirements table. (a)...

2013-07-01

49

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...

50

Degradation Rates of Six Pesticides in Water from the Sacramento River, California  

Microsoft Academic Search

The degradation rates of six pesticides were measured in water samples collected from the Sacramento River, California, in April and August 1996. Samples were spiked with the pesticides carbaryl, malathion, atrazine, simazine, methidathion, and diazinon, and the concentrations were measured at various intervals. The laboratory experiments were done in the dark in incubators at 10 ° C or 25 °

Keith Starner; Kathryn M. Kuivila; Bryan Jennings; G. Edward Moon

51

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...

52

Degradation of selected organophosphate pesticides in wastewater by dielectric barrier discharge plasma.  

PubMed

In this paper, degradation of selected organophosphate pesticides (dichlorvos and dimethoate) in wastewater by dielectric barrier discharge plasma (DBD) was studied. DBD parameters, i.e. discharge powers and air-gap distances, differently affect their degradation efficiency. The results show that better degradation efficiency is obtained with a higher discharge power and a shorter air-gap distance. The effect of radical intervention degradation was also investigated by adding radical scavenger (tert-butyl alcohol) to the pesticide solution during the experiments. The result shows that the degradation efficiency is restrained in the presence of radical scavenger. It clearly demonstrates that hydroxyl radicals are most likely the main driver for degradation process. Moreover, the kinetics indicate that the disappearance rate of pesticides follows the first-order rate law when the initial concentration of the solution is low, but shifts to zero-order at a higher initial concentration. PMID:23835613

Hu, Yingmei; Bai, Yanhong; Yu, Hu; Zhang, Chunhong; Chen, Jierong

2013-09-01

53

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

EPA Science Inventory

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

54

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

Code of Federal Regulations, 2011 CFR

...2011-07-01 2011-07-01 false Microbial pesticides product analysis data requirements table...ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS DATA REQUIREMENTS FOR PESTICIDES Microbial Pesticides § 158.2120...

2011-07-01

55

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

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Microbial pesticides product analysis data requirements table...ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS DATA REQUIREMENTS FOR PESTICIDES Microbial Pesticides § 158.2120...

2010-07-01

56

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

Code of Federal Regulations, 2010 CFR

...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...

2010-01-01

57

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

Code of Federal Regulations, 2011 CFR

...2011-01-01 2011-01-01 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...

2011-01-01

58

Effects of halving pesticide use on wheat production  

PubMed Central

Pesticides pose serious threats to both human health and the environment. In Europe, farmers are encouraged to reduce their use, and in France a recent environmental policy fixed a target of halving the pesticide use by 2018. Organic and integrated cropping systems have been proposed as possible solutions for reducing pesticide use, but the effect of reducing pesticide use on crop yield remains unclear. Here we use a set of cropping system experiments to quantify the yield losses resulting from a reduction of pesticide use for winter wheat in France. Our estimated yield losses resulting from a 50% reduction in pesticide use ranged from 5 to 13% of the yield obtained with the current pesticide use. At the scale of the whole country, these losses would decrease the French wheat production by about 2 to 3 millions of tons, which represent about 15% of the French wheat export. PMID:24651597

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

2014-01-01

59

Photocatalytic degradation of organophosphate and phosphonoglycine pesticides using TiO2 immobilized on silica gel.  

PubMed

The photocatalytic degradation of the three pesticides acephate, dimethoate, and glyphosate in water has been investigated using UV light and TiO2 immobilized on silica gel as photocatalyst. Results show that the pesticides can be efficiently degraded by the UV/TiO2 system used in the study. Complete (100%) decomposition of dimethoate and glyphosate was attained within 60 min of irradiation, while total degradation of acephate occurred after 105 min of photocatalytic treatment. Acephate and dimethoate decomposition followed the Langmuir-Hinshelwood apparent first-order degradation kinetics, suggesting the photocatalytic nature of pesticide disappearance, whereas glyphosate decomposition was governed by both adsorption and photocatalytic reactions. Evolution of heteroatoms at their highest oxidized states such as SO(4)(2-), NO(3)(-), and PO(4)(3-) ions provides evidence that pesticide degradation occurred primarily through photocatalytic oxidation reactions. Non-detection of toxic intermediates such as methamidophos and omethoate that have been reported in other studies demonstrates rapid destruction of the pesticides into harmless byproducts using the system. PMID:19481779

Echavia, Glory Rose Mangat; Matzusawa, Fumiko; Negishi, Nobuaki

2009-07-01

60

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

PubMed

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

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

2014-04-30

61

Electrically driven microseparation methods for pesticides and metabolites: IV. Effects of the nature of fluorescent labels on the enantioseparation of pesticides and their degradation products by capillary zone electrophoresis with UV and laser-induced fluorescence detection.  

PubMed

Three different fluorescent tags, namely 5-aminonaphthalene-1-sulfonic acid (ANSA), 7-aminonaphthalene-1,3-disulfonic acid (ANDSA), and 8-aminonaphthalene-1,3,6-trisulfonic acid (ANTS) were evaluated in the precolumn derivatization of some chiral phenoxy acid herbicides, some chiral transformation products of pyrethroid insecticides, and in their subsequent enantiomeric separation by capillary electrophoresis (CE). The electrolyte systems consisted of sodium phosphate buffers containing chiral surfactants such as octylglucoside (OG) or octylmaltoside (OM) at concentrations above the critical micellar concentration (CMC). Among the three different tags investigated, the ANDSA derivatives of the various solutes were more readily enantioseparated than the ANSA and ANTS derivatives. While the tagging with ANSA allowed the enantioseparation of a limited number of the chiral solute-ANSA derivatives investigated, the ANTS derivatization yielded derivatives that could not be enantioseparated. The polarity of the three different tags increases by increasing the number of sulfonic acid groups in the molecule in the following order: ANSA (one sulfonic acid) < ANDSA (two sulfonic acid groups) < ANTS (three sulfonic acid groups). This seems to indicate that the intermediate polarity of the ANDSA tag allowed more equitable nonpolar/polar interactions of the ANDSA-derivatized solutes with the OG or OM micelles, and consequently the enantioseparation of the solute-ANDSA derivatives. Thus, there is a solute polarity window for enantioresolution with alkylglycoside micelle by CE. Solutes of intermediate polarity that undergo more equitable nonpolar/polar interactions with the micelles exhibited chiral separations. PMID:10879964

Karcher, A; El Rassi, Z

2000-06-01

62

Degradation of pesticide mixture on modified matrix of a biopurification system with alternatives lignocellulosic wastes.  

PubMed

The biobed systems were designed to retain and to degrade pesticides through the properties of a biomixture composed of straw (ST), topsoil and peat (PT) 2:1:1 v/v. The ST is the main substrate in the biomixture, as it allows the proliferation of fungi that promotes pesticide degradation. The use of readily available components in the biomixture is an important aspect to build a biobed. Therefore, potential use of readily available wastes as barley husk (BH), sawdust (SW) and oat husk (OH), as total or partial substitutes of ST were tested in pesticide degradation studies. Metabolite formation and the biological activities were also evaluated. Biomixture composed of OH was highly efficient in pesticide degradation, with t½ values of 28.6, 58.9 and 26.8 d for atrazine (ATZ), chlorpyrifos (CHL) and isoproturon (ISP). On the other hand, comparable for degrading capacities with the ST based biomixture were obtained with SW and BH, but only as partial replacement. Contrarily, high t½ values (more than 100 d) were obtained in biomixtures with total substitution of ST by SW or BH. Metabolite formation was observed in all biomixtures tested, but without clear formation patterns. Moreover, high and stable biological activity was observed in the biomixtures composed of OH. Therefore, our results demonstrated that ST can be partial or totally replaced by OH in the biomixture allowing an efficient degradation of pesticide mixture. However, it is recommended that ST can be only partially replaced by BH and SW in the biomixture to allow efficient pesticide degradation. PMID:23746365

Urrutia, C; Rubilar, O; Tortella, G R; Diez, M C

2013-08-01

63

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

Federal Register 2010, 2011, 2012, 2013, 2014

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

2013-08-28

64

77 FR 59610 - Flonicamid; Applications To Add New Food Uses on Previously Registered Pesticide Products  

Federal Register 2010, 2011, 2012, 2013, 2014

...pesticide products containing the insecticide, flonicamide, pursuant to the...section 3(c) of the Federal Insecticide, Fungicide, and Rodenticide...pesticide products containing the insecticide, flonicamid,...

2012-09-28

65

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

NASA Astrophysics Data System (ADS)

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

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

2013-04-01

66

Pesticide Productivity in Green Revolution Rice Production: A Case Study of Vietnam  

Microsoft Academic Search

Data envelopment analysis is applied to original farm-level data to investigate pesticide productivity in Vietnamese rice production. Pesticides are shown to have detrimental effects on productivity. A program aimed at reducing pesticide use is shown to be more cost-efficient in some circumstances and no less technically efficient.

Erik Lichtenberg; Khanh Linh Thi Nguyen

2001-01-01

67

78 FR 25438 - Product Cancellation Order for Certain Pesticide Registrations  

Federal Register 2010, 2011, 2012, 2013, 2014

...cancellations. Any distribution, sale, or use of the products subject to this...human health, and agricultural advocates; the...interested in the sale, distribution, or use of pesticides...registrants, of 39 products registered...

2013-05-01

68

76 FR 54230 - Product Cancellation Order for Certain Pesticide Registrations  

Federal Register 2010, 2011, 2012, 2013, 2014

...cancellations. Any distribution, sale, or use of the products subject to this...human health, and agricultural advocates; the...interested in the sale, distribution, or use of pesticides...registrants, of 60 products registered...

2011-08-31

69

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

PubMed Central

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

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

2014-01-01

70

The fate of chloroacetanilide herbicides and their degradation products in the Nzoia Basin, Kenya.  

PubMed

Alachlor, metolachlor and their respective environmentally stable aniline degradation products, 2,6-diethylaniline and 2-ethyl-6-methylaniline were analyzed in water and sediment samples from 9 sites along River Nzoia, Kenya using gas chromatography. The degradation products were detected in > 90% of the sediment and water samples, while the parent compounds occurred in < 14% of the water samples. Much higher concentrations of the pesticides and their degradation products occurred in the sediment than in the water (1.4 up to 10 800-fold), indicating an accumulation of the compounds in the sediment. The constant occurrence of the degradation products in the sediment during the study period infers a persistence of these compounds. It is hypothesized that the prevailing tropical climatic conditions favor a quick breakdown of the pesticides to their environmentally stable degradation products, thereby making the latter more important pollutants than their parent products in the study area. PMID:14627373

Osano, Odipo; Nzyuko, Daniel; Tole, Mwakio; Admiraal, Wim

2003-09-01

71

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...

72

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 ...

73

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

PubMed

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

Affam, Augustine Chioma; Chaudhuri, Malay

2013-11-30

74

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

EPA Science Inventory

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

75

Degradation of Extraction from Seaweed and Its Complex with Rare Earths for Organophosphorous Pesticides  

Microsoft Academic Search

On the basis of several experiments carried out in China, it was proved that both seaweed liquid fertilizer and rare earth (RE) could promote the growth of crops and increase their yield. The effects of extraction from seaweed and its complex with RE on the degradation of organophosphorous pesticides and the yield of vegetables were investigated. The results showed that

Wang Dongfeng; Sun Jipeng; Du Dehong; Sun Liping; Chen Zhende; Xue Changhu

2007-01-01

76

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

Code of Federal Regulations, 2011 CFR

...2011-07-01 false Registrants who distribute or sell pesticide products in refillable containers. 165.65...ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS PESTICIDE MANAGEMENT AND DISPOSAL Standards for...

2011-07-01

77

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

Code of Federal Regulations, 2011 CFR

...2011-07-01 false Registrants who distribute or sell pesticide products to refillers for repackaging. 165...ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS PESTICIDE MANAGEMENT AND DISPOSAL Standards for...

2011-07-01

78

40 CFR 152.15 - Pesticide products required to be registered.  

Code of Federal Regulations, 2011 CFR

... 24 2011-07-01 2011-07-01 false Pesticide products required to be registered. 152.15...ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS PESTICIDE REGISTRATION AND CLASSIFICATION PROCEDURES...

2011-07-01

79

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

Code of Federal Regulations, 2010 CFR

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

2010-07-01

80

40 CFR 152.15 - Pesticide products required to be registered.  

Code of Federal Regulations, 2010 CFR

... 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...

2010-07-01

81

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

Code of Federal Regulations, 2010 CFR

...2010-07-01 false Registrants who distribute or sell pesticide products to refillers for repackaging. 165...ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS PESTICIDE MANAGEMENT AND DISPOSAL Standards for...

2010-07-01

82

76 FR 4686 - Product Cancellation Order for Certain Pesticide Registrations  

Federal Register 2010, 2011, 2012, 2013, 2014

...advocates; the chemical industry; pesticide users; and...264 Piperonyl Powder for Pets. Butoxide Pyrethrins...Sergeant's Pet Care Products, Inc., 2625...Chemsico, Div of United Industries Corp., P.O. Box...

2011-01-26

83

Effect of pesticides on cellulose degradation in soil under upland and flooded conditions  

Microsoft Academic Search

The effect of pesticides on cellulose degradation in a soil was estimated by incubation experiments under upland conditions, transitional flooded conditions from aerobic to anaerobic, and fully anaerobic flooded conditions. Pesticides examined were trichlamide [(RS)-N-(1-butoxy-2,2,2-trichIoroethyl)salicyl-amide], chlorothalonil (TPN, 2,4,5,6-tetrachloro-1,3-isophthalonitrile), quin-tozene (PCNB, pentachloronitrobenzene), and hymexazol (3-hydroxy-5-meth-ylisoxazol) as fungicides, paraquat (1,1?-dimethyl-4,4?-bipyridium dichloride), thiobencarb (benthiocarb, S-p-chlorobenzyldiethyl thiocarbamate), propanil (DCPA, 3?,4?-dichloropropionanilide), and butachlor [2-chloro-2?,6?-diethyI-N-(butoxymethyl)acetoanilide] as

Arata Katayama; Shozo Kuwatsuka

1991-01-01

84

Degradation of terbuthylazine, difenoconazole and pendimethalin pesticides by selected fungi cultures.  

PubMed

Contamination of waters by xenobiotic compounds such as pesticides presents a serious environmental problem with substantial levels of pesticides now contaminating European water resources. The aim of this work was to evaluate the ability of the fungi Fusarium oxysporum, Aspergillus oryzae, Lentinula edodes, Penicillium brevicompactum and Lecanicillium saksenae, for the biodegradation of the pesticides terbuthylazine, difenoconazole and pendimethalin in batch liquid cultures. These pesticides are common soil and water contaminants and terbuthylazine is considered the most persistent triazine herbicide in surface environments. P. brevicompactum and L. saksenae were achieved by enrichment, isolation and screening of fungi capable to metabolize the pesticides studied. The isolates were obtained from two pesticide-primed materials (soil and biomixture). Despite the relatively high persistence of terbuthylazine, the results obtained in this work showed that the fungi species studied have a high capability of biotransformation of this xenobiotic, comparatively the results obtained in other similar studies. The highest removal percentage of terbuthylazine from liquid medium was achieved with A. oryzae (~80%), although the major biodegradation has been reached with P. brevicompactum. The higher ability of P. brevicompactum to metabolize terbuthylazine was presumably acquired through chronic exposure to contamination with the herbicide. L. saksenae could remove 99.5% of the available pendimethalin in batch liquid cultures. L. edodes proved to be a fungus with a high potential for biodegradation of pesticides, especially difenoconazole and pendimethalin. Furthermore, the metabolite desethyl-terbuthylazine was detected in L. edodes liquid culture medium, indicating terbuthylazine biodegradation by this fungus. The fungi strains investigated could prove to be valuable as active pesticide-degrading microorganisms, increasing the efficiency of biopurification systems containing wastewaters contaminated with the xenobiotics studied or compounds with similar intrinsic characteristics. PMID:22878100

Pinto, A P; Serrano, C; Pires, T; Mestrinho, E; Dias, L; Teixeira, D Martins; Caldeira, A T

2012-10-01

85

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

PubMed

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

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

2015-02-01

86

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

Federal Register 2010, 2011, 2012, 2013, 2014

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

2010-12-01

87

Some Factors Affecting Degradation of Organochlorine Pesticides by Bacteria1  

Microsoft Academic Search

Whole cells of Bacillus cereus, Bacillus coagulans, Bacillus subtilis, Escherichia colt and Enterobacter aerogenes in trypti- case soy broth degraded DDT into two to eight metabolites. Seven metabolites were from aerobic growth of the Bacillus. Simi- lar metabolites were from anaerobic growth of E. colt and E. aerogenes but less than four metabolites were from aerobic growth of thes~ organisms.

B. E. Langlois; J. A. Collins; K. G. Sides

1970-01-01

88

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

Microsoft Academic Search

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

Keisuke Ikehata; Mohamed Gamal El-Din

2005-01-01

89

Kinetics and mechanism of the degradation of two pesticides in aqueous solutions by ozonation  

Microsoft Academic Search

This study evaluated the reaction kinetics and degradation mechanism of the pesticides bromoxynil and trifluralin during conventional ozonation. The second-order rate constants for the direct molecular ozone and hydroxyl radical reactions with bromoxynil and trifluralin were determined using a rapid-scan stopped-flow spectrophotometry, competition kinetics, and an organic substrate monitoring method. High reactivity toward ozone and hydroxyl radicals was observed for

Pamela Chelme-Ayala; Mohamed Gamal El-Din; Daniel W. Smith

2010-01-01

90

Identification of Major Degradation Products of Ketoconazole  

PubMed Central

Analytical methods were developed for the identification of major degradation products of Ketoconazole, an antifungal agent. The stressed degradation of Ketoconazole drug substance was performed under acid, base, thermal, photo and oxidative stress conditions. The major degradation was observed under acid, base and oxidative stress conditions. The degradation study was performed on Inertsil ODS-3V, length 100 X diameter 4.6 mm, particle size 3 ?m column using gradient method. These degradants were identified by LC-MS technique. PMID:22145107

Mhaske, Rajendra A.; Sahasrabudhe, Shirish

2011-01-01

91

PESTICIDES AS AN UNKNOWN COMPONENT OF BIOLOGICAL WASTE AND ITS PRODUCTS  

Microsoft Academic Search

The aim of this study was to assess the risk connected with a pesticide input from contaminated fermentation sludge. The first step was a multi residue analysis of various components of biological waste. The analysis included 50 different pesticides and revealed high concentrations of thiabendazole, ortho-phenyl-phenol, methidathione, chlorothalonil, dodemorph and endosulfan. The degradation and distribution of these pesticides during a

K. VORKAMP; J. TAUBE; M. FÖRSTER; E. KELLNER; R. HERRMANN

92

Effect of biochar and digestate on microbial respiration and pesticide degradation  

NASA Astrophysics Data System (ADS)

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

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

2014-05-01

93

75 FR 8939 - Pesticide Products; Registration Applications  

Federal Register 2010, 2011, 2012, 2013, 2014

...EPA has received applications to register pesticide...comment on these applications. DATES: Comments...available on the Internet. If you submit...not placed on the Internet and will be publicly...North American Industrial Classification...FIFRA Registration Applications On October...

2010-02-26

94

76 FR 17645 - Pesticide Products; Registration Applications  

Federal Register 2010, 2011, 2012, 2013, 2014

...has received an application to register a pesticide...comment on this application. DATES: Comments...available on the Internet. If you submit...not placed on the Internet and will be publicly...North American Industrial Classification...Registration Applications EPA has...

2011-03-30

95

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

NASA Astrophysics Data System (ADS)

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

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

2014-05-01

96

Sonochemical degradation of organophosphorus pesticide in dilute aqueous solutions.  

PubMed

Ultrasonic irradiation was found to accelerate the rate of hydrolysis of omethoate in aqueous solution over the pH range of 2-12. Process parameters studied include pH, steady-state temperature, concentration, and the type of gases. Greater than 96% hydrolysis was observed in 30 minutes through this process and the rate of destruction increased with the help of more soluble and low thermal inert gas. So with Krypton, omethoate was found to undergo rapid destruction as compared with Argon. In the presence of ultrasound, the observed first-order rate of hydrolysis of omethoate is found to be independent of pH. The formation of transient supercritical water (SCW) appears to be an important factor in the acceleration of chemical reactions in the presence of ultrasound. A detailed chemical reaction mechanism for omethoate destruction in water was formulated. Experimental results and theoretical kinetic mechanism demonstrated that the most of the omethoate undergo destruction inside the cavitating holes. A very less effect of temperature on the degradation of omethoate within a temperature range of 20-70 degrees C proves that a small quantity of omethoate undergoes secondary destruction in the bulk liquid. PMID:14562936

Farooq, Robina; Lin, Feng-Kai; Shaukat, S F; Huang, Jian-Jun

2003-09-01

97

[Validation study on a multi-residue analysis of pesticides in agricultural products by using phosphoric acid treatment and GC-MS/MS].  

PubMed

A rapid method for multi-residue determination of pesticides in agricultural products was validated. The sample was cut into pieces and placed into a mixer cup containing half weight amount of 10% phosphoric acid in order to suppress degradation of easily degraded pesticides, represented by captan, and then homogenized. Pesticides in the phosphoric acid-treated sample were extracted with acetonitrile using a homogenizer, followed by salting out with anhydrous magnesium sulfate and sodium chloride. The extract was cleaned up on a C18 and graphite carbon black/PSA mini-cartridge column. Some pesticides gave tailing peaks, but these peaks became sharp and symmetrical when polyethylene glycol (PEG) 300 was added to the test solution. Recovery tests were performed on nine kinds of agricultural products (brown rice, soybean, spinach, cabbage, potato, orange, apple, strawberry, and Japanese pear) fortified with 170 pesticides at 0.01 and 0.1 ?g/g. Each concentration of pesticide residue was extracted from 2 samples on 5 separate days. The trueness of the method for 147-164 pesticides in each sample was 70-120% with satisfactory repeatability and within-run reproducibility. This method is expected to useful for multi-residue analysis of pesticides in agricultural products. PMID:25212821

Makabe, Yuhki; Takahashi, Hiroshi; Enomoto, Tomoko; Aikawa, Takehiko

2014-01-01

98

Original article Pesticide residues in bee products collected from  

E-print Network

Original article Pesticide residues in bee products collected from cherry trees protected during-100 Skierniewice, Pomologiczna 18, Poland b University of Agriculture, Department of Botany, 20-950 Lublin, Poland and the prevention time (time elapsed from spraying to safe bee operation on the flowers) for most preparations

Paris-Sud XI, Université de

99

Planktonic versus Biofilm Catabolic Communities: Importance of the Biofilm for Species Selection and Pesticide Degradation ?  

PubMed Central

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

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

2011-01-01

100

Pesticides  

SciTech Connect

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

Sherma, J.

1987-06-15

101

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 ...

102

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

PubMed

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

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

2013-12-01

103

75 FR 4384 - Pesticide Products; Registration Applications  

Federal Register 2010, 2011, 2012, 2013, 2014

...2 T.W. Alexander Drive, Research Triangle Park, NC 27709. Product name: Indaziflam...2 T.W. Alexander Drive, Research Triangle Park, NC 27709. Product name...2 T.W. Alexander Drive, Research Triangle Park, NC 27709. Product name:...

2010-01-27

104

75 FR 19388 - Pesticide Product; Registration Application  

Federal Register 2010, 2011, 2012, 2013, 2014

...include, but are not limited to: Crop production (NAICS code 111). Animal production (NAICS code 112). Food manufacturing...Vector PV-GMIR9) Necessary for its Production in MON 87701 Soybean (OECD Unique Identifier...

2010-04-14

105

Sorption and degradation of chlorophenols, nitrophenols and organophosphorus pesticides in the subsoil under landfills — laboratory studies  

NASA Astrophysics Data System (ADS)

Landfills and old industrial plant sites have been identified in an increasing number of cases as point sources of groundwater pollution, dissipating a wide range of industrial chemicals and pesticides. To study the fate of co-disposed chemicals in the subsoil of landfills, anaerobic soil columns loaded with anaerobic leachate from a municipal landfill were set up. The leachate was spiked with eleven compounds representing three groups of chemicals: chlorophenols, nitrophenols and organophosphates. Two subsoils were used in the study. The columns were maintained at Danish groundwater temperature (8-10°C), and were run for a period of 10 months. Analysis of the influent leachate concentrations of the spiked compounds showed that the concentrations were constant during the entire experimental period. Many of the compounds showed delayed breakthrough (compared to chloride breakthrough) in both soils, followed by a constant effluent concentration ratio of less than unity indicating that degradation was occuring. The velocities for the chloro- and nitrophenols were in the range of 10-100% of the water velocity in the two subsoils. The distribution coefficient for the specific phenol, the acidity and the pH of the soil apparently governed the retardation of the phenolic compounds. Degradation of most of the phenols was observed with half-like values of 30-150 days. The four organophosphorus pesticides, Dimethoate ®, Malathion ®, Sulfotep ® and Fenitrothion ®, showed relative velocities from < 10% to ? 100%. Malathion ® and Sulfotep ® were degraded with half-life values of 10-20 days, while Dimethoate ® was not significantly degraded in the two soil columns. Fenitrothion ® did not appear in the effluent from the columns within the experimental period of time, probably due to high retardation.

Kjeldsen, Peter; Kjølholt, Jesper; Schultz, Birgit; Christensen, Thomas H.; Tjell, Jens Christian

1990-09-01

106

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

Code of Federal Regulations, 2011 CFR

... 2011-07-01 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...

2011-07-01

107

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 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...

2010-07-01

108

Monod kinetics rather than a first-order degradation model explains atrazine fate in soil mini-columns: implications for pesticide fate modelling.  

PubMed

Pesticide transport models commonly assume first-order pesticide degradation kinetics for describing reactive transport in soil. This assumption was assessed in mini-column studies with associated batch degradation tests. Soil mini-columns were irrigated with atrazine in two intermittent steps of about 30 days separated by 161 days application of artificial rain water. Atrazine concentration in the effluent peaked to that of the influent concentration after initial break-through but sharply decreased while influx was sustained, suggesting a degradation lag phase. The same pattern was displayed in the second step but peak height and percentage of atrazine recovered in the effluent were lower. A Monod model with biomass decay was successfully calibrated to this data. The model was successfully evaluated against batch degradation data and mini-column experiments at lower flow rate. The study suggested that first-order degradation models may underestimate risk of pesticide leaching if the pesticide degradation potential needs amplification during degradation. PMID:20116148

Cheyns, K; Mertens, J; Diels, J; Smolders, E; Springael, D

2010-05-01

109

Aging of organochlorine pesticides and polychlorinated biphenyls in muck soil: volatilization, bioaccessibility, and degradation.  

PubMed

An organic rich muck soil which is highly contaminated with native organochlorine pesticide (OCs) was spiked with known amounts of (13)C-labeled OCs and nonlabeled polychlorinated biphenyls (PCBs). Spiked soils were aged under indoor, outdoor, and sterile conditions and the change in volatility, surrogate bioaccessibility, and degradation of chemicals was monitored periodically over 730 d. Volatility was measured using a fugacity meter to characterize the soil-air partition coefficient (K(SA) = C(SOIL)/C(AIR)). The fraction of bioaccessible residues was estimated by comparing recoveries of chemical with a mild extractant, hydroxylpropyl-?-cyclodextrin (HPCD) vs a harsh extractant, DCM. K(SA) of the spiked OCs in the nonsterile (Indoor, Outdoor) soils were initially lower and approached the K(SA) of native OCs over time, showing reduction of volatility upon aging. HPCD extractability of spiked OCs and PCBs were negatively correlated with K(SA), which suggests that volatility can be used as a surrogate for bioaccessibility. Degradation of endosulfans, PCB 8 and 28 was observed in the nonsterile soils, and (13)C(6)-?-HCH showed selective degradation of the (+) enantiomer. Enantiomer fractions (EF) in air and HPCD extracts were lower than in nonsterile soils, suggesting greater sequestering of the (+) enantiomer in the soil during microbial degradation. PMID:21204520

Wong, Fiona; Bidleman, Terry F

2011-02-01

110

Environmental activation of pesticides.  

PubMed

Spray drift from application sites, runoff from agricultural fields, leftover products from home use, and accidental spills have made pesticide contamination ubiquitous in the environment. As a pesticide moves through the environment, it may react through chemical and biotic processes such as hydrolysis, oxidation, or reduction, or be metabolized in microorganisms, animals, plants, and humans. Most reactions will be inactivations, forming degradation products less toxic or persistent than the parent compound. However, some reactions are activations, creating breakdown products equally or more toxic, persistent, or mobile than the parent and posing a greater threat to nontarget organisms and the environment. Examples are drawn from the major classes of pesticides including organochlorine compounds (DDT and aldrin), organophosphorus pesticides (malathion), carbamate pesticides (aldicarb), and fungicides to illustrate the various activation routes. PMID:8272979

Wolfe, M F; Seiber, J N

1993-01-01

111

75 FR 34114 - Pesticide Products; Registration Applications  

Federal Register 2010, 2011, 2012, 2013, 2014

...LP2, T.W. Alexander Dr., Research Triangle Park, NC 27709. Product name: Penflufen...LP2, T.W. Alexander Dr., Research Triangle Park, NC 27709. Product name: PEN...LP2, T.W. Alexander Dr., Research Triangle Park, NC 27709. Product name:...

2010-06-16

112

88 Worker Protection Standards Tobacco Pesticides 2008 Burley ToBacco ProducTion Guide  

E-print Network

88 Worker Protection Standards Tobacco Pesticides 2008 Burley ToBacco ProducTion Guide EPA Worker Protection Standards for Commonly Used Pesticides for Burley Tobacco 2008 Danny R. Peek, Extension Specialist that requires that you take actions to protect agricultural workers from the risk of pesticide-related illness

Liskiewicz, Maciej

113

Distinguishing the effects of habitat degradation and pesticide stress on benthic invertebrates using stressor-specific metrics.  

PubMed

Hydromorphological degradation is a well known stressor for running waters, while the effects of elevated levels of pesticides are widely ignored. Hence, distinguishing between the effects of these two stressors is an urgent task for water managers that aim at appropriate remediation measures. We used a large monitoring data set on benthic invertebrates, habitat descriptors, and physico-chemical variables to develop the SPEAR[%](habitat) metric that indicates the effects of in-stream habitat degradation. SPEAR[%](habitat) correlated significantly with the habitat degradation score (HDS; based on substratum and vegetation coverage), while it did not respond to any physico-chemical variables (r(2)=0.20). This relationship improved for streams with low modeled pesticide inputs (r(2)=0.33), and improved even further for a subset of streams dominated by soft-bottom substrata, i.e. for similar stream-types (r(2)=0.65). These relationships were confirmed for an independent dataset that was not used in the derivation of the HDS (r(2)=0.57 and r(2)=0.65, respectively). These findings show that the SPEAR[%](habitat) had a high degree of specificity for the effects of habitat degradation. Conversely, neither the commonly used EPT and ASPT metrics, nor the German Fauna Index or SPEAR[%](pesticides) showed significant relationships with HDS. These metrics instead correlated significantly with the run-off potential (RP), a proxy of pesticide contamination of streams. Similarly, RP was also the most important explanatory variable for SPEAR[%](pesticides), followed by alkalinity and the number of forested upstream stretches (r(2)=0.61). The latter are expected to alleviate pesticide effects, as indicated by higher SPEAR[%](pesticides) values. These findings show that an integrated analysis of the two stressor-specific SPEAR-metrics in combination with the metrics of general ecological degradation can help water managers to distinguish between the effects of habitat degradation and pesticide stress, two co-occurring stressors in agricultural landscapes. PMID:23291651

von der Ohe, Peter Carsten; Goedkoop, Willem

2013-02-01

114

75 FR 56105 - Pesticide Products; Registration Applications  

Federal Register 2010, 2011, 2012, 2013, 2014

...symbol: 2517-RGI, 2517-RGO. Docket number: EPA-HQ-OPP-010- 0708. Company name and address: Sergeant's Pet Care Products, Inc., 2625 South 158th Plaza, Omaha, NE 68130. Active ingredient: Bifenthrin. Proposed uses:...

2010-09-15

115

75 FR 26754 - Pesticide Products; Registration Applications  

Federal Register 2010, 2011, 2012, 2013, 2014

...352-IGL. Applicant: E.I. du Pont de Nemours and Company, Inc., 1007 Market St., Wilmington, DE 19898. Product name: DPX-LEM17 50 WDG. Active ingredients: Penthiopyrad at 50%. Proposed classification/Use: End-use/ Terrestrial...

2010-05-12

116

77 FR 38285 - Pesticide Products; Registration Applications  

Federal Register 2010, 2011, 2012, 2013, 2014

...IA 50010. Product name: Bacillus pumilus strain BU F-33 Technical...Induced Systemic Resistance with Bacillus pumilus strain BU F-33 at 95%. Proposed...Induced Systemic Resistance with Bacillus pumilus strain BU F-33 at 5%....

2012-06-27

117

76 FR 5805 - Pesticide Products; Registration Applications  

Federal Register 2010, 2011, 2012, 2013, 2014

...Microbiocide and 2-methyl-1, 2-benzisothiazolin-3- one at 25%. Proposed classification/Use: For use in formulation of emulsion products, paints, building materials, adhesives and sealants, ink, textiles, paper coating, functional chemicals,...

2011-02-02

118

76 FR 10026 - Pesticide Products; Registration Applications  

Federal Register 2010, 2011, 2012, 2013, 2014

...Philadelphia, PA 19106. Active ingredient: 2-Methyl-1, 2-benzisothiazol-3 (2H)-one. Proposed Uses: For use in ATD emulsion products, paints, building materials, adhesives and sealants, ink, textiles, paper coating, functional...

2011-02-23

119

77 FR 14362 - Pesticide Products; Registration Applications  

Federal Register 2010, 2011, 2012, 2013, 2014

...Second Street, Suite B- 107, Davis, CA 95618. Product Name: MBI-005 EP. Active ingredient: Killed, non-viable Streptomyces acidiscabies strain RL-110\\T\\. Proposed Use(s): Agricultural crop, residential home and garden, and turf...

2012-03-09

120

Effects of addition of straw, chitin and manure to new or recycled biofilters on their pesticides retention and degradation properties.  

PubMed

Pollution of surface and groundwater by pesticides is an increasing problem that needs to be addressed by the authorities as well as by the farmers themselves. Nowadays, some researchers are considering the numerous small spillages at the farm sites as a relevant entry route to be taken into account for predicting surface and groundwater pollution. In order to tackle this problem, several solutions exist for limiting the disposal of pesticide wastes into the environment. One such system is biopurification of farm wastes by biobed, biofilter or phytobac. In this study, the results of pesticides retention by biofilters under outdoor conditions are presented. The biofilters were filled with a mixture of a soil + peat constituent (25% by volume for each of them) and the rest (50%) with straw or with composted manure ot with chitin (in this later case at the rate of 5 g chitin per liter of substrate). The soil + peat constituent was made either of a material already challenged by pesticides (= recycled biofilters) or of untreated material (new biofilters). Selected pesticides (atrazine, carbofuran, chloridazon, chlortoluron, cyanazine, isoproturon and lenacil) were applied onto biofilters and the eluates were collected and analyzed. Two successive injections of pesticides into the biofilters were conducted. After the first pesticides application, the recycled biofilters made of soil + peat previously treated with pesticides had better retention and degradation rates than the new biofilters. Adding manure also improved these properties of biofilters. Columns made of unchallenged soil + peat and straw (new biofilters) were the least satisfactory: up to 25% of carbofuran were lost. Biofilters made of unchallenged soil + peat and chitin retained the least lenacil. Atrazine was the most retained by biofilters (either new or recycled) with added chitin. Cyanazine was almost absent in the percolates of all biofilters. After the second application of carbofuran and isoproturon, all biofilters improved to the point where (with the exception the new biofilters made of chitin) they retained the totality of the pesticides. PMID:12701413

Genot, P; Van Huynh, N; Debongnie, Ph; Pussemier, L

2002-01-01

121

Model-based estimation of pesticides and transformation products and their export pathways in a headwater catchment  

NASA Astrophysics Data System (ADS)

Pesticides applied onto agricultural fields are frequently found in adjacent rivers. To what extent and along which pathways they are transported is influenced by intrinsic pesticide properties such as sorption and degradation. In the environment, incomplete degradation of pesticides leads to the formation of transformation products (TPs), which may differ from the parent compounds regarding their intrinsic fate characteristics. Thus, the export processes of TPs in catchments and streams may also be different. In order to test this hypothesis, we extended a distributed hydrological model by the fate and behaviour of pesticides and transformation products and applied it to a small, well-monitored headwater catchment in Switzerland. The successful model evaluation of three pesticides and their TPs at three sampling locations in the catchment enabled us to estimate the quantity of contributing processes for pollutant export. Since all TPs were more mobile than their parent compounds (PCs), they exhibited larger fractions of export via subsurface pathways. However, besides freshly applied pesticides, subsurface export was found to be influenced by residues of former applications. Export along preferential flow pathways was less dependent on substance fate characteristics than soil matrix export, but total soil water flow to tile drains increased more due to preferential flow for stronger sorbing substances. Our results indicate that runoff generation by matrix flow to tile drains gained importance towards the end of the modelling period whereas the contributions from fast surface runoff and preferential flow decreased. Accordingly, TPs were to a large extent exported under different hydrological conditions than their PCs, due to their delayed formation and longer half-lives. Thus, not only their different intrinsic characteristics but also their delayed formation could be responsible for the fact that TPs generally took different pathways than their PCs. We suggest that these results should be considered in risk assessment for the export of agricultural chemicals to adjacent rivers and that models should be extended to include both PCs and TPs.

Gassmann, M.; Stamm, C.; Olsson, O.; Lange, J.; Kümmerer, K.; Weiler, M.

2013-12-01

122

Model-based estimation of pesticides and transformation products and their export pathways in a headwater catchment  

NASA Astrophysics Data System (ADS)

Pesticides applied onto agricultural fields are frequently found in adjacent rivers. To what extent and along which pathways they are transported is influenced by intrinsic pesticide properties such as sorption and degradation. In the environment, incomplete degradation of pesticides leads to the formation of transformation products (TPs), which may differ from the parent compounds regarding their intrinsic fate characteristics. Thus, the export processes of TPs in catchments and streams may also be different. In order to test this hypothesis, we extended a distributed hydrological model by the fate and behaviour of pesticides and transformation products and applied it to a small, well-monitored headwater catchment in Switzerland. The successful model evaluation of three pesticides and their TPs at three sampling locations in the catchment enabled us to estimate the quantity of contributing processes for pollutant export. Since all TPs were more mobile than their parent compounds (PCs), they exhibited larger fractions of export via subsurface pathways. However, besides freshly applied pesticides, subsurface export was found to be influenced by residues of former applications. Export along preferential flow pathways was less dependent on substance fate characteristics than soil matrix export, but total soil water flow to tile drains increased more due to preferential flow for stronger sorbing substances. Our results indicate that runoff generation by matrix flow to tile drains gained importance towards the end of the modelling period whereas the contributions from fast surface runoff and preferential flow decreased. Accordingly, TPs were to a large extent exported under different hydrological conditions than their PCs, due to their delayed formation and longer half-lives. Thus, not only their different intrinsic characteristics but also their delayed formation could be responsible for the fact that TPs generally took different pathways than their PCs. We suggest that these results should be considered in risk assessment for the export of agricultural chemicals to adjacent rivers and that models should be extended to include both PCs and TPs.

Gassmann, M.; Stamm, C.; Olsson, O.; Lange, J.; Kümmerer, K.; Weiler, M.

2013-07-01

123

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

PubMed

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

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

2014-10-01

124

Pesticides and Pregnancy  

MedlinePLUS

... are many household products that are also considered pesticides, such as cockroach spray, rat poison, or flea collars for pets. These products are known as indoor pesticides . How can pesticides get into my body? Pesticides ...

125

Soil degradation and prevention in greenhouse production.  

PubMed

Soil degradation has been a very serious problem for sustainable production, especially by a re-cropping of greenhouse-cultivated cucumber (Cucumis statirus L.). The aim of this research was to expound the actuality for soil degradation, at the same time, put forward some suggestion for preventing from soil degradation and maintain sustainable production in greenhouse basic on the two experiments conducted in a solar greenhouse during 2001-2008 suburb area of Yan'an, Shaanxi province in North China. The result shown that cucumber fruit productivity increased as the increasing of re-cropping years, but decreased after 5years continuously cropping. As increasing of re-cropping years, the population of fungus and bacteria increased, which was assumingly main factor of soil degradation. There was significant difference in cropping models on soil bio-characteristics and system productivity. The productivity were the highest in cropping model between cucumber and greengrocery, cucumber and cowpea (Vigna sinensis L), the second higher were in cropping model between cucumber and maize (Zea mays) for green manure, cucumber and kidney bean (Phaseolus vulgaris). That was the best way to reduce soil bacteria and epiphyte amount to follow lasting three or four months during summer season after cucumber harvest, the better method was planting cowpea or other leguminous crops. Basic on the experiment, the optimums approaches to preventive soil degradation were put forward. PMID:24701378

Liang, Y; Lin, X; Yamada, S; Inoue, M; Inosako, K

2013-01-01

126

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

PubMed

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

Thomas, Kevin A; Hand, Laurence H

2011-03-01

127

Photocatalytic degradation of monocrotophos pesticide--an endocrine disruptor by magnesium doped titania.  

PubMed

Mg-doped TiO(2) with different Mg concentrations were prepared using sol-gel method and characterized by XRD, UV-visible, XPS, SEM and FT-IR. The XRD results revealed that Mg(2+) goes into the TiO(2) lattice. SEM images of the doped and pure TiO(2) indicated that there is a smaller particle size for the doped catalyst compared to that of the pure TiO(2). UV-visible absorption spectra indicated that upon doping with Mg(2+) ion, the catalyst exhibits absorption in visible region. FT-IR and XPS spectra demonstrated that the presence of Mg(2+) ion in the TiO(2) lattice as substitutional dopant. Photocatalytic activity of doped TiO(2) has been evaluated by degradation of the monocrotophos (MCP) pesticide. The effect of solution pH, catalyst dosage and initial concentration of MCP on the photocatalytic activity of Mg-doped TiO(2) with different loadings was studied. It was observed that the rate of degradation of MCP over Mg-doped TiO(2) is better than Pure TiO(2) and Degussa P-25. PMID:21177020

Avasarala, Balaram Kiran; Tirukkovalluri, Siva Rao; Bojja, Sreedhar

2011-02-28

128

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

EPA Science Inventory

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

129

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...

130

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

E-print Network

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

Boyer, Edmond

131

Acid and base degraded products of ketorolac.  

PubMed

The stability of ketorolac tromethamine was investigated in acid (0.5M HCl) and alkaline conditions (0.5M NaOH), using the same procedure reported by Devarajan et al. [2]. The acid and base degradation products were identified by liquid chromatography-mass spectrometry (LC-MS). PMID:20133100

Salaris, Margherita; Nieddu, Maria; Rubattu, Nicola; Testa, Cecilia; Luongo, Elvira; Rimoli, Maria Grazia; Boatto, Gianpiero

2010-06-01

132

76 FR 16415 - Product Cancellation Order for Certain Pesticide Registrations  

Federal Register 2010, 2011, 2012, 2013, 2014

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

2011-03-23

133

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

USGS Publications Warehouse

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.

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

2007-01-01

134

Pesticide consumption and productivity and the potential of IPM in Bangladesh.  

PubMed

The paper analyses trends in consumption, productivity and the determinants of pesticide use in Bangladesh over a 33 year period (1977-2009), including a discussion on the scope to expand Integrated Pest Management (IPM) practices. Pesticide use grew at an alarming rate of 10.0% per year (p<0.01) although the corresponding response in yield growth of major crops has been minimal (<1.0% per year). Pesticide productivity (i.e., 'gross value added from crops at constant prices' per 'kg of active ingredients of all pesticides used') is declining steadily at a rate of -8.6% per year (p<0.01). Adoption of Green Revolution (GR) technology, crop diversification, average farm size and literacy rate are the most significant determinants of pesticide use, whereas research and development (R&D) investment depresses pesticide use. Consistent evidence of excessive pesticide use in Bangladesh was observed. Although the government has shifted focus from pesticide use to IPM, its coverage remains inadequate as only 7.4% of the total farmers are covered after 30 years of effort. Tighter pesticide regulation and its effective implementation, and expansion of IPM through public, private and non-governmental organisation (NGO) stakeholders are suggested to reduce pesticide consumption. PMID:23314122

Rahman, Sanzidur

2013-02-15

135

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

PubMed

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

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

2009-10-01

136

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

NASA Astrophysics Data System (ADS)

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

Gassmann, Matthias; Olsson, Oliver; Kümmerer, Klaus

2013-04-01

137

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

Federal Register 2010, 2011, 2012, 2013, 2014

...cancellation. Any distribution, sale, or use of the product subject to this...human health, and agricultural advocates; the...interested in the sale, distribution, or use of pesticides...registrant, of a product registered...

2010-02-24

138

Toxicity of pesticides to fish. Volume 2  

SciTech Connect

This book is the first major attempt to review comprehensively all available information on the environmental fate of pesticides and their acute and chronic effects to fish. Topics considered include toxicity of individual compounds, safe concentrations, and toxicity to different age groups; influence of environmental conditions on the toxicity of pesticides to fish; toxicity of formulations, isomers, and degradation products; joint action of pesticide mixture. Insecticide resistance in fish; poly-chlorinated biphenyls and related compounds; and environmental hazard evaluation and prediction.

Murty, A.S.

1986-01-01

139

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

NASA Astrophysics Data System (ADS)

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

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

2011-06-01

140

Study on effects of temperature, moisture and pH in degradation and degradation kinetics of aldrin, endosulfan, lindane pesticides during full-scale continuous rotary drum composting.  

PubMed

Study focused on effects of temperature, moisture and pH on degradation and degradation kinetics of aldrin, endosulfan (?), endosulfan (?) and lindane during vegetable waste composting using full-scale continuous rotary drum composter (FSCRDC). Extraction, concentration and quantification of pesticides were made from waste material at different stages by ultra-sonification, silica gel column and GC-MS analysis. Removal efficiency of aldrin, endosulfan ?, endosulfan ? and lindane was found 85.67%, 84.95%, 83.20% and 81.36% respectively due to optimum temperature, moisture, pH and enhanced microbial activity. Maximum temperature in inlet zone was found 60-65°C which is most suitable for complex microbial population. After feeding and turning in inlet zone, temperature reduced to 38°C from 60 to 65°C and regained it within 7-8h, and pH reduced to 5.3±0.2 from 7.5±0.3 in 4h and regained it in 10h. Heterotrophic bacteria Bacillus sp., Pseudomonas sp. and Lactobacillus sp. also decreased from 4.4×10(3) to 7.80×10(2)CFU g(-1) in 2 h due to gradual variation in temperature and pH. No significant temperature change was found in middle and outlet zones during feeding and turning. Degradation of pesticides was observed as first order kinetics and half-life of aldrin, endosulfan ?, endosulfan ? and lindane was reduced to 25.54, 18.43, 18.43 and 27.43 d from 1095, 60, 270 and 160 d respectively. Thus, the observations in contrast of removal and degradation kinetics of organochlorine pesticides residues in vegetable waste though full-scale rotary drum composting proved it the best suited technique. PMID:24468112

Ali, Muntjeer; Kazmi, A A; Ahmed, Naseem

2014-05-01

141

Properties and degradability of hydrothermal carbonization products.  

PubMed

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

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

2013-09-01

142

Construction of genetically engineered bacteria that degrades organophosphorus pesticide residues and can be easily detected by the fluorescence.  

PubMed

Organophosphorus compounds (OPs) are widely used in agriculture and industry and there is increased concern about their toxicological effects in the environment. Bioremediation can offer an efficient and cost-effective option for the removal of OPs. Herein, we describe the construction of a genetically engineered microorganism (GEM) that can degrade OPs and be directly detected and monitored in the environment using an enhanced green fluorescent protein (EGFP) fusion strategy. The coding regions of EGFP, a reporter protein that can fluoresce by itself, and organophosphorus hydrolase (OPH), which has a broad substrate specificity and is able to hydrolyse a number of organophosphorus pesticides, were cloned into the expression vector pET-28b. The fusion protein of EGFP-OPH was expressed in E. coli BL21 (DE3) and the protein expression reached the highest level at 11 h after isopropyl beta-D-thiogalactopyranoside induction. The fluorescence of the GEM was detected by fluorescence spectrophotometry and microscopy, and its ability to degrade OPs was determined by OPH activity assay. Those GEM that express the fusion protein (EGFP and OPH) exhibited strong fluorescence intensity and also potent hydrolase activity, which could be used to degrade organophosphorus pesticide residues in the environment and can also be directly monitored by fluorescence. PMID:24645434

Li, Qin; Wang, Pan; Chen, Rui; Li, Wei; Wu, Yi-Jun

2014-01-01

143

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

EPA Science Inventory

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

144

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

Federal Register 2010, 2011, 2012, 2013, 2014

...Stocks Existing stocks are those stocks of registered pesticide products which are currently in the United States and which were packaged, labeled, and released for shipment prior to the effective date of the cancellation action. EPA anticipates allowing...

2010-02-26

145

Determination of Vapor Pressure-Temperature Relationships of Current Use Pesticides and Transformation Products  

Technology Transfer Automated Retrieval System (TEKTRAN)

Sub-cooled liquid vapor pressures of current use organochlorine and organophosphate pesticides (chlorothalonil, chlorpyrifos methyl, diazinon, fipronil) and selected transformation products (chlorpyrifos oxon, heptachlor epoxide, oxychlordane, 3,5,6-trichloro-2-pyridinol) were determined at multiple...

146

63 FR 65203 - Babolna Bioenvironmental Centre Ltd.; Approval of a Pesticide Product Registration  

Federal Register 2010, 2011, 2012, 2013, 2014

...FRL-6038-6] Babolna Bioenvironmental Centre Ltd.; Approval of a Pesticide Product...announced that Babolna Bioenvironmental Centre Ltd., 1107 Budapest X., Szallas U...for use as a monitoring device and as a control treatment on cockroaches (EPA...

1998-11-25

147

Treatment of pesticide contaminated surface water for production of potable water by a coagulation-adsorption-nanofiltration approach  

Microsoft Academic Search

The surface water bodies have become very much susceptible to pollution by pesticides due to their increased application in agriculture. The production of potable water from pesticide contaminated lake and river water was investigated by a coagulation-adsorption-nanofiltration approach. Isoproturon (IPU) was selected as a target pesticide and spiked in distilled water and then in surface water. Coagulation was done before

Baisali Sarkar; N. Venkateswralu; R. Nageswara Rao; Chiranjib Bhattacharjee; Vijay Kale

2007-01-01

148

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

PubMed

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 of other herbicides in this study. Atrazine concentrations were significantly lower at 21 through 160 days aging time compared to day 0 concentrations. Metolachlor and pendimethalin concentrations were not significantly different over time and remained high throughout the study. Microbial respiration was suppressed in treated soils from day 21 to day 160. Soybean and canola were the most successful plant species in the germination and survival tests. Generally, with increased aging of pesticides in soil, germination time decreased. Survival time of plants increased over time for some treatments indicating possible decreased bioavailability of pesticide residues. In some cases, survival time decreased at the longer 160-day aging period, possibly indicating a change in bioavailability, perhaps as the result of formation of more bioavailable and phytotoxic metabolites. No interactive effects were noted for mixtures of pesticides compared to individually applied pesticides in terms of degradation of the parent compound or on seed germination, plant survival, or microbial respiration. PMID:10874620

Anhalt, J C; Arthur, E L; Anderson, T A; Coats, J R

2000-07-01

149

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...

150

40 CFR 165.43 - Scope of pesticide products included.  

Code of Federal Regulations, 2011 CFR

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

2011-07-01

151

40 CFR 165.63 - Scope of pesticide products included.  

Code of Federal Regulations, 2011 CFR

...deterioration caused by bacteria, viruses, fungi, protozoa, algae, or slime; and (B) In the intended use is subject to...deterioration caused by bacteria, viruses, fungi, protozoa, algae, or slime. (ii) The labeling of the pesticide...

2011-07-01

152

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

PubMed

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

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

2014-01-01

153

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

PubMed Central

A population-based, incidence case–control study was conducted among women in upstate New York to determine whether pesticide exposure is associated with an increase in risk of non-Hodgkin lymphoma (NHL) among women. The study involved 376 cases of NHL identified through the State Cancer Registry and 463 controls selected from the Medicare beneficiary files and state driver’s license records. Information about history of farm work, history of other jobs associated with pesticide exposure, use of common household pesticide products, and potential confounding variables was obtained by telephone interview. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using an unconditional logistic regression model. The risk of NHL was doubled (OR = 2.12; 95% CI, 1.21–3.71) among women who worked for at least 10 years at a farm where pesticides were reportedly used. When both farming and other types of jobs associated with pesticide exposure were combined, there was a progressive increase in risk of NHL with increasing duration of such work (p = 0.005). Overall cumulative frequency of use of household pesticide products was positively associated with risk of NHL (p = 0.004), which was most pronounced when they were applied by subjects themselves. When exposure was analyzed by type of products used, a significant association was observed for mothballs. The associations with both occupational and household pesticides were particularly elevated if exposure started in 1950–1969 and for high-grade NHL. Although the results of this case–control study suggest that exposure to pesticide products may be associated with an increased risk of NHL among women, methodologic limitations related to selection and recall bias suggest caution in inferring causation. PMID:15345339

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

2004-01-01

154

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...

155

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...

156

Biodegradation and bioremediation potential of diazinon-degrading Serratia marcescens to remove other organophosphorus pesticides from soils.  

PubMed

The ability of diazinon-degrading Serratia marcescens to remove organophosphorus pesticides (OPPs), i.e. chlorpyrifos (CP), fenitrothion (FT), and parathion (PT) was studied in a mineral salt medium (MSM) and in three soils of different characteristics. This strain was capable of using all insecticides at concentration of 50 mg/l as the only carbon source when grown in MSM, and 58.9%, 70.5%, and 82.5% of the initial dosage of CP, FT, and PT, respectively was degraded within 14 days. The biodegradation experiment showed that autochthonous microflora in all soils was characterized by a degradation potential of all tested OPPs; however, the initial lag phases for degradation of CP and FT, especially in sandy soil, were observed. During the 42-day experiment, 45.3%, 61.4% and 72.5% of the initial dose of CP, FT, and PT, respectively, was removed in sandy soil whereas the degradation of CP, FT, and PT in the same period, in sandy loam and silty soils reached 61.4%, 79.7% and 64.2%, and 68.9%, 81.0% and 63.6%, respectively. S. marcescens introduced into sterile soils showed a higher degradation potential (5-13%) for OPPs removal than those observed in non-sterile soil with naturally occurring attenuation. Inoculation of non-sterile soils with S. marcescens enhanced the disappearance rates of all insecticides, and DT50 for CP, FT, and PT was reduced by 20.7, 11.3 and 13.0 days, and 11.9, 7.0 and 8.1 days, and 9.7, 14.5 and 12.6 days in sandy, sandy loam, and silty soils, respectively, in comparison with non-sterile soils with only indigenous microflora. This ability of S. marcescens makes it a suitable strain for bioremediation of soils contaminated with OPPs. PMID:23333465

Cyco?, Mariusz; ?mijowska, Agnieszka; Wójcik, Marcin; Piotrowska-Seget, Zofia

2013-03-15

157

Vitamin C Degradation Products and Pathways in the Human Lens*  

PubMed Central

Vitamin C and its degradation products participate in chemical modifications of proteins in vivo through non-enzymatic glycation (Maillard reaction) and formation of different products called advanced glycation end products. Vitamin C levels are particularly high in selected tissues, such as lens, brain and adrenal gland, and its degradation products can inflict substantial protein damage via formation of advanced glycation end products. However, the pathways of in vivo vitamin C degradation are poorly understood. Here we have determined the levels of vitamin C oxidation and degradation products dehydroascorbic acid, 2,3-diketogulonic acid, 3-deoxythreosone, xylosone, and threosone in the human lens using o-phenylenediamine to trap both free and protein-bound adducts. In the protein-free fraction and water-soluble proteins (WSP), all five listed degradation products were identified. Dehydroascorbic acid, 2,3-diketogulonic acid, and 3-deoxythreosone were the major products in the protein-free fraction, whereas in the WSP, 3-deoxythreosone was the most abundant measured dicarbonyl. In addition, 3-deoxythreosone in WSP showed positive linear correlation with age (p < 0.05). In water-insoluble proteins, only 3-deoxythreosone and threosone were detected, whereby the level of 3-deoxythreosone was ?20 times higher than the level of threosone. The identification of 3-deoxythreosone as the major degradation product bound to human lens proteins provides in vivo evidence for the non-oxidative pathway of dehydroascorbate degradation into erythrulose as a major pathway for vitamin C degradation in vivo. PMID:21885436

Nemet, Ina; Monnier, Vincent M.

2011-01-01

158

Alginate biopolymer production by Azotobacter chroococcum from whey degradation  

Microsoft Academic Search

The potential of three Azotobacter chroococcum strains for whey degradation and alginate production were investigated. After dilution, samples were spread plated on isolation agar and Manitol agar and incubated at 30 °C for 24 h. Microorganisms were screened for their ability to whey degradation and alginate production based on colony morphology, negative and capsule staining, ability to decrease the apparent

A. Khanafari; A. Akhavan Sepahei

159

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

NASA Astrophysics Data System (ADS)

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

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

2014-05-01

160

Variation in pesticide hazard from vegetable production in Great Britain from 1991 to 2003.  

PubMed

Pesticides pose a difficult problem for policy makers as society generally seeks to reduce any adverse impacts of their use, while industry claims they are important contributors to economic success. Attempts to direct policy according to scientific findings are hampered by the multidimensionality of the potential impacts of pesticides which may affect consumers, operators, wildlife and the environment. Pesticide risk indices seek to reduce these multidimensional impacts into a single dimension and have been increasingly used to understand variation in the hazard posed by pesticides at both field and regional level. This study uses one such risk index, the environmental impact quotient (EIQ), to estimate the hazard posed by pesticide usage from 1991 to 2003 on several vegetable crops grown in the UK. Results are reported for the EIQ and for the environmental impact (EI) for brassicas, peas, beans, onions, leeks, lettuce and endives. The EIQ is a dimensionless estimate of the toxicity of a product, while the EI, which combines the EIQ with data on actual usage, estimates the overall hazard of the use of a product. The exact trends in EIQ and EI varied with crop over the period 1991-2003, but overall the EIQ decreased by 19% and the EI decreased by 34%. However, the mean EI per hectare decreased by only 3%. This suggests that some of the observed reduction in EI at the national level may be related more to decrease in crop area than changes in pesticide use and management. If these observed losses in crop area are being replaced by vegetable imports from overseas, then this raises the possibility that the UK is effectively exporting any problems related to pesticide use. The ethics of this remain unclear. PMID:16886234

Cross, Paul; Edwards-Jones, Gareth

2006-11-01

161

Pesticides and health in highland Ecuadorian potato production: assessing impacts and developing responses.  

PubMed

Pesticide use in highland Ecuador is concentrated in the high-risk, commercial production of potatoes. Small farm families experience considerable exposure and adverse health consequences. The authors describe a three-pronged strategy to reduce health impacts: 1) a community-based process of education and provision of personal protective equipment to reduce exposure; 2) farmer field schools to increase agro-ecosystem understanding and to reduce pesticide use; and 3) policy interventions to restructure incentives and to reduce availability of highly toxic insecticides. They discuss the challenges faced by each and the ongoing need for integrated interventions both to reduce adverse pesticide health impacts in the developing world and to promote sustainability of agricultural production in highland ecosystems. PMID:12358074

Cole, Donald C; Sherwood, Stephen; Crissman, Charles; Barrera, Victor; Espinosa, Patrico

2002-01-01

162

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

PubMed

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

Khuwijitjaru, Pramote; Suaylam, Boonyanuch; Adachi, Shuji

2014-02-26

163

Pesticide leaching through sandy and loamy fields - Long-term lessons learnt from the Danish Pesticide Leaching Assessment Programme.  

PubMed

The European Union authorization procedure for pesticides includes an assessment of the leaching risk posed by pesticides and their degradation products (DP) with the aim of avoiding any unacceptable influence on groundwater. Twelve-year's results of the Danish Pesticide Leaching Assessment Programme reveal shortcomings to the procedure by having assessed leaching into groundwater of 43 pesticides applied in accordance with current regulations on agricultural fields, and 47 of their DP. Three types of leaching scenario were not fully captured by the procedure: long-term leaching of DP of pesticides applied on potato crops cultivated in sand, leaching of strongly sorbing pesticides after autumn application on loam, and leaching of various pesticides and their DP following early summer application on loam. Rapid preferential transport that bypasses the retardation of the plow layer primarily in autumn, but also during early summer, seems to dominate leaching in a number of those scenarios. PMID:25771345

Rosenbom, Annette E; Olsen, Preben; Plauborg, Finn; Grant, Ruth; Juhler, René K; Brüsch, Walter; Kjær, Jeanne

2015-06-01

164

Development of smart spray systems to enhance delivery of pesticides in field nursery production  

Technology Transfer Automated Retrieval System (TEKTRAN)

Two smart sprayer prototypes have been developed and are being evaluated with a goal of increasing pesticide application efficiency and minimizing environmental impact in field nursery production sites. The first prototype, a modified hydraulic vertical boom system, utilizes ultrasonic sensors to d...

165

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

USGS Publications Warehouse

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

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

2012-01-01

166

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

Federal Register 2010, 2011, 2012, 2013, 2014

...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...

2013-01-16

167

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

PubMed

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

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

2013-10-01

168

What Is a Pesticide?  

MedlinePLUS

... pesticides. All of these common products are considered pesticides: Cockroach sprays and baits Insect repellents for personal use. Rat and other rodent poisons. Flea and tick sprays, powders, and pet collars. ... and benefits of pesticides? By their very nature, most pesticides create some ...

169

Structure elucidation of thermal degradation products of amlodipine.  

PubMed

Thermal degradation of amlodipine base causes intramolecular reactions affording three cyclic products, referred to as AMLDEG-I, AMLDEG-II, and AMLDEG-III, respectively. AMLDEG-I is a cyclized product formed by intramolecular elimination of ammonia from amlodipine. AMLDEG-II is a positional isomer of AMLDEG-I. AMLDEG-III is also intramolecular cyclisation product. The three degradation products were isolated by column chromatography and characterized by FT-IR and 1H and 13C NMR spectroscopy data. The AMLDEG-III was crystallized and its structure was solved by single crystal X-ray diffraction (SXRD). PMID:17559164

Lakshmi Devi, A Siva; Srinivasa Rao, Y; Satish, M; Jyothi, G; Babu Rao, K; Omdutt, T

2007-08-01

170

Effect of agricultural pesticides on the degradation of medium spill concentrations of Bonny light crude oil in a tropical rain forest soil  

Microsoft Academic Search

The effect of three agricultural pesticides; K-othrin (deltamethrin), dichlorvos (2,2 dichlorovinydimethy phosphate) and carbofuran (2,3-dihydro-2,2-dimethylbenzofuran-7-y1methylcarbamate, on the degradation of medium spill concentrations of Bonny light crude oil in a tropical rain forest soil in the Niger Delta was investigated. Hydrocarbon (crude oil) loss within a 56-day period was monitored using photometric method. Mineralization (ultimate biodegradation) for the same period was

L. O. Odokuma; F. C. Akubuenyi

2008-01-01

171

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

PubMed

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

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

2014-01-01

172

Pesticides: Protecting Workers  

MedlinePLUS

... assessment Risk management Worker safety program Related information Risk Assessment The first step in the process of EPA’s pesticide product registration is the development of a risk assessment based on the proposed product uses. Pesticide producers ...

173

78 FR 24195 - Product Cancellation Order for Certain Pesticide Registrations  

Federal Register 2010, 2011, 2012, 2013, 2014

...technical allethrins products to formulate any end use products will be permitted...allethrins end use products listed in Table...human health, and agricultural advocates; the...interested in the sale, distribution, or use of...

2013-04-24

174

78 FR 57388 - Product Cancellation Order for Certain Pesticide Registrations  

Federal Register 2010, 2011, 2012, 2013, 2014

...listed manufacturing products to formulate any end use products will be permitted...for the end use products listed in Table...human health, and agricultural advocates; the...interested in the sale, distribution, or use of...

2013-09-18

175

76 FR 16417 - Product Cancellation Order for Certain Pesticide Registrations  

Federal Register 2010, 2011, 2012, 2013, 2014

...human health, and agricultural advocates; the chemical...registrants, of 46 products registered under FIFRA...Registrants of Cancelled Products...Agri Packaging & Logistics, Inc., 2509 South...voluntary cancellations of products listed in Table 1...

2011-03-23

176

Tuning the band gap of mesoporous Zr-doped TiO2 for effective degradation of pesticide quinalphos.  

PubMed

This paper has focused on the synthesis and modification of TiO2 nanomaterial via an acid modified sol-gel process. ZrOCl2 was used as a source of Zr for doping titania. The nanomaterials were characterized by electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, N2 adsorption-desorption isotherms, UV-visible diffuse reflectance spectroscopy, etc. Changes in the band gap of the synthesized nanomaterials were studied with respect to the dopant amount, and the performance of the synthesized nanomaterials was evaluated as a photocatalyst to degrade pesticide quinalphos in aqueous solution under UV light. Anatase TiO2 nanocrystallites with an average size of ca. 8-11 nm were obtained depending on the amount of dopant. The results showed that the amount of dopant significantly altered the band gap as well as the surface properties of the hybrid nanomaterials which resulted in high photocatalytic activity. PMID:23970021

Goswami, Pallabi; Ganguli, Jatindra Nath

2013-10-28

177

Facile synthesis of hierarchical porous TiO(2) ceramics with enhanced photocatalytic performance for micropolluted pesticide degradation.  

PubMed

In this research, hierarchical porous TiO2 ceramics were successfully synthesized through a camphene-based freeze-drying route. The well-dispersed TiO2 slurries were first frozen and dried at room temperature, followed by high-temperature sintering. The ceramics were analyzed by X-ray diffraction, Raman spectroscopy, scanning electron microscopy, and transmission electron microscopy. Results indicated that the obtained TiO2 ceramics could inhibit undesirable anatase-to-rutile phase transformation and grain growth even at temperatures as high as 800 °C. In this experiment, optimal compressive strength and porosity of the TiO2 ceramics were produced with the initial TiO2 slurry content of ?15 wt %. The resultant TiO2 ceramics performed excellently in the photodegradation of atrazine and thiobencarb, and the total organic carbon removal efficiency was up to 95.7% and 96.7%, respectively. More importantly, the TiO2 ceramics were easily recyclable. No obvious changes of the photocatalytic performance were observed after six cycles. Furthermore, the ceramics also effectively degraded other pesticides such as dimethoate, lindane, dipterex, malathion, and bentazone. These hierarchical porous TiO2 ceramics have potential applications in environmental cleanup. PMID:25198508

Xing, Zipeng; Zhou, Wei; Du, Fan; Zhang, Linlin; Li, Zhenzi; Zhang, Hang; Li, Wei

2014-10-01

178

Combination of synthetic and natural products as pesticides (CSYNAP): a new class of antifungal agents.  

PubMed

In the present communication some dehydrated dialdol products such as 1, 5 - Diphenyl pent - 1, 4 - diene - 3 - one (A1); 1, 9 - Diphenylnon - 1, 3, 6, 8 - tetraene - 5 - one (A2); 1, 5 - di (2 - hydroxyphenyl) pent - 1, 4 - diene - 3 - one (A3); 1, 5 - difuran pent - 1, 4 - diene - 3 - one (A4); 1, 5 - di [4 - bis (N, Ndimethyl) phenyl] pent - 1, 4 - diene - 3 - one (A5) were screened for their antifungal activity. To reduce their adverse effect on the environment, for the first time, we have attempted to screen the antifungal activity of these synthetic compounds in conjunction with selected natural products. The natural products that were used in our study include Nicotine tobaccum and Neem oil (Azadirachta indica). A set of 15 samples was tested against highly pathogenic and of extensive host range fungi Sclerotium rolfsii, Rhizactonia bataticola, Fusarium udum. The filter paper disc assay to monitor antifungal effect revealed significant and interesting results. We found that the use of the combination of natural and synthetic pesticides is more effective and environmentally healthy compared to just synthetic chemicals and/or less available natural products. These results obtained from the combined use of natural and synthetic chemicals lead us to suggest to a new class of less toxic but more effective pesticides. We call it group as CSYNAP, i. e. Combination of SYnthetic and NAtural products as Pesticides. PMID:21469500

Rani, Archna; Jain, Sapna; Dureja, Prem; Tripathi, Praveen K; Singh, Kamalendra

179

Screening of nerve agent degradation products by MALDI-TOFMS.  

PubMed

A novel method for the rapid screening of degradation products derived from nerve agents by matrix-assisted laser desorption ionization time-of-flight mass spectrometry is described. Five standard products were selected as model compounds, including isopropyl methylphosphonic acid (IMPA), pinacolyl methylphosphonic acid (PMPA), ethyl methylphosphonic acid (EMPA), isobutyl methylphosphonic acid (i-BuMPA), and cyclohexyl methylphosphonic acid (CHMPA), which are degradation products of Sarin (GB), Soman (GD), VX, Russian VX (RVX), and GF, respectively. For comparison, CHCA (alpha-cyano-4-hydroxycinnamic acid) and DCCA (7-(diethylamino)coumarin-3-carboxylic acid) were used as the MALDI-matrix when the third harmonic generation (355 nm) of a Nd:YAG laser and a hydrogen Raman laser (multifrequency laser) were used, respectively. The method permitted the five nerve agent degradation products to be screened rapidly and successfully, suggesting that it has the potential for use as a routine monitoring tool. PMID:16808484

Shu, You-Ren; Su, An-Kai; Liu, Ju-Tsung; Lin, Cheng-Huang

2006-07-01

180

Production of lignocellulose-degrading enzymes and degradation of leaf litter by saprotrophic basidiomycetes isolated from a Quercus petraea forest  

Microsoft Academic Search

Due to the production of lignocellulose-degrading enzymes, saprotrophic basidiomycetes can significantly contribute to the turnover of soil organic matter. The production of lignin- and polysaccharide-degrading enzymes and changes of the chemical composition of litter were studied with three isolates from a Quercus petraea forest. These isolates were capable of fresh litter degradation and were identified as Gymnopus sp., Hypholoma fasciculare

Vendula Valášková; Jaroslav Šnajdr; Britta Bittner; Tomáš Cajthaml; V?ra Merhautová; Martin Hofrichter; Petr Baldrian

2007-01-01

181

A study of the products of PVC thermal degradation  

Microsoft Academic Search

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

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

1995-01-01

182

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

USGS Publications Warehouse

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

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

2008-01-01

183

Studies on Rapid Multi-Residue Analysis of Pesticides in Agricultural Products by LC-MS/MS.  

PubMed

Rapid multi-residue analysis of pesticides in agricultural products was studied by using LC-MS/MS. Pesticide residues in 10 g of homogenized agricultural products were extracted with 30 mL of acetonitrile and salted out with 4 g of anhydrous magnesium sulfate and 1 g of sodium chloride in the presence of citrate salts for buffering in a disposable tube. Co-extractives were removed by use of our original triple layered column (C18/GC/PSA; 60/30/60 mg).According to the method validation guideline of the Ministry of Health, Labour and Welfare of Japan, we conducted recovery tests in 5 kinds of agricultural products (brown rice, kiwi, cabbage, sweet potato and spinach) spiked with 60 pesticides at the level of 0.01 or 0.1 ?g/g. Each concentration of pesticide spiked was extracted from 2 samples per day on 5 days. Pesticides in the test solution were determined by two types of LC-MS/MS using scheduled MRM.Using this method, 58 out of 60 pesticides satisfied the guideline criteria in brown rice, 59 in kiwi, 55 in cabbage, 55 in sweet potato and 56 in spinach. This method is applicable for routine examination of pesticide residues in agricultural products. PMID:25743588

Iwakoshi, Keiko; Tamura, Yasuhiro; Otsuka, Kenji; Tomizawa, Sanae; Yamaki, Yumiko; Masubuchi, Tamako; Nakagawa, Yukiko; Masuda, Ryoko; Sato, Chizuko; Sasamoto, Takeo; Takano, Ichiro

2014-01-01

184

78 FR 38326 - Product Cancellation Order for Certain Pesticide Registrations  

Federal Register 2010, 2011, 2012, 2013, 2014

...last resmethrin product registrations in the United States. Any distribution, sale, or use of the products subject to this...human health, and agricultural advocates; the...interested in the sale, distribution, or use of...

2013-06-26

185

Phosphate and soil binding: factors limiting bacterial degradation of ionic phosphorus-containing pesticide metabolites.  

PubMed Central

Soils that had a high binding capacity for inorganic orthophosphate (Pi) had reduced capacities to bind ionic alkyl phosphorus compounds. Only ionic methylphosphonate (MPn) and ionic phenylphosphonate exhibited moderate binding. Pseudomonas testosteroni used either MPn or Pi as a sole phosphorus source and exhibited diauxic utilization of MPn and Pi. The utilization of MPn was suppressed in the presence of Pi. This suppression was abolished by a Pi-binding soil. The soil did not have a significant effect on the maximum rate of degradation of either MPn or the poorly bound ionic O-isopropyl methylphosphonate, whereas the amount of MPn (but not the amount of O-isopropyl methylphosphonate) metabolized was reduced in the presence of soil PMID:453832

Daughton, C G; Cook, A M; Alexander, M

1979-01-01

186

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

Microsoft Academic Search

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

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

2005-01-01

187

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 ...

188

Pesticides in Ground Water of Central and Western Maryland  

USGS Publications Warehouse

Selected pesticides and degradates (products of pesticide degradation) are detectable in ground water in many parts of central and western Maryland, although concentrations are generally less than 0.1 micrograms per liter. Ground-water samples collected recently (1994-2003) from 72 wells in areas of Maryland underlain by consolidated carbonate, crystalline, or siliciclastic aquifers (areas north and west of the Fall Line) were analyzed for selected pesticides and degradates. Pesticides were typically detected in mixtures of multiple compounds in ground water, and degradates were commonly detected, often at greater concentrations than their respective parent compounds. No pesticides were observed at concentrations greater than established standards for drinking water, and nearly all observed concentrations were below other health-based guidelines. Although such standards and guidelines are generally much greater than measured concentrations in ground water, they do not exist for many detected compounds (particularly degradates), or for mixtures of multiple compounds. The distribution of pesticides and degradates in ground water is related to application practices, as well as chemical and environmental factors that affect the fate and movement of individual compounds.

Ator, Scott W.; Reyes, Betzaida

2008-01-01

189

Chiral pesticides: identification, description, and environmental implications.  

PubMed

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

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

2012-01-01

190

Occurrence of Isoxaflutole, Acetamide, and Triazine Herbicides and Their Degradation Products in 10 Iowa Rivers Draining to the Mississippi and Missouri Rivers, 2004  

USGS Publications Warehouse

During 2004, a study to document the occurrence of herbicides and herbicide degradation products was conducted for 10 major Iowa rivers draining to the Missouri and Mississippi Rivers. Seventy-five water-quality samples were collected to measure isoxaflutole, acetamide, and triazine herbicides and their herbicide degradation products. An analytical method to measure isoxaflutole and its degradation products, diketonitrile and benzoic acid, was developed by the U.S. Geological Survey Organic Geochemistry Research Laboratory in Lawrence, Kansas, using vacuum manifold solid-phase extraction and liquid chromatography/mass spectrometry/mass spectrometry and is described in this report. Isoxaflutole, a low application rate preemergence herbicide for control of annual broadleaf weeds, is used extensively in Iowa. Findings from the study documented in this report indicate that isoxaflutole was designed to degrade quickly to diketonitrile, which appears to be more stable, and then to benzoic acid. Of the 75 samples collected to measure isoxaflutole, there were four detections of isoxaflutole, 53 detections of diketonitrile, and 41 detections of benzoic acid. Also, results of acetamide and triazine water-quality samples correlate with past studies, which indicate that herbicide degradation products are detected more frequently and often at higher concentrations in surface water than their parent compounds. In addition to analysis of isoxaflutole and its degradation products, samples were analyzed by the USGS National Water-Quality Laboratory schedule 2001 for about 52 pesticides and their degradation products.

Scribner, Elisabeth A.; Meyer, Michael T.; Kalkhoff, Stephen J.

2006-01-01

191

Development of a sensor for polypropylene degradation products.  

SciTech Connect

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.

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

2009-04-01

192

75 FR 54147 - Product Cancellation Order for Certain Pesticide Registrations  

Federal Register 2010, 2011, 2012, 2013, 2014

...75771-1, registered under FIFRA section 3. Cancellation of the product, Biter Figher, containing the chemicals calcium lactate and urea, was requested by the registrant, Ticks or Mosquitoes, [[Page 54148

2010-09-03

193

75 FR 82387 - Product Cancellation Order for Certain Pesticide Registrations  

Federal Register 2010, 2011, 2012, 2013, 2014

...Whitmire Micro-Gen Research Laboratories, Inc., 3568 Tree...No. 100-723) and the Whitmire Micro-Gen Research Laboratories, Inc.'s end-use...the canceled product. Whitmire Micro-Gen Research Laboratories, Inc. is...

2010-12-30

194

Identification and measurement of pesticide contaminants in food products by electron impact GC/MS  

NASA Astrophysics Data System (ADS)

The paper concern is determination of eight pesticides in food products samples. The target compounds are: Lindane, Heptachlor, Aldrin, o,p-DDE, Dieldrin, Endrin, p,p'-DDT, and Methoxychlor. The compounds quantities were performed from chromatographic area obtained in full scan GC/MS mode after baseline separation and by comparation with surrogate internal standard area (Diphenylamine). The samples were concentrated by extraction with organic solvents (acetone) by Solid-Liquid Extraction (SLE) procedures the recovery factors being better than 80% except for Heptachlors. The coefficient of correlation of detector response function was better than 0.913 and LOQ under 0.015 ?g/g. The method enables to determine pesticides at low ?g/g in food supplements.

Tusa, Florina; Moldovan, Zaharie; Vlassa, Mircea

2009-08-01

195

The quantity and quality of dissolved organic matter as supplementary carbon source impacts the pesticide-degrading activity of a triple-species bacterial biofilm.  

PubMed

Effects of environmental dissolved organic matter (eDOM) that consists of various low concentration carbonic compounds on pollutant biodegradation by bacteria are poorly understood, especially when it concerns synergistic xenobiotic-degrading consortia where degradation depends on interspecies metabolic interactions. This study examines the impact of the quality and quantity of eDOM, supplied as secondary C-source, on the structure, composition and pesticide-degrading activity of a triple-species bacterial consortium in which the members synergistically degrade the phenylurea herbicide linuron, when grown as biofilms. Biofilms developing on 10 mg L?¹ linuron showed a steady-state linuron degradation efficiency of approximately 85 %. The three bacterial strains co-localized in the biofilms indicating syntrophic interactions. Subsequent feeding with eDOM or citrate in addition to linuron resulted into changes in linuron-degrading activity. A decrease in linuron-degrading activity was especially recorded in case of co-feeding with citrate and eDOM of high quality and was always associated with accumulation of the primary metabolite 3,4-dichloroaniline. Improvement of linuron degradation was especially observed with more recalcitrant eDOM. Addition of eDOM/citrate formulations altered biofilm architecture and species composition but without loss of any of the strains and of co-localization. Compositional shifts correlated with linuron degradation efficiencies. When the feed was restored to only linuron, the linuron-degrading activity rapidly changed to the level before the mixed-substrate feed. Meanwhile only minor changes in biofilm composition and structure were recorded, indicating that observed eDOM/citrate effects had been primarily due to repression/stimulation of linuron catabolic activity rather than to biofilm characteristics. PMID:23653124

Horemans, Benjamin; Vandermaesen, Johanna; Breugelmans, Philip; Hofkens, Johan; Smolders, Erik; Springael, Dirk

2014-01-01

196

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...

197

Management Practices to Improve Productivity of Degraded/Eroded Soils  

Technology Transfer Automated Retrieval System (TEKTRAN)

Productivity of degraded/eroded soils can be restored by using organic amendment, such as manure, and improved soil management. A study is being conducted near Hays, KS, to investigate and compare restorative potential of two nitrogen (N) sources. Dried beef manure and urea fertilizer were each appl...

198

Sources and Input Pathways of Glyphosate and its Degradation Product AMPA  

NASA Astrophysics Data System (ADS)

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

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

2009-04-01

199

Photocatalytic degradation of organic pollutants with simultaneous production of hydrogen  

Microsoft Academic Search

The photocatalytic degradation of a number of organic compounds in solution, including alcohols and organic acids, has been investigated under unaerated conditions with the use of Pt\\/TiO2 photocatalyst and solar or UV irradiation. It has been found that production of CO2 is in all cases accompanied by evolution of hydrogen, the production rate of which is significantly enhanced, compared with

Alexia Patsoura; Dimitris I. Kondarides; Xenophon E. Verykios

2007-01-01

200

Life- cycle assessment in pesticide product development: methods and case study on two plant-growth regulators from different product generations.  

PubMed

Environmental assessments in pesticide product development are generally restricted to plant uptake and emissions of active ingredients. Life-cycle assessment (LCA) enables a more comprehensive evaluation by additionally assessing the impacts of pesticide production and application (e.g. tractor operations). The use of LCA in the product development of pesticides, in addition to the methods commonly applied, is therefore advisable. In this paper a procedure for conducting LCA in early phases of product development is proposed. In a case study, two plant-growth regulators from different product generations were compared regarding their application in intensive production of winter wheat. The results showed thatthe reduced emissions from active ingredients of the newer pesticide were compensated by higher impacts from the production process. The authors draw the conclusion that it is important to consider environmental objectives in the procurement of precursors, in addition to the classical goals of increasing the efficacy and reducing the nontarget effects of pesticides. Moreover, the case study showed that decisions based on uncertain results in early stages of product development may need to be revised in later stages, e.g. based on investigations of pesticides' effects on crop yield. PMID:15871283

Geisler, Georg; Hellweg, Stefanie; Hofstetter, Thomas B; Hungerbuehler, Konrad

2005-04-01

201

Pesticide Use and Mycotoxin Production in Fusarium and Aspergillus Phytopathogens  

Microsoft Academic Search

The major mycotoxigenic species of Fusarium and Aspergillus phytopathogens have been identified in this review. Since fungicides are widely used to control crop diseases caused by these fungi, it is pertinent to assess efficacy with respect to mycotoxin production. In both laboratory studies with pure cultures of phytopathogens and field trials with crop plants, the overall evidence concerning the effectiveness

J. P. Felix D'Mello; Ann M. C. Macdonald; David Postel; Wilko T. P. Dijksma; Aude Dujardin; Cristina M. Placinta

1998-01-01

202

78 FR 24197 - Product Cancellation Order for Certain Pesticide Registrations  

Federal Register 2010, 2011, 2012, 2013, 2014

...066330-00337................ Micro Flo Permethrin Permethrin. 3.2 AG. 066330-00376...Products Company, 5 Roger Ave., Milford, CT 06460- 6436. 62719 (AL020006; AR020003...AMVAC Chemical Corporation, 4695 MacArthur Ct., Suite 1200, Newport Beach, CA...

2013-04-24

203

Cloning and expression of ophB gene encoding organophosphorus hydrolase from endophytic Pseudomonas sp. BF1-3 degrades organophosphorus pesticide chlorpyrifos.  

PubMed

Chlorpyrifos is an organophosphate pesticide that has adverse effect on animals and plants. We isolated endophytic bacterial strain, Pseudomonas sp. BF1-3, from balloon flower root which can hydrolyze chlorpyrifos. A gene (ophB) encoding a protein involved in chlorpyrifos degradation from this strain was cloned into Escherichia coli DH5? for confirming enzyme activity. After sequencing, total 1024bp nucleotide sequences were found in the open reading frame of ophB. The chlorpyrifos degradation patterns by E. coli DH5? (ophB) were observed. During incubation in minimal salt (M9) medium supplemented with chlorpyrifos (100mgL(-1)), the E. coli DH5? harboring ophB degraded about 97% initial chlorpyrifos (100mgL(-1)) and accumulated 86mgL(-1) 3,5,6-trichloro-2-pyridinol (TCP) within 9 days. In addition, optical density (OD) of E. coli DH5? (ophB) culture at 600nm was increased from 0.172 to 1.118 within 2 days of inoculation in the chlorpyrifos supplemented M9 medium. The estimated molecular weight of purified OphB protein was determined to be 31.4kDa by SDS-PAGE. The OphB enzyme was most active at pH 8 and an optimal temperature around 35°C. These results indicate that endophytic bacteria are supposed to be useful for biological control of environments contaminated with pesticides. PMID:25062445

Barman, Dhirendra Nath; Haque, Md Azizul; Islam, Shah Md Asraful; Yun, Han Dae; Kim, Min Keun

2014-10-01

204

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

SciTech Connect

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

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

2011-07-15

205

Potable water production from pesticide contaminated surface water—A membrane based approach  

Microsoft Academic Search

The aim of the present study is to obtain safe and pure drinking water from surface water, which has been polluted with pesticide. Pesticide contaminated surface water samples were prepared by spiking commonly used pesticide, Isoproturon, in different surface water samples collected from different parts of India. Attempts were made to evaluate the efficiency of different adsorbents in removing pesticide

Baisali Sarkar; N. Venkateshwarlu; R. Nageswara Rao; Chiranjib Bhattacharjee; Vijay Kale

2007-01-01

206

Comparative aspects of pesticide metabolism in plants and animals.  

PubMed Central

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

Menn, J J

1978-01-01

207

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

USGS Publications Warehouse

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

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

2007-01-01

208

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

PubMed

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

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

2011-07-01

209

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

PubMed

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

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

2014-02-01

210

Community air monitoring for pesticides. Part 3: using health-based screening levels to evaluate results collected for a year.  

PubMed

The CA Department of Pesticide Regulation (CDPR) and the CA Air Resources Board monitored 40 pesticides, including five degradation products, in Parlier, CA, to determine if its residents were exposed to any of these pesticides and, if so, in what amounts. They included 1,3-dichloropropene, acrolein, arsenic, azinphos-methyl, carbon disulfide, chlorpyrifos and its degradation product, chlorthalonil, copper, cypermethrin, diazinon and its degradation product, dichlorvos, dicofol, dimethoate and its degradation product, diuron, endosulfan and its degradation product, S-ethyl dipropylcarbamothioate (EPTC), formaldehyde, malathion and its degradation product, methyl isothiocyanate (MITC), methyl bromide, metolachlor, molinate, norflurazon, oryzalin, oxyfluorfen, permethrin, phosmet, propanil, propargite, simazine, SSS-tributylphosphorotrithioate, sulfur, thiobencarb, trifluralin, and xylene. Monitoring was conducted 3 days per week for a year. Twenty-three pesticides and degradation products were detected. Acrolein, arsenic, carbon disulfide, chlorpyrifos, copper, formaldehyde, methyl bromide, MITC, and sulfur were detected in more than half the samples. Since no regulatory ambient air standards exist for these pesticides, CDPR developed advisory, health-based non-cancer screening levels (SLs) to assess acute, subchronic, and chronic exposures. For carcinogenic pesticides, CDPR assessed risk using cancer potency values. Amongst non-carcinogenic agricultural use pesticides, only diazinon exceeded its SL. For carcinogens, 1,3-dichloropropene concentrations exceeded its cancer potency value. Based on these findings, CDPR has undertaken a more comprehensive evaluation of 1,3-dichloropropene, diazinon, and the closely related chlorpyrifos that was frequently detected. Four chemicals-acrolein, arsenic, carbon disulfide, and formaldehyde-sometimes used as pesticides were detected, although no pesticidal use was reported in the area during this study. Their presence was most likely due to vehicular or industrial emissions. PMID:24370859

Wofford, Pamela; Segawa, Randy; Schreider, Jay; Federighi, Veda; Neal, Rosemary; Brattesani, Madeline

2014-03-01

211

Surface detection of chemical warfare agent simulants and degradation products  

Microsoft Academic Search

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

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

2005-01-01

212

What does the difference in the terbuthylazine degradation rate in selected soils of Apace Valley catchment means for the pesticide leaching potential?  

NASA Astrophysics Data System (ADS)

The degradation of the selected pesticide terbuthylazine was investigated in the three different soil samples, which occurs frequently in agricultural area of Apace valley (53 km2), Slovenia. Selected soil samples were similar in organic matter content (1.9-2.1 %), pH (4.5-5.3), and in C/N ratio (7-9); whereas differed in texture (silty loam and loam) and in pesticide usage history (»integrated« and intensive soil management). Triazine herbicides were intensively used for several years in high rates in soil sample S9+, which consisted of 9 % of sand, 65 % of silt, and 26 % of clay. The other two soil samples, S8 (8 % sand, 72 % silt, 20 % clay) and S45 (45 % sand, 44% slit, 11 % clay), were not treated with triazine herbicide for 2 years before experiment. The degradation experiment was conducted under constant laboratory conditions using 14C-ring labelled terbuthylazine. Volatile 14C-compounds, including 14CO2 released after 14C-terbuthylazine mineralization, have been measured three times a week. Two months after terbuthylazine application, the total amount of 14C in soil samples, bound residues as well as extracted terbuthylazine and its metabolites were determined. Cumulative mineralization was from 5 to16 % of applied terbuthylazine. The highest cumulative mineralization was in soil sample S9+, soil sample with the most intensive pesticide usage; hence the lag phase was the shortest. Interestingly, the cumulative mineralization was similar also in soil sample S45 (14% of applied terbuthylazine), however the lag phase in this soil was much longer and comparable to soil S8. Leaching potential of terbuthylazine in Apace Valley catchment was assessed with model PELMO 3.22, using soil and long-term climate data of the Apace Valley. Results will be presented in the conference.

Suhadolc, Marjetka; Sibanc, Natasa; Lobnik, Franc

2010-05-01

213

Study on fluorescent property of degrading products of piperacillin and its analytical application  

NASA Astrophysics Data System (ADS)

The fluorimetric property of the degrading products of piperacillin has been studied in detail. The studies on degrading pH, degrading time, detection alkalinity and other corresponding analytical parameters of acid degradation have been made. Then fluorometry of piperacillin was established by producing its stable fluorescent products. The detection limit for acid degradation analytical method is 2.34 ng/ml, the linear range is 7.80-4.0×10 2 ppb. The analytical sensitivity, precision and stability of degrading products of acid degradation are satisfactory, which has been used for the determination of the trace piperacillin in human serum and urine with satisfactory results.

Tang, Bo; Ma, Li; Sun, Yue; Wang, Huai-you

2001-02-01

214

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

EPA Science Inventory

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

215

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 ...

216

Halotolerance, ligninase production and herbicide degradation ability of basidiomycetes strains  

PubMed Central

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

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

2013-01-01

217

Gamma radiolytic degradation of the endrin insecticide in methanol and monitoring of radiolytic degradation products by HPLC  

Microsoft Academic Search

The objective of this investigation was to verify the degradation of endrin by gamma irradiation. 60Co was used as radiation source for irradiation of 50 mg L?1 endrin with a varied dose of 1–6 kGy. High performance liquid chromatography (HPLC) coupled with diode array detector was\\u000a used as an analytical technique to monitor the degradation rate along with numbers of degradation products formed.

M. Riaz; S. Bilal Butt

2010-01-01

218

Electrospray ionization mass spectrometry (ESI-MS) monitoring of the photolysis of diazinon in aqueous solution: degradation route and toxicity of by-products against Artemia salina.  

PubMed

The photolytic degradation of diazinon, an organophosphorus pesticide, in aqueous medium under assorted pH values was continuously monitored by direct infusion electrospray ionization mass spectrometry (ESI-MS). The results indicated that the UV radiation was quite efficient in promoting the pesticide degradation at the three pH levels evaluated (5, 7 and 8). The m/z of the most abundant ions observed in the mass spectra (MS), in conjunction with the fragmentation patterns of such ionic species (MS/MS data), made possible the proposition of chemical structures for the main by-products formed. As a result, routes for the photodegradation of diazinon in aqueous solution could thus be suggested. In the assays using Artemia salina (brine shrimp) it was verified that the photodegradation products exhibited much lower toxicity than the primary substrate. Aiming at mimicking the conditions ordinarily found in water treatment plants, an additional series of tests was conducted with a solution containing sodium hypochlorite and diazinon. This solution, when not exposed to UV radiation, exhibited high toxicity against the microorganisms. Under the influence of UV radiation, however, the toxicity rates decreased dramatically. This result is relevant because it points toward the confident application of UV radiation to neutralize the deleterious effects caused by diazinon (and perhaps other organophosphorus pesticides) as well as sodium hypochlorite to the environment. PMID:23356337

Souza, Amauri G; Cardeal, Zenilda L; Augusti, Rodinei

2013-01-01

219

Adsorption of ionisable pesticides in soils.  

PubMed

Understanding the fate of a pesticide in soil is fundamental to the accurate assessment of its environmental behaviour and vital in ensuring the safe use of new and existing products. Ionisable pesticides comprise a significant proportion of both existing and new active substances registered for use in agriculture worldwide. This group of pesticides includes chemicals that are frequently found in groundwater and surface waters in many different countries. Despite this, approaches to predict the influence of soil properties on the behaviour of ionisable pesticides in soils are poorly developed. Current regulatory assessments frequently default to methods developed for nonionic chemicals, although it is evident that ionisable compounds do not often react like neutral molecules. This review presents the state of knowledge on the adsorption of ionisable pesticides in soils. It first introduces the issues concerning adsorption and the characteristics of this particular kind of chemical. The mechanisms postulated for the adsorption of ionisable pesticides are then described: these are hydrophobic partitioning, ionic exchange, charge transfer, ligand exchange, cation or water bridging, and the formation of bound residues. Relatively little experimental evidence is available, and we are still unable to determine the quantitative contribution of each process in a particular situation. Knowledge is still lacking concerning phenomena occurring at the surfaces of soil particles. Measurements do not allow determination of the operative pH at the surface of soil particles or in microenvironments, and the influence of ionic strength or competition effects is difficult to assess. Subsequently, the review focuses on the influence of soil properties on adsorption and on potential to predict the behaviour of ionisable pesticides in soils. Unlike hydrophobic compounds, adsorption of ionisable pesticides is highly sensitive to variation in pH. This relationship mainly derives from the different proportion of ionic and neutral forms of the pesticide present at each pH level but also from the presence of surfaces with pH-dependent charges in soils. Soil organic matter generally promotes adsorption, although a negative influence has sometimes been reported. Clay and oxides can also play a significant role in some cases. So far, no modelling approach has been applied successfully to a range of ionisable pesticides to predict their adsorption in soils. The standardization of experimental settings and the application of approaches specific to a particular class of pesticide or different type of soil might be necessary to describe the complexity of interactions among ionisable molecules. Degradation of ionisable pesticides is influenced by soil pH in a particular way that relates to changes in sorption, changes in composition and activity of the microbial community, and to shifts in the balance between different degradative mechanisms. PMID:17016919

Kah, M; Brown, C D

2006-01-01

220

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

NASA Astrophysics Data System (ADS)

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

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

2005-12-01

221

Molecular products from the thermal degradation of glutamic acid.  

PubMed

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

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

2013-08-14

222

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

PubMed

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

Bajwa, Usha; Sandhu, Kulwant Singh

2014-02-01

223

Unusual surface degradation products grown on archaeological bronze artefacts  

NASA Astrophysics Data System (ADS)

Within the framework of the EFESTUS project funded by the European Commission a large number of Cu-based archaeological artefacts from the Mediterranean basin have been studied to investigate their chemical composition, metallurgical features and corrosion products nature (i.e. the patina). By means of the combined use of X-ray photoelectron spectroscopy (XPS), optical microscopy (OM), scanning electron microscopy with energy dispersive X-ray spectrometry (SEM-EDS) and X-ray diffraction (XRD) the bronze artefacts have been studied for the detailed identification of the corrosion products and their micro-chemical structure in order to achieve information about degradation agents and mechanisms. In the present work, some examples of unusual corrosion products formed on the objects during the long-term burial are presented and related to the peculiar local context revealing the strong interaction between the bronze artefact and the chemical components found in the archaeological site.

Mezzi, A.; de Caro, T.; Riccucci, C.; Faraldi, F.; Veroli, C.; Caschera, D.

2013-12-01

224

Antimicrobial Pesticides  

NSDL National Science Digital Library

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

225

Vibrational spectroscopy for online monitoring of extraction solvent degradation products  

SciTech Connect

In our research, we are exploring the potential of online monitoring of the organic solvents for the flowsheets relevant to the used nuclear fuel reprocessing and tributyl phosphate (TBP)- based extraction processes in particular. Utilization of vibrational spectroscopic techniques permits the discrimination of the degradation products from the primary constituents of the loaded extraction solvent. Multivariate analysis of the spectral data facilitates development of the regression models for their quantification in real time and potentially enables online implementation of a monitoring system. Raman and FTIR spectral databases were created and used to develop the regression partial least squares (PLS) chemometric models for the quantitative prediction of HDBP (dibutyl phosphoric acid) degradation product, TBP, and UO{sub 2}{sup 2+} extraction organic product phase. It was demonstrated that both these spectroscopic techniques are suitable for the quantification of the Purex solvent components in the presence of UO{sub 2}(NO{sub 3}){sub 2}. Developed PLS models successfully predicted HDBP and TBP organic concentrations in simulated Purex solutions.

Peterson, J.; Robinson, T.; Bryan, S.A.; Levitskaia, T.G. [Pacific Northwest National Laboratory, 902 Battelle Blvd, PO Box 999, MSIN P7-25 Richland, WA 99352 (United States)

2013-07-01

226

[Multiresidue analysis of nitrogen-containing and sulfur-containing pesticides in agricultural products using dual-column GC-NPD/FPD].  

PubMed

We investigated simultaneous analytical methods for pesticide residues in large numbers of agricultural products samples. Extraction of each sample with acetonitrile was followed by a salting-out step using a graduated cylinder. The test solution was cleaned up with gel permeation chromatography (GPC), which separated the pesticide eluate into 2 fractions, and then with a tandem mini-column. Analysis was done with a dual-column GC equipped with a dual NPD and FPD (S mode) detector. Use of the Siltek-deactivated liner, guard column, and Y connector, and Silcosteel-treated NPD jet was effective for preventing the breakdown of sulfur-containing pesticides. Recoveries of 87 nitrogen-containing and sulfur-containing pesticides from fortified spinach, tomato, apple, strawberry and brown rice, ranged from 71 to 127% with RSD values of 1-24%, except for recoveries of aldicarb, amitraz, ethiofencarb, imazalil, propamocarb and triflumizole. Detection limits of pesticides were very good (0.3-5 ppb (NPD) and 2-20 ppb (FPD)) for routine analysis of pesticide residues in foods. Surveillance of pesticides in agricultural products was carried out by using the present method. From 22 out of 33 samples, 21 pesticides (43 in total) were detected. The results indicated that the present method can be applied as an efficient and reliable means for monitoring pesticide residues in agricultural products. PMID:12092417

Ueno, Eiji; Oshima, Harumi; Saito, Isao; Matsumoto, Hiroshi

2002-04-01

227

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

PubMed Central

Small-scale farmers in Northern Tanzania grow vegetables that include tomatoes, cabbages and onions and use many types of pesticides to control pests and diseases that attack these crops. Based on the use of questionnaires and interviews that were conducted in Arumeru, Monduli, Karatu, and Moshi rural districts, this study investigates farmers’ practices on vegetable pest management using pesticides and related cost and health effects. The types of pesticides used by the farmers in the study areas were insecticides (59%), fungicides (29%) and herbicides (10%) with the remaining 2% being rodenticides. About a third of the farmers applied pesticides in mixtures. Up to 90% had a maximum of 3 pesticides in a mixture. In all cases there were no specific instructions either from the labels or extension workers regarding these tank mixtures. Fifty three percent of the farmers reported that the trend of pesticide use was increasing, while 33% was constant and 14% was decreasing. More than 50 percent of the respondents applied pesticides up to 5 times or more per cropping season depending on the crop. Insecticides and fungicides were routinely applied by 77% and 7%, respectively by these farmers. Sixty eight percent of farmers reported having felt sick after routine application of pesticides. Pesticide-related health symptoms that were associated with pesticides use included skin problems and neurological system disturbances (dizziness, headache). Sixty one percent of farmers reported spending no money on health due to pesticides. These results can be used to develop a tool to quantify the cost of pesticide use in pest management by small-scale vegetable farmers in Northern Tanzania and contribute to the reformation of pesticide policy for safe and effective use of pesticides. PMID:18528532

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

2007-01-01

228

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

Microsoft Academic Search

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

Patrick L Huston; Joseph J Pignatello

1999-01-01

229

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

PubMed

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

Hossaini, Hiwa; Moussavi, Gholamreza; Farrokhi, Mehrdad

2014-08-01

230

Pesticides and their breakdown products in Lake Waxahachie, Texas, and in finished drinking water from the lake  

USGS Publications Warehouse

Since 1991, the U.S. Geological Survey (USGS) National Water-Quality Assessment (NAWQA) Program has collected pesticide data from streams and aquifers throughout the Nation (Gilliom and others, 1995). However, little published information on pesticides in public drinking water is available. The NAWQA Program usually collects data on the sources of drinking water but not on the finished drinking water. Therefore, the U.S. Environmental Protection Agency (USEPA), in conjunction with the NAWQA Program, has initiated a nationwide pilot project to collect information on concentrations of pesticides and their breakdown products in finished drinking water, in source waters such as reservoirs, and in the basins that contribute water to the reservoirs. The pilot project was designed to collect water samples from finished drinking-water supplies and the associated source water from selected reservoirs that receive runoff from a variety of land uses. Lake Waxahachie, in Ellis County in north-central Texas, was chosen to represent a reservoir receiving water that includes runoff from cotton cropland. This fact sheet presents the results of pesticide sampling of source water from Lake Waxahachie and in finished drinking water from the lake. Analyses are compared to indicate differences in pesticide detections and concentrations between lake water and finished drinking water.

Ging, Patricia B.

2002-01-01

231

Vascular responsiveness to dimethylaminoethyl methacrylate and its degradation products.  

PubMed

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

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

2003-07-01

232

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

PubMed Central

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

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

2012-01-01

233

Capillary electrophoresis separation of the desamino degradation products of oxytocin  

PubMed Central

Oxytocin is an endogenous and therapeutic hormone necessary for maternal health. It is also the subject of fast growing research in the field of behavioral science. This article describes a rapid capillary electrophoresis method using UV detection at 214 nm for the determination of the deamidation products of oxytocin. Deamidation is the most common degradation pathway of peptides and proteins and can lead to reduced therapeutic efficiency of biopharmaceuticals. To achieve a separation of the seven structurally similar desamino peptides from oxytocin, 11 mM sulfobutyl ether ?-cyclodextrin and 10% v/v MeOH were added to a background electrolyte of 50 mM phosphate buffer at pH 6.0. The assay is linear within ?5-100 ?M for all species with a total analysis time of 12 min. The method was then applied to monitor the heat-stress degradation of oxytocin at 70°C, where all seven desamino species were observed over a 96 h period. PMID:24166826

Creamer, Jessica S.; Krauss, Shannon T.; Lunte, Susan M.

2014-01-01

234

Degradation and transformation products of acetaminophen in soil.  

PubMed

Acetaminophen is the most widely used human medicine. Trace levels of acetaminophen are frequently detected in treated wastewater and the impacted surface or groundwater resources. However, even though soil is a primary receiving compartment, the fate of acetaminophen in soil is poorly known, including in particular the potential for the formation of incomplete degradation products that may have altered biological activity and mobility. In this study, using both (14)C-labeling and LC-MS/MS techniques, we evaluated the dissipation routes and transformation pathways of acetaminophen in soils under a range of conditions. Throughout 120-d aerobic incubation, up to 17.0 ± 0.8% of (14)C-acetaminophen was mineralized, but mineralization was greatly inhibited after sterilization or amendment of biosolids. Immediately after treatment, the majority of (14)C-residue became non-extractable or bound, with the level accounting for 73.4-93.3% of the applied amount at the end of incubation. A total of 8 intermediates were identified, including 3-hydroxyacetaminophen, hydroquinone, 1, 4-benzoquinone, N-acetyl-p-benzoquinone imine, p-acetanisidide, 4-methoxyphenol, 2-hexenoic acid, and 1, 4-dimethoxybenzene. Mineralization and rapid conversion to bound residues suggest that acetaminophen is quickly detoxified in soil, decreasing the potential for off-site transport such as leaching or runoff. On the other hand, the formation of a large number of degradation intermediates, and their potential biological activity, may pose unknown risks, such as accumulation into edible plants. This risk warrants further investigation. PMID:24316789

Li, Juying; Ye, Qingfu; Gan, Jay

2014-02-01

235

Caveolin-1–dependent apoptosis induced by fibrin degradation products  

PubMed Central

In mice lacking the blood coagulation regulator thrombomodulin, fibrinolytic degradation products (FDP) of fibrin induce apoptotic cell death of a specialized cell type in the placenta, polyploid trophoblast giant cells. Here, we document that this bioactivity of FDP is conserved in human FDP, is not limited to trophoblast cells, and is associated with an A?-chain segment of fibrin fragment E (FnE). The majority of proapoptotic activity is arginine-glycine-aspartic acid (RGD)-independent and requires caveolin-1–dependent cellular internalization of FnE. Internalization through caveoli is mediated by an epitope contained within A?52-81 that is necessary and sufficient for cellular uptake of FnE. A?52-81 does not cause apoptosis itself, and competitively inhibits FnE internalization and apoptosis induction. Apoptotic activity per se resides within A?17-37 and requires the N-terminal neoepitope generated by release of fibrinopeptide A. Cellular internalization of FnE elicits depression of mitochondrial function and consequent apoptosis that is strictly dependent on the activity of caspases 9 and 3. These findings describe the molecular details of a novel mechanism linking fibrin degradation to cell death in the placenta, which may also contribute to pathologic alterations in nonplacental vascular beds that are associated with fibrinolysis. PMID:19074731

Guo, Yi-He; Hernandez, Irene; Isermann, Berend; Kang, Tae-bong; Medved, Leonid; Sood, Rashmi; Kerschen, Edward J.; Holyst, Trudy; Mosesson, Michael W.

2009-01-01

236

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

PubMed Central

This research aimed to assess the toxicity of the pesticides abamectin 18 CE (0.02 g a.i. L-1), carbaryl 480 SC (1.73 g a.i. L-1), sulfur 800 GrDA (4.8 g a.i. L-1), fenitrothion 500 CE (0.75 g a.i. L-1), methidathion 400 CE (0.4 g a.i. L-1), and trichlorfon 500 SC (1.5 g a.i. L-1) as applied in integrated apple production in Brazil on the survival, oviposition capacity, and egg viability of the lacewing, Chrysoperla externa (Hagen) (Neuroptera: Chrysopidae) from Bento Gonçalves and Vacaria, Rio Grande do Sul State, Brazil. An attempt was made to study morphological changes caused by some of these chemicals, by means of ultrastructural analysis, using a scanning electronic microscope. Carbaryl, fenitrothion, and methidathion caused 100% adult mortality for both populations, avoiding evaluation of pesticides' effects on predator reproductive parameters. Abamectin and sulfur also affected the survival of these individuals with mortality rates of 10% and 6.7%, respectively, for adults from Bento Gonçalves, and were harmless to those from Vacaria at the end of evaluation. Trichlorfon was also harmless to adults from both populations. No compound reduced oviposition capacity. C. externa from Vacaria presented higher reproductive potential than those from Bento Gonçalves. In relation to egg viability, sulfur was the most damaging compound to both populations of C. externa. Ultrastructural analyses showed morphological changes in the micropyle and the chorion of eggs laid by C. externa treated with either abamectin or sulfur. The treatment may have influenced the fertilization of C. externa eggs and embryonic development. Sulfur was responsible for malformations in the end region of the abdomen and genitals of treated females. When applied to adults, abamectin, sulfur, and trichlorfon were harmless, while carbaryl, fenitrothion, and methidathion were harmful, according to the IOBC classification. PMID:20879916

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

2010-01-01

237

Enzymatic degradation of plutonium-contaminated cellulose products  

SciTech Connect

Enzyme solutions produced for commercial purposes unrelated to waste management have the potential for reducing the volume of wastes in streams containing cellulose, lipid and protein materials. For example, the authors have shown previously that cellulases used in denim production and in detergent formulations are able to digest cellulose-containing sorbents and other cellulose-based wastes contaminated either with crude oil or with uranium. This presentation describes the use of one such enzyme preparation (Rapidase{trademark}, manufactured by Genencor, Rochester, NY) for the degradation of cotton sorbents intentionally contaminated with low levels of plutonium. This is part of a feasibility study to determine if such treatments have a role in reducing the volume of low level and transuranic wastes to minimize the amount of radionuclide-contaminated waste destined for costly disposal options.

Heintz, C.E.; Rainwater, K.A.; Swift, L.M. [Texas Tech Univ., Lubbock, TX (United States); Barnes, D.L. [Amarillo National Resource Center for Plutonium, TX (United States); Worl, L.A. [Los Alamos National Lab., NM (United States)

1999-06-01

238

Toxicology of atmospheric degradation products of selected hydrochlorofluorocarbons  

NASA Technical Reports Server (NTRS)

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

Kaminsky, Laurence S.

1990-01-01

239

Enzymatic degradation of plutonium-contaminated cellulose products  

SciTech Connect

Enzyme solutions produced for commercial purposes unrelated to waste management have the potential for reducing the volume of wastes in streams containing cellulose, lipid and protein materials. For example, the authors have shown that cellulases used in denim production and in detergent formulations are able to digest cellulose-containing sorbents and other cellulose-based wastes contaminated either with crude oil or with radionuclides. This presentation describes the use of one such enzyme preparation (Rapidase{trademark}) for the degradation of cotton sorbents intentionally contaminated with low levels of plutonium. This is part of a feasibility study to determine if such treatments have a role in reducing the volume of low level and transuranic wastes to minimize the amount of radionuclide-contaminated waste that must be disposed of in secured storage areas.

Heintz, C.E.; Rainwater, K.A.; Swift, L.M. [Texas Tech Univ., Lubbock, TX (United States); Barnes, D.L. [Amarillo National Resource Center for Plutonium, TX (United States); Worl, L.; Avens, L. [Los Alamos National Lab., NM (United States)

1999-03-01

240

Production of degradable polymers from food-waste streams  

SciTech Connect

In the United States, billions of pounds of cheese whey permeate and approximately 10 billion pounds of potatoes processed each year are typically discarded or sold as cattle feed at $3{endash}6/ton; moreover, the transportation required for these means of disposal can be expensive. As a potential solution to this economic and environmental problem, Argonne National Laboratory is developing technology that: Biologically converts existing food-processing waste streams into lactic acid and uses lactic acid for making environmentally safe, degradable polylactic acid (PLA) and modified PLA plastics and coatings. An Argonne process for biologically converting high-carbohydrate food waste will not only help to solve a waste problem for the food industry, but will also save energy and be economically attractive. Although the initial substrate for Argonne's process development is potato by-product, the process can be adapted to convert other food wastes, as well as corn starch, to lactic acid. Proprietary technology for biologically converting greater than 90% of the starch in potato wastes to glucose has been developed. Glucose and other products of starch hydrolysis are subsequently fermented by bacteria that produce lactic acid. The lactic acid is recovered, concentrated, and further purified to a polymer-grade product.

Tsai, S.P.: Coleman, R.D.; Bonsignore, P.V.; Moon, S.H.

1992-01-01

241

Production of degradable polymers from food-waste streams  

SciTech Connect

In the United States, billions of pounds of cheese whey permeate and approximately 10 billion pounds of potatoes processed each year are typically discarded or sold as cattle feed at $3{endash}6/ton; moreover, the transportation required for these means of disposal can be expensive. As a potential solution to this economic and environmental problem, Argonne National Laboratory is developing technology that: Biologically converts existing food-processing waste streams into lactic acid and uses lactic acid for making environmentally safe, degradable polylactic acid (PLA) and modified PLA plastics and coatings. An Argonne process for biologically converting high-carbohydrate food waste will not only help to solve a waste problem for the food industry, but will also save energy and be economically attractive. Although the initial substrate for Argonne`s process development is potato by-product, the process can be adapted to convert other food wastes, as well as corn starch, to lactic acid. Proprietary technology for biologically converting greater than 90% of the starch in potato wastes to glucose has been developed. Glucose and other products of starch hydrolysis are subsequently fermented by bacteria that produce lactic acid. The lactic acid is recovered, concentrated, and further purified to a polymer-grade product.

Tsai, S.P.: Coleman, R.D.; Bonsignore, P.V.; Moon, S.H.

1992-07-01

242

Anaerobic degradation of renewable biomass for production of methane  

SciTech Connect

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.

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

1996-12-31

243

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

PubMed Central

Toxoflavin (an azapteridine) is degraded to a single product by toxoflavin lyase (TflA) in a reaction dependent on reductant, Mn(II), and oxygen. The isolated product was fully characterized by NMR and MS and was identified as a triazine in which the pyrimidine ring was oxidatively degraded. A mechanism for toxoflavin degradation based on the identification of the enzymatic product and the recently determined crystal structure of toxoflavin lyase is proposed. PMID:22304755

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

2012-01-01

244

Removal of Fission Products and Their Complexing Agents from Degraded Solvent by Ion Exchange Method  

Microsoft Academic Search

Removal of fission products and their complexing agents from chemically degraded TBP\\/kerosene and particularly from the kerosene diluent, was studied. With the use of column technique with mixed anion and cation exchange resins, more than 80% of the fission products and their complexing agents were removed. The carboxylic acids, which constitute one of the degradation products bringing about decrease of

Ken OHWADA

1967-01-01

245

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

Technology Transfer Automated Retrieval System (TEKTRAN)

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 potential risk of pesticides to aquatic environments, were calculat...

246

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

PubMed Central

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

Lesmes-Fabian, Camilo; Binder, Claudia R.

2013-01-01

247

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

PubMed

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

Lesmes-Fabian, Camilo; Binder, Claudia R

2013-04-01

248

Premature Translational Termination Products Are Rapidly Degraded Substrates for MHC Class I  

E-print Network

of America Abstract Nearly thirty percent of all newly synthesized polypeptides are targeted for rapid proteasome-mediated degradation. These rapidly degraded polypeptides (RDPs) are a source of antigenic rapidly degraded. To study the cellular fate of premature termination products, we used the antibiotic

Nicchitta, Chris

249

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

Microsoft Academic Search

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

S. Fadda; G. Vignolo; G. Oliver

2001-01-01

250

Reliability assessment for product with Wiener process degradation based on marker data  

Microsoft Academic Search

Reliability assessment method based on performance degradation data has been proven to be useful when dealing with products characterized as long-life and highly reliable. However, this method can hardly be applied when measurement of performance degradation is technically difficult or costly. To tackle this problem, this paper proposes to utilize the measurement data which are related to the performance degradation,

B. H. Peng; J. L. Zhou

2010-01-01

251

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

PubMed

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

Skrbi?, B; Predojevi?, Z

2008-05-01

252

Pyrene degradation accelerated by constructed consortium of bacterium and microalga: effects of degradation products on the microalgal growth.  

PubMed

Abundant microbes including bacteria, fungi, or algae are capable of biodegrading polycyclic hydrocarbons (PAHs). However, pure cultures never occur in the contaminated environments. This study aimed to understand the general potential mechanisms of interactions between microbes under pollution stress by constructing a consortium of PAH-degrading microalga (Selenastrum capricornutum) and bacterium (Mycobacterium sp. strain A1-PYR). Bacteria alone could grow on the pyrene, whereas the growth of algae alone was substantially inhibited by the pyrene of 10 mg L(-1). In the mixing culture of algae and bacteria, the growth rate of algae was significantly increased from day 4 onward. Rapid bacterial degradation of pyrene might mitigate the toxicity of pyrene to algae. Phenolic acids, the bacterial degradation products of pyrene, could serve as the phytohormone for promoting algal growth in the coculture of algae and bacteria. In turn, bacterial growth was also enhanced by the algae presented in the mixing culture. Consequently, the fastest degradation of pyrene among all biodegradation systems was achieved by the consortium of algae and bacteria probably due to such interactions between the two species by virtue of degradation products. This study reveals that the consortium containing multiple microbial species is high potential for microbial remediation of pyrene-contaminated environments, and provides a new strategy to degrade the recalcitrant PAHs. PMID:25382552

Luo, Shusheng; Chen, Baowei; Lin, Li; Wang, Xiaowei; Tam, Nora Fung-Yee; Luan, Tiangang

2014-12-01

253

Embryotoxicity of the alkylphenol degradation product 4-nonylphenol to the crustacean Daphnia magna.  

PubMed Central

Laboratory studies have suggested that some alkylphenols and pesticides elicit developmental toxicity to crustaceans. The purpose of the present study was to evaluate the possibility that the alkylphenol degradation product 4-nonylphenol is embryotoxic to the crustacean Daphnia magna through its known ability to interfere with the metabolic elimination of testosterone. Direct exposure of maternal daphnids to testosterone caused developmental abnormalities in neonates that consisted of partial arrest of early embryonic development and abnormalities in shell spine and first antennae development. Exposure of maternal daphnids to concentrations of 4-nonylphenol also produced developmental abnormalities though the profile of abnormalities was distinct from that observed throughout the testosterone concentration-response curve. Thus, 4-nonylphenol is a developmental toxicant in daphnids, but its toxicity is not consistent with that elicited by elevated testosterone accumulation. Further experiments demonstrated that testosterone was directly toxic to developing embryos, and the maternal organism can serve as the vector for this toxicity. In contrast, neither direct embryo exposure nor early maternal exposure to 4-nonylphenol elicited embryotoxicity consistent with that observed during continuous maternal and gestational exposure. Thus, 4-nonylphenol is not directly embryotoxic at these exposure levels, but rather toxicity is mediated by maternal influences during gestation. The threshold concentration for the occurrence of developmental abnormalities ( approximately 44 microg/L) indicates that typical environmental concentrations of 4-nonylphenol pose no imminent hazard with respect to developmental toxicity. However, these effects do occur at sufficiently low levels to warrant evaluation of the relative susceptibility of other crustacean species to this previously uncharacterized mode of toxicity. PMID:11133392

LeBlanc, G A; Mu, X; Rider, C V

2000-01-01

254

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

PubMed

The objective of this study was to characterize concentrations of atrazine, terbuthylazine, and other pesticides in amphibian habitats in surface waters of a corn-production area of the western Highveld region (North-West Province) of South Africa. The study was conducted from November 2001 to June 2002, coinciding with the corn-production season. Pesticide residues were measured at regular intervals in surface water from eight ponds, three in a non-corn-growing area (NCGA) and five within the corn-growing area (CGA). Measured atrazine concentrations differed significantly among sites and between samples. In the five CGA sites, the maximum atrazine concentrations measured during the study ranged from 1.2 to 9.3 microg/L. Although no atrazine was recorded as being applied in the catchment of the three NCGA sites, maximum concentrations from 0.39 to 0.84 microg/L were measured during the study, possibly as a result of atmospheric transport. Maximum measured concentrations of terbuthylazine ranged from 1.22 to 2.1 microg/L in the NCGA sites and from 1.04 to 4.1 microg/L in the CGA sites. The source of terbuthylazine in the NCGA sites may have been in use other than in corn. The triazine degradation products, deisopropylatrazine (DIA) and deethylatrazine (DEA) and diaminochlorotriazine (DACT) were also found in water from both the CGA and NCGA sites. Concentrations of DIA were > or = 1 microg/L throughout the season, while DEA concentrations were mostly <0.5 microg/L before planting but increased after planting and application of herbicides to concentrations >2 microg/L in some locations. Concentrations of DACT were highly variable (LOD to 8 microg/L) both before and after planting and application, suggesting that they resulted from historical use of triazines in the area. Other herbicides such as simazine and acetochlor were only detected infrequently and pesticides such as S-metolachlor, cypermethrin, monocrotophos, and terbuphos, known to be used in the CGA, were not detected in any of the samples. Because of dilution by higher than normal rainfall in the study period, these concentrations may not be predictive of those in years of normal rainfall. PMID:15701400

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

2005-05-01

255

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

USGS Publications Warehouse

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

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

2005-01-01

256

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

NASA Astrophysics Data System (ADS)

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.

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

2012-04-01

257

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

USGS Publications Warehouse

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

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

2001-01-01

258

Fate of seven pesticides in an aerobic aquifer studied in column experiments.  

PubMed

The fate of selected pesticides (bentazone, isoproturon, DNOC, MCPP, dichlorprop and 2,4-D) and a metabolite (2,6-dichlorobenzamide (BAM)) was investigated under aerobic conditions in column experiments using aquifer material and low concentrations of pesticides (approximately 25 microg/l). A solute transport model accounting for kinetic sorption and degradation was used to estimate sorption and degradation parameters. Isoproturon and DNOC were significantly retarded by sorption, whereas the retardation of the phenoxy acids (MCPP, 2,4-D and dichlorprop), BAM and bentazone was very low. After lag periods of 16-33 days for the phenoxy acids and 80 days for DNOC, these pesticides were degraded quickly with 0.-order rate constants of 1.3-2.6 microg/l/day. None of the most probable degradation products were detected. PMID:11057587

Tuxen, N; Tüchsen, P L; Rügge, K; Albrechtsen, H J; Bjerg, P L

2000-11-01

259

Planning and Managing Pesticide Stores  

E-print Network

products* (Defra, 2006), the Code of practice for suppliers of pesticides to agriculture, horticulture Council) specialises in training related to agricultural and other land-based activities. Although it does in the foundation module PA1: Certificate of competence in the safe use of pesticides and in other pesticide

260

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

Federal Register 2010, 2011, 2012, 2013, 2014

...www.epa.gov/dockets. FOR FURTHER INFORMATION CONTACT: Vera Au, Field and External Affairs Division, Office of Pesticide...308-9069; fax number: (703) 305-5884; email address: au.vera@epa.gov. SUPPLEMENTARY INFORMATION: I. Executive...

2013-01-18

261

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

Federal Register 2010, 2011, 2012, 2013, 2014

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

2011-07-13

262

Degradation and monitoring of acetamiprid, thiabendazole and their transformation products in an agro-food industry effluent during solar photo-Fenton treatment in a raceway pond reactor.  

PubMed

In this study, pesticides acetamiprid and thiabendazole and their transformation products (TPs), seven from each pesticide, were successfully monitored during solar photo-Fenton treatment in a real secondary effluent from an agro-food industry spiked with 100?gL(-1) of each pesticide. To this end, a highly sensitive procedure was developed, based on liquid chromatography (LC) coupled to hybrid quadrupole-linear ion trap mass spectrometry (QqLIT-MS). In addition, finding low-cost and operational technology for the application of AOPs would then facilitate their use on a commercial level. Simple and extensive photoreactors such as raceway pond reactors (RPRs) are therefore proposed as an alternative for the application of solar photo-Fenton. Results showed that high degradation could be achieved in a complex water matrix (>99% TBZ and 91% ACTM in 240min) using a 120-L RPR pilot plant as novel technology. The analyses indicated that after the treatment only three TPs from ACTM were still present in the effluent, while the others had been removed. The study showed that the goal of either just removing the parent compounds, or going one step further and removing all the TPs, can significantly change the treatment time, which would affect process costs. PMID:25841181

Carra, Irene; Sirtori, Carla; Ponce-Robles, Laura; Sánchez Pérez, José Antonio; Malato, Sixto; Agüera, Ana

2015-07-01

263

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

NASA Astrophysics Data System (ADS)

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.

Bilal Butt, S.; Qureshi, Rashid Nazir

2008-06-01

264

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

USGS Publications Warehouse

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

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

1991-01-01

265

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

PubMed

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

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

2011-09-15

266

Agricultural Pesticides and Selected Degradation Products in Five Tidal Regions and the Mainstem of Chesapeake Bay  

Technology Transfer Automated Retrieval System (TEKTRAN)

Nutrients, sediment, air pollution, and toxics from the water sources and the surrounding airshed are major problems contributing to poor water quality in many regions of the Chesapeake Bay (CB). Toxics are defined as chemicals that may affect the reproduction, development, and ultimately, the surv...

267

Identification of transformation products of pesticides and veterinary drugs in food and related matrices: Use of retrospective analysis.  

PubMed

Retrospective analysis has been applied in different samples, including honey, meat, feed and nutraceutical products from ginkgo biloba, soya, royal jelly and green tea, with the aim of searching transformation products of pesticides and veterinary drugs, which were not included in an initial analysis. Generic extraction and analytical procedures based on high resolution mass spectrometry (Exactive-Orbitrap analyser was used) have been applied. All obtained data have been reprocessed and some compounds as anhydroerythromycin in honey and 3,5,6-trichloro-2-pyridinol in feed have been detected, demonstrating the applicability and the utility of the procedure. Advantages and disadvantages of retrospective approach have been highlighted. PMID:25748536

Gómez-Pérez, María Luz; Romero-González, Roberto; Vidal, José Luis Martínez; Frenich, Antonia Garrido

2015-04-10

268

Solid state compatibility study and characterization of a novel degradation product of tacrolimus in formulation.  

PubMed

Tacrolimus is macrolide drug that is widely used as a potent immunosuppressant. In the present work compatibility testing was conducted on physical mixtures of tacrolimus with excipients and on compatibility mixtures prepared by the simulation of manufacturing process used for the final drug product preparation. Increase in one major degradation product was detected in the presence of magnesium stearate based upon UHPLC analysis. The degradation product was isolated by preparative HPLC and its structure was elucidated by NMR and MS studies. Mechanism of the formation of this degradation product is proposed based on complementary degradation studies in a solution and structural elucidation data. The structure was proven to be alpha-hydroxy acid which is formed from the parent tacrolimus molecule through a benzilic acid type rearrangement reaction in the presence of divalent metallic cations. Degradation is facilitated at higher pH values. PMID:25804434

Rozman Peterka, Tanja; Grahek, Rok; Hren, Jure; Bastarda, Andrej; Bergles, Jure; Urleb, Uroš

2015-06-10

269

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

PubMed Central

Background: The dried and steamed roots of Rehmannia glutinosa have different pharmacological functions and indications. Catalpol, the main active component of the dried root, was found to be entirely degraded together with amino acids and some oligosaccharides during preparation of the steamed root. Its degradation may contribute to the differences between dried and steamed roots. Objective: To reveal the characteristics and kinetics of catalpol degradation, and evaluate its influence on the antioxidant properties of steamed Rehmannia roots. Materials and Methods: Purified catalpol was heated under different pH and temperature values for different times, alone or with sugars or amino acids. Catalpol concentration was determined by high-performance liquid chromatography. Browning was expressed by the absorbance at 420 nm (A420), and antioxidation was displayed by 2,2-diphenyl-1-picrylhydrazyl free radical scavenging ability (SADPPH). Activation energy was calculated using Arrhenius plotting. Results: Catalpol was stable in neutral conditions and sensitive to acidic pH under high temperatures. Sugars had no influence on catalpol degradation; however, most amino acids, except for proline, could promote the degradation, and were associated with an increase in A420 and SADPPH values. These changes were proved to be mainly related with catalpol aglycone and were dependent on the presence of amino acids. Catalpol degradation was found to obey first-order kinetics. The activation energies were 81.7, 88.8 and 98.7 kJ/mol at pH 4.0, 5.0, and 6.0 respectively, and 70.7 kJ/mol at pH 4.0 value and in the presence of glycine. Conclusions: Catalpol degradation, especially, in the presence of amino acids can substantially boost antioxidant properties of the products; therefore, the traditional method for processing Rehmannia root seems rather apt. PMID:24914291

Wei, Guo-dong; Wen, Xue-sen

2014-01-01

270

Assessment of heavy metal and pesticide levels in soil and plant products from agricultural area of Belgrade, Serbia.  

PubMed

This study was aimed to assess the levels of selected heavy metals and pesticides in soil and plant products from an agricultural area of Belgrade, Serbia and to indicate possible sources and risks of contamination. Soil, vegetable, and fruit samples from the most important agricultural city areas were collected from July to November of 2006. Metal contents were determined by atomic absorption spectrometry, whereas pesticide residues were analyzed by gas chromatography-mass spectrometry after extraction performed using solid-phase microextraction technique. Soil characterization based on the determination of selected physical and chemical properties revealed heterogeneous soils belonging to different soil groups. The concentrations of lead, cadmium, copper, and zinc in soil samples do not exceed the limits established by national and international regulations. Residues of the herbicide atrazine were detected in three soil samples, with levels lower than the relevant limit. The presence of other herbicides, namely prometryn, chloridazon, acetochlor, flurochloridone, and napropamide, was registered in some soil samples as well. Among the insecticides investigated in the soil, fenitrothion and chlorpyrifos were the only ones detected. In most of the investigated vegetable samples from the Obrenovac area, Pb and Cd contents are higher in comparison with the maximum levels, indicating the emission of coal combustion products from local thermal power plants as a possible source of contamination. Residue levels of some herbicides and insecticides (metribuzin, trifluralin, pendimethalin, bifenthrin, chlorpyrifos, and cypermethrin) determined in tomato, pepper, potato, and onion samples from Slanci, Ovca, and Obrenovac areas are even several times higher than the maximum residue levels. Inappropriate use of these plant protection products is considered to be the most probable reason of contamination. Because increased levels of heavy metals and pesticide residues found in plant products could pose a risk to consumers' health, their continual monitoring before product distribution to city markets is indispensable. PMID:19603130

Markovi?, Mirjana; Cupa?, Svjetlana; Durovi?, Rada; Milinovi?, Jelena; Kljaji?, Petar

2010-02-01

271

Quantitative determination of catecholic degradation products from insect sclerotized cuticles.  

PubMed

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

Andersen, Svend Olav

2008-09-01

272

Photochemical degradation of ciprofloxacin in UV and UV/H?O? process: kinetics, parameters, and products.  

PubMed

Photochemical degradation of fluoroquinolone ciprofloxacin (CIP) in water by UV and UV/H?O? were investigated. The degradation rate of CIP was affected by pH, H?O? dosage, as well as the presence of other inorganic components. The optimized pH value and H?O? concentration were 7.0 and 5 mM. Carbonate and nitrate both impeded CIP degradation. According to liquid chromatography-tandem mass spectrometry analysis, four and 16 products were identified in UV and UV/H?O? system, respectively. Proposed degradation pathways suggest that reactions including the piperazinyl substituent, quinolone moiety, and cyclopropyl group lead to the photochemical degradation of CIP. Toxicity of products assessed by Vibrio qinghaiensis demonstrated that UV/H?O? process was more capable on controlling the toxicity of intermediates in CIP degradation than UV process. PMID:23054793

Guo, Hong-Guang; Gao, Nai-Yun; Chu, Wen-Hai; Li, Lei; Zhang, Yong-Ji; Gu, Jin-Shan; Gu, Yu-Liang

2013-05-01

273

The white-rot fungus Phanerochaete chrysosporium : conditions for the production of lignin-degrading enzymes  

Microsoft Academic Search

Investigating optimal conditions for lignin-degrading peroxidases production by Phanerochaete chrysosporium (P. chrysosporium) has been a topic for numerous researches. The capability of P. chrysosporium for producing lignin peroxidases (LiPs) and manganese peroxidases (MnPs) makes it a model organism of lignin-degrading enzymes\\u000a production. Focusing on compiling and identifying the factors that affect LiP and MnP production by P. chrysosporium, this critical

Deepak Singh; Shulin Chen

2008-01-01

274

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

SciTech Connect

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

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

1988-01-15

275

Photochemical Attenuation of Pesticides in Prairie Potholes  

NASA Astrophysics Data System (ADS)

Prairie potholes are small, shallow, glacially-derived wetlands scattered across a vast region extending from Midwestern United States into south central Canada known as the Prairie Pothole Region (PPR). They constitute one of the largest inland wetland systems on Earth and play a prominent role in sustaining the regional biodiversity and productivity. Throughout the PPR, historic and contemporary conversion of native prairie for agriculture resulted in a pronounced loss of potholes. Remaining potholes have become interspersed within a matrix of agricultural landscape and trap nonpoint source pollutants such as pesticides from adjacent farmland, which has raised concerns regarding negative impacts on the water quality of downstream water bodies. The fate and persistence of pesticides in potholes, however, remains largely unexplored. Prairie potholes are typically characterized by shallow depth (i.e., large photic zone) and high levels of dissolved organic matter (DOM), making them ideal for photochemical reactions. In this context, we collected pothole water samples from North Dakota to investigate the rates and mechanisms of sunlight-induced attenuation of pesticides. The photodegradation kinetics and pathways of sixteen pesticides in the pothole water were monitored under both simulated and natural sunlight. For most pesticides, photolysis accelerated in the pothole water relative to the buffer control, which pointed to the importance of photosensitized processes (i.e., indirect photolysis). Upon solar irradiation, a mixture of photochemically produced reactive intermediates (PPRIs), such as carbonate radical, hydroxyl radical, singlet oxygen, and triplet-excited state DOM, formed in the pothole water. The major pathways through which pesticides degraded were inferred from the relative contribution attributable to specific PPRIs via quencher experiments. Different classes of pesticides exhibited contrasting photochemical behavior, but singlet oxygen and triplet DOM appeared to exert the largest effects on the overall photodegradation. Furthermore, a suite of second-order rate constants for reactions of pesticides with PPRIs were derived based on the quenching effect on observed reaction rate constants and measured steady-state concentrations of PPRIs. These rate constants may find practical utility for estimating DOM photochemical reaction rates in addition to data traditionally estimated from model compounds. Overall, our work contributed to a systematic evaluation of the potential for photochemical attenuation of pesticides in near-surface pothole water. Given recent incentives to expand agriculture in the PPR for production of organic crops and corn-based biofuels, this research also calls for the need to properly conserve prairie potholes and to develop regionally-specific, sustainable water resource management and land use strategies.

Zeng, T.; Arnold, W. A.

2013-12-01

276

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

EPA Science Inventory

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

277

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

PubMed Central

Background Clobazam is used for the treatment of different types of seizure and epilepsy. The present research is undertaken to study the systematic forced degradation of clobazam and to identify its main degradation product under basic conditions. Methods The degradation of clobazam was studied under different conditions. Clobazam and its degradation products were separated using a Nova-Pak C18 column and a mixture of KH2PO4 50 mM (pH 8.5) and acetonitrile (50:50, v/v) as the mobile phase with UV detection at 230 nm. Results The within-day and between-day precision values in the calibration range of 0.1-20 ?g/ml were within 0.5-1.5%. Clobazam was relatively stable in solid from under exposure to visible and UV light and also heat. The clobazam aqueous solution of clobazam was more labile under exposure to visible and UV light. The bulk drug was significantly degraded under exposure to 2 M HCl, 0.1 M NaOH or 3% H2O2. Using the tablet powder, higher degradation rates were observed under different stress conditions. The main degradation product of clobazam under basic condition was subsequently characterized. Conclusion The developed method could be used for the determination of clobazam in the presence of its degradation products with acceptable precision and accuracy. The applicability of the proposed method was evaluated in commercial dosage forms analysis. PMID:24919821

2014-01-01

278

Oxidation of pesticides by in situ electrogenerated hydrogen peroxide: study for the degradation of 2,4-dichlorophenoxyacetic acid.  

PubMed

This paper reports an investigation on the performance of the H2O2 electrogeneration process on a rotating RVC cylinder cathode, and the optimization of the O2 reduction rate relative to cell potential. A study for the simultaneous oxidation of the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) by the in situ electrogenerated H2O2 is also reported. Experiments were performed in 0.3 M of K2SO4, pH of 10 and 3.5. Oxygen concentration in solution was kept in 25 mg L(-1). Maximum hydrogen peroxide generation rate was reached at -1.6 V versus SCE for both, acidic and alkaline solutions. Then, 100 mg L(-1) of 2,4-D was added to the solution. First order apparent rate constants for 2,4-D degradation ranged from 0.9 to 6.3x10(-5) m s(-1), depending on the catalyst used (UV or UV+Fe(II)). TOC reduction was favored in acidic medium where a decreasing of 69% of the initial concentration was observed in the process catalyzed by UV+Fe(II). This figure was an indication that some of the intermediates derived from 2,4-D decomposition remained in solution, mainly as lighter aliphatic compounds. PMID:16707213

Badellino, Carla; Rodrigues, Christiane Arruda; Bertazzoli, Rodnei

2006-09-21

279

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

PubMed

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

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

2013-09-15

280

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...

281

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

Microsoft Academic Search

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

J Kammerbauer; J Moncada

1998-01-01

282

Can co-culturing of two white-rot fungi increase lignin degradation and the production of lignin-degrading enzymes?  

Microsoft Academic Search

The aim of this work was to investigate the poorly understood effects of co-culturing of two white rot fungi on the production of lignin-degrading enzyme activities. Four species, Ceriporiopsis subvermispora, Physisporinus rivulosus, Phanerochaete chrysosporium and Pleurotus ostreatus were cultured in pairs to study the degradation of aspen wood and the production of lignin-degrading enzymes. Potential of co-culturing for biopulping was

Yujie Chi; Annele Hatakka; Pekka Maijala

2007-01-01

283

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

USGS Publications Warehouse

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

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

2003-01-01

284

Radiolytic degradation of malathion and lindane in aqueous solutions  

NASA Astrophysics Data System (ADS)

Degradation of malathion and lindane pesticides present in an aqueous solution was investigated on a laboratory scale upon gamma-irradiation from a 60Co source. The effects of pesticide group, presence of various additives and absorbed dose on efficiency of pesticide degradation were investigated. Gamma-irradiation was carried out in distilled water solutions (malathion and lindane) and in combination with humic solution (HS), nitrous oxide (N 2O) and HS/N 2O (lindane) over the range 0.1-2 kGy (malathion) and 5-30 kGy (lindane). Malathion was easily degraded at low absorbed doses compared to lindane in distilled water solutions. Absorbed doses required to remove 50% and 90% of initial malathion and lindane concentrations in distilled water solutions were 0.53 and 1.77 kGy (malathion) and 17.97 and 28.79 kGy (lindane), respectively. The presence of HS, N 2O and HS/N 2O additives in aqueous solutions, significantly improved the effectiveness of radiolytic degradation of lindane. Chemical analysis of the pesticides and the by-products resulted from the radiolytic degradation were made using a gas chromatography associated with mass spectrometry (GC-MS). Additionally, the final degradation products of irradiation as detected by ion chromatography (IC) were acetic acid and traces of some anions (phosphate and chloride).

Mohamed, K. A.; Basfar, A. A.; Al-Kahtani, H. A.; Al-Hamad, K. S.

2009-11-01

285

21 CFR 864.7320 - Fibrinogen/fibrin degradation products assay.  

Code of Federal Regulations, 2010 CFR

... FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Hematology Kits and Packages § 864.7320 Fibrinogen/fibrin degradation products assay. (a)...

2010-04-01

286

21 CFR 864.7320 - Fibrinogen/fibrin degradation products assay.  

Code of Federal Regulations, 2011 CFR

... FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Hematology Kits and Packages § 864.7320 Fibrinogen/fibrin degradation products assay. (a)...

2011-04-01

287

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-...

288

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

E-print Network

Cellular RNA levels are determined by the interplay of RNA production, processing and degradation. However, because most studies of RNA regulation do not distinguish the separate contributions of these processes, little ...

Rabani, Michal

289

Soil column leaching of pesticides.  

PubMed

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

Katagi, Toshiyuki

2013-01-01

290

The expanding role of LCMS in analyzing metabolites and degradation products of food contaminants  

Microsoft Academic Search

Liquid chromatography-mass spectrometry (LC-MS) has contributed significantly in advancing research in the analysis of metabolites and degradation products of food contaminants. Of particular interest is the comprehensive application of LC-MS to discovery of degradation products and metabolites. This review, covering research published between 2003 and 2008, describes how LC-MS has been used in this field, with the majority of work

Damià Barceló

2008-01-01

291

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

Microsoft Academic Search

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

Glenn W. Stratton

1984-01-01

292

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

SciTech Connect

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

Pugh, K.C.

1994-10-01

293

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

Microsoft Academic Search

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),

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

2005-01-01

294

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

USGS Publications Warehouse

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

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

2001-01-01

295

Procyanidins modify insulinemia by affecting insulin production and degradation.  

PubMed

Previous studies from our research group have suggested that procyanidins modify glycemia and insulinemia. The aim of this work was to evaluate the effects of procyanidins on ?-cell functionality in a nonpathological system. Four groups of healthy rats were studied. The animals were given daily acute doses of grape seed procyanidin extract (GSPE) for different time periods and at different daily amounts. A ?-cell line (INS-1E) was treated with 25 mg GSPE/L for 24 h to identify possible mechanisms of action for the procyanidins. In vivo experiments showed that different doses of GSPE affected insulinemia in different ways by modifying ?-cell functionality and/or insulin degradation. The islets isolated from rats that were treated with 25 mg GSPE/kg of body weight for 45 days exhibited a limited response to glucose stimulation. In addition, insulin gene expression, insulin synthesis and expression of genes related to insulin secretion were all down-regulated. In vitro studies revealed that GSPE decreased the ability of ?-cells to secrete insulin in response to glucose. GSPE increased glucose uptake in ?-cells under high-glucose conditions but impaired glucose-induced mitochondrial hyperpolarization, decreased adenosine triphosphate (ATP) synthesis and altered cellular membrane potentials. GSPE also modified Glut2, glucokinase and Ucp2 gene expression as well as altered the expression of hepatic insulin-degrading enzyme (Ide), thereby altering insulin degradation. At some doses, procyanidins changed ?-cell functionality by modifying insulin synthesis, secretion and degradation under nonpathological conditions. Membrane potentials and Ide provide putative targets for procyanidins to induce these effects. PMID:22444499

Castell-Auví, Anna; Cedó, Lídia; Pallarès, Victor; Blay, M Teresa; Pinent, Montserrat; Motilva, M José; Garcia-Vallvé, Santiago; Pujadas, Gerard; Maechler, Pierre; Ardévol, Anna

2012-12-01

296

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

PubMed

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

Sukkhum, Sukhumaporn; Tokuyama, Shinji; Kitpreechavanich, Vichien

2012-01-01

297

Fungal degradation of coal as a pretreatment for methane production  

USGS Publications Warehouse

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.

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

2013-01-01

298

Ozonation of metoprolol in aqueous solution: ozonation by-products and mechanisms of degradation.  

PubMed

This study investigated the degradation pathway of metoprolol, a widely used ?-blocker, in the ozonation via the identification of generated ozonation by-products (OPs). Structure elucidation of OPs was performed using HPLC coupled with quadrupole time-of-flight high-resolution mass spectrometry. Seven OPs were identified, and four of these have not been reported elsewhere. Identified OPs of metoprolol included aromatic ring breakdown by-products; aliphatic chain degraded by-products and aromatic ring mono-, di-, and tetrahydroxylated derivatives. Based on the detected OPs, metoprolol could be degraded through aromatic ring opening reaction via reaction with ozone (O3) and degradation of aliphatic chain and aromatic ring via reaction with hydroxyl radical (•OH). PMID:23054788

Tay, Kheng Soo; Rahman, Noorsaadah Abd; Abas, Mhd Radzi Bin

2013-05-01

299

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

PubMed

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

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

2014-07-01

300

Non-Aqueous Electromigration Analysis of Some Degradation Products of Carvedilol  

PubMed Central

A capillary electrophoresis method was used for assay of some degradation products of carvedilol. The optimized parameters were as; running buffer 80 mM acetate dissolved in methanol/ethanol mixture (65:35% v/v), applied voltage of 19 kV, temperature is 20 ºC and the wavelength range of 200-350 nm. The results indicate that the proposed capillary electrophoresis method could effectively separate carvedilol from its degradation products and can be employed as a stability indicating assay method. In addition, the presence of a new unknown degradation product was discovered by this method. In addition, capillary electrophoresis behaviour of carvedilol in photo/force degradation conditions gave valuable information concerning the dissimilarities of their ionization. Results indicated that the capillary electrophoresis proposed method can be used for the determination of carvedilol in human serum. Finally, accuracy of the proposed method was established by recovery experiments from spiked human serum samples. PMID:25237342

Jouyban, Abolghasem; Hasanzadeh, Mohammad; Shadjou, Nasrin

2014-01-01

301

Degradation of chlorfenvinphos in carrots during storage  

Microsoft Academic Search

In order to investigate the degradation products of chlorfenvinphos, organically grown carrots were treated with the pesticide. After storage at 5 °C for 3 months, the following compounds were detected by gas chromatography-mass spectrometric (GC-MS) analysis: 1-(2?,4?-dichlorophenyl)ethan-1-ol, 2,4-dichlorobenzoic acid, and 2,2-dichloro-1-(2?,4?-dichlorophenyl) vinyl alcohol. The metabolic fate of the pesticide was also investigated by use of 14C-ring-labelled chlorfenvinphos which was prepared

U. Uygun

1997-01-01

302

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

PubMed

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

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

303

Electrochemical biosensors for rapid determination of pesticide residues in agricultural products  

NASA Astrophysics Data System (ADS)

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

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

2005-11-01

304

MONITORING AND MODELLING OF RADIOLYTIC DEGRADATION PRODUCTS OF TBP/n-DODECANE  

SciTech Connect

The Plutonium Uranium Extraction (PUREX) solvent system was developed for the separation of plutonium and uranium from irradiated fuel. Since the implementation of this process, the degradation chemistry associated with the irradiated solvent system, tributyl phosphate (TBP)/n-dodecane/nitric acid has been extensively studied as the integrity of the organic solvent is paramount for reproducible performance of the separation flowsheet (extraction/scrub/strip) during multiple cycles. In PUREX-like processes, the extent of decomposition is dependent not only upon the solvent, but also upon the presence of constituents, such as nitric acid, that interact with TBP and increase its susceptibility to radiolytic degradation. The build-up of degradation products in the organic phase alters process flowsheet performance via modification of the metal ions speciation, loss of solvent components, and enhanced water transport into the organic phase. On-line identification and quantification of the solvent degradation products would provide the necessary information for more detailed process control as well as providing the basis for timing solvent washing or replacement. In our research, we are exploring the potential of on-line monitoring for the PUREX solvent radiolytic degradation products. To identify degradation products, TBP/n-dodecane solvent, contacted with aqueous nitric acid solutions of variable concentrations are subjected to various gamma radiation external doses then analyzed by electro-spray ionization mass spectrometry (ESMS). In addition, vibrational spectroscopy is utilized to monitor and quantify major degradation products including dibutyl phosphoric acid (HDBP) and monobutyl phosphoric acid (H2MBP) in TBP/n-dodecane solvent. The compiled spectroscopic databases serve for developing interpretive and predictive chemometric models for the quantification of the PUREX solvent degradation products.

Peterson, James M.; Levitskaia, Tatiana G.; Bryan, Samuel A.

2011-10-03

305

Application of Current Hapten in the Production of Broad Specificity Antibodies Against Organophosphorus Pesticides  

Microsoft Academic Search

Diethylphosphono acetic acid (DPA) was used as a current hapten to generate broad specificity polycolonal antibodies against a group of organophosphorus pesticides. Six New Zealand white rabbits were immunized with immunogens synthesized by the active ester method (AEM) or 1-ethyl-3-(3-dimethylaminopropyl)-carbodimide method (EDC). The titers of antisera reached 25 600 by AEM and 6 400 by EDC, respectively. Polyclonal antibodies raised

LIU Xian-jin; YAN Chun-rong; LIU Yuan; YU Xiang-yang; ZHANG Cun-zheng

2008-01-01

306

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

PubMed Central

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

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

2014-01-01

307

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

PubMed Central

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

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

308

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

NASA Astrophysics Data System (ADS)

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

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

2006-01-01

309

Pesticides and Other Chemicals: Minimizing Worker Exposures  

Microsoft Academic Search

Pesticides, ammonia, and sanitizers, all used in agricultural production present ongoing risks for exposed workers. Pesticides continue to poison workers despite elimination of some of the most toxic older products. Obligatory reporting of pesticide poisonings exists in 30 states and surveillance of poisoning occurs in only 12. Estimates of poisoning numbers have been based on sampling but funding for this

Matthew Keifer; Frank Gasperini; Mark Robson

2010-01-01

310

Farmers and Pesticides  

NSDL National Science Digital Library

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

American Association for the Advancement of Science (; )

2006-05-23

311

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

PubMed Central

Poloxamers (known by the trade name Pluronic®) are triblock copolymer surfactants that contain two polyethylene glycol blocks and one polypropylene glycol block of various sizes. Poloxamers are widely used as nanoparticle dispersants for nanotoxicity studies wherein nanoparticles are sonicated with a dispersant to prepare suspensions. It is known that poloxamers can be degraded during sonication and that reactive oxygen species contribute to the degradation process. However, the possibility that poloxamer degradation products are toxic to mammalian cells has not been well studied. We report here that aqueous solutions of poloxamer 188 (Pluronic® F-68) and poloxamer 407 (Pluronic® F-127) sonicated in the presence or absence of multi-walled carbon nanotubes (MWNTs) can became highly toxic to cultured cells. Moreover, toxicity correlated with the sonolytic degradation of the polymers. These findings suggest that caution should be used in interpreting the results of nanotoxicity studies where the potential sonolytic degradation of dispersants was not controlled. PMID:23030523

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

2013-01-01

312

Treatment of low level radioactive liquid waste containing appreciable concentration of TBP degraded products.  

PubMed

The acidic and alkaline low level radioactive liquid waste (LLW) generated during the concentration of high level radioactive liquid waste (HLW) prior to vitrification and ion exchange treatment of intermediate level radioactive liquid waste (ILW), respectively are decontaminated by chemical co-precipitation before discharge to the environment. LLW stream generated from the ion exchange treatment of ILW contained high concentrations of carbonates, tributyl phosphate (TBP) degraded products and problematic radio nuclides like (106)Ru and (99)Tc. Presence of TBP degraded products was interfering with the co-precipitation process. In view of this a modified chemical treatment scheme was formulated for the treatment of this waste stream. By mixing the acidic LLW and alkaline LLW, the carbonates in the alkaline LLW were destroyed and the TBP degraded products got separated as a layer at the top of the vessel. By making use of the modified co-precipitation process the effluent stream (1-2 ?Ci/L) became dischargeable to the environment after appropriate dilution. Based on the lab scale studies about 250 m(3) of LLW was treated in the plant. The higher activity of the TBP degraded products separated was due to short lived (90)Y isotope. The cement waste product prepared using the TBP degraded product was having good chemical durability and compressive strength. PMID:21920663

Valsala, T P; Sonavane, M S; Kore, S G; Sonar, N L; De, Vaishali; Raghavendra, Y; Chattopadyaya, S; Dani, U; Kulkarni, Y; Changrani, R D

2011-11-30

313

The ARS Pesticide Properties Database  

NSDL National Science Digital Library

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

2005-01-01

314

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.

315

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

PubMed

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

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

2004-01-15

316

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

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

Keinan, Alon

317

THE ROLE OF FORAGES IN REDUCING POVERTY AND DEGRADATION OF NATURAL RESOURCES IN TROPICAL PRODUCTION SYSTEMS  

Microsoft Academic Search

The paper reviews the role of forage crops in improving the productivity of smallholder farming systems and breaking the cycle of poverty and resource degradation. It reviews the contributions of forage crops to increasing farm incomes, intensifying farm production, and contributing to better human nutrition. Several case studies are presented, including mucuna in Central America and West Africa, the forage

M. Peters; P. Horne; A. Schmidt; F. Holmann; P. C. Kerridge; S. A. Tarawali; R. Schultze-Kraft; C. E. Lascano; P. Argel; W. Stür; S. Fujisaka; K. Müller-Sämann; C. Wortmann

318

Bridging the gap between life cycle inventory and impact assessment for toxicological assessments of pesticides used in crop production.  

PubMed

In Life Cycle Assessment (LCA), the Life Cycle Inventory (LCI) provides emission data to the various environmental compartments and Life Cycle Impact Assessment (LCIA) determines the final distribution, fate and effects. Due to the overlap between the Technosphere (anthropogenic system) and Ecosphere (environment) in agricultural case studies, it is, however, complicated to establish what LCI needs to capture and where LCIA takes over. This paper aims to provide guidance and improvements of LCI/LCIA boundary definitions, in the dimensions of space and time. For this, a literature review was conducted to provide a clear overview of available methods and models for both LCI and LCIA regarding toxicological assessments of pesticides used in crop production. Guidelines are provided to overcome the gaps between LCI and LCIA modeling, and prevent the overlaps in their respective operational spheres. The proposed framework provides a starting point for LCA practitioners to gather the right data and use the proper models to include all relevant emission and exposure routes where possible. It is also able to predict a clear distinction between efficient and inefficient management practices (e.g. using different application rates, washing and rinsing management, etc.). By applying this framework for toxicological assessments of pesticides, LCI and LCIA can be directly linked, removing any overlaps or gaps in between the two distinct LCA steps. PMID:24314898

van Zelm, Rosalie; Larrey-Lassalle, Pyrène; Roux, Philippe

2014-04-01

319

Development of phage immuno-loop-mediated isothermal amplification assays for organophosphorus pesticides in agro-products.  

PubMed

Two immuno-loop-mediated isothermal amplification assays (iLAMP) were developed by using a phage-borne peptide that was isolated from a cyclic eight-peptide phage library. One assay was used to screen eight organophosphorus (OP) pesticides with limits of detection (LOD) between 2 and 128 ng mL(-1). The iLAMP consisted of the competitive immuno-reaction coupled to the LAMP reaction for detection. This method provides positive results in the visual color of violet, while a negative response results in a sky blue color; therefore, the iLAMP allows one to rapidly detect analytes in yes or no fashion. We validated the iLAMP by detecting parathion-methyl, parathion, and fenitrothion in Chinese cabbage, apple, and greengrocery, and the detection results were consistent with the enzyme-linked immunosorbent assay (ELISA). In conclusion, the iLAMP is a simple, rapid, sensitive, and economical method for detecting OP pesticide residues in agro-products with no instrumental requirement. PMID:25135320

Hua, Xiude; Yin, Wei; Shi, Haiyan; Li, Ming; Wang, Yanru; Wang, Hong; Ye, Yonghao; Kim, Hee Joo; Gee, Shirley J; Wang, Minghua; Liu, Fengquan; Hammock, Bruce D

2014-08-19

320

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

Microsoft Academic Search

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

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

2003-01-01

321

R-(?)-mandelic acid production from racemic mandelic acids by Pseudomonas polycolor with asymmetric degrading activity  

Microsoft Academic Search

The microbial asymmetric degradation of S-(+)-mandelic acid was investigated in order to develop a practical process for R-(?)-mandelic acid production from racemic mandelic acids. Among the 790 culture strains tested, microorganisms belonging to the Brevibacterium, Pseudomonas, Rhodococcus, Rhodotorula, Rhodosporidium, Sporobolomyces and Gibberella genera exhibited high S-(+)-mandelic acid degrading activity. Pseudomonas polycolor IFO 3918 was determined to be the best strain

Eiji Takahashi; Katsuhiko Nakamichi; Masakatsu Furui; Takao Mori

1995-01-01

322

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

Microsoft Academic Search

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%).

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

2009-01-01

323

Degradation products of cyanidin glycosides from tart cherries and their bioactivities.  

PubMed

The bioactive anthocyanins present in tart cherries, Prunus cerasus L. (Rosaceae) cv. Balaton, are cyanidin 3-glucosylrutinoside (1), cyanidin 3-rutinoside (2), and cyanidin 3-glucoside (3). Cyanidin (4) is the major anthocyanidin in tart cherries. In our continued evaluation of the in vivo and in vitro efficacy of these anthocyanins to prevent inflammation and colon cancer, we have added these compounds to McCoy's 5A medium in an effort to identify their degradation products during in vitro cell culture studies. This resulted in the isolation and characterization of protocatechuic acid (5), the predominant degradation product. In addition, 2,4-dihydroxybenzoic acid (6) and 2,4,6-trihydroxybenzoic acid (7) were identified as degradation products. However, these degradation products were not quantified. Compounds 5-7 were also identified as degradation products when anthocyanins were subjected to varying pH and thermal conditions. In cyclooxygenase (COX)-I and -II enzyme inhibitory assays, compounds 5-7 did not show significant activities when compared to the NSAIDs Naproxen, Celebrex, and Vioxx, or Ibuprofen, at 50 microM concentrations. However, at a test concentration of 50 microM, the antioxidant activity of protocatechuic acid (5) was comparable to those of the commercial antioxidants tert-butylhydroquinone (TBHQ), butylated hydroxytoluene (BHT), and butylated hydroxyanisole (BHA), and superior to that of vitamin E at 10 microM concentrations. PMID:11600045

Seeram, N P; Bourquin, L D; Nair, M G

2001-10-01

324

Determination of pesticides associated with suspended sediments in the San Joaquin River, California, USA, using gas chromatography-ion trap mass spectrometry  

USGS Publications Warehouse

An analytical method useful for the quantification of a range of pesticides and pesticide degradation products associated with suspended sediments was developed by testing a variety of extraction and cleanup schemes. The final extraction and cleanup methods chosen for use are suitable for the quantification of the listed pesticides using gas chromatography-ion trap mass spectrometry and the removal of interfering coextractable organic material found in suspended sediments. Methylene chloride extraction followed by Florisil cleanup proved most effective for separation of coextractives from the pesticide analytes. Removal of elemental sulfur was accomplished with tetrabutylammonium hydrogen sulfite. The suitability of the method for the analysis of a variety of pesticides was evaluated, and the method detection limits (MDLs) were determined (0.1-6.0 ng/g dry weight of sediment) for 21 compounds. Recovery of pesticides dried onto natural sediments averaged 63%. Analysis of duplicate San Joaquin River suspended-sediment samples demonstrated the utility of the method for environmental samples with variability between replicate analyses lower than between environmental samples. Eight of 21 pesticides measured were observed at concentrations ranging from the MDL to more than 80 ng/g dry weight of sediment and exhibited significant temporal variability. Sediment-associated pesticides, therefore, may contribute to the transport of pesticides through aquatic systems and should be studied separately from dissolved pesticides.

Bergamaschi, B.A.; Baston, D.S.; Crepeau, K.L.; Kuivila, K.M.

1999-01-01

325

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

USGS Publications Warehouse

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

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

2006-01-01

326

Glycolysis-dependent histone deacetylase 4 degradation regulates inflammatory cytokine production  

PubMed Central

Activation of the inflammatory response is accompanied by a metabolic shift to aerobic glycolysis. Here we identify histone deacetylase 4 (HDAC4) as a new component of the immunometabolic program. We show that HDAC4 is required for efficient inflammatory cytokine production activated by lipopolysaccharide (LPS). Surprisingly, prolonged LPS treatment leads to HDAC4 degradation. LPS-induced HDAC4 degradation requires active glycolysis controlled by GSK3? and inducible nitric oxide synthase (iNOS). Inhibition of GSK3? or iNOS suppresses nitric oxide (NO) production, glycolysis, and HDAC4 degradation. We present evidence that sustained glycolysis induced by LPS treatment activates caspase-3, which cleaves HDAC4 and triggers its degradation. Of importance, a caspase-3–resistant mutant HDAC4 escapes LPS-induced degradation and prolongs inflammatory cytokine production. Our findings identify the GSK3?-iNOS-NO axis as a critical signaling cascade that couples inflammation to metabolic reprogramming and a glycolysis-driven negative feedback mechanism that limits inflammatory response by triggering HDAC4 degradation. PMID:25187650

Wang, Bin; Liu, Ting-yu; Lai, Chun-Hsiang; Rao, Yan-hua; Choi, Moon-Chang; Chi, Jen-Tsan; Dai, Jian-wu; Rathmell, Jeffrey C.; Yao, Tso-Pang

2014-01-01

327

Photocatalytic degradation of molinate in aqueous solutions.  

PubMed

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

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

2014-11-01

328

The Need for Strategic Environmental Assessment of Fishery Products Regulations in the Taiwan Strait: Taking Health Perspectives of Organochlorine Pesticides in Seafood as an Example  

Microsoft Academic Search

This article proposes an integrated Health Impact Assessment\\/Strategic Environmental Assessment (HIA\\/SEA) framework that can be applied to fishery products regulations in Taiwan Strait. In recent years, many studies with regards to organochlorine pesticides (OCPs), especially DDT and its derivatives, in Taiwan's environment and aquatic biota indicated that DDT, DDD, and DDE in seafood, especially oysters, in the Kinmen, Manchu area

Ming-Lone Liou; Shin-Cheng Yeh; Yong-Chien Ling; Chien-Min Chen

2006-01-01

329

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

Microsoft Academic Search

Monitoring and analysis of trace contaminants such as pharmaceuticals and pesticides require the preservation of the samples before they can be quantified using the appropriate analytical methods. Our objective is to determine the sample shelf life to insure proper quantification of ultratrace contaminants. To this end, we tested the stability of a variety of pharmaceutical products including caffeine, natural steroids,

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

2010-01-01

330

Environmental, biochemical and genetic drivers of DMSP degradation and DMS production in the Sargasso Sea.  

PubMed

Dimethylsulfide (DMS) is a climatically relevant trace gas produced and cycled by the surface ocean food web. Mechanisms driving intraannual variability in DMS production and dimethylsulfoniopropionate (DMSP) degradation in open-ocean, oligotrophic regions were investigated during a 10-month time-series at the Bermuda Atlantic Time-series Study site in the Sargasso Sea. Abundance and transcription of bacterial DMSP degradation genes, DMSP lyase enzyme activity, and DMS and DMSP concentrations, consumption rates and production rates were quantified over time and depth. This interdisciplinary data set was used to test current hypotheses of the role of light and carbon supply in regulating upper-ocean sulfur cycling. Findings supported UV-A-dependent phytoplankton DMS production. Bacterial DMSP degraders may also contribute significantly to DMS production when temperatures are elevated and UV-A dose is moderate, but may favour DMSP demethylation under low UV-A doses. Three groups of bacterial DMSP degraders with distinct intraannual variability were identified and niche differentiation was indicated. The combination of genetic and biochemical data suggest a modified 'bacterial switch' hypothesis where the prevalence of different bacterial DMSP degradation pathways is regulated by a complex set of factors including carbon supply, temperature and UV-A dose. PMID:22324779

Levine, Naomi Marcil; Varaljay, Vanessa A; Toole, Dierdre A; Dacey, John W H; Doney, Scott C; Moran, Mary Ann

2012-05-01

331

Biodegradation of organophosphorus pesticides by soil bacteria  

NASA Astrophysics Data System (ADS)

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.

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

2009-04-01

332

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

PubMed Central

We include in this review an assessment of the formation, environmental fate, and mammalian and ecotoxicity of CW agent degradation products relevant to environmental and occupational health. These parent CW agents include several vesicants: sulfur mustards [undistilled sulfur mustard (H), sulfur mustard (HD), and an HD/agent T mixture (HT)]; nitrogen mustards [ethylbis(2-chloroethyl)amine (HN1), methylbis(2-chloroethyl)amine (HN2), tris(2-chloroethyl)amine (HN3)], and Lewisite; four nerve agents (O-ethyl S-[2-(diisopropylamino)ethyl] methylphosphonothioate (VX), tabun (GA), sarin (GB), and soman (GD)); and the blood agent cyanogen chloride. The degradation processes considered here include hydrolysis, microbial degradation, oxidation, and photolysis. We also briefly address decontamination but not combustion processes. Because CW agents are generally not considered very persistent, certain degradation products of significant persistence, even those that are not particularly toxic, may indicate previous CW agent presence or that degradation has occurred. Of those products for which there are data on both environmental fate and toxicity, only a few are both environmentally persistent and highly toxic. Major degradation products estimated to be of significant persistence (weeks to years) include thiodiglycol for HD; Lewisite oxide for Lewisite; and ethyl methyl phosphonic acid, methyl phosphonic acid, and possibly S-(2-diisopropylaminoethyl) methylphosphonothioic acid (EA 2192) for VX. Methyl phosphonic acid is also the ultimate hydrolysis product of both GB and GD. The GB product, isopropyl methylphosphonic acid, and a closely related contaminant of GB, diisopropyl methylphosphonate, are also persistent. Of all of these compounds, only Lewisite oxide and EA 2192 possess high mammalian toxicity. Unlike other CW agents, sulfur mustard agents (e.g., HD) are somewhat persistent; therefore, sites or conditions involving potential HD contamination should include an evaluation of both the agent and thiodiglycol. Images Figure 1 Figure 3 Figure 5 PMID:10585900

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

1999-01-01

333

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

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.

Parliman, D.J.

2001-01-01

334

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

PubMed

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

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

2015-01-01

335

ATMOSPHERIC REACTION PRODUCTS FROM HAZARDOUS AIR POLLUTANT DEGRADATION  

EPA Science Inventory

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

336

Phytoplankton toxicity of the antibiotic chlortetracycline and its UV light degradation products.  

PubMed

Two common freshwater phytoplankton species Microcystis aeruginosa and Scenedesmus obliquus were employed as test organisms to investigate the toxic effects of chlortetracycline widely used in human medicine and veterinary as antibiotic. Toxicity assays were performed into two parts: antibiotic toxicity test and antibiotic degraded products toxicity test. In general, chlortetracycline had significantly toxic effect on population growth and chlorophyll-a accumulation of two phytoplankton. Although M. aeruginosa had ability to grow after exposed to chlortetracycline at 0.5 mg L(-1), its photosynthesis function was also disrupted. Compared with the data in two phytoplankton species, the chlorophyceae was more sensitive than the cyanophyceae. The adverse effect on S. obliquus was stronger than that on M. aeruginosa with increasing concentrations. In addition, for M. aeruginosa, regardless of the UV light degradation time, the treated chlortetracycline also had adverse effect on population growth and chlorophyll-a accumulated. The degraded chlortetracycline under any treatment time was more toxic for S. obliquus than chlortetracycline itself excluding under 24 h. However, the correlation between the toxicity and degradation time was not clear and toxicity enhanced in fact did not follow the increase or decrease in degradation time. Our study showed that the antibiotic chlortetracycline and its degraded products had adverse effect on freshwater phytoplankton, the former has not been reported before and the latter has been overlooked in other research in the past. PMID:22341398

Guo, R X; Chen, J Q

2012-06-01

337

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

338

Polycyclic aromatic hydrocarbons degrading microflora in a tropical oil-production well.  

PubMed

The surrounding environment near Dagang oil-production well suffers polycyclic aromatic hydrocarbons (PAHs) pollution. In the present study, indigenous microorganisms capable of degrading PAHs were isolated and the efficiency of PAHs removal was investigated. Seven PAH-degrading strains were isolated with the ability to grow on naphthalene, phenanthrene, pyrene and fluorene. They belonged to the genus Pseudomonas, Bacillus and Rhodococcus. The strain having the highest degrading capacity for each PAH was selected by the screening test. The removal efficiency of PAHs was found to be in the order of naphthalene > fluorene > phenanthrene > pyrene. The kinetics of PAHs degradation was then followed by liquid chromatography determination and the results showed it conforms to a first-order reaction kinetic model. This study would be highly important for investigating the ability of microorganisms to utilize PAHs as growth substrates. PMID:25216932

Yu, Chan; Yao, Jun; Cai, Minmin; Yuan, Haiyan; Chen, Huilun; Ceccanti, Brunello

2014-11-01

339

Characterisation and comparison of the uptake of ionizable and polar pesticides, pharmaceuticals and personal care products by POCIS and Chemcatchers.  

PubMed

Growing concern about the environmental impact of ionizable and polar organic chemicals such as pesticides, pharmaceuticals and personal care products has lead to the inclusion of some in legislative and regulatory frameworks. It is expected that future monitoring requirements for these chemicals in aquatic environments will increase, along with the need for low cost monitoring and risk assessment strategies. In this study the uptake of 13 neutral and 6 ionizable pesticides, pharmaceuticals and personal care products by modified POCIS (with Strata™-X sorbent) and Chemcatchers™ (SDB-RPS or SDB-XC) was investigated under controlled conditions at pH = 6.5 for 26 days. The modified POCIS and Chemcatcher™ (SDB-RPS) samplers exhibited similar performance with the uptake of the majority of the 19 chemicals of interest categorised as linear over the 26 day deployment. Only a few ionized herbicides (picloram and dicamba) and triclosan showed negligible accumulation. Chemcatcher™ with SDB-XC sorbent performed relatively poorly with only carbamazepine having a linear accumulation profile, and 8 compounds showing no measurable accumulation. Differences in the uptake behavior of chemicals were not easily explained by their physico-chemical properties, strengthening the requirement for detailed calibration data. PES membranes accumulated significant amount of some compounds (i.e. triclosan and diuron), even after extended deployment (i.e. 26 days). At present there is no way to predict which compounds will demonstrate this behavior. Increasing membrane pore size from 0.2 to 0.45 ?m for Chemcatcher™ (SBD-RPS) caused an average increase in Rs of 24%. PMID:25208684

Kaserzon, S L; Hawker, D W; Kennedy, K; Bartkow, M; Carter, S; Booij, K; Mueller, J F

2014-11-01

340

Laccase production and wood degradation by Trametes hirsuta  

Microsoft Academic Search

The laccase production byT. hirsuta was better in lignin as compared to malt extract media. Tannic acid gave the best laccase yield out of different lignins,\\u000a phenolic compounds and sugars tested as substrates. The sugars proved to be good substrates for growth only. The role ofT. hirsuta in semisolid fermentation of sawdust was studied with reference to its capacity to

D. S. Arora; D. K. Sandhu

1984-01-01

341

Degradation of trichloronitromethane by iron water main corrosion products  

Microsoft Academic Search

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

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

2008-01-01

342

Cyanide Production and Degradation During Growth of Chromobacterium violaceum  

Microsoft Academic Search

Cyanogenesis by growing cultures of Chromobacterium violaceurn was stimulated by the inclusion of glycine and methionine in the growth medium. Increases in the ferrous ion and phosphate concentrations of the growth medium stimulated cyanide production. Chromobacterium violaceum possesses a number of cyanide-utilizing enzymes: P-cyano- alanine synthase, y-cyano-a-aminobutyric acid synthase and rhodanese. Studies on the activities of these enzymes in cell-free

PAUL B. RODGERS; CHRISTOPHER J. KNOWLES

1978-01-01

343

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

PubMed

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

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

2013-08-01

344

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

PubMed Central

To study mechanisms by which microorganisms oxidize thiophenic sulfur in coal, we tested bacterial cultures for the ability to degrade dibenzothiophene (DBT), DBT-5-oxide, and DBT-sulfone and to modify water-soluble coal products derived from Illinois no. 6 and Ugljevik coals. In yeast extract medium, the majority of selected isolates degraded DBT and accumulated DBT-5-oxide in culture fluids; all but one of the cultures degraded DBT-5-oxide, and none of them degraded DBT-sulfone. Elemental analysis data indicated that the microbial cultures were able to decrease the amount of sulfur in soluble coal products derived from Illinois no. 6 and Ugljevik coals. However, these data suggested that microbially mediated sulfur removal from soluble Ugljevik coal occurred by nonspecific mechanisms. That is, extensive degradation of the carbon structure was concurrent with the loss of sulfur. This conclusion was supported by X-ray photoelectron spectroscopic data which indicated that the reduced sulfur forms in the soluble Ugljevik coal product was not oxidized by microbial treatment. PMID:16348275

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

1990-01-01

345

Pesticide Residues in Food: Your Daily Dose.  

ERIC Educational Resources Information Center

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.…

Mott, Lawrie

1985-01-01

346

75 FR 40824 - Monosodium methanearsonate (MSMA); Cancellation Order for Certain Pesticide Registrations  

Federal Register 2010, 2011, 2012, 2013, 2014

...Cancellation Order for Certain Pesticide Registrations AGENCY: Environmental...of products containing the organic arsenical monosodium methanearsonate...last products containing this pesticide registered for use in the...INFORMATION CONTACT: Tom Myers, Pesticide Re-evaluation...

2010-07-14

347

Isolation and structure elucidation of degradation products in the potential anticancer drug PAC-1.  

PubMed

PAC-1 was subjected to acid degradation conditions at 80 degrees C for 10h. Four unknown degradation products were isolated from PAC-1 by semi-preparative high performance liquid chromatography using isocratic elution conditions. Based on the ESI-MS and NMR spectral data the structures of these four degradation products were characterized as 2-allyl-6-((E)-((E)-(2-hydroxy-3-(2-hydroxypropyl)benzylidene)hydrazono)methyl)phenol, 2-hydroxy-3-(2-propenyl)-[[2-hydroxy-3-(2-propenyl)phenyl]methylene]hydrazone, 6,6'-(1E,1'E)-hydrazine-1,2-diylidenebis(methan-1-yl-1-ylidene)bis(2-(2-hydroxypropyl)phenol) and 2-hydroxy-3-(2-hydroxypropyl)benzaldehyde. PMID:19889506

Song, Zhen; Chen, Xiaohui; Zhang, Di; Gong, Ping; Bi, Kaishun

2010-03-11

348

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

USGS Publications Warehouse

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

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

2000-01-01

349

Applying pesticides  

NSDL National Science Digital Library

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

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

2006-05-23

350

Pesticide Standards  

ERIC Educational Resources Information Center

The Environmental Protection Agency chose the American Society of Testing and Materials to develop standardized guidelines for pesticide registration. Since the numbers and uses of pesticides is so wide, establishing ecological and public health guidelines may be difficult. Strong industry and government representation might also hamper the…

Shea, Kevin P.

1976-01-01

351

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

PubMed Central

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

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

2009-01-01

352

Degradation of trichloronitromethane by iron water main corrosion products.  

PubMed

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

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

2008-04-01

353

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

PubMed

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

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

2014-04-30

354

Global sensitivity analysis for UNSATCHEM simulations of crop production with degraded waters  

Technology Transfer Automated Retrieval System (TEKTRAN)

One strategy for maintaining irrigated agricultural productivity in the face of diminishing resource availability is to make greater use of marginal quality waters and lands. A key to sustaining systems using degraded irrigation waters is salinity management. Advanced simulation models and decision ...

355

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

Technology Transfer Automated Retrieval System (TEKTRAN)

Meadowfoam (Limnanthes alba L.) is a herbaceous winter-spring annual grown as a commercial oilseed crop. The meal remaining after oil extraction from the seed contains up to 4% of the glucosinolate glucolimnanthin. Degradation of glucolimnanthin yields toxic breakdown products, and therefore the mea...

356

HYDROLOGIC CONDITIONS AFFECTING THE TROPOSPHERIC FLUX OF VINCLOZOLIN AND ITS DEGRADATION PRODUCTS  

EPA Science Inventory

A laboratory chamber was used to determine hydrologic conditions that lead to the tropospheric flux of a suspected anti-androgenic dicarboximide fungicide, vinclozolin (3-(3,5-dichlorophenyl)-5-methyl-5-vinyl-oxzoli-dine-2,4-dione) and three degradation products from sterilized...

357

Continuous production of lignin-degrading enzymes by Bjerkandera adusta immobilized on polyurethane foam  

Microsoft Academic Search

Continuous production of lignin-degrading enzymes by Bjerkandera adusta immobilized on polyurethane foam gave maximum activities of 220 U lignin peroxidase ml-1, 150 U manganese peroxidase ml-1, 50 U laccase ml-1 and 6.2 U protease ml-1 at the retention time of 24 h for 60 days. Protease secretion destabilized the produced lignin peroxidase, manganese peroxidase and laccase.

Godliving Mtui; Yoshitoshi Nakamura

2002-01-01

358

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

Microsoft Academic Search

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

Robin M Black; Bob Muir

2003-01-01

359

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

Microsoft Academic Search

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

Takafumi Ochi; Toshihide Suzuki; Hideo Isono; Toshikazu Kaise

2004-01-01

360

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

USGS Publications Warehouse

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.

Ferrer, I.; Barcelo, D.

2001-01-01

361

Repression and recuperation of brood production in Bombus terrestris bumble bees exposed to a pulse of the neonicotinoid pesticide imidacloprid.  

PubMed

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

Laycock, Ian; Cresswell, James E

2013-01-01

362

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

PubMed Central

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

Laycock, Ian; Cresswell, James E.

2013-01-01

363

Pesticides' influence on wine fermentation.  

PubMed

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

Caboni, Pierluigi; Cabras, Paolo

2010-01-01

364

The influence of lignin degradation products on xylose fermentation by Klebsiella pneumoniae  

Microsoft Academic Search

The inhibitory effects of seven closely related lignin degradation products on xylose fermentation by Klebsiella pneumoniae were studied. Compounds were added in varying concentrations. Less heavily substituted phenolics (at concentrations of, 0.1–0.4 g\\/l) were more inhibitory to growth and solvent production than vanillyl or syringyl derivatives. All of the cultures recovered from this inhibition after a prolonged incubation period. When

Nora K. Nishikawa; Roger Sutcliffe; John N. Saddler

1988-01-01

365

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

NASA Astrophysics Data System (ADS)

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.

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

2013-04-01

366

Acidic hydrolysis of bromazepam studied by high performance liquid chromatography. Isolation and identification of its degradation products  

Microsoft Academic Search

A kinetic study on the acidic hydrolysis of bromazepam was carried out in 0.01 M hydrochloric acid solution at 25 and 95°C. A reversed-phase HPLC method was developed and validated for the determination of bromazepam and its degradation products. Bromazepam degraded by a consecutive reaction with a reversible first step. Two degradation products were isolated and identified by infrared, 1H

I Panderi; H Archontaki; E Gikas; M Parissi-Poulou

1998-01-01

367

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

SciTech Connect

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.

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

1990-05-01

368

Reduction of hazardous organic solvent in sample preparation for hydrophilic pesticide residues in agricultural products with conventional liquid chromatography.  

PubMed

An original extraction method using water as an extractant has been established for environmentally friendly sample preparation procedures for hydrophilic pesticides (acetamiprid, clothianidin, dinotefuran, flonicamid, imidacloprid, methomyl, pymetrozine, thiacloprid, and thiamethoxam) in agricultural samples with conventional HPLC. Water-based extraction and cleanup with two solid-phase extraction cartridges can recover target hydrophilic pesticides quantitatively. The matrix effects of tested samples on the proposed method developed herein were negligibly small. Under the optimized conditions, the recoveries of almost all tested pesticides were 70-120% with satisfactory precision (%CV < 20%). The analytical data are in good accordance with Japanese or European Union guidelines for pesticide residue analysis. The reduction rate of hazardous organic solvents used for the proposed method and by reducing the sample size for extraction was about 70% compared with the Japanese authorized reference method used in this work. The results demonstrate the feasibility of the proposed sample preparation procedures for hydrophilic pesticides. PMID:23614723

Watanabe, Eiki; Kobara, Yuso; Baba, Koji; Eun, Heesoo

2013-05-22

369

Characterization of radiolytically generated degradation products in the strip section of a TRUEX flowsheet  

SciTech Connect

This report presents a summary of the work performed to meet the FCRD level 2 milestone M3FT-13IN0302053, “Identification of TRUEX Strip Degradation.” The INL radiolysis test loop has been used to identify radiolytically generated degradation products in the strip section of the TRUEX flowsheet. These data were used to evaluate impact of the formation of radiolytic degradation products in the strip section upon the efficacy of the TRUEX flowsheet for the recovery of trivalent actinides and lanthanides from acidic solution. The nominal composition of the TRUEX solvent used in this study is 0.2 M CMPO and 1.4 M TBP dissolved in n-dodecane and the nominal composition of the TRUEX strip solution is 1.5 M lactic acid and 0.050 M diethylenetriaminepentaacetic acid. Gamma irradiation of a mixture of TRUEX process solvent and stripping solution in the test loop does not adversely impact flowsheet performance as measured by stripping americium ratios. The observed increase in americium stripping distribution ratios with increasing absorbed dose indicates the radiolytic production of organic soluble degradation compounds.

Dean R. Peterman; Lonnie G. Olson; Gary S. Groenewold; Rocklan G. McDowell; Richard D. Tillotson; Jack D. Law

2013-08-01

370

Acetamide herbicides and their degradation products in ground water and surface water of the United States, 1993-2003  

USGS Publications Warehouse

During 1993 through 2003, the U.S. Geological Survey conducted a number of studies to investigate and document the occurrence, fate, and transport of acetamide herbicides and their degradation products in ground and surface water. As part of these studies, approximately 5,100 water samples were collected and analyzed for the acetamide parent herbicides acetochlor, alachlor, dimethenamid, flufenacet, and metolachlor and their degradation products ethanesulfonic acid, oxanilic acid, and sulfinyl acetic acid. During this period, various analytical methods were developed to detect and measure concentrations of acetamide herbicides and their degradation products in ground water and surface water. Results showed that the degradation products of acetamide herbicides in ground water were detected more frequently and occurred at higher concentrations than their parent compounds. Further study showed that the acetamide herbicides and their degradation products were detected more frequently in surface water than in ground water. In general, the parent compounds were detected at similar or greater frequencies than the degradation products in surface water. The developed methods and data were valuable for acquiring information about the occurrence, fate, and transport of the herbicides and their degradation products and the importance of analyzing for both parent compounds and their degradate products in water-quality studies.

Scribner, Elisabeth A.; Dietze, Julie E.; Thurman, Michael

2004-01-01

371

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

Microsoft Academic Search

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

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

2000-01-01

372

Light induced heterogeneous ozone processing on the pesticides adsorbed on silica particles  

NASA Astrophysics Data System (ADS)

In France, in 2010, the sales of pesticides reached 1.8 billion euros for 61 900 tons of active ingredients, positioning France as a first European consumer of pesticides, as reported by the European Crop Protection Association. About 19 million hectares of crops are sprayed annually with pesticides, i.e., 35% of the total surface area of France. This corresponds to an average pesticide dose of 3.2 kg ha-1. The consumption of herbicide and fungicide is favoured in comparison to the use of insecticides in France and the other European countries, as well. The partitioning of pesticides between the gas and particulate phases influences the atmospheric fate of these compounds such as their photo-chemical degradation. There is much uncertainty concerning the behavior of the pesticides in the atmosphere. Especially, there is a gap of knowledge concerning the degradation of the pesticides induced by heterogeneous reactions in absence and especially in presence of solar light. Considering that most of the pesticides currently used are semi-volatile, it is of crucial importance to investigate the heterogeneous reactivity of particulate pesticides with light and with atmospheric oxidants such as ozone and OH radical. The aim of the present work is to evaluate the light induced heterogeneous ozonation of suspended pesticide particles. 8 pesticides (cyprodinil, deltamethrin, difenoconazole, fipronil, oxadiazon, pendimethalin, permethrin and tetraconazole) were chosen for their physico-chemical properties and their concentration levels in the PACA (Région Provence-Alpes-Côte d'Azur) region, France. Silica particles with well-known properties were chosen as model particles of atmospheric relevance. Kinetic rate constants were determined to allow estimate the atmospheric lifetimes relating to ozone. The rate constants were determined as follows: k = (6.6 × 0.2) 10-19, (7.2 × 0.3) 10-19, (5.1 × 0.5) 10-19, (3.9 × 0.3) 10-19 [cm3 molecules-1 s-1] for Cyprodinil, delthamethrine, permethrine and pendimethaline, respectively. Concerning the other four pesticides under study i.e. difenoconazole, fipronil, oxadiazon and tetraconazole the obtained rate constants were extremely slow, < 3.9 10-19 [cm3 molecules-1 s-1]. In addition, we identified the condensed phase products in such heterogeneous reactions of ozone with the particulate pesticides by GC-MS coupled with the derivatization technique. The gas-phase products were followed on-line by PTR-MS-TOF. The obtained results will allow to recognize the impact of the pesticides and their degradation products on the human health, and to make recommendations in order to reduce population exposure to the pesticide plume. The results of this work will contribute to better describe and understand the pollution by phyto-sanitary products on the regional scale, which constitutes a necessary step in the development of environmental strategies. As a result the obtained results will help in the development of future environmental strategies to better understand and control phyto-sanitary product application and human exposure.

Socorro, J.; Désert, M.; Quivet, E.; Gligorovski, S.; Wortham, H.

2013-12-01

373

Analysis of degradation products of PAH and PCP using electrospray ionization mass spectrometry  

SciTech Connect

Bioremediation is an important strategy for the clean-up of hazardous waste sites. In the past, assessing the efficacy of bioremediation techniques has involved monitoring the disappearance of the pollutant with minimal regard to the products formed via microbial degradation of the initial contaminant. Aromatic hydrocarbons in the environment are subject to oxidation by a variety of mechanisms including photooxidation, microbial degradation and metabolism by higher organisms. These processes result in an array of oxygenated products including hydroxylated aromatics, ketones, quinones, and acids. In many animals, metabolically activated PAH bind covalently to cellular species including sulfate, glucuronic acid, glutathione, as well as proteins and DNA. In some cases, the oxygenated species have been shown to be more highly toxic than the parent hydrocarbon. Measures directed at either controlling the migration of toxic microbial metabolites, or precluding their formation in the first place, can be developed intelligently if the chemical characteristics of the toxic can be determined. It is, therefore, desirable to characterize fully the degradation products present in environmental samples not only as a means of elucidating the degradation pathways, but in order to assess the full hazard represented by the contamination and the effectiveness of the clean-up protocols employed. Conventional GC/MS techniques often require extensive sample clean-up and fractionation, while the more polar metabolites are intractable to GC altogether. Since electrospray ionization is well suited to analysis of such polar nonvolatile compounds, as well as compatible with HPLC clean-up and separations, the authors are applying this technique to the analysis of polar degradation products of aromatic hydrocarbons including polycyclic aromatic hydrocarbons and chlorinated phenols.

Pavlovich, J.G.; Stringfellow, W.; Kazunga, Chikoma; Aitken, M.D.; Charles, M.J. [Univ. of North Carolina, Chapel Hill, NC (United States)

1994-12-31

374

Biodegradation of Leonardite by an alkali-producing bacterial community and characterization of the degraded products.  

PubMed

In this study, three bacterial communities were obtained from 12 Leonardite samples with the aim of identifying a clean, effective, and economic technique for the dissolution of Leonardite, a type of low-grade coal, in the production of humic acid (HA). The biodegradation ability and characteristics of the degraded products of the most effective bacterial community (MCSL-2), which degraded 50% of the Leonardite within 21 days, were further investigated. Analyses of elemental composition, (13)C NMR, and Fourier transform infrared revealed that the contents of C, O, and aliphatic carbon were similar in biodegraded humic acid (bHA) and chemically (alkali) extracted humic acid (cHA). However, the N and carboxyl carbon contents of bHA was higher than that of cHA. Furthermore, a positive correlation was identified between the degradation efficiency and the increasing pH of the culture medium, while increases of manganese peroxidase and esterase activities were also observed. These data demonstrated that both alkali production and enzyme reactions were involved in Leonardite solubilization by MCSL-2, although the former mechanism predominated. No fungus was observed by microscopy. Only four bacterial phylotypes were recognized, and Bacillus licheniformis-related bacteria were identified as the main group in MCSL-2 by analysis of amplified 16S rRNA genes, thus demonstrating that Leonardite degradation ability has a limited distribution in bacteria. Hormone-like bioactivities of bHA were also detected. In this study, a bacterial community capable of Leonardite degradation was identified and the products characterized. These data implicate the use of such bacteria for the exploitation of Leonardite as a biofertilizer. PMID:22075634

Gao, Tong-Guo; Jiang, Feng; Yang, Jin-Shui; Li, Bao-Zhen; Yuan, Hong-Li

2012-03-01

375

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

PubMed

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

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

2013-03-01

376

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

PubMed Central

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

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

2014-01-01

377

Biodegradation of the alkaline cellulose degradation products generated during radioactive waste disposal.  

PubMed

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

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

2014-01-01

378

78 FR 21945 - Notice of Receipt of Pesticide Products; Registration Applications To Register New Uses  

Federal Register 2010, 2011, 2012, 2013, 2014

...Saflufenacil. Product Type: Herbicide. Proposed Uses: For use in rice paddies that are also used for aquaculture of fish and crayfish production. Contact: Bethany Benbow, (703) 347-8072, email address: benbow.bethany@epa.gov. 5. EPA...

2013-04-12

379

77 FR 65877 - Notice of Receipt of Pesticide Products; Registration Applications To Register New Uses  

Federal Register 2010, 2011, 2012, 2013, 2014

...provisions of section 3(c) of the Federal Insecticide, Fungicide, and Rodenticide Act...ingredient: Pyriproxyfen. Product Type: Insecticide. Proposed Uses: Bulb vegetable group...ingredient: Pyriproxyfen. Product Type: Insecticide. Proposed Uses: Bulb vegetable...

2012-10-31

380

78 FR 64937 - Pesticide Products; Registration Applications for New Active Ingredients  

Federal Register 2010, 2011, 2012, 2013, 2014

...Ave., Pasco, WA 99301. Active ingredient: Pseudomonas fluorescens strain D7. Product type: Herbicide. Proposed...Ave., Pasco, WA 99301. Active ingredient: Pseudomonas fluorescens strain D7. Product type: Herbicide....

2013-10-30

381

78 FR 9389 - Notice of Receipt of Pesticide Products; Registration Applications To Register New Uses  

Federal Register 2010, 2011, 2012, 2013, 2014

...Active ingredient: Methoxyfenozide. Product Type: Insecticide. Proposed Use...subgroups 13-07 A, F & G, sugar apple, cherimoya, atemoya, custard apple...Active ingredient: Aminopyralid. Product Type: Herbicide. Proposed...

2013-02-08

382

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

Federal Register 2010, 2011, 2012, 2013, 2014

...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:...

2012-09-26

383

PESTICIDE FORMULATING  

EPA Science Inventory

Resource Purpose: Developed to support effluent guidelines for the pesticide formulating, packaging, and repackaging industry. Data are used to develop environmental impacts, regulatory limits, and the cost of regulation. Legislation/Enabling Authority: CWA S...

384

Zinc chloride mediated degradation of cellulose at 200 °C and identification of the products  

PubMed Central

The effect of ZnCl2 on the degradation of cellulose was studied to develop conditions to produce useful feedstock chemicals directly from cellulosic biomass. Cellulose containing 0.5 mol of ZnCl2/mol of glucose unit of cellulose was found to degrade at 200 °C when heated for more than 60 s in air. The major non gaseous products of the degradation were identified as furfural, 5-hydroxymethylfurfural and levulinic acid. The maximum yields for furfural and 5-hydroxymethylfurfural are 8 and 9 % respectively based on glucose unit of cellulose. These yields are reached after 150 s of heating at 200 °C. A cellulose sample containing 0.5 mol of ZnCl2/mol of glucose unit of cellulose and 5.6 equivalents of water when heated for 150 s at 200 °C produced levulinic acid as the only product in 6% yield. The ZnCl2 mediated controlled degradation of cellulose at 200 °C is shown to produce useful feedstock chemicals in low yield. PMID:19540751

Amarasekara, Ananda S.; Ebede, Chidinma C.

2009-01-01

385

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

PubMed

Hexanitrohexaazaisowurtzitane (CL-20) is an emerging explosive that may replace the currently used explosives such as RDX and HMX, but little is known about its fate in soil. The present study was conducted to determine degradation products of CL-20 in two sandy soils under abiotic and biotic anaerobic conditions. Biotic degradation was prevalent in the slightly acidic VT soil, which contained a greater organic C content, while the slightly alkaline SAC soil favored hydrolysis. CL-20 degradation was accompanied by the formation of formate, glyoxal, nitrite, ammonium, and nitrous oxide. Biotic degradation of CL-20 occurred through the formation of its denitrohydrogenated derivative (m/z 393 Da) while hydrolysis occurred through the formation of a ring cleavage product (m/z 156 Da) that was tentatively identified as CH(2)=N-C(=N-NO(2))-CH=N-CHO or its isomer N(NO(2))=CH-CH=N-CO-CH=NH. Due to their chemical specificity, these two intermediates may be considered as markers of in situ attenuation of CL-20 in soil. PMID:18801604

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

2009-01-01

386

Use of liquid chromatography quadrupole time-of-flight mass spectrometry in the elucidation of transformation products and metabolites of pesticides. Diazinon as a case study  

Microsoft Academic Search

Liquid chromatography (LC) coupled to hybrid quadrupole time-of-flight (QTOF) mass spectrometry (MS) is a useful analytical\\u000a tool in the elucidation and confirmation of transformation products (TPs)\\/metabolites of pesticides with a wide range of polarity,\\u000a in both environmental and biological samples. Firstly, the versatility of LC allows the determination of very distinct TPs\\/metabolites\\u000a as chromatographic conditions can be easily changed and

María Ibáñez; Juan V. Sancho; Óscar J. Pozo; Félix Hernández

2006-01-01

387

Reduction of the enniatins A, A?, B, B? by an in vitro degradation employing different strains of probiotic bacteria: identification of degradation products by LC-MS-LIT.  

PubMed

The degradation of the Fusarium mycotoxins ENs by 9 bacterial strains characteristic of the gastrointestinal tract like Bb. longum, Bb. bifidum, Bb. breve, Bb. adolescentes, Lb. rhamnosus, Lb. casei-casei, S. termofilus, Lb. ruminis, Lb. casei and twenty two strains of Saccharomyces cerevisiae was studied. The fermentations were carried out in the liquid medium of De Man Rogosa Sharpe (MRS) under anaerobic conditions for Bifidobacteria Streptococcus and Lactobacillus, and in Potato Dextrose Broth (PDB) for Saccharomyces strains, during 48 h. The degradation of the bioactive compounds ENs was also studied in a food system composed by wheat flour naturally contaminated by ENs through fermentation by a strain of Fusarium tricinctum. The determination of the ENs in the fermentation mediums was performed using the technique of the liquid chromatography coupled to the mass spectrometry detector in tandem (LC-MS/MS), whereas the identification of the degradation products produced by microbial fermentation was carried out using the technique of the LC coupled to the linear ion trap (LIT). All the bacteria analyzed in this study showed a significant ENs reduction in vitro during the fermentation processes, with degradation data ranging from 5 to the 99%. In the food system, the ENs degradation data evidenced ranged from 1.3 to 49.2%. Also three ENs degradation products were identified. PMID:23587849

Roig, M; Meca, G; Ferrer, E; Mañes, J

2013-08-01

388

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

Federal Register 2010, 2011, 2012, 2013, 2014

...for a New Active Ingredient Chemical; Demiditraz AGENCY: Environmental Protection Agency...Kalamazoo, MI 49001. Product name: Demiditraz Technical. Active ingredient: Insecticide and Demiditraz at 100%. Proposed...

2010-02-09

389

Chromatographic separation of chlorophenoxy acid herbicides and their radiolytic degradation products in water samples.  

PubMed

HPLC procedure for simultaneous determination of chlorophenoxy acid herbicides and their radiolytic degradation products in waters is described with the use of octadecylsilica column and spectrophotometric detection at 280 nm. The satisfactory separation was achieved with a mobile phase of pH 2.5 consisting of 43.7 mM acetic acid with 40% (v/v) acetonitrile. Limit of detection values for herbicides and phenol derivatives were in the range of 19-41 microg/l and 10-60 microg/l, respectively. The developed method was applied for monitoring the effectiveness of radiolytic degradation of herbicides. Studies of products of gamma-radiolysis of 2,4-dichlorophenol have shown that the efficiency of this process is affected by the presence of naturally occurring scavengers of gamma-radiation such as carbonates or nitrates. PMID:15276742

Jankowska, A; Biesaga, M; Drzewicz, P; Trojanowicz, M; Pyrzy?ska, K

2004-01-01

390

Buthionine sulfoximine diverts the melanogenesis pathway toward the production of more soluble and degradable pigments.  

PubMed

Buthionine sulfoximine (BSO) is a specific inhibitor of ?-glutamylcysteine synthetase, thus blocking the synthesis of glutathione (GSH). It is known that this makes that BSO affects melanin synthesis because of the role of thiols in melanogenesis. However, BSO may also react with the intermediate oxidation products of melanogenesis, a possibility that has not been investigated from the initial steps of the pathway. We created in vitro conditions simulating eumelanogenesis (oxidation of L-DOPA in the absence of GSH) and pheomelanogenesis (oxidation of L-DOPA in the presence of GSH) under presence or absence of BSO. BSO made that eumelanogenesis results in pigments more soluble and less resistant to degradation by hydrogen peroxide than pigments obtained without BSO. A similar but less marked effect was observed for pheomelanogenesis only at subsaturating concentrations of GSH. These results suggest that BSO diverts the melanogenesis pathway toward the production of more soluble and degradable pigments. PMID:24703231

Galván, Ismael; Wakamatsu, Kazumasa; Alonso-Alvarez, Carlos; Solano, Francisco

2014-05-01

391

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

PubMed

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

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

392

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

NASA Astrophysics Data System (ADS)

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.

Gaßmann, Matthias; Olsson, Oliver; Bauer, Melanie

2010-05-01

393

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

NASA Astrophysics Data System (ADS)

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.

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

2012-06-01

394

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

Federal Register 2010, 2011, 2012, 2013, 2014

...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...

2012-09-26

395

Characterization of sucrose–glutamic acid Maillard products (SGMPs) degrading bacteria and their metabolites  

Microsoft Academic Search

Two aerobic bacteria RNBS1 and RNBS3 capable to degrade and utilize sucrose–glutamic acid Maillard products (SGMPs) as carbon, nitrogen and energy source were isolated and characterized as Alcaligenes faecalis (DQ659619) and Bacillus cereus (DQ659620) respectively by 16S rRNA gene sequence analysis. In present study, mixed bacterial culture was found more effective compared to axenic culture RNBS1 and RNBS3 decolourizing 73.79%,

Ram Chandra; Ram Naresh Bharagava; Vibhuti Rai; Shio Kumar Singh

2009-01-01

396

Determination of paper degradation by-products by direct injection on an HPLC column  

Microsoft Academic Search

The by-products of the thermal degradation of insulating paper include 2-furfural, 2-acetylfuran and 5-methyl-2-furfural. These furanic compounds are usually isolated by subjecting the insulating oil to a pretreatment stage on a silica solid-phase cartridge, or liquid-liquid extraction (IEC 1198) before analyzing them by high-performance liquid chromatography (HPLC). However, these procedures are time-consuming and not very practical. This paper describes an

M.-C. Lessard; C. Lamarre; A. Gendron; M. Masse

1995-01-01

397

Degradation and Metabolite Production of Tylosin in Anaerobic and Aerobic Swine-Manure Lagoons  

Microsoft Academic Search

Watershed contamination from antibiotics is becoming a critical issue because of increased numbers of confined animal-feeding operations and the use of antibiotics in animal production. To understand the fate of tylosin in manure before it is land-applied, degradation in manure lagoon slurries at 228C was studied. Tylosin disappearance followed a biphasic pattern, where rapid initial loss was followed by a

A. C. Kolz; T. B. Moorman; S. K. Ong; K. D. Scoggin; E. A. Douglass

398

Lignin-degrading enzyme production by Bjerkandera adusta immobilized on polyurethane foam  

Microsoft Academic Search

Production of the lignin-degrading enzymes lignin peroxidase (Lip), manganese peroxidase (MnP), and laccase (Lac) by the white-rot fungus Bjerkandera adusta was investigated experimentally using polyurethane foam (PUF) as a carrier of immobilized fungal mycelia. An immobilized cell culture with a low-nitrogen medium yielded significantly greater LiP, MnP, and Lac activities in comparison with those obtained in a liquid culture. The

Yoshitoshi Nakamura; Mtui Godliving Sungusia; Tatsuro Sawada; Masaaki Kuwahara

1999-01-01

399

Mass spectrometry of the products of the mechanochemical degradation of amylose macromolecules  

NASA Astrophysics Data System (ADS)

The destruction of amylose at high pressures (20 MPa) combined with shear deformations (540°) was studied. The destruction products were analyzed by mass spectrometry. The degradation of the polysaccharide caused by the extremal mechanical and mechanochemical treatment of amylose macromolecules was investigated. The formation of an appreciable amount of low-molecular oligomers was explained by the predominant cleavage of chains near the boundary zones of crystallites.

Kireeva, G. Kh.; Zhorin, V. A.; Razumovskii, S. D.; Varfolomeev, S. D.

2011-07-01

400

Body distribution of poly( d , l -lactide- co -glycolide) copolymer degradation products in rats  

Microsoft Academic Search

Poly (d,l-lactide-co-glycolide) (PLGA) copolymers are among the few synthetic polymers approved for human use, but the biocompatibility of PLGA-derived\\u000a oligomers and particles remains questionable. Here, high molecular weight PLGA (Mw = 32,000) was radiolabeled with 125I in chloroform solution, and the body distribution of PLGA copolymer degradation products was examined following subcutaneous\\u000a implantation of round 125I-PLGA films on the back of Sprague

Nan Hua; Jiao Sun

2008-01-01

401

By-products formation during degradation of isoproturon in aqueous solution. I: ozonation  

Microsoft Academic Search

The degradation of the herbicide isoproturon during its ozonation in aqueous solution has been investigated with the aim of identifying intermediate as well as final by-products formed. At ambient temperature, phosphate-buffered (pH=7) isoproturon aqueous solutions (10, 10?1 and 10?3mg\\/l) were ozonated in a semi-batch reactor, under a continuous flow of ozonated air whose ozone concentration was 9 and 0.9mgO3\\/lair for

Giuseppe mascolo; Antonio Lopez; Huw James; Mike Fielding

2001-01-01

402

Stability-indicating methods for determination of vincamine in presence of its degradation product  

Microsoft Academic Search

Three different stability indicating assay methods are developed and validated for determination of vincamine in the presence of its degradation product (vincaminic acid). The first method is based on the derivative ratio zero crossing spectrophotometric technique using 0.1N hydrochloric acid as a solvent. In the second method, measurements are based on spectro-densitometric technique using high performance thin-layer chromatography (HPTLC) plates

Mostafa A. M. Shehata; Mohammad A. El Sayed; Mohammad F. El Tarras; Mohammad G. El Bardicy

2005-01-01

403

“Zero-Tolerance” on Land Degradation for Sustainable Intensification of Agricultural Production  

Microsoft Academic Search

\\u000a The demand to improve soil health, arrest land degradation, in particular desertification in agro-ecosystems and protect land\\u000a and water resources for food production and sustainable agricultural and socio-economic development is expected to increase\\u000a in the next 50 years as a result of the continuing worldwide population growth and the increased reliance on limited natural\\u000a resource-based economy. Moreover, the intensive competition

Minh-Long Nguyen; Felipe Zapata; Gerd Dercon

404

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

Microsoft Academic Search

A method for the detection of hydrocarbon sterol degradation products (sterenes) has been adapted for the analysis of noncocoa\\u000a butter vegetable fats in chocolate. The method involves solvent extraction of the fat separation of the sterene fraction,\\u000a and analysis of individual sterenes with mass spectrometric detection. The sterene composition of refined noncocoa vegetable\\u000a fats was determined in samples of cocoa

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

1997-01-01

405

77 FR 66836 - Notice of Receipt of Pesticide Products; Registration Applications  

Federal Register 2010, 2011, 2012, 2013, 2014

...with Carob Moth Pheromone Mimic (7,9,11-Dodecatrien-1-ol, formate at 90.8%. Product Type: Pheromone (Mating Disruptor...with Carob Moth Pheromone Mimic (7,9,11-Dodecatrien-1-ol, formate at 2%. Product Type: Biochemical Pheromone....

2012-11-07

406

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

Technology Transfer Automated Retrieval System (TEKTRAN)

Stored product mites (Acari: Acaridida) can often infest stored products, but currently there is little information regarding efficacy of insecticides or miticides that can be used for control. In this study we evaluated several common insecticides (chlorpyrifos, deltametrhin, beta-cyfluthrin, and a...

407

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

PubMed Central

Gangliosides, sialic acid-containing glycosphingolipids, are membrane constituents of vertebrates and are known to have important roles in cellular differentiation, adhesion, and recognition. We report here the isolation of a bacterium capable of degrading gangliotetraose-series gangliosides and a new method for the production of glucosylceramide with this bacterium. GM1a ganglioside was found to be sequentially degraded by Paenibacillus sp. strain TS12, which was isolated from soil, as follows: GM1a ? asialo GM1 ? asialo GM2 ? lactosylceramide ? glucosylceramide. TS12 was found to produce a series of ganglioside-degrading enzymes, such as sialidases, ?-galactosidases, and ?-hexosaminidases. TS12 also produced ?-glucosidases, but glucosylceramide was somewhat resistant to the bacterial enzyme under the conditions used. Taking advantage of the specificity, we developed a new method for the production of glucosylceramide using TS12 as a biocatalyst. The method involves the conversion of crude bovine brain gangliosides to glucosylceramide by coculture with TS12 and purification of the product by chromatography with Wakogel C-300 HG. PMID:12406710

Sumida, Tomomi; Sueyoshi, Noriyuki; Ito, Makoto

2002-01-01

408

Bacterial degradation of chlorophenols and their derivatives  

PubMed Central

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

2014-01-01

409

Production of 5'-phosphodiesterase by Catharanthus roseus cells promoted by heat-degraded products generated from uronic acid.  

PubMed

Polyalginate was autoclaved at 121 degrees C for 20 min and its molecular weight distribution was analyzed. The autoclaved alginate yielded alginate polymer, oligomer and heat degraded products (HDPs). Each of the separated substances promoted 5'-phosphodiesterase (5'-PDase) production in suspension culture of Catharanthus roseus cells. HDPs could also be generated from other uronic acids (galacturonic acid and glucuronic acid) by autoclave treatment. The most effective substance in the HDPs was isolated and characterized as trans-4,5-dihydroxy-2-cyclopenten-1-one (DHCP). The optimal conditions for DHCP production were also established (autoclaving 1 mg/ml monogalacturonic acid [pH 2] at 121 degrees C for 2 h). A combination of oligo-alginate (below 4 kDa) and HDPs significantly promoted the production of 5'-PDase in C. roseus. Based on the above results, a novel alginate complex that gave a 44-fold increase in 5'-PDase production by C. roseus was developed. PMID:16233285

Akimoto-Tomiyama, Chiharu; Aoyagi, Hideki; Ozawa, Tetsuo; Tanaka, Hideo

2002-01-01

410

Fungicide dissipation and impact on metolachlor aerobic soil degradation and soil microbial dynamics  

Microsoft Academic Search

Pesticides are typically applied as mixtures and or sequentially to soil and plants during crop production. A common scenario is herbicide application at planting followed by sequential fungicide applications post-emergence. Fungicides depending on their spectrum of activity may alter and impact soil microbial communities. Thus there is a potential to impact soil processes responsible for herbicide degradation. This may change

Paul M. White; Thomas L. Potter; Albert K. Culbreath

2010-01-01

411

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)

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.

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

1999-01-01

412

77 FR 75152 - Notice of Receipt of Pesticide Products; Registration Applications  

Federal Register 2010, 2011, 2012, 2013, 2014

...at 5.25%. Product type: Plant Growth Regulator. Proposed use: Fruit color development/color enhancement on red apple varieties. Contact: Gina Burnett, BPPD, (703) 605-0513, email address: burnett.gina@epa.gov. List...

2012-12-19

413

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

Federal Register 2010, 2011, 2012, 2013, 2014

...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:...

2013-09-11

414

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

Federal Register 2010, 2011, 2012, 2013, 2014

...Applicant: Marrone Bio Innovations, 2121 Second St., Suite B-107, Davis, CA 95618. Active ingredient: Pseudomonas fluorescens strain CL145A cells and spent fermentation media. Product type: Molluscicide. Proposed uses:...

2013-12-26

415

78 FR 32245 - Notice of Receipt of Pesticide Products; Registration Applications To Register New Uses  

Federal Register 2010, 2011, 2012, 2013, 2014

...Fomesafen. Product Type: Herbicide. Proposed Use: Lima Beans. Contact: Michael Walsh, (703) 308- 2972, email address...Control of fleas, roaches, flies, mosquitoes, gnats, litter beetles, and ants on furniture, animal quarters, carpets,...

2013-05-29

416

77 FR 50686 - Pesticide Products; Receipt of Applications To Register New Uses  

Federal Register 2010, 2011, 2012, 2013, 2014

...use into fungicide products. Contact: Marcel Howard, (703) 305-6784, email address: howard.marcel@epa.gov. 15. Registration Number...Grass grown for hay and forage. Contact: Marcel Howard, (703) 305-6784, email...

2012-08-22

417

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

Federal Register 2010, 2011, 2012, 2013, 2014

...Suite 1050, Washington, DC 20005. Active ingredient: Bispyribac-sodium. Product type: Herbicide. Proposed uses: Athletic fields, commercial and residential turf. 7. EPA Registration Numbers: 71512-11 and 71512-18. Docket ID number:...

2013-12-18

418

75 FR 53691 - Pesticide Products; Registration Applications for a New Active Ingredient Chemical Sedaxane  

Federal Register 2010, 2011, 2012, 2013, 2014

...Greensboro, NC 27419-8300. Product name: A17511B. Active ingredients: Sedaxane, difenoconazole, mefenoxam, and thiamethoxam at .72%, 3.34%, .86% and 2.78% respectively. Proposal classification/Use: Fungicide/seed treatment...

2010-09-01

419

77 FR 30524 - Pesticide Products; Receipt of Applications To Register New Uses  

Federal Register 2010, 2011, 2012, 2013, 2014

...Greensboro, NC 27419. Active ingredient: Clodinafop-propargyl. Proposed Classification...formulation into technical and end-use herbicide products used on: Artichoke, Cabbage...44077. Active Ingredient: Flazasulfuron herbicide. Proposed Classification/Use:...

2012-05-23

420

78 FR 32246 - Pesticide Products; Registration Applications for New Active Ingredients  

Federal Register 2010, 2011, 2012, 2013, 2014

...products; nongrass animal feeds, forage, crop group 18; nongrass animal feeds, hay, crop group 18; coffee, bean, green; coffee, bean, roasted, instant; hops; peanut, hay; peanut, nutmeat; prickly pear cactus, fruit; pitaya,...

2013-05-29

421

78 FR 23558 - Pesticide Products; Registration Applications for New Active Ingredients  

Federal Register 2010, 2011, 2012, 2013, 2014

...CropScience LP, P.O. Box 12014, 2 T.W. Alexander Drive, Research Triangle Park, NC 27709. Active ingredient: Streptomyces microflavus strain AQ 6121. Product Type: e.g., Insecticide/Miticide. Proposed Uses: Terrestrial food crops....

2013-04-19

422

Oxidative degradation study on antimicrobial agent ciprofloxacin by electro-Fenton process: kinetics and oxidation products.  

PubMed

Oxidative degradation of the antimicrobial agent ciprofloxacin hydrochloride (CIP) has been investigated using electro-Fenton (EF) treatment with a constant current in the range 60-500 mA. The process generates highly oxidant species OH in situ via electrochemically monitored Fenton reaction. The EF experiments were performed using cells with a carbon felt cathode and Pt anode. Effect of applied current and catalyst concentration on the kinetics of oxidative degradation and mineralization efficiency have been investigated. Degradation of CIP followed pseudo-first order reaction kinetics. The rate constant of the oxidation of CIP by OH has been determined to be (1.01 ± 0.14) × 10(10) M(-1) s(-1) by using competitive kinetics method. An optimum current of 400 mA and a catalyst concentration of Fe(2+) at 0.1mM are found to be optimal for an effective degradation of CIP under our operating conditions. A remarkably high degree of mineralization (>94%) was obtained at 6h of treatment under these conditions. A number of stable intermediate products have been identified using HPLC and LC-MS/MS analyses. Based on the identified reaction intermediates, a plausible reaction pathway was proposed for the mineralization process. The high degree of mineralization obtained in this work highlights the potential application of EF process in the efficient removal of fluoroquinolone based drugs in aqueous medium. PMID:25201488

Yahya, Muna Sh; Oturan, Nihal; El Kacemi, Kacem; El Karbane, Miloud; Aravindakumar, C T; Oturan, Mehmet A

2014-12-01

423

Fractional factorial design optimization of the separation of pilocarpine and its degradation products by capillary electrophoresis.  

PubMed

The separation of pilocarpine and its degradation products by micellar electrokinetic capillary chromatography (MECC) has been optimized by using fractional factorial design of the experiments. Critical parameters were identified in a screening design, and an optimization design was used to optimize the separation. The optimal separation method was based on a borate buffer with sodium dodecyl sulfate (SDS). It is concluded that by using fractional factorial design it is possible to improve the separation of pilocarpine, its trans epimer, isopilocarpine and their hydrolysis products, pilocarpic acid and isopilocarpic acid. PMID:9342671

Persson, K; Aström, O

1997-09-12

424

Application of QuEChERS based method for the determination of pesticides in nutraceutical products (Camellia sinensis) by liquid chromatography coupled to triple quadrupole tandem mass spectrometry.  

PubMed

A QuEChERS (quick, easy, cheap, effective, rugged, and safe) based method has been evaluated and validated for the determination and quantification of approximately 100 LC-amenable pesticides in nutraceutical products obtained from green tea (Camellia sinensis). Extraction was performed with acidified acetonitrile (acetic acid 1% (v/v)), and additional clean-up steps were not necessary. Pesticides determination was achieved using ultra high performance liquid chromatography coupled to triple quadrupole tandem mass spectrometry (UHPLC-QqQ-MS/MS). Total running time was 11min. Pesticides were quantified using matrix-matched calibration. Recoveries ranged from 70% to 117% and relative standard deviation (RSD) was lower than 20% at concentration levels of 25, 50 and 100?g/kg for intra-day precision and equal or lower than 25% for inter-day precision. Limits of quantification (LOQ) were equal or lower than 25?g/kg. The validated method was applied to commercial nutraceutical products, detecting acetamiprid (56?g/kg) and carbendazim (13?g/kg) in two samples. PMID:25660875

Martínez-Domínguez, Gerardo; Nieto-García, Antonio José; Romero-González, Roberto; Frenich, Antonia Garrido

2015-06-15

425

Early diagenetic degradation products of bacteriohopanepolyols produced by Rhodopseudomonas palustris strain TIE-1  

NASA Astrophysics Data System (ADS)

The anoxygenic purple non-sulphur bacterium Rhodopseudomonas palustris strain TIE-1 has emerged as an excellent model organism to study hopanoid biosynthesis and function. It produces several C30 hopanoids, tetrahymanol, as well as various bacteriohopanepolyols (BHPs). In addition, TIE-1 is capable of methylating various hopanoids and the non-hopanoid pentacyclic terpenoid tetrahymanol at C-2, which is rare among hopanoid producers. Here, the lipid inventory of TIE-1 under anoxic photoautotrophic growth conditions using either H2 or Fe(II) as electron donor was studied. Adenosylhopane, aminotriol and bacteriohopanetetrol (BHT) were abundant when TIE-1 was grown on H2, but aminotriol and BHT were only found in traces when grown with Fe(II). Only during growth on Fe(II), BHT was found with and without C-2 methylation (25% of both BHT homologues), whereas the other BHPs were not C-2 methylated independent of growth mode. In C30 hopanoids and tetrahymanol, C-2 methylated compounds accounted for as much as 59% of the respective C-2 methylated/non-methylated homologues during growth with Fe(II), but only up to 24% during growth with H2. This observation reveals that C-2 methylated hopanoids may have a specific function in TIE-1 and are preferably synthesized in response to elevated Fe(II) concentrations. Further, we exposed the bacterial cells of strain TIE-1 to elevated temperatures and pressure aiming to produce early degradation products of bacteriohopanepolyols (BHPs). While so far, only few BHPs such as 32,35-anhydrobacteriohopanetetrol (anhydroBHT) have been identified as early diagenetic degradation products, in our experiments bacteriohopanetetrol (BHT) and possibly adenosylhopane were degraded to various anhydroBHT isomers, and new N-containing degradation products were discovered and tentatively assigned as anhydroaminotriols.

Eickhoff, Merle; Birgel, Daniel; Talbot, Helen M.; Peckmann, Jörn; Kappler, Andreas

2014-05-01

426

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

PubMed Central

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

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

427

A novel UV degradation product of Ebastine: Isolation and characterization using Q-TOF, NMR, IR and computational chemistry.  

PubMed

Forced degradation of Ebastine (1-(4-(1,1-dimethylethyl)phenyl)-4-(4-(diphenylmethoxy) piperidin-1-yl)butan-1-one) drug substance in ultraviolet light condition resulted into an unknown significant degradation product. This degradation product was analyzed using a newly developed reverse-phase HPLC, where it was eluted at 2.73 relative retention time to Ebastine peak. UV degradation product was isolated from reaction mass using preparative HPLC and its structure was elucidated using high resolution MS, multidimensional NMR and FTIR spectroscopic techniques. UV degradation product has been characterized as 2-(4-(benzhydryloxy)piperidin-1-yl)-1-(4-(tert-butyl)phenyl)-2-methylcyclopropanol. (1)H and (13)C NMR chemical shift values were generated using computational chemistry for possible two diastereomers (7R10S and 7R10R) and later 7R10R was confirmed (and its enantiomer) as final structure given it showed close agreement with experimental NMR data. Formation of UV degradation product as a recemic mixture was further verified by computational chemistry evaluation, chiral HPLC and polarimetery. To best of our knowledge, this is a novel degradation product which is not discussed at any form of publication yet. PMID:25679093

Rapolu, Ravi; Pandey, Avadhesh Kumar; Raju, Ch Krishnam; Ghosh, Kaushik; Srinivas, Kolupula; Awasthi, Atul; Navalgund, Sameer G; Surendranath, Koduru V

2015-03-25

428

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

NASA Astrophysics Data System (ADS)

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.

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

429

[Determination of the trace residues of four organochlorine pesticides in agricultural products by high performance liquid chromatography with modified multi-walled carbon nanotubes as solid phase extraction adsorbent].  

PubMed

A novel method for the simultaneous determination of the trace residues of four organochlorine pesticides such as p,p'-DDD, p,p'-DDT, o,p'-DDT and p,p'-DDE in agricultural products by multi-walled carbon nanotubes (MWNTs) modified by acid oxidation on the surface as solid phase extraction (SPE) adsorbent coupled with high performance liquid chromatography (HPLC) was developed. The effects of the surface acid oxidation, SPE operations and HPLC conditions on the determination of the four pesticide residues were investigated. Under the optimized experimental conditions, the novel method provided wide linear ranges for the pesticides with correlation coefficients of 0. 997 8 - 0. 999 5, the detection limit was 0.050 mg/L for each pesticides. The recoveries from the samples spiked with the pesticide standards at three concentration levels of 0.10, 2.0 and 50 mg/L were in the range of 78% - 104% with the relative standard deviations (RSDs) of 2.7% -7.6%. This study indicated the MWNTs SPE was an efficient clean-up method to agricultural products (included dried orange peel, ginseng, cabbage and tea). The proposed method showed the advantages of accuracy and sensitivity, and can meet the requirements for the determination of low residue pesticide in agricultural products. The study provides a useful method for the analysis of trace substance of agricultural products. PMID:23285982

Peng, Xiaojun; Pang, Jinshan; Deng, Aihua; Liang, Weihua; Liang, Youzhen; Wen, Qijing

2012-09-01

430

Advanced oxidation kinetics and mechanism of preservative propylparaben degradation in aqueous suspension of TiO2 and risk assessment of its degradation products.  

PubMed

The absolute kinetic rate constants of propylparaben (PPB) in water with different free radicals were investigated, and it was found that both hydroxyl radicals (HO(•)) and hydrated electrons could rapidly react with PPB. The advanced oxidation kinetics and mechanisms of PPB were investigated using photocatalytic process as a model technology, and the degradation was found to be a pseudo-first-order model. Oxidative species, particularly HO(•), were the most important reactive oxygen species mediating photocatalytic degradation of PPB, and PPB degradation was found to be significantly affected by pH because it was controlled by the radical reaction mechanism and was postulated to occur primarily via HO(•)-addition or H-abstraction reactions on the basis of pulse radiolysis measurements and observed reaction products. To investigate potential risk of PPB to humans and aqueous organisms, the estrogenic assays and bioassays were performed using 100 ?M PPB solution degraded by photocatalysis at specific intervals. The estrogenic activity decreased as PPB was degraded, while the acute toxicity at three trophic levels first increased slowly and then decreased rapidly as the total organic carbon decreased during photocatalytic degradation. PMID:23432079

Fang, Hansun; Gao, Yanpeng; Li, Guiying; An, Jibin; Wong, Po-Keung; Fu, Haiying; Yao, Side; Nie, Xiangping; An, Taicheng

2013-03-19

431

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

PubMed Central

Pyrene is a regulated pollutant at sites contaminated with polycyclic aromatic hydrocarbons (PAH). It is mineralized by some bacteria but is also transformed to nonmineral products by a variety of other PAH-degrading bacteria. We examined the formation of such products by four bacterial strains and identified and further characterized the most apparently significant of these metabolites. Pseudomonas stutzeri strain 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. PMID:10788360

Kazunga, Chikoma; Aitken, Michael D.

2000-01-01

432

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

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

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

2014-01-01

433

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

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

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

2014-01-01

434

Health Aspects of Organophosphorous Pesticides in Asian Countries  

PubMed Central

Organophosphorous (OP) pesticides are used frequently in agriculture, particularly in Asian countries over the past decades. Poisoning by these agents, either as acute or chronic in these nations, is a serious health problem. OP pesticides residue in fruits and vegetables that may not induce early clinical features, could also affect the human health. Therefore, medical and health professionals should be aware and learn more on the toxicology, prevention and proper management of OP poisoning. The well-known mechanism of OP toxicity is the inhibition of acetyl cholinesterase, resulting in an accumulation of acetylcholine and continued stimulation of acetylcholine receptors. Therefore, they are also called anticholinesterase agents. Determination of blood acetyl cholinesterase and butyryl cholinesterase activities remains a mainstay for the rapid initial screening of OP pesticides. Quantitative analysis of OP and their degradation products in plasma and urine by mass spectrometric methods is a more specific method, but is expensive and limited to specialized laboratories. Therefore, history of OP pesticides exposure and clinical manifestations of a cholinergic syndrome is sufficient for management of the exposed patients. However, electrophysiological tests may be required for the diagnosis of delayed neuropathy of OP poisoning. The standard management of OP poisoning includes decontamination, atropine sulphate with an oxime. Recent advances focus on blood alkalinisation and magnesium sulphate as promising adjunctive therapies. Preventive measures in OP exposure are of great importance in human health in developing countries. Therefore, regulations and controls on safe use of OP particularly in Asian countries are recommended. PMID:23304659

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

2012-01-01

435

Studies on in vitro degradation and in vivo digestion of a slow ammonia releasing urea product.  

PubMed

a slow ammonia releasing urea product (Uromalt) has been produced by autoclaving and drying of germinated barley and urea. In vitro degradability of nitrogen (IVDN, Raab et al., 1983) was in average 62 +/- 9% in 4 hours, compared to 76 +/- 8% with an autoclaved and dried mixture of urea and not-germinated barley. Mixtures of urea with Leucaena l. or Azadarichta indica (Neem cake) showed degradabilities of about 80 and 93%, respectively, when dried at 39 degrees C, but of 65% when dried at 100 degrees C. For comparison, degradabilities of proteins of ground nut, guar, sunflower, mustard, rape and sesame cake/meal have been determined. When growing lambs were fed a ration containing 15% Uromalt, faecal N-excretion was significantly higher on the expense of urinary N-excretion, compared with groups fed isonitrogenous rations containing soya bean meal with or without urea and molasses. N-retention was not significantly affected. It is concluded that this slow ammonia releasing urea product can be used in cases where molasses or other feedingstuffs rich in rapidly fermentable carbohydrates are not available. PMID:2735818

Virk, A S; Steingass, H; Menke, K H

1989-01-01

436

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

NASA Astrophysics Data System (ADS)

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.